Frame rate of GMSL cameras is very low

[owenbrooks]

The Twizy we use has 8 cameras on it. They use a cable and communication protocol called GMSL to transfer data to a computer. GMSL is specifically supported by NVIDIA, who made a library to read the data from an NVIDIA Drive PX2 computer like we have onboard the car.

They also made a ROS package that we can launch to get the camera images published to ROS topics: https://github.com/BeckerFelix/ros_gmsl_driver

This driver works, but running it as provided, the camera images are updated very slowly, only a few times per second. It would be ideal to achieve 30 frames per second coming in from all 8 cameras at once. We tried running only a single camera, and the frames still came in slowly.

You'll want to start by:

• running the ROS node for the cameras
• running only a single camera
• measuring the frame rate of camera images being published (can try using the ros2 topic hz command)
• measuring the computer's CPU usage with htop to see if processing speed is what is slowing things down
• trying to lower the resolution to see if this speeds it up