[kimburgess]

That's only the case in the (relatively) shiny new 2.1 spec with FRL. Prior versions are TMDS with 3 channels for red, green, blue, along with a clock. The audio and InfraFrames slot into the data islands in blanking periods on those signals.

[phh]

Thanks for the complementary infos. YCbCr420 (which you can't just mux on the channels directly?) dates back to HDMI 1.4 though

[monocasa]

As the source device, you can simply choose not to send YCbCr420.

[kimburgess]

Absolutely - YCbCr 4:2:2 and 4:2:0 use different encodings across the lines to balance bandwidth. Complexity then continues to stack with deep colour pixel packing. There's a beautiful pocket of simplicity for RGB 4:4:4 8bpc which is essentially a direct digital encoding of ye oldy RGBHV signals. More than OK for any retro-comp needs, and a fun starting point for general hacking.