Uncategorized

add_metadata_resolver

Deprecated: use decoder.metadata.add.

Type:

(string, ((metadata : [string * string], string) -> [string * string])) ->
unit

Arguments:

• (unlabeled) (of type string)
• (unlabeled) (of type (metadata : [string * string], string) -> [string * string])

add_playlist_parser

Deprecated: use playlist.parse.register instead

Type:

(name : string, mimes : [string], strict : bool,
 ((?pwd : string, string) -> [[string * string] * string])) -> unit

Arguments:

• name (of type string)
• mimes (of type [string])
• strict (of type bool)
• (unlabeled) (of type (?pwd : string, string) -> [[string * string] * string])

add_protocol

Deprecated: use protocol.add.

Type:

(?temporary : bool, ?static : ((string) -> bool), ?syntax : string,
 ?doc : string, string,
 ((rlog : ((string) -> unit), maxtime : float, string) -> string?)) -> unit

Arguments:

• temporary (of type bool, which defaults to false)
• static (of type (string) -> bool, which defaults to fun (_) -> false)
• syntax (of type string, which defaults to "Undocumented")
• doc (of type string, which defaults to "Undocumented")
• (unlabeled) (of type string)
• (unlabeled) (of type (rlog : ((string) -> unit), maxtime : float, string) -> string?)

add_timeout

Deprecated: this function has been replaced by thread.run.recurrent.

Type:

(?fast : bool, float, (() -> float)) -> unit

Arguments:

• fast (of type bool, which defaults to true)
• (unlabeled) (of type float)
• (unlabeled) (of type () -> float)

at

Deprecated: use at instead.

Type:

({bool}, source('a)) -> source('a)

Composition:

This source inherits composition from its effective source.

Arguments:

• (unlabeled) (of type {bool})
• (unlabeled) (of type source('a))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

audio_to_stereo

Deprecated: use source.stereo

Type:

(?id : string?, source(audio=pcm('a), 'b)) -> source(audio=pcm(stereo), 'b)
where 'b is a set of tracks to be muxed into a source

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• (unlabeled) (of type source(audio=pcm('a), 'b) where 'b is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source(audio=pcm(stereo), 'b), track_sensitive : bool}) -> unit where 'b is a set of tracks to be muxed into a source): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio=pcm(stereo), 'b)?, replay_metadata : bool, starting : source(audio=pcm(stereo), 'b) }) -> source(audio=pcm(stereo), 'b) where 'b is a set of tracks to be muxed into a source): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

base64.decode

Deprecated: this function has been replaced by string.base64.decode.

Type:

(string) -> string

Arguments:

• (unlabeled) (of type string)

base64.encode

Deprecated: this function has been replaced by string.base64.encode.

Type:

(string) -> string

Arguments:

• (unlabeled) (of type string)

compress.old

Deprecated: use compress

Type:

(?id : string?, source(audio=pcm('a), 'b)) ->
source(audio=pcm('a).{gain? : never, rms? : never}, 'b)
where 'b is a set of tracks to be muxed into a source

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• (unlabeled) (of type source(audio=pcm('a), 'b) where 'b is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• gain (of type () -> float)
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• rms (of type () -> float)
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ( { source : source(audio=pcm('a).{gain? : never, rms? : never}, 'b), track_sensitive : bool }) -> unit where 'b is a set of tracks to be muxed into a source): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio=pcm('a).{gain? : never, rms? : never}, 'b)?, replay_metadata : bool, starting : source(audio=pcm('a).{gain? : never, rms? : never}, 'b) }) -> source(audio=pcm('a).{gain? : never, rms? : never}, 'b) where 'b is a set of tracks to be muxed into a source): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

cue_cut

Deprecated: integrated into requests resolution.

Type:

(?id : string?, ?cue_in_metadata : string, ?cue_out_metadata : string,
 ?on_cue_in : (() -> unit), ?on_cue_out : (() -> unit), 'a) -> 'a

Arguments:

• id (of type string?, which defaults to "")
• cue_in_metadata (of type string, which defaults to "")
• cue_out_metadata (of type string, which defaults to "")
• on_cue_in (of type () -> unit, which defaults to {()})
• on_cue_out (of type () -> unit, which defaults to {()})
• (unlabeled) (of type 'a)

drop_audio

Deprecated: use source.drop.audio

Type:

(?id : string?, source(audio='a, 'b)) -> source(audio='a, 'b)
where 'b is a set of tracks to be muxed into a source

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• (unlabeled) (of type source(audio='a, 'b) where 'b is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source(audio='a, 'b), track_sensitive : bool}) -> unit where 'b is a set of tracks to be muxed into a source): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio='a, 'b)?, replay_metadata : bool, starting : source(audio='a, 'b) }) -> source(audio='a, 'b) where 'b is a set of tracks to be muxed into a source): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

drop_metadata

Deprecated: use source.drop.metadata

Type:

(?id : string?, source('a)) -> source('a)
where 'a is a set of tracks to be muxed into a source

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• (unlabeled) (of type source('a) where 'a is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit where 'a is a set of tracks to be muxed into a source): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a) where 'a is a set of tracks to be muxed into a source): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

drop_midi

Deprecated: use source.drop.midi

Type:

(?id : string?, source(midi='a, 'b)) -> source(midi='a, 'b)
where 'b is a set of tracks to be muxed into a source

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• (unlabeled) (of type source(midi='a, 'b) where 'b is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source(midi='a, 'b), track_sensitive : bool}) -> unit where 'b is a set of tracks to be muxed into a source): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(midi='a, 'b)?, replay_metadata : bool, starting : source(midi='a, 'b) }) -> source(midi='a, 'b) where 'b is a set of tracks to be muxed into a source): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

drop_video

Deprecated: use source.drop.video

Type:

(?id : string?, source(video='a, 'b)) -> source(video='a, 'b)
where 'b is a set of tracks to be muxed into a source

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• (unlabeled) (of type source(video='a, 'b) where 'b is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source(video='a, 'b), track_sensitive : bool}) -> unit where 'b is a set of tracks to be muxed into a source): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(video='a, 'b)?, replay_metadata : bool, starting : source(video='a, 'b) }) -> source(video='a, 'b) where 'b is a set of tracks to be muxed into a source): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

eat_blank

Deprecated: use blank.eat instead

Type:

(?id : string?, ?at_beginning : bool, ?max_blank : {float},
 ?min_noise : {float}, ?start_blank : bool, ?threshold : {float},
 ?track_sensitive : {bool}, source(audio=pcm('a), 'b)) ->
source(audio=pcm('a), 'b)

Composition:

This source inherits composition from its effective source.

