Mobile Paysite: what video/photo formats, sizes, screen sizes?
 

I tried to search, but didn't find anything on here.

Well, what i'm interested in is to know these things:
1. what screen resolutions should i target to?
2. what video bitrate and width/height to use?
as far as i know the videos should be MP4, but not AVC also known as x.264, but as i understand, mp4 stands for DIVX?
3. what photo width/height to use, and what to do with portrait and landscape pics?
4. videos: is it possible to stream them (flash is not supported by majority of devices?) or just to download them, if they can streamed - how?

Maybe there are other things i should know about but forgot to ask?
Thanks a lot for your advice.