ffmpeg -acodec pcm_mulaw -i camera.stream.flv -vn -ar 44100 -ac 1 -ab
 192 -f mp3 test.mp3rm test.mp3


root@ubuntu:~# rm test.mp3 ffmpeg -acodec pcm_mulaw -i camera.stream.flv -vn -ar 44100 -ac 1 -ab
 192 -f mp3 test.mp3
ffmpeg version 0.10.2.git-8274b21 Copyright (c) 2000-2012 the FFmpeg developers
  built on Apr 12 2012 15:47:39 with gcc 4.5.2
  configuration: --enable-gpl --enable-shared --enable-swscale --enable-pthreads --enable-libdc1394 --enable-libfaac --enable-libgsm --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --disable-debug --enable-nonfree
  libavutil      51. 46.100 / 51. 46.100
  libavcodec     54. 14.101 / 54. 14.101
  libavformat    54.  3.100 / 54.  3.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 67.101 /  2. 67.101
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0. 11.100 /  0. 11.100
  libpostproc    52.  0.100 / 52.  0.100
[pcm_mulaw @ 0x1626ba0] PCM channels out of bounds
[flv @ 0x1620120] Unsupported audio codec (8)
    Last message repeated 1 times
    Last message repeated 2 times
    Last message repeated 3 times
    Last message repeated 4 times
    Last message repeated 5 times
    Last message repeated 6 times
    Last message repeated 7 times
    Last message repeated 8 times
    Last message repeated 9 times
    Last message repeated 10 times
    Last message repeated 11 times
    Last message repeated 12 times
    Last message repeated 12 times
Input #0, flv, from 'camera.stream.flv':
  Metadata:
    creationdate    : Tue Apr 10 14:32:29
  Duration: 00:00:13.93, start: 0.000000, bitrate: 4268 kb/s
    Stream #0:0: Video: h264 (Baseline), yuv420p, 1280x720, 30 tbr, 1k tbn, 2k tbc
    Stream #0:1: Audio: pcm_mulaw, 5512 Hz, 1 channels, s16, 44 kb/s
The bitrate parameter is set too low. It takes bits/s as argument, not kbits/s
Guessed Channel Layout for  Input Stream #0.1 : mono
Output #0, mp3, to 'test.mp3':
  Metadata:
    creationdate    : Tue Apr 10 14:32:29
    TSSE            : Lavf54.3.100
    Stream #0:0: Audio: mp3, 44100 Hz, mono, s16, 0 kb/s
Stream mapping:
  Stream #0:1 -> #0:0 (pcm_mulaw -> libmp3lame)
Press [q] to stop, [?] for help
Multiple frames in a packet from stream 1
DTS 308, next:366700 st:1 invalid dropping
PTS 308, next:366700 invalid dropping st:1
[mp3 @ 0x1627de0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 43006 >= 35200
[mp3 @ 0x1627de0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 43006 >= 37551
[mp3 @ 0x1627de0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 43006 >= 39902
[mp3 @ 0x1627de0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 43006 >= 42253
[mp3 @ 0x1627de0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49306 >= 46782

-------------------------------

[mp3 @ 0x1627de0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 1268761 >= 1268590
size=     160kB time=00:00:14.28 bitrate=  91.7kbits/s

video:0kB audio:160kB global headers:0kB muxing overhead 0.143188%