mp4frag
Version:
A parser that reads piped data from ffmpeg containing a fragmented mp4 and splits it into an initialization segment and media segments. Designed for streaming live video relayed from cctv cameras.
1,138 lines (1,074 loc) • 38.2 kB
JavaScript
'use strict';
const BufferPool = require('./lib/buffer-pool');
const { Transform } = require('stream');
/*
todo after version 0.7.0
const { deprecate } = require('util');
*/
/**
* @file
* <ul>
* <li>Creates a stream transform for piping a fmp4 (fragmented mp4) from ffmpeg.</li>
* <li>Can be used to generate a fmp4 m3u8 HLS playlist and compatible file fragments.</li>
* <li>Can be used for storing past segments of the mp4 video in a buffer for later access.</li>
* <li>Must use the following ffmpeg args <b><i>-movflags +frag_keyframe+empty_moov+default_base_moof</i></b> to generate
* a valid fmp4 with a compatible file structure : ftyp+moov -> moof+mdat -> moof+mdat ...</li>
* </ul>
* @extends stream.Transform
*/
class Mp4Frag extends Transform {
/* ----> static private fields <---- */
static #ERR = { invalidArg: 'ERR_INVALID_ARG', chunkParse: 'ERR_CHUNK_PARSE', chunkLength: 'ERR_CHUNK_LENGTH' };
static #HLS_INIT_DEF = true; // initialize hls playlist before 1st segment
static #HLS_SIZE = { def: 4, min: 2, max: 20 }; // hls playlist size
static #HLS_EXTRA = { def: 0, min: 0, max: 10 }; // hls playlist extra segments in memory
static #SEG_SIZE = { def: 2, min: 2, max: 30 }; // segment list size
static #FTYP = Mp4Frag.#boxFrom([0x66, 0x74, 0x79, 0x70]); // ftyp
static #MOOV = Mp4Frag.#boxFrom([0x6d, 0x6f, 0x6f, 0x76]); // moov
static #MDHD = Mp4Frag.#boxFrom([0x6d, 0x64, 0x68, 0x64]); // mdhd
static #MOOF = Mp4Frag.#boxFrom([0x6d, 0x6f, 0x6f, 0x66]); // moof
static #MDAT = Mp4Frag.#boxFrom([0x6d, 0x64, 0x61, 0x74]); // mdat
static #TFHD = Mp4Frag.#boxFrom([0x74, 0x66, 0x68, 0x64]); // tfhd
static #TRUN = Mp4Frag.#boxFrom([0x74, 0x72, 0x75, 0x6e]); // trun
static #MFRA = Mp4Frag.#boxFrom([0x6d, 0x66, 0x72, 0x61]); // mfra
static #HVCC = Mp4Frag.#boxFrom([0x68, 0x76, 0x63, 0x43]); // hvcC
static #HEV1 = Mp4Frag.#boxFrom([0x68, 0x65, 0x76, 0x31]); // hev1
static #HVC1 = Mp4Frag.#boxFrom([0x68, 0x76, 0x63, 0x31]); // hvc1
static #AVCC = Mp4Frag.#boxFrom([0x61, 0x76, 0x63, 0x43]); // avcC
static #AVC1 = Mp4Frag.#boxFrom([0x61, 0x76, 0x63, 0x31]); // avc1
static #AVC2 = Mp4Frag.#boxFrom([0x61, 0x76, 0x63, 0x32]); // avc2
static #AVC3 = Mp4Frag.#boxFrom([0x61, 0x76, 0x63, 0x33]); // avc3
static #AVC4 = Mp4Frag.#boxFrom([0x61, 0x76, 0x63, 0x34]); // avc4
static #MP4A = Mp4Frag.#boxFrom([0x6d, 0x70, 0x34, 0x61]); // mp4a
static #ESDS = Mp4Frag.#boxFrom([0x65, 0x73, 0x64, 0x73]); // esds
/* ----> private method placeholders <---- */
#bufferConcat = Buffer.concat; // will be reassigned if setting pool > 0
#parseChunk = this.#noop; // reassigned after each box parsing is complete
#setKeyframe = this.#noop; // placeholder for #setKeyframeAVCC() | #setKeyframeHECC()
#sendInit = this.#sendInitAsBuffer; // will be reassigned if setting readableObjectMode to true
#sendSegment = this.#sendSegmentAsBuffer; // will be reassigned if setting readableObjectMode to true
/* ----> private fields <---- */
#hlsPlaylist = undefined;
#segmentCount = 0;
#bufferPool = 0;
#poolLength = 0;
#ftypSize = 0;
#moovSize = 0;
#ftypMoovSize = 0;
#ftypMoovChunks = [];
#ftypMoovChunksTotalLength = 0;
#moofSize = 0;
#mdatSize = 0;
#moofMdatSize = 0;
#moofMdatChunks = [];
#moofMdatChunksTotalLength = 0;
#smallChunk = undefined; // to be used when chunk is less than 8 bytes and moof/mdat box index cannot be found
/* ----> private fields with getters (readonly) <---- */
#initialization;
#audioCodec;
#videoCodec;
#mime;
#timescale;
#segment;
#sequence;
#duration;
#timestamp;
#keyframe;
#segmentObjects;
#totalDuration;
#totalByteLength;
#allKeyframes;
#m3u8;
/**
* @constructor
* @param {object} [options] - Configuration options.
