arcodange/mediabunny
1
0
Fork 0
mirror of https://github.com/arcodange-org/mediabunny.git synced 2026-10-03 13:53:53 +02:00
Code Issues Packages Projects Releases Wiki Activity

Add MPEG-TS muxer, fix a demuxer bug, remove Infinity from output format track counts

Browse Source
This commit is contained in:
Vanilagy
2026-01-16 16:33:28 +01:00
parent ae37973878
commit e8b27768a9
13 changed files with 1705 additions and 64 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/adts/adts-muxer.ts
+14 -31
View File
@@ -6,20 +6,20 @@
* file, You can obtain one at https://mozilla.org/MPL/2.0/.
*/
import { AacAudioSpecificConfig, parseAacAudioSpecificConfig, validateAudioChunkMetadata } from '../codec';
import { Bitstream, toUint8Array } from '../misc';
import { parseAacAudioSpecificConfig, validateAudioChunkMetadata } from '../codec';
import { assert, Bitstream, toUint8Array } from '../misc';
import { Muxer } from '../muxer';
import { Output, OutputAudioTrack } from '../output';
import { AdtsOutputFormat } from '../output-format';
import { EncodedPacket } from '../packet';
import { Writer } from '../writer';
import { buildAdtsHeaderTemplate, writeAdtsFrameLength } from './adts-misc';
export class AdtsMuxer extends Muxer {
private format: AdtsOutputFormat;
private writer: Writer;
private header = new Uint8Array(7);
private headerBitstream = new Bitstream(this.header);
private audioSpecificConfig: AacAudioSpecificConfig | null = null;
private header: Uint8Array | null = null;
private headerBitstream: Bitstream | null = null;
private inputIsAdts: boolean | null = null;
constructor(output: Output, format: AdtsOutputFormat) {
@@ -46,13 +46,12 @@ export class AdtsMuxer extends Muxer {
packet: EncodedPacket,
meta?: EncodedAudioChunkMetadata,
) {
// https://wiki.multimedia.cx/index.php/ADTS (last visited: 2025/08/17)
const release = await this.mutex.acquire();
try {
this.validateAndNormalizeTimestamp(track, packet.timestamp, packet.type === 'key');
// First packet - determine input format from metadata
if (this.inputIsAdts === null) {
validateAudioChunkMetadata(meta);
@@ -65,27 +64,10 @@ export class AdtsMuxer extends Muxer {
this.inputIsAdts = !description;
if (!this.inputIsAdts) {
this.audioSpecificConfig = parseAacAudioSpecificConfig(toUint8Array(description!));
const { objectType, frequencyIndex, channelConfiguration } = this.audioSpecificConfig;
const profile = objectType - 1;
this.headerBitstream.writeBits(12, 0b1111_11111111); // Syncword
this.headerBitstream.writeBits(1, 0); // MPEG Version
this.headerBitstream.writeBits(2, 0); // Layer
this.headerBitstream.writeBits(1, 1); // Protection absence
this.headerBitstream.writeBits(2, profile); // Profile
this.headerBitstream.writeBits(4, frequencyIndex); // MPEG-4 Sampling Frequency Index
this.headerBitstream.writeBits(1, 0); // Private bit
this.headerBitstream.writeBits(3, channelConfiguration); // MPEG-4 Channel Configuration
this.headerBitstream.writeBits(1, 0); // Originality
this.headerBitstream.writeBits(1, 0); // Home
this.headerBitstream.writeBits(1, 0); // Copyright ID bit
this.headerBitstream.writeBits(1, 0); // Copyright ID start
this.headerBitstream.skipBits(13); // Frame length
this.headerBitstream.writeBits(11, 0x7ff); // Buffer fullness
this.headerBitstream.writeBits(2, 0); // Number of AAC frames minus 1
// Omit CRC check
const config = parseAacAudioSpecificConfig(toUint8Array(description!));
const template = buildAdtsHeaderTemplate(config);
this.header = template.header;
this.headerBitstream = template.bitstream;
}
}
@@ -98,10 +80,11 @@ export class AdtsMuxer extends Muxer {
this.format._options.onFrame(packet.data, startPos);
}
} else {
// Packets are raw AAC, prepend ADTS header
assert(this.header);
// Packets are raw AAC, we gotta turn it into ADTS
const frameLength = packet.data.byteLength + this.header.byteLength;
this.headerBitstream.pos = 30;
this.headerBitstream.writeBits(13, frameLength);
writeAdtsFrameLength(this.headerBitstream!, frameLength);
const startPos = this.writer.getPos();
this.writer.write(this.header);