On Wednesday 05 February 2003 14.00, Sami P Perttu wrote: > On Wed, 5 Feb 2003, David Olofson wrote: > > Anyway, the reason for not using Hz or similar in the API is that > > such units are harder to deal with, pretty much no matter what > > you want to do. The only exception is when you actually want to > > have some periodic action driven by it, ie sound. Thus, rather > > than using Hz in the API and having event processors and whatnot > > convert back and forth, we use linear pitch (1.0/octave) > > throughout, and leave it to the final stage; the synth, to > > convert it into whatever drives it's > > Okay, that is some kind of answer. The needs of the event > processors outweigh the needs of the audio processors.
Not quite. It's only a matter of *where* to perform the conversion. It can never be avoided entirely. (Unless we assume that users will want to paint events in piano rolls with Hz on the vertical scale, that is. ;-) > > oscillators. Which, mind you, is not necessarily Hz or > > samples/period! It may well be coefficients for a resonant filter > > you need. > > I guess you'd still convert them to linear frequency on the way. Not if you're using an optimized approximation. That generally boils down to a plain polynomial or similar function, translating whatever you have directly into whatever you want. > > As to actually doing the conversion, I suppose we could throw > > some inline implementations into the plugin SDK. > > Yes, a control iterator would be nice: something that takes a pitch > ramp event as input and then produces Hz values each sample as > output. Yeah, we can have all sorts of stuff like that. It's not really part of the API, so it won't be as hard to "get stuff in" - although it's obviously still a good idea to keep things nice and clean, and avoid obvious redundancies. After all, an SDK isn't of much help if it takes longer to find and/or understand what you need than it would take to implement it on your own. //David Olofson - Programmer, Composer, Open Source Advocate .- The Return of Audiality! --------------------------------. | Free/Open Source Audio Engine for use in Games or Studio. | | RT and off-line synth. Scripting. Sample accurate timing. | `---------------------------> http://olofson.net/audiality -' --- http://olofson.net --- http://www.reologica.se ---
