>TIIR and resampling might both be JOS, but otherwise they're not the same thing. resampling is Julius and Gossett and TIIR is Julius and Wang.
Oh man. It was a long time ago that I looked on TIIR and I have been more used to JOS resampling in the last years. I basically confused the idea of TIIR with the windowed (truncated in mind) band limited impulse. 8-O Sorry! >>if memory is no problem, you can have a whole bunch of windowed sincs stored in a table with different fractional delays ready to rock-n-roll. if the window is good (like a Kaiser) and the length is long enough (i think 16 >>samples is pretty good), i don't think there is a practical aliasing issue at all. a grain that is a windowed sinc need not have *any* practical aliasing issues at all. and if you have enough windowed sincs at various fractional delays, >>you can construct a BLIT of any fundamental frequency. >>because of what i know about resampling (for sample rate conversion and for fractional delay filters), if the windowed sinc was 32 samples long and you had a version of it at 512 different equally-spaced fractional delays and >>you linearly interpolated between two adjacent windowed sincs, any aliasing issues are down 120 dB. i don't worry about -120 dB in a music synthesis alg. i still think that a BLI that is 16 samples long and at, maybe, 64 different >>fractional delays, will be more than good enough using linear interpolation. That is BLIT-SWS: windowed sinc linearly interpolated. So we are clear on this and agree on everything. Just know that at the beginning I was on the quest of perfect algo for zero-alias, so accepting it even (if reduced) to me was a turn off (but I am a perfectionist so apologies :D ). >> If you want no aliasing in BLIT you must use DSF or sincM who suffer >> of what I already explained. sorry, i'm clueless about the alfabet soup. i know "BLIT" and i know "sinc". DSF is the Discrete Sumation Formulae (originally by Moorer I guess) and sincM(x) = sin(pi x)/M sin(pi x/M): both provide a periodic pulse train bandlimited (NO ALIAS). >> Using non-leaky integrators (ideal) leads to what you say (basically >> roundoff errors which are never forgot) and AFAIK no one uses them. >noise shaping deals with roundoff errors. Yes but...I dont follow you here (I intended no one uses ideal integrators in BLIT). Ideal integration to me means the simple running sum as a trivial example: so a running sum of past values has roundoff errors that at some point will blow the integrator up. More generally DC gain is infinite in integrators so any roundoff resulting in DC can be amplified infinitely. That's why everybody uses leaky ones, and the TRI/SAW/SQR waveforms are not "textbook-like". >take care of your kids. i'm doing similarly (but my baby is now 14 years old). Thanks, same to you. If you are interested in the subject I suggest to read the Stilson paper about BLIT (if you haven't yet). I have basically explained in this thread my experience in implementing all his techniques. https://ccrma.stanford.edu/~stilti/papers/blit.pdf Marco -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
