[FFmpeg-trac] #933(FFmpeg:new): A/V desynch when transcoding A/V files with timestamps non starting from 0 with -copyts

[FFmpeg]

#933: A/V desynch when transcoding A/V files with timestamps non starting from 0
with -copyts
-------------------------------------+-------------------------------------
               Reporter:  saste      |                  Owner:
                   Type:  defect     |                 Status:  new
               Priority:  normal     |              Component:  FFmpeg
                Version:  git-       |               Keywords:  timestamp
  master                             |  desynch mpegts
             Blocked By:             |               Blocking:
Reproduced by developer:  1          |  Analyzed by developer:  0
-------------------------------------+-------------------------------------
 Using the command:
 {{{
 ffmpeg -vsync 0 -copyts -i columbia-intro.ts -acodec libfaac -y columbia-
 intro.out.ts
 }}}

 (same without -vsync) the A/V streams in the output file result desynched,
 and will result in the video being unplayable. This seems due to the first
 audio packet timestamp information not being correctly propagated to the
 encoder (and to the muxer), and being set to 0, so that ffmpeg will fill
 the first part of the file with audio packets, and the probe will fail
 since ffmpeg can't detect video frames in the probed initial part of the
 file.

 Same result in case I use the -copyts with no -vsync. If the output file
 only contains video (e.g. if the -an switch is used) the output file seems
 to be correctly generated (playable and with correct timestamp
 information).

 I'm attaching a sample file and log obtained by adding debugging print in
 ffmpeg.c.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/933>
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