I have just downloaded a film (rental) on Google Play. The playback is faulty. Instead of full screen playback I have only one small section of the screen playing the film. The rest of the tablet screen is either black, of given to displaying a section of film stills. The screen has a mosaic appearance with only one of the collaged square/rectangle shapes actually showing (partial) film playback. I have the latest firmware update. I would appreciate help with this, thank you.
Are you trying to play a rented movie with the Google Movie & TV app? Or, did you somehow download it to your computer and then copy it to the tablet?
Either way, it don't much matter and I highly doubt the suggestion above to use a different video player app will do any good either. As near as I can tell, rented Google movies (or TV shows) are in .wvm (Windows Video Media) format with DRM protection.
The Google Movies & TV aps is totally useless on the 70b. All videos (rented or purchase) from Google will do EXACTLY what you mentioned (that is, only the upper left portion will display). I reported this to Google almost 2 months ago. After several back and forth e-mails the guy said he would forward my info on to the development team. Hopefully they will someday put out and update to fix this for our devices, but have my doubts about that ever happening because these things are really just about totally obsolete now compared to newer devices, like Googles own Nexus 7.
As a side note, you can see EXACTLY the same problem if you use the YouTube app and do a search for the talking cat videos "Oh Long Johnson". Select the one that is 6 years old and it will do EXACTLY the same thing. Try some of the other ones and you will find that some play and others do weird things.
What it boils down to is that the Archos 70b is just really nit picky about videos. They MUST be 720p or lower, and the width/height MUST be a multiple of 16 bits. And, even then, there are other video characteristics it does not seem to like to work with.
In short, you simply can NOT play any Google rented (or purchased) videos on this device. You'll just have to use some other device, or a computer to do that. I know that sucks, but the 70b is a really, really low end tablet. It's a nice tablet in some ways, but also very limited in others.