this work for my osx 10.9
give -b a high value to maintain quality
this script cut my 1080p video to half size
[bash]
#
for f in *.MOV; do ffmpeg -i "$f" -vf scale=-1:720 -crf 18 -b 7000k -preset veryslow "${f%.*}.mp4"; done
#
[/bash]
this for old .AVI with motion jpeg
note to define 2 channel audio, and change frame rate to 30
[bash]
#
for f in *.AVI; do ffmpeg -i "$f" -strict experimental -acodec aac -ac 2 -r 30 -crf 18 -b 4000k -preset veryslow "${f%.*}.mp4"; done
#
[/bash]
