Wma to Mp3 via mplayer fails on certain files...

[Daniel B. Thurman]

Is mplayer the only method to available (via script) to convert
Wma to Mp3?  It seems to work for most of my Wma files, but
not all of them.  All the failed files plays fine, none are video
capable, and yet I get these errors:
===============================================================================
# mplayer -ao pcm:file="test.wav" "text.wma"
# mplayer -af resample=44100 -ao pcm,pcm:waveheader "test.wma"

In both cases the error is the same:
mplayer: libmpdemux/demux_asf.c:519: demux_asf_fill_buffer: Assertion 
`len > 0 && len <= asf->packetsize' failed.
===============================================================================

Carrying  further and using:
===============================================================================
# mplayer  -vo null -vc dummy -af resample=44100 -ao pcm,pcm:waveheader 
"11 test.wma"
MPlayer dev-SVN-r26936-4.1.2 (C) 2000-2008 MPlayer Team
CPU: Intel(R) Core(TM)2 Duo CPU     E6550  @ 2.33GHz (Family: 6, Model: 
15, Stepping: 11)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
115 audio & 237 video codecs
Can't open joystick device /dev/input/js0: No such file or directory
Can't init input joystick
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 11 test.wma.
ASF file format detected.
[asfheader] Audio stream found, -aid 1
Clip info:
 name: test
 author: test author
 copyright:
 comments:
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio: 16002->176400)
Selected audio codec: [ffwmav2] afm: ffmpeg (DivX audio v2 (FFmpeg))
==========================================================================
[AO PCM] File: audiodump.wav (WAVE)
PCM: Samplerate: 44100Hz Channels: Stereo Format s16le
[AO PCM] Info: Faster dumping is achieved with -vc null -vo null -ao 
pcm:fast
[AO PCM] Info: To write WAVE files use -ao pcm:waveheader (default).
AO: [pcm] 44100Hz 2ch s16le (2 bytes per sample)
Video: no video
Starting playback...
mplayer: libmpdemux/demux_asf.c:519: demux_asf_fill_buffer: Assertion 
`len > 0 && len <= asf->packetsize' failed.


MPlayer interrupted by signal 6 in module: decode_audio
- MPlayer crashed. This shouldn't happen.
  It can be a bug in the MPlayer code _or_ in your drivers _or_ in your
  gcc version. If you think it's MPlayer's fault, please read
  DOCS/HTML/en/bugreports.html and follow the instructions there. We 
can't and
  won't help unless you provide this information when reporting a 
possible bug.


And further:
===============================================================================
# mencoder "test.wma" -ofps 23.976 -ovc lavc -oac copy -o output.avi 
-noskip -mc 0
MEncoder dev-SVN-r26936-4.1.2 (C) 2000-2008 MPlayer Team
CPU: Intel(R) Core(TM)2 Duo CPU     E6550  @ 2.33GHz (Family: 6, Model: 
15, Stepping: 11)
CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
115 audio & 237 video codecs
success: format: 0  data: 0x0 - 0x38383f
ASF file format detected.
[asfheader] Audio stream found, -aid 1
Video stream is mandatory!

Exiting...
===============================================================================

Since it says "Video streaming", does that mean the Wma file in 
particular has no
context but instead has a built-in URL code to obtain the real data over 
the Internet?
Playing the "bad" files shows no Internet activity, so that cannot be 
it.... I think.

So, what is the problem?

Thanks,
Dan