1
0
Fork 0
mirror of https://github.com/jellyfin/jellyfin-web synced 2025-03-30 19:56:21 +00:00

update hls playback

This commit is contained in:
Luke Pulverenti 2016-04-20 14:51:47 -04:00
parent 7919706532
commit 396b125d66
27 changed files with 438 additions and 728 deletions

View file

@ -132,164 +132,135 @@ class MP4Remuxer {
}
remuxVideo(track, timeOffset, contiguous) {
var offset = 8,
var view,
offset = 8,
pesTimeScale = this.PES_TIMESCALE,
pes2mp4ScaleFactor = this.PES2MP4SCALEFACTOR,
mp4SampleDuration,
avcSample,
mp4Sample,
mp4SampleLength,
unit,
mdat, moof,
firstPTS, firstDTS,
nextDTS,
lastPTS, lastDTS,
inputSamples = track.samples,
outputSamples = [];
// PTS is coded on 33bits, and can loop from -2^32 to 2^32
// PTSNormalize will make PTS/DTS value monotonic, we use last known DTS value as reference value
let nextAvcDts;
if (contiguous) {
// if parsed fragment is contiguous with last one, let's use last DTS value as reference
nextAvcDts = this.nextAvcDts;
} else {
// if not contiguous, let's use target timeOffset
nextAvcDts = timeOffset*pesTimeScale;
}
// compute first DTS and last DTS, normalize them against reference value
let sample = inputSamples[0];
firstDTS = Math.max(this._PTSNormalize(sample.dts,nextAvcDts) - this._initDTS,0);
firstPTS = Math.max(this._PTSNormalize(sample.pts,nextAvcDts) - this._initDTS,0);
// check timestamp continuity accross consecutive fragments (this is to remove inter-fragment gap/hole)
let delta = Math.round((firstDTS - nextAvcDts) / 90);
// if fragment are contiguous, or if there is a huge delta (more than 10s) between expected PTS and sample PTS
if (contiguous || Math.abs(delta) > 10000) {
if (delta) {
if (delta > 1) {
logger.log(`AVC:${delta} ms hole between fragments detected,filling it`);
} else if (delta < -1) {
logger.log(`AVC:${(-delta)} ms overlapping between fragments detected`);
}
// remove hole/gap : set DTS to next expected DTS
firstDTS = nextAvcDts;
inputSamples[0].dts = firstDTS + this._initDTS;
// offset PTS as well, ensure that PTS is smaller or equal than new DTS
firstPTS = Math.max(firstPTS - delta, nextAvcDts);
inputSamples[0].pts = firstPTS + this._initDTS;
logger.log(`Video/PTS/DTS adjusted: ${firstPTS}/${firstDTS},delta:${delta}`);
}
}
nextDTS = firstDTS;
// compute lastPTS/lastDTS
sample = inputSamples[inputSamples.length-1];
lastDTS = Math.max(this._PTSNormalize(sample.dts,nextAvcDts) - this._initDTS,0);
lastPTS = Math.max(this._PTSNormalize(sample.pts,nextAvcDts) - this._initDTS,0);
lastPTS = Math.max(lastPTS, lastDTS);
let vendor = navigator.vendor, userAgent = navigator.userAgent,
isSafari = vendor && vendor.indexOf('Apple') > -1 && userAgent && !userAgent.match('CriOS');
// on Safari let's signal the same sample duration for all samples
// sample duration (as expected by trun MP4 boxes), should be the delta between sample DTS
// set this constant duration as being the avg delta between consecutive DTS.
if (isSafari) {
mp4SampleDuration = Math.round((lastDTS-firstDTS)/(pes2mp4ScaleFactor*(inputSamples.length-1)));
}
// normalize all PTS/DTS now ...
