This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DM648 video port capture

Hi, I use video port0 to capture the yuv data from FPGA,  the rate of frame is 40frames/second. And the codes below:

if(signal)//signal is active indecate that the new frame begins, it's sent by the FPGA.

{

//t1 and t2 are measured by an oscilloscope

    gpio_out(1,11);//set the gpio11 to be high, it's time t1

    FVID_exchange();//call the FVID_exchange()

   gpio_out(0,11); //set the gpio11 to be low;it's time t2

}

and t=t2-t1, sometimes t=~40ms, sometimes t=~80ms

what causes the t to be not same?

Besides, we use pspdriver_1_10_00_09 and bios 5.31.02, and the video driver mode is Legacy mode.