[LAD] How to develop guis for LV2?

Gabriel M. Beddingfield gabriel at teuton.org
Sun Nov 8 17:49:59 UTC 2009

On Sun, 8 Nov 2009, David Robillard wrote:

>>    + The synths will have several MIDI input ports (for note data)
>>      and several audio output ports.
> Several?  Why?

Several as in "a non-negative integer."  I.e. the host should be prepared 
for a synth that has 1, 2, 3, 4, or even 0 ports.

>>    + All configuration will be done with the events extension.
> Nothing more powerful than MIDI even exists for this yet.  Nothing to do
> with synths.

:-(  Good to know, though.

>>    + Freely use extensions A, B, and C.  If you use any extra
>>      LV2 extensions, try to make them optional.  Otherwise,
>>      please simply call yourself an "LV2 Plugin," because you
>>      won't work with every LV2 Synth Host.
> Extensions that are not necessary to function at all should be optional
> anyway, in all cases.

But if you know up-front which things to make optional... you can adjust 
your implementation.

>> Would somthing like this be *so* bad?
> What benefit does it have?  What problem does it solve?  How is it even

So that I can write a synth plugin and be reasonably assured it will work 
with "everyone's" LV2 synth host.  So that I can write an LV2 host and be 
reasonable assured that it work with "everyone's" LV2 synth plugin.

> any different from what might be the equivalent for an "effect" plugin?

Because Synths are usually more complicated than an effect, and less 
well-defined conceptually.  There's presets, samples, MIDI 
implementations, sound libraries, routings, effects in the sampler, 
variable number of ports, various ways to pass data, etc.

> If you want to start such a thing, it's a wiki for a reason ;)  It's
> much easier to revise there than on the list.

...but much harder to *discuss*. ;)


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