I am using an ADV7619 to receive 4k HDMI signal. It's pixel bus is configured in 2x24-bit 4:4:4 SDR interleaved mode. The pixel bus is connected to an FPGA.
I have an issue, that sometimes, when I switch video on the input, the ADV7619 is not able to produce correct VSYNC signal. At vs_bad1.png, the signal changes it's value 4 times within a single frame.
However, sometimes it works perfectly fine. The correct VSYNC should look like the one on vs_good.png.
By switching the input HDMI on and off, i was able to produce the two images with the same configuration.
Sometimes, I've experienced small glitches in the signal too (see vs_bad2.png).
Can you give me some advice please? I think the problem may be at the HDMI input side, but I'm not sure. In both cases, I was able to read out correct frame measurements from the ADV7619.