Bug#789254: This sample seems not to be processable by FFmpeg

[Petter Reinholdtsen]

[Peter Belkner]
> BS1770GAIN is based on FFmpeg. If a file is not processable by FFmpeg
> it is not processable by BS1770GAIN.
> 
> This particular sample file seems not to be processable by FFmpeg. Try
> e.g. the following command
> 
>   $ ffmpeg -i samples/20030213-cvs.mpeg -acodec copy -vcodec copy -y 20030213-cvs.mpeg

Thank you for looking into this, and it is good to have a way to detect
if the file should work with bs1770gain or not.

But are you sure the stuttering sound is due to the messages from ffmpeg
in this case?  I picked the MPEG file because it showed the problem and
was publicly available.  But as I mentioned, I see the problem with
other files too, and discovered it using a non-public DV file.  Here is
an example DV file from the set where I discovered the problem first:

  % ffmpeg -i makercon-50.dv -acodec copy -vcodec copy -y makercon-50-new.dv 
  ffmpeg version 2.7-1 Copyright (c) 2000-2015 the FFmpeg developers
    built with gcc 4.9.2 (Debian 4.9.2-20)
    configuration: --prefix=/usr --extra-version=1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --enable-shared --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libxvid --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzvbi --enable-libzmq --enable-frei0r --enable-libx264 --enable-libsoxr --enable-openal --enable-libopencv --enable-libx265
    libavutil      54. 27.100 / 54. 27.100
    libavcodec     56. 41.100 / 56. 41.100
    libavformat    56. 36.100 / 56. 36.100
    libavdevice    56.  4.100 / 56.  4.100
    libavfilter     5. 16.101 /  5. 16.101
    libavresample   2.  1.  0 /  2.  1.  0
    libswscale      3.  1.101 /  3.  1.101
    libswresample   1.  2.100 /  1.  2.100
    libpostproc    53.  3.100 / 53.  3.100
  [dv @ 0x1524ce0] Estimating duration from bitrate, this may be inaccurate
  Input #0, dv, from 'makercon-50.dv':
    Metadata:
      timecode        : 05:32:37:05
    Duration: 00:00:03.96, start: 0.000000, bitrate: 28800 kb/s
      Stream #0:0: Video: dvvideo, yuv420p, 720x576 [SAR 64:45 DAR 16:9], 28800 kb/s, 25 fps, 25 tbr, 25 tbn, 25 tbc
      Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
  Output #0, dv, to 'makercon-50-new.dv':
    Metadata:
      timecode        : 05:32:37:05
      encoder         : Lavf56.36.100
      Stream #0:0: Video: dvvideo, yuv420p, 720x576 [SAR 64:45 DAR 16:9], q=2-31, 28800 kb/s, 25 fps, 25 tbr, 25 tbn, 25 tbc
      Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, 1536 kb/s
  Stream mapping:
    Stream #0:0 -> #0:0 (copy)
    Stream #0:1 -> #0:1 (copy)
  Press [q] to stop, [?] for help
  makercon-50.dv: Input/output error
  frame=   99 fps=0.0 q=-1.0 Lsize=   13922kB time=00:00:03.96 bitrate=28800.0kbits/s    
  video:13922kB audio:742kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
  %

If I transcode it using bs1770gain, I end up with a file with stuttering
audio.

If you lack a DV file to test from, you can try yourself using the 1.1
GiB file available from
<URL: http://ftp.frikanalen.tv/media/625330/broadcast/DavidGallo_2007.dv >.

-- 
Happy hacking
Petter Reinholdtsen