Supported YouTube file formats

Here's a list of some well-known formats that YouTube supports:

• WebM files - Vp8 video codec and Vorbis Audio codecs
• .MPEG4, 3GPP and MOV files - Typically supporting h264, mpeg4 video codecs, and AAC audio codec
• .AVI - Many cameras output this format - typically the video codec is MJPEG and audio is PCM
• .MPEGPS - Typically supporting MPEG2 video codec and MP2 audio
• .WMV
• .FLV - Adobe-FLV1 video codec, MP3 audio

http://www.google.com/support/youtube/bin/answer.py?hl=en&answer=55744