A short explanation of how videos are compressed
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theoretically, no matter how long a video is, if there is no movement and a still frame, that video will have an extremely small size. That is because compression algorithms recognize patterns, and instead of repeating the same pattern over and over, the pattern is saved once and then told to repeat that pattern in various parts of the screen.
A video where the entire screen is in motion will have a very large file size because it can't be compressed much. Likewise, the more colors in the video, the larger the file size will be. A monochrome video will be quite small. So, There is no reason to not use a lot of compression on a video which has a fixed background with only the performers fucking as the motion. the compression techniques only save the CHANGES to the image on the screen.