[linux-audio-dev] LADSPA_Descriptor.ImplementationData usage?

Dave Robillard drobilla at connect.carleton.ca
Tue Apr 25 22:36:37 UTC 2006


On Tue, 2006-04-25 at 23:11 +0100, Steve Harris wrote:
> On Tue, Apr 25, 2006 at 06:01:18PM -0400, Dave Robillard wrote:
> > On Tue, 2006-04-25 at 22:47 +0100, Steve Harris wrote:
> > > I'm in a cruft killing mood.
> > > 
> > > Has anyone ever used ImplementationData? I know I haven't, and I goggled
> > > for it, but all I found was the ladspa.h file, which has a comment to the
> > > affect of: we're not sure why you'd need this, but, just incase here's a
> > > void *.
> > > 
> > > If anoyone has used it, or has a potential use for it, it should stay, but
> > > otherwise it should go IMHO.
> > 
> > I was just thinking this while going through the header (cleaned it up a
> > bit).  I don't even really understand what it's purpose is to be honest,
> > never have.
> > 
> > What does it allow that would not be possible if it weren't there?
> 
> Well, it somewhere to stash "class" level information, but I just use
> statics (easier) and/or shm (harder, but cross host) for that.
> 
> It would be a bit tricky to use as you'd have to be really sure that the
> host was only going to request one descriptor, otherwise you'd have
> multiple copies of your "class" data, which could be either wasteful or
> dangerous.
Ah.  It makes sense I suppose, but class data can be static or just put
in the LADSPA_Handle anyway.

I say if it /can/ go without loss of functionality, it should go, so
let's check...

I just grepped my plugins source directory, which I'm relatively certain
contains every LADSPA plugin ever released (and some that weren't).
Other than some (unused) boilerplate in CMT's C++ wrappper, and setting
it to NULL, it's not used once.

-DR-





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