Problems with the video decoder on the DE2- Board

I think it's better to upload a simpler design, without counting the lines. Now I only count the clock cycles during a single line.

The Datasheet of the Decoder says that there are 1728 clock cycles per line. When I ignore the blinking LEDs my counter puts out 1726. That would be right, because I don't count during the HSYNC interval.

But as I already mentioned all the other LEDs are blinking, which means that there must be some lines with different lengths. And that doesn't make any sense to me.

The ADV7181B Video Decoder runs nearly in default setup.

Can it be the PAL Output of my camera, which lets the decoder do such things? Or have I a mistake in my design.

Thank You