Hi, we have a collection of old home videos that were saved in AVI format a long time ago. I want to convert these files to a more modern format because the Totem Movie Player that comes with Ubuntu 10.4 seems to be the only program capable of playing them.

The files seem to be encoded with a MJPEG codec, and playing them in VLC or Windows Media Player plays only the sound but there is no video.

Avidemux was able to open the files, but the quality of the video is severely degraded: The video skips frames and is interlaced (it's not interlaced when playing it in Totem).

Neither ffmpeg nor mencoder seems to be able to read the video stream. mencoder reports that it is using ffmpeg's codec. Here's a section from its output:

==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
[mjpeg @ 0x92a7260]mjpeg: using external huffman table
[mjpeg @ 0x92a7260]mjpeg: error using external huffman table, switching back to internal
Unsupported PixelFormat -1
Selected video codec: [ffmjpeg] vfm: ffmpeg (FFmpeg MJPEG)

while running ffmpeg produces the following:

$ ffmpeg -i input.avi output.avi
FFmpeg version SVN-r0.5.1-4:0.5.1-1ubuntu1, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --extra-version=4:0.5.1-1ubuntu1 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-vdpau --enable-bzlib --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --enable-zlib --disable-stripping --disable-vhook --enable-runtime-cpudetect --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --enable-libdc1394 --enable-shared --disable-static
  libavutil     49.15. 0 / 49.15. 0
  libavcodec    52.20. 1 / 52.20. 1
  libavformat   52.31. 0 / 52.31. 0
  libavdevice   52. 1. 0 / 52. 1. 0
  libavfilter    0. 4. 0 /  0. 4. 0
  libswscale     0. 7. 1 /  0. 7. 1
  libpostproc   51. 2. 0 / 51. 2. 0
  built on Mar  4 2010 12:35:30, gcc: 4.4.3
[avi @ 0x87952c0]non-interleaved AVI
Input #0, avi, from 'input.avi':
  Duration: 00:00:15.24, start: 0.000000, bitrate: 22447 kb/s
    Stream #0.0: Video: mjpeg, yuvj422p, 720x544, 25 tbr, 25 tbn, 25 tbc
    Stream #0.1: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
Output #0, avi, to 'output.avi':
    Stream #0.0: Video: mpeg4, yuv420p, 720x544, q=2-31, 200 kb/s, 90k tbn, 25 tbc
    Stream #0.1: Audio: mp2, 44100 Hz, stereo, s16, 64 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Press [q] to stop encoding
frame=    0 fps=  0 q=0.0 Lsize=     143kB time=15.23 bitrate=  76.9kbits/s    
video:0kB audio:119kB global headers:0kB muxing overhead 20.101777%

So the problem is that output does not contain any video, as evidenced by the video:0kB at the end.

In all of the above cases the audio comes out fine.

So my question is: What can I do to convert these files to a more modern format with more modern codecs?