Add @mediabunny/ac3 extension package

2026-09-27 10:53:50 +02:00 · 2026-02-12 18:31:59 +01:00
parent e3aa7108f5
commit a97200f3f0
46 changed files with 2083 additions and 71 deletions
@@ -8,6 +8,12 @@ import { MpegTsOutputFormat } from '../../src/output-format.js';
 import { BufferTarget } from '../../src/target.js';
 import { Conversion } from '../../src/conversion.js';
 import { AC3_REGISTRATION_DESCRIPTOR, EAC3_REGISTRATION_DESCRIPTOR } from '../../src/codec-data.js';
+import { canEncode } from '../../src/encode.js';
+import { AudioSampleSink, EncodedPacketSink } from '../../src/media-sink.js';
+import { AudioSampleSource } from '../../src/media-source.js';
+import { Mp4OutputFormat } from '../../src/output-format.js';
+import { AudioSample } from '../../src/sample.js';
+import { registerAc3Decoder, registerAc3Encoder } from '@mediabunny/ac3';

 const __dirname = new URL('.', import.meta.url).pathname;

@@ -122,3 +128,200 @@ test('reads and writes E-AC-3 in MPEG-TS', async () => {
 	}
 	expect(found).toBe(true);
 });
+
+test('Custom coder registration', async () => {
+	using ac3Input = new Input({
+		source: new FilePathSource(path.join(__dirname, '..', 'public/ac3.mp4')),
+		formats: ALL_FORMATS,
+	});
+	using eac3Input = new Input({
+		source: new FilePathSource(path.join(__dirname, '..', 'public/eac3.mp4')),
+		formats: ALL_FORMATS,
+	});
+
+	const ac3Track = (await ac3Input.getPrimaryAudioTrack())!;
+	const eac3Track = (await eac3Input.getPrimaryAudioTrack())!;
+
+	// Before registration, nothing can decode or encode AC3/EAC3
+	expect(await ac3Track.canDecode()).toBe(false);
+	expect(await eac3Track.canDecode()).toBe(false);
+	expect(await canEncode('ac3')).toBe(false);
+	expect(await canEncode('eac3')).toBe(false);
+
+	registerAc3Decoder();
+	registerAc3Encoder();
+
+	// After registration, both should work
+	expect(await ac3Track.canDecode()).toBe(true);
+	expect(await eac3Track.canDecode()).toBe(true);
+	expect(await canEncode('ac3')).toBe(true);
+	expect(await canEncode('eac3')).toBe(true);
+});
+
+test('AC-3 decoding', async () => {
+	registerAc3Decoder();
+
+	using input = new Input({
+		source: new FilePathSource(path.join(__dirname, '..', 'public/ac3.mp4')),
+		formats: ALL_FORMATS,
+	});
+
+	const track = (await input.getPrimaryAudioTrack())!;
+	const { packetCount } = await track.computePacketStats();
+	const sink = new AudioSampleSink(track);
+
+	let sampleCount = 0;
+	let nextTimestamp = 0;
+
+	for await (using sample of sink.samples()) {
+		expect(sample.timestamp).toBeCloseTo(nextTimestamp);
+		expect(sample.duration).toBe(0.032);
+		expect(sample.format).toBe('f32-planar');
+		expect(sample.numberOfChannels).toBe(track.numberOfChannels);
+		expect(sample.sampleRate).toBe(track.sampleRate);
+
+		nextTimestamp += sample.duration;
+		sampleCount++;
+	}
+
+	expect(sampleCount).toBe(packetCount);
+});
+
+test('E-AC-3 decoding', async () => {
+	registerAc3Decoder();
+
+	using input = new Input({
+		source: new FilePathSource(path.join(__dirname, '..', 'public/eac3.mp4')),
+		formats: ALL_FORMATS,
+	});
+
+	const track = (await input.getPrimaryAudioTrack())!;
+	const { packetCount } = await track.computePacketStats();
+	const sink = new AudioSampleSink(track);
+
+	let sampleCount = 0;
+	let nextTimestamp = 0;
+
