[mythtv-users] how do you replace your recorded files with smaller, compressed files?

[Evuraan]

I am nearing my disk capacity, and tried to reduce %usage by replacing
 my older recordings with their smaller avis :

mencoder input.mpg -ovc lavc -vf scale=720:480 -oac mp3lame -o output.avi

I then changed the filesize and basename (to output.avi) of the
programid using mysql updates, and deleted  input.mpg

update recorded set filesize = '$SIZE' where programid: = '$GRAMID' ;
update recorded basename = 'output.avi' where programid: = '$GRAMID' ;

But when I tried to play the program from FE, the playback is screwed
up - sometimes too fast, choppy, FF & RW sucks, and F/E even exited a
few times.

Hence this question: How do you guys do it? Am I doing it wrong?
should I be saving those as something other than avi?


$ file output.avi
output.avi: RIFF (little-endian) data, AVI, 720 x 480, ~30 fps, video:
FFMpeg MPEG-4, audio: MPEG-1 Layer 3 (stereo, 48000 Hz)


Many thanks in advance.!