Arguments:

• id (of type string?, which defaults to null)
• at_beginning (of type bool, which defaults to false)
• max_blank (of type {float}, which defaults to 20.0)
• min_noise (of type {float}, which defaults to 0.0)
• start_blank (of type bool, which defaults to false)
• threshold (of type {float}, which defaults to -40.0)
• track_sensitive (of type {bool}, which defaults to true)
• (unlabeled) (of type source(audio=pcm('a), 'b))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• dB_levels (of type () -> [float]?): Return the detected dB level for each channel.
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_blank (of type () -> bool): Indicate whether blank was detected.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source(audio=pcm('a), 'b), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio=pcm('a), 'b)?, replay_metadata : bool, starting : source(audio=pcm('a), 'b) }) -> source(audio=pcm('a), 'b)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

empty

Deprecated: this function has been replaced by source.fail.

Type:

(?id : string?) -> source('a)

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

exec_at

Deprecated: this function has been replaced by thread.when.

Type:

(?freq : float, pred : (() -> bool), (() -> 'a)) -> unit

Arguments:

• freq (of type float, which defaults to 1.0)
• pred (of type () -> bool)
• (unlabeled) (of type () -> 'a)

fade.final

Deprecated: was designed for transitions only and is not needed anymore. Use file.out instead.

Type:

(?id : string, ?duration : float, ?type : string, source(audio='a, 'b)) ->
source(audio='a, 'b)
where 'b is a set of tracks to be muxed into a source,
  'a is a track and a track of type: pcm, pcm_s16 or pcm_f32

Composition:

This source inherits composition from its effective source.

Arguments:

• id (of type string, which defaults to "fade.final")
• duration (of type float, which defaults to 3.0)
• type (of type string, which defaults to "lin")
• (unlabeled) (of type source(audio='a, 'b) where 'b is a set of tracks to be muxed into a source, 'a is a track and a track of type: pcm, pcm_s16 or pcm_f32)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• selected (of type () -> source(audio='a, 'b)? where 'b is a set of tracks to be muxed into a source, 'a is a track and a track of type: pcm, pcm_s16 or pcm_f32): Currently selected source.
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source(audio='a, 'b), track_sensitive : bool}) -> unit where 'b is a set of tracks to be muxed into a source, 'a is a track and a track of type: pcm, pcm_s16 or pcm_f32): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio='a, 'b)?, replay_metadata : bool, starting : source(audio='a, 'b) }) -> source(audio='a, 'b) where 'b is a set of tracks to be muxed into a source, 'a is a track and a track of type: pcm, pcm_s16 or pcm_f32): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

fade.initial

Deprecated: was designed for transitions only and is not needed anymore. Use fade.in instead.

Type:

(?id : string, ?duration : float, ?type : string, source(audio='a, 'b)) ->
source(audio='a, 'b)
where 'b is a set of tracks to be muxed into a source,
  'a is a track and a track of type: pcm, pcm_s16 or pcm_f32

Composition:

This source uses file composition by default.

Arguments:

• id (of type string, which defaults to "fade.initial")
• duration (of type float, which defaults to 3.0)
• type (of type string, which defaults to "lin")
• (unlabeled) (of type source(audio='a, 'b) where 'b is a set of tracks to be muxed into a source, 'a is a track and a track of type: pcm, pcm_s16 or pcm_f32)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source(audio='a, 'b), track_sensitive : bool}) -> unit where 'b is a set of tracks to be muxed into a source, 'a is a track and a track of type: pcm, pcm_s16 or pcm_f32): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio='a, 'b)?, replay_metadata : bool, starting : source(audio='a, 'b) }) -> source(audio='a, 'b) where 'b is a set of tracks to be muxed into a source, 'a is a track and a track of type: pcm, pcm_s16 or pcm_f32): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

fallback.skip

Deprecated: a source left mid-track is skipped by the file composition profile, so fallback on a fallback source with track_sensitive set to false does this natively.

Type:

(source('a).{track_sensitive : {bool}}, ?fallback : source('a)?) ->
source('a) where 'a is a set of internal tracks

Composition:

This source inherits composition from its effective source.

Arguments:

• (unlabeled) (of type source('a).{track_sensitive : {bool}} where 'a is a set of internal tracks): The main source.
• fallback (of type source('a)? where 'a is a set of internal tracks, which defaults to null): The fallback source. Defaults to blank if null.

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• selected (of type () -> source('a)? where 'a is a set of internal tracks): Currently selected source.
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit where 'a is a set of internal tracks): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a) where 'a is a set of internal tracks): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

file.unlink

Deprecated: use file.remove instead.

Type:

(string) -> unit

Arguments:

• (unlabeled) (of type string)

garbage_collect

Deprecated: use runtime.gc.full_major instead

Type:

() -> unit

get_mime

Deprecated: use file.mime

Type:

(string) -> string

Arguments:

• (unlabeled) (of type string)

get_process_lines

Deprecated: use process.read.lines instead.

Type:

(?timeout : float, ?env : [string * string], ?inherit_env : bool,
 ?log_errors : bool, string) -> [string]

Arguments:

• timeout (of type float, which defaults to -1.0)
• env (of type [string * string], which defaults to [])
• inherit_env (of type bool, which defaults to true)
• log_errors (of type bool, which defaults to true)
• (unlabeled) (of type string)

get_process_output

Deprecated: use process.read instead.

Type:

(?timeout : float, ?env : [string * string], ?inherit_env : bool,
 ?log_errors : bool, string) -> string

Arguments:

• timeout (of type float, which defaults to -1.0)
• env (of type [string * string], which defaults to [])
• inherit_env (of type bool, which defaults to true)
• log_errors (of type bool, which defaults to true)
• (unlabeled) (of type string)

getenv

Deprecated: use environment.get

Type:

(?string, string) -> string

Arguments:

• (unlabeled) (of type string, which defaults to "")
• (unlabeled) (of type string)

getpid

Deprecated: use getpid

Type:

() -> int

gettimeofday

Deprecated: use time instead

Type:

() -> float

gmtime

Deprecated: use time.utc instead

Type:

(float?) -> unit

Arguments:

• (unlabeled) (of type float?)

Methods:

• day (of type int): Day of month.
• dst (of type bool): Daylight time savings in effect.
• hour (of type int): Hours.
• min (of type int): Minutes.
• month (of type int): Month of year.
• sec (of type int): Seconds.
• week_day (of type int): Day of week (Sunday is 0 or 7, Saturday is 6).
• year (of type int): Year.
• year_day (of type int): Day of year, between 1 and 366.

https.delete

Deprecated: use http.delete instead.

