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Version: 2.2.5

Source / Audio processing

accelerate​

Accelerate a stream by dropping frames. This is useful for testing scripts.

Type:

(?id : string?, ?randomize : {float}, ?ratio : {float}, source('a)) ->
source('a)

Arguments:

  • id (of type string?, which defaults to null): Force the value of the source ID.
  • randomize (of type {float}, which defaults to 1.): Randomization (0 means no randomization).
  • ratio (of type {float}, which defaults to 2.): A value higher than 1 means speeding up.
  • (unlabeled) (of type source('a))

Methods:

  • buffered (of type () -> [string * float]): Length of buffered data.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

This function is experimental.

bass_boost​

Add some bass to the sound.

Type:

(?frequency : {float}, ?gain : {float}, source(audio=pcm('a), 'b)) ->
source(audio=pcm('a), 'b)
where
  'b is a set of tracks to be muxed into a source and a set of internal tracks

Arguments:

  • frequency (of type {float}, which defaults to 200.): Frequency below which sound is considered as bass.
  • gain (of type {float}, which defaults to 10.): Amount of boosting (dB).
  • (unlabeled) (of type source(audio=pcm('a), 'b) where 'b is a set of tracks to be muxed into a source and a set of internal tracks): Source whose bass should be boosted

Methods:

  • buffered (of type () -> [string * float]): Length of buffered data.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

comb​

Comb filter

Type:

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

Arguments:

  • id (of type string?, which defaults to "comb"): Force the value of the track ID.
  • delay (of type float, which defaults to 0.001): Delay in seconds.
  • feedback (of type {float}, which defaults to -6.): Feedback coefficient in dB.
  • (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.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

compand​

Compand the signal.

Type:

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

Arguments:

  • id (of type string?, which defaults to "compand"): Force the value of the track ID.
  • mu (of type float, which defaults to 1.)
  • (unlabeled) (of type source(audio=source(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.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

compress​

Compress the signal.

Type:

(?id : string?, ?attack : {float}, ?release : {float}, ?lookahead : {float},
 ?threshold : {float}, ?track_sensitive : bool, ?knee : {float},
 ?pre_gain : {float}, ?gain : {float}, ?ratio : {float}, ?window : {float},
 ?wet : {float}, 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

Arguments:

  • id (of type string?, which defaults to null): Force the value of the track ID.
  • attack (of type {float}, which defaults to 50.): Attack time (ms).
  • release (of type {float}, which defaults to 400.): Release time (ms).
  • lookahead (of type {float}, which defaults to 0.): Lookahead (ms).
  • threshold (of type {float}, which defaults to -10.): Threshold level (dB).
  • track_sensitive (of type bool, which defaults to false): Reset on every track.
  • knee (of type {float}, which defaults to 1.): Knee width (dB).
  • pre_gain (of type {float}, which defaults to 0.): Pre-amplification (dB).
  • gain (of type {float}, which defaults to 0.): Post-amplification (dB).
  • ratio (of type {float}, which defaults to 2.): Gain reduction ratio (reduction is ratio:1). Must be at least 1.
  • window (of type {float}, which defaults to 0.): RMS window length (second). 0. means peak mode.
  • wet (of type {float}, which defaults to 1.): How much of input sound to output (between 0 and 1, 0 means only original sound, 1 means only compressed sound).
  • (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.
  • 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):
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

compress.exponential​

Exponential compressor.

Type:

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

Arguments:

  • id (of type string?, which defaults to null): Force the value of the track ID.
  • mu (of type float, which defaults to 2.): Exponential compression factor, typically greater than 1.
  • (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.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

compress.multiband​

Multiband compression. The list in argument specifies

  • the frequency below which we should apply compression (it is above previous band)
  • the attack time (ms)
  • the release time (ms)
  • the compression ratio
  • the threshold for compression
  • the gain for the band

Type:

(?limit : bool, ?wet : {float}, source(audio=pcm('a), 'b),
 [
  {
    attack : {float},
    frequency : {float},
    gain : {float},
    ratio : {float},
    release : {float},
    threshold : {float}
  }]) -> source(audio=pcm('a).{gain? : never, rms? : never}, 'b)
where
  'b is a set of tracks to be muxed into a source and a set of internal tracks

Arguments:

  • limit (of type bool, which defaults to true): Also apply limiting to bands.
  • wet (of type {float}, which defaults to 1.)
  • (unlabeled) (of type source(audio=pcm('a), 'b) where 'b is a set of tracks to be muxed into a source and a set of internal tracks): Parameters for compression bands.
  • (unlabeled) (of type [ { attack : {float}, frequency : {float}, gain : {float}, ratio : {float}, release : {float}, threshold : {float} }]): Source on which multiband compression should be applied.

Methods:

  • buffered (of type () -> [string * float]): Length of buffered data.
  • 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):
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

dry_wet​

Mix between dry and wet sources. Useful for testing effects. Typically:

c = interactive.float("wetness", min=0., max=1., 1.)
s = dry_wet(c, s, effect(s))

and vary c to hear the difference between the source without and with the effect.

