Class AudioDataPolyfill

src/audio_data.ts:39–348

 * Corresponds to the WebCodecs AudioData API.
 */
export class AudioDataPolyfill {
	/** @internal */
	_data: Uint8Array<ArrayBuffer> | Frame | null = null;
	private closed: boolean = false;

	/**
	 * The sample format, or null if closed.
	 */
	readonly format: AudioSampleFormat | null;
	/**
	 * The number of samples per second.
	 */
	readonly sampleRate: number;
	/**
	 * The number of audio frames (samples per channel).
	 */
	readonly numberOfFrames: number;
	/**
	 * The number of audio channels.
	 */
	readonly numberOfChannels: number;
	/**
	 * The timestamp in integer microseconds.
	 */
	readonly timestamp: number;
	/**
	 * The duration in integer microseconds.
	 */
	readonly duration: number;

	constructor(init: Frame);
	constructor(init: AudioDataInit);
	constructor(init: AudioDataInit | Frame) {
		if (init instanceof Frame) {
			const format = toAudioSampleFormat(init.format as AVSampleFormat);
			if (!format) {
				throw new TypeError('Unsupported audio sample format: ' + init.format);
			}

			this.format = format;
			this.sampleRate = init.sampleRate;
			this.numberOfFrames = init.nbSamples;
			this.numberOfChannels = init.channels;
			this.timestamp = Number(init.pts);
			this.duration = Number(init.duration);

			this._data = init;
		} else {
			if (!Number.isFinite(init.sampleRate) || init.sampleRate <= 0) {
				throw new TypeError('Invalid AudioDataInit: sampleRate must be > 0.');
			}
			if (!Number.isInteger(init.numberOfChannels) || init.numberOfChannels <= 0) {
				throw new TypeError('Invalid AudioDataInit: numberOfChannels must be an integer > 0.');
			}
			// Spec: numberOfFrames is required and must be > 0
			if (!Number.isInteger(init.numberOfFrames) || init.numberOfFrames <= 0) {
				throw new TypeError('Invalid AudioDataInit: numberOfFrames must be an integer > 0.');
			}