ardour/libs/ardour/lv2_plugin.cc

/*
    Copyright (C) 2008-2012 Paul Davis
    Author: David Robillard

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <cctype>
#include <string>
#include <vector>
#include <limits>

#include <cmath>
#include <cstdlib>
#include <cstring>

#include "pbd/gstdio_compat.h"
#include <glib/gprintf.h>
#include <glibmm.h>

#include <boost/utility.hpp>

#include "pbd/file_utils.h"
#include "pbd/stl_delete.h"
#include "pbd/compose.h"
#include "pbd/error.h"
#include "pbd/locale_guard.h"
#include "pbd/replace_all.h"
#include "pbd/xml++.h"

#include "libardour-config.h"

#include "ardour/audio_buffer.h"
#include "ardour/audioengine.h"
#include "ardour/debug.h"
#include "ardour/lv2_plugin.h"
#include "ardour/midi_patch_manager.h"
#include "ardour/session.h"
#include "ardour/tempo.h"
#include "ardour/types.h"
#include "ardour/utils.h"
#include "ardour/worker.h"
#include "ardour/search_paths.h"

#include "pbd/i18n.h"
#include <locale.h>

#include <lilv/lilv.h>

#include "lv2/lv2plug.in/ns/ext/atom/atom.h"
#include "lv2/lv2plug.in/ns/ext/atom/forge.h"
#include "lv2/lv2plug.in/ns/ext/log/log.h"
#include "lv2/lv2plug.in/ns/ext/midi/midi.h"
#include "lv2/lv2plug.in/ns/ext/port-props/port-props.h"
#include "lv2/lv2plug.in/ns/ext/presets/presets.h"
#include "lv2/lv2plug.in/ns/ext/state/state.h"
#include "lv2/lv2plug.in/ns/ext/time/time.h"
#include "lv2/lv2plug.in/ns/ext/worker/worker.h"
#include "lv2/lv2plug.in/ns/ext/resize-port/resize-port.h"
#include "lv2/lv2plug.in/ns/extensions/ui/ui.h"
#include "lv2/lv2plug.in/ns/extensions/units/units.h"
#include "lv2/lv2plug.in/ns/ext/patch/patch.h"
#include "lv2/lv2plug.in/ns/ext/port-groups/port-groups.h"
#ifdef HAVE_LV2_1_2_0
#include "lv2/lv2plug.in/ns/ext/buf-size/buf-size.h"
#include "lv2/lv2plug.in/ns/ext/options/options.h"
#endif

#include "lv2_evbuf.h"

#ifdef HAVE_SUIL
#include <suil/suil.h>
#endif

// Compatibility for old LV2
#ifndef LV2_ATOM_CONTENTS_CONST
#define LV2_ATOM_CONTENTS_CONST(type, atom) \
	((const void*)((const uint8_t*)(atom) + sizeof(type)))
#endif
#ifndef LV2_ATOM_BODY_CONST
#define LV2_ATOM_BODY_CONST(atom) LV2_ATOM_CONTENTS_CONST(LV2_Atom, atom)
#endif
#ifndef LV2_PATCH__property
#define LV2_PATCH__property LV2_PATCH_PREFIX "property"
#endif
#ifndef LV2_PATCH__value
#define LV2_PATCH__value LV2_PATCH_PREFIX "value"
#endif
#ifndef LV2_PATCH__writable
#define LV2_PATCH__writable LV2_PATCH_PREFIX "writable"
#endif

/** The number of MIDI buffers that will fit in a UI/worker comm buffer.
    This needs to be roughly the number of cycles the UI will get around to
    actually processing the traffic.  Lower values are flakier but save memory.
*/
static const size_t NBUFS = 4;

using namespace std;
using namespace ARDOUR;
using namespace PBD;

bool LV2Plugin::force_state_save = false;

class LV2World : boost::noncopyable {
public:
	LV2World ();
	~LV2World ();

	void load_bundled_plugins(bool verbose=false);

	LilvWorld* world;

	LilvNode* atom_AtomPort;
	LilvNode* atom_Chunk;
	LilvNode* atom_Sequence;
	LilvNode* atom_bufferType;
	LilvNode* atom_eventTransfer;
	LilvNode* atom_supports;
	LilvNode* ev_EventPort;
	LilvNode* ext_logarithmic;
	LilvNode* ext_notOnGUI;
	LilvNode* ext_expensive;
	LilvNode* ext_causesArtifacts;
	LilvNode* ext_notAutomatic;
	LilvNode* ext_rangeSteps;
	LilvNode* groups_group;
	LilvNode* groups_element;
	LilvNode* lv2_AudioPort;
	LilvNode* lv2_ControlPort;
	LilvNode* lv2_InputPort;
	LilvNode* lv2_OutputPort;
	LilvNode* lv2_designation;
	LilvNode* lv2_enumeration;
	LilvNode* lv2_freewheeling;
	LilvNode* lv2_inPlaceBroken;
	LilvNode* lv2_isSideChain;
	LilvNode* lv2_index;
	LilvNode* lv2_integer;
	LilvNode* lv2_default;
	LilvNode* lv2_minimum;
	LilvNode* lv2_maximum;
	LilvNode* lv2_reportsLatency;
	LilvNode* lv2_sampleRate;
	LilvNode* lv2_toggled;
	LilvNode* midi_MidiEvent;
	LilvNode* rdfs_comment;
	LilvNode* rdfs_label;
	LilvNode* rdfs_range;
	LilvNode* rsz_minimumSize;
	LilvNode* time_Position;
	LilvNode* ui_GtkUI;
	LilvNode* ui_external;
	LilvNode* ui_externalkx;
	LilvNode* units_hz;
	LilvNode* units_db;
	LilvNode* units_unit;
	LilvNode* units_render;
	LilvNode* units_midiNote;
	LilvNode* patch_writable;
	LilvNode* patch_Message;
#ifdef HAVE_LV2_1_2_0
	LilvNode* bufz_powerOf2BlockLength;
	LilvNode* bufz_fixedBlockLength;
	LilvNode* bufz_nominalBlockLength;
	LilvNode* bufz_coarseBlockLength;
#endif

#ifdef HAVE_LV2_1_10_0
	LilvNode* atom_int;
	LilvNode* atom_float;
	LilvNode* atom_object; // new in 1.8
	LilvNode* atom_vector;
#endif
#ifdef LV2_EXTENDED
	LilvNode* lv2_noSampleAccurateCtrl;
	LilvNode* auto_can_write_automatation; // lv2:optionalFeature
	LilvNode* auto_automation_control; // atom:supports
	LilvNode* auto_automation_controlled; // lv2:portProperty
	LilvNode* auto_automation_controller; // lv2:portProperty
#endif

private:
	bool _bundle_checked;
};

static LV2World _world;

/* worker extension */

/** Called by the plugin to schedule non-RT work. */
static LV2_Worker_Status
work_schedule(LV2_Worker_Schedule_Handle handle,
              uint32_t                   size,
              const void*                data)
{
	return (((Worker*)handle)->schedule(size, data)
	        ? LV2_WORKER_SUCCESS
	        : LV2_WORKER_ERR_UNKNOWN);
}

/** Called by the plugin to respond to non-RT work. */
static LV2_Worker_Status
work_respond(LV2_Worker_Respond_Handle handle,
             uint32_t                  size,
             const void*               data)
{
	return (((Worker*)handle)->respond(size, data)
	        ? LV2_WORKER_SUCCESS
	        : LV2_WORKER_ERR_UNKNOWN);
}

#ifdef LV2_EXTENDED
/* inline display extension */
static void
queue_draw (LV2_Inline_Display_Handle handle)
{
	LV2Plugin* plugin = (LV2Plugin*)handle;
	plugin->QueueDraw(); /* EMIT SIGNAL */
}

static void
midnam_update (LV2_Midnam_Handle handle)
{
	LV2Plugin* plugin = (LV2Plugin*)handle;
	plugin->UpdateMidnam (); /* EMIT SIGNAL */
}
#endif

/* log extension */

static int
log_vprintf(LV2_Log_Handle /*handle*/,
            LV2_URID       type,
            const char*    fmt,
            va_list        args)
{
	char* str = NULL;
	const int ret = g_vasprintf(&str, fmt, args);
	/* strip trailing whitespace */
	while (strlen (str) > 0 && isspace (str[strlen (str) - 1])) {
		str[strlen (str) - 1] = '\0';
	}
	if (strlen (str) == 0) {
		return 0;
	}

	if (type == URIMap::instance().urids.log_Error) {
		error << str << endmsg;
	} else if (type == URIMap::instance().urids.log_Warning) {
		warning << str << endmsg;
	} else if (type == URIMap::instance().urids.log_Note) {
		info << str << endmsg;
	} else if (type == URIMap::instance().urids.log_Trace) {
		DEBUG_TRACE(DEBUG::LV2, str);
	}
	return ret;
}

static int
log_printf(LV2_Log_Handle handle,
           LV2_URID       type,
           const char*    fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	const int ret = log_vprintf(handle, type, fmt, args);
	va_end(args);
	return ret;
}

struct LV2Plugin::Impl {
	Impl() : plugin(0), ui(0), ui_type(0), name(0), author(0), instance(0)
	       , work_iface(0)
#ifdef HAVE_LV2_1_2_0
	       , opts_iface(0)
#endif
	       , state(0)
	       , block_length(0)
#ifdef HAVE_LV2_1_2_0
	       , options(0)
#endif
#ifdef LV2_EXTENDED
	       , queue_draw(0)
	       , midnam(0)
#endif
	{}

	/** Find the LV2 input port with the given designation.
	 * If found, bufptrs[port_index] will be set to bufptr.
	 */
	const LilvPort* designated_input (const char* uri, void** bufptrs[], void** bufptr);

	const LilvPlugin*            plugin;
	const LilvUI*                ui;
	const LilvNode*              ui_type;
	LilvNode*                    name;
	LilvNode*                    author;
	LilvInstance*                instance;
	const LV2_Worker_Interface*  work_iface;
#ifdef HAVE_LV2_1_2_0
	const LV2_Options_Interface* opts_iface;
#endif
	LilvState*                   state;
	LV2_Atom_Forge               forge;
	LV2_Atom_Forge               ui_forge;
	int32_t                      block_length;
#ifdef HAVE_LV2_1_2_0
	LV2_Options_Option*          options;
#endif
#ifdef LV2_EXTENDED
	LV2_Inline_Display*          queue_draw;
	LV2_Midnam*                  midnam;
#endif
};

LV2Plugin::LV2Plugin (AudioEngine& engine,
                      Session&     session,
                      const void*  c_plugin,
                      framecnt_t   rate)
	: Plugin (engine, session)
	, Workee ()
	, _impl(new Impl())
	, _features(NULL)
	, _worker(NULL)
	, _state_worker(NULL)
	, _insert_id("0")
	, _patch_port_in_index((uint32_t)-1)
	, _patch_port_out_index((uint32_t)-1)
	, _uri_map(URIMap::instance())
	, _no_sample_accurate_ctrl (false)
{
	init(c_plugin, rate);
}

LV2Plugin::LV2Plugin (const LV2Plugin& other)
	: Plugin (other)
	, Workee ()
	, _impl(new Impl())
	, _features(NULL)
	, _worker(NULL)
	, _state_worker(NULL)
	, _insert_id(other._insert_id)
	, _patch_port_in_index((uint32_t)-1)
	, _patch_port_out_index((uint32_t)-1)
	, _uri_map(URIMap::instance())
	, _no_sample_accurate_ctrl (false)
{
	init(other._impl->plugin, other._sample_rate);

	for (uint32_t i = 0; i < parameter_count(); ++i) {
		_control_data[i] = other._shadow_data[i];
		_shadow_data[i]  = other._shadow_data[i];
	}
}

void
LV2Plugin::init(const void* c_plugin, framecnt_t rate)
{
	DEBUG_TRACE(DEBUG::LV2, "init\n");

	_impl->plugin           = (const LilvPlugin*)c_plugin;
	_impl->ui               = NULL;
	_impl->ui_type          = NULL;
	_to_ui                  = NULL;
	_from_ui                = NULL;
	_control_data           = 0;
	_shadow_data            = 0;
	_atom_ev_buffers        = 0;
	_ev_buffers             = 0;
	_bpm_control_port       = 0;
	_freewheel_control_port = 0;
	_latency_control_port   = 0;
	_next_cycle_start       = std::numeric_limits<framepos_t>::max();
	_next_cycle_speed       = 1.0;
	_seq_size               = _engine.raw_buffer_size(DataType::MIDI);
	_state_version          = 0;
	_was_activated          = false;
	_has_state_interface    = false;
	_can_write_automation   = false;
	_max_latency            = 0;
	_current_latency        = 0;
	_impl->block_length     = _session.get_block_size();

	_instance_access_feature.URI = "http://lv2plug.in/ns/ext/instance-access";
	_data_access_feature.URI     = "http://lv2plug.in/ns/ext/data-access";
	_make_path_feature.URI       = LV2_STATE__makePath;
	_log_feature.URI             = LV2_LOG__log;
	_work_schedule_feature.URI   = LV2_WORKER__schedule;
	_work_schedule_feature.data  = NULL;
	_def_state_feature.URI       = LV2_STATE_PREFIX "loadDefaultState";  // Post LV2-1.2.0
	_def_state_feature.data      = NULL;

	const LilvPlugin* plugin = _impl->plugin;

	LilvNode* state_iface_uri = lilv_new_uri(_world.world, LV2_STATE__interface);
	LilvNode* state_uri       = lilv_new_uri(_world.world, LV2_STATE_URI);
	_has_state_interface =
		// What plugins should have (lv2:extensionData state:Interface)
		lilv_plugin_has_extension_data(plugin, state_iface_uri)
		// What some outdated/incorrect ones have
		|| lilv_plugin_has_feature(plugin, state_uri);
	lilv_node_free(state_uri);
	lilv_node_free(state_iface_uri);

	_features    = (LV2_Feature**)calloc(13, sizeof(LV2_Feature*));
	_features[0] = &_instance_access_feature;
	_features[1] = &_data_access_feature;
	_features[2] = &_make_path_feature;
	_features[3] = _uri_map.uri_map_feature();
	_features[4] = _uri_map.urid_map_feature();
	_features[5] = _uri_map.urid_unmap_feature();
	_features[6] = &_log_feature;

	unsigned n_features = 7;
#ifdef HAVE_LV2_1_2_0
	_features[n_features++] = &_def_state_feature;
#endif

	lv2_atom_forge_init(&_impl->forge, _uri_map.urid_map());
	lv2_atom_forge_init(&_impl->ui_forge, _uri_map.urid_map());

#ifdef LV2_EXTENDED
	_impl->queue_draw = (LV2_Inline_Display*)
		malloc (sizeof(LV2_Inline_Display));
	_impl->queue_draw->handle     = this;
	_impl->queue_draw->queue_draw = queue_draw;

	_queue_draw_feature.URI  = LV2_INLINEDISPLAY__queue_draw;
	_queue_draw_feature.data = _impl->queue_draw;
	_features[n_features++]  = &_queue_draw_feature;

	_impl->midnam = (LV2_Midnam*)
		malloc (sizeof(LV2_Midnam));
	_impl->midnam->handle = this;
	_impl->midnam->update = midnam_update;

	_midnam_feature.URI  = LV2_MIDNAM__update;
	_midnam_feature.data = _impl->midnam;
	_features[n_features++]  = &_midnam_feature;
#endif

#ifdef HAVE_LV2_1_2_0
	LV2_URID atom_Int = _uri_map.uri_to_id(LV2_ATOM__Int);
	static const int32_t _min_block_length = 1;   // may happen during split-cycles
	static const int32_t _max_block_length = 8192; // max possible (with all engines and during export)
	/* Consider updating max-block-size whenever the buffersize changes.
	 * It requires re-instantiating the plugin (which is a non-realtime operation),
	 * so it should be done lightly and only for plugins that require it.
	 *
	 * given that the block-size can change at any time (split-cycles) ardour currently
	 * does not support plugins that require bufz_fixedBlockLength.
	 */
	LV2_Options_Option options[] = {
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id(LV2_BUF_SIZE__minBlockLength),
		  sizeof(int32_t), atom_Int, &_min_block_length },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id(LV2_BUF_SIZE__maxBlockLength),
		  sizeof(int32_t), atom_Int, &_max_block_length },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id(LV2_BUF_SIZE__sequenceSize),
		  sizeof(int32_t), atom_Int, &_seq_size },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id("http://lv2plug.in/ns/ext/buf-size#nominalBlockLength"),
		  sizeof(int32_t), atom_Int, &_impl->block_length },
		{ LV2_OPTIONS_INSTANCE, 0, 0, 0, 0, NULL }
	};

