Plugins

After bundles are loaded, all discovered plugins can be accessed via lilv_world_get_all_plugins():

LilvPlugins* plugins = lilv_world_get_all_plugins(world);

LilvPlugins is a collection of plugins that can be accessed by index or plugin URI. The convenicne macro LILV_FOREACH is provided to make iterating over collections simple. For example, to print the URI of every plugin:

LILV_FOREACH (plugins, i, list) {
  const LilvPlugin* p = lilv_plugins_get(list, i);
    printf("%s\n", lilv_node_as_uri(lilv_plugin_get_uri(p)));
  }
}

More typically, you want to load a specific plugin, which can be done with lilv_plugins_get_by_uri():

LilvNode* plugin_uri = lilv_new_uri(world, "http://example.org/Osc");

const LilvPlugin* plugin = lilv_plugins_get_by_uri(list, plugin_uri);

LilvPlugin has various accessors that can be used to get information about the plugin. See the API reference for details.

Instances

LilvPlugin only represents the data of the plugin, it does not load or access the actual plugin code. To do that, you must instantiate a plugin to create LilvInstance:

LilvInstance* instance = lilv_plugin_instantiate(plugin, 48000.0, NULL);

Connecting Ports

Before running a plugin instance, its ports must be connected to some data. This is done with lilv_instance_connect_port(). Assuming the plugins has two control input ports and one audio output port, in that order:

float control_in_1 = 0.0f;
float control_in_2 = 0.0f;

float audio_out[128];

lilv_instance_connect_port(instance, 0, &control_in_1);
lilv_instance_connect_port(instance, 1, &control_in_2);
lilv_instance_connect_port(instance, 2, &audio_out);

Processing Data

Once the ports are connected, the instance can be activated and run:

lilv_instance_activate(instance);

lilv_instance_run(instance, 128);
// Copy buffers around and probably run several times here...

lilv_instance_deactivate(instance);

Once you are done with an instance, it can be destroyed with lilv_instance_free():

lilv_instance_free(instance);