SOURCE ENGINE AUDIO :: Head-Related Transfer Functions

[WildCat]

Edit (12 Jan 2017):

Valve has acquired Impulsonic. Impulsonic are the creators of Phonon 3D, which is the 3D audio system that Valve used to provide HRTF in CS:GO. I think this is great news because it means that Valve are taking 3D audio seriously and I think that we will see HRTF being introduced into other Valve games (especially any future VR titles). I also think that it could mean that the HRTF feature in CS:GO will continue to get improvements and updates.

- Screenshot[imgur.com] (announcement email I got from Impulsonic)
- Impulsonic's website[www.impulsonic.com]

Edit (8 Dec 2016):

We are truly blessed this day. Praise be unto Lord Gaben for He has lavished the faithful patrons of CS:GO with the everlasting joy of HRTFs. Praise be! Praise be.

CS:GO Blog: Holiday Season never sounded so good.

Original post (2 Oct 2013; last edited 9 Jan 2016):

Please consider adding head-related transfer functions[en.wikipedia.org] (HRTF) to the headphone mix in Source Engine games.

By implementing HRTFs, headphone users can enjoy a sound field that is much more natural, realistic and three dimensional. You'll be able to perceive the location of a sound coming from any arbitrary direction including behind, above and below.

With consumer-level head-mounted displays coming in the near future, the desire for true 3D audio with headphones will be even greater than it already is. The immersive, 3D visuals of VR deserve to be supplemented by similarly sophisticated audio.

I realize that implementing HRTFs may not be a trivial exercise. Therefore, as an alternative to doing this yourselves, I suggest integrating one of the existing solutions that supports HRTFs. I know of six options. The first two are both implementations of the OpenAL API:

• Rapture3D[blueripplesound.com]
  
• OpenAL Soft[kcat.strangesoft.net]

One of the advantages of OpenAL is that end-users can swap the implementation of OpenAL that a game uses. This means that merely implementing support for OpenAL will allow enthusiasts like myself to use Rapture3D or OpenAL Soft in Source games.

The other four options are:

• RealSpace 3D[realspace3daudio.com]
  
• Oculus Spatializer (Oculus Audio SDK)[developer.oculus.com]
  
• 3Dception[twobigears.com]
  
• Phonon 3D[www.impulsonic.com]

Video Demonstrations

For those not familiar with HRTFs and how they improve audio in games, have a listen to these demo videos. Note: You need to be using headphones.

Rapture3D:

http://www.youtube.com/watch?v=KKkI0W0_2Qg
http://www.youtube.com/watch?v=f4PJ68LHU-I
http://www.youtube.com/watch?v=zx4k8qewC_8
http://www.youtube.com/watch?v=iikd_hucZbY
http://www.youtube.com/watch?v=lqqiIR017SQ

RealSpace 3D:

http://www.youtube.com/watch?v=s3eOuqAmLAA

Interactive Demonstration

I created this interactive demo in Unity to show off RealSpace 3D.

• RealSpace 3D Audio v0.10.6 Demo[matthewkerswill.com] (148 MB)

Further reading

• I Want HRTFs In My Games![matthewkerswill.com]
  - A non-game-specific article I wrote on my personal website.
  
  
• OpenAL Audio for Source Engine
  - My suggestion thread on the old Steam forums that dates back to 2010.

[2point4]

OpenAL is already in the Source engine. You just need to be using Linux or OSX. I'd say you're out of luck when it comes to the Windows Source engine, given Valve's dwindling support of anything Windows related. But possibly when Source 2 comes out all platforms will have OpenAL.

So is there any reason you can't already do what you've described here by playing Valve games on Linux or OSX?

[WildCat]

Originally posted by 2point4:

OpenAL is already in the Source engine. You just need to be using Linux or OSX. I'd say you're out of luck when it comes to the Windows Source engine, given Valve's dwindling support of anything Windows related. But possibly when Source 2 comes out all platforms will have OpenAL.

So is there any reason you can't already do what you've described here by playing Valve games on Linux or OSX?

OSX is not an option because it cannot be installed on my existing hardware. As for Linux, I have considered trying it out but I haven't got around to it yet. Perhaps I'll install it on a USB stick to test it.

That said, Rapture3D doesn't support Linux at the moment so I'd have to go with OpenAL Soft, which has good HRTFs but I've been spoiled by Rapture3D's excellent HRTFs and I'd obviously prefer to use that. (EDIT: I've grown more fond of OpenAL Soft since posting this.)

If Valve have already got OpenAL support in the Source engine for OSX and Linux, then they really should enable it as an option for Windows as well.

By the way, I wouldn't describe Valve's support for Windows as "dwindling". Windows 7 64-bit alone is used by more than 50% of Steam users. It wouldn't make sense to not put full effort into Windows support.

