On Dec 11, 2007 7:35 AM, Hector Centeno wrote: > I've been looking for the most efficient way of "bandpass" filtering > bins in a fsig for a realtime instrument. What I want to do is to be > able to split an fsig into different fsigs containing diferent bin > sections (for independent processing). I guess I could use the pvsftr > and pvsftw opcodes together with the vectorial opcodes to alter the > table, but I was wondering if I'm missing any other way of doing it > more CPU efficient without having to rewrite tables (I want to be able > to change the ranges realtime). Also I thought about using pvstencil I thought of pvsmaska, but that uses ftables too. There is pvsfilter; I suppose you could generate a signal with pure sines of the right frequencies, pvsanal it, and pvsfilter the two fsigs. I would guess pvsmaska is more efficient. I'm afraid I still don't completely understand Csound's frequency-amplitude pairs. I read some of the documentation offered when I asked about it, but from what I could tell it was still referring to equally spaced bins, where pvsvoc implies that the frequencies of one fsig can differ from those of another fsig of the same size. Point being that, if you don't know what frequencies the bins of your signal will have, how do you know what frequencies to use for sines to analyze to get the desired filter? And my suspicion being that the bins have fixed frequency values, and "amp-freq" pair refers to "freq" being the same for all fsigs of the same size... Anyway I would personally use pvsmaska; I don't know how a k-rate specification would even work, if it has to specify 512 or however many values per control period. pvsbufread has upper and lower limits of which frequencies to include... > On the request side: It could be nice to have an opcode for doing > this, one that simply takes a fsig and two k-rate parameters for the > lowest and highest bin and outputs another fsig containing only those > bins with the rest zeroed. Sounds like pvsbufread. I haven't played with it to know how much delay is necessary, but maybe I will today... -Chuckk -- http://www.badmuthahubbard.com