	_impl->options = (LV2_Options_Option*) malloc (sizeof (options));
	memcpy ((void*) _impl->options, (void*) options, sizeof (options));

	_options_feature.URI    = LV2_OPTIONS__options;
	_options_feature.data   = _impl->options;
	_features[n_features++] = &_options_feature;
#endif

	LV2_State_Make_Path* make_path = (LV2_State_Make_Path*)malloc(
		sizeof(LV2_State_Make_Path));
	make_path->handle = this;
	make_path->path = &lv2_state_make_path;
	_make_path_feature.data = make_path;

	LV2_Log_Log* log = (LV2_Log_Log*)malloc(sizeof(LV2_Log_Log));
	log->handle  = this;
	log->printf  = &log_printf;
	log->vprintf = &log_vprintf;
	_log_feature.data = log;

	const size_t ring_size = _session.engine().raw_buffer_size(DataType::MIDI) * NBUFS;
	LilvNode* worker_schedule = lilv_new_uri(_world.world, LV2_WORKER__schedule);
	if (lilv_plugin_has_feature(plugin, worker_schedule)) {
		LV2_Worker_Schedule* schedule = (LV2_Worker_Schedule*)malloc(
			sizeof(LV2_Worker_Schedule));
		_worker                     = new Worker(this, ring_size);
		schedule->handle            = _worker;
		schedule->schedule_work     = work_schedule;
		_work_schedule_feature.data = schedule;
		_features[n_features++]     = &_work_schedule_feature;
	}
	lilv_node_free(worker_schedule);

	if (_has_state_interface) {
		// Create a non-threaded worker for use by state restore
		_state_worker = new Worker(this, ring_size, false);
	}

	_impl->instance = lilv_plugin_instantiate(plugin, rate, _features);
	_impl->name     = lilv_plugin_get_name(plugin);
	_impl->author   = lilv_plugin_get_author_name(plugin);

	if (_impl->instance == 0) {
		error << _("LV2: Failed to instantiate plugin ") << uri() << endmsg;
		throw failed_constructor();
	}

	_instance_access_feature.data              = (void*)_impl->instance->lv2_handle;
	_data_access_extension_data.extension_data = _impl->instance->lv2_descriptor->extension_data;
	_data_access_feature.data                  = &_data_access_extension_data;

	LilvNode* worker_iface_uri = lilv_new_uri(_world.world, LV2_WORKER__interface);
	if (lilv_plugin_has_extension_data(plugin, worker_iface_uri)) {
		_impl->work_iface = (const LV2_Worker_Interface*)extension_data(
			LV2_WORKER__interface);
	}
	lilv_node_free(worker_iface_uri);


#ifdef HAVE_LV2_1_2_0
	LilvNode* options_iface_uri = lilv_new_uri(_world.world, LV2_OPTIONS__interface);
	if (lilv_plugin_has_extension_data(plugin, options_iface_uri)) {
		_impl->opts_iface = (const LV2_Options_Interface*)extension_data(
			LV2_OPTIONS__interface);
	}
	lilv_node_free(options_iface_uri);
#endif

#ifdef LV2_EXTENDED
	_display_interface = (const LV2_Inline_Display_Interface*)
		extension_data (LV2_INLINEDISPLAY__interface);

	_midname_interface = (const LV2_Midnam_Interface*)
		extension_data (LV2_MIDNAM__interface);
	if (_midname_interface) {
		read_midnam ();
	}
#endif

	if (lilv_plugin_has_feature(plugin, _world.lv2_inPlaceBroken)) {
		error << string_compose(
		    _("LV2: \"%1\" cannot be used, since it cannot do inplace processing."),
		    lilv_node_as_string(_impl->name)) << endmsg;
		lilv_node_free(_impl->name);
		lilv_node_free(_impl->author);
		throw failed_constructor();
	}

#ifdef HAVE_LV2_1_2_0
	LilvNodes *required_features = lilv_plugin_get_required_features (plugin);
	if (lilv_nodes_contains (required_features, _world.bufz_powerOf2BlockLength) ||
			lilv_nodes_contains (required_features, _world.bufz_fixedBlockLength)
	   ) {
		error << string_compose(
		    _("LV2: \"%1\" buffer-size requirements cannot be satisfied."),
		    lilv_node_as_string(_impl->name)) << endmsg;
		lilv_node_free(_impl->name);
		lilv_node_free(_impl->author);
		lilv_nodes_free(required_features);
		throw failed_constructor();
	}
	lilv_nodes_free(required_features);
#endif

	LilvNodes* optional_features = lilv_plugin_get_optional_features (plugin);
#ifdef HAVE_LV2_1_2_0
	if (lilv_nodes_contains (optional_features, _world.bufz_coarseBlockLength)) {
		_no_sample_accurate_ctrl = true;
	}
#endif
#ifdef LV2_EXTENDED
	if (lilv_nodes_contains (optional_features, _world.lv2_noSampleAccurateCtrl)) {
		/* deprecated 2016-Sep-18 in favor of bufz_coarseBlockLength */
		_no_sample_accurate_ctrl = true;
	}
	if (lilv_nodes_contains (optional_features, _world.auto_can_write_automatation)) {
		_can_write_automation = true;
	}
	lilv_nodes_free(optional_features);
#endif

#ifdef HAVE_LILV_0_16_0
	// Load default state
	if (_worker) {
		/* immediately schedule any work,
		 * so that state restore later will not find a busy
		 * worker.  latency_compute_run() flushes any replies
		 */
		_worker->set_synchronous(true);
	}
	LilvState* state = lilv_state_new_from_world(
		_world.world, _uri_map.urid_map(), lilv_plugin_get_uri(_impl->plugin));
	if (state && _has_state_interface) {
		lilv_state_restore(state, _impl->instance, NULL, NULL, 0, NULL);
	}
	lilv_state_free(state);
#endif

	_sample_rate = rate;

	const uint32_t num_ports = this->num_ports();
	for (uint32_t i = 0; i < num_ports; ++i) {
		const LilvPort* port  = lilv_plugin_get_port_by_index(_impl->plugin, i);
		PortFlags       flags = 0;
		size_t          minimumSize = 0;

		if (lilv_port_is_a(_impl->plugin, port, _world.lv2_OutputPort)) {
			flags |= PORT_OUTPUT;
		} else if (lilv_port_is_a(_impl->plugin, port, _world.lv2_InputPort)) {
			flags |= PORT_INPUT;
		} else {
			error << string_compose(
				"LV2: \"%1\" port %2 is neither input nor output",
				lilv_node_as_string(_impl->name), i) << endmsg;
			throw failed_constructor();
		}

		if (lilv_port_is_a(_impl->plugin, port, _world.lv2_ControlPort)) {
			flags |= PORT_CONTROL;
		} else if (lilv_port_is_a(_impl->plugin, port, _world.lv2_AudioPort)) {
			flags |= PORT_AUDIO;
		} else if (lilv_port_is_a(_impl->plugin, port, _world.ev_EventPort)) {
			flags |= PORT_EVENT;
			flags |= PORT_MIDI;  // We assume old event API ports are for MIDI
		} else if (lilv_port_is_a(_impl->plugin, port, _world.atom_AtomPort)) {
			LilvNodes* buffer_types = lilv_port_get_value(
				_impl->plugin, port, _world.atom_bufferType);
			LilvNodes* atom_supports = lilv_port_get_value(
				_impl->plugin, port, _world.atom_supports);

			if (lilv_nodes_contains(buffer_types, _world.atom_Sequence)) {
				flags |= PORT_SEQUENCE;
				if (lilv_nodes_contains(atom_supports, _world.midi_MidiEvent)) {
					flags |= PORT_MIDI;
				}
				if (lilv_nodes_contains(atom_supports, _world.time_Position)) {
					flags |= PORT_POSITION;
				}
#ifdef LV2_EXTENDED
				if (lilv_nodes_contains(atom_supports, _world.auto_automation_control)) {
					flags |= PORT_AUTOCTRL;
				}
#endif
				if (lilv_nodes_contains(atom_supports, _world.patch_Message)) {
					flags |= PORT_PATCHMSG;
					if (flags & PORT_INPUT) {
						_patch_port_in_index = i;
					} else {
						_patch_port_out_index = i;
					}
				}
			}
			LilvNodes* min_size_v = lilv_port_get_value(_impl->plugin, port, _world.rsz_minimumSize);
			LilvNode* min_size = min_size_v ? lilv_nodes_get_first(min_size_v) : NULL;
			if (min_size && lilv_node_is_int(min_size)) {
				minimumSize = lilv_node_as_int(min_size);
			}
			lilv_nodes_free(min_size_v);
			lilv_nodes_free(buffer_types);
			lilv_nodes_free(atom_supports);
		} else {
			error << string_compose(
				"LV2: \"%1\" port %2 has no known data type",
				lilv_node_as_string(_impl->name), i) << endmsg;
			throw failed_constructor();
		}

		if ((flags & PORT_INPUT) && (flags & PORT_CONTROL)) {
			if (lilv_port_has_property(_impl->plugin, port, _world.ext_causesArtifacts)) {
				flags |= PORT_NOAUTO;
			}
			if (lilv_port_has_property(_impl->plugin, port, _world.ext_notAutomatic)) {
				flags |= PORT_NOAUTO;
			}
			if (lilv_port_has_property(_impl->plugin, port, _world.ext_expensive)) {
				flags |= PORT_NOAUTO;
			}
		}
#ifdef LV2_EXTENDED
		if (lilv_port_has_property(_impl->plugin, port, _world.auto_automation_controlled)) {
			if ((flags & PORT_INPUT) && (flags & PORT_CONTROL)) {
				flags |= PORT_CTRLED;
			}
		}
		if (lilv_port_has_property(_impl->plugin, port, _world.auto_automation_controller)) {
			if ((flags & PORT_INPUT) && (flags & PORT_CONTROL)) {
				flags |= PORT_CTRLER;
			}
		}
#endif

		_port_flags.push_back(flags);
		_port_minimumSize.push_back(minimumSize);
		DEBUG_TRACE(DEBUG::LV2, string_compose("port %1 buffer %2 bytes\n", i, minimumSize));
	}

	_control_data = new float[num_ports];
	_shadow_data  = new float[num_ports];
	_defaults     = new float[num_ports];
	_ev_buffers   = new LV2_Evbuf*[num_ports];
	memset(_ev_buffers, 0, sizeof(LV2_Evbuf*) * num_ports);

	const bool     latent        = lilv_plugin_has_latency(plugin);
	const uint32_t latency_index = (latent)
		? lilv_plugin_get_latency_port_index(plugin)
		: 0;

	// Build an array of pointers to special parameter buffers
	void*** params = new void**[num_ports];
	for (uint32_t i = 0; i < num_ports; ++i) {
		params[i] = NULL;
	}
	_impl->designated_input (LV2_TIME__beatsPerMinute, params, (void**)&_bpm_control_port);
	_impl->designated_input (LV2_CORE__freeWheeling, params, (void**)&_freewheel_control_port);

	for (uint32_t i = 0; i < num_ports; ++i) {
		const LilvPort* port = lilv_plugin_get_port_by_index(plugin, i);
		const LilvNode* sym  = lilv_port_get_symbol(plugin, port);

		// Store index in map so we can look up index by symbol
		_port_indices.insert(std::make_pair(lilv_node_as_string(sym), i));

		// Get range and default value if applicable
		if (parameter_is_control(i)) {
			LilvNode* def;
			lilv_port_get_range(plugin, port, &def, NULL, NULL);
			_defaults[i] = def ? lilv_node_as_float(def) : 0.0f;
			if (lilv_port_has_property (plugin, port, _world.lv2_sampleRate)) {
				_defaults[i] *= _session.frame_rate ();
			}
			lilv_node_free(def);

			lilv_instance_connect_port(_impl->instance, i, &_control_data[i]);

			if (latent && i == latency_index) {
				LilvNode *max;
				lilv_port_get_range(_impl->plugin, port, NULL, NULL, &max);
				_max_latency = max ? lilv_node_as_float(max) : .02 * _sample_rate;
				_latency_control_port  = &_control_data[i];
				*_latency_control_port = 0;
			}

			if (parameter_is_input(i)) {
				_shadow_data[i] = default_value(i);
				if (params[i]) {
					*params[i] = (void*)&_shadow_data[i];
				}
			}
		} else {
			_defaults[i] = 0.0f;
		}
	}

	delete[] params;

	LilvUIs* uis = lilv_plugin_get_uis(plugin);
	if (lilv_uis_size(uis) > 0) {
#ifdef HAVE_SUIL
		// Look for embeddable UI
		LILV_FOREACH(uis, u, uis) {
			const LilvUI*   this_ui      = lilv_uis_get(uis, u);
			const LilvNode* this_ui_type = NULL;
			if (lilv_ui_is_supported(this_ui,
			                         suil_ui_supported,
			                         _world.ui_GtkUI,
			                         &this_ui_type)) {
				// TODO: Multiple UI support
				_impl->ui      = this_ui;
				_impl->ui_type = this_ui_type;
				break;
			}
		}
#else
		// Look for Gtk native UI
		LILV_FOREACH(uis, i, uis) {
			const LilvUI* ui = lilv_uis_get(uis, i);
			if (lilv_ui_is_a(ui, _world.ui_GtkUI)) {
				_impl->ui      = ui;
				_impl->ui_type = _world.ui_GtkUI;
				break;
			}
		}
#endif

		// If Gtk UI is not available, try to find external UI
		if (!_impl->ui) {
			LILV_FOREACH(uis, i, uis) {
				const LilvUI* ui = lilv_uis_get(uis, i);
				if (lilv_ui_is_a(ui, _world.ui_externalkx)) {
					_impl->ui      = ui;
					_impl->ui_type = _world.ui_external;
					break;
				}
				if (lilv_ui_is_a(ui, _world.ui_external)) {
					_impl->ui      = ui;
					_impl->ui_type = _world.ui_external;
				}
			}
		}
	}

	load_supported_properties(_property_descriptors);
	allocate_atom_event_buffers();
	latency_compute_run();
}

int
LV2Plugin::set_block_size (pframes_t nframes)
{
#ifdef HAVE_LV2_1_2_0
	if (_impl->opts_iface) {
		LV2_URID atom_Int = _uri_map.uri_to_id(LV2_ATOM__Int);
		_impl->block_length = nframes;
		LV2_Options_Option block_size_option = {
			LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id ("http://lv2plug.in/ns/ext/buf-size#nominalBlockLength"),
			sizeof(int32_t), atom_Int, (void*)&_impl->block_length
		};
		_impl->opts_iface->set (_impl->instance->lv2_handle, &block_size_option);
	}
#endif
	return 0;
}

bool
LV2Plugin::requires_fixed_sized_buffers () const
{
	/* This controls if Ardour will split the plugin's run()
	 * on automation events in order to pass sample-accurate automation
	 * via standard control-ports.
	 *
	 * When returning true Ardour will *not* sub-divide the process-cycle.
	 * Automation events that happen between cycle-start and cycle-end will be
	 * ignored (ctrl values are interpolated to cycle-start).
	 * NB. Atom Sequences are still sample accurate.
	 *
	 * Note: This does not guarantee a fixed block-size.
	 * e.g The process cycle may be split when looping, also
	 * the period-size may change any time: see set_block_size()
	 */
	if (get_info()->n_inputs.n_midi() > 0) {
		/* we don't yet implement midi buffer offsets (for split cycles).
		 * Also connect_and_run() also uses _session.transport_frame() directly
		 * (for BBT) which is not offset for plugin cycle split.
		 */
		return true;
	}
	return _no_sample_accurate_ctrl;
}

LV2Plugin::~LV2Plugin ()
{
	DEBUG_TRACE(DEBUG::LV2, string_compose("%1 destroy\n", name()));

	deactivate();
	cleanup();

