Still stuck with this.
When I look in Control Panel -> Sound -> Playback I see a number of options. There's a few that relate to my Juli@ card, others that relate to RealTek and then HSRS which is Intel Display Audio. For each, when you double-click on them you can see the "Jack Information". Only HSRS has a jack related to the HDMI port "HDMI Digital Jack". The RealTek ones are linked to ATAPI Internal Jack, Front Panel 3.5mm Jack, Rear Panel Optical Jack. The problem with HSR5 is that while it supports a lot of bit depths, sample rates and formats, it is limited to 2 channels and the encoded formats it supports are all related to DTS and Dolby Digital. When I play a stereo track via WASAPI to HSRS, JRiver will play the tracks.
When I look at the specs of my mobo, I see "10-channel (7.1+ 2 independent multi-streaming) audio subsystem using the Realtek ALC892* audio codec". What I don't understand is why I can't get a Realtek option that uses the HDMI port.
Anyone have any ideas?
UPDATE: I even have problems with stereo tracks with HSR5. Playback was working and then sound cut out (the track was still playing in JRiver). I could not get sound to restart despite JRiver playing the tracks ok.