[2point4]

I agree that they should enable it for the Windows Source engine. But it's been almost (more than?) two years since it was added for OSX and not even a hint of it has surfaced for the Windows version.

As far as Valve's Windows support, it is clearly dwindling. Lots of bugs exist in the Windows Steam client that have long been unaddressed. And with every new feature release more are piling up. And with beta client after beta client still not addressing them but focusing more on OSX and Linux fixes I think the writing is on the wall. And you're right...it doesn't make any sense. But Windows 8 still remains an unsupported operating system by Valve. Look at the About page. It's just XP (which will soon be unsupported by even Microsoft), Vista and 7. And 8 has been out for over a year if you go by its RTM release. 8.1 has already RTM'd and GA is approaching quickly. I'm going to guess that it also will remain unsupported.

But like I said, Source 2 might offer you a solution. Given Valve's hard stance against all things Microsoft, I predict that Source 2 will be OpenGL only. And with that they'll can all things DirectX related. OpenAL is really the only open audio solution to go with now, even though its progression remains slow and held back by its curator, Creative Labs. Maybe Valve will hop on to the development train with OpenAL like how they've done with OpenGL.

[WildCat]

Originally posted by 2point4:

OpenAL is already in the Source engine. You just need to be using Linux or OSX.

I recently installed Ubuntu 13.04 64-bit in a new partition on my hard drive specifically for testing this. After a lot of fiddling around and tweaking, I'm starting to doubt that Source really uses OpenAL on Linux. I made some comments on a Reddit thread related to this subject and you can find more details about my experiments there...

• Main post on Reddit
  
• Permalink to my specific comment thread on the above post

Unless someone can prove to me that Source is using OpenAL on Linux and explain to me why it ignores my modifications to ~/.alsoftrc, then I'm going to remain sceptical.


That aside...
Even if I was able to get HRTFs in Source on Linux via OpenAL, it wouldn't be a solution to my suggestion. I still would really love to see Valve implementing a solution that enables HRTFs for all users on all platforms.

[rim6o]

+1!

Linux is my only system and I can confirm HRTF is not working on Linux for Source games. I've tested it with TF2, Portal and HL2 demo.

Simple stereo sound in 2013... Well, it's like seeing 3.5" FDDs in 2003. Not exactly something to be proud of.

[rim6o]

So, here's the thing. We can ♥♥♥♥♥ about devs being backwards by a decade in terms of audio all day long and it won't change anything, even though we're right. Anyone has an idea on how to get some attention to the subject?

My first idea was to contact Phoronix and some linux gaming website to ask for coverage on a subject of 'linux having an advantage in audio over Windows'. This should click but linux popularity is low and it would yield much better results if we could get some attention for HRTF on Windows/in general.

Does anyone know someone writing for some gaming website or maintaining a blog on gaming? I could contact few gaming video bloggers at youtube but I don't have a google+ account and I don't intend to create one. I imagine a coverage by e.g. The Cynical Brit could do more than our year-long writing on some obscure forums like these :)

[rojimboo]

What is your opinion on enabling DirectSound3D, 5.1/7.1 and using Dolby Headphone?

The reason why I'm asking is that currently my setup (Sennheiser HD598 with Asus Xonar Essence STX) has really only these possibilities for decent 3d sound in Source games.

The trick is to enable legacy sound in Source Engine games via the console/cfg command
snd_legacy_surround 1

In CS:GO I hear a definite improvement in spatial and positional sound doing this. Asus' Dolby Headphone always works better the more accurate positional sound there is to work with, to be honest it sounds quite dire when transforming stereo sound, but with these settings it is quite accurate.

I know this works for Portal 2 too, as I made a thread about it back in the day once upon a time xd

http://forums.steampowered.com/forums/showthread.php?t=2608992

But I remember there being some sort of workaround/issue with TF2, that I can't be bothered to remember.

In any case, it is hardly ideal, as on Windows Vista upwards we need a wrapper to get those DirectSound3d calls into Openal. So basically Creative Alchemy, or Asus' GX mode, which I use now, though it can be glitchy on some games.

TL DR; I fully support your call for better support(xd) for better 3D sound. I'm just afraid that the Valve devs might be like "but look there is the legacy surround thingie you can use". Which isn't ideal but works fairly well.

[rim6o]

Listen to this. It's a Source engine game. The simplistic stereo panningis so evident it hurts
https://www.youtube.com/watch?feature=player_detailpage&v=7TrcVxszkD0#t=316

From 05:20

[WildCat]

Originally posted by rim6o:

So, here's the thing. We can ♥♥♥♥♥ about devs being backwards by a decade in terms of audio all day long and it won't change anything, even though we're right. Anyone has an idea on how to get some attention to the subject?

