[x3d-public] audio meeting 14 April 2021: W3C Audio,

[Don Brutzman]

Attendees: Efi Lakka, Thanos Malamos, Maria Papadaki, Dick Puk, Don Brutzman

1. Opportunity.  We discussed interesting questions in W3C Audio group:

On 4/8/2021 10:27 AM, Raymond Toy wrote:
> Subject: Re: [Agenda] WG/CG Telecon Thurs Apr 8 9:00 am PDT
> # V2
> 
>   * New issues 

https://github.com/WebAudio/web-audio-api/issues/122

>       o Allow PannerNodes to have Volume <
>           + Raymond: They want sources to have spatial extent.
>           + Paul: Wonder how cold fusion with a source and walls works?
>           + Raymond: Some kind of ray-tracing?
>           + Paul:  Yes.
>           + Paul; Wonder if Unity has something like this?
>           + Paul: Looking at Unity docs for audio source.  Similar to what we do.  Looks like a point source.
>           + Raymond: Maybe ask if OP knows of any system that does this?  Then we can start looking.
>           + Paul: Unreal engine has a shape and inner radius parameters, so there is some kind of "volume" concept.

It "sounds like" they are interested in 3D spatialization, possibly even acoustics, so this may be a good opportunity for us to contribute.

Thanos and Don will attend their weekly meeting tomorrow and ask for more discussion on this topic - what do they need?  What are they hoping to accomplish?

We can then consider how to offer X3D progress on audio 3D spatialization (mature and implemented) and 3D acoustic propagation/attenuation (well defined but not yet implemented).

Efi will consider posting something - list of capabilities perhaps - and we can attend in the next 1-2 weeks.

Key figure:

* Figure 16.4 — SpatialSound Panning Gain Relationships for viewer (or ListenerPointSource)
   https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD/Part01/components/sound.html#f-SpatialSoundPanningGainRelationships

TODO spec editors: change "viewer" to "listener" in this caption, in order to match figure.

TODO spec editors: Ensure image with is 100% (rather than very large side)

TODO image improvement: Efi will add a dot where the arrow exits the cone on the right-hand side.

TODO: create an X3D Model to match this diagram, would be very interesting and helpful.

---

2. X3D4 Specification comments

ISO Ballot deadline X3D4 Architecture is only a weeks away.  Web3D Consortium is able to post comments on X3D4 (our own submission).

There are several "light-blue markups" in the X3D4 Sound Component (committee draft) that should be reflected in our Mantis issue tracker.  We will look at these.

* https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD/Part01/components/sound.html

a. "Format=AAC, container=MP4 TODO: reference"

answer from Thanos:

"Format=AAC, container=MPEG-2"

- ISO/IEC 13818-7, MPEG-2 Audio

- ISO/IEC 14496-3, MPEG-4 Audio

- container ISO/IEC 14496-14 for MP4

b. WebRTC stream identification issue:

16.4.19 StreamAudioDestination and
16.4.20 StreamAudioSource

StreamAudioDestination : X3DSoundDestinationNode {
[...]
MFString [in,out] streamIdentifier      []
[...]

The /streamIdentifier/ field conforms to requirements of W3C Media Capture and Streams [W3C-Media].

Thanos will investigate further.

Am wondering if this might be a url?

Once we have X3DOM initial implementation published, we should post the issue to W3C Audio Group.  Meanwhile we should ensure that the Web3D Mantis issue covers this.

Any other issues to note?  Efi agreed to check (yet again) to ensure that the published interfaces match the implementation that has been submitted for X3DOM build integration.

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3. Interesting book by Boris Smus

============================
https://webaudioapi.com/book

"I wrote a short book about the Web Audio API called "Web Audio API: Advanced Sound for Games and Interactive Apps".

This book is what I wish existed when I started experimenting with the API in 2011. It is intended to be a springboard for web developers like I was, with little to no digital-audio expertise. It contains the things I learned from about a year of studying digital audio processing, having conversations with audio experts, and experimenting with the API.

O'Reilly published it, Amazon sold it, and I released it for free under the CC license. It's available in a few formats:
HTML
PDF
MOBI
EPUB"
============================

https://webaudioapi.com/book/Web_Audio_API_Boris_Smus_html/ch06.html#fig26
Figure 6-3. A diagram of panners and the listener in 2D space

This is an interesting diagram but seems a little misdrawn, since it shows chords rather than cones.

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4. Implementation progress for X3DOM... we rang the bell again:

Hello X3DOM! Wondering if anything is happening?  Everybody OK out there?

* https://github.com/x3dom/x3dom

Should Efi submit a pull request (PR) ?

* https://github.com/x3dom/x3dom/pulls

On 4/7/2021 10:38 AM, Don Brutzman wrote:
> Hello X3DOM wizards, we hope everyone is well and staying safe no matter what happens.
> 
> Am happy to report that Efi Lakka has done much work on implementing her revisions for X3DOM to support the significantly updated X3D4 Sound Component.  This work integrates the W3C Audio API.
> 
> [1] Efi link to follow... she plans to put it at
>     https://github.com/efilakka
> 
> [2] X3D4 WD3 annotated Sound Component
>     http://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD/Part01/components/sound.html
> 
> [3] X3D4 CD (pristine) Sound Component
>     http://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-WD3/Part01/components/sound.html
> 
> [4] W3C Web Audio API
>     https://www.w3.org/TR/webaudio/
> 
> [5] Web3D 2020 Conference: sound tutorial
>     https://web3d.siggraph.org/x3d-audio-graphs-acoustic-properties-3d-spatial-sound
> 
> [5] Current demos
>     https://medialab.hmu.gr/minipages/x3domAudio
> 
> Wondering, should she perform a pull request? She is further wondering about next steps... Please advise.
> 
> p.s. If a special demo session is helpful, then we are happy to do that.  If convenient, our weekly meeting is Wednesday 1000 Pacific.

Once an X3DOM build is in motion, we will suggest support in X_ITE as well.

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So many good things to do... lots of anticipation.

Today's imponderable question: "gee i wonder who is going to make insane amounts of money on 3D audio podcasts someday??"  Show of hands please...

Have fun with X3D4 Audio!!  8)

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman