Hi Manichean. checkout the following
Thought I would let you know that epub with video works. Hard13 never followed up the post but I will let you know what I did to get it working, so here goes......
I just made a simple webpage, ran this through IE and FIREFOX to see if the video would show. Neither showed the video (well on my system anyways). Ran it through SAFARI and the video played. So I knew I had got the code right. I recommend using SAFARI for testing the code.
Then used CALIBRE to condense to an EPUB (produced and OCF) I uploaded the single OCF to my ipod touch and it worked fine (for some reason it would not play OGG file formats, guess it likes MP4 etc instead.
The following was my html file.
<video src="aa.m4v" NOTE will try MP4 next and post result
You can then jazz this up however you like. I hope this helps you and anyone else looking for video in epub.
Best wishes Jason