Thus, the genesis of the Atari Beaglebone Expansion or ABX. Integrating the Atari with a Beaglebone as a PBI device, I was able to effectively expand available memory to 140MB on a stock Atari 600XL. This is enough to play around 3.5 minutes of video at 30 FPS.
But, what's a movie without sound? So, I modified RastaConverter to reserve room on each scan line of the raster program to write a digital sample to POKEY and then to restore the register that had to be modified in order to do that. Then I positioned additional writes to POKEY in the intra-frame kernel so that the audio plays uninterrupted.
You can see the result in this YouTube video:
RastaMovie can also output versions of the movies that can be played on Atari800 and Altirra. It takes advantage of the fact that segment loads are instantaneous to simulate large amounts of RAM. These executables won't work on real hardware however. Check out birds.zip, epic.zip and im.zip in the downloads area of RastaMovie's github home page.