My first idea was to contact Phoronix and some linux gaming website to ask for coverage on a subject of 'linux having an advantage in audio over Windows'. This should click but linux popularity is low and it would yield much better results if we could get some attention for HRTF on Windows/in general.

I have thought of emailing someone at Valve directly to ask them about this subject. The problem is that I don't know who to email. I've looked at their People page on their website and searched through it for the words "audio" and "sound" but all the relevant people don't have publicly-available email addresses.

With regards to the whole industry (as opposed to just looking at Valve), I've considered emailing popular audio pipeline solution developers like Audiokinetic (for Wwise) and Firelight Technologies (for FMOD) but I just haven't got around to that yet.

Originally posted by rim6o:

Does anyone know someone writing for some gaming website or maintaining a blog on gaming? I could contact few gaming video bloggers at youtube but I don't have a google+ account and I don't intend to create one. I imagine a coverage by e.g. The Cynical Brit could do more than our year-long writing on some obscure forums like these :)

I'm not really familiar with The Cynical Brit. I've watched maybe one or two of his videos so I don't really know if he's technically-minded enough to explain this subject. What do you think? In my opinion, it's important not to spread any more misconceptions about this subject because there are already enough of those floating around.


----------------------------------------

Originally posted by rojimboo:

What is your opinion on enabling DirectSound3D, 5.1/7.1 and using Dolby Headphone?

The reason why I'm asking is that currently my setup (Sennheiser HD598 with Asus Xonar Essence STX) has really only these possibilities for decent 3d sound in Source games.

To me, Dolby Headphone is one of the worst-sounding headphone surround systems available today. I dislike the way that they simulate the sound of a room with speakers in it. It colours the sound too much, in my opinion. (I also talk briefly about this in this blog post[matthewkerswill.com].)

Also, I wouldn't say that Dolby Headphone provides "3D sound". Even a proper 5.1 or 7.1 speaker setup doesn't provide 3D sound. If the audio that you hear doesn't provide elevation information, it can only really be considered 2D sound. Most games only provide 1D sound in their default headphone mixes: a basic linear gradient from 100% left to 100% right.

Originally posted by rojimboo:

The trick is to enable legacy sound in Source Engine games via the console/cfg command
snd_legacy_surround 1

In CS:GO I hear a definite improvement in spatial and positional sound doing this. Asus' Dolby Headphone always works better the more accurate positional sound there is to work with, to be honest it sounds quite dire when transforming stereo sound, but with these settings it is quite accurate.

I decided to test this again with CS:GO to refresh my memory. My conclusion was that Dolby Headphone wasn't offering better positional accuracy with snd_legacy_surround 1 and GX mode enabled.

In the driver software, I had it set to 8 channels with Headphone output. Dolby Headphone enabled. In CS:GO, I had 5.1 speakers selected. I found that:

• With snd_legacy_surround 0 and GX mode disabled, it sounded decent.
  
• With snd_legacy_surround 1 and GX mode disabled, it sounded completely wrong.
  
• With snd_legacy_surround 1 and GX mode enabled, it sound just about the same as the first case (except that sounds coming from directly in front seemed to be softer than anywhere else).

Originally posted by rojimboo:

I'm just afraid that the Valve devs might be like "but look there is the legacy surround thingie you can use". Which isn't ideal but works fairly well.

I doubt Valve's devs would take that stance on this subject. Rather, I think that they just don't know about HRTFs or are not personally interested enough in them to prioritize that research and development. Perhaps they're not interested in pushing any of their technology forward anymore.

They seemed to be more interested in cutting edge technology when they were making Half-Life 2. I remember their tech demos that showed off their revolutionary new physics simulations, facial animation and mind-blowing water reflections and refractions. Not long after they came out with Lost Coast to show off their new HDR system.

Nowadays, the Source engine is so old and rusty in both the graphics and sound department. They haven't put anything new into it for ages. In fact, they're not even using all of the existing features for CS:GO. For example, they can't even be bothered to author normal maps for the majority of textures in that game. It's really quite lame.

[rojimboo]

You don't notice elevation sounds in CS:GO with snd_legacy_surround = 1 and GX mode? In a map like Dust2? Because I do. Oh well, it's pretty subjective but I think it sounds better though and will continue using it.

By the way, offtopic sorry, but what do you think about TrueAudio from AMD? A DSP on the graphics card isn't in itself remarkable, but more the fact that there is now a significant player on the PC field pushing for 3D sound. The fact that they are working with and developing plugins for FMOD and Wwise, and the fact that the upcoming Thief game will utilise it, all has me somewhat excited xd.

http://www.anandtech.com/show/7370/amd-announces-trueaudio-technology-for-upcoming-gpus

Now I wish I had gone AMD :(

[Mr Keefy]

wawawewa i amvery excite

ITs actually takes the real positional data from the game engine exactly where the sound is produced ratehr than an approximation with algorithm trickery like CMSS 3D and ASUS GX or whatever they are. Although CMSS3D in my experience is pretty good, much smoother transition than regular stereo. I miss it since upgrading my CPU and board, of which does not have PCI slots for my X-fi

In my opnion Sound is just as important as graphic to create atmosphere, imagine the film Psycho without that violin screech in the shower scene.

