In Motion JPEG or MJPG full image information is transmitted as a JPG graphic. Unlike H.264 this results in increased data rates for smooth frame rates. Motion JPG streams are rapidly noticed as “bumpy” for the audience. MJPEG is pure 90ies! Wikipedia

Motion JPEG is supported by Restreamer. But the encoding requires processing power. Raspberry Pi is not suitable for this. Restreamer relies on H.264 via RTSP to allow even at low bandwidths liquid streaming.