/*
 * Copyright (C) 2008-2012 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2008-2017 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2008-2019 David Robillard <d@drobilla.net>
 * Copyright (C) 2012-2023 Robin Gareus <robin@gareus.org>
 * Copyright (C) 2013-2018 John Emmas <john@creativepost.co.uk>
 * Copyright (C) 2013 Michael R. Fisher <mfisher@bketech.com>
 * Copyright (C) 2014-2016 Tim Mayberry <mojofunk@gmail.com>
 * Copyright (C) 2016-2017 Damien Zammit <damien@zamaudio.com>
 * Copyright (C) 2016 Nick Mainsbridge <mainsbridge@gmail.com>
 * Copyright (C) 2017 Johannes Mueller <github@johannes-mueller.org>
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 "pbd/file_utils.h"
#include "pbd/stl_delete.h"
#include "pbd/compose.h"
#include "pbd/error.h"
#include "pbd/locale_guard.h"
#include "pbd/pthread_utils.h"
#include "pbd/replace_all.h"
#include "pbd/xml++.h"

#ifdef PLATFORM_WINDOWS
#include <shlobj.h> // CSIDL_*
#include "pbd/windows_special_dirs.h"
#endif

#include "temporal/superclock.h"

#ifdef WAF_BUILD
#include "libardour-config.h"
#endif

#include "ardour/audio_buffer.h"
#include "ardour/audioengine.h"
#include "ardour/directory_names.h"
#include "ardour/debug.h"
#include "ardour/lv2_evbuf.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>

#ifdef HAVE_LV2_1_18_6
#include <lv2/atom/atom.h>
#include <lv2/atom/forge.h>
#include <lv2/log/log.h>
#include <lv2/midi/midi.h>
#include <lv2/port-props/port-props.h>
#include <lv2/presets/presets.h>
#include <lv2/state/state.h>
#include <lv2/time/time.h>
#include <lv2/worker/worker.h>
#include <lv2/resize-port/resize-port.h>
#include <lv2/ui/ui.h>
#include <lv2/units/units.h>
#include <lv2/patch/patch.h>
#include <lv2/port-groups/port-groups.h>
#include <lv2/parameters/parameters.h>
#include <lv2/buf-size/buf-size.h>
#include <lv2/options/options.h>
#else
#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>
#include <lv2/lv2plug.in/ns/ext/parameters/parameters.h>
#include <lv2/lv2plug.in/ns/ext/buf-size/buf-size.h>
#include <lv2/lv2plug.in/ns/ext/options/options.h>
#endif

#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;
using namespace Temporal;

bool          LV2Plugin::force_state_save      = false;
int32_t       LV2Plugin::_ui_style_flat        = 0;
int32_t       LV2Plugin::_ui_style_boxy        = 0;
uint32_t      LV2Plugin::_ui_background_color  = 0x000000ff; // RGBA
uint32_t      LV2Plugin::_ui_foreground_color  = 0xffffffff; // RGBA
uint32_t      LV2Plugin::_ui_contrasting_color = 0x33ff33ff; // RGBA
unsigned long LV2Plugin::_ui_transient_win_id  = 0;


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* ext_displayPriority;
	LilvNode* groups_group;
	LilvNode* groups_element;
	LilvNode* lv2_AudioPort;
	LilvNode* lv2_ControlPort;
	LilvNode* lv2_InputPort;
	LilvNode* lv2_OutputPort;
	LilvNode* lv2_connectionOptional;
	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* time_beatsPerMin;
	LilvNode* ui_GtkUI;
	LilvNode* ui_X11UI;
	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;
	LilvNode* opts_requiredOptions;
	LilvNode* bufz_powerOf2BlockLength;
	LilvNode* bufz_fixedBlockLength;
	LilvNode* bufz_nominalBlockLength;
	LilvNode* bufz_coarseBlockLength;
	LilvNode* state_loadDefaultState;

#ifdef LV2_EXTENDED
	LilvNode* lv2_noSampleAccurateCtrl;
	LilvNode* routing_connectAllOutputs; // lv2:optionalFeature
	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
	LilvNode* inline_display_interface; // lv2:extensionData
	LilvNode* inline_display_in_gui; // lv2:optionalFeature
	LilvNode* inline_mixer_control; // lv2:PortProperty
	LilvNode* export_interface; // lv2:extensionData
#endif

private:
	bool _bundle_checked;
};

static LV2World _world;

static bool
is_inside_bundle (std::string const& bundle_dir, std::string path)
{
	assert (Glib::file_test (bundle_dir, Glib::FILE_TEST_IS_DIR | Glib::FILE_TEST_EXISTS));

	if (bundle_dir.size () > path.size ()) {
		return false;
	}
	if (bundle_dir == path) {
		return true;
	}
	if (path == Glib::path_get_dirname (path)) {
		/* path must be root */
		return false;
	}
	while (bundle_dir.size () < path.size ()) {
		/* step up, compare with bundle_dir */
		path = Glib::path_get_dirname (path);
		if (bundle_dir == path) {
			return true;
		}
	}
	return false;
}

/* 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);
}

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;

	float fvalue = 0.0f;
	if (type == URIMap::instance ().urids.atom_Float) {
		fvalue = *(const float*)value;
	} else if (type == URIMap::instance ().urids.atom_Double) {
		fvalue = static_cast<float> (*(const double*)value);
	} else if (type == URIMap::instance ().urids.atom_Int) {
		fvalue = static_cast<float> (*(const int32_t*)value);
	} else if (type == URIMap::instance ().urids.atom_Long) {
		fvalue = static_cast<float> (*(const int64_t*)value);
	} else {
		error << string_compose (
		  _("LV2<%1>: Preset value for port '%2' has unsupported datatype <%3>"),
		  self->name (),
		  port_symbol,
		  self->uri_map ().id_to_uri(type));
	}

	const uint32_t port_index = self->port_index(port_symbol);
	if (port_index != (uint32_t)-1) {
		self->set_parameter(port_index, fvalue, 0);
		self->PresetPortSetValue (port_index, fvalue); /* EMIT SIGNAL */
	}
}

