Features for mapping URIs to and from integers.
This extension defines a simple mechanism for plugins to map URIs to and from integers, usually for performance reasons (e.g. processing events typed by URIs in real time). Typically, plugins map URIs to integers for things they "understand" at instantiation time, and store those values for use in the audio thread without doing any string comparison. This allows for the extensibility of RDF but with the performance of integers. This extension is intended as an improved and simpler replacement for the uri-map extension, since the map context parameter has been found problematic.
A feature which is used to map URIs to integers. To support this feature, the host must pass an LV2_Feature to LV2_Descriptor::instantiate() with URI http://lv2plug.in/ns/ext/urid#map and data pointed to an instance of LV2_URID_Map.
A feature which is used to unmap URIs previously mapped to integers by urid:map. To support this feature, the host must pass an LV2_Feature to LV2_Descriptor::instantiate() with URI http://lv2plug.in/ns/ext/urid#unmap and data pointed to an instance of LV2_URID_Unmap.