music-metadata
Version:
Music metadata parser for Node.js, supporting virtual any audio and tag format.
393 lines • 13.2 kB
JavaScript
import * as Token from 'token-types';
import initDebug from 'debug';
import { FourCcToken } from '../common/FourCC.js';
import { makeUnexpectedFileContentError } from '../ParseError.js';
const debug = initDebug('music-metadata:parser:MP4:atom');
export class Mp4ContentError extends makeUnexpectedFileContentError('MP4') {
}
export const Header = {
len: 8,
get: (buf, off) => {
const length = Token.UINT32_BE.get(buf, off);
if (length < 0)
throw new Mp4ContentError('Invalid atom header length');
return {
length: BigInt(length),
name: new Token.StringType(4, 'latin1').get(buf, off + 4)
};
},
put: (buf, off, hdr) => {
Token.UINT32_BE.put(buf, off, Number(hdr.length));
return FourCcToken.put(buf, off + 4, hdr.name);
}
};
/**
* Ref: https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap1/qtff1.html#//apple_ref/doc/uid/TP40000939-CH203-38190
*/
export const ExtendedSize = Token.UINT64_BE;
export const ftyp = {
len: 4,
get: (buf, off) => {
return {
type: new Token.StringType(4, 'ascii').get(buf, off)
};
}
};
export const tkhd = {
len: 4,
get: (buf, off) => {
return {
type: new Token.StringType(4, 'ascii').get(buf, off)
};
}
};
/**
* Token: Movie Header Atom
*/
export const mhdr = {
len: 8,
get: (buf, off) => {
return {
version: Token.UINT8.get(buf, off),
flags: Token.UINT24_BE.get(buf, off + 1),
nextItemID: Token.UINT32_BE.get(buf, off + 4)
};
}
};
/**
* Base class for 'fixed' length atoms.
* In some cases these atoms are longer then the sum of the described fields.
* Issue: https://github.com/Borewit/music-metadata/issues/120
*/
export class FixedLengthAtom {
/**
*
* @param {number} len Length as specified in the size field
* @param {number} expLen Total length of sum of specified fields in the standard
* @param atomId Atom ID
*/
constructor(len, expLen, atomId) {
if (len < expLen) {
throw new Mp4ContentError(`Atom ${atomId} expected to be ${expLen}, but specifies ${len} bytes long.`);
}
if (len > expLen) {
debug(`Warning: atom ${atomId} expected to be ${expLen}, but was actually ${len} bytes long.`);
}
this.len = len;
}
}
/**
* Timestamp stored in seconds since Mac Epoch (1 January 1904)
*/
const SecondsSinceMacEpoch = {
len: 4,
get: (buf, off) => {
const secondsSinceUnixEpoch = Token.UINT32_BE.get(buf, off) - 2082844800;
return new Date(secondsSinceUnixEpoch * 1000);
}
};
/**
* Token: Media Header Atom
* Ref:
* - https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html#//apple_ref/doc/uid/TP40000939-CH204-SW34
* - https://wiki.multimedia.cx/index.php/QuickTime_container#mdhd
*/
export class MdhdAtom extends FixedLengthAtom {
constructor(len) {
super(len, 24, 'mdhd');
}
get(buf, off) {
return {
version: Token.UINT8.get(buf, off + 0),
flags: Token.UINT24_BE.get(buf, off + 1),
creationTime: SecondsSinceMacEpoch.get(buf, off + 4),
modificationTime: SecondsSinceMacEpoch.get(buf, off + 8),
timeScale: Token.UINT32_BE.get(buf, off + 12),
duration: Token.UINT32_BE.get(buf, off + 16),
language: Token.UINT16_BE.get(buf, off + 20),
quality: Token.UINT16_BE.get(buf, off + 22)
};
}
}
/**
* Token: Movie Header Atom
*/
export class MvhdAtom extends FixedLengthAtom {
constructor(len) {
super(len, 100, 'mvhd');
}
get(buf, off) {
return {
version: Token.UINT8.get(buf, off),
flags: Token.UINT24_BE.get(buf, off + 1),
creationTime: SecondsSinceMacEpoch.get(buf, off + 4),
modificationTime: SecondsSinceMacEpoch.get(buf, off + 8),
timeScale: Token.UINT32_BE.get(buf, off + 12),
duration: Token.UINT32_BE.get(buf, off + 16),
preferredRate: Token.UINT32_BE.get(buf, off + 20),
