This may help:
Transcoding is made easy by using several GUI's or command line tools. Of which I previously posted this answers, I hope this help you.
What is the best tool for converting and reading video to be played on DVD players?
How can I maximum compress video files?
Additionally, there are a few other answers in this forum under the "video" tag which may be useful for you.
P.S. If you are using a 64 bit system you may be interested in this: How to install 32 bit software in 64 bit system from within the Israel Linux Remix Team, posted by me in the past. Certain software may misbehave when using this procedure but it is yet good for transcoding or downloading from youtube the appropiate video file (.flv).
BTW: You can upload almost any video file with almost any codec which Youtube will transcode, suggested by Youtube:
YouTube can accept almost any video
format for upload, but for most users
we have found the following settings
give the best results.
Video Format: H.264, MPEG-2 or MPEG-4
preferred Aspect Ratio: Native aspect
ratio without letterboxing (examples:
4:3, 16:9) Resolution: 640x360 (16:9)
or 480x360 (4:3) recommended Audio
Format: MP3 or AAC preferred Frames
per second: 30 Maximum length: 10
minutes (we recommend 2-3 minutes)
Maximum file size: 1 GB