[linux-audio-dev] Re: [jmax] Running a patch as a LADSPA plugin

[torbenh at gmx.de]

On Tue, Mar 18, 2003 at 12:04:46PM +0100, Francois Dechelle wrote:
> On Tue, 2003-03-18 at 10:36, Steve Harris wrote:
> 
> > Thats OK as a quick fix, but it doesn't solve the broader problem, if you
> > save state from a host using jMax LADSPA plugins then it wont necceserily
> > be the same set when you reload.
> > 
> > I think LADSPA needs self assigned ID's, if the UID space were bigger we
> > could just reseve the top bit for self assigned stuff and hash unique
> > strings to fill it, but as its only 32bits thats not enough space.
> > 
> > > Apart from this solution, I don't see how to do it.
> > 
> > Agreed, without a change to LADSPA I dont think its possible.
> > 
> > One solution could be to use a reserved ID range to flag that the ID isn't
> > globally unique, but the label string (not name) is, so hosts should save
> > state aginst the label not the ID. It has very dodgy semantics though.
> > 
> > A better solution would be to expand the ID space to 64bits, and reserve
> > the top bit's worth, which is plenty, but will break binary compatibility
> > of course.
> 
> In any case, hosts that save the ID cannot restore the plugin settings
> correctly, if the ID is assigned dynamically. 
> 
> Currently, in the jMax LADSPA plugin, the label is the basename of the
> patch file. This is clearly unique.
> 
> What is the usual strategy for LADSPA hosts that save their state? Do
> they store only the ID or also the label? 

galan saves against the label.
I wanted to change this to the UID after thinking the label was not
unique. But if i get this right the label is unique. And then i will
leave it like it is.

> 
> Also, does the UID really need to be unique? If not, one UID for jMax
> could be enough. Different plugins will differ by their label.
> 
> 
> >  
> > > Another question: is there a plan to get plugin port values that are not
> > > floats? More precisely, I am thinking of transforming a patch that does
> > > granular synthesis into a plugin. But this patch needs a sound file
> > > name. How can I pass it to the LADSPA plugin?
> > 
> > You can't. I think this is thought to be outside the remit of LADSPA.
> 
> Too bad. Is there any trick to twist LADSPA plugins for that? 

you could stream it into an audio input... but this is really ugly...
i would write a string event to audio converter if you used this
approach.


-- 
torben Hohn
http://galan.sourceforge.net -- The graphical Audio language