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

void
LV2Plugin::midnam_update (LV2_Midnam_Handle handle)
{
	LV2Plugin* plugin = (LV2Plugin*)handle;
	plugin->_midnam_dirty = true;
	plugin->UpdateMidnam (); /* EMIT SIGNAL */
}

void
LV2Plugin::bankpatch_notify (LV2_BankPatch_Handle handle, uint8_t chn, uint32_t bank, uint8_t pgm)
{
	LV2Plugin* plugin = (LV2Plugin*)handle;
	if (chn > 15) {
		return;
	}
	plugin->seen_bankpatch = true;
	if (pgm > 127 || bank > 16383) {
		plugin->_bankpatch[chn] = UINT32_MAX;
	} else {
		plugin->_bankpatch[chn] = (bank << 7) | pgm;
	}
	plugin->BankPatchChange (chn); /* 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)
	       , opts_iface(0)
	       , state(0)
	       , block_length(0)
	       , options(0)
#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;
	const LV2_Options_Interface* opts_iface;
	LilvState*                   state;
	LV2_Atom_Forge               forge;
	LV2_Atom_Forge               ui_forge;
	int32_t                      block_length;
	LV2_Options_Option*          options;
#ifdef LV2_EXTENDED
	LV2_Inline_Display*          queue_draw;
	LV2_Midnam*                  midnam;
	LV2_BankPatch*               bankpatch;
#endif
};

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

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

	XMLNode root (other.state_node_name ());
	other.add_state (&root);
	set_state (root, Stateful::current_state_version);

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

	latency_compute_run();
}

void
LV2Plugin::init(const void* c_plugin, samplecnt_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<samplepos_t>::max();
	_next_cycle_speed       = 1.0;
	_next_cycle_beat        = 0.0;
	_current_bpm            = 0.0;
	_prev_time_scale        = 0.0;
	_seq_size               = _engine.raw_buffer_size(DataType::MIDI);
	_state_version          = 0;
	_was_activated          = false;
	_has_state_interface    = false;
	_can_write_automation   = false;
#ifdef LV2_EXTENDED
	_display_interface      = 0;
	_export_interface       = 0;
	_inline_display_in_gui  = false;
#endif
	_max_latency            = 0;
	_current_latency        = 0;
	_impl->block_length     = _session.get_block_size();

	_sample_rate = rate;
	_fsample_rate = rate;

	_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;
	_block_length_feature.URI    = LV2_BUF_SIZE__boundedBlockLength;
	_block_length_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 (15, sizeof(LV2_Feature*));
	_features[0] = &_instance_access_feature;
	_features[1] = &_data_access_feature;
	_features[2] = &_make_path_feature;
	_features[3] = _uri_map.urid_map_feature();
	_features[4] = _uri_map.urid_unmap_feature();
	_features[5] = &_log_feature;
	_features[6] = &_def_state_feature;
	_features[7] = &_block_length_feature;

	unsigned n_features = 8;

	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;

	_impl->bankpatch = (LV2_BankPatch*)
		malloc (sizeof(LV2_BankPatch));
	_impl->bankpatch->handle = this;
	_impl->bankpatch->notify = bankpatch_notify;

	_bankpatch_feature.URI  = LV2_BANKPATCH__notify;
	_bankpatch_feature.data = _impl->bankpatch;
	_features[n_features++]  = &_bankpatch_feature;
#endif

	LV2_URID atom_Int   = _uri_map.uri_to_id(LV2_ATOM__Int);
	LV2_URID atom_Bool  = _uri_map.uri_to_id(LV2_ATOM__Bool);
	LV2_URID atom_Long  = _uri_map.uri_to_id(LV2_ATOM__Long);
	LV2_URID atom_Float = _uri_map.uri_to_id(LV2_ATOM__Float);

	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)
	static const int32_t rt_policy = PBD_SCHED_FIFO;
	static const int32_t rt_priority = pbd_absolute_rt_priority (PBD_SCHED_FIFO, PBD_RT_PRI_PROC);
	static const int32_t hw_concurrency = how_many_dsp_threads ();
	/* 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(LV2_PARAMETERS__sampleRate),
		  sizeof(float), atom_Float, &_fsample_rate },
		{ 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, _uri_map.uri_to_id("http://ardour.org/lv2/threads/#schedPolicy"),
		  sizeof(int32_t), atom_Int, &rt_policy },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id("http://ardour.org/lv2/threads/#schedPriority"),
		  sizeof(int32_t), atom_Int, &rt_priority },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id("http://ardour.org/lv2/threads/#concurrency"),
		  sizeof(int32_t), atom_Int, &hw_concurrency },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id("http://lv2plug.in/ns/extensions/ui#backgroundColor"),
		  sizeof(int32_t), atom_Int, &_ui_background_color },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id("http://lv2plug.in/ns/extensions/ui#foregroundColor"),
		  sizeof(int32_t), atom_Int, &_ui_foreground_color },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id("http://lv2plug.in/ns/extensions/ui#contrastingColor"),
		  sizeof(int32_t), atom_Int, &_ui_contrasting_color },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id("http://lv2plug.in/ns/extensions/ui#scaleFactor"),
		  sizeof(float), atom_Float, &ARDOUR::ui_scale_factor },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id("http://ardour.org/lv2/theme/#styleBoxy"),
		  sizeof(int32_t), atom_Bool, &_ui_style_boxy },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id("http://ardour.org/lv2/theme/#styleFlat"),
		  sizeof(int32_t), atom_Bool, &_ui_style_flat },
		{ LV2_OPTIONS_INSTANCE, 0, _uri_map.uri_to_id("http://kxstudio.sf.net/ns/lv2ext/props#TransientWindowId"),
		  sizeof(int32_t), atom_Long, &_ui_transient_win_id },
		{ 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;

#ifdef LV2_EXTENDED
	seen_bankpatch = false;
	for (uint32_t chn = 0; chn < 16; ++chn) {
		_bankpatch[chn] = UINT32_MAX;
	}
#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);

	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);

#ifdef LV2_EXTENDED
	_midname_interface = (const LV2_Midnam_Interface*)
		extension_data (LV2_MIDNAM__interface);
	if (_midname_interface) {
		_midnam_dirty = true;
		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();
	}

	LilvNodes* optional_features = lilv_plugin_get_optional_features (plugin);
	if (lilv_nodes_contains (optional_features, _world.bufz_coarseBlockLength)) {
		_no_sample_accurate_ctrl = true;
	}

#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.routing_connectAllOutputs)) {
		_connect_all_audio_outputs = true;
	}
	if (lilv_nodes_contains (optional_features, _world.auto_can_write_automatation)) {
		_can_write_automation = true;
	}
	if (lilv_plugin_has_extension_data(plugin, _world.inline_display_interface)) {
		_display_interface = (const LV2_Inline_Display_Interface*) extension_data (LV2_INLINEDISPLAY__interface);
	}
#ifndef NDEBUG
	else if (extension_data (LV2_INLINEDISPLAY__interface)) {
		warning << string_compose(_("LV2: Plugin '%1' has inline-display extension without lv2:extensionData meta-data "), name ()) << endmsg;
	}
#endif
	if (lilv_nodes_contains (optional_features, _world.inline_display_in_gui)) {
		_inline_display_in_gui = true;
	}
	if (lilv_plugin_has_extension_data(plugin, _world.export_interface)) {
		_export_interface = (const LV2_Export_Interface*) extension_data (LV2_EXPORT__interface);
	}
#endif
	lilv_nodes_free(optional_features);

