[FFmpeg-trac] #4543(undetermined:new): Bad WAV output for an mkv file

[FFmpeg]

#4543: Bad WAV output for an mkv file
-------------------------------------+-------------------------------------
             Reporter:  birdie       |                     Type:  defect
               Status:  new          |                 Priority:  important
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug: when I try to export six channel audio from an MKV
 file the resulting file is broken (has a wrong length).

 ffmpeg version 2.6.2


 How to reproduce:
 {{{
 $ ffmpeg -i *mkv -vn output6ch.wav

 Input #0, matroska,webm, from 'testfile.mkv':
   Duration: 02:13:34.08, start: 0.000000, bitrate: 10924 kb/s

     Stream #0:0(eng): Video: h264 (High), yuv420p, 1920x800, SAR 1:1 DAR
 12:5, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
     Stream #0:1(eng): Audio: ac3, 48000 Hz, 5.1(side), fltp, 384 kb/s
 (default)
     Stream #0:2(eng): Audio: dts (DTS), 48000 Hz, 5.1(side), fltp, 1536
 kb/s
     Stream #0:3(dut): Subtitle: subrip (default)
     Metadata:
       title           : QoQ-Team
 Output #0, wav, to 'output6ch.wav':
   Metadata:
     ISFT            : Lavf56.25.101


 Stream mapping:
   Stream #0:1 -> #0:0 (ac3 (native) -> pcm_s16le (native))
 Press [q] to stop, [?] for help
 size= 4507920kB time=02:13:34.08 bitrate=4608.0kbits/s
 video:0kB audio:4507920kB subtitle:0kB other streams:0kB global
 headers:0kB muxing overhead: 0.000002%

 $ ffprobe *wav

 Input #0, wav, from 'output6ch.wav':
   Metadata:
     encoder         : Lavf56.25.101
   Duration: 00:09:17.54, bitrate: 66235 kb/s
     Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz,
 5.1(side), s16, 4608 kb/s

 $ ls -la *wav
 -rw-rw-r-- 1 user user 4616110182 May  8 15:46 output6ch.wav
 }}}

 As you can see the WAV file is heavily truncated.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4543>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker