What are the MP4 specs

The movies are encoded in H.264. For movie size if you have a 16:9 aspect ratio you should get 1280x720 for high quality and for good quality half the size, 640x360. For other aspect ratios you get the same approximate number of pixels, so at 2.35:1 you’ll get whatever pixels width and height wise to get you 1280 x 720 = 921600 ish pixels, but with the width also rounded to the nearest 32 pixels.