	/* Snapshot default state -- https://lv2plug.in/ns/ext/state#loadDefaultState */
	LilvState* state = NULL;

	LilvNodes* required_features = lilv_plugin_get_required_features (plugin);
	if (lilv_nodes_contains (required_features, _world.state_loadDefaultState)) {
		state = lilv_state_new_from_world(_world.world, _uri_map.urid_map(), lilv_plugin_get_uri(_impl->plugin));
	}
	lilv_nodes_free (required_features);

	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.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 if (lilv_port_has_property(_impl->plugin, port, _world.lv2_connectionOptional)) {
			flags |= PORT_OTHOPT; // unknown data type but connection optional
		} else {
			error << string_compose("LV2: \"%1\" port %2 has unsupported or unknown 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);

	const LilvPort* bpmport = lilv_plugin_get_port_by_designation(plugin, _world.lv2_InputPort, _world.time_beatsPerMin);
	if (bpmport) {
		_bpm_control_port_index = lilv_port_get_index (plugin, bpmport);
	}

	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.sample_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 {
				_shadow_data[i] = 0;
			}
			_control_data[i] = _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
		const LilvUI*   this_ui      = NULL;
		const LilvNode* this_ui_type = NULL;
#if ! (defined(__APPLE__) || defined(PLATFORM_WINDOWS))
		// Always prefer X11 UIs...
		LILV_FOREACH(uis, i, uis) {
			const LilvUI* ui = lilv_uis_get(uis, i);
			if (lilv_ui_is_a(ui, _world.ui_X11UI) &&
			    lilv_ui_is_supported (ui,
			                          suil_ui_supported,
			                          _world.ui_GtkUI,
			                          &this_ui_type)) {
				this_ui = ui;
				break;
			}
		}
#endif
		// Then anything else...
		if (this_ui == NULL) {
			LILV_FOREACH(uis, i, uis) {
				const LilvUI* ui = lilv_uis_get(uis, i);
				if (lilv_ui_is_supported (ui,
				                         suil_ui_supported,
				                         _world.ui_GtkUI,
				                         &this_ui_type)) {
					this_ui = ui;
					break;
				}
			}
		}
		// Found one that is supported by SUIL?...
		if (this_ui != NULL) {
			_impl->ui      = this_ui;
			_impl->ui_type = this_ui_type;
		}
#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();

	/* 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);
	}
	if (state) {
		lilv_state_restore (state, _impl->instance, set_port_value, this, 0, _features);
		lilv_state_free(state);
	}
}

int
LV2Plugin::set_block_size (pframes_t nframes)
{
	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},
			{ LV2_OPTIONS_INSTANCE, 0, 0, 0, 0, NULL }
		};
		_impl->opts_iface->set (_impl->instance->lv2_handle, block_size_option);
	}

	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()
	 */
	return _no_sample_accurate_ctrl;
}

bool
LV2Plugin::connect_all_audio_outputs () const
{
	return _connect_all_audio_outputs;
}

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);
	free(_impl->options);
#ifdef LV2_EXTENDED
	free(_impl->queue_draw);
	free(_impl->midnam);
	free(_impl->bankpatch);
#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) {
			lv2_evbuf_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
{
	return _impl->ui && (lilv_ui_is_a(_impl->ui, _world.ui_external) ||
	                     lilv_ui_is_a(_impl->ui, _world.ui_externalkx));
}

bool
LV2Plugin::is_external_kx() const
{
	return _impl->ui && 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;
}

bool
LV2Plugin::inline_display_in_gui () {
	return _inline_display_in_gui;
}

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 || !_midnam_dirty) {
		return rv;
	}
	char* midnam = _midname_interface->midnam ((void*)_impl->instance->lv2_handle);
	if (midnam) {
		rv = MIDI::Name::MidiPatchManager::instance().update_custom_midnam (midnam_model(), 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);
	if (rv) {
		UpdatedMidnam ();
		_midnam_dirty = false;
	}
	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;
}

int
LV2Plugin::setup_export (const char* fn, LV2_Options_Option const* options)
{
	if (!_export_interface) {
		return -1;
	}

	return _export_interface->setup ((void*)_impl->instance->lv2_handle, fn, options);
}

int
LV2Plugin::finalize_export ()
{
	if (!_export_interface) {
		return -1;
	}
	return _export_interface->finalize ((void*)_impl->instance->lv2_handle);
}

#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, sampleoffset_t when)
{
	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, when);
}

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 "";
}

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);

		std::string xternal_dir = _session.externals_dir ();

		if (!_plugin_state_dir.empty()) {
			xternal_dir = Glib::build_filename (_plugin_state_dir, externals_dir_name);
			g_mkdir_with_parents(xternal_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(),
			xternal_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);
				g_rmdir (xternal_dir.c_str()); // try remove unused dir
				--_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));
	}
}

static LilvNode*
get_value(LilvWorld* world, const LilvNode* subject, const LilvNode* predicate)
{
	return lilv_world_get(world, subject, predicate, NULL);
}

void
LV2Plugin::find_presets()
{
	/* see also LV2PluginInfo::get_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");
	LilvNode* rdfs_comment  = lilv_new_uri(_world.world, LILV_NS_RDFS "comment");
	LilvNode* rdfs_seeAlso  = lilv_new_uri(_world.world, LILV_NS_RDFS "seeAlso");

	/* query plugins bundle path */
	const LilvNode* const bundle_uri = lilv_plugin_get_bundle_uri(_impl->plugin);
	assert (bundle_uri);
	char* bundle_path = lilv_file_uri_parse(lilv_node_as_uri(bundle_uri), NULL);
	std::string bundle_dir = Glib::path_get_dirname (bundle_path);
	lilv_free (bundle_path);

	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);
		LilvNode* comment = get_value(_world.world, preset, rdfs_comment);
		LilvNode* seealso = get_value(_world.world, preset, rdfs_seeAlso);

		/* TODO properly identify user vs factory presets.
		 * here's an indirect condition: only factory presets can have comments
		 */
		bool userpreset = comment ? false : true;
		/* if the preset ttl file is read-only, or part of the plugin bundle
		 * it is also assumed to be a factory preset */
		if (seealso) {
			char* pset_ttl = lilv_file_uri_parse (lilv_node_as_uri(seealso), NULL);
			if (!exists_and_writable (pset_ttl)) {
				/* no write access */
				userpreset = false;
			} else if (is_inside_bundle (bundle_dir, pset_ttl)) {
				userpreset = false;
			}
			lilv_free (pset_ttl);
		}
		// TODO also check for 3rd part preset bundles
		// > 1 preset in any give manifest.ttl or preset.ttl

