Spdif passthrough for games

[alto123]

Hello,
I have a home theater system which I connect from my computer through SPDIF optical cable. I have the following mother board and inbuilt sound card - Gigabyte 880GM - USB3, sound card - Realtek 892ALC which has Dolby Digital Live. I have managed to passthrough audio using AC3 filter when playing through Media player classic every processing is done by the AVR. But I want that from games too, the passthrough is not happening for games, for which I want the sound to be processed by AVR not sound card. Be it 5.1 or 2.1 I want complete passthrough. Is it possible to do?

 

[erly_Cuylers]

which OS do you use? it does not nessessarily have to be pass-through unless you want the raw signal. digital output would still be decoded and converted by your AVR. perhaps you can try the normal digital out rather then SPDIF pass through?

 

[gamerk316]

Welcome to the world of SPDIF; hence why I HATE it with a passion...

The only way a soundcard does nothing is in the case of SPDIF In->SPDIF Out. Every other audio path will at least go through some of the soundcards processing, be it hardware or driver level.

 

[alto123]

which OS do you use? it does not nessessarily have to be pass-through unless you want the raw signal. digital output would still be decoded and converted by your AVR. perhaps you can try the normal digital out rather then SPDIF pass through?

I am using Windows7 64bit home edition.

What is normal digital out?

 

[alto123]

Welcome to the world of SPDIF; hence why I HATE it with a passion...

The only way a soundcard does nothing is in the case of SPDIF In->SPDIF Out. Every other audio path will at least go through some of the soundcards processing, be it hardware or driver level.

Yes there is an option to check SPDIF In->SPDIF Out in realtek audio control panel tab. That is checked too. Still nothing comes. Please help to find a solution.

 

[erly_Cuylers]

digital output is still carried through the SPDIF Toslink. typicly you have to specify you want "pass-through" at the apllication level. I was suggesting you use digital out put without "pass-through. unless I'm mistaken digital output will be decoded and converted by your AVR.

 

[gamerk316]

SPDIF passthrough should ONLY be checked if you want to pass through an input from the SPDIF INPUT port directly to the SPDIF OUTPUT port. Otherwise you'll get a null output...

The only thing you should have to do is enable the SPDIF output as the default output device from the windows control panel. That should at least result in the output to the AVR...

 

[alto123]

I have unchecked SPDIF In->SPDIF Out checkbox. Still no improvement. I can increase or decrease the volume while gaming whereas it is not possible when playing audio through Media player classic, that means processing is done by the AVR, but is it not happening while gaming....

 

[gamerk316]

Depends on how things are set up. Even using SPDIF output, you still go through the soundcards driver layer, and theres nothing you can do about that. I suspect that using AC3 filter for media player is the primary reason why you are getting different behavior between WMP and games.

 

[alto123]

Depends on how things are set up. Even using SPDIF output, you still go through the soundcards driver layer, and theres nothing you can do about that. I suspect that using AC3 filter for media player is the primary reason why you are getting different behavior between WMP and games.

But if I do not use AC3, then music quality is too bad and I can tell that processing is done not only by the AVR but the sound card too. Volume bar also works in windows and applications. To use AVR it is recommended to use AC3 filter and do some modification, if not used sound is pathetic. I think I should not uninstall this. There must be a solution for gaming....

 

[gamerk316]

^^ Nope. AC3 is basically a plugin for music playback software, but theres no way to get it to work for games. Hence, you are getting different behavior between the two.

 

[alto123]

^^ Nope. AC3 is basically a plugin for music playback software, but theres no way to get it to work for games. Hence, you are getting different behavior between the two.

I don't want AC3 to use for games. Just the processing to be done only by the AVR not sound card, and it is not happening. Gaming sound though AVR is way too bad.... no solution getting....

 

[gamerk316]

^^ Thats, again, the downside to using SPDIF: Crappy audio quality.

Can you connect to the AVR via analog? Or connect directly to the soundcard?

 

[alto123]

^^ Thats, again, the downside to using SPDIF: Crappy audio quality.

Can you connect to the AVR via analog? Or connect directly to the soundcard?

I think no, no analog cable is provided too. The speakers has 2 naked wires(red & black) which can be inserted to AVR. But not any thing like 3.5mm jack....

 

[gamerk316]

^^ Well, you could buy a cheap RCA to TRS converter cable, which would allow direct hookup to the soundcard...

What I *think* may be happening, is using AC3 filter may be doing teh opposite of what you think, and making the soundcard do more work cleaning up the signal, resulting in a better sounding audio output. Since AC3 filter can't be used outside media programs, however, audio produced in games is being sent with only minimal enhancement, resulting in lower quality audio.

Connecting to the soundcard via analog would remove the AVR from the equation, allowing us to figure out where exactly the audio quality problem lies.

 

[erly_Cuylers]

it's still my best guess that the basic configuration for alto123's setup is incorrect.

alto123 if you would please look at your

1. HD Audio Manager

2. Windows 7 Sound Settings

and tell us everything you have checked and set including SPDIF settings and output device?

also you may want to check your Games's sound settings set it to digital if possible game's are not my strong suit but it may just not be possible to output any given game through SPDIF. have you tried other games?

cheers, erly

 

[alto123]

Ok, telling about my sound settings -
In HD Realtek audio manager: Digital output(optical) [2nd tab] is made as default through Set Default Device. In default format Doly Digital Live (5.1 surroung) is choosed from dropdown.
In windows sound under playback tab Realtek Digital Output(Optical) is ticked as green. In it properties under Supported formats DTS Audio & Dolby Digital both are checked which is under Encoded Formats. 44.1 KHz, 48.0 KHz, 96.0 KHz checked which are under Sample Rates (192.0khz is not checked as Test sound produced nothing so unchecked it).
That is it. Nothing more has been done.

