[PD] OT: Windowing

[matthew jones]

Hi,
quick OT question for any of the granular synthesis brains out there...
I want to reconstruct a signal from multiple overlapped segments.  To use an
overlapp-add method that perfectly reconstructs the original waveform I
would need to window the segments... now thats fine as long as the overlap
amount is less than 50 percent.  I can use a Hanning window on the
overlapping parts and sum them..... Hanning windows satisfy the sum to unity
criterion.  however, when the overlap is more than 50%, the half-Hanning
windows applied to the start and end of the segments windows begin to
overlap.... see this link:
http://www.loopit.org/images/overlap.jpg

Now multiplying the overlapped half-Hanning windows together creates a new
window function for the segments that suddenly does not satisfy the
'sum-to-unity' criterion....
The question is (if anybody can is at all interested):- WHAT window function
should be used given ANY arbitrary overlap amount???

Any answers would really help me, though I'd be surprised if this gets a
response.... ;)
sorry 2 b so off topic, though for me it's pd related anyway(!). cheers

matt

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