This device shows as 534d:2109 MacroSilicon USB Video in lsusb.

ffplay

Works perfectly! This is the verified solution to use this card: ffplay -f video4linux2 -framerate 50 -video_size 1920x1080 -input_format mjpeg /dev/video0

OBS studio

Buggy.

If it's not working in OBS studio, try switching Video Format some times, or manually switch its Resolution to 1920x1080.

If it's still not working, refer to this guide. (The bug in this guide was already fixed in latest kernel, but give it a try. )

VLC

It works out-of-box, but with very poor performance. The image is very blur and unusable.