Why do I get a Critical Warning when connecting a YUV 4:2:2 AXI4-Stream input to the HDMI RX or TX Subsystems?
The problem occurs because the HDMI RX/TX Subsystem v1.0 always assumes that the input is 3 components 4:4:4 and expects the user to pad the unused bits with zeros.
For example, if you select a YUV 4:2:2 AXI4-Stream as the output of the Video In to AXI4-Stream block, this sets the output to be (12 bits * 2 Components * 2 Pixels Per Clock) which turns out to be 48 bits.
The 48-bit output is cascaded to the HDMI TX subsystem, which is why the GUI shows 48 bits on the input.
The HDMI TX Subsystem v1.0 always assumes 3 components (12 bits * 3 Components * 2 Pixels Per Clock) which is 72 bits. The tools then issues the above error due to the mismatch in the data widths.