[bookishboy]

I hope this isn't a foolish question.  I'm lucky enough to have a laptop that supports Dolby Headphone output, but may upgrade in the next year. Now that I've upgraded my headphones to take advantage of a personal space surround sound experience with games, I'd like to keep using Dolby Headphone mode but it seems that very few computers (and fewer laptops) support it.
 
Does Dolby Headphone decoding require a dedicated chipset solution in the computer, or could it be processed in software? If it could be done via software, why doesn't Dolby seem to offer a paid app to do exactly that? 
 
If I want to output Dolby Headphone mode from a laptop, are my buying choices limited to models which already support it?  Since I own an astro mixamp (which I primarily use with consoles), would this pick up and decode a Dolby Digital signal from a laptop which doesn't natively support Dolby Headphone?

 

[PurpleAngel]

Quote:

I hope this isn't a foolish question.  I'm lucky enough to have a laptop that supports Dolby Headphone output, but may upgrade in the next year. Now that I've upgraded my headphones to take advantage of a personal space surround sound experience with games, I'd like to keep using Dolby Headphone mode but it seems that very few computers (and fewer laptops) support it.
 
Does Dolby Headphone decoding require a dedicated chipset solution in the computer, or could it be processed in software? If it could be done via software, why doesn't Dolby seem to offer a paid app to do exactly that? 
 
If I want to output Dolby Headphone mode from a laptop, are my buying choices limited to models which already support it?  Since I own an Astro mix-amp (which I primarily use with consoles), would this pick up and decode a Dolby Digital signal from a laptop which doesn't natively support Dolby Headphone?

I would guess there is there is some hardware involved in Dolby, Audio processor manufacturers might pay Dolby a small royalty fee for each audio processor they make that includes this Dolby features.
Also any computer or sound card manufacturer might also have to paid a small royalty fee for each device that contains an audio processor that has the Dolby feature, in exchange that manufacturer can use
Dolby's software to distribute with their audio hardware.
If Dolby made their software totally audio processor independent, people would copy and swap Dolby software for free and Dolby would not get any royalty fees.
But I would think Dolby would try to included as much software processing as possible, as a computer's CPU processing power would be far greater then the processing power that an audio chip could do.
For the Astro Mix-Amp to do surround sound connected with optical to the source, that source(s) would need to come with DDL (Dolby Digital Live).
Normally optical (or coaxial) will only carry 2-channel PCM (uncompressed) audio, but DDL can compress up to 7 channels of audio to be sent thru optical (or coaxial) to something like the Mix-amp.
So if a laptop does not come with DDL, your limited to 2-channel thru put with optical.

 

[Mad Lust Envy]

I believe there are software based Dolby Headphone (I believe Foobar and Winamp have DH plugins), but just like Equalizing, hardware is always better. Also, software DH would be limited to those media players, and not as sound devices where other things (like gaming) would have the option.

 

[NamelessPFG]

Quote:

I believe there are software based Dolby Headphone (I believe Foobar and Winamp have DH plugins), but just like Equalizing, hardware is always better. Also, software DH would be limited to those media players, and not as sound devices where other things (like gaming) would have the option.

 
You hit the nail on the head. This is why Dolby Headphone and similar features need to be part of the audio device's drivers; that way, it can be applied to any source, especially games.
 
Note that a lot of audio devices, especially USB ones, do their processing in software (on the CPU) anyway. It's not as ideal as a hardware DSP implementation, but at least you're not limited to use with media players.
 
Also, PurpleAngel is right about the licensing. Dolby Labs wants money for their features; in fact, when the Auzentech X-Fi Prelude released and Daniel_K tweaked the drivers so that Dolby Digital Live also worked on Creative's own X-Fi cards, Dolby Labs was not pleased. They had to sort things out so that newer X-Fi cards had Dolby Digital Live capability bundled while older cards that predated the X-Fi Prelude could gain the functionality for a small fee, to cover the licensing costs.
 
DTS is no different with the licensing and royalties; it's probably why a lot of the affordable headphone surround processors omit DTS decoding support.
 
Oh, and Dolby Digital/AC-3 can only compress six discrete channels into S/PDIF bandwidth. It can, however, matrix two more channels into the discrete ones, sort of like how Dolby Pro Logic II matrixes three extra channels into two discrete ones for sources that only output stereo (most commonly the GCN and Wii).

 

[Mad Lust Envy]

The Xonar U3 is a USB Dolby Headphone device. Is that one software based? You know me and the computer side of DH = no idea.

 

[PurpleAngel]

Quote:

The Xonar U3 is a USB Dolby Headphone device. Is that one software based? You know me and the computer side of DH = no idea.

I think the Asus U3 comes with an audio processor called the UA100?
As the U3 is USB, it can only receive a 2-channel signal, so Dolby Headphone 5.1 surround sound would have to be processed by software/main CPU and then send to the U3.
Or maybe the older Dolby Surround is used to process the audio signal and the U3 takes in the 2-channel signal and expanse it using the older Dolby Surround.
But I'm just making guesses.

 

[Mad Lust Envy]

Well, the sound could be digitally sent to the U3 and processed internally, maybe?

 

[musicreo]

For notebooks I know the Xonar U1 and U3  external USB audio card. Both support Dolby Headphone (up to 7.1), Dolby Pro Logic and  Dolby Digital Live (all software based).
 
 A software that supports Dolby Headphone is Power DVD (it have this feature since 2002).
 
The foobar2000 plug in uses the Dolby Headphone.DLL that comes with Power DVD.

 

[RPGWiZaRD]

Genius Action and I am on a very interesting config to make this happen software wise for the whole system whatever you do and this with absolutely stunning sound quality to it but we still need to get the sound centered correctly in this particular config.
 

 
I tested using the same setup but for movies only using MPC-HC and when I tested "Enemy At The Gates" I got the first shivers even down in my legs that I've never ever experienced before, it sounded THAT good. For this system-wide config it's a little bit tricker but there's like plenty of settings to play around with which may be able to correct it, with default settings the prob is that the center of the soundstage is like a bit in front of left ear.

 

[joachimvhw]

Any information on your project, RPGwizard? Thanks.