		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,
				                               comment ? lilv_node_as_string (comment) : ""
			                               )));
			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;
		}
		if (comment) {
			lilv_node_free(comment);
		}
		if (seealso) {
			lilv_node_free(seealso);
		}
	}
	lilv_nodes_free(presets);

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

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";
#ifdef PLATFORM_WINDOWS
	/* http://lv2plug.in/pages/filesystem-hierarchy-standard.html */
	std::string appdata = PBD::get_win_special_folder_path (CSIDL_APPDATA);
	if (appdata.empty ()) {
		// TODO consider a fallback location
		return "";
	}
	const string bundle = Glib::build_filename (
			appdata, "LV2", prefix + "_" + base_name + ".lv2");
#else
	/* while macOS/OSX user-specific path is
	 *
	 *   $HOME/Library/Audio/Plug-Ins/LV2/
	 *
	 * liblilv's LV2 search path on all unices does include ~/.lv2/
	 * Ardour has been saving lv2 presets to ~/.lv2 for along time,
	 * so just keep them there.
	 */
	const string bundle    = Glib::build_filename(
		Glib::get_home_dir(),
		Glib::build_filename(".lv2", prefix + "_" + base_name + ".lv2"));
#endif

	/* delete reference to old preset (if any) */
#if 0 // prefer this when https://github.com/lv2/lilv/issues/37 is resolved
	do_remove_preset (name);
#else
	/* this works around https://github.com/lv2/lilv/issues/37
	 *
	 * do_remove_preset() calls lilv_state_delete(); That
	 * deletes all mapped files without re-creating them.
	 * So for the time being we just leave them in place.
	 */
	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());
	lilv_world_unload_resource(_world.world, node_preset);
	lilv_world_unload_bundle(_world.world, node_bundle);
	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)
{
	/* 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);
}

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

void
LV2Plugin::add_slave (std::shared_ptr<Plugin> p, bool)
{
	std::shared_ptr<LV2Plugin> lv2 = std::dynamic_pointer_cast<LV2Plugin> (p);
	if (lv2) {
		Glib::Threads::Mutex::Lock lm (_slave_lock);
		_slaves.insert (lv2);
	}
}

void
LV2Plugin::remove_slave (std::shared_ptr<Plugin> p)
{
	std::shared_ptr<LV2Plugin> lv2 = std::dynamic_pointer_cast<LV2Plugin> (p);
	if (lv2) {
		Glib::Threads::Mutex::Lock lm (_slave_lock);
		_slaves.erase (lv2);
	}
}

void
LV2Plugin::set_non_realtime (bool yn)
{
	_non_realtime = yn;
}

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;

	if (dest->write_space () < buf_size) {
		/* Do not write partial message */
		return false;
	}

	uint8_t* buf = (uint8_t*) g_alloca (sizeof (uint8_t) * 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.sample_rate () / 3000.f);
		rbs = max((size_t) bufsiz * std::max (8, fact), rbs);
		_from_ui = new RingBuffer<uint8_t>(rbs);
	}

	if (_from_ui->write_space () < size) {
		error << string_compose (_("LV2<%1>: Error writing from UI to plugin"), name()) << endmsg;
		return false;
	}

	if (!write_to(_from_ui, index, protocol, size, body)) {
		error << string_compose (_("LV2<%1>: Error writing from UI to plugin"), name()) << endmsg;
		return false;
	}

	Glib::Threads::Mutex::Lock lm (_slave_lock, Glib::Threads::TRY_LOCK);
	if (lm.locked()) {
		for (auto const& i : _slaves) {
			i->write_from_ui (index, protocol, size, body);
		}
	}

	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 << string_compose (_("LV2<%1>: Error writing from plugin to UI"), name()) << 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, DoubleableBeats(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 << string_compose (_("LV2<%1>: set_property called with unset patch_port_in_index"), name ()) << endmsg;
		return;
	} else if (value.type() == Variant::NOTHING) {
		error << string_compose (_("LV2<%1>: set_property called with void value"), name ()) << 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", "%.0f");
			} 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<%1>: property <%2> has no range datatype, ignoring"),
			                          name(), 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<%1>: property <%2> has unsupported datatype <%3>"),
			                        name(), 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));

		_property_values[desc.key] = Variant();

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

Variant
LV2Plugin::get_property_value (uint32_t prop_id) const
{
	std::map<uint32_t, Variant>::const_iterator it;
	if ((it = _property_values.find (prop_id)) == _property_values.end()) {
		return Variant();
	}
	return it->second;
}

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 << string_compose (_("LV2<%1>: Error reading message header from Plugin => UI RingBuffer"), name()) << endmsg;
			break;
		}
		vector<uint8_t> body(msg.size);
		if (_to_ui->read(&body[0], msg.size) != msg.size) {
			error << string_compose (_("LV2<%1>: Error reading message body from Plugin => UI RingBuffer"), name()) << 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 << string_compose (_("LV2<%1>: Bad node sent to LV2Plugin::set_state"), name()) << endmsg;
		return -1;
	}

	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 << string_compose (_("LV2<%1>: port has no symbol '%2', ignored"), name(), sym) << 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 << string_compose (_("LV2<%1>: port '%2' has known index, ignored "), name(), sym) << endmsg;
			continue;
		}

		float val;
		if (!child->get_property("value", val)) {
			warning << string_compose (_("LV2<%1>: port no value, ignored "), name(), sym) << endmsg;
			continue;
		}

		set_parameter(port_id, val, 0);
	}

	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 ("");
	}

	/* Do not call latency_compute_run() concurrently with connect_and_run().
	 * So far this can only guaranteed when the session is loading,
	 * and the plugin has not been added to the processor chain.
	 *
	 * Ideally this would clso be called when copying a plugin from another track,
	 * but NOT when copying the state from a plugin to another (active) plugin
	 * instance.
	 */
	if (_session.loading ()) {
		latency_compute_run();
	}

	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<%1>: get descriptor of non-existent port %2", name(), 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);
	LilvNode* display_priority  = lilv_port_get(_impl->plugin, port, _world.ext_displayPriority);

	// 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)); // XXX leaks
	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.sample_rate ();
		desc.upper *= _session.sample_rate ();
	}

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

#ifdef LV2_EXTENDED
	desc.inline_ctrl = lilv_port_has_property(_impl->plugin, port, _world.inline_mixer_control);
#endif

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

	desc.update_steps();

	lilv_node_free(def);
	lilv_node_free(min);
	lilv_node_free(max);
	lilv_node_free(steps);
	lilv_node_free(display_priority);
	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;
			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);
			// TODO set iod.bus_number (nth group)
		}
		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()) ) {

		const LilvPort* port = lilv_plugin_get_port_by_index(_impl->plugin, which.id());

