Install V4L utility packages
sudo apt-get update sudo apt-get install v4l-utils


List the UVC devices connected to the USB port
v4l2-ctl --list-devices

Some devices will display 2 video nodes as follows:

One of the devices is used for regular YUV/MJPEG compression outputs, and the other is used for H.264 coding output. The users can use different programs to open the two devices at the same time, H.264 for streaming and MJPEG for audio recording or computer vision processing.
List the detailed information of each video node
You can check the features of each video node, like compression format, resolutions and so on.
List video0:
v4l2-ctl --list-formats-ext -d 0

List video1:
v4l2-ctl --list-formats-ext -d 1
