Re: Questions about LV2

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 05/14/2013 12:26 PM, Julien Claassen wrote:
Hello Florian!
I had another look at the sampler and I can't fathom, how the GUI will communicate any extra info to the plugin. Perhaps via one of the sockets, that I saw with lsof. Unfortunately nothing like an OSC server or a direct UDP port as with LinuxSampler. What sort of a plugin did you write and how did you do your extra communications?
  Kind regards
        Julien


Well, I'm no expert on LV2 and especially not the patch extension. But from my limited knowledge the message comes into the plugin the same way midi messages come into it (via a "notification" port?). I ripped the code for my plugin straight from the example sampler plugin from the LV2 distribution. So since it uses a gtk gui to offer the user a way to select a patch file, that's what my plugin does. These are the involved extensions afact:

http://lv2plug.in/ns/ext/patch/patch.html
http://lv2plug.in/ns/ext/state/

Only because you explicitly ask I will elaborate a little bit on my plugin ladspa.m.lv2 (interest was pretty limited, so I actually kind of accepted that it's a personal project interesting only to me ;D). It is a simple little modular synthesis plugin which can run synthesis graphs made up of LADSPA plugins. These synthesis graph definitions are in the form of little files describing the graph. This is the protobuf definition for the files:

https://github.com/fps/ladspa.m.proto/blob/master/ladspam.proto

You can use the generated python bindings to define instruments. This is an example python program that builds up the instrument definition for a simple 5-voice polyphonic instrument that has a sawtooth oscillator per voice and modulation wheel controlled autopanning per voice (where each voice uses a different panning rate):

https://github.com/fps/ladspa.m.proto/blob/master/examples.py/simple_sawtooth_autopanned.instrument.py

The plugin and the involved libraries/tools are still work in progress. But since not a single other part of this chain depends on any graphical toolkit and this is quite accessible it is a pity that the patch selection part to actually make use of an instrument in an LV2 host has this accessibility issue of requiring a custom GUI. And I would love for that to change..

https://github.com/fps/ladspa.m.lv2


Regards,
Flo

--
Florian Paul Schmidt
http://fps.io

_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@xxxxxxxxxxxxxxxxxxxx
http://lists.linuxaudio.org/listinfo/linux-audio-user




[Index of Archives]     [Linux Sound]     [ALSA Users]     [Pulse Audio]     [ALSA Devel]     [Sox Users]     [Linux Media]     [Kernel]     [Photo Sharing]     [Gimp]     [Yosemite News]     [Linux Media]

  Powered by Linux