How to convert mpeg to YouTube video: You have mpeg file but you would like to convert it to Adobe Flash video format. To do that, check it out here how you can do that.
How to convert file WMA to MP3 in Ubuntu 11.04: You have mp3 player and a lot of musics in WMA format. Access this post to see how you can convert them to mp3 format.
How to convert YouTube video to mpeg: A great advantage to do that is regarding the compaction. You can decrease the size of the file. Check it out here.
How to compile and install ffmpeg in Ubuntu 11.04: FFmpeg permit us to manipulate audios and videos files. It has support for most existing file formats. However, you need to enable some encodings. See here, how you can do that.