for longer time I'm playing with broken HDMI inputs in my friend's TV, I found that there is TDA19997HL/C1 chip which plays as mux 1:4 for HDMI input signals. For education purpose I've checked datasheet to find information for example how certain input is selected via I2C (control, not DDC) bus. In datasheet there is only information about some "page management", but nothing about any bit in any register!
Of course I could record with logic analyzer / oscilloscope some I2C communication between CPU and chip, then change HDMI input and look how payload is changed in packets...but I don't think it's the correct way to learn anything about that chip...
For any information I would be appreciated!