Bu sekilde bir sey buldum denedim ama beceremedim

#!/bin/bash
#script erzeugen von Testbildern für die Bildanalyse 

find . -iname "*.avi" -type f | while read FILE
 do  
     NEW="${FILE#./}"
     ffmpeg -i "$var" -deinterlace -r 0.25 "${NEW%.avi}%3d.flv" 
 done