[FFmpeg-trac] #4712(undetermined:new): shorten decoder is not lossless

[FFmpeg]

#4712: shorten decoder is not lossless
-------------------------------------+-------------------------------------
               Reporter:  ami_stuff  |                  Owner:
                   Type:  defect     |                 Status:  new
               Priority:  normal     |              Component:
                Version:             |  undetermined
  unspecified                        |               Keywords:
             Blocked By:             |               Blocking:
Reproduced by developer:  0          |  Analyzed by developer:  0
-------------------------------------+-------------------------------------
 it looks like the last frame of the audio is not decoded compared to the
 official decoder

 I did this:

 ffmpeg -i test.shn ffmpeg.wav

 shorten -x test.shn shorten.wav
 ffmpeg -i shorten.wav shorten_ff.wav

 and then compared "ffmpeg.wav" vs "shorten_ff.wav"

 in hex editor ("shorter_ff.wav" file is a bit longer)

 http://www.datafilehost.com/d/e5b57ea1

 {{{
 C:\>ffmpeg -i test.shn out.wav
 ffmpeg version N-73510-g033dc39 Copyright (c) 2000-2015 the FFmpeg
 developers
   built with gcc 4.9.2 (GCC)
   configuration: --enable-gpl --enable-version3 --disable-w32threads
 --enable-av
 isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls
 --enab
 le-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-
 libcaca --
 enable-libdcadec --enable-libfreetype --enable-libgme --enable-libgsm
 --enable-l
 ibilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb
 --enab
 le-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-
 librtmp --en
 able-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora
 --ena
 ble-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-
 amrwbenc
  --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp
 --enabl
 e-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma
 --ena
 ble-decklink --enable-zlib
   libavutil      54. 28.100 / 54. 28.100
   libavcodec     56. 47.100 / 56. 47.100
   libavformat    56. 40.100 / 56. 40.100
   libavdevice    56.  4.100 / 56.  4.100
   libavfilter     5. 21.100 /  5. 21.100
   libswscale      3.  1.101 /  3.  1.101
   libswresample   1.  2.100 /  1.  2.100
   libpostproc    53.  3.100 / 53.  3.100
 Guessed Channel Layout for  Input Stream #0.0 : stereo
 Input #0, shn, from 'test.shn':
   Duration: N/A, start: 0.000000, bitrate: N/A
     Stream #0:0: Audio: shorten, 44100 Hz, 2 channels, s16p
 Output #0, wav, to 'out.wav':
   Metadata:
     ISFT            : Lavf56.40.100
     Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz,
 stereo, s16
 , 1411 kb/s
     Metadata:
       encoder         : Lavc56.47.100 pcm_s16le
 Stream mapping:
   Stream #0:0 -> #0:0 (shorten (native) -> pcm_s16le (native))
 Press [q] to stop, [?] for help
 Multiple frames in a packet from stream 0
 size=    5170kB time=00:00:30.00 bitrate=1411.5kbits/s
 video:0kB audio:5170kB subtitle:0kB other streams:0kB global headers:0kB
 muxing
 overhead: 0.001473%
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4712>
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