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

		const LilvPort* fwport = lilv_plugin_get_port_by_designation(_impl->plugin, _world.lv2_InputPort, _world.lv2_freewheeling);
		if (fwport && fwport == port) {
			return X_("hidden");
		}

		const LilvPort* bpmport = lilv_plugin_get_port_by_designation(_impl->plugin, _world.lv2_InputPort, _world.time_beatsPerMin);
		if (bpmport && bpmport == port) {
			return X_("hidden");
		}

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

		if (lilv_port_has_property(_impl->plugin, port, _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 "??";
	}
}

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

samplecnt_t
LV2Plugin::plugin_latency() const
{
	if (_latency_control_port) {
		return (samplecnt_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, std::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));
	}
	else if (i == _bpm_control_port_index) {
		_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);

			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);
		}
	}

	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,
		                                    _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,
               TempoMetric const & t,
               BBT_Time const &    bbt,
               double              speed,
               double              time_scale,
               double              bpm,
               samplepos_t         position,
               samplecnt_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 / (float) Temporal::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_value());
	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);
	lv2_atom_forge_key(forge, urids.time_scale);
	lv2_atom_forge_float(forge, time_scale);
#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 / (float) Temporal::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);
	lv2_atom_forge_key(forge, urids.time_scale);
	lv2_atom_forge_float(forge, time_scale);
#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,
		samplepos_t start, samplepos_t end, double speed,
		ChanMapping const& in_map, ChanMapping const& out_map,
		pframes_t nframes, samplecnt_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();

	/* remain at zero during pre-roll at zero */
	speed = end > 0 ? speed : 0;
	samplepos_t start0 = std::max (samplepos_t (0), start);

	TempoMap::SharedPtr tmap (TempoMap::use());
	TempoMetric metric (tmap->metric_at (timepos_t (start0)));

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

	if (_bpm_control_port) {

		const double bpm = tmap->quarters_per_minute_at (timepos_t (start0));

		if (*_bpm_control_port != bpm) {
			AutomationCtrlPtr c = get_automation_control (_bpm_control_port_index);
			if (c && c->ac) {
				/* may be NULL for replicated instances - only one custom UI/ctrl */
				c->ac->Changed (false, Controllable::NoGroup); /* EMIT SIGNAL */
			}
		}

		*_bpm_control_port = bpm;
	}

#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;

	TempoMapPoints tempo_map_points;
	tempo_map_points.reserve (16);
	bool got_grid = false;

	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(0);
			} 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(0);
			}
		} else if (flags & 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);
				} else {
					/* Valid pin mapping, but no corresponding port-buffers */
					valid = false;
				}
			} 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)) {
					Temporal::BBT_Time bbt (metric.bbt_at (timepos_t (start0)));
					double bpm = (superclock_ticks_per_second() * 60.) / metric.superclocks_per_note_type_at_superclock (samples_to_superclock (start0, TEMPORAL_SAMPLE_RATE));
					double time_scale = Port::speed_ratio ();
					double beatpos = (bbt.bars - 1) * metric.meter().divisions_per_bar()
						+ (bbt.beats - 1)
						+ (bbt.ticks / Temporal::ticks_per_beat);
					beatpos *= metric.tempo().note_type() / 4.0;
					if (start != _next_cycle_start ||
							speed != _next_cycle_speed ||
							time_scale != _prev_time_scale ||
							rint (100 * beatpos) != rint(100 * _next_cycle_beat) ||
							bpm != _current_bpm) {
						// Transport or Tempo has changed, write position at cycle start
						write_position(&_impl->forge, _ev_buffers[port_index],
						               metric, bbt, speed, time_scale,  bpm, start, 0);
					}

					if (!got_grid) {
						got_grid = true;
						tmap->get_grid (grid_iterator, tempo_map_points,
						                samples_to_superclock (start0, TEMPORAL_SAMPLE_RATE),
						                samples_to_superclock (end, TEMPORAL_SAMPLE_RATE), 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 samplepos_t  tend = end;

				/* move to next explicit point
				 * (if any)
				 */

				TempoMapPoints::const_iterator tempo_map_point (tempo_map_points.begin());

				while (tempo_map_point != tempo_map_points.end()) {
					tempo_map_point++;
					if (tempo_map_point != tempo_map_points.end()) {
						if (tempo_map_point->is_explicit()) {
							break;
						}
					}
				}

				while (m != m_end || ((tempo_map_point != tempo_map_points.end()) && ((*tempo_map_point).sample(TEMPORAL_SAMPLE_RATE) < tend))) {

					if (m != m_end && ((tempo_map_point == tempo_map_points.end()) || (*tempo_map_point).sample(TEMPORAL_SAMPLE_RATE) > (*m).time() + offset)) {

						const Evoral::Event<samplepos_t> ev (*m, false);

						if (ev.time() >= offset && ev.time() < offset + nframes) {
							LV2_Evbuf_Iterator eend = lv2_evbuf_end(_ev_buffers[port_index]);
							lv2_evbuf_write(&eend, ev.time() - offset, 0, type, ev.size(), ev.buffer());
						}

						++m;

					} else {
						assert (tempo_map_point != tempo_map_points.end());
						const samplepos_t sample = tempo_map_point->sample (TEMPORAL_SAMPLE_RATE);
						const Temporal::BBT_Time bbt = tempo_map_point->bbt();
						double bpm = (superclock_ticks_per_second() * 60) / tempo_map_point->superclocks_per_note_type_at_superclock (tempo_map_point->sclock());

						write_position(&_impl->forge, _ev_buffers[port_index],
						               *tempo_map_point, bbt, speed, Port::speed_ratio (),
						               bpm, sample, sample - start);

						/* move to next explicit point
						 * (if any)
						 */

						while (tempo_map_point != tempo_map_points.end()) {
							tempo_map_point++;
							if (tempo_map_point != tempo_map_points.end()) {
								if (tempo_map_point->is_explicit()) {
									break;
								}
							}
						}
					}

