Attempt to adjust m2ts sample times to fix gaps in appended media

Resolves aspects of #5631

src/remux/mp4-remuxer.ts

@@ -461,8 +461,17 @@ export default class MP4Remuxer implements Remuxer {
  const cts =
  inputSamples[0].pts -
  normalizePts(inputSamples[0].dts, inputSamples[0].pts);
- // if not contiguous, let's use target timeOffset
- nextAvcDts = pts - cts;
+ if (
+ chromeVersion &&
+ nextAvcDts !== null &&
+ Math.abs(pts - cts - nextAvcDts) < 15000
+ ) {
+ // treat as contigous to adjust samples that would otherwise produce video buffer gaps in Chrome
+ contiguous = true;
+ } else {
+ // if not contiguous, let's use target timeOffset
+ nextAvcDts = pts - cts;
+ }
  }
 
  // PTS is coded on 33bits, and can loop from -2^32 to 2^32
@@ -575,10 +584,12 @@ export default class MP4Remuxer implements Remuxer {
  sample.length = sampleLen;
 
  // ensure sample monotonic DTS
- if (dtsStep < sample.dts) {
+ if (sample.dts < dtsStep) {
+ sample.dts = dtsStep;
+ dtsStep += (averageSampleDuration / 4) | 0 || 1;
+ } else {
  dtsStep = sample.dts;
  }
- sample.dts = sample.dts < dtsStep ? dtsStep++ : sample.dts;
 
  minPTS = Math.min(sample.pts, minPTS);
  maxPTS = Math.max(sample.pts, maxPTS);