* @param {boolean} [options.readableObjectMode = false] - If true, segments will be piped out as an object instead of a Buffer.
* @param {string} [options.hlsPlaylistBase] - Base name of files in m3u8 playlist. Must only contain letters and underscores. Must be set to generate m3u8 playlist. e.g. 'front_door'.
* @param {number} [options.hlsPlaylistSize = 4] - Number of segments to use in m3u8 playlist. Must be an integer ranging from 2 to 20.
* @param {number} [options.hlsPlaylistExtra = 0] - Number of extra segments to keep in memory. Must be an integer ranging from 0 to 10.
* @param {boolean} [options.hlsPlaylistInit = true] - Indicates that m3u8 playlist should be generated after [initialization]{@link Mp4Frag#initialization} is created and before media segments are created.
* @param {number} [options.segmentCount = 2] - Number of segments to keep in memory. If using hlsPlaylistBase, value will be calculated from hlsPlaylistSize + hlsPlaylistExtra. Must be an integer ranging from 2 to 30.
* @param {number} [options.pool = 0] - Reuse pooled ArrayBuffer allocations to reduce garbage collection. Set to 1 to activate. Experimental.
* @throws Will throw an error if options.hlsPlaylistBase contains characters other than letters(a-zA-Z) and underscores(_).
*/
constructor(options) {
options = options instanceof Object ? options : {};
super({ writableObjectMode: false, readableObjectMode: options.readableObjectMode === true });
if (typeof options.hlsPlaylistBase !== 'undefined') {
if (/[^a-z_]/gi.test(options.hlsPlaylistBase)) {
throw Mp4Frag.#createError('hlsPlaylistBase must only contain underscores and letters (_, a-z, A-Z)', Mp4Frag.#ERR.invalidArg);
/*return process.nextTick(() => {
this.#emitError('hlsPlaylistBase must only contain underscores and letters (_, a-z, A-Z)', Mp4Frag.#ERR.invalidArg);
});*/
}
this.#hlsPlaylist = {
base: options.hlsPlaylistBase,
init: Mp4Frag.#validateBool(options.hlsPlaylistInit, Mp4Frag.#HLS_INIT_DEF),
size: Mp4Frag.#validateInt(options.hlsPlaylistSize, Mp4Frag.#HLS_SIZE.def, Mp4Frag.#HLS_SIZE.min, Mp4Frag.#HLS_SIZE.max),
extra: Mp4Frag.#validateInt(options.hlsPlaylistExtra, Mp4Frag.#HLS_EXTRA.def, Mp4Frag.#HLS_EXTRA.min, Mp4Frag.#HLS_EXTRA.max),
};
this.#segmentCount = this.#hlsPlaylist.size + this.#hlsPlaylist.extra;
this.#segmentObjects = [];
} else if (typeof options.segmentCount !== 'undefined') {
this.#segmentCount = Mp4Frag.#validateInt(options.segmentCount, Mp4Frag.#SEG_SIZE.def, Mp4Frag.#SEG_SIZE.min, Mp4Frag.#SEG_SIZE.max);
this.#segmentObjects = [];
}
if (options.pool > 0) {
this.#poolLength = (this.#segmentCount || 1) + options.pool;
this.#bufferPool = new BufferPool({ length: this.#poolLength });
this.#bufferConcat = this.#bufferPool.concat.bind(this.#bufferPool);
}
if (options.readableObjectMode === true) {
this.#sendInit = this.#sendInitAsObject;
this.#sendSegment = this.#sendSegmentAsObject;
}
/*
todo after version 0.7.0
this.on('newListener', event => {
if (event === 'initialized') {
deprecate(() => {}, '"initialized" event will be removed in version >= 0.8.0. Please use "data" event and check for type: init.')();
} else if (event === 'segment') {
deprecate(() => {}, '"segment" event will be removed in version >= 0.8.0. Please use "data" event and check for type: segment.')();
}
});
*/
this.#parseChunk = this.#findFtyp;
}
/**
* @readonly
* @property {string|null} audioCodec
* - Returns the audio codec information as a <b>string</b>.
* <br/>
* - Returns <b>null</b> if requested before [initialized event]{@link Mp4Frag#event:initialized}.
* @returns {string|null}
*/
get audioCodec() {
return this.#audioCodec || null;
}
/**
* @readonly
* @property {string|null} videoCodec
* - Returns the video codec information as a <b>string</b>.
* <br/>
* - Returns <b>null</b> if requested before [initialized event]{@link Mp4Frag#event:initialized}.
* @returns {string|null}
*/
get videoCodec() {
return this.#videoCodec || null;
}
/**
* @readonly
* @property {string|null} mime
* - Returns the mime type information as a <b>string</b>.
* <br/>
* - Returns <b>null</b> if requested before [initialized event]{@link Mp4Frag#event:initialized}.
* @returns {string|null}
*/
get mime() {
return this.#mime || null;
}
/**
* @readonly
* @property {number} timescale
* - Returns the timescale information as a <b>number</b>.
* <br/>
* - Returns <b>-1</b> if requested before [initialized event]{@link Mp4Frag#event:initialized}.
* @returns {number}
*/
get timescale() {
return this.#timescale || -1;
}
/**
* @readonly
* @property {Buffer|null} initialization
* - Returns the Mp4 initialization fragment as a <b>Buffer</b>.