Type:

(?power : bool, {float}, source('a), source('a)) -> source('a)
where 'a is a set of internal tracks

Arguments:

  • power (of type bool, which defaults to false): If true use constant power mixing.
  • (unlabeled) (of type {float}): Wetness coefficient, from 0 (fully dry) to 1 (fully wet).
  • (unlabeled) (of type source('a) where 'a is a set of internal tracks): Dry source.
  • (unlabeled) (of type source('a) where 'a is a set of internal tracks): Wet source.

Methods:

  • buffered (of type () -> [string * float]): Length of buffered data.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

filter.iir.eq.low_high​

A bandpass filter obtained by chaining a low-pass and a high-pass filter.

Type:

(?id : string?, low : {float}, high : {float}, ?q : float, source('a)) ->
source('a)

Arguments:

  • id (of type string?, which defaults to null)
  • low (of type {float}): Lower frequency of the bandpass filter.
  • high (of type {float}): Higher frequency of the bandpass filter.
  • q (of type float, which defaults to 1.): Q factor.
  • (unlabeled) (of type source('a)): Force the value of the source ID.

Methods:

  • buffered (of type () -> [string * float]): Length of buffered data.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

helium​

Increases the pitch, making voices sound like on helium.

Type:

(source(audio=pcm('a), 'b)) -> source(audio=pcm('a), 'b)

Arguments:

  • (unlabeled) (of type source(audio=pcm('a), 'b)): The input source.

Methods:

  • buffered (of type () -> [string * float]): Length of buffered data.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

limit​

A limiter. This is a compress with tweaked parameters.

Type:

(?id : string?, ?attack : {float}, ?release : {float}, ?ratio : {float},
 ?threshold : {float}, ?pre_gain : {float}, ?gain : {float},
 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

Arguments:

  • id (of type string?, which defaults to null)
  • attack (of type {float}, which defaults to 50.)
  • release (of type {float}, which defaults to 200.)
  • ratio (of type {float}, which defaults to 20.)
  • threshold (of type {float}, which defaults to -2.)
  • pre_gain (of type {float}, which defaults to 0.)
  • gain (of type {float}, which defaults to 0.)
  • (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.
  • 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):
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

mic_filter​

Remove low frequencies often produced by microphones.

Type:

(?frequency : float, source(audio=pcm('a), 'b)) -> source(audio=pcm('a), 'b)

Arguments:

  • frequency (of type float, which defaults to 200.): Frequency under which sound should be lowered.
  • (unlabeled) (of type source(audio=pcm('a), 'b)): The input source.

Methods:

  • buffered (of type () -> [string * float]): Length of buffered data.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

mix​

Mixing table controllable via source methods and optional server/telnet commands.

Type:

(?id : string?, ?namespace : string?, ?register_server_commands : bool,
 [source(audio=pcm('a), 'b).{id? : string}]) -> source(audio=pcm('a), 'b)
where
  'b is a set of tracks to be muxed into a source and a set of internal tracks

Arguments:

  • id (of type string?, which defaults to null): Force the value of the source ID.
  • namespace (of type string?, which defaults to null): Namespace for the source commands. Uses source ID when null.
  • register_server_commands (of type bool, which defaults to true): Register corresponding server commands
  • (unlabeled) (of type [source(audio=pcm('a), 'b).{id? : string}] where 'b is a set of tracks to be muxed into a source and a set of internal tracks)

Methods:

  • buffered (of type () -> [string * float]): Length of buffered data.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • inputs (of type [ { id : string, selected : (() -> bool) .{set : (bool) -> unit }, single : (() -> bool) .{set : (bool) -> unit }, source : source(audio=pcm('B), 'A) .{id? : string }, volume : (() -> float) .{set : (float) -> unit } }] where 'A is a set of tracks to be muxed into a source and a set of internal tracks):
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

nrj​

Compress and normalize, producing a more uniform and "full" sound.

Type:

(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

Arguments:

  • (unlabeled) (of type source(audio=pcm('a), 'b) where 'b is a set of tracks to be muxed into a source): The input source.

Methods:

  • buffered (of type () -> [string * float]): Length of buffered data.
  • 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):
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.

sky​

Multiband-compression.

Type:

(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 and a set of internal tracks

Arguments:

  • (unlabeled) (of type source(audio=pcm('a), 'b) where 'b is a set of tracks to be muxed into a source and a set of internal tracks): The input source.

Methods:

  • buffered (of type () -> [string * float]): Length of buffered data.
  • 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.
  • id (of type () -> string): Identifier of the source.
  • 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?).{set : (int) -> unit}}): Get or set the source's log level, from 1 to 5.
  • on_metadata (of type ((([string * string]) -> unit)) -> unit): Call a given handler on metadata packets.
  • on_shutdown (of type ((() -> unit)) -> unit): Register a function to be called when source shuts down.
  • on_track (of type ((([string * string]) -> unit)) -> unit): Call a given handler on new tracks.
  • on_wake_up (of type ((() -> unit)) -> unit): Register a function to be called after the source is asked to get ready. This is when, for instance, the source's final ID is set.
  • remaining (of type () -> float): Estimation of remaining time in the current track.
  • 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.
  • skip (of type () -> unit): Skip to the next track.
  • time (of type () -> float): Get a source's time, based on its assigned clock.