[x3d-public] Sound v4 Recommendations - Splitter/Merger/Selector

[Brutzman, Donald (Don) (CIV)]

Thanos:  Doug Sanden (gpugroup, FreeWRL implementer) has made a number of
recommendations on x3d-public mailing list regarding X3D 4.0 Sound
component.

*	X3D4 Architecture, clause 16 Sound component
*
https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-DIS/Part01/
components/sound.html

 

As discussed, am hoping you (and perhaps Efi) can make time to look at them.
Our driving factor is correctly achieving full compliance with 

*	W3C Web Audio API
*	https://www.w3.org/TR/webaudio

 

Doug: thanks for pointing out alternatives whenever our design does not
closely/exactly match the Web Audio API.  That is key and a deciding factor,
since our design goal is to be able to create directly corresponding audio
graphs for each.  At some future point, I expect to demonstrate this by
creating XSLT stylesheets that convert X3D audio graphs to simple ASCII-text
trees (similar to HAnim outputs) and also JavaScript source with matching
Web Audio class invocations.

 

Suggested group approach: first triage and then refine each suggested
change.  Categories:

 

a.	Essential. Necessary change for final X3D 4.0 to correctly support
Web Audio API Recommendation, completing Draft International Specification
(DIS) review corrections.
b.	Next.  Important recommended change for browser implementers and
follow-on X3D 4.1 specification.
c.	Future.  Informational, deserving of further extensibility work
through implementation and evaluation.

 

Am hoping we can have all recommendations and reactions posted and ready for
X3D Working Group meeting on Friday March 3.  Please advise if you think
that is possible - thanks for your continuing careful scrutiny.

 

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 https://
faculty.nps.edu/brutzman

 

From: x3d-public <x3d-public-bounces at web3d.org> On Behalf Of GPU Group
Sent: Thursday, February 16, 2023 6:45 AM
To: X3D Graphics public mailing list <x3d-public at web3d.org>
Subject: [x3d-public] Sound v4 Recommendations - Splitter/Merger/Selector

 

Recommendations:

1. remove outputs field from ChannelSplitter

2. add 2 fields to ChannelMerger

MFInt32 indxSrc [in/out]

MFInt32 indxDst [in/out]

3. remove node ChannelSelector from specifications

 

Explanation:

Merger will get is Splitter channels through its children field, and the
children are in the order of indxSrc[i[, so when making connections, Merger
iterates over indxSrc[i], and for each one renders the Merger.children[i],
and communicates indirectly with splitter (through a stack/state variable)
which of its outputs (or srcIndex) to connect to splitters most immediate
parent. 

If there aren't enough .children for all the indxSrc, the last child is
repeated/re-used.

I have it working in an example scene

https://freewrl.sourceforge.io/tests/16_Sound/SplitChannels6_children.x3d
<https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Ffreewrl.s
ourceforge.io%2Ftests%2F16_Sound%2FSplitChannels6_children.x3d&data=05%7C01%
7Cbrutzman%40nps.edu%7C5c43bc95adce4c669b0208db102c8b30%7C6d936231a51740ea91
99f7578963378e%7C0%7C0%7C638121555752983083%7CUnknown%7CTWFpbGZsb3d8eyJWIjoi
MC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&s
data=lOjmUJIGy6qCzAYK19LeQpyaIK7m21hbYL14bFaypn8%3D&reserved=0>  

The indxDst, indxSrc are a 2-tuple, and there should be equal numbers of
them,  the recommended field names a) are similar to Web Audio srcIndx,
dstIndx so familiar to those working with web audio b) re-arranged to make
them alphabetical-order sequential in the specs, so its more obvious they go
together.

The design eliminates the need for a separate ChannelSelector node (which is
ill-defined, and web audio doesn't have one) -- the same kind of selections
can be done with indxDst, indxSrc in ChannelMerger.

 

-Doug

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://web3d.org/pipermail/x3d-public_web3d.org/attachments/20230216/c301577e/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 5353 bytes
Desc: not available
URL: <http://web3d.org/pipermail/x3d-public_web3d.org/attachments/20230216/c301577e/attachment-0001.p7s>