+	for await (using sample of sink.samples()) {
+		expect(sample.timestamp).toBeCloseTo(nextTimestamp);
+		expect(sample.duration).toBe(0.032);
+		expect(sample.format).toBe('f32-planar');
+		expect(sample.numberOfChannels).toBe(track.numberOfChannels);
+		expect(sample.sampleRate).toBe(track.sampleRate);
+
+		nextTimestamp += sample.duration;
+		sampleCount++;
+	}
+
+	expect(sampleCount).toBe(packetCount);
+});
+
+const createSineWave = (sampleRate: number, channels: number, durationSeconds: number) => {
+	const totalFrames = sampleRate * durationSeconds;
+	const data = new Float32Array(totalFrames * channels);
+
+	for (let i = 0; i < totalFrames; i++) {
+		const value = Math.sin(2 * Math.PI * 440 * i / sampleRate);
+		for (let ch = 0; ch < channels; ch++) {
+			data[i * channels + ch] = value;
+		}
+	}
+
+	return data;
+};
+
+test('AC-3 encoding', async () => {
+	registerAc3Encoder();
+
+	const sampleRate = 48000;
+	const channels = 2;
+	const durationSeconds = 2;
+	const data = createSineWave(sampleRate, channels, durationSeconds);
+
+	const output = new Output({
+		format: new Mp4OutputFormat(),
+		target: new BufferTarget(),
+	});
+
+	const audioSource = new AudioSampleSource({ codec: 'ac3', bitrate: 192000 });
+	output.addAudioTrack(audioSource);
+
+	await output.start();
+	await audioSource.add(new AudioSample({
+		data,
+		format: 'f32',
+		numberOfChannels: channels,
+		sampleRate,
+		timestamp: 0,
+	}));
+	audioSource.close();
+	await output.finalize();
+
+	using input = new Input({
+		source: new BufferSource(output.target.buffer!),
+		formats: ALL_FORMATS,
+	});
+
+	const track = (await input.getPrimaryAudioTrack())!;
+	expect(track.codec).toBe('ac3');
+	expect(track.sampleRate).toBe(sampleRate);
+	expect(track.numberOfChannels).toBe(channels);
+
+	const sink = new EncodedPacketSink(track);
+	let packetCount = 0;
+	for await (const packet of sink.packets()) {
+		expect(packet.type).toBe('key');
+		packetCount++;
+	}
+	expect(packetCount).toBeGreaterThan(0);
+
+	expect(await track.computeDuration()).toBeCloseTo(2, 1);
+});
+
+test('E-AC-3 encoding', async () => {
+	registerAc3Encoder();
+
+	const sampleRate = 48000;
+	const channels = 2;
+	const durationSeconds = 2;
+	const data = createSineWave(sampleRate, channels, durationSeconds);
+
+	const output = new Output({
+		format: new Mp4OutputFormat(),
+		target: new BufferTarget(),
+	});
+
+	const audioSource = new AudioSampleSource({ codec: 'eac3', bitrate: 192000 });
+	output.addAudioTrack(audioSource);
+
+	await output.start();
+	await audioSource.add(new AudioSample({
+		data,
+		format: 'f32',
+		numberOfChannels: channels,
+		sampleRate,
+		timestamp: 0,
+	}));
+	audioSource.close();
+	await output.finalize();
+
+	using input = new Input({
+		source: new BufferSource(output.target.buffer!),
+		formats: ALL_FORMATS,
+	});
+
+	const track = (await input.getPrimaryAudioTrack())!;
+	expect(track.codec).toBe('eac3');
+	expect(track.sampleRate).toBe(sampleRate);
+	expect(track.numberOfChannels).toBe(channels);
+
+	const sink = new EncodedPacketSink(track);
+	let packetCount = 0;
+	for await (const packet of sink.packets()) {
+		expect(packet.type).toBe('key');
+		packetCount++;
+	}
+	expect(packetCount).toBeGreaterThan(0);
+
+	expect(await track.computeDuration()).toBeCloseTo(2, 1);
+});