#ifdef LV2_EXTENDED
	if (has_midnam ()) {
		std::stringstream ss;
		ss << (void*)this;
		ss << unique_id();
		MIDI::Name::MidiPatchManager::instance().remove_custom_midnam (ss.str());
	}
#endif

	lilv_instance_free(_impl->instance);
	lilv_state_free(_impl->state);
	lilv_node_free(_impl->name);
	lilv_node_free(_impl->author);
#ifdef HAVE_LV2_1_2_0
	free(_impl->options);
#endif
#ifdef LV2_EXTENDED
	free(_impl->queue_draw);
	free(_impl->midnam);
#endif

	free(_features);
	free(_log_feature.data);
	free(_make_path_feature.data);
	free(_work_schedule_feature.data);

	delete _to_ui;
	delete _from_ui;
	delete _worker;
	delete _state_worker;

	if (_atom_ev_buffers) {
		LV2_Evbuf**  b = _atom_ev_buffers;
		while (*b) {
			free(*b);
			b++;
		}
		free(_atom_ev_buffers);
	}

	delete [] _control_data;
	delete [] _shadow_data;
	delete [] _defaults;
	delete [] _ev_buffers;
	delete _impl;
}

bool
LV2Plugin::is_external_ui() const
{
	if (!_impl->ui) {
		return false;
	}
	return lilv_ui_is_a(_impl->ui, _world.ui_external) || lilv_ui_is_a(_impl->ui, _world.ui_externalkx);
}

bool
LV2Plugin::is_external_kx() const
{
	if (!_impl->ui) {
		return false;
	}
	return lilv_ui_is_a(_impl->ui, _world.ui_externalkx);
}

bool
LV2Plugin::ui_is_resizable () const
{
	const LilvNode* s   = lilv_ui_get_uri(_impl->ui);
	LilvNode*       p   = lilv_new_uri(_world.world, LV2_CORE__optionalFeature);
	LilvNode*       fs  = lilv_new_uri(_world.world, LV2_UI__fixedSize);
	LilvNode*       nrs = lilv_new_uri(_world.world, LV2_UI__noUserResize);

	LilvNodes* fs_matches = lilv_world_find_nodes(_world.world, s, p, fs);
	LilvNodes* nrs_matches = lilv_world_find_nodes(_world.world, s, p, nrs);

	lilv_nodes_free(nrs_matches);
	lilv_nodes_free(fs_matches);
	lilv_node_free(nrs);
	lilv_node_free(fs);
	lilv_node_free(p);

	return !fs_matches && !nrs_matches;
}

#ifdef LV2_EXTENDED
bool
LV2Plugin::has_inline_display () {
	return _display_interface ? true : false;
}

Plugin::Display_Image_Surface*
LV2Plugin::render_inline_display (uint32_t w, uint32_t h) {
	if (_display_interface) {
		/* Plugin::Display_Image_Surface is identical to
		 * LV2_Inline_Display_Image_Surface */
		return (Plugin::Display_Image_Surface*) _display_interface->render ((void*)_impl->instance->lv2_handle, w, h);
	}
	return NULL;
}

bool
LV2Plugin::has_midnam () {
	return _midname_interface ? true : false;
}

bool
LV2Plugin::read_midnam () {
	bool rv = false;
	if (!_midname_interface) {
		return rv;
	}
	char* midnam = _midname_interface->midnam ((void*)_impl->instance->lv2_handle);
	if (midnam) {
		std::stringstream ss;
		ss << (void*)this;
		ss << unique_id();
		rv = MIDI::Name::MidiPatchManager::instance().update_custom_midnam (ss.str(), midnam);
	}
#ifndef NDEBUG
	if (rv) {
		info << string_compose(_("LV2: update midnam for plugin '%1'"), name ()) << endmsg;
	} else {
		warning << string_compose(_("LV2: Failed to parse midnam of plugin '%1'"), name ()) << endmsg;
	}
#endif
	_midname_interface->free (midnam);
	return rv;
}

std::string
LV2Plugin::midnam_model () {
	std::string rv;
	if (!_midname_interface) {
		return rv;
	}
	char* model = _midname_interface->model ((void*)_impl->instance->lv2_handle);
	if (model) {
		rv = model;
	}
	_midname_interface->free (model);
	return rv;
}
#endif

string
LV2Plugin::unique_id() const
{
	return lilv_node_as_uri(lilv_plugin_get_uri(_impl->plugin));
}

const char*
LV2Plugin::uri() const
{
	return lilv_node_as_uri(lilv_plugin_get_uri(_impl->plugin));
}

const char*
LV2Plugin::label() const
{
	return lilv_node_as_string(_impl->name);
}

const char*
LV2Plugin::name() const
{
	return lilv_node_as_string(_impl->name);
}

const char*
LV2Plugin::maker() const
{
	return _impl->author ? lilv_node_as_string (_impl->author) : "Unknown";
}

uint32_t
LV2Plugin::num_ports() const
{
	return lilv_plugin_get_num_ports(_impl->plugin);
}

uint32_t
LV2Plugin::parameter_count() const
{
	return lilv_plugin_get_num_ports(_impl->plugin);
}

float
LV2Plugin::default_value(uint32_t port)
{
	return _defaults[port];
}

const char*
LV2Plugin::port_symbol(uint32_t index) const
{
	const LilvPort* port = lilv_plugin_get_port_by_index(_impl->plugin, index);
	if (!port) {
		error << name() << ": Invalid port index " << index << endmsg;
	}

	const LilvNode* sym = lilv_port_get_symbol(_impl->plugin, port);
	return lilv_node_as_string(sym);
}

uint32_t
LV2Plugin::port_index (const char* symbol) const
{
	const map<string, uint32_t>::const_iterator i = _port_indices.find(symbol);
	if (i != _port_indices.end()) {
		return  i->second;
	} else {
		warning << string_compose(_("LV2: Unknown port %1"), symbol) << endmsg;
		return (uint32_t)-1;
	}
}

void
LV2Plugin::set_parameter(uint32_t which, float val)
{
	DEBUG_TRACE(DEBUG::LV2, string_compose(
		            "%1 set parameter %2 to %3\n", name(), which, val));

	if (which < lilv_plugin_get_num_ports(_impl->plugin)) {
		if (get_parameter (which) == val) {
			return;
		}

		_shadow_data[which] = val;
	} else {
		warning << string_compose(
		    _("Illegal parameter number used with plugin \"%1\". "
		      "This is a bug in either %2 or the LV2 plugin <%3>"),
		    name(), PROGRAM_NAME, unique_id()) << endmsg;
	}

	Plugin::set_parameter(which, val);
}

float
LV2Plugin::get_parameter(uint32_t which) const
{
	if (parameter_is_input(which)) {
		return (float)_shadow_data[which];
	} else {
		return (float)_control_data[which];
	}
	return 0.0f;
}

std::string
LV2Plugin::get_docs() const
{
	LilvNodes* comments = lilv_plugin_get_value(_impl->plugin, _world.rdfs_comment);
	if (comments) {
		const std::string docs(lilv_node_as_string(lilv_nodes_get_first(comments)));
		lilv_nodes_free(comments);
		return docs;
	}

	return "";
}

std::string
LV2Plugin::get_parameter_docs(uint32_t which) const
{
	LilvNodes* comments = lilv_port_get_value(
		_impl->plugin,
		lilv_plugin_get_port_by_index(_impl->plugin, which),
		_world.rdfs_comment);

	if (comments) {
		const std::string docs(lilv_node_as_string(lilv_nodes_get_first(comments)));
		lilv_nodes_free(comments);
		return docs;
	}

	return "";
}

bool
LV2Plugin::get_layout (uint32_t which, UILayoutHint& h) const
{
	/// TODO lookup port-properties
	if (unique_id () != "urn:ardour:a-eq") {
		return false;
	}
	h.knob = true;
	switch (which) {
		case  0: h.x0 = 0; h.x1 = 1; h.y0 = 2; h.y1 = 3; break; // Frequency L
		case  1: h.x0 = 0; h.x1 = 1; h.y0 = 0; h.y1 = 1; break; // Gain L
		case 17: h.x0 = 0; h.x1 = 1; h.y0 = 5; h.y1 = 6; break; // enable L

		case  2: h.x0 = 1; h.x1 = 3; h.y0 = 2; h.y1 = 3; break; // Frequency 1
		case  3: h.x0 = 1; h.x1 = 3; h.y0 = 0; h.y1 = 1; break; // Gain 1
		case  4: h.x0 = 1; h.x1 = 3; h.y0 = 1; h.y1 = 2; break; // Bandwidth 1
		case 18: h.x0 = 1; h.x1 = 4; h.y0 = 5; h.y1 = 6; break; // enable 1

		case  5: h.x0 = 4; h.x1 = 6; h.y0 = 2; h.y1 = 3; break; // Frequency 2
		case  6: h.x0 = 4; h.x1 = 6; h.y0 = 0; h.y1 = 1; break; // Gain 2
		case  7: h.x0 = 4; h.x1 = 6; h.y0 = 1; h.y1 = 2; break; // Bandwidth 2
		case 19: h.x0 = 4; h.x1 = 7; h.y0 = 5; h.y1 = 6; break; // enable 2

		case  8: h.x0 = 7; h.x1 =  9; h.y0 = 2; h.y1 = 3; break; // Frequency 3
		case  9: h.x0 = 7; h.x1 =  9; h.y0 = 0; h.y1 = 1; break; // Gain 3
		case 10: h.x0 = 7; h.x1 =  9; h.y0 = 1; h.y1 = 2; break; // Bandwidth 3
		case 20: h.x0 = 7; h.x1 = 10; h.y0 = 5; h.y1 = 6; break; // enable 3

		case 11: h.x0 = 10; h.x1 = 12; h.y0 = 2; h.y1 = 3; break; // Frequency 4
		case 12: h.x0 = 10; h.x1 = 12; h.y0 = 0; h.y1 = 1; break; // Gain 4
		case 13: h.x0 = 10; h.x1 = 12; h.y0 = 1; h.y1 = 2; break; // Bandwidth 4
		case 21: h.x0 = 10; h.x1 = 13; h.y0 = 5; h.y1 = 6; break; // enable 4

		case 14: h.x0 = 13; h.x1 = 14; h.y0 = 2; h.y1 = 3; break; // Frequency H
		case 15: h.x0 = 13; h.x1 = 14; h.y0 = 0; h.y1 = 1; break; // Gain H
		case 22: h.x0 = 13; h.x1 = 14; h.y0 = 5; h.y1 = 6; break; // enable H

		case 16: h.x0 = 14; h.x1 = 15; h.y0 = 1; h.y1 = 3; break; // Master Gain
		case 23: h.x0 = 14; h.x1 = 15; h.y0 = 5; h.y1 = 6; break; // Master Enable
		default:
			return false;
	}
	return true;
}

uint32_t
LV2Plugin::nth_parameter(uint32_t n, bool& ok) const
{
	ok = false;
	for (uint32_t c = 0, x = 0; x < lilv_plugin_get_num_ports(_impl->plugin); ++x) {
		if (parameter_is_control(x)) {
			if (c++ == n) {
				ok = true;
				return x;
			}
		}
	}

	return 0;
}

const void*
LV2Plugin::extension_data(const char* uri) const
{
	return lilv_instance_get_extension_data(_impl->instance, uri);
}

const void*
LV2Plugin::c_plugin()
{
	return _impl->plugin;
}

const void*
LV2Plugin::c_ui()
{
	return (const void*)_impl->ui;
}

const void*
LV2Plugin::c_ui_type()
{
	return (const void*)_impl->ui_type;
}

/** Directory for all plugin state. */
const std::string
LV2Plugin::plugin_dir() const
{
	if (!_plugin_state_dir.empty ()){
		return Glib::build_filename(_plugin_state_dir, _insert_id.to_s());
	} else {
		return Glib::build_filename(_session.plugins_dir(), _insert_id.to_s());
	}
}

/** Directory for files created by the plugin (except during save). */
const std::string
LV2Plugin::scratch_dir() const
{
	return Glib::build_filename(plugin_dir(), "scratch");
}

/** Directory for snapshots of files in the scratch directory. */
const std::string
LV2Plugin::file_dir() const
{
	return Glib::build_filename(plugin_dir(), "files");
}

/** Directory to save state snapshot version @c num into. */
const std::string
LV2Plugin::state_dir(unsigned num) const
{
	return Glib::build_filename(plugin_dir(), string("state") + PBD::to_string (num));
}

/** Implementation of state:makePath for files created at instantiation time.
 * Note this is not used for files created at save time (Lilv deals with that).
 */
char*
LV2Plugin::lv2_state_make_path(LV2_State_Make_Path_Handle handle,
                               const char*                path)
{
	LV2Plugin* me = (LV2Plugin*)handle;
	if (me->_insert_id == PBD::ID("0")) {
		warning << string_compose(
			"File path \"%1\" requested but LV2 %2 has no insert ID",
			path, me->name()) << endmsg;
		return g_strdup(path);
	}

	const std::string abs_path = Glib::build_filename(me->scratch_dir(), path);
	const std::string dirname  = Glib::path_get_dirname(abs_path);
	g_mkdir_with_parents(dirname.c_str(), 0744);

	DEBUG_TRACE(DEBUG::LV2, string_compose("new file path %1 => %2\n",
	                                       path, abs_path));

	return g_strndup(abs_path.c_str(), abs_path.length());
}

void
LV2Plugin::add_state(XMLNode* root) const
{
	assert(_insert_id != PBD::ID("0"));

	XMLNode*    child;
	LocaleGuard lg;

	for (uint32_t i = 0; i < parameter_count(); ++i) {
		if (parameter_is_input(i) && parameter_is_control(i)) {
			child = new XMLNode("Port");
			child->set_property("symbol", port_symbol(i));
			child->set_property("value", _shadow_data[i]);
			root->add_child_nocopy(*child);
		}
	}

	if (!_plugin_state_dir.empty()) {
		root->set_property("template-dir", _plugin_state_dir);
	}

	if (_has_state_interface) {
		// Provisionally increment state version and create directory
		const std::string new_dir = state_dir(++_state_version);
		// and keep track of it (for templates & archive)
		unsigned int saved_state = _state_version;;
		g_mkdir_with_parents(new_dir.c_str(), 0744);

		LilvState* state = lilv_state_new_from_instance(
			_impl->plugin,
			_impl->instance,
			_uri_map.urid_map(),
			scratch_dir().c_str(),
			file_dir().c_str(),
			_session.externals_dir().c_str(),
			new_dir.c_str(),
			NULL,
			const_cast<LV2Plugin*>(this),
			0,
			NULL);

		if (!_plugin_state_dir.empty() || force_state_save
		    || !_impl->state
		    || !lilv_state_equals(state, _impl->state)) {
			lilv_state_save(_world.world,
			                _uri_map.urid_map(),
			                _uri_map.urid_unmap(),
			                state,
			                NULL,
			                new_dir.c_str(),
			                "state.ttl");

			if (force_state_save) {
				// archive or save-as
				lilv_state_free(state);
				--_state_version;
			}
			else if (_plugin_state_dir.empty()) {
				// normal session save
				lilv_state_free(_impl->state);
				_impl->state = state;
			} else {
				// template save (dedicated state-dir)
				lilv_state_free(state);
				--_state_version;
			}
		} else {
			// State is identical, decrement version and nuke directory
			lilv_state_free(state);
			PBD::remove_directory(new_dir);
			--_state_version;
			saved_state = _state_version;
		}

		root->set_property("state-dir", string("state") + PBD::to_string (saved_state));
	}
}

// TODO: Once we can rely on lilv 0.16.0, lilv_world_get can replace this
static LilvNode*
get_value(LilvWorld* world, const LilvNode* subject, const LilvNode* predicate)
{
	LilvNodes* vs = lilv_world_find_nodes(world, subject, predicate, NULL);
	if (vs) {
		LilvNode* node = lilv_node_duplicate(lilv_nodes_get_first(vs));
		lilv_nodes_free(vs);
		return node;
	}
	return NULL;
}

void
LV2Plugin::find_presets()
{
	LilvNode* lv2_appliesTo = lilv_new_uri(_world.world, LV2_CORE__appliesTo);
	LilvNode* pset_Preset   = lilv_new_uri(_world.world, LV2_PRESETS__Preset);
	LilvNode* rdfs_label    = lilv_new_uri(_world.world, LILV_NS_RDFS "label");

