root@rug-lap:/var/www/version2/videos# ffmpeg -i test.wmv -f flv -acodec mp3 -ab 64 -ac 1 test-stream2.flv 
FFmpeg version SVN-r9052, Copyright (c) 2000-2007 Fabrice Bellard, et al.
  configuration: --enable-libmp3lame
  libavutil version: 49.4.0
  libavcodec version: 51.40.4
  libavformat version: 51.12.1
  built on May 22 2007 01:01:25, gcc: 4.1.2 (Ubuntu 4.1.2-0ubuntu4)

Seems stream 1 codec frame rate differs from container frame rate: 1000.00 (1000/1) -> 30.00 (30/1)
Input #0, asf, from 'test.wmv':
  Duration: 00:09:11.4, start: 5.000000, bitrate: 350 kb/s
  Stream #0.0: Audio: wmav2, 32000 Hz, stereo, 32 kb/s
  Stream #0.1: Video: wmv3, yuv420p, 320x240, 308 kb/s, 30.00 fps(r)
File 'test-stream2.flv' already exists. Overwrite ? [y/N] y
Output #0, flv, to 'test-stream2.flv':
  Stream #0.0: Video: flv, yuv420p, 320x240, q=2-31, 200 kb/s, 30.00 fps(c)
  Stream #0.1: Audio: mp3, 32000 Hz, mono, 0 kb/s
Stream mapping:
  Stream #0.1 -> #0.0
  Stream #0.0 -> #0.1
[mp3 @ 0x848e488]flv doesnt support that sample rate, choose from (44100, 22050, 11025)
Could not write header for output file #0 (incorrect codec parameters ?)