I have place mp4 files from "Place from URL" option in the document and its place nicely when I have prepared epub and publish online then doc display empty page after discussion with adobe they told me that mp4 not compatible, so i have to convert video in FLV extension then it will work, which is impossible for me. MP4 is most useful extension and Adobe need to solve this and make mp4 compatible for it.

Keep in Mind when we place from "Place from URL" Not direct placing of MP4 file, "Place form URL" Option.

Thanks!