[FFmpeg-user] problem transcoding raw g729 to wav format

[Dave Horton]

>> No warnings here.

Interesting, I can replicate your results, but when I add some options for sample rate and encoding to the output, that is when I see errors:

MacBook-Pro-6:g729-testing dhorton$ ffmpeg  -y -f g729 -i caller.raw -ar 44100 -acodec pcm_s32le -f wav caller.wav

ffmpeg version N-87326-g3ffd3b7 Copyright (c) 2000-2017 the FFmpeg developers
  built with Apple LLVM version 7.3.0 (clang-703.0.29)
  configuration: --enable-gpl --enable-nonfree --enable-libopus --enable-libspeex --enable-libvpx --enable-libmp3lame --disable-optimizations --disable-stripping --extra-cflags='-DDEBUG -O0 -g'
  libavutil      55. 75.100 / 55. 75.100
  libavcodec     57.106.101 / 57.106.101
  libavformat    57. 82.100 / 57. 82.100
  libavdevice    57.  8.101 / 57.  8.101
  libavfilter     6.105.100 /  6.105.100
  libswscale      4.  7.103 /  4.  7.103
  libswresample   2.  8.100 /  2.  8.100
  libpostproc    54.  6.100 / 54.  6.100
[g729 @ 0x7fc3d4000000] Estimating duration from bitrate, this may be inaccurate
Guessed Channel Layout for Input Stream #0.0 : mono
Input #0, g729, from 'caller.raw':
  Duration: 00:00:20.48, start: 0.000000, bitrate: 8 kb/s
    Stream #0:0: Audio: g729, 8000 Hz, mono, s16
Stream mapping:
  Stream #0:0 -> #0:0 (g729 (native) -> pcm_s32le (native))
Press [q] to stop, [?] for help
Output #0, wav, to 'caller.wav':
  Metadata:
    ISFT            : Lavf57.82.100
    Stream #0:0: Audio: pcm_s32le ([1][0][0][0] / 0x0001), 44100 Hz, mono, s32, 1411 kb/s
    Metadata:
      encoder         : Lavc57.106.101 pcm_s32le
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -82; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -77; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -71; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -66; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -60; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -55; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -49; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -44; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -38; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -33; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -27; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -22; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -16; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -11; changing to 0. This may result in incorrect timestamps in the output file.
[wav @ 0x7fc3d4009e00] Non-monotonous DTS in output stream 0:0; previous: 0, current: -5; changing to 0. This may result in incorrect timestamps in the output file.
size=    3528kB time=00:00:00.26 bitrate=108706.8kbits/s speed=2.28x    
video:0kB audio:3528kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.002823%


** without output options, no errors


MacBook-Pro-6:g729-testing dhorton$ ffmpeg  -y -f g729 -i caller.raw -f wav caller.wav
ffmpeg version N-87326-g3ffd3b7 Copyright (c) 2000-2017 the FFmpeg developers
  built with Apple LLVM version 7.3.0 (clang-703.0.29)
  configuration: --enable-gpl --enable-nonfree --enable-libopus --enable-libspeex --enable-libvpx --enable-libmp3lame --disable-optimizations --disable-stripping --extra-cflags='-DDEBUG -O0 -g'
  libavutil      55. 75.100 / 55. 75.100
  libavcodec     57.106.101 / 57.106.101
  libavformat    57. 82.100 / 57. 82.100
  libavdevice    57.  8.101 / 57.  8.101
  libavfilter     6.105.100 /  6.105.100
  libswscale      4.  7.103 /  4.  7.103
  libswresample   2.  8.100 /  2.  8.100
  libpostproc    54.  6.100 / 54.  6.100
[g729 @ 0x7ff249810600] Estimating duration from bitrate, this may be inaccurate
Guessed Channel Layout for Input Stream #0.0 : mono
Input #0, g729, from 'caller.raw':
  Duration: 00:00:20.48, start: 0.000000, bitrate: 8 kb/s
    Stream #0:0: Audio: g729, 8000 Hz, mono, s16
Stream mapping:
  Stream #0:0 -> #0:0 (g729 (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, wav, to 'caller.wav':
  Metadata:
    ISFT            : Lavf57.82.100
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 8000 Hz, mono, s16, 128 kb/s
    Metadata:
      encoder         : Lavc57.106.101 pcm_s16le
size=     320kB time=00:00:00.26 bitrate=9862.0kbits/s speed=2.61x    
video:0kB audio:320kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.023804%