Using FPGA for video conversion

Hi all,

I am trying to show a composite video signal on my DK2 with a latency as low as possible, since I want to control my remote controlled quadrocopter with this setup. In a first step I don't need sensor feedback from the Rift, so the task is boiled down to

• capture the analog video signal,


• resample the color space to RGB,


• deinterlace,


• apply distortion and


• generate the HDMI or DVI output.

For this purpose I am tinkering with a Cyclone V FPGA. The first three steps are working already and I can show the video on a normal monitor with a resolution of 1920x1080p@60Hz. Now, I am trying to show the same on the DK2, which uses a resolution of 1080x1920p@75Hz. From my calculations, this leads to a pixel frequency of 200 MHz (including blanking, vertical and horizontal sync). Unfortunately this is out of the specification of the HDMI transmitter (ADV7513) on my demo board. I have experimented with several frequencies and sync timings with the following result:
Using a refresh rate below 60Hz leads to a color smearing on the rift close to the end of each line (which are defined from top to bottom). My explanation for this smearing is a desynchronisation of the input signal to the rift and the internal pixel refresh rate. If I use my maximum possible pixel frequency of 165 MHz, which leads to a refresh rate of 62 Hz, the picture in the rift is clear and correct again.

Now my question:
Do I risk to damage my DK2 by driving it at 62 Hz and maybe not exact horizontal and vertical sync timings? I mean as long as the electrical parameters are within the HDMI specification, a wrong timing should not damage the electronics or the screen (as long as it is no old CRT display), right?

Cheers,
Stefan