	LilvNodes* presets = lilv_plugin_get_related(_impl->plugin, pset_Preset);
	LILV_FOREACH(nodes, i, presets) {
		const LilvNode* preset = lilv_nodes_get(presets, i);
		lilv_world_load_resource(_world.world, preset);
		LilvNode* name = get_value(_world.world, preset, rdfs_label);
		bool userpreset = true; // TODO
		if (name) {
			_presets.insert(std::make_pair(lilv_node_as_string(preset),
			                               Plugin::PresetRecord(
				                               lilv_node_as_string(preset),
				                               lilv_node_as_string(name),
				                               userpreset)));
			lilv_node_free(name);
		} else {
			warning << string_compose(
			    _("Plugin \"%1\" preset \"%2\" is missing a label\n"),
			    lilv_node_as_string(lilv_plugin_get_uri(_impl->plugin)),
			    lilv_node_as_string(preset)) << endmsg;
		}
	}
	lilv_nodes_free(presets);

	lilv_node_free(rdfs_label);
	lilv_node_free(pset_Preset);
	lilv_node_free(lv2_appliesTo);
}

static void
set_port_value(const char* port_symbol,
               void*       user_data,
               const void* value,
               uint32_t    /*size*/,
               uint32_t    type)
{
	LV2Plugin* self = (LV2Plugin*)user_data;
	if (type != 0 && type != URIMap::instance().urids.atom_Float) {
		return;  // TODO: Support non-float ports
	}

	const uint32_t port_index = self->port_index(port_symbol);
	if (port_index != (uint32_t)-1) {
		self->set_parameter(port_index, *(const float*)value);
		self->PresetPortSetValue (port_index, *(const float*)value); /* EMIT SIGNAL */
	}
}

bool
LV2Plugin::load_preset(PresetRecord r)
{
	LilvWorld* world = _world.world;
	LilvNode*  pset  = lilv_new_uri(world, r.uri.c_str());
	LilvState* state = lilv_state_new_from_world(world, _uri_map.urid_map(), pset);

	const LV2_Feature*  state_features[2]   = { NULL, NULL };
	LV2_Worker_Schedule schedule            = { _state_worker, work_schedule };
	const LV2_Feature   state_sched_feature = { LV2_WORKER__schedule, &schedule };
	if (_state_worker) {
		state_features[0] = &state_sched_feature;
	}

	if (state) {
		lilv_state_restore(state, _impl->instance, set_port_value, this, 0, state_features);
		lilv_state_free(state);
		Plugin::load_preset(r);
	}

	lilv_node_free(pset);
	return state;
}

const void*
ARDOUR::lv2plugin_get_port_value(const char* port_symbol,
                                 void*       user_data,
                                 uint32_t*   size,
                                 uint32_t*   type)
{
	LV2Plugin *plugin = (LV2Plugin *) user_data;

	uint32_t index = plugin->port_index(port_symbol);
	if (index != (uint32_t) -1) {
		if (plugin->parameter_is_input(index) && plugin->parameter_is_control(index)) {
			float *value;
			*size = sizeof(float);
			*type = plugin->_uri_map.uri_to_id(LV2_ATOM__Float);
			value = &plugin->_shadow_data[index];

			return value;
		}
	}

	*size = *type = 0;
	return NULL;
}


std::string
LV2Plugin::do_save_preset(string name)
{
	LilvNode*    plug_name = lilv_plugin_get_name(_impl->plugin);
	const string prefix    = legalize_for_uri(lilv_node_as_string(plug_name));
	const string base_name = legalize_for_uri(name);
	const string file_name = base_name + ".ttl";
	const string bundle    = Glib::build_filename(
		Glib::get_home_dir(),
		Glib::build_filename(".lv2", prefix + "_" + base_name + ".lv2"));

#ifdef HAVE_LILV_0_21_3
	/* delete reference to old preset (if any) */
	const PresetRecord* r = preset_by_label(name);
	if (r) {
		LilvNode*  pset  = lilv_new_uri (_world.world, r->uri.c_str());
		if (pset) {
			lilv_world_unload_resource (_world.world, pset);
			lilv_node_free(pset);
		}
	}
#endif

	LilvState* state = lilv_state_new_from_instance(
		_impl->plugin,
		_impl->instance,
		_uri_map.urid_map(),
		scratch_dir().c_str(),                   // file_dir
		bundle.c_str(),                          // copy_dir
		bundle.c_str(),                          // link_dir
		bundle.c_str(),                          // save_dir
		lv2plugin_get_port_value,                // get_value
		(void*)this,                             // user_data
		LV2_STATE_IS_POD|LV2_STATE_IS_PORTABLE,  // flags
		_features                                // features
	);

	lilv_state_set_label(state, name.c_str());
	lilv_state_save(
		_world.world,           // world
		_uri_map.urid_map(),    // map
		_uri_map.urid_unmap(),  // unmap
		state,                  // state
		NULL,                   // uri (NULL = use file URI)
		bundle.c_str(),         // dir
		file_name.c_str()       // filename
	);

	lilv_state_free(state);

	std::string uri = Glib::filename_to_uri(Glib::build_filename(bundle, file_name));
	LilvNode *node_bundle = lilv_new_uri(_world.world, Glib::filename_to_uri(Glib::build_filename(bundle, "/")).c_str());
	LilvNode *node_preset = lilv_new_uri(_world.world, uri.c_str());
#ifdef HAVE_LILV_0_21_3
	lilv_world_unload_resource(_world.world, node_preset);
	lilv_world_unload_bundle(_world.world, node_bundle);
#endif
	lilv_world_load_bundle(_world.world, node_bundle);
	lilv_world_load_resource(_world.world, node_preset);
	lilv_node_free(node_bundle);
	lilv_node_free(node_preset);
	lilv_node_free(plug_name);
	return uri;
}

void
LV2Plugin::do_remove_preset(string name)
{
#ifdef HAVE_LILV_0_21_3
	/* Look up preset record by label (FIXME: ick, label as ID) */
	const PresetRecord* r = preset_by_label(name);
	if (!r) {
		return;
	}

	/* Load a LilvState for the preset. */
	LilvWorld* world = _world.world;
	LilvNode*  pset  = lilv_new_uri(world, r->uri.c_str());
	LilvState* state = lilv_state_new_from_world(world, _uri_map.urid_map(), pset);
	if (!state) {
		lilv_node_free(pset);
		return;
	}

	/* Unload preset from world. */
	lilv_world_unload_resource(world, pset);

	/* Delete it from the file system.  This will remove the preset file and the entry
	   from the manifest.  If this results in an empty manifest (i.e. the
	   preset is the only thing in the bundle), then the bundle is removed. */
	lilv_state_delete(world, state);

	lilv_state_free(state);
	lilv_node_free(pset);
#endif
	/* Without lilv_state_delete(), we could delete the preset file, but this
	   would leave a broken bundle/manifest around, so the preset would still
	   be visible, but broken.  Naively deleting a bundle is too dangerous, so
	   we simply do not support preset deletion with older Lilv */
}

bool
LV2Plugin::has_editor() const
{
	return _impl->ui != NULL;
}

bool
LV2Plugin::has_message_output() const
{
	for (uint32_t i = 0; i < num_ports(); ++i) {
		if ((_port_flags[i] & PORT_SEQUENCE) &&
		    (_port_flags[i] & PORT_OUTPUT)) {
			return true;
		}
	}
	return false;
}

bool
LV2Plugin::write_to(RingBuffer<uint8_t>* dest,
                    uint32_t             index,
                    uint32_t             protocol,
                    uint32_t             size,
                    const uint8_t*       body)
{
	const uint32_t  buf_size = sizeof(UIMessage) + size;
	vector<uint8_t> buf(buf_size);

	UIMessage* msg = (UIMessage*)&buf[0];
	msg->index    = index;
	msg->protocol = protocol;
	msg->size     = size;
	memcpy(msg + 1, body, size);

	return (dest->write(&buf[0], buf_size) == buf_size);
}

bool
LV2Plugin::write_from_ui(uint32_t       index,
                         uint32_t       protocol,
                         uint32_t       size,
                         const uint8_t* body)
{
	if (!_from_ui) {
		size_t rbs = _session.engine().raw_buffer_size(DataType::MIDI) * NBUFS;
		/* buffer data communication from plugin UI to plugin instance.
		 * this buffer needs to potentially hold
		 *   (port's minimumSize) * (audio-periods) / (UI-periods)
		 * bytes.
		 *
		 *  e.g 48kSPS / 128fpp -> audio-periods = 375 Hz
		 *  ui-periods = 25 Hz (SuperRapidScreenUpdate)
		 *  default minimumSize = 32K (see LV2Plugin::allocate_atom_event_buffers()
		 *
		 * it is NOT safe to overflow (msg.size will be misinterpreted)
		 */
		uint32_t bufsiz = 32768;
		if (_atom_ev_buffers && _atom_ev_buffers[0]) {
			bufsiz =  lv2_evbuf_get_capacity(_atom_ev_buffers[0]);
		}
		int fact = ceilf(_session.frame_rate () / 3000.f);
		rbs = max((size_t) bufsiz * std::max (8, fact), rbs);
		_from_ui = new RingBuffer<uint8_t>(rbs);
	}

	if (!write_to(_from_ui, index, protocol, size, body)) {
		error << "Error writing from UI to plugin" << endmsg;
		return false;
	}
	return true;
}

bool
LV2Plugin::write_to_ui(uint32_t       index,
                       uint32_t       protocol,
                       uint32_t       size,
                       const uint8_t* body)
{
	if (!write_to(_to_ui, index, protocol, size, body)) {
		error << "Error writing from plugin to UI" << endmsg;
		return false;
	}
	return true;
}

static void
forge_variant(LV2_Atom_Forge* forge, const Variant& value)
{
	switch (value.type()) {
	case Variant::NOTHING:
		break;
	case Variant::BEATS:
		// No atom type for this, just forge a double
		lv2_atom_forge_double(forge, value.get_beats().to_double());
		break;
	case Variant::BOOL:
		lv2_atom_forge_bool(forge, value.get_bool());
		break;
	case Variant::DOUBLE:
		lv2_atom_forge_double(forge, value.get_double());
		break;
	case Variant::FLOAT:
		lv2_atom_forge_float(forge, value.get_float());
		break;
	case Variant::INT:
		lv2_atom_forge_int(forge, value.get_int());
		break;
	case Variant::LONG:
		lv2_atom_forge_long(forge, value.get_long());
		break;
	case Variant::PATH:
		lv2_atom_forge_path(
			forge, value.get_path().c_str(), value.get_path().size());
		break;
	case Variant::STRING:
		lv2_atom_forge_string(
			forge, value.get_string().c_str(), value.get_string().size());
		break;
	case Variant::URI:
		lv2_atom_forge_uri(
			forge, value.get_uri().c_str(), value.get_uri().size());
		break;
	}
}

/** Get a variant type from a URI, return false iff no match found. */
static bool
uri_to_variant_type(const std::string& uri, Variant::Type& type)
{
	if (uri == LV2_ATOM__Bool) {
		type = Variant::BOOL;
	} else if (uri == LV2_ATOM__Double) {
		type = Variant::DOUBLE;
	} else if (uri == LV2_ATOM__Float) {
		type = Variant::FLOAT;
	} else if (uri == LV2_ATOM__Int) {
		type = Variant::INT;
	} else if (uri == LV2_ATOM__Long) {
		type = Variant::LONG;
	} else if (uri == LV2_ATOM__Path) {
		type = Variant::PATH;
	} else if (uri == LV2_ATOM__String) {
		type = Variant::STRING;
	} else if (uri == LV2_ATOM__URI) {
		type = Variant::URI;
	} else {
		return false;
	}
	return true;
}

void
LV2Plugin::set_property(uint32_t key, const Variant& value)
{
	if (_patch_port_in_index == (uint32_t)-1) {
		error << "LV2: set_property called with unset patch_port_in_index" << endmsg;
		return;
	} else if (value.type() == Variant::NOTHING) {
		error << "LV2: set_property called with void value" << endmsg;
		return;
	}

	// Set up forge to write to temporary buffer on the stack
	LV2_Atom_Forge*      forge = &_impl->ui_forge;
	LV2_Atom_Forge_Frame frame;
	uint8_t              buf[PATH_MAX];  // Ought to be enough for anyone...

	lv2_atom_forge_set_buffer(forge, buf, sizeof(buf));

	// Serialize patch:Set message to set property
#ifdef HAVE_LV2_1_10_0
	lv2_atom_forge_object(forge, &frame, 0, _uri_map.urids.patch_Set);
	lv2_atom_forge_key(forge, _uri_map.urids.patch_property);
	lv2_atom_forge_urid(forge, key);
	lv2_atom_forge_key(forge, _uri_map.urids.patch_value);
#else
	lv2_atom_forge_blank(forge, &frame, 0, _uri_map.urids.patch_Set);
	lv2_atom_forge_property_head(forge, _uri_map.urids.patch_property, 0);
	lv2_atom_forge_urid(forge, key);
	lv2_atom_forge_property_head(forge, _uri_map.urids.patch_value, 0);
#endif

	forge_variant(forge, value);

	// Write message to UI=>Plugin ring
	const LV2_Atom* const atom = (const LV2_Atom*)buf;
	write_from_ui(_patch_port_in_index,
	              _uri_map.urids.atom_eventTransfer,
	              lv2_atom_total_size(atom),
	              (const uint8_t*)atom);
}

const ParameterDescriptor&
LV2Plugin::get_property_descriptor(uint32_t id) const
{
	PropertyDescriptors::const_iterator p = _property_descriptors.find(id);
	if (p != _property_descriptors.end()) {
		return p->second;
	}
	return Plugin::get_property_descriptor(id);
}

static void
load_parameter_descriptor_units(LilvWorld* lworld, ParameterDescriptor& desc, const LilvNodes* units)
{
	if (lilv_nodes_contains(units, _world.units_midiNote)) {
		desc.unit = ParameterDescriptor::MIDI_NOTE;
	} else if (lilv_nodes_contains(units, _world.units_db)) {
		desc.unit = ParameterDescriptor::DB;
	} else if (lilv_nodes_contains(units, _world.units_hz)) {
		desc.unit = ParameterDescriptor::HZ;
	}
	if (lilv_nodes_size(units) > 0) {
		const LilvNode* unit = lilv_nodes_get_first(units);
		LilvNode* render = get_value(lworld, unit, _world.units_render);
		if (render) {
			desc.print_fmt = lilv_node_as_string(render);
			/* override lilv's default "%f" format */
			if (desc.integer_step) {
				replace_all (desc.print_fmt, "%f", "%d");
			} else if (desc.upper - desc.lower >= 1000) {
				replace_all (desc.print_fmt, "%f", "%.1f");
			} else if (desc.upper - desc.lower >= 100) {
				replace_all (desc.print_fmt, "%f", "%.2f");
			} else {
				replace_all (desc.print_fmt, "%f", "%.3f");
			}
			lilv_node_free(render);
		}
	}
}

static void
load_parameter_descriptor(LV2World&            world,
                          ParameterDescriptor& desc,
                          Variant::Type        datatype,
                          const LilvNode*      subject)
{
	LilvWorld* lworld  = _world.world;
	LilvNode*  label   = get_value(lworld, subject, _world.rdfs_label);
	LilvNode*  def     = get_value(lworld, subject, _world.lv2_default);
	LilvNode*  minimum = get_value(lworld, subject, _world.lv2_minimum);
	LilvNode*  maximum = get_value(lworld, subject, _world.lv2_maximum);
	LilvNodes* units   = lilv_world_find_nodes(lworld, subject, _world.units_unit, NULL);
	if (label) {
		desc.label = lilv_node_as_string(label);
	}
	if (def) {
		if (lilv_node_is_float(def)) {
			desc.normal = lilv_node_as_float(def);
		} else if (lilv_node_is_int(def)) {
			desc.normal = lilv_node_as_int(def);
		}
	}
	if (minimum) {
		if (lilv_node_is_float(minimum)) {
			desc.lower = lilv_node_as_float(minimum);
		} else if (lilv_node_is_int(minimum)) {
			desc.lower = lilv_node_as_int(minimum);
		}
	}
	if (maximum) {
		if (lilv_node_is_float(maximum)) {
			desc.upper = lilv_node_as_float(maximum);
		} else if (lilv_node_is_int(maximum)) {
			desc.upper = lilv_node_as_int(maximum);
		}
	}
	load_parameter_descriptor_units(lworld, desc, units);
	desc.datatype      = datatype;
	desc.toggled      |= datatype == Variant::BOOL;
	desc.integer_step |= datatype == Variant::INT || datatype == Variant::LONG;
	desc.update_steps();

	lilv_nodes_free(units);
	lilv_node_free(label);
	lilv_node_free(def);
	lilv_node_free(minimum);
	lilv_node_free(maximum);
}

void
LV2Plugin::load_supported_properties(PropertyDescriptors& descs)
{
	LilvWorld*       lworld     = _world.world;
	const LilvNode*  subject    = lilv_plugin_get_uri(_impl->plugin);
	LilvNodes*       properties = lilv_world_find_nodes(
		lworld, subject, _world.patch_writable, NULL);
	LILV_FOREACH(nodes, p, properties) {
		// Get label and range
		const LilvNode* prop  = lilv_nodes_get(properties, p);
		LilvNode*       range = get_value(lworld, prop, _world.rdfs_range);
		if (!range) {
			warning << string_compose(_("LV2: property <%1> has no range datatype, ignoring"),
			                          lilv_node_as_uri(prop)) << endmsg;
			continue;
		}

