[FFmpeg-user] No audio on .dav file converted to mp4

[Emanuel Piza]

Hi all,

I am converting .dav file (h264, security cam files) to mp4. I used the
following command, but ended up with a video that has no sound:

sudo ffmpeg -i input.dav -vf "crop=1500:800:460:280" -t 01:00 out37.mp4

I then tried extracting the sound separately in order to reunite later, but
had no success:

ffmpeg -i input.dav -vn -acodec copy output-audio.aac

Output:

ffmpeg version git-2016-05-20-e0706e9 Copyright (c) 2000-2016 the FFmpeg
developers

  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.1)

  configuration: --enable-gpl --enable-libfaac --enable-libmp3lame
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp
--enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264
--enable-nonfree --enable-version3

  libavutil      55. 24.100 / 55. 24.100

  libavcodec     57. 42.100 / 57. 42.100

  libavformat    57. 36.100 / 57. 36.100

  libavdevice    57.  0.101 / 57.  0.101

  libavfilter     6. 46.100 /  6. 46.100

  libswscale      4.  1.100 /  4.  1.100

  libswresample   2.  0.101 /  2.  0.101

  libpostproc    54.  0.100 / 54.  0.100

[h264 @ 0x2adf9e0] non-existing PPS 0 referenced

    Last message repeated 1 times

[h264 @ 0x2adf9e0] decode_slice_header error

[h264 @ 0x2adf9e0] no frame!

...

Input #0, h264, from 'input.dav':

  Duration: N/A, bitrate: N/A

    Stream #0:0: Video: h264 (High), yuv420p(tv, bt709), 2592x1520 [SAR 1:1
DAR 162:95], 25 fps, 15 tbr, 1200k tbn

Output #0, adts, to 'output-audio.aac':

Output file #0 does not contain any stream

Does anyone knows how could this be solved? Let me know if you need more
info.

Thanks in advance.

-- 
*Emanuel Piza*
email. ethales at gmail.com
cel. 19 99975 0044
twitter. @emanuelpiza