I don't believe it downsamples. What are you playing, how is it connnected, and why do you think that?
Yes — you are right, JimH. Apologies: I’m not experiencing any downsampling on the HDMI. Only the down-bitting and down-mixing described above (with input from bob and astromo). I got my “downs” mixed up there! 😊
Sources tried: every sampling rate of PCM (flac, wav, over DLNA, served from a PC running MC, all conversions avoided at every step, see above thread). Devices tried in MC: all. My ANTHEM MRX-1120 AV receiver tells the incoming HDMI channels and sampling rate. The 16 bit truncation is assumed based on the limitations apparent in the device settings in, and reporting by MC on the Id Pi, and referring to bob’s in depth comments re: ALSA limitations above « on: August 06, 2020, 12:25:13 pm ».
So it’s the truncation to 16-bit and the down-mixing to stereo in the ALSA mixer which remains notable. Again, sincere apologies for the false alarm regarding downsampling.
My point, in the bigger picture, is only that the Id Pi would feel more “finished” if a) it had the Hifiberry Digi+ Pro or equivalent as standard, or b) alternatively, if the HDMI limitations were lifted with further development of the Raspberry Pi OS, which of course is beyond JRiver’s control. If I had to pick one, I’d pick b) because right now, as far as I can tell, there is no* DLNA renderer with full 24/192/8ch PCM HDMI out there. No Android TV OS based streaming box does it (even Nvidia Shield Pro 2019, which I own). Apple TV doesn’t. Roku doesn’t. This was actually my main aspiration getting the Id Pi: full HDMI spec covered in a small silent DLNA renderer.
*-Putting aside that there’s some handcrafted ultra-high-end box for $10K somewhere outta Italy or Switzerland or something. I mean: remotely affordable.