Welcome to TVPaint Community forums !

So far, the standard for eBooks is Epup3, which is HTML 5 -based = > video and audio files can be embedded.
In general for video the format is mp4 - which is not a compression but a container ( the right video codec is H264).

For the iOS- devices it is also the m4v-container. Embedded videos are well supported on the iOS-devices, even the Kindle Reader App from amazon is supporting video on apple's iPad, iPhone, iPod.

On Kindle-devices the epub3-format has to be converted to amazon's own one, KF8. Most Kindle devices won't play video, only Kindle Fire and Kindle Fire HD does. Streaming video is not supported by amazon, the files doesn't have to be larger than 50 MB ( the customer has to pay the MBs with downloading the ebook ).

Here is list of readers and supported file types ( end of 2012 ). Transl.: ja=yes, nein=no, Geräte=devices

yes, I have both the first kindle, which is only B&W and kindle fire. I've downloaded my 720p WIP which I first converted to mp4 using the H264 codec in Vegas, wherea I further reduced the 2 hour file to only 720x480 to keep the weight down.. and it looks great; the colors are spot on, perfectly matching our original 1080p originals in TVP and the picture on the kindle is as sharp as daylight. After what you have described here I have no concerns anymore of having to replace all my 720p Vegas AVI files back to their original 1080p size before going to e-book. I have already decided to release our film through Amazon's services and it is very helpful to read your affirmation here. Thank you so much.