* <br/>
* - Returns <b>null</b> if requested before [initialized event]{@link Mp4Frag#event:initialized}.
* @returns {Buffer|null}
*/
get initialization() {
return this.#initialization || null;
}
/**
* @readonly
* @property {number} poolLength
* - Returns the number of array buffers in pool
* <br/>
* - Returns <b>-1</b> if pool not in use.
* @returns {number}
*/
get poolLength() {
return this.#poolLength || -1;
}
/**
* @readonly
* @property {Buffer|null} segment
* - Returns the latest Mp4 segment as a <b>Buffer</b>.
* <br/>
* - Returns <b>null</b> if requested before first [segment event]{@link Mp4Frag#event:segment}.
* @returns {Buffer|null}
*/
get segment() {
return this.#segment || null;
}
/**
* @readonly
* @property {object} segmentObject
* - Returns the latest Mp4 segment as an <b>object</b>.
* <br/>
* - <b><code>{segment, sequence, duration, timestamp, keyframe}</code></b>
* <br/>
* - Returns <b>{segment: null, sequence: -1, duration: -1; timestamp: -1, keyframe: true}</b> if requested before first [segment event]{@link Mp4Frag#event:segment}.
* @returns {object}
*/
get segmentObject() {
return {
segment: this.segment,
sequence: this.sequence,
duration: this.duration,
timestamp: this.timestamp,
keyframe: this.keyframe,
};
}
/**
* @readonly
* @property {number} timestamp
* - Returns the timestamp of the latest Mp4 segment as an <b>Integer</b>(<i>milliseconds</i>).
* <br/>
* - Returns <b>-1</b> if requested before first [segment event]{@link Mp4Frag#event:segment}.
* @returns {number}
*/
get timestamp() {
return this.#timestamp || -1;
}
/**
* @readonly
* @property {number} duration
* - Returns the duration of latest Mp4 segment as a <b>Float</b>(<i>seconds</i>).
* <br/>
* - Returns <b>-1</b> if requested before first [segment event]{@link Mp4Frag#event:segment}.
* @returns {number}
*/
get duration() {
return this.#duration || -1;
}
/**
* @readonly
* @property {number} totalDuration
* - Returns the total duration of all Mp4 segments as a <b>Float</b>(<i>seconds</i>).
* <br/>
* - Returns <b>-1</b> if requested before first [segment event]{@link Mp4Frag#event:segment}.
* @returns {number}
*/
get totalDuration() {
return this.#totalDuration || -1;
}
/**
* @readonly
* @property {number} totalByteLength
* - Returns the total byte length of the Mp4 initialization and all Mp4 segments as an <b>Integer</b>(<i>bytes</i>).
* <br/>
* - Returns <b>-1</b> if requested before [initialized event]{@link Mp4Frag#event:initialized}.
* @returns {number}
*/
get totalByteLength() {
return this.#totalByteLength || -1;
}
/**
* @readonly
* @property {string|null} m3u8
* - Returns the fmp4 HLS m3u8 playlist as a <b>string</b>.
* <br/>
* - Returns <b>null</b> if requested before [initialized event]{@link Mp4Frag#event:initialized}.
* @returns {string|null}
*/
get m3u8() {
return this.#m3u8 || null;
}
/**
* @readonly
* @property {number} sequence
* - Returns the sequence of the latest Mp4 segment as an <b>Integer</b>.
* <br/>
* - Returns <b>-1</b> if requested before first [segment event]{@link Mp4Frag#event:segment}.
* @returns {number}
*/
get sequence() {
return Number.isInteger(this.#sequence) ? this.#sequence : -1;
}
/**
* @readonly
* @property {boolean} keyframe
* - Returns a boolean indicating if the current segment contains a keyframe.
* <br/>
* - Returns <b>false</b> if the current segment does not contain a keyframe.
* <br/>
* - Returns <b>true</b> if segment only contains audio.
* @returns {boolean}
*/
get keyframe() {
return typeof this.#keyframe === 'boolean' ? this.#keyframe : true;
}
/**
* @readonly
* @property {boolean} allKeyframes
* - Returns a boolean indicating if all segments contain a keyframe.
* <br/>
* - Returns <b>false</b> if any segments do not contain a keyframe.
* @returns {boolean}
*/
get allKeyframes() {
return typeof this.#allKeyframes === 'boolean' ? this.#allKeyframes : true;
}
/**
* @readonly
* @property {Array|null} segmentObjects
* - Returns the Mp4 segments as an <b>Array</b> of <b>objects</b>
* <br/>
* - <b><code>[{segment, sequence, duration, timestamp, keyframe},...]</code></b>
* <br/>
* - Returns <b>null</b> if requested before first [segment event]{@link Mp4Frag#event:segment}.
* @returns {Array|null}
*/
get segmentObjects() {
return this.#segmentObjects && this.#segmentObjects.length ? this.#segmentObjects : null;
}
/**
* @param {number|string} sequence - sequence number
* - Returns the Mp4 segment that corresponds to the numbered sequence as an <b>object</b>.
* <br/>
* - <b><code>{segment, sequence, duration, timestamp, keyframe}</code></b>
* <br/>
* - Returns <b>null</b> if there is no segment that corresponds to sequence number.
