A hands on look at command line encoding. Robert has been writing some help on this. I think he'll update this soon.

WebM

An overview of usefull ffmpeg/avconv options related to encoding WebM files.
 http://wiki.webmproject.org/ffmpeg and http://ffmpeg.org/ffmpeg.html#libvpx

http://rodrigopolo.com/ffmpeg/cheats.html

Creating h264 files that work on many mobile devices

http://h264.code-shop.com/trac/wiki/Encoding

General x264 encoding guide

http://ffmpeg.org/trac/ffmpeg/wiki/x264EncodingGuide

Assessment Task

Create a video file with ffmpeg or aviconv