		// Convert range to variant type (TODO: support for multiple range types)
		Variant::Type datatype;
		if (!uri_to_variant_type(lilv_node_as_uri(range), datatype)) {
			error << string_compose(_("LV2: property <%1> has unsupported datatype <%1>"),
			                        lilv_node_as_uri(prop), lilv_node_as_uri(range)) << endmsg;
			continue;
		}

		// Add description to result
		ParameterDescriptor desc;
		desc.key      = _uri_map.uri_to_id(lilv_node_as_uri(prop));
		desc.datatype = datatype;
		load_parameter_descriptor(_world, desc, datatype, prop);
		descs.insert(std::make_pair(desc.key, desc));

		lilv_node_free(range);
	}
	lilv_nodes_free(properties);
}

void
LV2Plugin::announce_property_values()
{
	if (_patch_port_in_index == (uint32_t)-1) {
		return;
	}

	// Set up forge to write to temporary buffer on the stack
	LV2_Atom_Forge*      forge = &_impl->ui_forge;
	LV2_Atom_Forge_Frame frame;
	uint8_t              buf[PATH_MAX];  // Ought to be enough for anyone...

	lv2_atom_forge_set_buffer(forge, buf, sizeof(buf));

	// Serialize patch:Get message with no subject (implicitly plugin instance)
#ifdef HAVE_LV2_1_10_0
	lv2_atom_forge_object(forge, &frame, 0, _uri_map.urids.patch_Get);
#else
	lv2_atom_forge_blank(forge, &frame, 0, _uri_map.urids.patch_Get);
#endif

	// Write message to UI=>Plugin ring
	const LV2_Atom* const atom = (const LV2_Atom*)buf;
	write_from_ui(_patch_port_in_index,
	              _uri_map.urids.atom_eventTransfer,
	              lv2_atom_total_size(atom),
	              (const uint8_t*)atom);
}

void
LV2Plugin::enable_ui_emission()
{
	if (!_to_ui) {
		/* see note in LV2Plugin::write_from_ui() */
		uint32_t bufsiz = 32768;
		if (_atom_ev_buffers && _atom_ev_buffers[0]) {
			bufsiz =  lv2_evbuf_get_capacity(_atom_ev_buffers[0]);
		}
		size_t rbs = _session.engine().raw_buffer_size(DataType::MIDI) * NBUFS;
		rbs = max((size_t) bufsiz * 8, rbs);
		_to_ui = new RingBuffer<uint8_t>(rbs);
	}
}

void
LV2Plugin::emit_to_ui(void* controller, UIMessageSink sink)
{
	if (!_to_ui) {
		return;
	}

	uint32_t read_space = _to_ui->read_space();
	while (read_space > sizeof(UIMessage)) {
		UIMessage msg;
		if (_to_ui->read((uint8_t*)&msg, sizeof(msg)) != sizeof(msg)) {
			error << "Error reading from Plugin=>UI RingBuffer" << endmsg;
			break;
		}
		vector<uint8_t> body(msg.size);
		if (_to_ui->read(&body[0], msg.size) != msg.size) {
			error << "Error reading from Plugin=>UI RingBuffer" << endmsg;
			break;
		}

		sink(controller, msg.index, msg.size, msg.protocol, &body[0]);

		read_space -= sizeof(msg) + msg.size;
	}
}

int
LV2Plugin::work(Worker& worker, uint32_t size, const void* data)
{
	Glib::Threads::Mutex::Lock lm(_work_mutex);
	return _impl->work_iface->work(
		_impl->instance->lv2_handle, work_respond, &worker, size, data);
}

int
LV2Plugin::work_response(uint32_t size, const void* data)
{
	return _impl->work_iface->work_response(
		_impl->instance->lv2_handle, size, data);
}

void
LV2Plugin::set_insert_id(PBD::ID id)
{
	if (_insert_id == "0") {
		_insert_id = id;
	} else if (_insert_id != id) {
		lilv_state_free(_impl->state);
		_impl->state = NULL;
		_insert_id   = id;
	}
}

void
LV2Plugin::set_state_dir (const std::string& d)
{
	_plugin_state_dir = d;
}

int
LV2Plugin::set_state(const XMLNode& node, int version)
{
	XMLNodeList          nodes;
	XMLNodeConstIterator iter;
	XMLNode*             child;
	LocaleGuard          lg;

	if (node.name() != state_node_name()) {
		error << _("Bad node sent to LV2Plugin::set_state") << endmsg;
		return -1;
	}

#ifndef NO_PLUGIN_STATE

	if (version < 3000) {
		nodes = node.children("port");
	} else {
		nodes = node.children("Port");
	}

	for (iter = nodes.begin(); iter != nodes.end(); ++iter) {

		child = *iter;

		std::string sym;
		if (!child->get_property("symbol", sym)) {
			warning << _("LV2: port has no symbol, ignored") << endmsg;
			continue;
		}

		map<string, uint32_t>::iterator i = _port_indices.find(sym);

		uint32_t port_id;

		if (i != _port_indices.end()) {
			port_id = i->second;
		} else {
			warning << _("LV2: port has unknown index, ignored") << endmsg;
			continue;
		}

		float val;
		if (!child->get_property("value", val)) {
			warning << _("LV2: port has no value, ignored") << endmsg;
			continue;
		}

		set_parameter(port_id, val);
	}

	std::string template_dir;
	if (node.get_property("template-dir", template_dir)) {
		set_state_dir (template_dir);
	}

	_state_version = 0;
	std::string state_dir;
	if (node.get_property("state-dir", state_dir) != 0) {
		if (sscanf(state_dir.c_str(), "state%u", &_state_version) != 1) {
			error << string_compose(
				"LV2: failed to parse state version from \"%1\"",
				state_dir) << endmsg;
		}

		std::string state_file = Glib::build_filename(
			plugin_dir(),
			Glib::build_filename(state_dir, "state.ttl"));

		LilvState* state = lilv_state_new_from_file(
			_world.world, _uri_map.urid_map(), NULL, state_file.c_str());

		lilv_state_restore(state, _impl->instance, NULL, NULL, 0, NULL);
		lilv_state_free(_impl->state);
		_impl->state = state;
	}

	if (!_plugin_state_dir.empty ()) {
		// force save with session, next time (increment counter)
		lilv_state_free (_impl->state);
		_impl->state = NULL;
		set_state_dir ("");
	}

	latency_compute_run();
#endif

	return Plugin::set_state(node, version);
}

int
LV2Plugin::get_parameter_descriptor(uint32_t which, ParameterDescriptor& desc) const
{
	const LilvPort* port = lilv_plugin_get_port_by_index(_impl->plugin, which);
	if (!port) {
		error << string_compose("LV2: get descriptor of non-existent port %1", which)
		      << endmsg;
		return 1;
	}

	LilvNodes* portunits;
	LilvNode *def, *min, *max;
	lilv_port_get_range(_impl->plugin, port, &def, &min, &max);
	portunits = lilv_port_get_value(_impl->plugin, port, _world.units_unit);

	LilvNode* steps   = lilv_port_get(_impl->plugin, port, _world.ext_rangeSteps);

	// TODO: Once we can rely on lilv 0.18.0 being present,
	// load_parameter_descriptor() can be used for ports as well
	desc.integer_step = lilv_port_has_property(_impl->plugin, port, _world.lv2_integer);
	desc.toggled      = lilv_port_has_property(_impl->plugin, port, _world.lv2_toggled);
	desc.logarithmic  = lilv_port_has_property(_impl->plugin, port, _world.ext_logarithmic);
	desc.sr_dependent = lilv_port_has_property(_impl->plugin, port, _world.lv2_sampleRate);
	desc.label        = lilv_node_as_string(lilv_port_get_name(_impl->plugin, port));
	desc.normal       = def ? lilv_node_as_float(def) : 0.0f;
	desc.lower        = min ? lilv_node_as_float(min) : 0.0f;
	desc.upper        = max ? lilv_node_as_float(max) : 1.0f;
	load_parameter_descriptor_units(_world.world, desc, portunits);

	if (desc.sr_dependent) {
		desc.lower *= _session.frame_rate ();
		desc.upper *= _session.frame_rate ();
	}

	desc.enumeration = lilv_port_has_property(_impl->plugin, port, _world.lv2_enumeration);
	desc.scale_points = get_scale_points(which);

	if (steps) {
		desc.rangesteps = lilv_node_as_float (steps);
	}

	desc.update_steps();

	lilv_node_free(def);
	lilv_node_free(min);
	lilv_node_free(max);
	lilv_node_free(steps);
	lilv_nodes_free(portunits);

	return 0;
}

Plugin::IOPortDescription
LV2Plugin::describe_io_port (ARDOUR::DataType dt, bool input, uint32_t id) const
{
	PortFlags match = 0;
	switch (dt) {
		case DataType::AUDIO:
			match = PORT_AUDIO;
			break;
		case DataType::MIDI:
			match = PORT_SEQUENCE | PORT_MIDI; // ignore old PORT_EVENT
			break;
		default:
			return Plugin::IOPortDescription ("?");
			break;
	}
	if (input) {
		match |= PORT_INPUT;
	} else {
		match |= PORT_OUTPUT;
	}

	uint32_t p = 0;
	uint32_t idx = UINT32_MAX;

	uint32_t const num_ports = parameter_count();
	for (uint32_t port_index = 0; port_index < num_ports; ++port_index) {
		PortFlags flags = _port_flags[port_index];
		if ((flags & match) == match) {
			if (p == id) {
				idx = port_index;
			}
			++p;
		}
	}
	if (idx == UINT32_MAX) {
		return Plugin::IOPortDescription ("?");
	}

	const LilvPort* pport = lilv_plugin_get_port_by_index (_impl->plugin, idx);

	LilvNode* name = lilv_port_get_name(_impl->plugin, pport);
	Plugin::IOPortDescription iod (lilv_node_as_string (name));
	lilv_node_free(name);

	/* get the port's pg:group */
	LilvNodes* groups = lilv_port_get_value (_impl->plugin, pport, _world.groups_group);
	if (lilv_nodes_size (groups) > 0) {
		const LilvNode* group = lilv_nodes_get_first (groups);
		LilvNodes* grouplabel = lilv_world_find_nodes (_world.world, group, _world.rdfs_label, NULL);

		/* get the name of the port-group */
		if (lilv_nodes_size (grouplabel) > 0) {
			const LilvNode* grpname = lilv_nodes_get_first (grouplabel);
			iod.group_name = lilv_node_as_string (grpname);
		}
		lilv_nodes_free (grouplabel);

		/* get all port designations.
		 * we're interested in e.g. lv2:designation pg:right */
		LilvNodes* designations = lilv_port_get_value (_impl->plugin, pport, _world.lv2_designation);
		if (lilv_nodes_size (designations) > 0) {
			/* get all pg:elements of the pg:group */
			LilvNodes* group_childs = lilv_world_find_nodes (_world.world, group, _world.groups_element, NULL);
			if (lilv_nodes_size (group_childs) > 0) {
				/* iterate over all port designations .. */
				LILV_FOREACH (nodes, i, designations) {
					const LilvNode* designation = lilv_nodes_get (designations, i);
					/* match the lv2:designation's element against the port-group's element */
					LILV_FOREACH (nodes, j, group_childs) {
						const LilvNode* group_element = lilv_nodes_get (group_childs, j);
						LilvNodes* elem = lilv_world_find_nodes (_world.world, group_element, _world.lv2_designation, designation);
						/* found it. Now look up the index (channel-number) of the pg:Element */
						if (lilv_nodes_size (elem) > 0) {
							LilvNodes* idx = lilv_world_find_nodes (_world.world, lilv_nodes_get_first (elem), _world.lv2_index, NULL);
							if (lilv_node_is_int (lilv_nodes_get_first (idx))) {
								iod.group_channel = lilv_node_as_int(lilv_nodes_get_first (idx));
							}
						}
					}
				}
			}
		}
		lilv_nodes_free (groups);
		lilv_nodes_free (designations);
	}

	if (lilv_port_has_property(_impl->plugin, pport, _world.lv2_isSideChain)) {
		iod.is_sidechain = true;
	}
	return iod;
}

string
LV2Plugin::describe_parameter(Evoral::Parameter which)
{
	if (( which.type() == PluginAutomation) && ( which.id() < parameter_count()) ) {

		if (lilv_port_has_property(_impl->plugin,
					lilv_plugin_get_port_by_index(_impl->plugin, which.id()), _world.ext_notOnGUI)) {
			return X_("hidden");
		}

		if (lilv_port_has_property(_impl->plugin,
					lilv_plugin_get_port_by_index(_impl->plugin, which.id()), _world.lv2_freewheeling)) {
			return X_("hidden");
		}

		if (lilv_port_has_property(_impl->plugin,
					lilv_plugin_get_port_by_index(_impl->plugin, which.id()), _world.lv2_reportsLatency)) {
			return X_("latency");
		}

		LilvNode* name = lilv_port_get_name(_impl->plugin,
		                                    lilv_plugin_get_port_by_index(_impl->plugin, which.id()));
		string ret(lilv_node_as_string(name));
		lilv_node_free(name);
		return ret;
	} else {
		return "??";
	}
}

framecnt_t
LV2Plugin::max_latency () const
{
	return _max_latency;
}

framecnt_t
LV2Plugin::signal_latency() const
{
	if (_latency_control_port) {
		return (framecnt_t)floor(*_latency_control_port);
	} else {
		return 0;
	}
}

set<Evoral::Parameter>
LV2Plugin::automatable() const
{
	set<Evoral::Parameter> ret;

	for (uint32_t i = 0; i < parameter_count(); ++i) {
		if (parameter_is_input(i) && parameter_is_control(i) && !(_port_flags[i] & PORT_NOAUTO)) {
			ret.insert(ret.end(), Evoral::Parameter(PluginAutomation, 0, i));
		}
	}

	for (PropertyDescriptors::const_iterator p = _property_descriptors.begin();
	     p != _property_descriptors.end();
	     ++p) {
		ret.insert(ret.end(), Evoral::Parameter(PluginPropertyAutomation, 0, p->first));
	}
	return ret;
}

void
LV2Plugin::set_automation_control (uint32_t i, boost::shared_ptr<AutomationControl> c)
{
	if ((_port_flags[i] & (PORT_CTRLED | PORT_CTRLER))) {
		DEBUG_TRACE(DEBUG::LV2Automate, string_compose ("Ctrl Port %1\n", i));
		_ctrl_map [i] = AutomationCtrlPtr (new AutomationCtrl(c));
	}
}

