I first asked "How do I convert a video to all formats neccesary for Video For Everybody" on Super User. The answer involved compiling the latest ffmpeg.
Later, I asked "How do I strip the metadata from a quicktime file" here on Ask Ubuntu. The answer to that doesn't work for me, because now I've got the latest ffmpeg compiled in my Ubuntu.
So how do I convert to all the formats necessary using Ubuntu's old ffmpeg (or mencoder or some other CLI answer)?
See my answer to the metadata question; to remove metadata with an up-to-date ffmpeg, you can simply:
As for your actual question: the avconv in the Ubuntu repositories can output H.264, AAC (albeit it doesn't have libfdk_aac, so you'll have to rely on the lacklustre internal ffmpeg AAC encoder), theora video and vorbis audio. I don't know if it supports VP8 video, but if it does then the commands listed in that SU question should work perfectly well.