[linux-audio-dev] Plugin APIs (again)

[David Olofson]

On Monday 09 December 2002 16.57, Steve Harris wrote:
> On Mon, Dec 09, 2002 at 03:49:55PM +0100, David Olofson wrote:
> > > Converting between continuous control and event control is not
> > > reliable, and kinda removes the point of cont. control.
> >
> > Yes, but without converters, you can't do things like applying
> > audio effects on controls...
>
> Right, so I think its better to just ignore it. Where people
> want/need it they will just use audio ports (like in LADSPA).

So, what do you do if you don't *have* the source signal you want in 
audio format? Hack the plugin? (Yeah, ordinary users will love 
that...)


> > Well, yeah - and if you can run hundreds of *those*, it probably
> > doesn't matter that every single synth voice spends more CPU time
> > processing control data than audio. :-)
>
> Well, when people start writing audio rate DSP software that isn't
> full of hacky optimisation and aproximations the audio rate stuff
> will be much slower than the control rate stuff ;)

So, *that's* how desktop applications got as insanely slow as they 
are these days... :-)

"If I don't need to optimize this, I don't need to optimize that..."


> > Yes - but I'd rather not wait ten years before I can actually
> > *use* my software! :-)
>
> I use audio rate control software now, it just limits the amount of
> synthesis you can do on a modern machine from ludicrous to just
> excessive
> :)

Well, that sounds ok. :-)


> > In fact, I've already waited *more* than ten years already for
> > PCs to become at all usable for serious audio synthesis and
> > recording. Now they are, but since I didn't have Linux/lowlatency
> > some years ago, I never got around to write any hopelessly
> > inefficient software that would have been just fine today. ;-)
>
> Really? I wrote some offline sysntesis software years ago (amiga
> and sun4) that would run realtime now. Though theres no point
> porting it, it didn't sound very good :) Thats more down to my lack
> of ability than anything else. I bet there are people with old
> csound scores they can now run realtime.

Well, there's a practical problem with off-line stuff as well; 
tweaking until you get the perfect sound takes ages... *hehe*

BTW, I did write some Amiga software back then - but that actually 
ran in real time, and obviously couldn't sound all that great. (And 
though the 25 MHz A3000 helped a lot, it was still very far from even 
the lowest end synths. Either voices or quality; not both.)


> > > There are some hardware synths in existence today that use
> > > cont. control and blockless processing. The improvement in
> > > sound quality is noticable.
> >
> > Do they use that for *everything* (like all parameters, switches
> > etc), or just where it actually matters?
>
> The one I know most about has some controls that run at a reduced
> rate (1/4). But everything is a stream, no events and no blocks.

Well, we'll need a *few* more registers to do this on workstations, I 
think...! :-)

Until we can do away with blocks, we probably can't do away with 
events either. Those sort of belong in the same order of magnitude of 
work vs overhead.


//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 -'
.- M A I A -------------------------------------------------.
|    The Multimedia Application Integration Architecture    |
`----------------------------> http://www.linuxdj.com/maia -'
   --- http://olofson.net --- http://www.reologica.se ---