Multichannel PCM to HT receiver

[benjatelcom]

Can anyone tell me if windows will output multichannel PCM via SPDIF to my HT receiver? I have a realtek ALC888 audio chipset intergrated in my mobo, and am feeding a Onkyo SR605 receiver.

Both devices support this, but I don't know for sure if I am sending multichannel PCM out.

Windows is configured for a 6 channel sound system
MSI's realtek utility is configured for SPDIF out, 48khz.
A DD test on a BD I have indicates DD passthrough works.

I wish I knew for sure that kmixer can and is sending all six channels via PCM during non-passthrough operations (such as a game or video that is generating a multichannel mix, for instance, playing a video with 6ch AAC audio, or WMA9 multichannel music/videos).


Update: Windows appears to downmix the system audio to 2 channel, when I put my receiver in direct mode. Previously it was in a DSP mode that mixes the audio to all six speakers. VLC can play AC3 and DTS music to the 5.1 device, which gets downmixed to two channel for output via PCM... VLC can also go direct SPDIF, and my receiver adjusts to the bitstream accordingly. Even WMP9 can't seem to take a 5.1ch WMA without stereo downmix.

Its either AC3/DTS passthrough, or 2ch PCM? I went through this about four years ago attempting to get multichannel sound from games into HT. I was hoping we had made it out of the dark ages, re-encoding surround mixes to AC3/DTS (bluegears and creative).