Here’s how to convert and HDTV/Hi-Res video into one that can be easily viewed onto a limited resources hardware like a mobile.
It uses ffmpeg. To install it on debian-like
$sudo aptitude install -P ffmpeg
while to convert the video
ffmpeg -i holiday.avi -sameq -s wvga -ac 2 -ab 192K holidays-low.avi
it works as well with mkv files.
if you get the message like
[mpeg4 @ 0x99e1e80]timebase not supported by mpeg 4 standard
try adding the following flag before the output file