Convert H264 to MJPG

Converting H.264 Encoded Video Files directly to Motion JPEG Videos (.h264 to .mjpg conversion) should be possible and quite straightforward, even though your options might be limited.

Use one of several video editing programs or (online) conversion tools, such as the Freemake Video Converter or MediaCoder, which allow users to import H264 videos and re-save them in MJPG format.