[linux-audio-dev] LADSPA Hosting

[Steve Harris]

On Wed, Apr 16, 2003 at 04:56:20 -0400, Nick Tsocanos wrote:
> On Wed, 2003-04-16 at 16:03, ian wrote:
> > the simplest way to determine if an algorithm is likely to be an effect or
> > not is just to count the number of audio input and audio output ports.
> Yep, that's how I did it. But, surprise! Some weird ones use AUDIO
> signals for control data (oscillators use it for amplitude). So, to hack
> around this, I check to see if the audio port is bounded by below or
> above.

There is a proposed hint to cover this, it would indicate that an audio
rate input was actualy intended for control type signals.
 
> Oh I don't want to limit them at all, but some plugins refuse to work at
> all, and mangle the effect chain! Those aren't cool, they just don't
> work properly in my app. Of course, it might be a bug somewhere in my
> driver.. I only just made this today... and I am still working on it
> pretty heavy right now.

There are some *cough* known bugs in many LADSPA plugins.
 
> Anyone use Dj Flanger? Is there something you have to do to use this
> plugin? When I use it it makes terrible noises.

That one works AFAIK. Theres nothing special about it.
 
> I plan on doing alot of LADSPA plugins. Why? It's so simple API to use.
> It has only taken me an afternoon to build a host app and even build my
> GUIs at run time for it with FLTK. It's great! And alot of those F/X
> sound WILD!

Cool :) Incase you haven't seen it I recommend by XML LADSPA build system, 
it makes writing plugins very easy, by taking away all the tedious struct
mangling. I had a half written tutorial, but I'm not sure what I did with
it.

- Steve