Type

VideoEncodingAdditionalOptions

Additional options that control audio encoding.

type VideoEncodingAdditionalOptions = {
	alpha?: 'discard' | 'keep';
	bitrateMode?: 'constant' | 'variable';
	latencyMode?: 'quality' | 'realtime';
	fullCodecString?: string;
	hardwareAcceleration?: 'no-preference' | 'prefer-hardware' | 'prefer-software';
	scalabilityMode?: string;
	contentHint?: string;
};

Used by

• canEncodeVideo()
• VideoEncodingConfig

Properties

alpha

alpha?: 'discard' | 'keep';

What to do with alpha data contained in the video samples.

• 'discard' (default): Only the samples' color data is kept; the video is opaque.
• 'keep': The samples' alpha data is also encoded as side data. Make sure to pair this mode with a container format that supports transparency (such as WebM or Matroska).

bitrateMode

bitrateMode?: 'constant' | 'variable';

Configures the bitrate mode; defaults to 'variable'.

latencyMode

latencyMode?: 'quality' | 'realtime';

The latency mode used by the encoder; controls the performance-quality tradeoff.

• 'quality' (default): The encoder prioritizes quality over latency, and no frames can be dropped.
• 'realtime': The encoder prioritizes low latency over quality, and may drop frames if the encoder becomes overloaded to keep up with real-time requirements.

fullCodecString

fullCodecString?: string;

The full codec string as specified in the WebCodecs Codec Registry. This string must match the codec specified in codec. When not set, a fitting codec string will be constructed automatically by the library.

hardwareAcceleration

hardwareAcceleration?: 'no-preference' | 'prefer-hardware' | 'prefer-software';

A hint that configures the hardware acceleration method of this codec. This is best left on 'no-preference', the default.

scalabilityMode

scalabilityMode?: string;

An encoding scalability mode identifier as defined by WebRTC-SVC.

contentHint

contentHint?: string;

An encoding video content hint as defined by mst-content-hint.