Attached file contains ~13 seconds of audio, playable with vlc and mplayer -demuxer mov, ffmpeg only decodes video.
$ ffmpeg -i noaudio.mp4 out.wav
ffmpeg version N-33192-gfe70c1f, Copyright (c) 2000-2011 the FFmpeg developers
built on Oct 1 2011 12:36:37 with gcc 4.3.2 [gcc-4_3-branch revision 141291]
configuration: --enable-libopenjpeg
libavutil 51. 18. 0 / 51. 18. 0
libavcodec 53. 19. 0 / 53. 19. 0
libavformat 53. 13. 0 / 53. 13. 0
libavdevice 53. 4. 0 / 53. 4. 0
libavfilter 2. 43. 6 / 2. 43. 6
libswscale 2. 1. 0 / 2. 1. 0
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x8d3faa0] multiple edit list entries, a/v desync might occur, patch welcome
Last message repeated 2 times
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x8d3faa0] stream 1, missing mandatory atoms, broken header
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x8d3faa0] multiple edit list entries, a/v desync might occur, patch welcome
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x8d3faa0] stream 3, missing mandatory atoms, broken header
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x8d3faa0] max_analyze_duration 5000000 reached at 5020000
Seems stream 0 codec frame rate differs from container frame rate: 600.00 (600/1) -> 150.00 (150/1)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'noaudio.mp4':
Metadata:
major_brand : 3gp5
minor_version : 256
compatible_brands: 3gp53gp4isom
creation_time : 2011-09-29 17:43:06
Duration: 00:00:59.36, start: 0.000000, bitrate: 206 kb/s
Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 864x488, 920 kb/s, 20.01 fps, 150 tbr, 300 tbn, 600 tbc
Metadata:
creation_time : 1945-09-21 14:05:41
Stream #0:1(eng): Data: none (stts / 0x73747473)
Metadata:
creation_time : 1945-09-21 14:05:41
Stream #0:2(eng): Audio: pcm_mulaw (ulaw / 0x77616C75), 8000 Hz, 1 channels, s16, 64 kb/s
Metadata:
creation_time : 1945-09-21 14:05:41
Stream #0:3(eng): Data: none (stts / 0x73747473)
Metadata:
creation_time : 1945-09-21 14:05:41
Output #0, wav, to 'out.wav':
Metadata:
major_brand : 3gp5
minor_version : 256
compatible_brands: 3gp53gp4isom
creation_time : 2011-09-29 17:43:06
encoder : Lavf53.13.0
Stream #0:0(eng): Audio: pcm_s16le ([1][0][0][0] / 0x0001), 8000 Hz, 1 channels, s16, 128 kb/s
Metadata:
creation_time : 1945-09-21 14:05:41
Stream mapping:
Stream #0.2 -> #0.0 (pcm_mulaw -> pcm_s16le)
Press [q] to stop, [?] for help
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x8d3faa0] stream 0, offset 0x177632: partial file
size= 0kB time=00:00:00.00 bitrate= 0.0kbits/s
video:0kB audio:0kB global headers:0kB muxing overhead inf%
