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 Kyma Forum
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 Bristow-Johnson Window
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| Author | Topic: Bristow-Johnson Window |
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David McClain Member |
posted 04 May 2001 10:57
 
...anyone know the definition of this windowing function? Thanks, - DM IP: Logged |
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David McClain Member |
posted 04 May 2001 11:48
I spent a few hours searching and finally found something in a note posted by Robert Bristow-Johnson, using a Googol Search. He refers to a "flattened Hann" window given as He claims (I haven't checked yet, but I'll believe him) that this window has continuous first and second derivatives. Is this what SSC is calling the Bristow-Johnson window? [Mathematica shows it to have continuous derivatives through 3rd order!! -- In fact for all odd higher order derivatives...] - DM [This message has been edited by David McClain (edited 04 May 2001).] IP: Logged |
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David McClain Member |
posted 04 May 2001 12:38
Oh HO!!! More important than all the continuous derivatives, for us anyway, is the fact that the Hann, Bristow-Johnson, and Bartlett (triangular), windows all are complementary in the sense that the sum of any value plus the value a half-period away is unity!!! Ooohoo!! This is why they make such good cross-fading windows for output from the block FFT processing algorithms. And this is why I don't hear any kind of low-level hum AM carrier on the outputs of these block FFT Sounds in Kyma. Nice job SSC!!! - DM IP: Logged |
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SSC Administrator |
posted 04 May 2001 13:08
We found it in a paper by Robert Bristow-Johnson: R. Bristow-Johnson, "A Detailed Analysis of a Time-Domain Formant-Corrected Pitch Shifting Algorithm", J. Audio Eng. Soc., vol. 43, no. 5, pp. 340-352 (1995 May). He was a little embarassed that we named the window after him in Kyma, citing some earlier uses of that same window function. IP: Logged |
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David McClain Member |
posted 04 May 2001 13:17
Yes! I saw the references to that paper in several places too. But unfortunately it is not yet available on-line. But my compliment to you stands! You chose very cleverly in your selection of windowing functions. You really should say more about this sort of thing in your manuals! - DM [This message has been edited by David McClain (edited 04 May 2001).] IP: Logged |
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