Script for measuring latency of USB webcams
This is a short python script that can be used to measure the latency and frame rate for a USB camera. It works by displaying a time on the screen, and then displaying the image from a USB camera that is pointed at the screen. The difference between the time shown on the screen and from the image in the USB camera is the latency. The FPS (frames per second) is printed in the console.
In this case the latency is 102.567s - 102.459s = 0.108s
To take a snapshot of the image and save it as a .jpg, press the spacebar. ESC exits and quits program. You'll want to take a few snapshots to get an averaged value. The latency can jump around quite a bit.
You may need to edit the number for the videocam to get the right one on your system.
It requires the OpenCV2 package.