[LAA] [ANN] LV2 Revision 3

Dave Robillard dave at drobilla.net
Thu Nov 13 19:52:14 EST 2008

LV2 is a standard for plugins and matching host applications, mainly
targeted at audio processing and generation.  LV2 is a simple but
extensible successor of LADSPA, intended to address the limitations of
LADSPA which many applications have outgrown.

This revision changes the data portion of the specification only (i.e.
lv2.h is unchanged).


This revision makes a simple but important clarification, relevant to
both host and plugin and authors:

A serialisation (i.e. save files, patch files, preset files, network
protocols, anything not associated with a specific plugin binary) which
refers to an LV2 port MUST do so using the port symbol and NOT the port
index.  Of course, at runtime the index may still be used, as in LADSPA.
This is not a binary change.

See lv2.ttl for details and rationale, but in short this allows much
more elbow room for plugin authors to improve their plugins over time
without changing the URI, and opens the door for fully dynamic ports on
plugins without backwards compatibility issues, among other things.

Some developers have complained about the strict URI/versioning rules,
these issues are resolved in this revision without weakening
compatibility guarantees.  Plugin authors: no more worrying about port
indices!  Further discussion is best done on the LV2 development list,
see <http://lv2plug.in> for more information.

Upgrading and ensuring correctness is STRONGLY encouraged for host
authors, so plugin authors can apply this new freedom in practice.

Specification download: <http://lv2plug.in/spec/lv2core-3.0.tar.bz2>


- The LV2 Team

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