for (let i = 0; i < inputSamples.length; i++) {
let sample = inputSamples[i];
if (isSafari) {
// sample DTS is computed using a constant decoding offset (mp4SampleDuration) between samples
sample.dts = firstDTS + i*pes2mp4ScaleFactor*mp4SampleDuration;
} else {
// ensure sample monotonic DTS
sample.dts = Math.max(this._PTSNormalize(sample.dts, nextAvcDts) - this._initDTS,firstDTS);
// ensure dts is a multiple of scale factor to avoid rounding issues
sample.dts = Math.round(sample.dts/pes2mp4ScaleFactor)*pes2mp4ScaleFactor;
}
// we normalize PTS against nextAvcDts, we also substract initDTS (some streams don't start @ PTS O)
// and we ensure that computed value is greater or equal than sample DTS
sample.pts = Math.max(this._PTSNormalize(sample.pts,nextAvcDts) - this._initDTS, sample.dts);
// ensure pts is a multiple of scale factor to avoid rounding issues
sample.pts = Math.round(sample.pts/pes2mp4ScaleFactor)*pes2mp4ScaleFactor;
}
firstPTS, firstDTS, lastDTS,
pts, dts, ptsnorm, dtsnorm,
flags,
samples = [];
/* concatenate the video data and construct the mdat in place
(need 8 more bytes to fill length and mpdat type) */
mdat = new Uint8Array(track.len + (4 * track.nbNalu) + 8);
let view = new DataView(mdat.buffer);
view = new DataView(mdat.buffer);
view.setUint32(0, mdat.byteLength);
mdat.set(MP4.types.mdat, 4);
for (let i = 0; i < inputSamples.length; i++) {
let avcSample = inputSamples[i],
mp4SampleLength = 0,
compositionTimeOffset;
while (track.samples.length) {
avcSample = track.samples.shift();
mp4SampleLength = 0;
// convert NALU bitstream to MP4 format (prepend NALU with size field)
while (avcSample.units.units.length) {
let unit = avcSample.units.units.shift();
unit = avcSample.units.units.shift();
view.setUint32(offset, unit.data.byteLength);
offset += 4;
mdat.set(unit.data, offset);
offset += unit.data.byteLength;
mp4SampleLength += 4 + unit.data.byteLength;
}
if(!isSafari) {
// expected sample duration is the Decoding Timestamp diff of consecutive samples
if (i < inputSamples.length - 1) {
mp4SampleDuration = inputSamples[i+1].dts - avcSample.dts;
} else {
// last sample duration is same than previous one
mp4SampleDuration = avcSample.dts - inputSamples[i-1].dts;
pts = avcSample.pts - this._initDTS;
dts = avcSample.dts - this._initDTS;
// ensure DTS is not bigger than PTS
dts = Math.min(pts,dts);
//logger.log(`Video/PTS/DTS:${Math.round(pts/90)}/${Math.round(dts/90)}`);
// if not first AVC sample of video track, normalize PTS/DTS with previous sample value
// and ensure that sample duration is positive
if (lastDTS !== undefined) {
ptsnorm = this._PTSNormalize(pts, lastDTS);
dtsnorm = this._PTSNormalize(dts, lastDTS);
var sampleDuration = (dtsnorm - lastDTS) / pes2mp4ScaleFactor;
if (sampleDuration <= 0) {
logger.log(`invalid sample duration at PTS/DTS: ${avcSample.pts}/${avcSample.dts}:${sampleDuration}`);
sampleDuration = 1;
}
mp4SampleDuration /= pes2mp4ScaleFactor;
compositionTimeOffset = Math.round((avcSample.pts - avcSample.dts) / pes2mp4ScaleFactor);
mp4Sample.duration = sampleDuration;
} else {
compositionTimeOffset = Math.max(0,mp4SampleDuration*Math.round((avcSample.pts - avcSample.dts)/(pes2mp4ScaleFactor*mp4SampleDuration)));
let nextAvcDts, delta;
if (contiguous) {
nextAvcDts = this.nextAvcDts;
} else {
nextAvcDts = timeOffset*pesTimeScale;
}
// first AVC sample of video track, normalize PTS/DTS
ptsnorm = this._PTSNormalize(pts, nextAvcDts);
dtsnorm = this._PTSNormalize(dts, nextAvcDts);
delta = Math.round((dtsnorm - nextAvcDts) / 90);
// if fragment are contiguous, detect hole/overlapping between fragments
if (contiguous) {
if (delta) {
if (delta > 1) {
logger.log(`AVC:${delta} ms hole between fragments detected,filling it`);
} else if (delta < -1) {
logger.log(`AVC:${(-delta)} ms overlapping between fragments detected`);
}
// set DTS to next DTS
dtsnorm = nextAvcDts;
// offset PTS as well, ensure that PTS is smaller or equal than new DTS
ptsnorm = Math.max(ptsnorm - delta, dtsnorm);
logger.log(`Video/PTS/DTS adjusted: ${ptsnorm}/${dtsnorm},delta:${delta}`);
}
}
// remember first PTS of our avcSamples, ensure value is positive
