avi to mjpeg conversion is used by users that want to turn ordinary AVI video file into motion JPEG file, essentially a animated picture. Many mutlimedia converters actually do support MJPEG format, so it shouldn't be hard to find one that can do this for you. Just keep in mind that the resulting file will be much bigger, unless you toss away some frames (typically predefined ratio). You can find websites that offer online converters for this task as well.
Updated: August 31, 2023