* @returns {object|null}
*/
getSegmentObject(sequence) {
sequence = Number.parseInt(sequence);
if (this.#segmentObjects && this.#segmentObjects.length) {
return this.#segmentObjects[this.#segmentObjects.length - 1 - (this.#sequence - sequence)] || null;
}
return null;
}
/**
* Clear cached values
*/
resetCache() {
/*
todo after version 0.7.0
deprecate
*/
this.reset();
}
/**
* Clear cached values
*/
reset() {
this.emit('reset');
this.#parseChunk = this.#findFtyp;
if (this.#segmentObjects) {
this.#segmentObjects = [];
}
this.#timescale = undefined;
this.#sequence = undefined;
this.#allKeyframes = undefined;
this.#keyframe = undefined;
this.#mime = undefined;
this.#videoCodec = undefined;
this.#audioCodec = undefined;
this.#initialization = undefined;
this.#segment = undefined;
this.#timestamp = undefined;
this.#duration = undefined;
this.#totalDuration = undefined;
this.#totalByteLength = undefined;
this.#m3u8 = undefined;
this.#setKeyframe = this.#noop;
this.#resetFtypMoov();
this.#resetMoofMdat();
if (this.#bufferPool) {
this.#bufferPool.reset();
}
}
/**
*
* @returns {object}
*/
toJSON() {
return {
initialization: this.initialization,
audioCodec: this.audioCodec,
videoCodec: this.videoCodec,
mime: this.mime,
timescale: this.timescale,
poolLength: this.poolLength,
segmentObject: this.segmentObject,
segmentObjects: this.segmentObjects,
totalDuration: this.totalDuration,
totalByteLength: this.totalByteLength,
allKeyframes: this.allKeyframes,
m3u8: this.m3u8,
};
}
/**
* @private
*/
#noop() {}
/**
*
* @param {string} msg
* @param {string} code
* @private
*/
#emitError(msg, code) {
this.#parseChunk = this.#noop;
this.emit('error', Mp4Frag.#createError(msg, code));
}
/**
* Search buffer for ftyp.
* @param {Buffer} chunk
* @private
*/
#findFtyp(chunk) {
const chunkLength = chunk.length;
if (chunk.indexOf(Mp4Frag.#FTYP) === 4) {
this.#ftypSize = chunk.readUInt32BE(0);
if (this.#ftypSize === chunkLength) {
this.#ftypMoovChunks.push(chunk);
this.#ftypMoovChunksTotalLength += chunkLength;
this.#parseChunk = this.#findMoov;
} else if (this.#ftypSize < chunkLength) {
// recursive
this.#ftypMoovChunks.push(chunk.subarray(0, this.#ftypSize));
this.#ftypMoovChunksTotalLength += this.#ftypSize;
const nextChunk = chunk.subarray(this.#ftypSize);
this.#parseChunk = this.#findMoov;
this.#parseChunk(nextChunk);
} else {
this.#emitError(`ftypSize:${this.#ftypSize} > chunkLength:${chunkLength}.`, Mp4Frag.#ERR.chunkLength);
}
} else {
this.#emitError(`${Mp4Frag.#FTYP.toString()} not found. chunkLength:${chunkLength}.`, Mp4Frag.#ERR.chunkParse);
}
}
/**
* Search buffer for moov.
* @param {Buffer} chunk
* @private
*/
#findMoov(chunk) {
const chunkLength = chunk.length;
if (chunk.indexOf(Mp4Frag.#MOOV) === 4) {
this.#moovSize = chunk.readUInt32BE(0);
this.#ftypMoovSize = this.#ftypSize + this.#moovSize;
if (this.#moovSize === chunkLength) {
this.#ftypMoovChunks.push(chunk);
this.#ftypMoovChunksTotalLength += chunkLength;
this.#handleFtypMoov();
this.#parseChunk = this.#findMoof;
} else if (this.#moovSize < chunkLength) {
// recursive
this.#ftypMoovChunks.push(chunk.subarray(0, this.#moovSize));
this.#ftypMoovChunksTotalLength += this.#moovSize;
const nextChunk = chunk.subarray(this.#moovSize);
this.#handleFtypMoov();
this.#parseChunk = this.#findMoof;
this.#parseChunk(nextChunk);
} else {
this.#emitError(`moovSize:${this.#moovSize} > chunkLength:${chunkLength}.`, Mp4Frag.#ERR.chunkLength);
}
} else {
this.#emitError(`${Mp4Frag.#MOOV.toString()} not found. chunkLength:${chunkLength}.`, Mp4Frag.#ERR.chunkParse);
}
}
#resetFtypMoov() {
this.#ftypSize = this.#moovSize = this.#ftypMoovSize = this.#ftypMoovChunks.length = this.#ftypMoovChunksTotalLength = 0;
}
#handleFtypMoov() {
const ftypMoov = ((list, totalLength) => {
if (list.length === 2) {
const [ftyp, moov] = list;
if (ftyp.buffer === moov.buffer && ftyp.buffer.byteLength === totalLength) {
return Buffer.from(ftyp.buffer);
}
}
let bytesCopied = 0;
const buffer = Buffer.allocUnsafeSlow(totalLength);
list.forEach(chunk => {
bytesCopied += chunk.copy(buffer, bytesCopied);
});
return buffer;
})(this.#ftypMoovChunks, this.#ftypMoovChunksTotalLength);
this.#resetFtypMoov();
this.#initialize(ftypMoov);
}
/**
* Search buffer for moof.
