ffmpeg.exe -acodec pcm_mulaw -i camera.stream.flv -vn -ar 44100 -ac 2 -ab 192 -f mp3 test.mp3

FFmpeg version SVN-r18639, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --enable-memalign-hack --enable-postproc --enable-gpl --enable-
libfaac --enable-libfaad --enable-libgsm --enable-libmp3lame --enable-libvorbis
--enable-libtheora --enable-libx264 --enable-libxvid --disable-ffserver --enable
-avisynth --enable-pthreads
  libavutil     50. 3. 0 / 50. 3. 0
  libavcodec    52.27. 0 / 52.27. 0
  libavformat   52.32. 0 / 52.32. 0
  libavdevice   52. 2. 0 / 52. 2. 0
  libswscale     0. 7. 1 /  0. 7. 1
  libpostproc   51. 2. 0 / 51. 2. 0
  built on Apr 21 2009 13:44:38, gcc: 4.2.4 (TDM-1 for MinGW)
[flv @ 0x148ac00]skipping flv packet: type 18, size 76, flags 0
[flv @ 0x148ac00]skipping flv packet: type 18, size 3430, flags 0
[flv @ 0x148ac00]Unsupported audio codec (8)

Seems stream 0 codec frame rate differs from container frame rate: 2000.00 (2000
/1) -> 30.00 (30/1)
Input #0, flv, from 'camera.stream.flv':
  Duration: 00:00:13.93, start: 0.000000, bitrate: N/A
    Stream #0.0: Video: h264, yuv420p, 1280x720, 30 tbr, 1k tbn, 2k tbc
    Stream #0.1: Audio: pcm_mulaw, 5512 Hz, mono, s16, 44 kb/s
WARNING: The bitrate parameter is set too low. It takes bits/s as argument, not
kbits/s
Output #0, mp3, to 'test.mp3':
    Stream #0.0: Audio: libmp3lame, 44100 Hz, stereo, s16, 0 kb/s
Stream mapping:
  Stream #0.1 -> #0.0
Press [q] to stop encoding
size=     319kB time=20.43 bitrate= 128.0kbits/s
video:0kB audio:319kB global headers:0kB muxing overhead 0.009791%