Method decodeInternal

src/video_decoder.ts:275–316

(chunk: EncodedVideoChunk)

	}

	private async decodeInternal(chunk: EncodedVideoChunk) {
		const currentConfigId = this.currentConfigId;

		using lock = this.mutex.lock();
		await lock.ready; // Unconditional await here to queue a microtask

		if (this.currentConfigId !== currentConfigId) {
			return;
		}

		// Spec 4.5: Decrement [[decodeQueueSize]] and run the Schedule Dequeue Event algorithm.
		this.decrementQueue();

		assert(this.codecContext);

		const data = Buffer.from({ length: chunk.byteLength });
		chunk.copyTo(data);

		this.packet.isKeyframe = chunk.type === 'key';
		this.packet.data = data;
		this.packet.timeBase = { num: 1, den: 1e6 };
		this.packet.pts = BigInt(chunk.timestamp);
		this.packet.dts = AV_NOPTS_VALUE;
		this.packet.duration = BigInt(chunk.duration ?? 0);

		const ret = await this.codecContext.sendPacket(this.packet);

		if (ret < 0) {
			// Spec 4.5: If decoding results in an error, queue a task to run the Close VideoDecoder algorithm
			// with EncodingError
			throw new DOMException('Failed to send packet', 'EncodingError');
		}

		while (true) {
			const receiveRet = await this.codecContext.receiveFrame(this.frame);
			if (receiveRet < 0) {
				break;
			}

			this.outputFrame(currentConfigId);
		}
	}

	/**
	 * Flushes all pending decode operations and waits for completion.