unique IDs etc Re: [linux-audio-dev] Ladspa Gui's (Is ladspa actually la-dsp-a?)

[Mike Rawes]

 --- Steve Harris <S.W.Harris at ecs.soton.ac.uk> wrote: > On Wed, Jun 09, 2004 at
12:16:14 +0100, Chris Cannam wrote:
> > On Wednesday 09 Jun 2004 11:46 am, Steve Harris wrote:
> > > The UID is not globally unique
> > 
> > Well, I would prefer that it wasn't, but unfortunately that does 
> > contradict what ladspa.h specifies and what real hosts expect.
> 
> Nothing in ladspa.h says that UIDs are globally unique - just the .so +
> label combination is guaranteed to be (system) unique.
> 
> > (jack-rack and Rosegarden at least currently use the unique ID to 
> > index plugins and will reject plugins with duplicate IDs.)
> 
> Yep, and I think thier not alone. I only realised that UIDs were not
> globally unique recently myself. Its kinda obvious when you think about
> gnerated plugins, but its very confusing.

/* This numeric identifier indicates the plugin type
     uniquely. Plugin programmers may reserve ranges of IDs from a
     central body to avoid clashes. Hosts may assume that IDs are
     below 0x1000000. */
  unsigned long UniqueID;

 /* This identifier can be used as a unique, case-sensitive
     identifier for the plugin type within the plugin file. Plugin
     types should be identified by file and label rather than by index
     or plugin name, which may be changed in new plugin
     versions. Labels must not contain white-space characters. */
  const char * Label;

leaves host authors with a choice - use UniqueID or filename+label to index
plugins. unsigned longs are easier to manipulate than char *'s, so it's likely
that using the UniqueID has been preferred.

and..

http://www.ladspa.org/ladspa_sdk/unique_ids.html

Not that I'm advocating the continuation of this scheme for reasons already
discussed, but I believe this may be the reason for the confusion!

Hopefully this can be fixed with LADSPA v2...

- 
Myk




	
	
		
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