@balbes150 —> BINGO!!!
It works, but I had terrible crackles at first.
A reboot solved it, not sure where this came from.
Webradio was tested with an Odroid Hifi Shield +, so basic I2S is OK.
I need to do further testing with different formats and sampling rates, but need to build my library on VIM for that first.
After that I will try a pcm512x based DAC.
Edit Playing upto 352.8Khz/24bit, currently I do not have anything higher than that, but this means it works just as well as on an Odroid, using the same material.