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Re: Channel up-mixing / down-mixing, how to compute num channels of connection?

From: Ehsan Akhgari <ehsan.akhgari@gmail.com>
Date: Tue, 16 Jul 2013 17:40:04 -0400
Message-ID: <CANTur_7LJTwDg8L4+epw1hYE_PB0pdewyTq647JY4s_enEwBbg@mail.gmail.com>
To: s p <sebpiq@gmail.com>
Cc: "public-audio@w3.org" <public-audio@w3.org>
The number of channels for each node's output are determined by this
algorithm.  There are some nodes which force this value to a certain value
(for example, PannerNode) but most node types follow this algorithm.

Note that the channelCount for a given node cannot be trusted unless
channelCountMode is "explicit".


On Mon, Jul 15, 2013 at 1:44 PM, s p <sebpiq@gmail.com> wrote:

> Or is it so that the max number of channels from outputs is inferred by
> the number of channels in the buffers received from upstream?
> 2013/7/14 s p <sebpiq@gmail.com>
>> Hi!
>> Reading the chapter "9 - channel up-mixing / down-mixing", from what I
>> understand the number of channels should be computed for each input.
>> However it says :
>> > “max”: computedNumberOfChannels is computed as *[the maximum of the
>> number of channels of all connections]*.
>> So how I understand it is that you actually need the number of channels
>> of each output for computing "computedNumberOfChannels". But I couldn't
>> quite figure out how to compute the number of channels of an ouput. Is the
>> node's raw channelCount?
>> Or did I get it all wrong?
>> Sebastien Piquemal
>> PS : for info, I am in the process of implementing the Web Audio API spec
>> for Node.js (https://github.com/sebpiq/node-web-audio-api).
Received on Tuesday, 16 July 2013 21:41:11 UTC

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