				}

			} else if (!valid) {
				/* Nothing we understand or care about, but we have
				 * to provide valid buffers for DSP/UI communication.
				 * Note that Atom buffers scratch buffers must not be shared.
				 */
				lv2_evbuf_reset (_atom_ev_buffers[atom_port_index], (flags & PORT_INPUT));
				_ev_buffers[port_index] = _atom_ev_buffers[atom_port_index++];
			}

			buf = lv2_evbuf_get_buffer(_ev_buffers[port_index]);
		} else if(flags & PORT_OTHOPT) {
			// Explicitely connect optional ports that we can not handle to NULL
		} 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 << string_compose (_("LV2<%1>: Error reading message header from UI => Plugin RingBuffer"), name()) << endmsg;
				break;
			}
			vector<uint8_t> body(msg.size);
			if (_from_ui->read(&body[0], msg.size) != msg.size) {
				error << string_compose (_("LV2<%1>: Error reading message body from UI => Plugin RingBuffer"), name()) << 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";
				}
				/* Intercept patch:Set messages from GUIs (custom,
				 * or generic via LV2Plugin::set_property).
				 */
				else if (atom->type == _uri_map.urids.atom_Blank ||
				         atom->type == _uri_map.urids.atom_Object) {
					const LV2_Atom_Object* obj = (const 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) {
							/* check if it's a property we know or care about */
							const uint32_t prop_id = ((const LV2_Atom_URID*)property)->body;
							if (_property_values.find (prop_id) != _property_values.end()) {
								Plugin::state_changed ();
							}
						}
					}
				}
			} else {
				error << string_compose (_("LV2<%1>: Received unknown message type from UI"), name()) << 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_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, nframes, offset);
			}
		}
		// Flush MIDI (write back to Ardour MIDI buffers) -- MIDI THRU
		else if ((flags & PORT_OUTPUT) && (flags & 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, nframes, offset);
			}
		}

		// Write messages to UI
		if ((_to_ui || _can_write_automation || _patch_port_out_index != (uint32_t)-1) &&
		    (flags & PORT_OUTPUT) && (flags & 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 samples, subframes, type, size;
				uint8_t* data;
				lv2_evbuf_get(i, &samples, &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, samples, v));
								AutomationCtrlPtr c = get_automation_control (p);
								if (c &&
								     (c->ac->automation_state() == Touch || c->ac->automation_state() == Write)
								   ) {
									samplepos_t when = std::max ((samplepos_t) 0, start + samples - _current_latency);
									assert (start + samples - _current_latency >= 0);
									if (c->guard) {
										c->guard = false;
										c->ac->list()->add (timepos_t (when), v, true, true);
									} else {
										c->ac->set_double (v, timepos_t (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 (timepos_t (std::max ((samplepos_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 (timepos_t (std::max ((samplepos_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) {
							Plugin::state_changed ();
						}
					}
				}

				// 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) {
								const uint32_t prop_id  = ((const LV2_Atom_URID*)property)->body;
								if (_property_values.find (prop_id) != _property_values.end()) {
									if (value->type == _uri_map.urids.atom_Path) {
										const char* path          = (const char*)LV2_ATOM_BODY_CONST(value);
										_property_values[prop_id] = Variant(Variant::PATH, path);
									}
									if (value->type == _uri_map.urids.atom_Float) {
										const float* val          = (const float*)LV2_ATOM_BODY_CONST(value);
										_property_values[prop_id] = Variant(Variant::FLOAT, *val);
									}
									// TODO add support for other props (Int, Bool, ..)

									// TODO: This should emit the control's Changed signal
									PropertyChanged(prop_id, _property_values[prop_id]);
								} else {
									std::cerr << "warning: patch:Set for unknown property" << std::endl;
								}
							} else {
								std::cerr << "warning: patch:Set for unsupported 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 + (start - start0);
	_prev_time_scale = Port::speed_ratio ();

	{
		/* 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.
		 */
		_current_bpm = (superclock_ticks_per_second() * 60.) / metric.superclocks_per_note_type_at_superclock (samples_to_superclock (start0, TEMPORAL_SAMPLE_RATE));
		Temporal::BBT_Time bbt (metric.bbt_at (timepos_t (start0)));
		double beatpos = (bbt.bars - 1) * metric.divisions_per_bar()
		               + (bbt.beats - 1)
		               + (bbt.ticks / Temporal::ticks_per_beat);
		beatpos *= metric.note_value() / 4.0;
		_next_cycle_beat = beatpos + nframes * speed * _current_bpm / (60.f * _session.sample_rate());
	}

	if (_latency_control_port) {
		samplecnt_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_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;
}

std::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);

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

	ret = std::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 || _non_realtime || 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
	 * Note: since Ardour 5, plugins can dynamically change latency
	 * so this call is not required anymore, but doing
	 * an intial silent-run is likely a good idea regardless.
	 */

	bool was_activated = _was_activated;
	activate();

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

	std::vector<LV2_Evbuf*> ev_buffers;
	memset(buffer, 0, sizeof(float) * bufsize);

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

	for (uint32_t port_index = 0; port_index < parameter_count (); ++port_index) {
		PortFlags flags = _port_flags[port_index];
		if (flags & PORT_AUDIO) {
			lilv_instance_connect_port(_impl->instance, port_index, buffer);
		} else if (flags & PORT_SEQUENCE) {
			int buf_size = 8192;
#if 1 /* honor the min port-size here */
			const LilvPort* port  = lilv_plugin_get_port_by_index(_impl->plugin, port_index);
			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)) {
				buf_size = std::max (buf_size, lilv_node_as_int (min_size));
			}
			lilv_nodes_free(min_size_v);
#endif
			ev_buffers.push_back (lv2_evbuf_new (buf_size, _uri_map.urids.atom_Chunk, _uri_map.urids.atom_Sequence));
			void* buf = lv2_evbuf_get_buffer (ev_buffers.back ());
			lilv_instance_connect_port(_impl->instance, port_index, buf);
		} else if (flags & PORT_OTHOPT) {
			lilv_instance_connect_port(_impl->instance, port_index, NULL);
		}
	}

	run (bufsize, true); // XXX prefer run (0, true)

	deactivate();
	if (was_activated) {
		activate();
	}
	while (!ev_buffers.empty ()) {
		lv2_evbuf_free (ev_buffers.back ());
		ev_buffers.pop_back ();
	}
	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);
	ext_displayPriority    = lilv_new_uri(world, LV2_PORT_PROPS__displayPriority);
	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_connectionOptional = lilv_new_uri(world, LV2_CORE__connectionOptional);
	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);
	time_beatsPerMin       = lilv_new_uri(world, LV2_TIME__beatsPerMinute);
	ui_GtkUI               = lilv_new_uri(world, LV2_UI__GtkUI);
	ui_X11UI               = lilv_new_uri(world, LV2_UI__X11UI);
	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);
	opts_requiredOptions   = lilv_new_uri(world, LV2_OPTIONS__requiredOption);
#ifdef LV2_EXTENDED
	lv2_noSampleAccurateCtrl    = lilv_new_uri(world, "http://ardour.org/lv2/ext#noSampleAccurateControls"); // deprecated 2016-09-18
	routing_connectAllOutputs   = lilv_new_uri(world, LV2_ROUTING__connectAllOutputs);
	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);
	inline_display_interface    = lilv_new_uri(world, LV2_INLINEDISPLAY__interface);
	inline_display_in_gui       = lilv_new_uri(world, LV2_INLINEDISPLAY__in_gui);
	inline_mixer_control        = lilv_new_uri(world, "http://ardour.org/lv2/ext#inlineMixerControl");
	export_interface            = lilv_new_uri(world, LV2_EXPORT__interface);
#endif
	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");
	state_loadDefaultState   = lilv_new_uri(world, LV2_STATE_PREFIX "loadDefaultState");
}

