Class

Output

Main class orchestrating the creation of a new media file.

Used by

• Conversion.output
• ConversionOptions.output

Type parameters

Output<
	F extends OutputFormat = OutputFormat,
	T extends Target = Target,
>

See OutputFormat and Target.

Constructor

constructor(
	options: OutputOptions<F, T>,
): Output;

Creates a new instance of Output which can then be used to create a new media file according to the specified OutputOptions.

Properties

format

format: F;

The format of the output file.

state

state: 'pending' | 'started' | 'canceled' | 'finalizing' | 'finalized';

The current state of the output.

target

target: T;

The target to which the file will be written.

Methods

addVideoTrack()

addVideoTrack(
	source: VideoSource,
	metadata: VideoTrackMetadata = {},
): void;

Adds a video track to the output with the given source. Must be called before output is started.

See VideoSource and VideoTrackMetadata.

addAudioTrack()

addAudioTrack(
	source: AudioSource,
	metadata: AudioTrackMetadata = {},
): void;

Adds an audio track to the output with the given source. Must be called before output is started.

See AudioSource and AudioTrackMetadata.

addSubtitleTrack()

addSubtitleTrack(
	source: SubtitleSource,
	metadata: SubtitleTrackMetadata = {},
): void;

Adds a subtitle track to the output with the given source. Must be called before output is started.

See SubtitleSource and SubtitleTrackMetadata.

setMetadataTags()

setMetadataTags(
	tags: MetadataTags,
): void;

Sets descriptive metadata tags about the media file, such as title, author, date, or cover art. When called multiple times, only the metadata from the last call will be used.

Must be called before output is started.

See MetadataTags.

start()

start(): Promise<void>;

Starts the creation of the output file. This method should be called after all tracks have been added. Only after the output has started can media samples be added to the tracks.

Returns: A promise that resolves when the output has successfully started and is ready to receive media samples.

getMimeType()

getMimeType(): Promise<string>;

Resolves with the full MIME type of the output file, including track codecs.

The returned promise will resolve only once the precise codec strings of all tracks are known.

cancel()

cancel(): Promise<void>;

Cancels the creation of the output file, releasing internal resources like encoders and preventing further samples from being added.

Returns: A promise that resolves once all internal resources have been released.

finalize()

finalize(): Promise<void>;

Finalizes the output file. This method must be called after all media samples across all tracks have been added. Once the Promise returned by this method completes, the output file is ready.