Make ADTS demuxer spit out ADTS packets instead of AAC, make ADTS muxer accept both AAC and ADTS input

test/browser/adts-demuxing.test.ts

@@ -0,0 +1,68 @@
+import { expect, test } from 'vitest';
+import { Input } from '../../src/input.js';
+import { UrlSource } from '../../src/source.js';
+import { ADTS, ALL_FORMATS } from '../../src/input-format.js';
+import { AudioSampleSink, EncodedPacketSink } from '../../src/media-sink.js';
+import { assert } from '../../src/misc.js';
+
+test('ADTS demuxing', async () => {
+	using input = new Input({
+		source: new UrlSource('/sample3.aac'),
+		formats: ALL_FORMATS,
+	});
+
+	expect(await input.getFormat()).toBe(ADTS);
+
+	const audioTrack = await input.getPrimaryAudioTrack();
+	assert(audioTrack);
+
+	expect(audioTrack.codec).toBe('aac');
+	expect(audioTrack.sampleRate).toBe(44100);
+	expect(audioTrack.numberOfChannels).toBe(2);
+
+	const decoderConfig = await audioTrack.getDecoderConfig();
+	assert(decoderConfig);
+
+	expect(decoderConfig).toEqual({
+		codec: 'mp4a.40.2',
+		sampleRate: 44100,
+		numberOfChannels: 2,
+		// No description
+	});
+
+	const sink = new EncodedPacketSink(audioTrack);
+
+	const firstPacket = await sink.getFirstPacket();
+	assert(firstPacket);
+
+	expect(firstPacket.data[0]).toBe(0xff);
+	expect((firstPacket.data[1]! & 0xf0)).toBe(0xf0); // Second nibble is also all 1s
+	expect(firstPacket.type).toBe('key');
+
+	const secondPacket = await sink.getNextPacket(firstPacket);
+	assert(secondPacket);
+
+	expect(secondPacket.data[0]).toBe(0xff);
+	expect((secondPacket.data[1]! & 0xf0)).toBe(0xf0);
+	expect(secondPacket.type).toBe('key');
+});
+
+test('ADTS packet decodability', async () => {
+	using input = new Input({
+		source: new UrlSource('/sample3.aac'),
+		formats: ALL_FORMATS,
+	});
+
+	const audioTrack = await input.getPrimaryAudioTrack();
+	assert(audioTrack);
+
+	const sink = new AudioSampleSink(audioTrack);
+
+	let count = 0;
+	// eslint-disable-next-line @typescript-eslint/no-unused-vars
+	for await (using sample of sink.samples()) {
+		count++;
+	}
+
+	expect(count).toBeGreaterThan(0);
+});