I've been trying to find a way to play 5.1 surround sound through my HTPC for over a year now, and I think maybe its possible now through WMC's Netflix plug-in.
I had been talking to a couple people who told me they were sure that they could hear surround sound from Netflix HD films and shows, but on my setup (Nvidia GTX 460 with HDMI audio/video out to an Onkyo receiver) I wasn't able to get 5.1 at all from the rear speakers nor was my receiver lighting up, all I could ever get was stereo. For awhile I thought maybe they had their systems set up incorrectly... like maybe they were pushing audio fill to all speakers, or maybe they were just hearing things or something. I called Netflix' technical support who were pretty much clueless, but assured me that because of Silverlight the ability to output to surround sound was available (which I sort of already knew). I scoured the internet looking for any clue anywhere about how to get 5.1 on Netflix on my HTPC, and eventually gave up, and got a Roku 2 XS.
Recently another person told me that they were certain they were hearing surround sound from the Netflix plug-in for WMC. After a bit of back and forth and confusion on my part it seems like maybe they're right. I had to do something really weird to get it to work for me though. I had to set my Nvidia play-back device in Windows 7 from 5.1 to Stereo. Then in WMC, I had to go to General, and then to WMC Setup and change my audio there to 5.1. Now on content that I know has 5.1 audio I'm finally hearing surround sound.
Here are my issues. Even though my surround sound speakers are active, my receiver isn't lighting up. By lighting up I mean that usually when I play surround audio I get like the Dolby Digital symbol popping up, or I get TrueHD popping up... that sort of thing. Not getting anything at all isn't too unusual, I have a few mkv files that are in surround sound that don't make my receiver light up, but with the Roku I almost always get some sort of DD symbol or something showing up. When I play stereo programming in Netflix, I only hear stereo from my speakers, so I'm fairly confident that I'm not experiencing any sort of speaker fill or anything, and surround sound only seems to pick up surround sound stuff like music, squealing tires, general sound F/X, that sort of stuff. I guess what I'm wondering is, does this seem normal, and is anyone else experiencing the same?
The other issue is that it really sucks to have to set my Windows system to stereo in order to hear surround sound in WMC. I use my htpc for a number of things including gaming, and having to toggle stereo and 5.1 is a pain in the butt.
So the Too Long, Didn't Read point of this post is that, Netflix in WMC appears to support 5.1, but its seems sort of janky, and I'm looking to share notes with others.