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Re: [Bug 21980] New: WaveTable is highly underspecified

From: Joseph Berkovitz <joe@noteflight.com>
Date: Sat, 11 May 2013 13:38:15 -0400
Cc: "public-audio@w3.org" <public-audio@w3.org>
Message-Id: <10A8BFB4-8B91-4D0B-82FE-B3726A04DCC3@noteflight.com>
To: rbj@audioimagination.com
As useful as note analysis will be, my opinion is that it doesn't belong in the Web Audio API. It very much seems like something that belongs at the application level as there can be many implementations with different pros and cons and different degrees of user control over the process.

…Joe

> Chris, does this Java script code for note analysis exist somewhere?  i don't know how to write Java or Java script, but what i have seen of Java looks a lot like C at the low level.  if there is a place for this analysis code, i can do this in C and let someone else wrap it up in Java.  it requires pitch tracking, interpolation for the wavetable samples, and phase alignment of adjacent wavetables.  the initial dumb version could have a wavetable for every millisecond or maybe every 2 ms.  and, with a quick FFT on it, each extracted wavetable would have a line spectrum associated with it, in case someone wants to knock off some harmonics (as well as for wavetable culling)
> 
>  
> then we can discuss different ideas behind culling redundant wavetables.  there are some issues there, particularly when interpolating along other dimensions. culling should happen only when the array of wavetables in *all* dimensions are being looked at.  and adjacent wavetables should be phase aligned in all dimensions, not just the slowtime dimension.  that spinning of wavetables (to align them) should happen before culling.  to within reasonable limits, there is not a time constraint on this analysis and wavetable extraction, because it is not real time.  but you don't want to have to take a long coffee break during the analysis either.
> 
>  
> L8r,
> 
>  
> r b-j
> 


Received on Saturday, 11 May 2013 17:38:43 UTC

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