[FFmpeg-trac] #10270(ffmpeg:reopened): Random duration changes when transcoding ogg vorbis

[FFmpeg]

#10270: Random duration changes when transcoding ogg vorbis
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             Reporter:  Ace17       |                    Owner:  (none)
                 Type:  defect      |                   Status:  reopened
             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 Ace17):

 Also, here's another test I did on the produced soundX.ogg files.
 This time, I'm directly using vorbisfile (instead of ffprobe).

 {{{
 // ov_pcm_total.c
 // Compile with: gcc ov_pcm_total.c -lvorbisfile
 #include <stdio.h>
 #include "vorbis/vorbisfile.h"

 int main()
 {
   OggVorbis_File vf;

   if(ov_open(stdin, &vf, NULL, 0) < 0)
   {
       fprintf(stderr, "open failure\n");
       return 1;
   }

   printf("ov_pcm_total returns: % 8d samples ( encoded by %s )\n",
 ov_pcm_total(&vf,-1), ov_comment(&vf,-1)->vendor);
   ov_clear(&vf);
   return 0;
 }
 }}}

 Here's what I get:

 {{{
 sound1.ogg : ov_pcm_total returns:    44100 samples ( encoded by
 Lavf60.4.100 )
 sound2.ogg : ov_pcm_total returns:      380 samples ( encoded by
 Lavf60.4.100 )
 sound3.ogg : ov_pcm_total returns:    44160 samples ( encoded by
 Lavf60.4.100 )
 sound4.ogg : ov_pcm_total returns:    43712 samples ( encoded by
 Lavf60.4.100 )
 sound5.ogg : ov_pcm_total returns:    43712 samples ( encoded by
 Lavf60.4.100 )
 sound6.ogg : ov_pcm_total returns:    43712 samples ( encoded by
 Lavf60.4.100 )
 }}}

 I don't know what's causing this difference, but I definitely would have
 expected ov_pcm_total to return the same value for all files, here.

 Do you think I'm mistaken here ?

 Thanks in advance for your answer
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10270#comment:7>
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