LV2World::~LV2World()
{
	if (!world) {
		return;
	}
	lilv_node_free(state_loadDefaultState);
	lilv_node_free(bufz_coarseBlockLength);
	lilv_node_free(bufz_nominalBlockLength);
	lilv_node_free(bufz_fixedBlockLength);
	lilv_node_free(bufz_powerOf2BlockLength);
#ifdef LV2_EXTENDED
	lilv_node_free(lv2_noSampleAccurateCtrl);
	lilv_node_free(routing_connectAllOutputs);
	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);
	lilv_node_free(inline_display_interface);
	lilv_node_free(inline_display_in_gui);
	lilv_node_free(inline_mixer_control);
	lilv_node_free(export_interface);
#endif
	lilv_node_free(patch_Message);
	lilv_node_free(opts_requiredOptions);
	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_X11UI);
	lilv_node_free(ui_GtkUI);
	lilv_node_free(time_beatsPerMin);
	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_connectionOptional);
	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_displayPriority);
	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) {
			info << "Scanning folders for bundled LV2s: " << ARDOUR::lv2_bundled_search_path().to_string() << endmsg;
		}

		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.sample_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;

	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 also  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");
	LilvNode* rdfs_comment  = lilv_new_uri(_world.world, LILV_NS_RDFS "comment");
	LilvNode* rdfs_seeAlso  = lilv_new_uri(_world.world, LILV_NS_RDFS "seeAlso");

	/* query plugins bundle path */
	const LilvNode* const bundle_uri = lilv_plugin_get_bundle_uri(lp);
	assert (bundle_uri);
	char* bundle_path = lilv_file_uri_parse(lilv_node_as_uri(bundle_uri), NULL);
	std::string bundle_dir = Glib::path_get_dirname (bundle_path);
	lilv_free (bundle_path);

	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);
		LilvNode* comment = get_value(_world.world, preset, rdfs_comment);
		LilvNode* seealso = get_value(_world.world, preset, rdfs_seeAlso);

		/* TODO properly identify user vs factory presets.
		 * here's an indirect condition: only factory presets can have comments
		 */
		bool userpreset = comment ? false : true;

		/* if the preset ttl file is read-only, or part of the plugin bundle
		 * it is also assumed to be a factory preset */
		if (seealso) {
			char* pset_ttl = lilv_file_uri_parse (lilv_node_as_uri(seealso), NULL);
			if (!exists_and_writable (pset_ttl)) {
				/* no write access */
				userpreset = false;
			} else if (is_inside_bundle (bundle_dir, pset_ttl)) {
				userpreset = false;
			}
			lilv_free (pset_ttl);
		}
		// TODO also check for 3rd part preset bundles
		// > 1 preset in any give manifest.ttl or preset.ttl

		if ((!user_only || userpreset) && name) {
			p.push_back (Plugin::PresetRecord (lilv_node_as_string(preset), lilv_node_as_string(name), userpreset, comment ? lilv_node_as_string (comment) : ""));
			lilv_node_free(name);
		}

		if (comment) {
			lilv_node_free(comment);
		}
		if (seealso) {
			lilv_node_free(seealso);
		}
	}
	lilv_nodes_free(presets);
	lilv_node_free(rdfs_comment);
	lilv_node_free(rdfs_label);
	lilv_node_free(pset_Preset);
	lilv_node_free(lv2_appliesTo);

	std::sort (p.begin (), p.end ());

	return p;
}

PluginInfoList*
LV2PluginInfo::discover (boost::function <void (std::string const&, PluginScanLogEntry::PluginScanResult, std::string const&, bool)> cb)
{
	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;
		std::string const uri (lilv_node_as_string(pun));
		cb (uri, PluginScanLogEntry::OK, string_compose (_("URI: %1"), uri), true);
		cb (uri, PluginScanLogEntry::OK, string_compose (_("Bundle: %1"), lilv_node_as_uri (lilv_plugin_get_bundle_uri (p))), false);

		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)) {
			cb (uri, PluginScanLogEntry::Error, _("Ignoring invalid LV2 plugin (missing name, no ports)"), false);
			lilv_node_free(name);
			continue;
		}

		if (lilv_plugin_has_feature(p, world.lv2_inPlaceBroken)) {
			cb (uri, PluginScanLogEntry::Error, _("Ignoring LV2 plugin since it cannot do inplace processing."), false);
			lilv_node_free(name);
			continue;
		}

		int err = 0;
		LilvNodes* required_features = lilv_plugin_get_required_features (p);
		LILV_FOREACH(nodes, i, required_features) {
				const char* rf = lilv_node_as_uri (lilv_nodes_get (required_features, i));
				bool ok = false;
				if (!strcmp (rf, "http://lv2plug.in/ns/lv2core#isLive")) { ok = true; }
				if (!strcmp (rf, "http://lv2plug.in/ns/ext/instance-access")) { ok = true; }
				if (!strcmp (rf, "http://lv2plug.in/ns/ext/data-access")) { ok = true; }
				if (!strcmp (rf, LV2_STATE__makePath)) { ok = true; }
				if (!strcmp (rf, LV2_STATE__mapPath)) { ok = true; }
				if (!strcmp (rf, "http://lv2plug.in/ns/ext/state#threadSafeRestore")) { ok = true; }
				if (!strcmp (rf, LV2_STATE_PREFIX "loadDefaultState")) { ok = true; }
				if (!strcmp (rf, LV2_LOG__log)) { ok = true; }
				if (!strcmp (rf, LV2_WORKER__schedule)) { ok = true; }
				if (!strcmp (rf, LV2_URID_MAP_URI)) { ok = true; }
				if (!strcmp (rf, LV2_URID_UNMAP_URI)) { ok = true; }
				if (!strcmp (rf, LV2_BUF_SIZE__boundedBlockLength)) { ok = true; }
				if (!strcmp (rf, "http://lv2plug.in/ns/ext/buf-size#coarseBlockLength" /*LV2_BUF_SIZE__coarseBlockLength*/)) { ok = true; }
				if (!strcmp (rf, LV2_OPTIONS__options)) { ok = true; }
#ifdef LV2_EXTENDED
				if (!strcmp (rf, LV2_INLINEDISPLAY__queue_draw)) { ok = true; }
				if (!strcmp (rf, LV2_MIDNAM__update)) { ok = true; }
				if (!strcmp (rf, LV2_BANKPATCH__notify)) { ok = true; }
#endif
				if (!ok) {
					cb (uri, PluginScanLogEntry::Error, string_compose (_("Unsupported required LV2 feature: '%1'."), rf), false);
					err = 1;
				}
		}

