On Wednesday 18 December 2002 11.51, Steve Harris wrote: > On Wed, Dec 18, 2002 at 11:22:44 +0100, David Olofson wrote: > > It's not very hard to do for basic stuff, and it means many > > plugins won't need any internal filtering at all. > > Unlikly. Most plugins will only render the control values ever 32 > samples (say) and then will just use linear sections between those. > > I think providing all that specification is a mistake, its quite > complex and will not be usefull most of the time. > > > Many effects will make this audible, and thus, will need to > > implement filtering internally anyway. Splines can probably > > eliminate this in most cases. > > > > We should probably try it though. Anyone around here has real > > experience with this? > > Splines have some unfortunate side effects, like excursions, which > make them only suitable for a small number of cases. Also the > calcuation cost means they have to be used sparingly. > > The place the're most useful is where you have high bandwidth, low > rate of change values, eg. in internal ringbuffer pointers. You > wouldn't want to use them on external controls very often.
Right. I've mentioned that you're really meant to deal only with the current block, and thus, we're *not* talking about low rates of changes. (BTW, AudioUnits also does it this way, if I understand it correctly. You have to keep telling the receiving control about the ramp for each block.) > Also, remember that most of the time the controls are going to come > (ultimatly) from the user moving a slider around (etiher real or > GUI) its not easy to generate good splines from that data. Ramps > are much more practical, and more convienient for the DSP > programmer. All good points. It seems to me that we should do like everyone else: Linear ramps only. Dead simple (well, almost), well defined and *very* much better than no ramps at all. //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 ---