ISSUE-69: (Bugzilla 17403) Linear convolution effect is defined by Wikipedia

LinearConvolution

(Bugzilla 17403) Linear convolution effect is defined by Wikipedia

State:
CLOSED
Product:
Web Audio API
Raised by:
Philip Jägenstedt
Opened on:
2012-05-16
Description:
https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#ConvolverNode

links to

https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#Convolution-section

links to

http://en.wikipedia.org/wiki/Convolution

The definition should be in the specification itself. A problem that is not addressed at all is how phase/latency depends on the length of the convolution buffer. In other words, it must be defined exactly how each sample value is calculated from the the input signal and the impulse response buffer.
Related Actions Items:
No related actions
Related emails:
  1. [web-audio-api] (LinearConvolution): Linear convolution effect is defined by Wikipedia (#125) (from notifications@github.com on 2013-09-11)
  2. Re: third public Working Draft of the Web Audio API available (from tmichel@w3.org on 2012-08-02)
  3. Re: State of issues as of 2012-05-30 (from philipj@opera.com on 2012-06-01)
  4. Re: Audio-ISSUE-69 (LinearConvolution): Linear convolution effect is defined by Wikipedia [Web Audio API] (from philipj@opera.com on 2012-06-01)
  5. State of issues as of 2012-05-30 (from olivier.thereaux@bbc.co.uk on 2012-05-30)
  6. Re: Audio-ISSUE-69 (LinearConvolution): Linear convolution effect is defined by Wikipedia [Web Audio API] (from olivier.thereaux@bbc.co.uk on 2012-05-25)
  7. Re: Summary of issues (from crogers@google.com on 2012-05-22)
  8. Summary of issues (from mage@opera.com on 2012-05-22)
  9. Audio-ISSUE-69 (LinearConvolution): Linear convolution effect is defined by Wikipedia [Web Audio API] (from sysbot+tracker@w3.org on 2012-05-16)

Related notes:

I believe the operation "linear convolution" is a sufficiently well-known and well-defined operation in mathematics that no further explanation is required, anymore than the definition of a cos() function. It is defined in many texts on math/DSP.

I will add an "informative" link to a page which can help guide implementors to practically implement this well-defined mathematical operation. I am happy also to point to working, cross-platform, well-optimized code having a non-restrictive license. I can also point to an alternate implementation "Freeverb":
http://freeverb3.sourceforge.net/

FIXED:
https://dvcs.w3.org/hg/audio/rev/7865f8b76f19

Chris Rogers, 25 May 2012, 01:03:01

Setting status as "Pending Review"

Olivier Thereaux, 25 May 2012, 10:38:48

[MikeSmith]: https://www.w3.org/Bugs/Public/show_bug.cgi?id=17403

5 Jun 2012, 13:04:02

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Matthew Paradis <matthew.paradis@bbc.co.uk>, Raymond Toy <rtoy@google.com>, Chairs, Chris Lilley <chris@w3.org>, Staff Contact
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