Type:

(?headers : [string * string], ?http_version : string?, ?redirect : bool,
 ?timeout : float?, ?normalize_url : bool?, string) -> unit

Arguments:

• headers (of type [string * string], which defaults to [])
• http_version (of type string?, which defaults to null)
• redirect (of type bool, which defaults to true)
• timeout (of type float?, which defaults to 10.0)
• normalize_url (of type bool?, which defaults to null)
• (unlabeled) (of type string)

Methods:

• headers (of type [string * string]): HTTP headers.
• http_version (of type string): Version of the HTTP protocol.
• status_code (of type int): Status code.
• status_message (of type string): Status message.

https.get

Deprecated: use http.get instead.

Type:

(?headers : [string * string], ?http_version : string?, ?redirect : bool,
 ?timeout : float?, ?normalize_url : bool?, string) -> string

Arguments:

• headers (of type [string * string], which defaults to [])
• http_version (of type string?, which defaults to null)
• redirect (of type bool, which defaults to true)
• timeout (of type float?, which defaults to 10.0)
• normalize_url (of type bool?, which defaults to null)
• (unlabeled) (of type string)

Methods:

• headers (of type [string * string]): HTTP headers.
• http_version (of type string): Version of the HTTP protocol.
• status_code (of type int): Status code.
• status_message (of type string): Status message.

https.head

Deprecated: use http.head instead.

Type:

(?headers : [string * string], ?http_version : string?, ?redirect : bool,
 ?timeout : float?, ?normalize_url : bool?, string) -> unit

Arguments:

• headers (of type [string * string], which defaults to [])
• http_version (of type string?, which defaults to null)
• redirect (of type bool, which defaults to true)
• timeout (of type float?, which defaults to 10.0)
• normalize_url (of type bool?, which defaults to null)
• (unlabeled) (of type string)

Methods:

• headers (of type [string * string]): HTTP headers.
• http_version (of type string): Version of the HTTP protocol.
• status_code (of type int): Status code.
• status_message (of type string): Status message.

https.post

Deprecated: use http.post instead.

Type:

(?data : {string}, ?headers : [string * string], ?http_version : string?,
 ?redirect : bool, ?timeout : float?, ?normalize_url : bool?, string) ->
string

Arguments:

• data (of type {string}, which defaults to "")
• headers (of type [string * string], which defaults to [])
• http_version (of type string?, which defaults to null)
• redirect (of type bool, which defaults to true)
• timeout (of type float?, which defaults to 10.0)
• normalize_url (of type bool?, which defaults to null)
• (unlabeled) (of type string)

Methods:

• headers (of type [string * string]): HTTP headers.
• http_version (of type string): Version of the HTTP protocol.
• status_code (of type int): Status code.
• status_message (of type string): Status message.

https.put

Deprecated: use http.put instead.

Type:

(?data : {string}, ?headers : [string * string], ?http_version : string?,
 ?redirect : bool, ?timeout : float?, ?normalize_url : bool?, string) ->
string

Arguments:

• data (of type {string}, which defaults to "")
• headers (of type [string * string], which defaults to [])
• http_version (of type string?, which defaults to null)
• redirect (of type bool, which defaults to true)
• timeout (of type float?, which defaults to 10.0)
• normalize_url (of type bool?, which defaults to null)
• (unlabeled) (of type string)

Methods:

• headers (of type [string * string]): HTTP headers.
• http_version (of type string): Version of the HTTP protocol.
• status_code (of type int): Status code.
• status_message (of type string): Status message.

id

Deprecated: this function will be removed in a future release

Type:

(?id : 'a?, 'b) -> 'b

Arguments:

• id (of type 'a?, which defaults to null)
• (unlabeled) (of type 'b)

in

Deprecated: use input instead.

Type:

(?id : string?, ?start : bool, ?fallible : bool) -> source(audio=pcm('A))

Synchronization:

This source uses the PulseAudio clock as synchronization source when self_sync=true and the stream is open.

Composition:

This source uses live composition by default.

Arguments:

• id (of type string?, which defaults to null)
• start (of type bool, which defaults to true)
• fallible (of type bool, which defaults to false)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_started (of type () -> bool): true if the output or source is started.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string): This source uses the PulseAudio clock as synchronization source when self_sync=true and the stream is open.
• skip (of type () -> unit): Skip to the next track.
• start (of type () -> unit): Ask the source or output to start.
• stop (of type () -> unit): Ask the source or output to stop.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_start (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when source starts
• on_stop (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when source stops
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses live composition by default.
• on_leave (of type ({source : source(audio=pcm('A)), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio=pcm('A))?, replay_metadata : bool, starting : source(audio=pcm('A)) }) -> source(audio=pcm('A))): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

input.external

Deprecated: this function has been replaced by input.external.rawaudio.

Type:

(?id : string?, ?buffer : float, ?channels : int, ?max : float,
 ?restart : bool, ?restart_delay_on_error : float, ?restart_on_error : bool,
 ?samplerate : int, {string}) -> source(audio=pcm('a))

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• buffer (of type float, which defaults to 2.0)
• channels (of type int, which defaults to 2)
• max (of type float, which defaults to 10.0)
• restart (of type bool, which defaults to true)
• restart_delay_on_error (of type float, which defaults to 0.1)
• restart_on_error (of type bool, which defaults to false)
• samplerate (of type int, which defaults to 44100)
• (unlabeled) (of type {string})

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source(audio=pcm('a)), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio=pcm('a))?, replay_metadata : bool, starting : source(audio=pcm('a)) }) -> source(audio=pcm('a))): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

input.https

Deprecated: use input.http instead

Type:

(?id : string?, ?debug : bool, ?deduplicate_metadata : bool,
 ?float_args : [string * float], ?format : string?,
 ?int_args : [string * int], ?max_buffer : float,
 ?metadata_filter : (([string * string]) -> [string * string])?,
 ?new_track_on_metadata : bool, ?on_connect : (([string * string]) -> unit)?,
 ?on_disconnect : (() -> unit)?, ?on_error : ((error) -> unit)?,
 ?on_start : (() -> unit)?, ?on_stop : (() -> unit)?, ?poll_delay : float,
 ?self_sync : {bool?}, ?start : bool, ?string_args : [string * string],
 ?timeout : float, ?trim_url : bool, ?user_agent : string, {string}) ->
source('a)

Synchronization:

This source paces its clock while connected when self_sync is true.

Composition:

This source uses live composition by default.

