[LAD] Portable user interfaces for LV2 plugins

David Robillard d at drobilla.net
Thu Mar 3 00:04:01 UTC 2011

On Wed, 2011-03-02 at 23:36 +0100, Stefano D'Angelo wrote:
> 2011/3/2 Paul Davis <paul at linuxaudiosystems.com>:
> > AU, which is the only other plugin API to explicitly support
> > plugin<->GUI separation (even across processes) works in exactly the
> > same way as LV2. there are many AU plugins which do precisely what you
> > describe, yet still use a host-mediated parameter accessor API to both
> > control and represent current plugin state. this conceptual issue has
> > been thrashed out many times on the coreaudio mailing list as far back
> > as 1994, and nobody ever convinced the coreaudio guys (who are a smart
> > bunch of guys) that they had done it wrong.
> Since I'm not just complaining or posing hypotetical questions, but
> want the understand the issue at its deepest, I want to ask you to
> please better point out what is exactly this host-mediate parameter
> accessor API (a link to docs is more than enough).

The host provides a LV2UI_Write_Function for UIs to send to plugins (via
a port):


The host calls port_event on the LV2UI_Descriptor to notify the UI about
activity at a port:


The relevant header is:



P.S. Sure would be nice of Doxygen could do human readable URIs for this
sort of thing...

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