* @param {Buffer} chunk
* @private
*/
#findMoof(chunk) {
const chunkLength = chunk.length;
if (this.#moofSize) {
if (this.#moofSize === this.#moofMdatChunksTotalLength + chunkLength) {
this.#moofMdatChunks.push(chunk);
this.#moofMdatChunksTotalLength += chunkLength;
this.#parseChunk = this.#findMdat;
} else if (this.#moofSize < this.#moofMdatChunksTotalLength + chunkLength) {
// recursive
const finalChunkSize = this.#moofSize - this.#moofMdatChunksTotalLength;
this.#moofMdatChunks.push(chunk.subarray(0, finalChunkSize));
this.#moofMdatChunksTotalLength += finalChunkSize;
const nextChunk = chunk.subarray(finalChunkSize);
this.#parseChunk = this.#findMdat;
this.#parseChunk(nextChunk);
} else {
this.#moofMdatChunks.push(chunk);
this.#moofMdatChunksTotalLength += chunkLength;
}
} else {
if (chunk.indexOf(Mp4Frag.#MOOF) === 4) {
this.#moofSize = chunk.readUInt32BE(0);
if (this.#moofSize === chunkLength) {
this.#moofMdatChunks.push(chunk);
this.#moofMdatChunksTotalLength += chunkLength;
this.#parseChunk = this.#findMdat;
} else if (this.#moofSize < chunkLength) {
// recursive
this.#moofMdatChunks.push(chunk.subarray(0, this.#moofSize));
this.#moofMdatChunksTotalLength += this.#moofSize;
const nextChunk = chunk.subarray(this.#moofSize);
this.#parseChunk = this.#findMdat;
this.#parseChunk(nextChunk);
} else {
this.#moofMdatChunks.push(chunk);
this.#moofMdatChunksTotalLength += chunkLength;
}
} else {
if (chunk.indexOf(Mp4Frag.#MFRA) === 4) {
// console.log(`\nend of segments ${Mp4Frag.#MFRA.toString()}\n`);
this.#parseChunk = this.#noop;
} else {
if (this.#smallChunk) {
// recursive
const repairedChunk = Buffer.concat([this.#smallChunk, chunk]);
this.#smallChunk = undefined;
this.#parseChunk(repairedChunk);
} else if (chunkLength < 8) {
this.#smallChunk = chunk;
} else {
this.#emitError(`${Mp4Frag.#MOOF.toString()} not found. chunkLength:${chunkLength}.`, Mp4Frag.#ERR.chunkParse);
}
}
}
}
}
/**
* Search buffer for mdat.
* @param {Buffer} chunk
* @private
*/
#findMdat(chunk) {
const chunkLength = chunk.length;
if (this.#mdatSize) {
if (this.#moofMdatSize === this.#moofMdatChunksTotalLength + chunkLength) {
this.#moofMdatChunks.push(chunk);
this.#moofMdatChunksTotalLength += chunkLength;
this.#handleMoofMdat();
this.#parseChunk = this.#findMoof;
} else if (this.#moofMdatSize < this.#moofMdatChunksTotalLength + chunkLength) {
// recursive
const finalChunkSize = this.#moofMdatSize - this.#moofMdatChunksTotalLength;
this.#moofMdatChunks.push(chunk.subarray(0, finalChunkSize));
this.#moofMdatChunksTotalLength += finalChunkSize;
const nextChunk = chunk.subarray(finalChunkSize);
this.#handleMoofMdat();
this.#parseChunk = this.#findMoof;
this.#parseChunk(nextChunk);
} else {
this.#moofMdatChunks.push(chunk);
this.#moofMdatChunksTotalLength += chunkLength;
}
} else {
if (chunk.indexOf(Mp4Frag.#MDAT) === 4) {
this.#mdatSize = chunk.readUInt32BE(0);
this.#moofMdatSize = this.#moofSize + this.#mdatSize;
if (this.#mdatSize === chunkLength) {
this.#moofMdatChunks.push(chunk);
this.#moofMdatChunksTotalLength += chunkLength;
this.#handleMoofMdat();
this.#parseChunk = this.#findMoof;
} else if (this.#mdatSize < chunkLength) {
// recursive
this.#moofMdatChunks.push(chunk.subarray(0, this.#mdatSize));
this.#moofMdatChunksTotalLength += this.#mdatSize;
const nextChunk = chunk.subarray(this.#mdatSize);
this.#handleMoofMdat();
this.#parseChunk = this.#findMoof;
this.#parseChunk(nextChunk);
} else {
this.#moofMdatChunks.push(chunk);
this.#moofMdatChunksTotalLength += chunkLength;
}
} else {
if (this.#smallChunk) {
const repairedChunk = Buffer.concat([this.#smallChunk, chunk]);
this.#smallChunk = undefined;
this.#parseChunk(repairedChunk);
} else if (chunkLength < 8) {
this.#smallChunk = chunk;
} else {
this.#emitError(`${Mp4Frag.#MDAT.toString()} not found. chunkLength:${chunkLength}.`, Mp4Frag.#ERR.chunkParse);
}
}
}
}
#resetMoofMdat() {
this.#moofSize = this.#mdatSize = this.#moofMdatSize = this.#moofMdatChunks.length = this.#moofMdatChunksTotalLength = 0;
}
#handleMoofMdat() {
const moofMdat = ((list, totalLength) => {
if (list.length === 2) {
const [moof, mdat] = list;
if (moof.buffer === mdat.buffer && moof.byteOffset + moof.length === mdat.byteOffset) {
return Buffer.from(moof.buffer, moof.byteOffset, totalLength);
}
}
return this.#bufferConcat(list, totalLength);
})(this.#moofMdatChunks, this.#moofMdatChunksTotalLength);
this.#resetMoofMdat();
this.#setSegment(moofMdat);
}
/**
* Parse moov for mime.