Arguments:

• id (of type string?, which defaults to null)
• debug (of type bool, which defaults to false)
• deduplicate_metadata (of type bool, which defaults to true)
• float_args (of type [string * float], which defaults to [])
• format (of type string?, which defaults to null)
• int_args (of type [string * int], which defaults to [])
• max_buffer (of type float, which defaults to 5.0)
• metadata_filter (of type (([string * string]) -> [string * string])?, which defaults to null)
• new_track_on_metadata (of type bool, which defaults to true)
• on_connect (of type (([string * string]) -> unit)?, which defaults to null)
• on_disconnect (of type (() -> unit)?, which defaults to null)
• on_error (of type ((error) -> unit)?, which defaults to null)
• on_start (of type (() -> unit)?, which defaults to null)
• on_stop (of type (() -> unit)?, which defaults to null)
• poll_delay (of type float, which defaults to 2.0)
• self_sync (of type {bool?}, which defaults to null)
• start (of type bool, which defaults to true)
• string_args (of type [string * string], which defaults to [])
• timeout (of type float, which defaults to 10.0)
• trim_url (of type bool, which defaults to true)
• user_agent (of type string, which defaults to "Liquidsoap/2.5.0+git@86253d4 (Unix; OCaml 5.5.1)")
• (unlabeled) (of type {string})

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_started (of type () -> bool): true if the output or source is started.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string): This source paces its clock while connected when self_sync is true.
• set_url (of type ({string}) -> unit): Set the URL, used at the next connection.
• skip (of type () -> unit): Skip to the next track.
• start (of type () -> unit): Ask the source or output to start.
• status (of type () -> string): Status: "stopped", "starting", "polling", "connected <url>", "stopping" or "failed".
• stop (of type () -> unit): Ask the source or output to stop.
• time (of type () -> float): Get a source's time, based on its assigned clock.
• url (of type () -> string): Current URL.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_connect (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler when connected, before the source plays the connection's data.
• on_disconnect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when a connection whose on_connect callbacks ran ends.
• on_error (of type (synchronous : bool, ((error) -> unit)) -> {release : () -> unit}): Call a given handler on each connection or feeding failure.
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_start (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when source starts
• on_stop (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when source stops
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses live composition by default.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

insert_metadata

Deprecated: use the insert_metadata source method

Type:

(?id : 'a?, source('b)) -> source('b)

Arguments:

• id (of type 'a?, which defaults to null)
• (unlabeled) (of type source('b))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• on_leave (of type ({source : source('b), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('b)?, replay_metadata : bool, starting : source('b)}) -> source('b)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

json

Deprecated: use json.object

Type:

() -> json

Methods:

• add (of type (string, 'a) -> unit): Add or replace a new key/value pair to the object.
• remove (of type (string) -> unit): Remove a key from the object. Does not nothing if the key does not exist.
• stringify (of type (?compact : bool, ?json5 : bool) -> string): Render object as json string.

json_of

Deprecated: use json.stringify instead

Type:

(?compact : bool, ?json5 : bool, 'a) -> string

Arguments:

• compact (of type bool, which defaults to false): Output compact text.
• json5 (of type bool, which defaults to false): Use json5 extended spec.
• (unlabeled) (of type 'a)

list.mem_assoc

Deprecated: use list.assoc.mem instead

Type:

('a, ['a * 'b]) -> bool where 'a is an orderable type

Arguments:

• (unlabeled) (of type anything that is an orderable type)
• (unlabeled) (of type ['a * 'b] where 'a is an orderable type)

localtime

Deprecated: use time.local instead

Type:

(float?) -> unit

Arguments:

• (unlabeled) (of type float?)

Methods:

• day (of type int): Day of month.
• dst (of type bool): Daylight time savings in effect.
• hour (of type int): Hours.
• min (of type int): Minutes.
• month (of type int): Month of year.
• sec (of type int): Seconds.
• week_day (of type int): Day of week (Sunday is 0 or 7, Saturday is 6).
• year (of type int): Year.
• year_day (of type int): Day of year, between 1 and 366.

map_metadata

Deprecated: use metadata.map

Type:

(?id : string?, ?update : bool, ?strip : bool?, ?insert_missing : bool?,
 (([string * string]) -> [string * string]), source('a)) -> source('a)
where 'a is a set of tracks to be muxed into a source

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to "metadata.map")
• update (of type bool, which defaults to true)
• strip (of type bool?, which defaults to null)
• insert_missing (of type bool?, which defaults to null)
• (unlabeled) (of type ([string * string]) -> [string * string])
• (unlabeled) (of type source('a) where 'a is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit where 'a is a set of tracks to be muxed into a source): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a) where 'a is a set of tracks to be muxed into a source): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

merge_tracks

Deprecated: use source.tracks and source

Type:

(?id : string?, source('a)) -> source('a)
where 'a is a set of tracks to be muxed into a source

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• (unlabeled) (of type source('a) where 'a is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit where 'a is a set of tracks to be muxed into a source): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a) where 'a is a set of tracks to be muxed into a source): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

mkavailable

Deprecated: use source.available instead.

Type:

(?id : string, ?active : {bool}, ?available : {bool}, source('a)
 .{
   on_leave? : ({source : source('a), track_sensitive : bool}) -> unit,
   on_select? : (
                 {
                   ending : source('a)?,
                   replay_metadata : bool,
                   starting : source('a)
                 }) -> source('a),
   replay_metadata? : {bool},
   single? : bool,
   track_sensitive? : {bool}
 }) -> source('a)

Composition:

This source inherits composition from its effective source.

Arguments:

• id (of type string, which defaults to "mkavailable")
• active (of type {bool}, which defaults to false)
• available (of type {bool}, which defaults to true)
• (unlabeled) (of type source('a) .{ on_leave? : ({source : source('a), track_sensitive : bool}) -> unit, on_select? : ( { ending : source('a)?, replay_metadata : bool, starting : source('a) }) -> source('a), replay_metadata? : {bool}, single? : bool, track_sensitive? : {bool} })

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• selected (of type () -> source('a)?): Currently selected source.
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

mux_audio

Deprecated: use source.mux.audio.

Type:

(?id : string?, audio : source(audio='A, 'B), source('a)) ->
source(audio='A, 'a)
where 'a is a set of tracks to be muxed into a source, 'A is a track

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• audio (of type source(audio='B, 'A) where 'B is a track)
• (unlabeled) (of type source('a) where 'a is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source(audio='A, 'a), track_sensitive : bool}) -> unit where 'a is a set of tracks to be muxed into a source, 'A is a track): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio='A, 'a)?, replay_metadata : bool, starting : source(audio='A, 'a) }) -> source(audio='A, 'a) where 'a is a set of tracks to be muxed into a source, 'A is a track): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

mux_midi

Deprecated: use source.mux.midi

Type:

(?id : string?, midi : source(midi='A, 'B), source('a)) ->
source(midi='A, 'a)
where 'a is a set of tracks to be muxed into a source, 'A is a track

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• midi (of type source(midi='B, 'A) where 'B is a track)
• (unlabeled) (of type source('a) where 'a is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source(midi='A, 'a), track_sensitive : bool}) -> unit where 'a is a set of tracks to be muxed into a source, 'A is a track): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(midi='A, 'a)?, replay_metadata : bool, starting : source(midi='A, 'a) }) -> source(midi='A, 'a) where 'a is a set of tracks to be muxed into a source, 'A is a track): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

mux_video

Deprecated: use source.mux.video.

