[FFmpeg-trac] #3853(undetermined:new): silence in front of generated audio mpegts

FFmpeg trac at avcodec.org
Thu Aug 14 18:26:17 CEST 2014

#3853: silence in front of generated audio mpegts
             Reporter:  mpapp        |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
 Let a.ts be an mpegts with aac encoded audio only.

 /ffmpeg/ffmpeg -i a.ts -acodec aac -strict -2 -loglevel debug audio.ts

 Input #0, aac, from 'a.ts': Duration: 00:00:05.06, bitrate: 126 kb/s
 Stream #0:0: Audio: aac, 44100 Hz, stereo, fltp, 126 kb/s

 if I convert a.ts and audio.ts into .wav I will get two wav files, one of
 them has silence in front of it. I used audacity to determine that about
 0.031s audio.ts will have some silence.
 I can see that a.ts has 215 audio frames and audio.ts 216.

 Any explanations why is silence added to ts? As far as I can see it could
 be a bug.
 Summary: the command at top introduces one extra frame to the start of aac
 stream, making aac longer as it should.

Ticket URL: <https://trac.ffmpeg.org/ticket/3853>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker

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