Is DIGITAL 5.1 audio from games possible?

Alright I guess I have a gap somewhere in my knowledge base that is causing me an issue, an now I could use the advice of an expert.

What I have:
Onboard Realtek ALC1200 running through TOSLINK
Sony HT-SS360 5.1 system that handles LPCM and DD/DTS

I know that through TOSLINK, I am limited to 2-channel LPCM if I am not running "native" DD or DTS audio. I also know that an .mp3 is only going to be 2 channel. So just to clarify upfront, I am not trying to get 2-channel sources into surround sound. I have the opposite problem, my concern is games. I know that almost all games have some form of surround sound, but I can't seem to get to it.

For example, when I play Crysis, all I get is 2-channel LPCM audio. I did some research, and I understand that the only way I can get 5.1 through TOSLINK is if Crysis was putting out a DD audiostream, which it obviously does not. So first question is, what type if audio then does Crysis (and nearly every other game) use? I am of the belief that it is lossless "analog" that is being mixed via DirectX (DirectSound). Am I correct?

So this leads me to my next problem. Say for instance I change video cards to a Radeon 5770, that has the same audio chipset that I currently use, but instead outputs over HDMI instead of SPDIF (Toslink). HDMI is capable of 8-channel LPCM. I know this, BUT, will this actually give me true multichannel sound from Crysis and other games? Will the Realtek take the audio streams, which I previously stated that I assume are lossless analog, and convert those to multi-channel LPCM via HDMI?

That brings me to my last question, is digital multichannel audio possible in games on Windows 7 without Dolby or DTS?

The million dollar extra-super-bonus question: If I want digital, multichannel surround sound for GAMES, should I go with say, a Radeon 5770 with a HD soundchip and an HDMI port, or should I get a Asus Xonar HDAV that does lossy Dolby Digital Live encoding in real-time? I would prefer 8 channel LPCM (ATI) over an audio stream that is going through an extra lossy compression (Asus) if possible.

Whew, thanks and lots of love to everyone who actually reads all this!
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  1. Hi,

    If I understand correctly I think you need to encode your game's surround information with Dolby Digital Live or DTS Connect. Some motherboards have the capability and since it will stay in the digital domain all onboard or dedicated sound cards will sound the same. Just look for a sound card that has Dolby Digital Live or DTS Connect ability. I think many Creative sound cards will do what you want with the Creative Dolby Digital Live and DTS Connect Pack for $5 but most of them only have the digital output via 1/8" jack or rca connector, not optical. DD and DTS are compressed and lossy by design by the way.

    I don't know if the 5770 will pass your video game audio. I've been with Nvidia for a long time so I haven't been following ATI. I didn't see any mention of DD encoding on the ATI website. I know you can redirect and passthrough with the Xonar HDAV. The second best choice to uncompressed TrueHD or DTS Master is a quality analog card with 6 analog outputs to your receiver. I initially had my HDAV Deluxe connected that way. The HDAV sounded better with HD movies but with games I think it was the same. I may be that I was concentrating on the screen and sound cues to not get killed versus listening for sound quality. ;) I went back to desktop gaming cause I wanted three monitors for racing sims and am pretty satisfied with Dolby Headphone for sound. :)
  2. Encoding is what sort of troubles me a bit. My understanding of it is, DDL or DTSC is taking analog channels and just compressing them into a stream small enough to fit through a SPDIF. So there is an analog-digital conversion there. And with what I have now, I have 2 analog channels getting converted to digital PCM. So I am hoping, but am not sure, if the ALC1200 chipset which is found on the 5770, will take multiple analog channels and covert them to multi-channel digital PCM through HDMI.

    Uuuuuugh. I really don't want to go with real-time encoding unless I absolutely must. Then again, if there is no way to get multichannel LPCM via HDMI via some automagical analog-digital conversion, then I guess TOSLINK would be as good as it gets? That just makes no sense >,..,<
  3. Ok, I read more on what Dolby Digital Live does. It encodes to a 5.1 bitstream via Wikipedia. "...An important benefit of this technology is that it enables the use of digital multichannel sound with consumer sound cards, which are otherwise limited to PCM stereo or multichannel analog..."

    When you say you have "2 analog channels getting converted to digital PCM." Why are you limited to two channels? DDL will work with 5.1 channels from your game and create a DD 5.1 bitstream. Unfortunately I don't think there is an "automagical" ;) way to do this. There wouldn't be an analog to digital conversion because your game creates the sounds digitally and DDL uses this digital signal.

    So basically you are trying to get 5.1 sound from your computer to a 5.1 surround receiver. Looking at the rear panel of the HT-SS360 you have 2 toslink, 1 digital coax, and 3 hdmi inputs. So 6 analog in is out of the question. You could get a Xonar HDAV1.3 Slim with DDL and combine the audio and video into hdmi. It even has toslink and TotalMedia Theatre. Or maybe you could go dvi to hdmi to your hdmi "sat in" and toslink to "SAT opt in" and hopefully it will combine them. Either way the audio will be compressed.... unless the HDAV doesn't use the DDL and somehow automagically gives you pure unadulterated sound from your game's sound engine. It's possible.
  4. I am limited to two channels because of the bandwidth restriction of the TOSLINK. It only supports 2 channel LPCM or Dolby Digital. The question now I guess is if with HDMI audio I will have more than 2-channel LPCM.
  5. Sovtek, you just described exactly the problem I'm facing right now with my new system. I already tried the Xonar's cards but didn't like the way dd live work in terms of sound quality. I was wondering if you have found a solution that you are happy with. Did you try connection over hdmi port?

  6. I made it easy on myself, and just use the multi analog out. Many receivers have the capability, I know one cable is easier (HDMI or toslink) but I can play in surround sound on every game with no hassle.
  7. Thanks Fester. I was hoping to make the set up a little cleaner with less cables but it looks like it's going to be analog out for games and optical for everything else music etc.
    I've found this utility that automatically switches between analog and digital output devices but didn't have time to test it yet.
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