firstPTS = Math.max(0, ptsnorm);
firstDTS = Math.max(0, dtsnorm);
}
//console.log('PTS/DTS/initDTS/normPTS/normDTS/relative PTS : ${avcSample.pts}/${avcSample.dts}/${this._initDTS}/${ptsnorm}/${dtsnorm}/${(avcSample.pts/4294967296).toFixed(3)}');
outputSamples.push({
mp4Sample = {
size: mp4SampleLength,
// constant duration
duration: mp4SampleDuration,
cts: compositionTimeOffset,
duration: 0,
cts: (ptsnorm - dtsnorm) / pes2mp4ScaleFactor,
flags: {
isLeading: 0,
isDependedOn: 0,
hasRedundancy: 0,
degradPrio: 0,
dependsOn : avcSample.key ? 2 : 1,
isNonSync : avcSample.key ? 0 : 1
degradPrio: 0
}
});
};
flags = mp4Sample.flags;
if (avcSample.key === true) {
// the current sample is a key frame
flags.dependsOn = 2;
flags.isNonSync = 0;
} else {
flags.dependsOn = 1;
flags.isNonSync = 1;
}
samples.push(mp4Sample);
lastDTS = dtsnorm;
}
// next AVC sample DTS should be equal to last sample DTS + last sample duration (in PES timescale)
this.nextAvcDts = lastDTS + mp4SampleDuration*pes2mp4ScaleFactor;
var lastSampleDuration = 0;
if (samples.length >= 2) {
lastSampleDuration = samples[samples.length - 2].duration;
mp4Sample.duration = lastSampleDuration;
}
// next AVC sample DTS should be equal to last sample DTS + last sample duration
this.nextAvcDts = dtsnorm + lastSampleDuration * pes2mp4ScaleFactor;
track.len = 0;
track.nbNalu = 0;
if(outputSamples.length && navigator.userAgent.toLowerCase().indexOf('chrome') > -1) {
let flags = outputSamples[0].flags;
if(samples.length && navigator.userAgent.toLowerCase().indexOf('chrome') > -1) {
flags = samples[0].flags;
// chrome workaround, mark first sample as being a Random Access Point to avoid sourcebuffer append issue
// https://code.google.com/p/chromium/issues/detail?id=229412
flags.dependsOn = 2;
flags.isNonSync = 0;
}
track.samples = outputSamples;
track.samples = samples;
moof = MP4.moof(track.sequenceNumber++, firstDTS / pes2mp4ScaleFactor, track);
track.samples = [];
this.observer.trigger(Event.FRAG_PARSING_DATA, {
data1: moof,
data2: mdat,
startPTS: firstPTS / pesTimeScale,
endPTS: (lastPTS + pes2mp4ScaleFactor * mp4SampleDuration) / pesTimeScale,
endPTS: (ptsnorm + pes2mp4ScaleFactor * lastSampleDuration) / pesTimeScale,
startDTS: firstDTS / pesTimeScale,
endDTS: this.nextAvcDts / pesTimeScale,
type: 'video',
nb: outputSamples.length
nb: samples.length
});
}
@ -328,7 +299,7 @@ class MP4Remuxer {
mp4Sample.duration = (dtsnorm - lastDTS) / pes2mp4ScaleFactor;
if(Math.abs(mp4Sample.duration - expectedSampleDuration) > expectedSampleDuration/10) {
// more than 10% diff between sample duration and expectedSampleDuration .... lets log that
logger.trace(`invalid AAC sample duration at PTS ${Math.round(pts/90)},should be 1024,found :${Math.round(mp4Sample.duration*track.audiosamplerate/track.timescale)}`);
logger.log(`invalid AAC sample duration at PTS ${Math.round(pts/90)},should be 1024,found :${Math.round(mp4Sample.duration*track.audiosamplerate/track.timescale)}`);
}
// always adjust sample duration to avoid av sync issue
mp4Sample.duration = expectedSampleDuration;
@ -343,20 +314,20 @@ class MP4Remuxer {
ptsnorm = this._PTSNormalize(pts, nextAacPts);
dtsnorm = this._PTSNormalize(dts, nextAacPts);
delta = Math.round(1000 * (ptsnorm - nextAacPts) / pesTimeScale);
// if fragment are contiguous, or if there is a huge delta (more than 10s) between expected PTS and sample PTS
if (contiguous || Math.abs(delta) > 10000) {
// if fragment are contiguous, detect hole/overlapping between fragments
if (contiguous) {
// log delta
if (delta) {
if (delta > 0) {
logger.log(`${delta} ms hole between AAC samples detected,filling it`);
// if we have frame overlap, overlapping for more than half a frame duraion
// if we have frame overlap, overlapping for more than half a frame duration
} else if (delta < -12) {
// drop overlapping audio frames... browser will deal with it
logger.log(`${(-delta)} ms overlapping between AAC samples detected, drop frame`);
track.len -= unit.byteLength;
continue;
}
// set PTS/DTS to expected PTS/DTS
// set PTS/DTS to next PTS/DTS
ptsnorm = dtsnorm = nextAacPts;
}
}