I wander if the vid_de signals (there are 2 of them in Cyclone 10 implementation because the IP outputs 2 pixels at a time.
My question is if the vid_de signals, which are Video Data Enable, behave consistent - always '1' during Active Video time or it may introduce Backpressure by going '0' sometimes?
vid_de is input port to Intel FPGA HDMI IP that indicate active picture region only.
This is input port controlled by user logic design and not output port from HDMI IP.
If HDMI IP see "1" on vid_de then HDMI will process the data as "active video".
Sorry, I am not aware you are referring to HDMI sink.
I am not familiar with pixel valid signal.
If you look at the next page of HDMI user guide doc (page 102)
Are you looking for something like these status signal ?