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jellyfin-web/dashboard-ui/bower_components/hls.js/src/demux/tsdemuxer.js
2016-02-03 18:00:01 -05:00

632 lines
21 KiB
JavaScript

/**
* highly optimized TS demuxer:
* parse PAT, PMT
* extract PES packet from audio and video PIDs
* extract AVC/H264 NAL units and AAC/ADTS samples from PES packet
* trigger the remuxer upon parsing completion
* it also tries to workaround as best as it can audio codec switch (HE-AAC to AAC and vice versa), without having to restart the MediaSource.
* it also controls the remuxing process :
* upon discontinuity or level switch detection, it will also notifies the remuxer so that it can reset its state.
*/
import ADTS from './adts';
import Event from '../events';
import ExpGolomb from './exp-golomb';
// import Hex from '../utils/hex';
import {logger} from '../utils/logger';
import {ErrorTypes, ErrorDetails} from '../errors';
class TSDemuxer {
constructor(observer,remuxerClass) {
this.observer = observer;
this.remuxerClass = remuxerClass;
this.lastCC = 0;
this.remuxer = new this.remuxerClass(observer);
this._userData = [];
}
static probe(data) {
// a TS fragment should contain at least 3 TS packets, a PAT, a PMT, and one PID, each starting with 0x47
if (data.length >= 3*188 && data[0] === 0x47 && data[188] === 0x47 && data[2*188] === 0x47) {
return true;
} else {
return false;
}
}
switchLevel() {
this.pmtParsed = false;
this._pmtId = -1;
this.lastAacPTS = null;
this.aacOverFlow = null;
this._avcTrack = {type: 'video', id :-1, sequenceNumber: 0, samples : [], len : 0, nbNalu : 0};
this._aacTrack = {type: 'audio', id :-1, sequenceNumber: 0, samples : [], len : 0};
this._id3Track = {type: 'id3', id :-1, sequenceNumber: 0, samples : [], len : 0};
this._txtTrack = {type: 'text', id: -1, sequenceNumber: 0, samples: [], len: 0};
this.remuxer.switchLevel();
}
insertDiscontinuity() {
this.switchLevel();
this.remuxer.insertDiscontinuity();
}
// feed incoming data to the front of the parsing pipeline
push(data, audioCodec, videoCodec, timeOffset, cc, level, sn, duration) {
var avcData, aacData, id3Data,
start, len = data.length, stt, pid, atf, offset;
this.audioCodec = audioCodec;
this.videoCodec = videoCodec;
this.timeOffset = timeOffset;
this._duration = duration;
this.contiguous = false;
if (cc !== this.lastCC) {
logger.log('discontinuity detected');
this.insertDiscontinuity();
this.lastCC = cc;
} else if (level !== this.lastLevel) {
logger.log('level switch detected');
this.switchLevel();
this.lastLevel = level;
} else if (sn === (this.lastSN+1)) {
this.contiguous = true;
}
this.lastSN = sn;
if(!this.contiguous) {
// flush any partial content
this.aacOverFlow = null;
}
var pmtParsed = this.pmtParsed,
avcId = this._avcTrack.id,
aacId = this._aacTrack.id,
id3Id = this._id3Track.id;
// don't parse last TS packet if incomplete
len -= len % 188;
// loop through TS packets
for (start = 0; start < len; start += 188) {
if (data[start] === 0x47) {
stt = !!(data[start + 1] & 0x40);
// pid is a 13-bit field starting at the last bit of TS[1]
pid = ((data[start + 1] & 0x1f) << 8) + data[start + 2];
atf = (data[start + 3] & 0x30) >> 4;
// if an adaption field is present, its length is specified by the fifth byte of the TS packet header.
