This file shows a bug with wmv3 video embedded in quicktime containers. If you run

    ffmpeg -i wmv3_in_quicktime.mov foo.mp4

you will get the following spew:

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'cmarrin_sample.mov':
  Duration: 00:00:03.66, start: 0.000000, bitrate: 15248 kb/s
    Stream #0.0(eng): Audio: wmav2, 48000 Hz, stereo, s16
    Stream #0.1(eng): Video: wmv3, 1440x1080, 25.00 tb(r)
FFmpeg version SVN-r15883, Copyright (c) 2000-2008 Fabrice Bellard, et al.
  configuration: --disable-ffplay --disable-ffserver --enable-gpl --enable-postproc --enable-swscale --enable-avfilter --enable-avfilter-lavf --disable-vhook --enable-libfaac --enable-libfaad --enable-libmp3lame --enable-libvorbis --enable-libtheora --enable-libx264 --enable-libxvid
  libavutil     49.12. 0 / 49.12. 0
  libavcodec    52. 3. 0 / 52. 3. 0
  libavformat   52.23. 1 / 52.23. 1
  libavdevice   52. 1. 0 / 52. 1. 0
  libavfilter    0. 1. 0 /  0. 1. 0
  libswscale     0. 6. 1 /  0. 6. 1
  libpostproc   51. 2. 0 / 51. 2. 0
  built on Dec 16 2008 15:13:59, gcc: 4.0.1 (Apple Inc. build 5490)
swScaler: Unknown format is not supported as input pixel format
Cannot get resampling context
ext

For a more complete description, please see:

    http://lists.mplayerhq.hu/pipermail/ffmpeg-user/2008-December/018306.html

and

    http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-December/057984.html