The source device needs to be able to output PCM, so from what you’ve listed the best you can do is Dolby Digital (the HD621 doesn’t decode anything, so it passes the DD onto the processor). The 861 will report the input that it receives, but should upscale to 96k internally.

What do the speakers report?

Brian

Main: G65, MD600 Sooloos, MC200 Roon Core, MS600, 210, 218, UHD722, DSP5200SE, DSP5200HCSE, M6 & DSW.2
System 2: AC200 MS200, WiiM Pro+, M6.
Other: DSP5000 (96/24v1), DSP3300.