LV2Plugin::AutomationCtrlPtr
LV2Plugin::get_automation_control (uint32_t i)
{
	if (_ctrl_map.find (i) == _ctrl_map.end()) {
		return AutomationCtrlPtr ();
	}
	return _ctrl_map[i];
}

void
LV2Plugin::activate()
{
	DEBUG_TRACE(DEBUG::LV2, string_compose("%1 activate\n", name()));

	if (!_was_activated) {
		lilv_instance_activate(_impl->instance);
		_was_activated = true;
	}
}

void
LV2Plugin::deactivate()
{
	DEBUG_TRACE(DEBUG::LV2, string_compose("%1 deactivate\n", name()));

	if (_was_activated) {
		lilv_instance_deactivate(_impl->instance);
		_was_activated = false;
	}
}

void
LV2Plugin::cleanup()
{
	DEBUG_TRACE(DEBUG::LV2, string_compose("%1 cleanup\n", name()));

	deactivate();
	lilv_instance_free(_impl->instance);
	_impl->instance = NULL;
}

void
LV2Plugin::allocate_atom_event_buffers()
{
	/* reserve local scratch buffers for ATOM event-queues */
	const LilvPlugin* p = _impl->plugin;

	/* count non-MIDI atom event-ports
	 * TODO: nicely ask drobilla to make a lilv_ call for that
	 */
	int count_atom_out = 0;
	int count_atom_in = 0;
	int minimumSize = 32768; // TODO use a per-port minimum-size
	for (uint32_t i = 0; i < lilv_plugin_get_num_ports(p); ++i) {
		const LilvPort* port  = lilv_plugin_get_port_by_index(p, i);
		if (lilv_port_is_a(p, port, _world.atom_AtomPort)) {
			LilvNodes* buffer_types = lilv_port_get_value(
				p, port, _world.atom_bufferType);
			LilvNodes* atom_supports = lilv_port_get_value(
				p, port, _world.atom_supports);

			if (lilv_nodes_contains(buffer_types, _world.atom_Sequence)) {
				if (lilv_port_is_a(p, port, _world.lv2_InputPort)) {
					count_atom_in++;
				}
				if (lilv_port_is_a(p, port, _world.lv2_OutputPort)) {
					count_atom_out++;
				}
				LilvNodes* min_size_v = lilv_port_get_value(_impl->plugin, port, _world.rsz_minimumSize);
				LilvNode* min_size = min_size_v ? lilv_nodes_get_first(min_size_v) : NULL;
				if (min_size && lilv_node_is_int(min_size)) {
					minimumSize = std::max(minimumSize, lilv_node_as_int(min_size));
				}
				lilv_nodes_free(min_size_v);
			}
			lilv_nodes_free(buffer_types);
			lilv_nodes_free(atom_supports);
		}
	}

	DEBUG_TRACE(DEBUG::LV2, string_compose("%1 need buffers for %2 atom-in and %3 atom-out event-ports\n",
				name(), count_atom_in, count_atom_out));

	const int total_atom_buffers = (count_atom_in + count_atom_out);
	if (_atom_ev_buffers || total_atom_buffers == 0) {
		return;
	}

	DEBUG_TRACE(DEBUG::LV2, string_compose("allocate %1 atom_ev_buffers of %2 bytes\n", total_atom_buffers, minimumSize));
	_atom_ev_buffers = (LV2_Evbuf**) malloc((total_atom_buffers + 1) * sizeof(LV2_Evbuf*));
	for (int i = 0; i < total_atom_buffers; ++i ) {
		_atom_ev_buffers[i] = lv2_evbuf_new(minimumSize, LV2_EVBUF_ATOM,
				_uri_map.urids.atom_Chunk, _uri_map.urids.atom_Sequence);
	}
	_atom_ev_buffers[total_atom_buffers] = 0;
	return;
}

/** Write an ardour position/time/tempo/meter as an LV2 event.
 * @return true on success.
 */
static bool
write_position(LV2_Atom_Forge*     forge,
               LV2_Evbuf*          buf,
               const TempoMetric&  t,
               Timecode::BBT_Time& bbt,
               double              speed,
               double              bpm,
               framepos_t          position,
               framecnt_t          offset)
{
	const URIMap::URIDs& urids = URIMap::instance().urids;

	uint8_t pos_buf[256];
	lv2_atom_forge_set_buffer(forge, pos_buf, sizeof(pos_buf));
	LV2_Atom_Forge_Frame frame;
#ifdef HAVE_LV2_1_10_0
	lv2_atom_forge_object(forge, &frame, 0, urids.time_Position);
	lv2_atom_forge_key(forge, urids.time_frame);
	lv2_atom_forge_long(forge, position);
	lv2_atom_forge_key(forge, urids.time_speed);
	lv2_atom_forge_float(forge, speed);
	lv2_atom_forge_key(forge, urids.time_barBeat);
	lv2_atom_forge_float(forge, bbt.beats - 1 +
	                     (bbt.ticks / Timecode::BBT_Time::ticks_per_beat));
	lv2_atom_forge_key(forge, urids.time_bar);
	lv2_atom_forge_long(forge, bbt.bars - 1);
	lv2_atom_forge_key(forge, urids.time_beatUnit);
	lv2_atom_forge_int(forge, t.meter().note_divisor());
	lv2_atom_forge_key(forge, urids.time_beatsPerBar);
	lv2_atom_forge_float(forge, t.meter().divisions_per_bar());
	lv2_atom_forge_key(forge, urids.time_beatsPerMinute);
	lv2_atom_forge_float(forge, bpm);
#else
	lv2_atom_forge_blank(forge, &frame, 1, urids.time_Position);
	lv2_atom_forge_property_head(forge, urids.time_frame, 0);
	lv2_atom_forge_long(forge, position);
	lv2_atom_forge_property_head(forge, urids.time_speed, 0);
	lv2_atom_forge_float(forge, speed);
	lv2_atom_forge_property_head(forge, urids.time_barBeat, 0);
	lv2_atom_forge_float(forge, bbt.beats - 1 +
	                     (bbt.ticks / Timecode::BBT_Time::ticks_per_beat));
	lv2_atom_forge_property_head(forge, urids.time_bar, 0);
	lv2_atom_forge_long(forge, bbt.bars - 1);
	lv2_atom_forge_property_head(forge, urids.time_beatUnit, 0);
	lv2_atom_forge_int(forge, t.meter().note_divisor());
	lv2_atom_forge_property_head(forge, urids.time_beatsPerBar, 0);
	lv2_atom_forge_float(forge, t.meter().divisions_per_bar());
	lv2_atom_forge_property_head(forge, urids.time_beatsPerMinute, 0);
	lv2_atom_forge_float(forge, bpm);
#endif

	LV2_Evbuf_Iterator    end  = lv2_evbuf_end(buf);
	const LV2_Atom* const atom = (const LV2_Atom*)pos_buf;
	return lv2_evbuf_write(&end, offset, 0, atom->type, atom->size,
	                       (const uint8_t*)(atom + 1));
}

int
LV2Plugin::connect_and_run(BufferSet& bufs,
		framepos_t start, framepos_t end, double speed,
		ChanMapping in_map, ChanMapping out_map,
		pframes_t nframes, framecnt_t offset)
{
	DEBUG_TRACE(DEBUG::LV2, string_compose("%1 run %2 offset %3\n", name(), nframes, offset));
	Plugin::connect_and_run(bufs, start, end, speed, in_map, out_map, nframes, offset);

	cycles_t then = get_cycles();

	TempoMap&               tmap     = _session.tempo_map();
	Metrics::const_iterator metric_i = tmap.metrics_end();
	TempoMetric             tmetric  = tmap.metric_at(start, &metric_i);

	if (_freewheel_control_port) {
		*_freewheel_control_port = _session.engine().freewheeling() ? 1.f : 0.f;
	}

	if (_bpm_control_port) {
		*_bpm_control_port = tmap.tempo_at_frame (start).note_types_per_minute();
	}

#ifdef LV2_EXTENDED
	if (_can_write_automation && start != _next_cycle_start) {
		// add guard-points after locating
		for (AutomationCtrlMap::iterator i = _ctrl_map.begin(); i != _ctrl_map.end(); ++i) {
			i->second->guard = true;
		}
	}
#endif

	ChanCount bufs_count;
	bufs_count.set(DataType::AUDIO, 1);
	bufs_count.set(DataType::MIDI, 1);
	BufferSet& silent_bufs  = _session.get_silent_buffers(bufs_count);
	BufferSet& scratch_bufs = _session.get_scratch_buffers(bufs_count);
	uint32_t const num_ports = parameter_count();
	uint32_t const nil_index = std::numeric_limits<uint32_t>::max();

	uint32_t audio_in_index  = 0;
	uint32_t audio_out_index = 0;
	uint32_t midi_in_index   = 0;
	uint32_t midi_out_index  = 0;
	uint32_t atom_port_index = 0;
	for (uint32_t port_index = 0; port_index < num_ports; ++port_index) {
		void*     buf   = NULL;
		uint32_t  index = nil_index;
		PortFlags flags = _port_flags[port_index];
		bool      valid = false;
		if (flags & PORT_AUDIO) {
			if (flags & PORT_INPUT) {
				index = in_map.get(DataType::AUDIO, audio_in_index++, &valid);
				buf = (valid)
					? bufs.get_audio(index).data(offset)
					: silent_bufs.get_audio(0).data(offset);
			} else {
				index = out_map.get(DataType::AUDIO, audio_out_index++, &valid);
				buf = (valid)
					? bufs.get_audio(index).data(offset)
					: scratch_bufs.get_audio(0).data(offset);
			}
		} else if (flags & (PORT_EVENT|PORT_SEQUENCE)) {
			/* FIXME: The checks here for bufs.count().n_midi() > index shouldn't
			   be necessary, but the mapping is illegal in some cases.  Ideally
			   that should be fixed, but this is easier...
			*/
			if (flags & PORT_MIDI) {
				if (flags & PORT_INPUT) {
					index = in_map.get(DataType::MIDI, midi_in_index++, &valid);
				} else {
					index = out_map.get(DataType::MIDI, midi_out_index++, &valid);
				}
				if (valid && bufs.count().n_midi() > index) {
					/* Note, ensure_lv2_bufsize() is not RT safe!
					 * However free()/alloc() is only called if a
					 * plugin requires a rsz:minimumSize buffersize
					 * and the existing buffer if smaller.
					 */
					bufs.ensure_lv2_bufsize((flags & PORT_INPUT), index, _port_minimumSize[port_index]);
					_ev_buffers[port_index] = bufs.get_lv2_midi(
						(flags & PORT_INPUT), index, (flags & PORT_EVENT));
				}
			} else if ((flags & PORT_POSITION) && (flags & PORT_INPUT)) {
				lv2_evbuf_reset(_atom_ev_buffers[atom_port_index], true);
				_ev_buffers[port_index] = _atom_ev_buffers[atom_port_index++];
				valid                   = true;
			}

			if (valid && (flags & PORT_INPUT)) {
				if ((flags & PORT_POSITION)) {
					Timecode::BBT_Time bbt (tmap.bbt_at_frame (start));
					double bpm = tmap.tempo_at_frame (start).note_types_per_minute();
					double beatpos = (bbt.bars - 1) * tmetric.meter().divisions_per_bar()
					               + (bbt.beats - 1)
					               + (bbt.ticks / Timecode::BBT_Time::ticks_per_beat);
					beatpos *= tmetric.meter().note_divisor() / 4.0;
					if (start != _next_cycle_start ||
							speed != _next_cycle_speed ||
							rint (1000 * beatpos) != rint(1000 * _next_cycle_beat) ||
							bpm != _current_bpm) {
						// Transport or Tempo has changed, write position at cycle start
						write_position(&_impl->forge, _ev_buffers[port_index],
								tmetric, bbt, speed, bpm, start, 0);
					}
				}

				// Get MIDI iterator range (empty range if no MIDI)
				MidiBuffer::iterator m = (index != nil_index)
					? bufs.get_midi(index).begin()
					: silent_bufs.get_midi(0).end();
				MidiBuffer::iterator m_end = (index != nil_index)
					? bufs.get_midi(index).end()
					: m;

				// Now merge MIDI and any transport events into the buffer
				const uint32_t     type = _uri_map.urids.midi_MidiEvent;
				const framepos_t   tend = end;
				++metric_i;
				while (m != m_end || (metric_i != tmap.metrics_end() &&
				                      (*metric_i)->frame() < tend)) {
					MetricSection* metric = (metric_i != tmap.metrics_end())
						? *metric_i : NULL;
					if (m != m_end && (!metric || metric->frame() > (*m).time())) {
						const Evoral::Event<framepos_t> ev(*m, false);
						if (ev.time() < nframes) {
							LV2_Evbuf_Iterator eend = lv2_evbuf_end(_ev_buffers[port_index]);
							lv2_evbuf_write(&eend, ev.time(), 0, type, ev.size(), ev.buffer());
						}
						++m;
					} else {
						tmetric.set_metric(metric);
						Timecode::BBT_Time bbt;
						bbt = tmap.bbt_at_frame (metric->frame());
						double bpm = tmap.tempo_at_frame (start/*XXX*/).note_types_per_minute();
						write_position(&_impl->forge, _ev_buffers[port_index],
						               tmetric, bbt, speed, bpm,
						               metric->frame(),
						               metric->frame() - start);
						++metric_i;
					}
				}
			} else if (!valid) {
				// Nothing we understand or care about, connect to scratch
				// see note for midi-buffer size above
				scratch_bufs.ensure_lv2_bufsize((flags & PORT_INPUT),
						0, _port_minimumSize[port_index]);
				_ev_buffers[port_index] = scratch_bufs.get_lv2_midi(
					(flags & PORT_INPUT), 0, (flags & PORT_EVENT));
			}

			buf = lv2_evbuf_get_buffer(_ev_buffers[port_index]);
		} else {
			continue;  // Control port, leave buffer alone
		}
		lilv_instance_connect_port(_impl->instance, port_index, buf);
	}

	// Read messages from UI and push into appropriate buffers
	if (_from_ui) {
		uint32_t read_space = _from_ui->read_space();
		while (read_space > sizeof(UIMessage)) {
			UIMessage msg;
			if (_from_ui->read((uint8_t*)&msg, sizeof(msg)) != sizeof(msg)) {
				error << "Error reading from UI=>Plugin RingBuffer" << endmsg;
				break;
			}
			vector<uint8_t> body(msg.size);
			if (_from_ui->read(&body[0], msg.size) != msg.size) {
				error << "Error reading from UI=>Plugin RingBuffer" << endmsg;
				break;
			}
			if (msg.protocol == URIMap::instance().urids.atom_eventTransfer) {
				LV2_Evbuf*            buf  = _ev_buffers[msg.index];
				LV2_Evbuf_Iterator    i    = lv2_evbuf_end(buf);
				const LV2_Atom* const atom = (const LV2_Atom*)&body[0];
				if (!lv2_evbuf_write(&i, nframes - 1, 0, atom->type, atom->size,
				                (const uint8_t*)(atom + 1))) {
					error << "Failed to write data to LV2 event buffer\n";
				}
			} else {
				error << "Received unknown message type from UI" << endmsg;
			}
			read_space -= sizeof(UIMessage) + msg.size;
		}
	}

	run(nframes);

	midi_out_index = 0;
	for (uint32_t port_index = 0; port_index < num_ports; ++port_index) {
		PortFlags flags = _port_flags[port_index];
		bool      valid = false;

		/* TODO ask drobilla about comment
		 * "Make Ardour event buffers generic so plugins can communicate"
		 * in libs/ardour/buffer_set.cc:310
		 *
		 * ideally the user could choose which of the following two modes
		 * to use (e.g. instrument/effect chains  MIDI OUT vs MIDI TRHU).
		 *
		 * This implementation follows the discussion on IRC Mar 16 2013 16:47 UTC
		 * 16:51 < drobilla> rgareus: [..] i.e always replace with MIDI output [of LV2 plugin] if it's there
		 * 16:52 < drobilla> rgareus: That would probably be good enough [..] to make users not complain
		 *                            for quite a while at least ;)
		 */
		// copy output of LV2 plugin's MIDI port to Ardour MIDI buffers -- MIDI OUT
		if ((flags & PORT_OUTPUT) && (flags & (PORT_EVENT|PORT_SEQUENCE|PORT_MIDI))) {
			const uint32_t buf_index = out_map.get(
				DataType::MIDI, midi_out_index++, &valid);
			if (valid) {
				bufs.forward_lv2_midi(_ev_buffers[port_index], buf_index);
			}
		}
		// Flush MIDI (write back to Ardour MIDI buffers) -- MIDI THRU
		else if ((flags & PORT_OUTPUT) && (flags & (PORT_EVENT|PORT_SEQUENCE))) {
			const uint32_t buf_index = out_map.get(
				DataType::MIDI, midi_out_index++, &valid);
			if (valid) {
				bufs.flush_lv2_midi(true, buf_index);
			}
		}

