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Re: References for helping me to implement dynamic range compression

From: Marcus Geelnard <mage@opera.com>
Date: Thu, 29 Aug 2013 14:15:37 +0200
Message-ID: <521F3B69.2020008@opera.com>
To: s p <sebpiq@gmail.com>
CC: "public-audio@w3.org" <public-audio@w3.org>
2013-08-29 12:33, s p skrev:
> Hi!
> I am currently implementing DynamicsCompressorNode in 
> node-web-audio-api (https://github.com/sebpiq/node-web-audio-api).
> I have been looking for some implementation that I could copy, but 
> until now, I have found mostly research papers and experimental 
> implementations of compression.
> I cannot read C++ :( , otherwise I would read blink or gecko source code.
> If the people who implemented it are reading this message ... any 
> reference to an article or site that you used for the implementation?
> For example, how do you calculate the input level? RMS on a block?
> Any pointer would be welcome.

Your case is a very good example of why such behavior should be 
specified normatively in the specification (i.e. the C++ source code of 
a particular implementation can not act as a replacement for a proper 
specification). The underspecified DynamicsCompressorNode is a known 
issue, see: https://www.w3.org/Bugs/Public/show_bug.cgi?id=17362 (which 
has not yet been addressed).

I think/hope that this group will focus more on fixing spec issues soon 
(once we have the data race issue out of the way).


Marcus Geelnard
Technical Lead, Mobile Infrastructure
Opera Software
Received on Thursday, 29 August 2013 12:16:26 UTC

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