This post describes how to convert multimedia files in Debian. You will find there description of installation process of necessary software (via sources.list file). We will sign added repository. To convert software we will use mencoder, ffmpeg and ffmpeg2theora tools.
To convert *.ogv to *.avi file you can use (ogv2avi):
mencoder -idx input.ogv -ovc lavc -oac mp3lame -o output.avi
Offcourse there must be installed mencoder. To install it:
echo "deb http://debian-multimedia.org/ sid main" >> /etc/apt/sources.list
wget http://www.debian-multimedia.org/pool/main/d/debian-multimedia-keyring/debian-multimedia-keyring_2008.10.16_all.deb
dpkg -i debian-multimedia-keyring_2008.10.16_all.deb
rm debian-multimedia-keyring_2008.10.16_all.deb
aptitude update
aptitude install mencoder w32codecs
wget http://www.debian-multimedia.org/pool/main/d/debian-multimedia-keyring/debian-multimedia-keyring_2008.10.16_all.deb
dpkg -i debian-multimedia-keyring_2008.10.16_all.deb
rm debian-multimedia-keyring_2008.10.16_all.deb
aptitude update
aptitude install mencoder w32codecs
Some other converts (ffmpeg required):
*.flv to *.ogv (flv2ogv):
ffmpeg -i input.flv -acodec vorbis -ac 2 -vcodec libtheora -f ogg output.ogv
*.ogv to *.flv (ogv2flv):
ffmpeg -i in.ogg -b 384000 -s 640x480 -pass 1 -passlogfile log-file out.flv
*.ogv to *.mpg (ogv2mpg):
mencoder -idx input.ogv -ovc lavc -oac lavc -lavcopts vcodec=mpeg2video -of mpeg -o output.mpg
The best tool to convert other video formats to Ogg/Theora is “ffmpeg2theora”.
What you should never do is use the “-acodec vorbis” option of ffmpeg. Instead use “-acodec libvorbis”. This small change is very important. The former uses the the internal FFMPEG encoder, the latter uses the libVorbis library.
The internal ffmpeg vorbis encoder is about the simplest possible encoder that produces working output. It sounds terrible compared to the reference encoder. On a typical musical input the ffmpeg encoder set to 128k produces quality which is obviously worse than libvorbis at 32kbit/sec.