Type:

(?id : string?, video : source(video='A, 'B), source('a)) ->
source(video='A, 'a)
where 'a is a set of tracks to be muxed into a source, 'A is a track

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• video (of type source(video='B, 'A) where 'B is a track)
• (unlabeled) (of type source('a) where 'a is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source(video='A, 'a), track_sensitive : bool}) -> unit where 'a is a set of tracks to be muxed into a source, 'A is a track): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(video='A, 'a)?, replay_metadata : bool, starting : source(video='A, 'a) }) -> source(video='A, 'a) where 'a is a set of tracks to be muxed into a source, 'A is a track): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

of_json

Deprecated: use json.parse instead

Type:

(default : 'a, string) -> 'a

Arguments:

• default (of type 'a): Default value if string cannot be parsed.
• (unlabeled) (of type string)

on_blank

Deprecated: use blank.detect instead

Type:

(?id : string?, ?max_blank : {float}, ?min_noise : {float},
 ?start_blank : bool, ?threshold : {float}, ?track_sensitive : {bool},
 (() -> unit), source(audio=pcm('a), 'b)) -> source(audio=pcm('a), 'b)

Composition:

This source inherits composition from its effective source.

Arguments:

• id (of type string?, which defaults to null)
• max_blank (of type {float}, which defaults to 20.0)
• min_noise (of type {float}, which defaults to 0.0)
• start_blank (of type bool, which defaults to false)
• threshold (of type {float}, which defaults to -40.0)
• track_sensitive (of type {bool}, which defaults to true)
• (unlabeled) (of type () -> unit)
• (unlabeled) (of type source(audio=pcm('a), 'b))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• dB_levels (of type () -> [float]?): Return the detected dB level for each channel.
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_blank (of type () -> bool): Indicate whether blank was detected.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_blank (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when detecting a blank.
• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_noise (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when noise is detected.
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source(audio=pcm('a), 'b), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio=pcm('a), 'b)?, replay_metadata : bool, starting : source(audio=pcm('a), 'b) }) -> source(audio=pcm('a), 'b)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

on_metadata

Deprecated: use the on_metadata source method

Type:

(id : 'a, source('b), (([string * string]) -> unit)) -> source('b)

Arguments:

• id (of type 'a)
• (unlabeled) (of type source('b))
• (unlabeled) (of type ([string * string]) -> unit)

on_track

Deprecated: use the on_track source method

Type:

(id : 'a, source('b), (([string * string]) -> unit)) -> source('b)

Arguments:

• id (of type 'a)
• (unlabeled) (of type source('b))
• (unlabeled) (of type ([string * string]) -> unit)

out

Deprecated: use output instead.

Type:

(source(audio=pcm('A))) -> unit

Synchronization:

This output uses the PulseAudio clock as synchronization source when self_sync=true and the stream is open. Otherwise, the synchronization follows the underlying source.

Arguments:

• (unlabeled) (of type source(audio=pcm('A)))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_started (of type () -> bool): true if the output or source is started.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string): This output uses the PulseAudio clock as synchronization source when self_sync=true and the stream is open. Otherwise, the synchronization follows the underlying source.
• shutdown (of type () -> unit): Shutdown the output.
• skip (of type () -> unit): Skip to the next track.
• start (of type () -> unit): Ask the source or output to start.
• stop (of type () -> unit): Ask the source or output to stop.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_output (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on output. Unlike on_frame, this brackets the whole output cycle, encoding and sending included.
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_start (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when output starts
• on_stop (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when output stops
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

output.preferred

Type:

(?id : string?, ?fallible : bool, ?start : bool, source(audio=pcm('A))) ->
unit

Synchronization:

This output uses the PulseAudio clock as synchronization source when self_sync=true and the stream is open. Otherwise, the synchronization follows the underlying source.

Arguments:

• id (of type string?, which defaults to null)
• fallible (of type bool, which defaults to false)
• start (of type bool, which defaults to true)
• (unlabeled) (of type source(audio=pcm('A)))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_started (of type () -> bool): true if the output or source is started.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string): This output uses the PulseAudio clock as synchronization source when self_sync=true and the stream is open. Otherwise, the synchronization follows the underlying source.
• shutdown (of type () -> unit): Shutdown the output.
• skip (of type () -> unit): Skip to the next track.
• start (of type () -> unit): Ask the source or output to start.
• stop (of type () -> unit): Ask the source or output to stop.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_output (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on output. Unlike on_frame, this brackets the whole output cycle, encoding and sending included.
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_start (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when output starts
• on_stop (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when output stops
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

playlist.once

Deprecated: this function has been replaced with playlist, setting reload_mode argument to "never" and loop to false.

Type:

(?id : string?, ?random : bool, ?reload_mode : string, ?prefetch : int,
 ?filter : ((request) -> bool), string) -> source('a)

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• random (of type bool, which defaults to false)
• reload_mode (of type string, which defaults to "")
• prefetch (of type int, which defaults to 1)
• filter (of type (request) -> bool, which defaults to fun (_) -> true)
• (unlabeled) (of type string)

Methods:

• add (of type (request) -> bool): Add a request to the queue. Requests are resolved before being added. Returns true if the request was successfully added.
• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• current (of type () -> request?): Get the request currently being played.
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• fetch (of type () -> unit): Notify the source to queue a new request. If synchronous is false (the default), this method returns immediately and a new request is fetched in the background. If synchronous is true, can take long to return and should usually be run in a separate thread.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• length (of type () -> int)
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• queue (of type () -> [request]): Get the requests currently in the queue.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• reload (of type (?empty_queue : bool, ?uri : string?) -> unit)
• remaining (of type () -> float): Estimation of remaining time in the current track.
• remaining_files (of type () -> [string])
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• set_queue (of type ([request]) -> unit): Set the queue of requests. Requests are resolved before being added to the queue. You are responsible for destroying the requests currently in the queue.
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

playlist.reloadable

Deprecated: use playlist instead

Type:

(?id : string?, ?mime_type : string, ?mode : string,
 ?on_track : (() -> unit), ?prefix : string, ?reload : int,
 ?reload_mode : string, string) -> source('a)

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• mime_type (of type string, which defaults to "")
• mode (of type string, which defaults to "randomize")
• on_track (of type () -> unit, which defaults to {()})
• prefix (of type string, which defaults to "")
• reload (of type int, which defaults to 0)
• reload_mode (of type string, which defaults to "seconds")
• (unlabeled) (of type string)

Methods:

• add (of type (request) -> bool): Add a request to the queue. Requests are resolved before being added. Returns true if the request was successfully added.
• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• current (of type () -> request?): Get the request currently being played.
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• fetch (of type () -> unit): Notify the source to queue a new request. If synchronous is false (the default), this method returns immediately and a new request is fetched in the background. If synchronous is true, can take long to return and should usually be run in a separate thread.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• length (of type () -> int)
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• queue (of type () -> [request]): Get the requests currently in the queue.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• reload (of type (?empty_queue : bool, ?uri : string?) -> unit)
• remaining (of type () -> float): Estimation of remaining time in the current track.
• remaining_files (of type () -> [string])
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• set_queue (of type ([request]) -> unit): Set the queue of requests. Requests are resolved before being added to the queue. You are responsible for destroying the requests currently in the queue.
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

playlist.safe

Deprecated: use mksafe and playlist instead.

