I am using OpenGL to stream PAL videos from 7 channels, then composing the video onto display. The latency is critical to our project. each time a whole YUV frame is captured, I would convert it into RGB, then send it to the GPU through a PBO buffer. Using gettimeofday, I can see this process takes less than 40 ms. Yet the measured glass-to-glass latency is 180 ms.
So, besides optimizing the frame process time, is there any other settings in the system that I could tune to reduce the display latency?