[rim6o]

"The plan"
IMO writing to someone at Valve doesn't make much sense. At least one audio guy at Valve knows about HRTF and is in direct contact with the whole dev team. Case closed, as far as I'm concerned :)

What I think is:
1. I thik we need to get the attention by using creators of popular content.
2. We shouldn't limit 'the cause' to neither Source engine nor Windows platform.

Here's my idea. As you may know Amnesia is not only a great game series but also one driven by the phenomena of million-views gameplay videos. What if we get one of the creators of popular Amnesia videos to do a >proper< coverage on HRTF?


The Cynical Brit:
IF he agrees to do a video on HRTF, I think we could talk to him prior to the venue to clear up any misunderstandings on HRTF and positional audio. I doubt he would 'go ignorant' :) BTW, AFAIK he took part in promoting WFTO Kickstarter.


Other stuff:
A brief infographic on HRTF.
A title page for videos presenting HRTF in action.

[WildCat]

Originally posted by rojimboo:

By the way, offtopic sorry, but what do you think about TrueAudio from AMD? A DSP on the graphics card isn't in itself remarkable, but more the fact that there is now a significant player on the PC field pushing for 3D sound. The fact that they are working with and developing plugins for FMOD and Wwise, and the fact that the upcoming Thief game will utilise it, all has me somewhat excited xd.

http://www.anandtech.com/show/7370/amd-announces-trueaudio-technology-for-upcoming-gpus

I am somewhat interested in TrueAudio but, at the moment, they haven't provided any detailed specifications so I'm not yet convinced that it will make any particularly useful impact on gaming audio. I doubt I'll be switching to an AMD graphics card just for TrueAudio.

GenAudio's AstoundSound 3D RTI was the most interesting thing to be mentioned at the announcement of TrueAudio. Based one what they say it can do, it seems like the kind of thing I'd want developers to implement. However, I'm also skeptical of this product because they haven't released any decent demonstrations of it. The only demonstration that I've heard has been pretty unimpressive.

Originally posted by rim6o:

Here's my idea. As you may know Amnesia is not only a great game series but also one driven by the phenomena of million-views gameplay videos. What if we get one of the creators of popular Amnesia videos to do a >proper< coverage on HRTF?

The Cynical Brit:
IF he agrees to do a video on HRTF, I think we could talk to him prior to the venue to clear up any misunderstandings on HRTF and positional audio. I doubt he would 'go ignorant' :) BTW, AFAIK he took part in promoting WFTO Kickstarter.


Other stuff:
A brief infographic on HRTF.
A title page for videos presenting HRTF in action.

I'm beginning to write a Guide on Steam Community to explain how to get HRTFs working in Amnesia: The Dark Descent on Windows and I'll use it as a template for creating additional Guides for other games as well. I'll post a link when it's done. I'm going to make it as clear and detailed as possible and it will hopefully be a useful resource to send to whomever you want to try and convince to promote 3D audio.

[WildCat]

Here are the guides:

Enable 3D Surround Sound for Stereo Headphones for Amnesia: The Dark Descent
Enable 3D Surround Sound for Stereo Headphones for Amnesia: A Machine for Pigs

Please give it a thumbs up rating! :D

Other guides coming soon.

[rim6o]

Originally posted by WildCat:

Here are the guides:

Enable 3D Surround Sound for Stereo Headphones for Amnesia: The Dark Descent
Enable 3D Surround Sound for Stereo Headphones for Amnesia: A Machine for Pigs

Please give it a thumbs up rating! :D

Other guides coming soon.

Do you think you could post instructions for linux as well. I wasn't able to enable HRTF for AAMFP.
my notes:

cp '/home/hhh/.local/share/Steam/SteamApps/common/Machine for Pigs/lib/libopenal.so.1' '/home/hhh/.local/share/Steam/SteamApps/common/Machine for Pigs/lib/libopenal.so.1.bak'
cp /usr/lib/libopenal.so.1.15.1 '/home/hhh/.local/share/Steam/SteamApps/common/Machine for Pigs/lib/libopenal.so.1'

Regarding spreading the word:
1. Could you elaborate on how Dolby Headphone or CMSS3D are inferior to OpenAL HRTF?
2. Is '3D surround sound' the correct term for what HRTF provides? It would be beneficial to diferentiate from gimmicks while discussing HRTF.