I'm trying to use some 4.0 Flac files I made. The test file is 4.0 24/96, in each of the cases below I am only changing the WAVEFORMATEXTENSIBLE_CHANNEL_MASK header in the Flac file, Foobar with the WASAPI plugin is the only player I have found so far that seems to support this header properly. Kodi and JRiver seem to have no support at all so kudos for supporting it.
FL+FR+C+LFE - Works properly and detected as 3.1 by receiver
FL+FR+SBL+SBR - Receiver detects 4.0 but only plays stereo; I think this is because the receiver does not support this format
FL+FR+SL+SR - This is output as 5.1 causing silent channels when upmixing. The receiver does support this layout.
I'm confused by the FL+FR+SL+SR result, can anyone confirm if their setup does the same? (Can provide a file sample if you message me)
I'm now getting the same behaviour with the integrated WASAPI support in beta 15. Could it be the Intel HDMI driver does not support FL+FR+SL+SR mapping over WASAPI? Any way I can find out if this is the case?