src/demux/mp3demuxer.ts
- /**
- * MP3 demuxer
- */
- import BaseAudioDemuxer from './base-audio-demuxer';
- import * as ID3 from '../demux/id3';
- import { logger } from '../utils/logger';
- import * as MpegAudio from './mpegaudio';
-
- class MP3Demuxer extends BaseAudioDemuxer {
- resetInitSegment(
- initSegment: Uint8Array | undefined,
- audioCodec: string | undefined,
- videoCodec: string | undefined,
- trackDuration: number
- ) {
- super.resetInitSegment(initSegment, audioCodec, videoCodec, trackDuration);
- this._audioTrack = {
- container: 'audio/mpeg',
- type: 'audio',
- id: 2,
- pid: -1,
- sequenceNumber: 0,
- segmentCodec: 'mp3',
- samples: [],
- manifestCodec: audioCodec,
- duration: trackDuration,
- inputTimeScale: 90000,
- dropped: 0,
- };
- }
-
- static probe(data): boolean {
- if (!data) {
- return false;
- }
-
- // check if data contains ID3 timestamp and MPEG sync word
- // Look for MPEG header | 1111 1111 | 111X XYZX | where X can be either 0 or 1 and Y or Z should be 1
- // Layer bits (position 14 and 15) in header should be always different from 0 (Layer I or Layer II or Layer III)
- // More info http://www.mp3-tech.org/programmer/frame_header.html
- const id3Data = ID3.getID3Data(data, 0) || [];
- let offset = id3Data.length;
-
- for (let length = data.length; offset < length; offset++) {
- if (MpegAudio.probe(data, offset)) {
- logger.log('MPEG Audio sync word found !');
- return true;
- }
- }
- return false;
- }
-
- canParse(data, offset) {
- return MpegAudio.canParse(data, offset);
- }
-
- appendFrame(track, data, offset) {
- if (this.basePTS === null) {
- return;
- }
- return MpegAudio.appendFrame(
- track,
- data,
- offset,
- this.basePTS,
- this.frameIndex
- );
- }
- }
-
- export default MP3Demuxer;