~/tmp $ mplayer -ao pcm:output.wav input.amr
MPlayer 1.0rc2-4.2.3 (C) 2000-2007 MPlayer Team
CPU: Intel(R) Core(TM)2 Duo CPU     T9300  @ 2.50GHz (Family: 6, Model: 23, Stepping: 6)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing input.amr.
libavformat file format detected.
[lavf] Audio stream found, -aid 0
==========================================================================
Forced audio codec: mad
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 8000 Hz, 1 ch, s16le, 0.0 kbit/0.00% (ratio: 0->16000)
Selected audio codec: [ffamrnb] afm: ffmpeg (AMR Narrowband)
==========================================================================
Could not parse arguments at the position indicated below:
output.wav
^
Could not open/initialize audio device -> no sound.
Audio: no sound
Video: no video


Exiting... (End of file)