if (atf > 1) {
offset = start + 5 + data[start + 4];
// continue if there is only adaptation field
if (offset === (start + 188)) {
continue;
}
} else {
offset = start + 4;
}
if (pmtParsed) {
if (pid === avcId) {
if (stt) {
if (avcData) {
this._parseAVCPES(this._parsePES(avcData));
}
avcData = {data: [], size: 0};
}
if (avcData) {
avcData.data.push(data.subarray(offset, start + 188));
avcData.size += start + 188 - offset;
}
} else if (pid === aacId) {
if (stt) {
if (aacData) {
this._parseAACPES(this._parsePES(aacData));
}
aacData = {data: [], size: 0};
}
if (aacData) {
aacData.data.push(data.subarray(offset, start + 188));
aacData.size += start + 188 - offset;
}
} else if (pid === id3Id) {
if (stt) {
if (id3Data) {
this._parseID3PES(this._parsePES(id3Data));
}
id3Data = {data: [], size: 0};
}
if (id3Data) {
id3Data.data.push(data.subarray(offset, start + 188));
id3Data.size += start + 188 - offset;
}
}
} else {
if (stt) {
offset += data[offset] + 1;
}
if (pid === 0) {
this._parsePAT(data, offset);
} else if (pid === this._pmtId) {
this._parsePMT(data, offset);
pmtParsed = this.pmtParsed = true;
avcId = this._avcTrack.id;
aacId = this._aacTrack.id;
id3Id = this._id3Track.id;
}
}
} else {
this.observer.trigger(Event.ERROR, {type : ErrorTypes.MEDIA_ERROR, details: ErrorDetails.FRAG_PARSING_ERROR, fatal: false, reason: 'TS packet did not start with 0x47'});
}
}
// parse last PES packet
if (avcData) {
this._parseAVCPES(this._parsePES(avcData));
}
if (aacData) {
this._parseAACPES(this._parsePES(aacData));
}
if (id3Data) {
this._parseID3PES(this._parsePES(id3Data));
}
this.remux();
}
remux() {
this.remuxer.remux(this._aacTrack, this._avcTrack, this._id3Track, this._txtTrack, this.timeOffset, this.contiguous);
}
destroy() {
this.switchLevel();
this._initPTS = this._initDTS = undefined;
this._duration = 0;
}
_parsePAT(data, offset) {
// skip the PSI header and parse the first PMT entry
this._pmtId = (data[offset + 10] & 0x1F) << 8 | data[offset + 11];
//logger.log('PMT PID:' + this._pmtId);
}
_parsePMT(data, offset) {
var sectionLength, tableEnd, programInfoLength, pid;
sectionLength = (data[offset + 1] & 0x0f) << 8 | data[offset + 2];
tableEnd = offset + 3 + sectionLength - 4;
// to determine where the table is, we have to figure out how
// long the program info descriptors are
programInfoLength = (data[offset + 10] & 0x0f) << 8 | data[offset + 11];
// advance the offset to the first entry in the mapping table
offset += 12 + programInfoLength;
while (offset < tableEnd) {
pid = (data[offset + 1] & 0x1F) << 8 | data[offset + 2];
switch(data[offset]) {
// ISO/IEC 13818-7 ADTS AAC (MPEG-2 lower bit-rate audio)
case 0x0f:
//logger.log('AAC PID:' + pid);
this._aacTrack.id = pid;
break;
// Packetized metadata (ID3)
case 0x15:
//logger.log('ID3 PID:' + pid);
this._id3Track.id = pid;
break;
// ITU-T Rec. H.264 and ISO/IEC 14496-10 (lower bit-rate video)
case 0x1b:
//logger.log('AVC PID:' + pid);
this._avcTrack.id = pid;
break;
default:
logger.log('unkown stream type:' + data[offset]);
break;
}
