[LAD] Portable user interfaces for LV2 plugins

Stefano D'Angelo zanga.mail at gmail.com
Fri Mar 4 14:40:51 UTC 2011

2011/3/4 Olivier Guilyardi <list at samalyse.com>:
> On 03/04/2011 01:53 PM, Stefano D'Angelo wrote:
>> Hence, in this case, I think we should exploit the
>> extensibility/decentralization of LV2: those who, like me, care about
>> "control rate" visualization hints may want to help on web UIs, for
>> example, the others might do the same with native GL.
>> The only thing that we all need to ensure is that things work well
>> together, whatever the host/plugin author choice is, also trying to
>> make the whole thing as painless as it can be for everybody.
>> Side note: this is yet another case where we could proceed to some
>> structured effort coordination at this point, but my feeling is that
>> this won't happen and the discussion will lead nowhere in the end.
> There is one thing which stays on my mind.
> I am familiar with developing JACK clients, not plugins. However, there has been
> quite a few discussions in the past where JACK was advocated as a way to create
> modules, DSP units dedicated to a specific task. In other terms: some kind of
> plugins.
> And what is absolutely nice about this is how it is non-intrusive. When working
> on a JACK client, there are only audio input and output ports, a thin transport
> layer, done. From these primitives, upon this bare but solid ground, a developer
> creativity enjoys a lot of freedom.
> However, there's been this critical and long-lasting session handling problem.
> Fortunately, this problem doesn't occur for LADSPA and LV2 plugins, since saving
> and restoring state is performed by the host.
> But, with this UI/engine separation, whenever a developer comes out with an
> innovative idea that he really likes, he's very likely to hit a wall because of
> a specific LV2 technical constraint. And at the same time it takes an incredible
> (if only possible) coordination effort to maintain LV2 to fulfill and
> *anticipate* all needs.
> But LV2 is extensible. So what I think is that in addition to the extensions
> which imply UI/engine separation (and I understand that it's important in many
> cases), there should be a DoWhatTheFuckYouWantInYourPlugin extension ;)
> With such plugins, restoring/saving state would rely on passing a blob in
> addition to restoring/saving the control ports values. There would be no such
> thing as UI/engine separation. The plugin would be self contained. And hopefully
> it would integrate nicely with other extensions such as midi.

Actually control ports do not define the state alone, the state also
includes plugin-specific data (the stuff the LV2_Handle thing should
point to) - and that is generally a binary blob anyway (unless you do
some other kind of storing/restoring, like with key/value pairs,

> I think that this extension, since it would only imply simple but powerful
> primitives, would give a lot of freedom to developers who want that, and at the
> same time be rather easy to maintain.

Why do you hate yourself so much?

/me buys popcorn and waits for Dave to bash you hard. :-)

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