[linux-audio-dev] PTAF link and comments

[Sami P Perttu]

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.

> 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.

> 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.

--
Sami Perttu                       "Flower chase the sunshine"
Sami.Perttu at hiit.fi               http://www.cs.helsinki.fi/u/perttu