// move to the next table entry
// skip past the elementary stream descriptors, if present
offset += ((data[offset + 3] & 0x0F) << 8 | data[offset + 4]) + 5;
}
}
_parsePES(stream) {
var i = 0, frag, pesFlags, pesPrefix, pesLen, pesHdrLen, pesData, pesPts, pesDts, payloadStartOffset;
//retrieve PTS/DTS from first fragment
frag = stream.data[0];
pesPrefix = (frag[0] << 16) + (frag[1] << 8) + frag[2];
if (pesPrefix === 1) {
pesLen = (frag[4] << 8) + frag[5];
pesFlags = frag[7];
if (pesFlags & 0xC0) {
/* PES header described here : http://dvd.sourceforge.net/dvdinfo/pes-hdr.html
as PTS / DTS is 33 bit we cannot use bitwise operator in JS,
as Bitwise operators treat their operands as a sequence of 32 bits */
pesPts = (frag[9] & 0x0E) * 536870912 +// 1 << 29
(frag[10] & 0xFF) * 4194304 +// 1 << 22
(frag[11] & 0xFE) * 16384 +// 1 << 14
(frag[12] & 0xFF) * 128 +// 1 << 7
(frag[13] & 0xFE) / 2;
// check if greater than 2^32 -1
if (pesPts > 4294967295) {
// decrement 2^33
pesPts -= 8589934592;
}
if (pesFlags & 0x40) {
pesDts = (frag[14] & 0x0E ) * 536870912 +// 1 << 29
(frag[15] & 0xFF ) * 4194304 +// 1 << 22
(frag[16] & 0xFE ) * 16384 +// 1 << 14
(frag[17] & 0xFF ) * 128 +// 1 << 7
(frag[18] & 0xFE ) / 2;
// check if greater than 2^32 -1
if (pesDts > 4294967295) {
// decrement 2^33
pesDts -= 8589934592;
}
} else {
pesDts = pesPts;
}
}
pesHdrLen = frag[8];
payloadStartOffset = pesHdrLen + 9;
// trim PES header
stream.data[0] = stream.data[0].subarray(payloadStartOffset);
stream.size -= payloadStartOffset;
//reassemble PES packet
pesData = new Uint8Array(stream.size);
// reassemble the packet
while (stream.data.length) {
frag = stream.data.shift();
pesData.set(frag, i);
i += frag.byteLength;
}
return {data: pesData, pts: pesPts, dts: pesDts, len: pesLen};
} else {
return null;
}
}
_parseAVCPES(pes) {
var track = this._avcTrack,
samples = track.samples,
units = this._parseAVCNALu(pes.data),
units2 = [],
debug = false,
key = false,
length = 0,
expGolombDecoder,
avcSample,
push,
i;
// no NALu found
if (units.length === 0 && samples.length > 0) {
// append pes.data to previous NAL unit
var lastavcSample = samples[samples.length - 1];
var lastUnit = lastavcSample.units.units[lastavcSample.units.units.length - 1];
var tmp = new Uint8Array(lastUnit.data.byteLength + pes.data.byteLength);
tmp.set(lastUnit.data, 0);
tmp.set(pes.data, lastUnit.data.byteLength);
lastUnit.data = tmp;
lastavcSample.units.length += pes.data.byteLength;
track.len += pes.data.byteLength;
}
//free pes.data to save up some memory
pes.data = null;
var debugString = '';
units.forEach(unit => {
switch(unit.type) {
//NDR
case 1:
push = true;
if(debug) {
debugString += 'NDR ';
}
break;
//IDR
case 5:
push = true;
if(debug) {
debugString += 'IDR ';
}
key = true;
break;
//SEI
case 6:
push = true;
if(debug) {
debugString += 'SEI ';
}
expGolombDecoder = new ExpGolomb(unit.data);
// skip frameType
expGolombDecoder.readUByte();
var payloadType = expGolombDecoder.readUByte();
// TODO: there can be more than one payload in an SEI packet...