Type:

(?id : string?, ?mime_type : string, ?mode : string,
 ?on_track : (() -> unit), ?prefix : string, ?reload : int,
 ?reload_mode : string, string) -> source('a)
where 'a is a set of internal tracks

Composition:

This source inherits composition from its effective source.

Arguments:

• id (of type string?, which defaults to null)
• mime_type (of type string, which defaults to "")
• mode (of type string, which defaults to "randomize")
• on_track (of type () -> unit, which defaults to {()})
• prefix (of type string, which defaults to "")
• reload (of type int, which defaults to 0)
• reload_mode (of type string, which defaults to "seconds")
• (unlabeled) (of type string)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• selected (of type () -> source('a)? where 'a is a set of internal tracks): Currently selected source.
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit where 'a is a set of internal tracks): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a) where 'a is a set of internal tracks): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

quote

Deprecated: this function has been replaced by string.quote.

Type:

(string) -> string

Arguments:

• (unlabeled) (of type string)

replaygain

Deprecated: use normalize_track_gain

Type:

(?id : string?, source(audio='a, 'b)) -> source(audio='a, 'b)
where 'b is a set of tracks to be muxed into a source,
  'a is a track and a track of type: pcm, pcm_s16 or pcm_f32

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• (unlabeled) (of type source(audio='a, 'b) where 'b is a set of tracks to be muxed into a source, 'a is a track and a track of type: pcm, pcm_s16 or pcm_f32)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source(audio='a, 'b), track_sensitive : bool}) -> unit where 'b is a set of tracks to be muxed into a source, 'a is a track and a track of type: pcm, pcm_s16 or pcm_f32): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio='a, 'b)?, replay_metadata : bool, starting : source(audio='a, 'b) }) -> source(audio='a, 'b) where 'b is a set of tracks to be muxed into a source, 'a is a track and a track of type: pcm, pcm_s16 or pcm_f32): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

request.create.raw

Deprecated: use request.create instead.

Type:

(?cue_in_metadata : string?, ?cue_out_metadata : string?, ?persistent : bool,
 ?resolve_metadata : bool, ?excluded_metadata_resolvers : [string],
 ?temporary : bool, string) -> request

Arguments:

• cue_in_metadata (of type string?, which defaults to "liq_cue_in")
• cue_out_metadata (of type string?, which defaults to "liq_cue_out")
• persistent (of type bool, which defaults to false)
• resolve_metadata (of type bool, which defaults to true)
• excluded_metadata_resolvers (of type [string], which defaults to [])
• temporary (of type bool, which defaults to false)
• (unlabeled) (of type string)

request.dynamic.list

Deprecated: use request.dynamic instead

Type:

(?id : string?, ?available : {bool}, ?prefetch : int?,
 ?retry_delay : {float}, ?synchronous : bool, ?timeout : float?,
 ?native : bool, (() -> [request])) -> source('a)

Composition:

This source uses file composition by default.

Arguments:

• id (of type string?, which defaults to null)
• available (of type {bool}, which defaults to true)
• prefetch (of type int?, which defaults to null)
• retry_delay (of type {float}, which defaults to 0.1)
• synchronous (of type bool, which defaults to false)
• timeout (of type float?, which defaults to null)
• native (of type bool, which defaults to false)
• (unlabeled) (of type () -> [request])

Methods:

• add (of type (request) -> bool): Add a request to the queue. Requests are resolved before being added. Returns true if the request was successfully added.
• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• current (of type () -> request?): Get the request currently being played.
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• fetch (of type () -> unit): Notify the source to queue a new request. If synchronous is false (the default), this method returns immediately and a new request is fetched in the background. If synchronous is true, can take long to return and should usually be run in a separate thread.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• queue (of type () -> [request]): Get the requests currently in the queue.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• set_queue (of type ([request]) -> unit): Set the queue of requests. Requests are resolved before being added to the queue. You are responsible for destroying the requests currently in the queue.
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

request.ready

Deprecated: use request.resolved

Type:

(request) -> bool

Arguments:

• (unlabeled) (of type request)

rewrite_metadata

Deprecated: this function has been replaced by metadata.map.

Type:

([string * string], ?insert_missing : bool, ?update : bool, ?strip : bool,
 source('a)) -> source('a)
where 'a is a set of tracks to be muxed into a source

Composition:

This source uses file composition by default.

Arguments:

• (unlabeled) (of type [string * string])
• insert_missing (of type bool, which defaults to true)
• update (of type bool, which defaults to true)
• strip (of type bool, which defaults to false)
• (unlabeled) (of type source('a) where 'a is a set of tracks to be muxed into a source)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source uses file composition by default.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit where 'a is a set of tracks to be muxed into a source): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a) where 'a is a set of tracks to be muxed into a source): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

run_process

Deprecated: use process.run instead

Type:

(?env : [string * string], ?inherit_env : bool, ?stdin : string,
 ?rwdirs : [string], ?rodirs : [string], ?network : bool?, ?timeout : float?,
 string) -> string * string * (string * string)

Arguments:

• env (of type [string * string], which defaults to [])
• inherit_env (of type bool, which defaults to true)
• stdin (of type string, which defaults to "")
• rwdirs (of type [string], which defaults to ["default"])
• rodirs (of type [string], which defaults to ["default"])
• network (of type bool?, which defaults to null)
• timeout (of type float?, which defaults to null)
• (unlabeled) (of type string)

say_metadata

Deprecated: use source.say_metadata instead

Type:

(source('a), pattern : string) -> source('a) where 'a is an orderable type

Composition:

This source inherits composition from its effective source.

