ffmpeg

rory@ZUBUNTU:/media_library/MythTV/mythExport$ ffmpeg -i BBC-2-England-Never_Mind_the_Buzzcocks--20111212220000.m4v
ffmpeg version 0.8.1-4:0.8.1-0ubuntu1, Copyright (c) 2000-2011 the Libav developers
  built on Mar 22 2012 05:09:06 with gcc 4.6.3
This program is not developed anymore and is only provided for compatibility. Use avconv instead (see Changelog for the list of incompatible changes).
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'BBC-2-England-Never_Mind_the_Buzzcocks--20111212220000.m4v':
  Metadata:
    major_brand     : M4V
    minor_version   : 512
    compatible_brands: isomiso2avc1
    encoder         : Lavf53.21.0
  Duration: 00:29:56.12, start: 0.000000, bitrate: 1498 kb/s
    Stream #0.0(und): Video: h264 (Constrained Baseline), yuv420p, 480x320 [PAR 32:27 DAR 16:9], 1496 kb/s, 25 fps, 25 tbr, 25 tbn, 50 tbc
At least one output file must be specified