[FFmpeg-trac] #4536(ffmpeg:new): mkv audio reencoding leads to nonuniform video timecodes

[FFmpeg]

#4536: mkv audio reencoding leads to nonuniform video timecodes
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             Reporter:  sneaker     |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  ffmpeg
              Version:  git-master  |               Resolution:
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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Comment (by sneaker):

 You are kind of right, I didn't look close enough. Happens on 3 occasions:
 49 - 0 = 49
 167 - 132 = 32
 216 - 167 = 49
 Then again, the sample is short and there is a general shift of the
 timecodes. (didn't test if async)

 I also suspected special Opus handling at first but it happens with other
 formats as well (but not with pcm). Interestingly, it also only happens on
 those 3 points (+the general skew) but each one with different timecodes:
 ac3:
 {{{
 # timecode format v2
 0
 48
 89
 131
 167
 215
 256
 298
 340
 381
 423
 465
 506
 ...
 }}}

 mp3:
 {{{
 # timecode format v2
 0
 67
 108
 150
 167
 234
 275
 317
 359
 400
 442
 484
 525
 }}}

 vorbis:
 {{{
 # timecode format v2
 0
 45
 86
 128
 167
 212
 253
 295
 337
 378
 420
 462
 503
 ...
 }}}

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Ticket URL: <https://trac.ffmpeg.org/ticket/4536#comment:2>
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