* @fires Mp4Frag#initialized
* @param {Buffer} chunk
* @private
*/
#initialize(chunk) {
this.#initialization = chunk;
const mdhdIndex = chunk.indexOf(Mp4Frag.#MDHD);
const mdhdVersion = chunk[mdhdIndex + 4];
this.#timescale = chunk.readUInt32BE(mdhdIndex + (mdhdVersion === 0 ? 16 : 24));
this.#timestamp = Date.now();
this.#sequence = -1;
this.#allKeyframes = true;
this.#totalDuration = 0;
this.#totalByteLength = chunk.byteLength;
const codecs = [];
let mp4Type;
if (this.#parseCodecAVCC(chunk) || this.#parseCodecHVCC(chunk)) {
codecs.push(this.#videoCodec);
mp4Type = 'video';
}
if (this.#parseCodecMP4A(chunk)) {
codecs.push(this.#audioCodec);
if (!this.#videoCodec) {
mp4Type = 'audio';
}
}
if (codecs.length === 0) {
this.#emitError('codecs not found.', Mp4Frag.#ERR.chunkParse);
return;
}
this.#mime = `${mp4Type}/mp4; codecs="${codecs.join(', ')}"`;
if (this.#hlsPlaylist && this.#hlsPlaylist.init) {
let m3u8 = '#EXTM3U\n';
m3u8 += '#EXT-X-VERSION:7\n';
m3u8 += `#EXT-X-TARGETDURATION:1\n`;
m3u8 += `#EXT-X-MEDIA-SEQUENCE:0\n`;
m3u8 += `#EXT-X-MAP:URI="init-${this.#hlsPlaylist.base}.mp4"\n`;
this.#m3u8 = m3u8;
}
this.#sendInit();
/*
todo after version 0.7.0
replace with emit('data')
*/
this.emit('initialized', { mime: this.mime, initialization: this.initialization, m3u8: this.m3u8 });
}
/**
* @private
*/
#sendInitAsBuffer() {
this.emit('data', this.initialization, { type: 'init', mime: this.mime, m3u8: this.m3u8 });
}
/**
* @private
*/
#sendInitAsObject() {
this.emit('data', { type: 'init', initialization: this.initialization, mime: this.mime, m3u8: this.m3u8 });
}
/**
* Set hvcC keyframe.
* @param {Buffer} chunk
* @private
*/
#setKeyframeHVCC(chunk) {
// let index = this.#moofSize + 8;
let index = chunk.indexOf(Mp4Frag.#MDAT) + 4;
const end = chunk.length - 5;
while (index < end) {
const nalLength = chunk.readUInt32BE(index);
// simplify check for iframe nal types 16, 17, 18, 19, 20, 21; (chunk[(index += 4)] & 0x20) >> 1
if ((chunk[(index += 4)] & 0x20) === 32) {
this.#keyframe = true;
return;
}
index += nalLength;
}
this.#allKeyframes = false;
this.#keyframe = false;
}
/**
* Set avcC keyframe.
* @see {@link https://github.com/video-dev/hls.js/blob/729a36d409cc78cc391b17a0680eaf743f9213fb/tools/mp4-inspect.js#L48}
* @param {Buffer} chunk
* @private
*/
#setKeyframeAVCC(chunk) {
// let index = this.#moofSize + 8;
let index = chunk.indexOf(Mp4Frag.#MDAT) + 4;
const end = chunk.length - 5;
while (index < end) {
const nalLength = chunk.readUInt32BE(index);
if ((chunk[(index += 4)] & 0x1f) === 5) {
this.#keyframe = true;
return;
}
index += nalLength;
}
this.#allKeyframes = false;
this.#keyframe = false;
}
/**
* Get duration of segment.
* @see {@link https://github.com/video-dev/hls.js/blob/04cc5f167dac2aed4e41e493125968838cb32445/src/utils/mp4-tools.ts#L392}
* @param {Buffer} chunk
* @private
*/
#parseDuration(chunk) {
const trunIndex = chunk.indexOf(Mp4Frag.#TRUN);
let trunOffset = trunIndex + 4;
const trunFlags = chunk.readUInt32BE(trunOffset);
trunOffset += 4;
const sampleCount = chunk.readUInt32BE(trunOffset);
// prefer using trun sample durations
if (trunFlags & 0x000100) {
trunOffset += 4;
trunFlags & 0x000001 && (trunOffset += 4);
trunFlags & 0x000004 && (trunOffset += 4);
const increment = 4 + (trunFlags & 0x000200 && 4) + (trunFlags & 0x000400 && 4) + (trunFlags & 0x000800 && 4);
let sampleDurationSum = 0;
for (let i = 0; i < sampleCount; ++i, trunOffset += increment) {
sampleDurationSum += chunk.readUInt32BE(trunOffset);
}
return sampleDurationSum / this.#timescale;
}
// fallback to using tfhd default sample duration
const tfhdIndex = chunk.indexOf(Mp4Frag.#TFHD);
let tfhdOffset = tfhdIndex + 4;
const tfhdFlags = chunk.readUInt32BE(tfhdOffset);
if (tfhdFlags & 0x000008) {
tfhdOffset += 8;
tfhdFlags & 0x000001 && (tfhdOffset += 8);
tfhdFlags & 0x000002 && (tfhdOffset += 4);
return (chunk.readUInt32BE(tfhdOffset) * sampleCount) / this.#timescale;
}
return 0;
}
/**
* Set duration and timestamp.
