how to create video for mpman dvb- 2012

How is it possible to create an video file that could be read from mpman dvb-t 2012 tv decoder? It is an Italian digital tv decoder that plays music, has games but I am unable to find the right way to produce proper film.

Mpman dvb-t 2012 tv decoder read video file frm USB key under the following conditions:

• The USB key must be formatted as FAT32;
• The video file must be avi format using xvid format for the video and mp3 for the audio with a screen size lower than 800x600;

• I suggest the use of avconv program with the followings instruction

  mkdir t  
  find * -maxdepth 0 -print0 | xargs -0 -l -i avconv -i "{}" -vcodec libxvid -q:v 4 -acodec mp3 -b:a 128k -ar 48k -f avi -s 640x272 -aspect 40:17 "t/{}.avi"