[looun]

Strange, flac bitstream is not oficially supported for HDMI.

Yeah. It is not a defined codec in IEC 61937 standards.

yes , only FLAC -> PCM with himedia music APP.
Old DTS-CD 5.1 ( *.wav ) forrmat passthrough work well, for sample.
DSD SACD : not yet supported.

That is what I expected. Generally speaking, bitstream and passthrough are used synonymously these days on forums. One could say that PCM is also a bitstream.
Simon had posted this on Futeko forum:

Not totally sure what you mean by 'audio streams can be played without any audio equipment'. Audio can be bitstreamed via HDMI. 7.1 DTS-HD MA, TrueHD, ATMOS, DTS:X, 192Khz Flac. Pretty much anything.

This can cause some confusion.

so it's right write?
- HDMI passthrough( RAW ) 7.1: DTS-HD MA, TrueHD, ATMOS, DTS:X.
- HDMI bitstream( PCM ): 192Khz Flac.

PS: DSD is support by USB dac but it's other story.