* @param {Buffer} chunk
* @private
*/
#setDurTime(chunk) {
const duration = this.#parseDuration(chunk);
const currentTime = Date.now();
this.#duration = duration || (currentTime - this.#timestamp) / 1000;
this.#timestamp = currentTime;
}
/**
* Process current segment.
* @fires Mp4Frag#segment
* @param {Buffer} chunk
* @private
*/
#setSegment(chunk) {
this.#segment = chunk;
this.#setKeyframe(chunk);
this.#setDurTime(chunk);
this.#sequence++;
if (this.#segmentObjects) {
this.#segmentObjects.push({
segment: chunk,
sequence: this.#sequence,
duration: this.#duration,
timestamp: this.#timestamp,
keyframe: this.#keyframe,
});
this.#totalDuration += this.#duration;
this.#totalByteLength += chunk.byteLength;
while (this.#segmentObjects.length > this.#segmentCount) {
const {
duration,
segment: { byteLength },
} = this.#segmentObjects.shift();
this.#totalDuration -= duration;
this.#totalByteLength -= byteLength;
}
if (this.#hlsPlaylist) {
let i = this.#segmentObjects.length > this.#hlsPlaylist.size ? this.#segmentObjects.length - this.#hlsPlaylist.size : 0;
const mediaSequence = this.#segmentObjects[i].sequence;
let targetDuration = 1;
let segments = '';
for (i; i < this.#segmentObjects.length; ++i) {
targetDuration = Math.max(targetDuration, this.#segmentObjects[i].duration);
segments += `#EXTINF:${this.#segmentObjects[i].duration.toFixed(6)},\n`;
segments += `${this.#hlsPlaylist.base}${this.#segmentObjects[i].sequence}.m4s\n`;
}
let m3u8 = '#EXTM3U\n';
m3u8 += '#EXT-X-VERSION:7\n';
m3u8 += `#EXT-X-TARGETDURATION:${Math.round(targetDuration) || 1}\n`;
m3u8 += `#EXT-X-MEDIA-SEQUENCE:${mediaSequence}\n`;
m3u8 += `#EXT-X-MAP:URI="init-${this.#hlsPlaylist.base}.mp4"\n`;
m3u8 += segments;
this.#m3u8 = m3u8;
}
} else {
this.#totalDuration = this.#duration;
this.#totalByteLength = this.#initialization.byteLength + chunk.byteLength;
}
this.#sendSegment();
/*
todo after version 0.7.0
replace with emit('data')
*/
this.emit('segment', this.segmentObject);
}
/**
* @private
*/
#sendSegmentAsBuffer() {
this.emit('data', this.segment, { type: 'segment', sequence: this.sequence, duration: this.duration, timestamp: this.timestamp, keyframe: this.keyframe });
}
/**
* @private
*/
#sendSegmentAsObject() {
this.emit('data', { type: 'segment', segment: this.segment, sequence: this.sequence, duration: this.duration, timestamp: this.timestamp, keyframe: this.keyframe });
}
/**
* @param {Buffer} chunk
* @returns {boolean}
* @private
*/
#parseCodecMP4A(chunk) {
const index = chunk.indexOf(Mp4Frag.#MP4A);
if (index !== -1) {
const codec = ['mp4a'];
const esdsIndex = chunk.indexOf(Mp4Frag.#ESDS, index);
// verify tags 3, 4, 5 to be in expected positions
if (esdsIndex !== -1 && chunk[esdsIndex + 8] === 0x03 && chunk[esdsIndex + 16] === 0x04 && chunk[esdsIndex + 34] === 0x05) {
codec.push(chunk[esdsIndex + 21].toString(16));
codec.push(((chunk[esdsIndex + 39] & 0xf8) >> 3).toString());
this.#audioCodec = codec.join('.');
return true;
}
// console.warn('unexpected mp4a esds structure');
}
return false;
}
/**
* @param {Buffer} chunk
* @returns {boolean}
* @private
*/
#parseCodecAVCC(chunk) {
const index = chunk.indexOf(Mp4Frag.#AVCC);
if (index !== -1) {
const codec = [];
if (chunk.includes(Mp4Frag.#AVC1)) {
codec.push('avc1');
} else if (chunk.includes(Mp4Frag.#AVC2)) {
codec.push('avc2');
} else if (chunk.includes(Mp4Frag.#AVC3)) {
codec.push('avc3');
} else if (chunk.includes(Mp4Frag.#AVC4)) {
codec.push('avc4');
} else {
return false;
}
codec.push(
chunk
.subarray(index + 5, index + 8)
.toString('hex')
.toUpperCase()
);
this.#videoCodec = codec.join('.');
this.#setKeyframe = this.#setKeyframeAVCC;
return true;
}
return false;
}
/**
* @param {Buffer} chunk
* @returns {boolean}
* @private
*/
#parseCodecHVCC(chunk) {
const index = chunk.indexOf(Mp4Frag.#HVCC);
if (index !== -1) {
const codec = [];
if (chunk.includes(Mp4Frag.#HVC1)) {
codec.push('hvc1');
} else if (chunk.includes(Mp4Frag.#HEV1)) {
codec.push('hev1');
} else {
return false;
}
const tmpByte = chunk[index + 5];
