[FFmpeg-trac] #1755(avformat:new): Audio becomes silent on some avi files. (This problem is reproduced during 1x play and seek)

FFmpeg trac at avcodec.org
Thu Sep 20 09:34:15 CEST 2012

#1755: Audio becomes silent on some avi files. (This problem is reproduced during
1x play and seek)
             Reporter:  Heesuk Jung  |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:  avformat     |                  Version:  0.11.1
             Keywords:  Grouped      |               Blocked By:
  Audio PTS                          |  Reproduced by developer:  1
             Blocking:               |
Analyzed by developer:  1            |
 Summary of the bug:

 Audio become silent before playback reach end of file.
 Video end at about 31 sec but audio stopped about 12 sec.

 I reviewed audio and video PTS information using ffprobe tool.
 Please refer the PTS plotting graph as below.
 (Notice! Recommend download of PTS plotting file because of Google docs
 excel inter-operability)
 * PTS plotting link :
 * Problematic file link :

 My Analysis of PTS
  - Video PTS is OK.
  - Audio PTS is NG.
   - Whole timeline of this media file is about 31 sec but audio pts has
 about 12 sec timeline.
   - Also values of Audio PTS are grouped as special pattern.
   - Simplified Audio PTS pattern : 0, 0, 0, 1, 1, 2, 2, ……. , N/3
   - Simplified Video PTS pattern : 0, 1, 2, …. , N

  -> The shape of audio PTS make 2 problem.
   1) Audio stop early. Because audio PTS by ffmpeg have 12 sec but real
 audio has 30 sec.
   2) Seek does not work after 12 sec.
    - My co-worker checked audio PTS information of problematic based on
 avidemux and Audio PTS is just OK.
    - And so I request that FFmpeg team inspect this problem.

 How to reproduce:
 % ffplay
 016_avi_mpeg4_sp[720 at 24fps]_aac[2ch_128kbps_44.1khz].avi[MV]_origin.avi

Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1755>
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