Track / Video processing

video.add_cover

Extract cover from the source's metadata and add it as a static image.

Type:

(?fallible : bool, ?width : {int}?, ?height : {int}?, ?x : {int}, ?y : {int},
 ?mime_types : [string * string], default : string, source(video=canvas('a),
 'b)) -> source(video=canvas('a), 'b)
where 'b is a set of tracks to be muxed into a source

Arguments:

• fallible (of type bool, which defaults to false): Whether we are allowed to fail (in case the file is non-existent or invalid).
• width (of type {int}?, which defaults to null): Scale to width
• height (of type {int}?, which defaults to null): Scale to height
• x (of type {int}, which defaults to 0): x position.
• y (of type {int}, which defaults to 0): y position.
• mime_types (of type [string * string], which defaults to [("image/gif", "gif"), ("image/jpg", "jpeg"), ("image/jpeg", "jpeg"), ("image/png", "png"), ("image/webp", "webp")]): Recognized mime types and their corresponding file extensions.
• default (of type string): Default cover file when no cover is available
• (unlabeled) (of type source(video=canvas('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.
• 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.
• 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.
• 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).{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.
• skip (of type () -> unit): Skip to the next track.
• time (of type () -> float): Get a source's time, based on its assigned clock.