		lilv_nodes_free (required_features);

		if (err) {
			continue;
		}

		LilvNodes* required_options = lilv_world_find_nodes (world.world, lilv_plugin_get_uri (p), world.opts_requiredOptions, NULL);
		if (required_options) {
			LILV_FOREACH(nodes, i, required_options) {
				const char* ro = lilv_node_as_uri (lilv_nodes_get (required_options, i));
				bool ok = false;
				if (!strcmp (ro, LV2_PARAMETERS__sampleRate)) { ok = true; }
				if (!strcmp (ro, LV2_BUF_SIZE__minBlockLength)) { ok = true; }
				if (!strcmp (ro, LV2_BUF_SIZE__maxBlockLength)) { ok = true; }
				if (!strcmp (ro, LV2_BUF_SIZE__sequenceSize)) { ok = true; }
				if (!ok) {
					cb (uri, PluginScanLogEntry::Error, string_compose (_("Unsupported required LV2 option: '%1'."), ro), false);
					err = 1;
				}
			}
		}
		lilv_nodes_free(required_options);

		if (err) {
			continue;
		}

		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);

		cb (uri, PluginScanLogEntry::OK, string_compose (_("LV2 Category: '%1'"), info->category), false);

		/* check main category */
		const char* pcat = lilv_node_as_uri (lilv_plugin_class_get_uri (pclass));
		assert (pcat);
		info->_is_instrument = 0 == strcmp (pcat, LV2_CORE__InstrumentPlugin);
		info->_is_utility    = 0 == strcmp (pcat, LV2_CORE__UtilityPlugin);
		info->_is_analyzer   = 0 == strcmp (pcat, LV2_CORE__AnalyserPlugin);

		/* check parent category, if any */
		const LilvNode* lpc = lilv_plugin_class_get_parent_uri (pclass);
		if (lpc) {
			const char* pcu = lilv_node_as_uri (lpc);
			info->_is_instrument |= 0 == strcmp (pcu, LV2_CORE__InstrumentPlugin);
			info->_is_utility    |= 0 == strcmp (pcu, LV2_CORE__UtilityPlugin);
			info->_is_analyzer   |= 0 == strcmp (pcu, LV2_CORE__AnalyserPlugin);
			cb (uri, PluginScanLogEntry::OK, string_compose (_("LV2 Parent Class URI: '%1'"), pcu), false);
		}

#if 0
		/* iterate over child classes */
		LilvPluginClasses* classes  = lilv_plugin_class_get_children (pclass);
		LILV_FOREACH(plugin_classes, i, classes) {
			const LilvPluginClass* lclass = lilv_plugin_classes_get (classes, i);
			const LilvNode*        lcnode = lilv_plugin_class_get_uri (lclass);
			const LilvNode*        lclbl  = lilv_plugin_class_get_label (lclass);
			const char*            lcuri  = lilv_node_as_uri (lcnode);
			info->_is_instrument |= 0 == strcmp (lcuri, LV2_CORE__InstrumentPlugin);
			info->_is_utility    |= 0 == strcmp (lcuri, LV2_CORE__UtilityPlugin);
			info->_is_analyzer   |= 0 == strcmp (lcuri, LV2_CORE__AnalyserPlugin);
			cb (uri, PluginScanLogEntry::OK, string_compose (_("LV2 Class: '%1'"), lilv_node_as_string (lclbl)), false);
		}
		lilv_plugin_classes_free (classes);
#endif

		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

		int count_midi_out = 0;
		int count_midi_in  = 0;
		int count_atom_out = 0;
		int count_atom_in  = 0;
		int count_ctrl_out = 0;
		int count_ctrl_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_port_is_a(p, port, world.lv2_InputPort)) {
					count_atom_in++;
				} else if (lilv_port_is_a(p, port, world.lv2_OutputPort)) {
					count_atom_out++;
				} else {
					cb (uri, PluginScanLogEntry::Error, _("Found Atom port not marked for input or output."), false);
					err = 1;
				}

				if (!lilv_nodes_contains(buffer_types, world.atom_Sequence)) {
					cb (uri, PluginScanLogEntry::Error, _("Found Atom port without sequence support."), false);
					/* ignore non-sequence Atom ports */
					err = 1;
				}
				else if (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);
			}
			else if (lilv_port_is_a(p, port, world.lv2_ControlPort)) {
				if (lilv_port_is_a(p, port, world.lv2_InputPort)) {
					count_ctrl_in++;
				}
				if (lilv_port_is_a(p, port, world.lv2_OutputPort)) {
					count_ctrl_out++;
				}
			}
			else if (lilv_port_has_property(p, port, world.lv2_connectionOptional)) {
				LilvNode* name = lilv_port_get_name(p, port);
				cb (uri, PluginScanLogEntry::OK, string_compose (_("Ignored optional port %1 ('%2') which has unsupported data type."), i, lilv_node_as_string (name)), false);
				lilv_node_free(name);
			}
			else if (!lilv_port_is_a(p, port, world.lv2_AudioPort)) {
				err = 1;
				LilvNode* name = lilv_port_get_name(p, port);
				cb (uri, PluginScanLogEntry::Error, string_compose (_("Port %1 ('%2') has unsupported data type."), i, lilv_node_as_string (name)), false);
				lilv_node_free(name);
			}
		}

		if (err) {
			continue;
		}

		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

		cb (uri, PluginScanLogEntry::OK, string_compose (
					_("LV2 Ports: Atom-in: %1, Atom-out: %2, Audio-in: %3 Audio-out: %4 MIDI-in: %5  MIDI-out: %6 Ctrl-in: %7 Ctrl-out: %8"),
					count_atom_in, count_atom_out,
					info->n_inputs.n_audio (), info->n_outputs.n_audio (),
					count_midi_in, count_midi_out,
					count_ctrl_in, count_ctrl_out), false);

		if (uri == "urn:ardour:a-vapor" || uri == "urn:ardour:a-atmos") {
			info->internal = true;
			cb (uri, PluginScanLogEntry::OK, "", true);
		}

		plugs->push_back(info);
	}

	return plugs;
}

bool
LV2PluginInfo::is_instrument () const
{
	if (_is_instrument) {
		return true;
	}
	return PluginInfo::is_instrument ();
}

bool
LV2PluginInfo::is_utility () const
{
	if (_is_utility) {
		return true;
	}
	return PluginInfo::is_utility ();
}

bool
LV2PluginInfo::is_analyzer () const
{
	if (_is_analyzer) {
		return true;
	}
	return PluginInfo::is_analyzer ();
}
