[FFmpeg-trac] #9755(undetermined:open): gapless playback of *some* MP3 files destroyed in the end after -c copy (was: gapless playback of *some* MP3 files destroyed)

[FFmpeg]

#9755: gapless playback of *some* MP3 files destroyed in the end after -c copy
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             Reporter:  Christoph    |                    Owner:  (none)
  Anton Mitterer                     |
                 Type:  defect       |                   Status:  open
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  git-master   |               Resolution:
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
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Changes (by Balling):

 * summary:  gapless playback of *some* MP3 files destroyed =>
     gapless playback of *some* MP3 files destroyed in the end after -c
     copy

Comment:

 Nope, our bug. lame --decode decodes lame created file fine, but after -c
 copy file has extra samples in the end.

 Indeed, bad file has in lame --decode:

 skipping initial 1105 samples (encoder+decoder delay)
 skipping final 1152 samples (encoder padding-decoder delay)

 While good file has

 skipping initial 1105 samples (encoder+decoder delay)
 skipping final 1187 samples (encoder padding-decoder delay)

 and yes, -copy does corrupt this metadata, and yes the differnce in
 Audacity is 35 samples. Wow.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9755#comment:15>
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