Arguments:

• (unlabeled) (of type source('a) where 'a is an orderable type)
• pattern (of type string)

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• cancel_pending (of type () -> unit)
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• pending (of type () -> source('a)? where 'a is an orderable type)
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• selected (of type () -> source('a)? where 'a is an orderable type): Currently selected source.
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• set_pending (of type (source('a)?) -> unit where 'a is an orderable type)
• skip (of type (?cancel_pending : bool) -> unit)
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source('a), track_sensitive : bool}) -> unit where 'a is an orderable type): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ({ending : source('a)?, replay_metadata : bool, starting : source('a)}) -> source('a) where 'a is an orderable type): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

setenv

Deprecated: use environment.set

Type:

(string, string) -> unit

Arguments:

• (unlabeled) (of type string)
• (unlabeled) (of type string)

skip_blank

Deprecated: use blank.skip instead

Type:

(?id : string?, ?threshold : float, ?max_blank : float, ?min_noise : float,
 ?track_sensitive : bool, source(audio=pcm('a), 'b)) ->
source(audio=pcm('a), 'b)

Composition:

This source inherits composition from its effective source.

Arguments:

• id (of type string?, which defaults to "blank.skip")
• threshold (of type float, which defaults to -40.0)
• max_blank (of type float, which defaults to 20.0)
• min_noise (of type float, which defaults to 0.0)
• track_sensitive (of type bool, which defaults to true)
• (unlabeled) (of type source(audio=pcm('a), 'b))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• dB_levels (of type () -> [float]?): Return the detected dB level for each channel.
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_blank (of type () -> bool): Indicate whether blank was detected.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_blank (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when detecting a blank.
• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_noise (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler when noise is detected.
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source(audio=pcm('a), 'b), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio=pcm('a), 'b)?, replay_metadata : bool, starting : source(audio=pcm('a), 'b) }) -> source(audio=pcm('a), 'b)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

sleep

Deprecated: use thread.pause

Type:

(float) -> unit

Arguments:

• (unlabeled) (of type float)

source.last_metadata

Deprecated: use the last_metadata source method

Type:

(id : 'a, source('b)) -> [string * string]?

Arguments:

• id (of type 'a)
• (unlabeled) (of type source('b))

source.on_end

Deprecated: use the on_position source method

Type:

(id : 'a, delay : {float}, source('b), ((float, [string * string]) -> unit)) ->
unit

Arguments:

• id (of type 'a)
• delay (of type {float})
• (unlabeled) (of type source('b))
• (unlabeled) (of type (float, [string * string]) -> unit)

Methods:

• release (of type () -> unit): Release the callback. Calling it more than once is a no-op.

source.on_frame

Deprecated: use the on_frame source method

Type:

(id : 'a, ?before : bool, source('b), (() -> unit)) -> unit

Arguments:

• id (of type 'a)
• before (of type bool, which defaults to true)
• (unlabeled) (of type source('b))
• (unlabeled) (of type () -> unit)

Methods:

• release (of type () -> unit): Release the callback. Calling it more than once is a no-op.

source.on_offset

Deprecated: use the on_position source method

Type:

(id : 'a, ?force : bool, offset : {float},
 ((float, [string * string]) -> unit), source('b)) -> unit

Arguments:

• id (of type 'a)
• force (of type bool, which defaults to false)
• offset (of type {float})
• (unlabeled) (of type (float, [string * string]) -> unit)
• (unlabeled) (of type source('b))

Methods:

• release (of type () -> unit): Release the callback. Calling it more than once is a no-op.

string.utf8.escape

Deprecated: this function has been replaced by string.escape.

Type:

(string) -> string

Arguments:

• (unlabeled) (of type string)

string_of

Deprecated: use string.

Type:

('a) -> string

Arguments:

• (unlabeled) (of type 'a)

string_of_float

Deprecated: use string.float.

Type:

(float) -> string

Arguments:

• (unlabeled) (of type float)

strip_blank

Deprecated: use blank.strip instead

Type:

(?id : string?, ?max_blank : {float}, ?min_noise : {float},
 ?start_blank : bool, ?threshold : {float}, ?track_sensitive : {bool},
 source(audio=pcm('a), 'b)) -> source(audio=pcm('a), 'b)

Composition:

This source inherits composition from its effective source.

Arguments:

• id (of type string?, which defaults to null)
• max_blank (of type {float}, which defaults to 20.0)
• min_noise (of type {float}, which defaults to 0.0)
• start_blank (of type bool, which defaults to false)
• threshold (of type {float}, which defaults to -40.0)
• track_sensitive (of type {bool}, which defaults to true)
• (unlabeled) (of type source(audio=pcm('a), 'b))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• dB_levels (of type () -> [float]?): Return the detected dB level for each channel.
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_blank (of type () -> bool): Indicate whether blank was detected.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source(audio=pcm('a), 'b), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(audio=pcm('a), 'b)?, replay_metadata : bool, starting : source(audio=pcm('a), 'b) }) -> source(audio=pcm('a), 'b)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

system

Deprecated: use process.run instead.

Type:

(string) -> unit

Arguments:

• (unlabeled) (of type string)

Methods:

• status (of type string.{code : int, description : string}): Status when process ended, can be one of "exit" (the program exited, the status code is then relevant), "killed" (the program was killed by signal given in status code), "stopped" (the program was stopped by signal given in status code) or "exception" (the program raised and exception detailed in the description).
• stderr (of type string): Messages written by process on standard error stream.
• stdout (of type string): Messages written by process on standard output stream.

test_process

Deprecated: use process.test instead.

Type:

(?timeout : float, ?env : [string * string], ?inherit_env : bool, string) ->
bool

Arguments:

• timeout (of type float, which defaults to -1.0)
• env (of type [string * string], which defaults to [])
• inherit_env (of type bool, which defaults to true)
• (unlabeled) (of type string)

video.line

Deprecated: use video.add_line.

Type:

(?id : string?, ?alpha : {float}, ?color : {int}, {int * int}, {int * int},
 source(video=yuv420p('a), 'b)) -> source(video=yuv420p('a), 'b)

Composition:

This source inherits composition from its effective source.

Arguments:

• id (of type string?, which defaults to null)
• alpha (of type {float}, which defaults to 1.0)
• color (of type {int}, which defaults to 0)
• (unlabeled) (of type {int * int})
• (unlabeled) (of type {int * int})
• (unlabeled) (of type source(video=yuv420p('a), 'b))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source(video=yuv420p('a), 'b), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(video=yuv420p('a), 'b)?, replay_metadata : bool, starting : source(video=yuv420p('a), 'b) }) -> source(video=yuv420p('a), 'b)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

video.rectangle

Deprecated: use video.add_rectangle.

Type:

(?id : string?, ?alpha : {float}, ?color : {int}, height : {int},
 width : {int}, ?x : {int}, ?y : {int}, source(video=yuv420p('a), 'b)) ->
source(video=yuv420p('a), 'b)

Composition:

This source inherits composition from its effective source.

