src/demux/aacdemuxer.ts
- /**
- * AAC demuxer
- */
- import BaseAudioDemuxer from './base-audio-demuxer';
- import * as ADTS from './adts';
- import { logger } from '../utils/logger';
- import * as ID3 from '../demux/id3';
- import type { HlsEventEmitter } from '../events';
- import type { HlsConfig } from '../config';
-
- class AACDemuxer extends BaseAudioDemuxer {
- private readonly observer: HlsEventEmitter;
- private readonly config: HlsConfig;
- static readonly minProbeByteLength: number = 9;
-
- constructor(observer, config) {
- super();
- this.observer = observer;
- this.config = config;
- }
-
- resetInitSegment(audioCodec, videoCodec, duration) {
- super.resetInitSegment(audioCodec, videoCodec, duration);
- this._audioTrack = {
- container: 'audio/adts',
- type: 'audio',
- id: 0,
- pid: -1,
- sequenceNumber: 0,
- isAAC: true,
- samples: [],
- manifestCodec: audioCodec,
- duration: duration,
- inputTimeScale: 90000,
- dropped: 0,
- };
- }
-
- // Source for probe info - https://wiki.multimedia.cx/index.php?title=ADTS
- static probe(data): boolean {
- if (!data) {
- return false;
- }
-
- // Check for the ADTS sync word
- // Look for ADTS header | 1111 1111 | 1111 X00X | where X can be either 0 or 1
- // Layer bits (position 14 and 15) in header should be always 0 for ADTS
- // More info https://wiki.multimedia.cx/index.php?title=ADTS
- const id3Data = ID3.getID3Data(data, 0) || [];
- let offset = id3Data.length;
-
- for (let length = data.length; offset < length; offset++) {
- if (ADTS.probe(data, offset)) {
- logger.log('ADTS sync word found !');
- return true;
- }
- }
- return false;
- }
-
- canParse(data, offset) {
- return ADTS.canParse(data, offset);
- }
-
- appendFrame(track, data, offset) {
- ADTS.initTrackConfig(
- track,
- this.observer,
- data,
- offset,
- track.manifestCodec
- );
- return ADTS.appendFrame(
- track,
- data,
- offset,
- this.initPTS as number,
- this.frameIndex
- );
- }
- }
-
- export default AACDemuxer;