		// Write messages to UI
		if ((_to_ui || _can_write_automation || _patch_port_out_index != (uint32_t)-1) &&
		    (flags & PORT_OUTPUT) && (flags & (PORT_EVENT|PORT_SEQUENCE))) {
			LV2_Evbuf* buf = _ev_buffers[port_index];
			for (LV2_Evbuf_Iterator i = lv2_evbuf_begin(buf);
			     lv2_evbuf_is_valid(i);
			     i = lv2_evbuf_next(i)) {
				uint32_t frames, subframes, type, size;
				uint8_t* data;
				lv2_evbuf_get(i, &frames, &subframes, &type, &size, &data);

#ifdef LV2_EXTENDED
				// Intercept Automation Write Events
				if ((flags & PORT_AUTOCTRL)) {
					LV2_Atom* atom = (LV2_Atom*)(data - sizeof(LV2_Atom));
					if (atom->type == _uri_map.urids.atom_Blank ||
							atom->type == _uri_map.urids.atom_Object) {
						LV2_Atom_Object* obj = (LV2_Atom_Object*)atom;
						if (obj->body.otype == _uri_map.urids.auto_event) {
							// only if transport_rolling ??
							const LV2_Atom* parameter = NULL;
							const LV2_Atom* value    = NULL;
							lv2_atom_object_get(obj,
							                    _uri_map.urids.auto_parameter, &parameter,
							                    _uri_map.urids.auto_value,     &value,
							                    0);
							if (parameter && value) {
								const uint32_t p = ((const LV2_Atom_Int*)parameter)->body;
								const float v = ((const LV2_Atom_Float*)value)->body;
								// -> add automation event..
								DEBUG_TRACE(DEBUG::LV2Automate,
										string_compose ("Event p: %1 t: %2 v: %3\n", p, frames, v));
								AutomationCtrlPtr c = get_automation_control (p);
								if (c &&
								     (c->ac->automation_state() == Touch || c->ac->automation_state() == Write)
								   ) {
									framepos_t when = std::max ((framepos_t) 0, start + frames - _current_latency);
									assert (start + frames - _current_latency >= 0);
									if (c->guard) {
										c->guard = false;
										c->ac->list()->add (when, v, true, true);
									} else {
										c->ac->set_double (v, when, true);
									}
								}
							}
						}
						else if (obj->body.otype == _uri_map.urids.auto_setup) {
							// TODO optional arguments, for now we assume the plugin
							// writes automation for its own inputs
							// -> put them in "touch" mode (preferably "exclusive plugin touch(TM)"
							for (AutomationCtrlMap::iterator i = _ctrl_map.begin(); i != _ctrl_map.end(); ++i) {
								if (_port_flags[i->first] & PORT_CTRLED) {
									DEBUG_TRACE(DEBUG::LV2Automate,
										string_compose ("Setup p: %1\n", i->first));
									i->second->ac->set_automation_state (Touch);
								}
							}
						}
						else if (obj->body.otype == _uri_map.urids.auto_finalize) {
							// set [touched] parameters to "play" ??
							// allow plugin to change its mode (from analyze to apply)
							const LV2_Atom* parameter = NULL;
							const LV2_Atom* value    = NULL;
							lv2_atom_object_get(obj,
							                    _uri_map.urids.auto_parameter, &parameter,
							                    _uri_map.urids.auto_value,     &value,
							                    0);
							if (parameter && value) {
								const uint32_t p = ((const LV2_Atom_Int*)parameter)->body;
								const float v = ((const LV2_Atom_Float*)value)->body;
								AutomationCtrlPtr c = get_automation_control (p);
								DEBUG_TRACE(DEBUG::LV2Automate,
										string_compose ("Finalize p: %1 v: %2\n", p, v));
								if (c && _port_flags[p] & PORT_CTRLER) {
									c->ac->set_value(v, Controllable::NoGroup);
								}
							} else {
								DEBUG_TRACE(DEBUG::LV2Automate, "Finalize\n");
							}
							for (AutomationCtrlMap::iterator i = _ctrl_map.begin(); i != _ctrl_map.end(); ++i) {
								// guard will be false if an event was written
								if ((_port_flags[i->first] & PORT_CTRLED) && !i->second->guard) {
									DEBUG_TRACE(DEBUG::LV2Automate,
										string_compose ("Thin p: %1\n", i->first));
									i->second->ac->alist ()->thin (20);
								}
							}
						}
						else if (obj->body.otype == _uri_map.urids.auto_start) {
							const LV2_Atom* parameter = NULL;
							lv2_atom_object_get(obj,
							                    _uri_map.urids.auto_parameter, &parameter,
							                    0);
							if (parameter) {
								const uint32_t p = ((const LV2_Atom_Int*)parameter)->body;
								AutomationCtrlPtr c = get_automation_control (p);
								DEBUG_TRACE(DEBUG::LV2Automate, string_compose ("Start Touch p: %1\n", p));
								if (c) {
									c->ac->start_touch (std::max ((framepos_t)0, start - _current_latency));
									c->guard = true;
								}
							}
						}
						else if (obj->body.otype == _uri_map.urids.auto_end) {
							const LV2_Atom* parameter = NULL;
							lv2_atom_object_get(obj,
							                    _uri_map.urids.auto_parameter, &parameter,
							                    0);
							if (parameter) {
								const uint32_t p = ((const LV2_Atom_Int*)parameter)->body;
								AutomationCtrlPtr c = get_automation_control (p);
								DEBUG_TRACE(DEBUG::LV2Automate, string_compose ("End Touch p: %1\n", p));
								if (c) {
									c->ac->stop_touch (true, std::max ((framepos_t)0, start - _current_latency));
								}
							}
						}
					}
				}
#endif
				// Intercept state dirty message
				if (_has_state_interface /* && (flags & PORT_DIRTYMSG)*/) {
					LV2_Atom* atom = (LV2_Atom*)(data - sizeof(LV2_Atom));
					if (atom->type == _uri_map.urids.atom_Blank ||
					    atom->type == _uri_map.urids.atom_Object) {
						LV2_Atom_Object* obj = (LV2_Atom_Object*)atom;
						if (obj->body.otype == _uri_map.urids.state_StateChanged) {
							_session.set_dirty ();
						}
					}
				}

				// Intercept patch change messages to emit PropertyChanged signal
				if ((flags & PORT_PATCHMSG)) {
					LV2_Atom* atom = (LV2_Atom*)(data - sizeof(LV2_Atom));
					if (atom->type == _uri_map.urids.atom_Blank ||
					    atom->type == _uri_map.urids.atom_Object) {
						LV2_Atom_Object* obj = (LV2_Atom_Object*)atom;
						if (obj->body.otype == _uri_map.urids.patch_Set) {
							const LV2_Atom* property = NULL;
							const LV2_Atom* value    = NULL;
							lv2_atom_object_get(obj,
							                    _uri_map.urids.patch_property, &property,
							                    _uri_map.urids.patch_value,    &value,
							                    0);

							if (property && value &&
							    property->type == _uri_map.urids.atom_URID &&
							    value->type    == _uri_map.urids.atom_Path) {
								const uint32_t prop_id = ((const LV2_Atom_URID*)property)->body;
								const char*    path    = (const char*)LV2_ATOM_BODY_CONST(value);

								// Emit PropertyChanged signal for UI
								// TODO: This should emit the control's Changed signal
								PropertyChanged(prop_id, Variant(Variant::PATH, path));
							} else {
								std::cerr << "warning: patch:Set for unknown property" << std::endl;
							}
						}
					}
				}

				if (!_to_ui) continue;
				write_to_ui(port_index, URIMap::instance().urids.atom_eventTransfer,
				            size + sizeof(LV2_Atom),
				            data - sizeof(LV2_Atom));
			}
		}
	}

	cycles_t now = get_cycles();
	set_cycles((uint32_t)(now - then));

	// Update expected transport information for next cycle so we can detect changes
	_next_cycle_speed = speed;
	_next_cycle_start = end;

	{
		/* keep track of lv2:timePosition like plugins can do.
		 * Note: for no-midi plugins, we only ever send information at cycle-start,
		 * so it needs to be realative to that.
		 */
		TempoMetric t = tmap.metric_at(start);
		_current_bpm = tmap.tempo_at_frame (start).note_types_per_minute();
		Timecode::BBT_Time bbt (tmap.bbt_at_frame (start));
		double beatpos = (bbt.bars - 1) * t.meter().divisions_per_bar()
		               + (bbt.beats - 1)
		               + (bbt.ticks / Timecode::BBT_Time::ticks_per_beat);
		beatpos *= tmetric.meter().note_divisor() / 4.0;
		_next_cycle_beat = beatpos + nframes * speed * _current_bpm / (60.f * _session.frame_rate());
	}

	if (_latency_control_port) {
		framecnt_t new_latency = signal_latency ();
		_current_latency = new_latency;
	}
	return 0;
}

bool
LV2Plugin::parameter_is_control(uint32_t param) const
{
	assert(param < _port_flags.size());
	return _port_flags[param] & PORT_CONTROL;
}

bool
LV2Plugin::parameter_is_audio(uint32_t param) const
{
	assert(param < _port_flags.size());
	return _port_flags[param] & PORT_AUDIO;
}

bool
LV2Plugin::parameter_is_event(uint32_t param) const
{
	assert(param < _port_flags.size());
	return _port_flags[param] & PORT_EVENT;
}

bool
LV2Plugin::parameter_is_output(uint32_t param) const
{
	assert(param < _port_flags.size());
	return _port_flags[param] & PORT_OUTPUT;
}

bool
LV2Plugin::parameter_is_input(uint32_t param) const
{
	assert(param < _port_flags.size());
	return _port_flags[param] & PORT_INPUT;
}

uint32_t
LV2Plugin::designated_bypass_port ()
{
	const LilvPort* port = NULL;
	LilvNode* designation = lilv_new_uri (_world.world, LV2_CORE_PREFIX "enabled");
	port = lilv_plugin_get_port_by_designation (
			_impl->plugin, _world.lv2_InputPort, designation);
	lilv_node_free(designation);
	if (port) {
		return lilv_port_get_index (_impl->plugin, port);
	}
#ifdef LV2_EXTENDED
	/* deprecated on 2016-Sep-18 in favor of lv2:enabled */
	designation = lilv_new_uri (_world.world, LV2_PROCESSING_URI__enable);
	port = lilv_plugin_get_port_by_designation (
			_impl->plugin, _world.lv2_InputPort, designation);
	lilv_node_free(designation);
	if (port) {
		return lilv_port_get_index (_impl->plugin, port);
	}
#endif
	return UINT32_MAX;
}

void
LV2Plugin::print_parameter(uint32_t param, char* buf, uint32_t len) const
{
	if (buf && len) {
		if (param < parameter_count()) {
			snprintf(buf, len, "%.3f", get_parameter(param));
		} else {
			strcat(buf, "0");
		}
	}
}

boost::shared_ptr<ScalePoints>
LV2Plugin::get_scale_points(uint32_t port_index) const
{
	const LilvPort*  port   = lilv_plugin_get_port_by_index(_impl->plugin, port_index);
	LilvScalePoints* points = lilv_port_get_scale_points(_impl->plugin, port);

	boost::shared_ptr<ScalePoints> ret;
	if (!points) {
		return ret;
	}

	ret = boost::shared_ptr<ScalePoints>(new ScalePoints());

	LILV_FOREACH(scale_points, i, points) {
		const LilvScalePoint* p     = lilv_scale_points_get(points, i);
		const LilvNode*       label = lilv_scale_point_get_label(p);
		const LilvNode*       value = lilv_scale_point_get_value(p);
		if (label && (lilv_node_is_float(value) || lilv_node_is_int(value))) {
			ret->insert(make_pair(lilv_node_as_string(label),
			                      lilv_node_as_float(value)));
		}
	}

	lilv_scale_points_free(points);
	return ret;
}

void
LV2Plugin::run(pframes_t nframes, bool sync_work)
{
	uint32_t const N = parameter_count();
	for (uint32_t i = 0; i < N; ++i) {
		if (parameter_is_control(i) && parameter_is_input(i)) {
			_control_data[i] = _shadow_data[i];
		}
	}

	if (_worker) {
		// Execute work synchronously if we're freewheeling (export)
		_worker->set_synchronous(sync_work || session().engine().freewheeling());
	}

	// Run the plugin for this cycle
	lilv_instance_run(_impl->instance, nframes);

	// Emit any queued worker responses (calls a plugin callback)
	if (_state_worker) {
		_state_worker->emit_responses();
	}
	if (_worker) {
		_worker->emit_responses();
	}

	// Notify the plugin that a work run cycle is complete
	if (_impl->work_iface) {
		if (_impl->work_iface->end_run) {
			_impl->work_iface->end_run(_impl->instance->lv2_handle);
		}
	}
}

void
LV2Plugin::latency_compute_run()
{
	if (!_latency_control_port) {
		return;
	}

	// Run the plugin so that it can set its latency parameter

	bool was_activated = _was_activated;
	activate();

	uint32_t port_index = 0;
	uint32_t in_index   = 0;
	uint32_t out_index  = 0;

	// this is done in the main thread. non realtime.
	const framecnt_t bufsize = _engine.samples_per_cycle();
	float            *buffer = (float*) malloc(_engine.samples_per_cycle() * sizeof(float));

	memset(buffer, 0, sizeof(float) * bufsize);

	// FIXME: Ensure plugins can handle in-place processing

	port_index = 0;

	while (port_index < parameter_count()) {
		if (parameter_is_audio(port_index)) {
			if (parameter_is_input(port_index)) {
				lilv_instance_connect_port(_impl->instance, port_index, buffer);
				in_index++;
			} else if (parameter_is_output(port_index)) {
				lilv_instance_connect_port(_impl->instance, port_index, buffer);
				out_index++;
			}
		}
		port_index++;
	}

	run(bufsize, true);
	deactivate();
	if (was_activated) {
		activate();
	}
	free(buffer);
}

const LilvPort*
LV2Plugin::Impl::designated_input (const char* uri, void** bufptrs[], void** bufptr)
{
	const LilvPort* port = NULL;
	LilvNode* designation = lilv_new_uri(_world.world, uri);
	port = lilv_plugin_get_port_by_designation(
		plugin, _world.lv2_InputPort, designation);
	lilv_node_free(designation);
	if (port) {
		bufptrs[lilv_port_get_index(plugin, port)] = bufptr;
	}
	return port;
}

static bool lv2_filter (const string& str, void* /*arg*/)
{
	/* Not a dotfile, has a prefix before a period, suffix is "lv2" */

	return str[0] != '.' && (str.length() > 3 && str.find (".lv2") == (str.length() - 4));
}


