I have mjpg-streamer running on an Orange Pi Zero 2 to stream a USB cam. The default 640x480 works. And when I change the resolution to 1280x720 it works. But I'd like a lower 16:9 resolution, and neither 854x480 or 640x360 works. The log file says The specified resolution is unavailable, using: width 640 height 480 instead. Is there a way to figure out what resolutions are supported? And any way I can stream at a low 16:9 resolution?
I'm not sure if this is off-topic because it's an Orange Pi, but the question about mjpg-streamer should apply equally well to a Raspberry Pi.