// TODO: need to read type and size in a while loop to get them all
if (payloadType === 4)
{
var payloadSize = 0;
do {
payloadSize = expGolombDecoder.readUByte();
}
while (payloadSize === 255);
var countryCode = expGolombDecoder.readUByte();
if (countryCode === 181)
{
var providerCode = expGolombDecoder.readUShort();
if (providerCode === 49)
{
var userStructure = expGolombDecoder.readUInt();
if (userStructure === 0x47413934)
{
var userDataType = expGolombDecoder.readUByte();
// Raw CEA-608 bytes wrapped in CEA-708 packet
if (userDataType === 3)
{
var firstByte = expGolombDecoder.readUByte();
var secondByte = expGolombDecoder.readUByte();
var totalCCs = 31 & firstByte;
var byteArray = [firstByte, secondByte];
for (i=0; i<totalCCs; i++)
{
// 3 bytes per CC
byteArray.push(expGolombDecoder.readUByte());
byteArray.push(expGolombDecoder.readUByte());
byteArray.push(expGolombDecoder.readUByte());
}
this._txtTrack.samples.push({type: 3, pts: pes.pts, bytes: byteArray});
}
}
}
}
}
break;
//SPS
case 7:
push = true;
if(debug) {
debugString += 'SPS ';
}
if(!track.sps) {
expGolombDecoder = new ExpGolomb(unit.data);
var config = expGolombDecoder.readSPS();
track.width = config.width;
track.height = config.height;
track.sps = [unit.data];
track.timescale = this.remuxer.timescale;
track.duration = this.remuxer.timescale * this._duration;
var codecarray = unit.data.subarray(1, 4);
var codecstring = 'avc1.';
for (i = 0; i < 3; i++) {
var h = codecarray[i].toString(16);
if (h.length < 2) {
h = '0' + h;
}
codecstring += h;
}
track.codec = codecstring;
}
break;
//PPS
case 8:
push = true;
if(debug) {
debugString += 'PPS ';
}
if (!track.pps) {
track.pps = [unit.data];
}
break;
case 9:
push = false;
if(debug) {
debugString += 'AUD ';
}
break;
default:
push = false;
debugString += 'unknown NAL ' + unit.type + ' ';
break;
}
if(push) {
units2.push(unit);
length+=unit.data.byteLength;
}
});
if(debug || debugString.length) {
logger.log(debugString);
}
//build sample from PES
// Annex B to MP4 conversion to be done
if (units2.length) {
// only push AVC sample if keyframe already found. browsers expect a keyframe at first to start decoding
if (key === true || track.sps ) {
avcSample = {units: { units : units2, length : length}, pts: pes.pts, dts: pes.dts, key: key};
samples.push(avcSample);
track.len += length;
track.nbNalu += units2.length;
}
}
}
_parseAVCNALu(array) {
var i = 0, len = array.byteLength, value, overflow, state = 0;
var units = [], unit, unitType, lastUnitStart, lastUnitType;
//logger.log('PES:' + Hex.hexDump(array));
while (i < len) {
value = array[i++];
// finding 3 or 4-byte start codes (00 00 01 OR 00 00 00 01)
switch (state) {
case 0:
if (value === 0) {
state = 1;
}
break;
case 1:
if( value === 0) {
state = 2;
} else {
state = 0;
}
break;
case 2:
case 3:
if( value === 0) {
state = 3;
} else if (value === 1 && i < len) {
unitType = array[i] & 0x1f;
//logger.log('find NALU @ offset:' + i + ',type:' + unitType);
if (lastUnitStart) {
unit = {data: array.subarray(lastUnitStart, i - state - 1), type: lastUnitType};
//logger.log('pushing NALU, type/size:' + unit.type + '/' + unit.data.byteLength);
units.push(unit);
} else {
// If NAL units are not starting right at the beginning of the PES packet, push preceding data into previous NAL unit.
