Comment 3 for bug 929178

Tried this command line instead:
/usr/bin/avconv -i /opt/canonical.com/qa-regression-testing/data/sound-file.wav -acodec ac3_fixed test.ac3
Got similar output:
avconv version 0.8-4:0.8-1ubuntu1, Copyright (c) 2000-2011 the Libav developers
  built on Jan 24 2012 07:15:53 with gcc 4.6.2
Input #0, wav, from '/opt/canonical.com/qa-regression-testing/data/sound-file.wav':
  Duration: 00:00:00.76, bitrate: 706 kb/s
    Stream #0.0: Audio: pcm_s16le, 44100 Hz, 1 channels, s16, 705 kb/s
[ac3_fixed @ 0x169b600] channel_layout not specified
[ac3_fixed @ 0x169b600] No channel layout specified. The encoder will guess the layout, but it might be incorrect.
[ac3_fixed @ 0x169b600] invalid bit rate
Output #0, ac3, to 'test.ac3':
    Stream #0.0: Audio: ac3, 44100 Hz, mono, s16, 200 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le -> ac3_fixed)
Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height

Also tried -acodec=ac3, and without -acodec specified, and all 3 with ffmpeg instead of avconv, and all cases failed.