HSTX has a built in TMDS encoder, and as far as I can tell, it has all the functionality of the SIO TMDS encoder.
You can configure it to directly consume any line buffer with any pixel format, from 1 to 8 bits per color channel. It even supports formats with different numbers of bits per channel like 8-bit RGB322 and 16-bit RGB565.
what's the fun in that though?
i have the impression, that the main motivation for this project was learning the intricacies of TMDS encoding and providing an open implementation as reference for other ppl, who want to learn too.
there are too many black box electronics these days, so it's very much welcome to virtually open them up, by providing software equivalents of their operation.
The nice part about using SIO seems to be that you can do the tdms encoding there. With hstx you need the output bitstream in the right format already which seems like you might be back to needing the CPU to do the encoding.