AeonWave: An Open-Source Audio Engine Akin To Microsoft's XAudio2 / Apple CoreAudio

[phoronix]

Phoronix: AeonWave: An Open-Source Audio Engine Akin To Microsoft's XAudio2 / Apple CoreAudio

An open-source audio initiative that's been in development for years but flying under our radar until its lead developer chimed in is AeonWave, which supports Windows and Linux systems while being inspired by Microsoft XAudio and Apple's CoreAudio...

http://www.phoronix.com/scan.php?page=news_item&px=AeonWave-Open-Audio-Engine

[shmerl]

Interesting. The site looks like from the late '90s. I didn't quite understand where there source repo is though.

UPDATE: Found it. For some reason the project is called "aax": https://github.com/adalinbv/aax

[SpyroRyder]

What does 4D audio mean to this guy? The 4th dimension was supposed to be time iirc but Disney at least used it to mean 3D plus smell/physical experiences. So what does he mean by it

[cl333r]

What does 4D audio mean to this guy? The 4th dimension was supposed to be time iirc but Disney at least used it to mean 3D plus smell/physical experiences. So what does he mean by it

He literally means the 4th Dimension, he discovered it and implemented an interface to it from software.

[deant]

This is Privoxy 3.0.26 on unknown (192.168.3.1), port 8118, enabled.

Request for blocked URL

Your request for http://adalin.com/ was blocked.
Block reason: Host matches generic block pattern.
See why this block applies

[ehofman]

What does 4D audio mean to this guy? The 4th dimension was supposed to be time iirc but Disney at least used it to mean 3D plus smell/physical experiences. So what does he mean by it

4D means distance induced time-delay in case of AeonWave. You can use it to simulate faster-than sound experiences for instance (albeit without the sonic boom, that has to be added by the client software). Support is added for delayed state changes and delayed arrival at the listener. But it defaults to 3D behavior.

[ehofman]

This is Privoxy 3.0.26 on unknown (192.168.3.1), port 8118, enabled.

Request for blocked URL

Your request for http://adalin.com/ was blocked.
Block reason: Host matches generic block pattern.
See why this block applies

This seems to be something at you side (see the last link)? I've asked the service provider but they don't use blocking of any kind.

[DrYak]

What does 4D audio mean to this guy? The 4th dimension was supposed to be time iirc but Disney at least used it to mean 3D plus smell/physical experiences. So what does he mean by it

Joke aside :

- 4D sound means "adding one more dimensions to 3D sound".
- 3D sound has been abused to describe Surround sound (it's actually on a plane around the listener, so technically it's 2D sound, not 3D)
- so "4D Sound" is what anyone would consider 3D. (i.e.: with an up and down axis extra in adition to around)

- 3D sound has been called this way to distinguish itself from Stereo (Even if it is what anybody would consider 2D: arbitrary position on an horizontal plane surrounding the listener)
- Stereo it self is what every body would consider 1D (single continuous left-right axis).

(- Though someone would argue that even Mono has a dimension (volume) and thus everything adds up to 4D (just for trolling).)


Stereo can be achieved using simply 2 speakers, each playing toward one ear.
Anything above stereo, either requires multiple speakers, or requires much more precise simulation of head transfer function and modelling of the effect of external ear (and real time update based on the head's "virtual position")

(Yes humans have only 2 ears, but sound get distorted differently depending on where it comes from, and we constantly mode our head. This two combined help to pin-point sound source much more precisely than a simple left-right 1D axis)

[M@GOid]

Joke aside :

- 4D sound means "adding one more dimensions to 3D sound".
- 3D sound has been abused to describe Surround sound (it's actually on a plane around the listener, so technically it's 2D sound, not 3D)
- so "4D Sound" is what anyone would consider 3D. (i.e.: with an up and down axis extra in adition to around)

- 3D sound has been called this way to distinguish itself from Stereo (Even if it is what anybody would consider 2D: arbitrary position on an horizontal plane surrounding the listener)
- Stereo it self is what every body would consider 1D (single continuous left-right axis).

(- Though someone would argue that even Mono has a dimension (volume) and thus everything adds up to 4D (just for trolling).)


Stereo can be achieved using simply 2 speakers, each playing toward one ear.
Anything above stereo, either requires multiple speakers, or requires much more precise simulation of head transfer function and modelling of the effect of external ear (and real time update based on the head's "virtual position")

(Yes humans have only 2 ears, but sound get distorted differently depending on where it comes from, and we constantly mode our head. This two combined help to pin-point sound source much more precisely than a simple left-right 1D axis)

Indeed. 5.1 or 7.1 will not cover sounds coming from above or bellow. In Left 4 Dead 2 you can hear very well where a sound comes from, horizontally. But that fall apart very fast when you hear a enemy moaning from a direction, only to discover it is in a different floor from you.

If this guy could give me a sound that can be perceived from above/bellow via headphones, I'm sold.

[DrYak]

If this guy could give me a sound that can be perceived from above/bellow via headphones, I'm sold.

Would require either headphones with cross-shaped disposition of speakers (the same way 7.1 headphones cram speaker array against each ear).
(Definitely achievable given current 5.1/7.1 headphones)

Or would require precise modelling of your external ear (varies between individual) - (maybe taking a a webcam picture of your ear ?)
(Definitely achievable, used to be experimented with back during the Binaural craze to go beyond phase shifts and head-transfer-function modelling.
Just the exact "convert picture of ear into simulation" step hasn't been tackled to my (limited) knowledge)

A fast webcam based tracking of your headphones (i.e.: tracking exactly how your "virtual head" is relative to sound) could help a tiny bit.
(Such head tracking is currently done in non-room-wide VR (like occulus).
There are patent and experiments to do "perfectly accurate" positioning of audio using coarse accelerometers that date back from past VR generations.
Even shit like doing doppler to adjust for your *head* movements - not the joypad ones)

TL;DR: It's definitely doable, the tech is known. And such an architecture as this one that gives lots of filtering and submixing possibilities is definitely the framework in which it's possible to achieve.