LV2World::LV2World()
	: world(lilv_world_new())
	, _bundle_checked(false)
{
	atom_AtomPort      = lilv_new_uri(world, LV2_ATOM__AtomPort);
	atom_Chunk         = lilv_new_uri(world, LV2_ATOM__Chunk);
	atom_Sequence      = lilv_new_uri(world, LV2_ATOM__Sequence);
	atom_bufferType    = lilv_new_uri(world, LV2_ATOM__bufferType);
	atom_supports      = lilv_new_uri(world, LV2_ATOM__supports);
	atom_eventTransfer = lilv_new_uri(world, LV2_ATOM__eventTransfer);
	ev_EventPort       = lilv_new_uri(world, LILV_URI_EVENT_PORT);
	ext_logarithmic    = lilv_new_uri(world, LV2_PORT_PROPS__logarithmic);
	ext_notOnGUI       = lilv_new_uri(world, LV2_PORT_PROPS__notOnGUI);
	ext_expensive      = lilv_new_uri(world, LV2_PORT_PROPS__expensive);
	ext_causesArtifacts= lilv_new_uri(world, LV2_PORT_PROPS__causesArtifacts);
	ext_notAutomatic   = lilv_new_uri(world, LV2_PORT_PROPS__notAutomatic);
	ext_rangeSteps     = lilv_new_uri(world, LV2_PORT_PROPS__rangeSteps);
	groups_group       = lilv_new_uri(world, LV2_PORT_GROUPS__group);
	groups_element     = lilv_new_uri(world, LV2_PORT_GROUPS__element);
	lv2_AudioPort      = lilv_new_uri(world, LILV_URI_AUDIO_PORT);
	lv2_ControlPort    = lilv_new_uri(world, LILV_URI_CONTROL_PORT);
	lv2_InputPort      = lilv_new_uri(world, LILV_URI_INPUT_PORT);
	lv2_OutputPort     = lilv_new_uri(world, LILV_URI_OUTPUT_PORT);
	lv2_inPlaceBroken  = lilv_new_uri(world, LV2_CORE__inPlaceBroken);
	lv2_isSideChain    = lilv_new_uri(world, LV2_CORE_PREFIX "isSideChain");
	lv2_index          = lilv_new_uri(world, LV2_CORE__index);
	lv2_integer        = lilv_new_uri(world, LV2_CORE__integer);
	lv2_default        = lilv_new_uri(world, LV2_CORE__default);
	lv2_minimum        = lilv_new_uri(world, LV2_CORE__minimum);
	lv2_maximum        = lilv_new_uri(world, LV2_CORE__maximum);
	lv2_reportsLatency = lilv_new_uri(world, LV2_CORE__reportsLatency);
	lv2_sampleRate     = lilv_new_uri(world, LV2_CORE__sampleRate);
	lv2_toggled        = lilv_new_uri(world, LV2_CORE__toggled);
	lv2_designation    = lilv_new_uri(world, LV2_CORE__designation);
	lv2_enumeration    = lilv_new_uri(world, LV2_CORE__enumeration);
	lv2_freewheeling   = lilv_new_uri(world, LV2_CORE__freeWheeling);
	midi_MidiEvent     = lilv_new_uri(world, LILV_URI_MIDI_EVENT);
	rdfs_comment       = lilv_new_uri(world, LILV_NS_RDFS "comment");
	rdfs_label         = lilv_new_uri(world, LILV_NS_RDFS "label");
	rdfs_range         = lilv_new_uri(world, LILV_NS_RDFS "range");
	rsz_minimumSize    = lilv_new_uri(world, LV2_RESIZE_PORT__minimumSize);
	time_Position      = lilv_new_uri(world, LV2_TIME__Position);
	ui_GtkUI           = lilv_new_uri(world, LV2_UI__GtkUI);
	ui_external        = lilv_new_uri(world, "http://lv2plug.in/ns/extensions/ui#external");
	ui_externalkx      = lilv_new_uri(world, "http://kxstudio.sf.net/ns/lv2ext/external-ui#Widget");
	units_unit         = lilv_new_uri(world, LV2_UNITS__unit);
	units_render       = lilv_new_uri(world, LV2_UNITS__render);
	units_hz           = lilv_new_uri(world, LV2_UNITS__hz);
	units_midiNote     = lilv_new_uri(world, LV2_UNITS__midiNote);
	units_db           = lilv_new_uri(world, LV2_UNITS__db);
	patch_writable     = lilv_new_uri(world, LV2_PATCH__writable);
	patch_Message      = lilv_new_uri(world, LV2_PATCH__Message);
#ifdef LV2_EXTENDED
	lv2_noSampleAccurateCtrl    = lilv_new_uri(world, "http://ardour.org/lv2/ext#noSampleAccurateControls"); // deprecated 2016-09-18
	auto_can_write_automatation = lilv_new_uri(world, LV2_AUTOMATE_URI__can_write);
	auto_automation_control     = lilv_new_uri(world, LV2_AUTOMATE_URI__control);
	auto_automation_controlled  = lilv_new_uri(world, LV2_AUTOMATE_URI__controlled);
	auto_automation_controller  = lilv_new_uri(world, LV2_AUTOMATE_URI__controller);
#endif
#ifdef HAVE_LV2_1_2_0
	bufz_powerOf2BlockLength = lilv_new_uri(world, LV2_BUF_SIZE__powerOf2BlockLength);
	bufz_fixedBlockLength    = lilv_new_uri(world, LV2_BUF_SIZE__fixedBlockLength);
	bufz_nominalBlockLength  = lilv_new_uri(world, "http://lv2plug.in/ns/ext/buf-size#nominalBlockLength");
	bufz_coarseBlockLength   = lilv_new_uri(world, "http://lv2plug.in/ns/ext/buf-size#coarseBlockLength");
#endif

}

LV2World::~LV2World()
{
	if (!world) {
		return;
	}
#ifdef HAVE_LV2_1_2_0
	lilv_node_free(bufz_coarseBlockLength);
	lilv_node_free(bufz_nominalBlockLength);
	lilv_node_free(bufz_fixedBlockLength);
	lilv_node_free(bufz_powerOf2BlockLength);
#endif
#ifdef LV2_EXTENDED
	lilv_node_free(lv2_noSampleAccurateCtrl);
	lilv_node_free(auto_can_write_automatation);
	lilv_node_free(auto_automation_control);
	lilv_node_free(auto_automation_controlled);
	lilv_node_free(auto_automation_controller);
#endif
	lilv_node_free(patch_Message);
	lilv_node_free(patch_writable);
	lilv_node_free(units_hz);
	lilv_node_free(units_midiNote);
	lilv_node_free(units_db);
	lilv_node_free(units_unit);
	lilv_node_free(units_render);
	lilv_node_free(ui_externalkx);
	lilv_node_free(ui_external);
	lilv_node_free(ui_GtkUI);
	lilv_node_free(time_Position);
	lilv_node_free(rsz_minimumSize);
	lilv_node_free(rdfs_comment);
	lilv_node_free(rdfs_label);
	lilv_node_free(rdfs_range);
	lilv_node_free(midi_MidiEvent);
	lilv_node_free(lv2_designation);
	lilv_node_free(lv2_enumeration);
	lilv_node_free(lv2_freewheeling);
	lilv_node_free(lv2_toggled);
	lilv_node_free(lv2_sampleRate);
	lilv_node_free(lv2_reportsLatency);
	lilv_node_free(lv2_index);
	lilv_node_free(lv2_integer);
	lilv_node_free(lv2_isSideChain);
	lilv_node_free(lv2_inPlaceBroken);
	lilv_node_free(lv2_OutputPort);
	lilv_node_free(lv2_InputPort);
	lilv_node_free(lv2_ControlPort);
	lilv_node_free(lv2_AudioPort);
	lilv_node_free(groups_group);
	lilv_node_free(groups_element);
	lilv_node_free(ext_rangeSteps);
	lilv_node_free(ext_notAutomatic);
	lilv_node_free(ext_causesArtifacts);
	lilv_node_free(ext_expensive);
	lilv_node_free(ext_notOnGUI);
	lilv_node_free(ext_logarithmic);
	lilv_node_free(ev_EventPort);
	lilv_node_free(atom_supports);
	lilv_node_free(atom_eventTransfer);
	lilv_node_free(atom_bufferType);
	lilv_node_free(atom_Sequence);
	lilv_node_free(atom_Chunk);
	lilv_node_free(atom_AtomPort);
	lilv_world_free(world);
	world = NULL;
}

void
LV2World::load_bundled_plugins(bool verbose)
{
	if (!_bundle_checked) {
		if (verbose) {
			cout << "Scanning folders for bundled LV2s: " << ARDOUR::lv2_bundled_search_path().to_string() << endl;
		}

		vector<string> plugin_objects;
		find_paths_matching_filter (plugin_objects, ARDOUR::lv2_bundled_search_path(), lv2_filter, 0, true, true, true);
		for ( vector<string>::iterator x = plugin_objects.begin(); x != plugin_objects.end (); ++x) {
#ifdef PLATFORM_WINDOWS
			string uri = "file:///" + *x + "/";
#else
			string uri = "file://" + *x + "/";
#endif
			LilvNode *node = lilv_new_uri(world, uri.c_str());
			lilv_world_load_bundle(world, node);
			lilv_node_free(node);
		}

		lilv_world_load_all(world);
		_bundle_checked = true;
	}
}

LV2PluginInfo::LV2PluginInfo (const char* plugin_uri)
{
	type = ARDOUR::LV2;
	_plugin_uri = strdup(plugin_uri);
}

LV2PluginInfo::~LV2PluginInfo()
{
	free(_plugin_uri);
	_plugin_uri = NULL;
}

PluginPtr
LV2PluginInfo::load(Session& session)
{
	try {
		PluginPtr plugin;
		const LilvPlugins* plugins = lilv_world_get_all_plugins(_world.world);
		LilvNode* uri = lilv_new_uri(_world.world, _plugin_uri);
		if (!uri) { throw failed_constructor(); }
		const LilvPlugin* lp = lilv_plugins_get_by_uri(plugins, uri);
		if (!lp) { throw failed_constructor(); }
		plugin.reset(new LV2Plugin(session.engine(), session, lp, session.frame_rate()));
		lilv_node_free(uri);
		plugin->set_info(PluginInfoPtr(shared_from_this ()));
		return plugin;
	} catch (failed_constructor& err) {
		return PluginPtr((Plugin*)0);
	}

	return PluginPtr();
}

std::vector<Plugin::PresetRecord>
LV2PluginInfo::get_presets (bool /*user_only*/) const
{
	std::vector<Plugin::PresetRecord> p;
#ifndef NO_PLUGIN_STATE
	const LilvPlugin* lp = NULL;
	try {
		PluginPtr plugin;
		const LilvPlugins* plugins = lilv_world_get_all_plugins(_world.world);
		LilvNode* uri = lilv_new_uri(_world.world, _plugin_uri);
		if (!uri) { throw failed_constructor(); }
		lp = lilv_plugins_get_by_uri(plugins, uri);
		if (!lp) { throw failed_constructor(); }
		lilv_node_free(uri);
	} catch (failed_constructor& err) {
		return p;
	}
	assert (lp);
	// see LV2Plugin::find_presets
	LilvNode* lv2_appliesTo = lilv_new_uri(_world.world, LV2_CORE__appliesTo);
	LilvNode* pset_Preset   = lilv_new_uri(_world.world, LV2_PRESETS__Preset);
	LilvNode* rdfs_label    = lilv_new_uri(_world.world, LILV_NS_RDFS "label");

	LilvNodes* presets = lilv_plugin_get_related(lp, pset_Preset);
	LILV_FOREACH(nodes, i, presets) {
		const LilvNode* preset = lilv_nodes_get(presets, i);
		lilv_world_load_resource(_world.world, preset);
		LilvNode* name = get_value(_world.world, preset, rdfs_label);
		bool userpreset = true; // TODO
		if (name) {
			p.push_back (Plugin::PresetRecord (lilv_node_as_string(preset), lilv_node_as_string(name), userpreset));
			lilv_node_free(name);
		}
	}
	lilv_nodes_free(presets);
	lilv_node_free(rdfs_label);
	lilv_node_free(pset_Preset);
	lilv_node_free(lv2_appliesTo);
#endif
	return p;
}

bool
LV2PluginInfo::in_category (const std::string &c) const
{
	// TODO use untranslated lilv_plugin_get_class()
	// match gtk2_ardour/plugin_selector.cc
	return category == c;
}

bool
LV2PluginInfo::is_instrument () const
{
	if (category == "Instrument") {
		return true;
	}
#if 1
	/* until we make sure that category remains untranslated in the lv2.ttl spec
	 * and until most instruments also classify themselves as such, there's a 2nd check:
	 */
	if (n_inputs.n_midi() > 0 && n_inputs.n_audio() == 0 && n_outputs.n_audio() > 0) {
		return true;
	}
#endif
	return false;
}

PluginInfoList*
LV2PluginInfo::discover()
{
	LV2World world;
	world.load_bundled_plugins();
	_world.load_bundled_plugins(true);

	PluginInfoList*    plugs   = new PluginInfoList;
	const LilvPlugins* plugins = lilv_world_get_all_plugins(world.world);

	LILV_FOREACH(plugins, i, plugins) {
		const LilvPlugin* p = lilv_plugins_get(plugins, i);
		const LilvNode* pun = lilv_plugin_get_uri(p);
		if (!pun) continue;
		LV2PluginInfoPtr info(new LV2PluginInfo(lilv_node_as_string(pun)));

		LilvNode* name = lilv_plugin_get_name(p);
		if (!name || !lilv_plugin_get_port_by_index(p, 0)) {
			warning << "Ignoring invalid LV2 plugin "
			        << lilv_node_as_string(lilv_plugin_get_uri(p))
			        << endmsg;
			continue;
		}

		if (lilv_plugin_has_feature(p, world.lv2_inPlaceBroken)) {
			warning << string_compose(
			    _("Ignoring LV2 plugin \"%1\" since it cannot do inplace processing."),
			    lilv_node_as_string(name)) << endmsg;
			lilv_node_free(name);
			continue;
		}

#ifdef HAVE_LV2_1_2_0
		LilvNodes *required_features = lilv_plugin_get_required_features (p);
		if (lilv_nodes_contains (required_features, world.bufz_powerOf2BlockLength) ||
				lilv_nodes_contains (required_features, world.bufz_fixedBlockLength)
		   ) {
			warning << string_compose(
			    _("Ignoring LV2 plugin \"%1\" because its buffer-size requirements cannot be satisfied."),
			    lilv_node_as_string(name)) << endmsg;
			lilv_nodes_free(required_features);
			lilv_node_free(name);
			continue;
		}
		lilv_nodes_free(required_features);
#endif

		info->type = LV2;

		info->name = string(lilv_node_as_string(name));
		lilv_node_free(name);
		ARDOUR::PluginScanMessage(_("LV2"), info->name, false);

		const LilvPluginClass* pclass = lilv_plugin_get_class(p);
		const LilvNode*        label  = lilv_plugin_class_get_label(pclass);
		info->category = lilv_node_as_string(label);

		LilvNode* author_name = lilv_plugin_get_author_name(p);
		info->creator = author_name ? string(lilv_node_as_string(author_name)) : "Unknown";
		lilv_node_free(author_name);

		info->path = "/NOPATH"; // Meaningless for LV2

		/* count atom-event-ports that feature
		 * atom:supports <http://lv2plug.in/ns/ext/midi#MidiEvent>
		 *
		 * TODO: nicely ask drobilla to make a lilv_ call for that
		 */
		int count_midi_out = 0;
		int count_midi_in = 0;
		for (uint32_t i = 0; i < lilv_plugin_get_num_ports(p); ++i) {
			const LilvPort* port  = lilv_plugin_get_port_by_index(p, i);
			if (lilv_port_is_a(p, port, world.atom_AtomPort)) {
				LilvNodes* buffer_types = lilv_port_get_value(
					p, port, world.atom_bufferType);
				LilvNodes* atom_supports = lilv_port_get_value(
					p, port, world.atom_supports);

				if (lilv_nodes_contains(buffer_types, world.atom_Sequence)
						&& lilv_nodes_contains(atom_supports, world.midi_MidiEvent)) {
					if (lilv_port_is_a(p, port, world.lv2_InputPort)) {
						count_midi_in++;
					}
					if (lilv_port_is_a(p, port, world.lv2_OutputPort)) {
						count_midi_out++;
					}
				}
				lilv_nodes_free(buffer_types);
				lilv_nodes_free(atom_supports);
			}
		}

		info->n_inputs.set_audio(
			lilv_plugin_get_num_ports_of_class(
				p, world.lv2_InputPort, world.lv2_AudioPort, NULL));
		info->n_inputs.set_midi(
			lilv_plugin_get_num_ports_of_class(
				p, world.lv2_InputPort, world.ev_EventPort, NULL)
			+ count_midi_in);

		info->n_outputs.set_audio(
			lilv_plugin_get_num_ports_of_class(
				p, world.lv2_OutputPort, world.lv2_AudioPort, NULL));
		info->n_outputs.set_midi(
			lilv_plugin_get_num_ports_of_class(
				p, world.lv2_OutputPort, world.ev_EventPort, NULL)
			+ count_midi_out);

		info->unique_id = lilv_node_as_uri(lilv_plugin_get_uri(p));
		info->index     = 0; // Meaningless for LV2

		plugs->push_back(info);
	}

	return plugs;
}