Extracts MP4 files from MP.jpg files.

Some phones record motion photos as MP.jpg files. These can be viewed by standard JPG viewers, but in order to get to the motion video that's embedded, we need some way to extract that MP4 video from the MP.jpg file. This extension uses a fairly simple Bash based set of commands to find the MP4 headers and extract that portion of the file to an MP4 video file.

This may not work on all version of MP.jpg which seems to be a proprietary format.