preferredVolume: Token.UINT16_BE.get(buf, off + 24),
// ignore reserver: 10 bytes
// ignore matrix structure: 36 bytes
previewTime: Token.UINT32_BE.get(buf, off + 72),
previewDuration: Token.UINT32_BE.get(buf, off + 76),
posterTime: Token.UINT32_BE.get(buf, off + 80),
selectionTime: Token.UINT32_BE.get(buf, off + 84),
selectionDuration: Token.UINT32_BE.get(buf, off + 88),
currentTime: Token.UINT32_BE.get(buf, off + 92),
nextTrackID: Token.UINT32_BE.get(buf, off + 96)
};
}
}
/**
* Data Atom Structure
*/
export class DataAtom {
constructor(len) {
this.len = len;
}
get(buf, off) {
return {
type: {
set: Token.UINT8.get(buf, off + 0),
type: Token.UINT24_BE.get(buf, off + 1)
},
locale: Token.UINT24_BE.get(buf, off + 4),
value: new Token.Uint8ArrayType(this.len - 8).get(buf, off + 8)
};
}
}
/**
* Data Atom Structure
* Ref: https://developer.apple.com/library/content/documentation/QuickTime/QTFF/Metadata/Metadata.html#//apple_ref/doc/uid/TP40000939-CH1-SW31
*/
export class NameAtom {
constructor(len) {
this.len = len;
}
get(buf, off) {
return {
version: Token.UINT8.get(buf, off),
flags: Token.UINT24_BE.get(buf, off + 1),
name: new Token.StringType(this.len - 4, 'utf-8').get(buf, off + 4)
};
}
}
/**
* Track Header Atoms structure
* Ref: https://developer.apple.com/library/content/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html#//apple_ref/doc/uid/TP40000939-CH204-25550
*/
export class TrackHeaderAtom {
constructor(len) {
this.len = len;
}
get(buf, off) {
return {
version: Token.UINT8.get(buf, off),
flags: Token.UINT24_BE.get(buf, off + 1),
creationTime: SecondsSinceMacEpoch.get(buf, off + 4),
modificationTime: SecondsSinceMacEpoch.get(buf, off + 8),
trackId: Token.UINT32_BE.get(buf, off + 12),
// reserved 4 bytes
duration: Token.UINT32_BE.get(buf, off + 20),
layer: Token.UINT16_BE.get(buf, off + 24),
alternateGroup: Token.UINT16_BE.get(buf, off + 26),
volume: Token.UINT16_BE.get(buf, off + 28) // ToDo: fixed point
// ToDo: add remaining fields
};
}
}
/**
* Atom: Sample Description Atom ('stsd')
* Ref: https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html#//apple_ref/doc/uid/TP40000939-CH204-25691
*/
const stsdHeader = {
len: 8,
get: (buf, off) => {
return {
version: Token.UINT8.get(buf, off),
flags: Token.UINT24_BE.get(buf, off + 1),
numberOfEntries: Token.UINT32_BE.get(buf, off + 4)
};
}
};
/**
* Atom: Sample Description Atom ('stsd')
* Ref: https://developer.apple.com/documentation/quicktime-file-format/sample_description_atom
*/
class SampleDescriptionTable {
constructor(len) {
this.len = len;
}
get(buf, off) {
const descrLen = this.len - 12;
return {
dataFormat: FourCcToken.get(buf, off),
dataReferenceIndex: Token.UINT16_BE.get(buf, off + 10),
description: descrLen > 0 ? new Token.Uint8ArrayType(descrLen).get(buf, off + 12) : undefined
};
}
}
/**
* Atom: Sample-description Atom ('stsd')
* Ref: https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html#//apple_ref/doc/uid/TP40000939-CH204-25691
*/
export class StsdAtom {
constructor(len) {
this.len = len;
}
get(buf, off) {
const header = stsdHeader.get(buf, off);
off += stsdHeader.len;
const table = [];
for (let n = 0; n < header.numberOfEntries; ++n) {
const size = Token.UINT32_BE.get(buf, off); // Sample description size
off += Token.UINT32_BE.len;
table.push(new SampleDescriptionTable(size - Token.UINT32_BE.len).get(buf, off));
off += size;
}
return {
header,
table
};
}
}
/**
* Common Sound Sample Description (version & revision)
* Ref: https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap3/qtff3.html#//apple_ref/doc/uid/TP40000939-CH205-57317
*/
export const SoundSampleDescriptionVersion = {
len: 8,
