This is how to encode a video to webm format without sound to create a GIF replacement. The ffmpeg utility allows encoding a video in different formats. This is the perfect command for encoding a good quality webm video.
ffmpeg -i gzdoom_2012_11_04_20_34_10_391.avi -ss 00:01:00.000 -to 00:01:20.000 \ -codec:v libvpx -quality good -cpu-used 0 -b:v 500k -qmin 10 -qmax 42 -maxrate 500k\ -bufsize 1000k -threads 4 -vf scale=-1:480 -an hell.webm
This is how to encode with sound in ogg vorbis format.
ffmpeg -i Unreal-noork.wmv -ss 00:00:20.000 -to 00:00:40.000 \ -codec:v libvpx -quality good -cpu-used 0 -b:v 500k -qmin 10 \ -qmax 42 -maxrate 500k -bufsize 1000k -threads 4 -vf scale=-1:480 \ -codec:a libvorbis -b:a 128k output2.webm
The webm format is used increasingly on such websites as 4chan instead of GIF. This allows HD full-color videos in only a couple of megabytes. And it is supported natively by the Firefox web browser. So why not use it on your website?
Read more about webm support on Youtube here: http://www.webmproject.org/users/. This offers the ability to play videos without the need for the problematic flash plugin. I am trying to watch a video on ABC Iview and it will not work at all with the 11.2 flash plugin. That is a problem when they are not using HTML5 and have a limited budget to implement support for this in the future. But hopefully, webm and HTML5 will be the future.