I have old MooV file for QuickTime player. It consists of one "mdat" atom only. One more interesting thing that the size of this atom is set to zero (first 4 bytes of the file are 0). Mac OS 8 QuickTime is able to play it.
Is it possible to get any information, how this movie is encoded?
It was "Graphics" format. A set of images, like GIF, compressed by "Apple SMC". More details are here : https://wiki.multimedia.cx/index.php?title=Apple_SMC