get(buf, off) {
return {
version: Token.INT16_BE.get(buf, off),
revision: Token.INT16_BE.get(buf, off + 2),
vendor: Token.INT32_BE.get(buf, off + 4)
};
}
};
/**
* Sound Sample Description (Version 0)
* Ref: https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap3/qtff3.html#//apple_ref/doc/uid/TP40000939-CH205-130736
*/
export const SoundSampleDescriptionV0 = {
len: 12,
get(buf, off) {
return {
numAudioChannels: Token.INT16_BE.get(buf, off + 0),
sampleSize: Token.INT16_BE.get(buf, off + 2),
compressionId: Token.INT16_BE.get(buf, off + 4),
packetSize: Token.INT16_BE.get(buf, off + 6),
sampleRate: Token.UINT16_BE.get(buf, off + 8) + Token.UINT16_BE.get(buf, off + 10) / 10000
};
}
};
class SimpleTableAtom {
constructor(len, token) {
this.len = len;
this.token = token;
}
get(buf, off) {
const nrOfEntries = Token.INT32_BE.get(buf, off + 4);
return {
version: Token.INT8.get(buf, off + 0),
flags: Token.INT24_BE.get(buf, off + 1),
numberOfEntries: nrOfEntries,
entries: readTokenTable(buf, this.token, off + 8, this.len - 8, nrOfEntries)
};
}
}
export const TimeToSampleToken = {
len: 8,
get(buf, off) {
return {
count: Token.INT32_BE.get(buf, off + 0),
duration: Token.INT32_BE.get(buf, off + 4)
};
}
};
/**
* Time-to-sample('stts') atom.
* Store duration information for a media’s samples.
* Ref: https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html#//apple_ref/doc/uid/TP40000939-CH204-25696
*/
export class SttsAtom extends SimpleTableAtom {
constructor(len) {
super(len, TimeToSampleToken);
}
}
export const SampleToChunkToken = {
len: 12,
get(buf, off) {
return {
firstChunk: Token.INT32_BE.get(buf, off),
samplesPerChunk: Token.INT32_BE.get(buf, off + 4),
sampleDescriptionId: Token.INT32_BE.get(buf, off + 8)
};
}
};
/**
* Sample-to-Chunk ('stsc') atom interface
* Ref: https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html#//apple_ref/doc/uid/TP40000939-CH204-25706
*/
export class StscAtom extends SimpleTableAtom {
constructor(len) {
super(len, SampleToChunkToken);
}
}
/**
* Sample-size ('stsz') atom
* Ref: https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html#//apple_ref/doc/uid/TP40000939-CH204-25710
*/
export class StszAtom {
constructor(len) {
this.len = len;
}
get(buf, off) {
const nrOfEntries = Token.INT32_BE.get(buf, off + 8);
return {
version: Token.INT8.get(buf, off),
flags: Token.INT24_BE.get(buf, off + 1),
sampleSize: Token.INT32_BE.get(buf, off + 4),
numberOfEntries: nrOfEntries,
entries: readTokenTable(buf, Token.INT32_BE, off + 12, this.len - 12, nrOfEntries)
};
}
}
/**
* Chunk offset atom, 'stco'
* Ref: https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html#//apple_ref/doc/uid/TP40000939-CH204-25715
*/
export class StcoAtom extends SimpleTableAtom {
constructor(len) {
super(len, Token.INT32_BE);
this.len = len;
}
}
/**
* Token used to decode text-track from 'mdat' atom (raw data stream)
*/
export class ChapterText {
constructor(len) {
this.len = len;
}
get(buf, off) {
const titleLen = Token.INT16_BE.get(buf, off + 0);
const str = new Token.StringType(titleLen, 'utf-8');
return str.get(buf, off + 2);
}
}
function readTokenTable(buf, token, off, remainingLen, numberOfEntries) {
debug(`remainingLen=${remainingLen}, numberOfEntries=${numberOfEntries} * token-len=${token.len}`);
if (remainingLen === 0)
return [];
if (remainingLen !== numberOfEntries * token.len)
throw new Mp4ContentError('mismatch number-of-entries with remaining atom-length');
const entries = [];
// parse offset-table
for (let n = 0; n < numberOfEntries; ++n) {
entries.push(token.get(buf, off));
off += token.len;
}
return entries;
}
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