I currently built an audio streamer with DAC2 HD, and wait for the DSP module and microphone to arrive. This one is dedicated to audio only (Internet Radio, spotify, local hires files). I'm truely amazed at the quality.
I have quickly set up a second streamer, just for video, no audio, no pictures, no games or whatever. This one is based too on a Raspberry Pi4 B. Sadly, OSMC is currently not supporting the new Raspberry Pi 4, but it will surely come. At the moment so, I installed a Libreelec + Kodi 19 but intend to switch to OSMC asap.
My concern here is that my Sony Bravia TV seems to cap the volume very very low (it's plugged with toslink to the amp) and I have to push the amp quite high to achieve the same volume as I have with cd player or audio streamer (classic RCA levels from DAC2 HD, as usual). This seems truely to be the TV toslink output that has somehow a software volume set too low (and yes I tried all the config/system/audio options I could find on the Bravia), as when I plug directly the PS4 toslink to the amp, suddenly it's quite louder, but through TV, it's a pita to hear something unless you triple the volume...
Sooo, after that digression, I'd like to be able to play a movie/serie episode from the streamer (Kodi/OSMC), having the video content sent classicaly through micro-cdmi to TV, but at the same time, have the audio OF THE MOVIE sent through GPIO I2S to a Hibiberry DAC I'd buy for that and use the RCA output as the audio source for the amp.
So I don't intent to listen to the movie sound through TV via toslink to the amp, but rather well to have the movie sound sent to the DAC HAT, to the amp through its RCA.
It's so not a matter of movie to HDMI, with sound, but better audio file replay through DAC, no, it's Movie sound to DAC I'm asking if it is possible :-).
All the best,