When configuring computer vision pipelines (OpenCV), streaming servers (FFmpeg), or webcams on Linux, verifying the exact supported frame resolutions, pixel formats (YUYV vs MJPEG), and frame rates of /dev/video* devices requires Video4Linux2 (V4L2) utilities.

V4L2 Terminal Commands Reference

v4l2-ctl Commandsbash
# Install v4l-utils on Ubuntu/Debian
sudo apt update
sudo apt install -y v4l-utils
 
# List connected video devices (/dev/video0, /dev/video1)
v4l2-ctl --list-devices
 
# Query supported resolutions, frame rates, and pixel formats for /dev/video0
v4l2-ctl --device=/dev/video0 --list-formats-ext