Arguments:

• id (of type string?, which defaults to null)
• alpha (of type {float}, which defaults to 1.0)
• color (of type {int}, which defaults to 0)
• height (of type {int})
• width (of type {int})
• x (of type {int}, which defaults to 0)
• y (of type {int}, which defaults to 0)
• (unlabeled) (of type source(video=yuv420p('a), 'b))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source(video=yuv420p('a), 'b), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(video=yuv420p('a), 'b)?, replay_metadata : bool, starting : source(video=yuv420p('a), 'b) }) -> source(video=yuv420p('a), 'b)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

video.transparent

Deprecated: use video.alpha.of_color

Type:

(?id : string?, ?color : int, ?precision : float,
 source(video=yuv420p('a), 'b)) -> source(video=yuv420p('a), 'b)

Composition:

This source inherits composition from its effective source.

Arguments:

• id (of type string?, which defaults to null)
• color (of type int, which defaults to 0)
• precision (of type float, which defaults to 0.2)
• (unlabeled) (of type source(video=yuv420p('a), 'b))

Methods:

• buffered (of type () -> [string * float]): Length of buffered data.
• callbacks_count (of type () -> [string * int]): Callbacks a script has registered on this source, as pairs of callback name and count. A count that keeps growing is a function registering on a source it is handed without releasing what it registered.
• clear_last_metadata (of type () -> unit): Clear the last metadata from the source.
• clock (of type clock): The source's clock
• duration (of type () -> float): Estimation of the duration of the current track.
• elapsed (of type () -> float): Elapsed time in the current track.
• fallible (of type bool): Indicate if a source may fail, i.e. may not be ready to stream.
• generate_frame (of type () -> unit): Generate a frame from the source without consuming it. This can be useful in advanced cases where generating a frame is required to trigger some side effect like calculating some metadata before making a decision. You should make sure that the source is available before calling this function and it should only be called inside synchronous streaming loop callback such as on_frame!
• id (of type () -> string): Identifier of the source.
• insert_metadata (of type (?override : bool, ?new_track : bool, [string * string]) -> unit): Dynamically insert metadata in a stream. Inserts a new track with the given metadata if new_track is true. When override is false, metadata that the source provides itself takes precedence over the inserted one.
• is_active (of type () -> bool): true if the source is active, i.e. it is continuously animated by its own clock whenever it is ready. Typically, true for outputs and sources such as input.http.
• is_ready (of type () -> bool): Indicate if a source is ready to stream. This does not mean that the source is currently streaming, just that its resources are all properly initialized.
• is_up (of type () -> bool): Indicate that the source can be asked to produce some data at any time. This is true when the source is currently being used or if it could be used at any time, typically inside a switch or fallback.
• last_metadata (of type () -> [string * string]?): Return the last metadata from the source.
• log (of type {level : (() -> int).{exchange : (int) -> int, set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
• register_command (of type (?usage : string?, description : string, string, ((string) -> string)) -> unit): Register a server command for this source. Command is registered under the source's id namespace when it gets up and de-registered when it gets down.
• remaining (of type () -> float): Estimation of remaining time in the current track.
• reset_last_metadata_on_track (of type (() -> bool).{exchange : (bool) -> bool, set : (bool) -> unit}): If true, the source's last_metadata is reset on each new track. If a metadata is present along with the track mark, then it becomes the new last_metadata, otherwise, last_metadata becomes null`.
• seek (of type (float) -> float): Seek forward, in seconds (returns the amount of time effectively seeked).
• self_sync (of type () -> bool): Is the source currently controlling its own real-time loop.
• self_sync_description (of type () -> string)
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.

Callbacks:

• on_collect (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source is collected
• on_frame (of type (?before : bool, synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler on frame. When before is true, callback is executed before computing the frame and after otherwise
• on_frame_checksum (of type (?before : ((string?) -> unit)?, synchronous : bool, ((cache : string?, string) -> unit)) -> {release : () -> unit}): Call a given handler Register callbacks to compute frame checksums for debugging purposes. This is useful to track frame content changes through the streaming pipeline. The before callback is called before computing the frame with the checksum of the cached frame (if any, null otherwise). The main callback is called after computing the frame with the checksum of the generated frame and the remaining cache (if any).
• on_metadata (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler to execute on each metadata
• on_position (of type (position : {float}, ?remaining : bool, ?allow_partial : bool, synchronous : bool, ((float, [string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track position. If remaining is false, callback is executed when position in track is more or equal to position. If remaining is true, callback is executed when remaining time in the current track is less or equal to position. Keep in mind that elapsed time is exact while remaining time is always estimated. Remaining time is usually more accurate for file-based sources. When allow_partial is true, if the current track ends before the offset position is reached, callback is still executed
• on_shutdown (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called when source shuts down
• on_track (of type (synchronous : bool, (([string * string]) -> unit)) -> {release : () -> unit}): Call a given handler on track marks
• on_wake_up (of type (synchronous : bool, (() -> unit)) -> {release : () -> unit}): Call a given handler to be called after the source is asked to get ready

Composition methods:

• composition_type (of type (() -> string).{exchange : (string) -> string, set : (string) -> unit}): This source inherits composition from its effective source.
• on_leave (of type ({source : source(video=yuv420p('a), 'b), track_sensitive : bool}) -> unit): Called after switching away from this source in a switch operator, once the transition using the ending source has completed. Receives a record with source (the source being left) and track_sensitive (true if the ending source's last frame had a track mark, i.e. it finished naturally; false if it was preempted mid-track). This function must return quickly as it runs in the streaming thread. The default depends on the active composition profile: file sources (source.composition.file) skip the source when preempted mid-track so it starts fresh on its next selection, and do nothing when it finished naturally; live sources (source.composition.live) do nothing.
• on_select (of type ( { ending : source(video=yuv420p('a), 'b)?, replay_metadata : bool, starting : source(video=yuv420p('a), 'b) }) -> source(video=yuv420p('a), 'b)): Called when selecting this source in a switch operator. Receives a record with starting (the incoming source) and ending (the previous source, or null when the ending source reached a track boundary). Returns the source to use. By default, both file and live profiles fade out ending when non-null (up to 1 second). The default is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• replay_metadata (of type {bool}): Whether to replay the latest metadata on this source when it is selected in a switch operator. Defaults to true. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).
• single (of type bool): Forbid the selection of this source for two consecutive tracks in switch operators. Defaults to false.
• track_sensitive (of type {bool}): Whether this source insists on track boundaries in switch operators: when true, it prefers not to be interrupted mid-track and not to be started mid-track. A switch may only cut into a track that is still playing when at least one of the two sources involved has track_sensitive set to false; otherwise it waits for the playing source to reach a track boundary. File-based sources default to true; live network and hardware inputs default to false. The value is looked up at runtime from the active composition profile (source.composition.file or source.composition.live depending on composition_type).

which

Deprecated: this function has been replaced by file.which.

Type:

(string) -> string

Arguments:

• (unlabeled) (of type string)