Some tools like mjpeg_tools or jpegtran can validate JPEG headers per frame.
Use ffprobe (from FFmpeg):
Because there is no "group of pictures" (GOP) to buffer, the delay between a camera capturing an event and your screen showing it is nearly zero. Hardware is Limited: mjpeg video sample verified
Network engineers simulating video traffic over constrained links need verified samples to measure packet loss effects. An unverified sample might already be corrupt, skewing results. Some tools like mjpeg_tools or jpegtran can validate