overflow = i - state - 1;
if (overflow) {
var track = this._avcTrack,
samples = track.samples;
//logger.log('first NALU found with overflow:' + overflow);
if (samples.length) {
var lastavcSample = samples[samples.length - 1],
lastUnits = lastavcSample.units.units,
lastUnit = lastUnits[lastUnits.length - 1],
tmp = new Uint8Array(lastUnit.data.byteLength + overflow);
tmp.set(lastUnit.data, 0);
tmp.set(array.subarray(0, overflow), lastUnit.data.byteLength);
lastUnit.data = tmp;
lastavcSample.units.length += overflow;
track.len += overflow;
}
}
}
lastUnitStart = i;
lastUnitType = unitType;
state = 0;
} else {
state = 0;
}
break;
default:
break;
}
}
if (lastUnitStart) {
unit = {data: array.subarray(lastUnitStart, len), type: lastUnitType};
units.push(unit);
//logger.log('pushing NALU, type/size:' + unit.type + '/' + unit.data.byteLength);
}
return units;
}
_parseAACPES(pes) {
var track = this._aacTrack,
data = pes.data,
pts = pes.pts,
startOffset = 0,
duration = this._duration,
audioCodec = this.audioCodec,
aacOverFlow = this.aacOverFlow,
lastAacPTS = this.lastAacPTS,
config, frameLength, frameDuration, frameIndex, offset, headerLength, stamp, len, aacSample;
if (aacOverFlow) {
var tmp = new Uint8Array(aacOverFlow.byteLength + data.byteLength);
tmp.set(aacOverFlow, 0);
tmp.set(data, aacOverFlow.byteLength);
//logger.log(`AAC: append overflowing ${aacOverFlow.byteLength} bytes to beginning of new PES`);
data = tmp;
}
// look for ADTS header (0xFFFx)
for (offset = startOffset, len = data.length; offset < len - 1; offset++) {
if ((data[offset] === 0xff) && (data[offset+1] & 0xf0) === 0xf0) {
break;
}
}
// if ADTS header does not start straight from the beginning of the PES payload, raise an error
if (offset) {
var reason, fatal;
if (offset < len - 1) {
reason = `AAC PES did not start with ADTS header,offset:${offset}`;
fatal = false;
} else {
reason = 'no ADTS header found in AAC PES';
fatal = true;
}
this.observer.trigger(Event.ERROR, {type: ErrorTypes.MEDIA_ERROR, details: ErrorDetails.FRAG_PARSING_ERROR, fatal: fatal, reason: reason});
if (fatal) {
return;
}
}
if (!track.audiosamplerate) {
config = ADTS.getAudioConfig(this.observer,data, offset, audioCodec);
track.config = config.config;
track.audiosamplerate = config.samplerate;
track.channelCount = config.channelCount;
track.codec = config.codec;
track.timescale = config.samplerate;
track.duration = config.samplerate * duration;
logger.log(`parsed codec:${track.codec},rate:${config.samplerate},nb channel:${config.channelCount}`);
}
frameIndex = 0;
frameDuration = 1024 * 90000 / track.audiosamplerate;
// if last AAC frame is overflowing, we should ensure timestamps are contiguous:
// first sample PTS should be equal to last sample PTS + frameDuration
if(aacOverFlow && lastAacPTS) {
var newPTS = lastAacPTS+frameDuration;
if(Math.abs(newPTS-pts) > 1) {
logger.log(`AAC: align PTS for overlapping frames by ${Math.round((newPTS-pts)/90)}`);
pts=newPTS;
}
}
while ((offset + 5) < len) {
// The protection skip bit tells us if we have 2 bytes of CRC data at the end of the ADTS header
headerLength = (!!(data[offset + 1] & 0x01) ? 7 : 9);
// retrieve frame size
frameLength = ((data[offset + 3] & 0x03) << 11) |
(data[offset + 4] << 3) |
((data[offset + 5] & 0xE0) >>> 5);
frameLength -= headerLength;
//stamp = pes.pts;
if ((frameLength > 0) && ((offset + headerLength + frameLength) <= len)) {
stamp = pts + frameIndex * frameDuration;
//logger.log(`AAC frame, offset/length/total/pts:${offset+headerLength}/${frameLength}/${data.byteLength}/${(stamp/90).toFixed(0)}`);
aacSample = {unit: data.subarray(offset + headerLength, offset + headerLength + frameLength), pts: stamp, dts: stamp};
track.samples.push(aacSample);
track.len += frameLength;
offset += frameLength + headerLength;
frameIndex++;
// look for ADTS header (0xFFFx)
for ( ; offset < (len - 1); offset++) {
if ((data[offset] === 0xff) && ((data[offset + 1] & 0xf0) === 0xf0)) {
break;
}
}
} else {
break;
}
}
if (offset < len) {
aacOverFlow = data.subarray(offset, len);
//logger.log(`AAC: overflow detected:${len-offset}`);
} else {
aacOverFlow = null;
}
this.aacOverFlow = aacOverFlow;
this.lastAacPTS = stamp;
}
_parseID3PES(pes) {
this._id3Track.samples.push(pes);
}
}
export default TSDemuxer;