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Hi all.

From: redman <redman@redman.demon.nl>
Date: Tue, 20 Nov 2012 19:29:04 +0100
Message-ID: <50ABCBF0.3010306@redman.demon.nl>
To: public-audio@w3.org
Hello everyone.

I've recently become involved in a web audio API project (so this is 
directed at the people involved in defining this).
It's a reasonably simple affair with a couple of synths and a drumcomputer.
But i have run into some strange behaviour from a musical perspective.
The problem is that apparently when you use  .Value =   to set an 
AudioParam value it is heavily (sloooowly) interpolated.
Now i understand why you do this but it doesn't make sense to do it all 
the time and it certainly doesn't make sense to not be able to change 
the speed of this interpolator.

One of the problems that occur is when setting the frequency of an 
oscillator.
What happens is that the frequency will change but it will not be 
instantaneously, so the frequency slides from one value to the next.
And that is pretty useless as the change is way too slow for most 
situations.
What does work is just scheduling the change, but this is not always 
wanted and seems counter-intuitive. When i set a value i expect it to 
just change.
What would be useful is some way to either disable this behavior or to 
be able to control the speed of interpolation.
In the case of oscillator frequency it actually represents an optional 
function usually called Portamento.
And of course in real synths this function can be switched off or 
tweaked to fit the sound designers intention.
But in the implementation (chrome) that i use it is neither optional nor 
configurable which is a bad thing and actually unwanted most of the time.
If you think it's great because getting rid of clicks gave you a free 
portamento think again! :)
It is just not always appropriate to have this behaviour and fixing it 
globally is like looking at the world through a hammer. Everything 
becomes a nail.

So i hope you can fix that in the future. Not all modulations are meant 
to be used with smooth continuous signals!
Preferably there would be separate functions to have the input either 
interpolated or not. That way you can simultaneously input values that 
you want to be interpolated and values that you do not want to become 
interpolated and they would be mixed together down the path before 
feeding the actual audio algorithm.
Also, there may be a future need to decide the actual interpolation algo 
because not all types of interpolation work equally well on all 
parameter types.
But first things first :) make it so that it doesn't stand in the way of 
building great synths.

greets,
aka.
Received on Wednesday, 21 November 2012 13:12:36 UTC

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