const generalProfileSpace = tmpByte >> 6; // get 1st 2 bits (11000000)
const generalTierFlag = !!(tmpByte & 0x20) ? 'H' : 'L'; // get next bit (00100000)
const generalProfileIdc = (tmpByte & 0x1f).toString(); // get last 5 bits (00011111)
const generalProfileCompatibility = Mp4Frag.#reverseBitsToHex(chunk.readUInt32BE(index + 6));
const generalConstraintIndicator = Buffer.from(chunk.subarray(index + 10, index + 16).filter(byte => !!byte)).toString('hex');
const generalLevelIdc = chunk[index + 16].toString();
switch (generalProfileSpace) {
case 0:
codec.push(generalProfileIdc);
break;
case 1:
codec.push(`A${generalProfileIdc}`);
break;
case 2:
codec.push(`B${generalProfileIdc}`);
break;
case 3:
codec.push(`C${generalProfileIdc}`);
break;
}
codec.push(generalProfileCompatibility);
codec.push(`${generalTierFlag}${generalLevelIdc}`);
if (generalConstraintIndicator.length) {
codec.push(generalConstraintIndicator);
}
this.#videoCodec = codec.join('.');
this.#setKeyframe = this.#setKeyframeHVCC;
return true;
}
return false;
}
/**
* Required for stream transform.
* @param {Buffer} chunk
* @param {string} encoding
* @param {TransformCallback} callback
* @private
*/
_transform(chunk, encoding, callback) {
this.#parseChunk(chunk);
callback();
}
/**
* Run cleanup when unpiped.
* @param {TransformCallback} callback
* @private
*/
_flush(callback) {
this.reset();
callback();
}
/**
* Validate number is in range.
* @param {number|string} n
* @param {number} def
* @param {number} min
* @param {number} max
* @returns {number}
* @private
* @static
*/
static #validateInt(n, def, min, max) {
n = Number.parseInt(n);
return isNaN(n) ? def : n < min ? min : n > max ? max : n;
}
/**
* Validate boolean value.
* @param {*} bool
* @param {boolean} def
* @returns {boolean}
* @private
* @static
*/
static #validateBool(bool, def) {
return typeof bool === 'boolean' ? bool : def;
}
/**
* Reverse bits and convert to hexadecimal.
* @see {@link http://graphics.stanford.edu/~seander/bithacks.html#ReverseParallel}
* @param {number} n - unsigned 32-bit integer
* @returns {string} - bit reversed hex string
* @private
* @static
*/
static #reverseBitsToHex(n) {
n = ((n >> 1) & 0x55555555) | ((n & 0x55555555) << 1);
n = ((n >> 2) & 0x33333333) | ((n & 0x33333333) << 2);
n = ((n >> 4) & 0x0f0f0f0f) | ((n & 0x0f0f0f0f) << 4);
n = ((n >> 8) & 0x00ff00ff) | ((n & 0x00ff00ff) << 8);
return ((n >> 16) | (n << 16)).toString(16);
}
/**
* Create box Buffer.
* @param {number[]} arr
* @returns {Buffer}
* @private
* @static
*/
static #boxFrom(arr) {
const buffer = Buffer.allocUnsafeSlow(4);
for (let i = 0; i < 4; ++i) {
buffer[i] = arr[i];
}
return buffer;
}
/**
*
* @param {string} msg
* @param {string} code
* @returns {Error}
* @private
* @static
*/
static #createError(msg, code) {
const error = new Error(msg);
error.code = code;
return error;
}
}
/**
* Fires when the [initialization]{@link Mp4Frag#initialization} of the Mp4 is parsed from the piped data.
* @event Mp4Frag#initialized
* @type {Event}
* @property {object} object
* @property {string} object.mime - [Mp4Frag.mime]{@link Mp4Frag#mime}
* @property {Buffer} object.initialization - [Mp4Frag.initialization]{@link Mp4Frag#initialization}
* @property {string} object.m3u8 - [Mp4Frag.m3u8]{@link Mp4Frag#m3u8}
*/
/**
* Fires when the latest Mp4 segment is parsed from the piped data.
* @event Mp4Frag#segment
* @type {Event}
* @property {object} object - [Mp4Frag.segmentObject]{@link Mp4Frag#segmentObject}
* @property {Buffer} object.segment - [Mp4Frag.segment]{@link Mp4Frag#segment}
* @property {number} object.sequence - [Mp4Frag.sequence]{@link Mp4Frag#sequence}
* @property {number} object.duration - [Mp4Frag.duration]{@link Mp4Frag#duration}
* @property {number} object.timestamp - [Mp4Frag.timestamp]{@link Mp4Frag#timestamp}
* @property {number} object.keyframe - [Mp4Frag.keyframe]{@link Mp4Frag#keyframe}
*/
/**
* Fires when reset() is called.
* @event Mp4Frag#reset
* @type {Event}
*/
module.exports = Mp4Frag;