One thing to note that Black Ops has digital audio option to choose from and it is selected as audio settings. Still......

 

[erly_Cuylers]

Click on Start>Control Panel>Hardware and Sound>Sound.

tell me what each device is listed under the playback tab and which is set as default (with the little green check mark).

erly

 

[gamerk316]

In HD Realtek audio manager: Digital output(optical) [2nd tab] is made as default through Set Default Device. In default format Doly Digital Live (5.1 surroung) is choosed from dropdown.

That should force all 5.1 audio to Dolby standard. But again, thats still being done driver side, so you are still going to go through some soundcard audio processing.

In windows sound under playback tab Realtek Digital Output(Optical) is ticked as green. In it properties under Supported formats DTS Audio & Dolby Digital both are checked which is under Encoded Formats. 44.1 KHz, 48.0 KHz, 96.0 KHz checked which are under Sample Rates (192.0khz is not checked as Test sound produced nothing so unchecked it).
That is it. Nothing more has been done.

This shouldn't matter; playback only informs windows of what can be played back at the other end of the chain, but if DDL is already forced, this shouldn't matter. I would disabled 96KHz though, as Dolby is incapable of encoding to that high a bitrate via DDL.

Only other thing that you should have to do is make sure windows is configured for 5.1 speaker output.

 

[alto123]

Only other thing that you should have to do is make sure windows is configured for 5.1 speaker output.

How to do that please clarify?

 

[gamerk316]

Via Windows Control Panel; make sure the audio output in the sounds section is set to 5.1. Thats the only thing I can think of that could be causing the problem at this point...

 

[palladin9479]

Hello,
I have a home theater system which I connect from my computer through SPDIF optical cable. I have the following mother board and inbuilt sound card - Gigabyte 880GM - USB3, sound card - Realtek 892ALC which has Dolby Digital Live. I have managed to passthrough audio using AC3 filter when playing through Media player classic every processing is done by the AVR. But I want that from games too, the passthrough is not happening for games, for which I want the sound to be processed by AVR not sound card. Be it 5.1 or 2.1 I want complete passthrough. Is it possible to do?

First and foremost, what receiver do you have? That will determine what you can and can not do.

Also AC3 is an audio format, the source audio must support it. For MPC it's a plugin, but for video games the game software must be programed to use it, I doubt you'll find many. In the games themselves you must enable DDL or some form of environmental audio effects, otherwise you'll just get 2 channel PCM coming out. Your sound card also needs to support whatever format the game is wanting to use for 3D positional audio, it's usually EAX these days. If the card does not support EAX or the game's not handing over it's audio data in a 3D compatible format, then you'll just get 2-channel PCM.

This has absolutely nothing to do with digital SPDiff / Coax / HDMI / 6 channel analog connections. Its the audio source not passing 3D environmental data to the sound drivers. If you connect using 5~7 channel RCA wires you will still only get 2-channel audio, your sound drivers will employ software to determine a pseudo-environmental effect. If you employ digital (coax / SPDiff) connections then whatever source audio will be passed to the receiver, then it will use it's hardware to perform the environmental effects. Setting "DDL" in your audio control panel will have absolutely NO EFFECT on games unless the games support the audio format.

Let me do some research on your audio CODEC but I'm still thinking the problem lies with the games audio sourcing.

 

[palladin9479]

Ok just got done looking up your audio CODEC and there could be a few solutions.

First what drivers do you have loaded, were they off the motherboard's CD or did you go to Realtek and get it from them.

http://www.realtek.com/downloads/downloadsView.aspx?Langid=1&PNid=14&PFid=24&Level=4&Conn=3&DownTypeID=3&GetDown=false

I would trust them directly from realtek as it should have all the options and formats enabled by default.

Also what is your default setting under windows sound playback?

Control Panel -> Sound -> Playback Tab -> Digital Output -> Properties -> Advanced

Should be a list of multichannel settings. If it only shows 2-channel settings then your card doesn't support creating multichannel digital I/O streams on it's own. At this point it's entirely up to your game to send it's signal in Dolby / DTS / WMA Pro or whatever format your card and receiver support. If the game doesn't use any of the supported formats then your stuck using the RCA cables or using 2-channel PCM then having your stereo DSP's do the environmental processing. There is also software that intercepts DirectSound calls and encodes it from 5.1 PCM to 5.1 AC3 or DTS. Realktek use's 3D SoundBack and it's available on their driver website.

Also are you using Windows 7 or Windows Vista? This is an issue because as of Vista Microsoft is forcing everyone to use the universal windows audio control rather then letting programs directly talk to hardware. This could be an issue if your game tries to speak EAX and doesn't know to translate it through the audio center first.

 

[gamerk316]

^^ Paladin, his chipset has DDL support, so 5.1 via SPDIF shouldn't be a problem. DDL does NOTHING but convert a 5.1 PCM stream to Dolby format, so as long as the game can output standard 5.1, he should have no troubled getting 5.1 audio via SPDIF.

Though you MAY have stumbled onto the root problem: What games are you trying to send 5.1 from? Under the new audio architecture [starting with Vista], Directsound is a 2.0 software API. If the game is old enough, you will not be able to output 5.1 using any connection type. [I believe Realtek has a seperate "3d soundback" driver that fixes this though...]. This shouldn't be affecting any modern games though, but it could be part of the problem...

 

[alto123]

Click on Start>Control Panel>Hardware and Sound>Sound.

tell me what each device is listed under the playback tab and which is set as default (with the little green check mark).

erly

Under playback tab - Speakers, Realtek Digital Output, Realtek Digital Output(Optical) is listed and Realtek Digital Output(Optical) is with a green tick mark.