We have been using FFmpeg quite a bit lately for a number of projects. One such project has us encoding uploaded videos into a variety of formats including mpeg4 for iOS devices. So we fired up FFmpeg, to run a test transcoding with the following command:
ffmpeg -i test.mp4 -acodec libfaac -ab 128kb -vcodec mpeg4 -b 1200kb -mbd 2 -flags +4mv+trell -aic 2 -cmp 2 -subcmp 2 -s 320x180 -title X final_video.mp4
We were immediately greeted by an Unknown encoder ‘mpeg4′ error. There are apparently some licensing issues between ftp-masters and FFmpeg. Not being a lawyer, I cannot advise on the legality of the following workaround, so this is for informational purposes only.
Turns out we can get ‘full’ installs of FFmpeg from the debian-multimedia repo. This was as simple as first opening our sources list:
$ nano /etc/apt/sources.list
http://www.debian-multimedia.org lenny main, installing the debian multimedia keyring:
$ aptitude install debian-multimedia-keyring
Run an upgrade
$ aptitude upgrade, and you should be set. Running that same FFmpeg command output our video.