Video Corruption or Flicker on Mac OS X - KBA96023

Version: **

 

Question:

When a UVC device is connected to a Mac, the video flickers or glitches when the CPU load is increased. How can one fix this?

 

Answer:

This is a known issue with Mac OS X that has been fixed in OS X Yosemite (10.10). For earlier versions of OS X, the video flickering can be prevented by killing the VDCAssistant process and restarting the video stream. 

To kill the process, use one of the following steps:

  1. Open a Terminal by going to Finder > Applications > Utilities > Terminal. Then type the following command: sudo killall VDCAssistant 
  2. Open Activity by going to Finder > Applications > Utilities > Activity Monitor. Look for the VDCAssistant process and click ‘Quit’ or ‘Force Quit’. Read Apple’s KB article here for more details on quitting a process from Activity Monitor.

Killing the process will terminate any video stream that you have open, so you will need to restart that stream. 

In addition, if you have your own video viewer application, you can add relevant code to kill VDCAssistant before you start the video stream.