hum. afaik you can only have direct-linking from ochs if you have a prem. acc

you should host your files on some dedicated root or s.th. like this.

flash will only support mp4 and flv.
html5 will only suppoert mp4 and some mobi-format (can't remember which)
Avi files won't work. you have to reencode them.
On reencoding files you'll propably have a small quality-loss. That's s.th. you have to deal with.
but using the right scripts you can reencode this files without much loss.