Converting to WebM, OGG/Theora and MP4.

UPDATE: Now that ffmpeg 0.6 is everywhere, and the preset are good enough, the easiest way to convert a video to WebM is:

$ ffmpeg -i foo.avi foo.webm

Of course, if you want to tweak the transcode options, RTFM ;)
---

If you want to use the <video> tag, you need to encode your video to 3 formats:

• WebM/VP8
• OGG/Theora
• MP4/h264

Building ffmpeg (version >= 0.6)

Create a directory, let's say "myvideos". All the comming commands will make sure that everything stays in this directory. Your system won't be altered.

Downloads:

• ffmpeg source code: here.

dependencies:

• vorbis: here (the version of you distribution should be ok: libvorbis-dev);
• x264: here;
• faac: here;
• theora: here.
• vpx:
  

  git clone git://review.webmproject.org/libvpx.git

Build:

mkdir ~/myvideos/dist

• un-compress;
• go to the source directory;
• ./configure --prefix=~/myvideos/dist && make && make install

Let's build ffmpeg:

$ LDFLAGS=-L$~/myvideos/dist/lib \
CFLAGS=-I~/myvideos/dist/include \
./configure --prefix=~/myvideos/dist --enable-gpl\
--enable-nonfree --enable-libvpx --enable-libvorbis\
--enable-pthreads --enable-libx264 --enable-libfaac\
--enable-libtheora
$ make && make install

Convert

~/myvideos/dist/bin/ffmeg

But first, you need to tell where to find libraries:

export LD_LIBRARY_PATH=~/myvideos/dist/lib/

Here are my 3 command lines to convert to WebM, OGG/Theora and mp4:

• OGG/Theora

  ffmpeg -i input.mov \
    -acodec libvorbis -ac 2 -ab 96k -ar 44100 \
    -b 345k -s 640x360 output.ogv
  

• WebM/vp8

  ffmpeg -i input.mov \
    -acodec libvorbis -ac 2 -ab 96k -ar 44100 \
    -b 345k -s 640x360 output.webm
  

• MP4/h264

  ffmpeg -i input.mov \
    -acodec libfaac -ab 96k \
    -vcodec libx264 -vpre slower -vpre main \
    -level 21 -refs 2 -b 345k -bt 345k \
    -threads 0 -s 640x360 output.mp4
  

Hope it helps.