Add 'props.lv2/' from commit '28e396adb8d82630fc7f6b5b141b47f2c4deab41'

git-subtree-dir: props.lv2
git-subtree-mainline: 12e61f66451039eab6580d562b3e8e87fb5e26d5
git-subtree-split: 28e396adb8d82630fc7f6b5b141b47f2c4deab41

8 files changed, 2347 insertions, 0 deletions

diff --git a/props.lv2/CMakeLists.txt b/props.lv2/CMakeLists.txt
new file mode 100644
index 0000000..2fff6f0
--- /dev/null
+++ b/props.lv2/CMakeLists.txt
@@ -0,0 +1,41 @@
+cmake_minimum_required(VERSION 2.8)
+
+project(props.lv2)
+
+include_directories(${PROJECT_SOURCE_DIR})
+include_directories(${PROJECT_BINARY_DIR})
+
+set(CMAKE_C_FLAGS "-std=gnu99 -Wextra -Wno-unused-parameter -ffast-math -fvisibility=hidden ${CMAKE_C_FLAGS}")
+set(CMAKE_C_FLAGS "-Wshadow -Wimplicit-function-declaration -Wredundant-decls -Wmissing-prototypes -Wstrict-prototypes ${CMAKE_C_FLAGS}")
+set(CMAKE_MODULE_LINKER_FLAGS "-Wl,-z,nodelete ${CMAKE_MODULE_LINKER_FLAGS}")
+add_definitions("-D_GNU_SOURCE=1") # asprintf
+
+set(PROPS_MAJOR_VERSION 0)
+set(PROPS_MINOR_VERSION 1)
+set(PROPS_MICRO_VERSION 1)
+set(PROPS_VERSION "${PROPS_MAJOR_VERSION}.${PROPS_MINOR_VERSION}.${PROPS_MICRO_VERSION}")
+add_definitions("-DPROPS_VERSION=\"${PROPS_VERSION}\"")
+
+set(DEST lib/lv2/props.lv2)
+if(WIN32)
+	set(LIB_EXT ".dll")
+elseif(APPLE)
+	set(LIB_EXT ".so")
+else()
+	set(LIB_EXT ".so")
+endif()
+
+find_package(PkgConfig) # ${PKG_CONFIG_FOUND}
+
+# props
+add_library(props MODULE
+	test/props.c)
+target_link_libraries(props ${LIBS})
+set_target_properties(props PROPERTIES PREFIX "")
+install(TARGETS props DESTINATION ${DEST})
+install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/test/props.ttl DESTINATION ${DEST})
+install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/test/chunk.bin DESTINATION ${DEST})
+
+# manifest
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/test/manifest.ttl.in ${PROJECT_BINARY_DIR}/manifest.ttl)
+install(FILES ${PROJECT_BINARY_DIR}/manifest.ttl DESTINATION ${DEST})
diff --git a/props.lv2/COPYING b/props.lv2/COPYING
new file mode 100644
index 0000000..ddb9a46
--- /dev/null
+++ b/props.lv2/COPYING
@@ -0,0 +1,201 @@
+		       The Artistic License 2.0
+
+	    Copyright (c) 2000-2006, The Perl Foundation.
+
+     Everyone is permitted to copy and distribute verbatim copies
+      of this license document, but changing it is not allowed.
+
+Preamble
+
+This license establishes the terms under which a given free software
+Package may be copied, modified, distributed, and/or redistributed.
+The intent is that the Copyright Holder maintains some artistic
+control over the development of that Package while still keeping the
+Package available as open source and free software.
+
+You are always permitted to make arrangements wholly outside of this
+license directly with the Copyright Holder of a given Package.  If the
+terms of this license do not permit the full use that you propose to
+make of the Package, you should contact the Copyright Holder and seek
+a different licensing arrangement. 
+
+Definitions
+
+    "Copyright Holder" means the individual(s) or organization(s)
+    named in the copyright notice for the entire Package.
+
+    "Contributor" means any party that has contributed code or other
+    material to the Package, in accordance with the Copyright Holder's
+    procedures.
+
+    "You" and "your" means any person who would like to copy,
+    distribute, or modify the Package.
+
+    "Package" means the collection of files distributed by the
+    Copyright Holder, and derivatives of that collection and/or of
+    those files. A given Package may consist of either the Standard
+    Version, or a Modified Version.
+
+    "Distribute" means providing a copy of the Package or making it
+    accessible to anyone else, or in the case of a company or
+    organization, to others outside of your company or organization.
+
+    "Distributor Fee" means any fee that you charge for Distributing
+    this Package or providing support for this Package to another
+    party.  It does not mean licensing fees.
+
+    "Standard Version" refers to the Package if it has not been
+    modified, or has been modified only in ways explicitly requested
+    by the Copyright Holder.
+
+    "Modified Version" means the Package, if it has been changed, and
+    such changes were not explicitly requested by the Copyright
+    Holder. 
+
+    "Original License" means this Artistic License as Distributed with
+    the Standard Version of the Package, in its current version or as
+    it may be modified by The Perl Foundation in the future.
+
+    "Source" form means the source code, documentation source, and
+    configuration files for the Package.
+
+    "Compiled" form means the compiled bytecode, object code, binary,
+    or any other form resulting from mechanical transformation or
+    translation of the Source form.
+
+
+Permission for Use and Modification Without Distribution
+
+(1)  You are permitted to use the Standard Version and create and use
+Modified Versions for any purpose without restriction, provided that
+you do not Distribute the Modified Version.
+
+
+Permissions for Redistribution of the Standard Version
+
+(2)  You may Distribute verbatim copies of the Source form of the
+Standard Version of this Package in any medium without restriction,
+either gratis or for a Distributor Fee, provided that you duplicate
+all of the original copyright notices and associated disclaimers.  At
+your discretion, such verbatim copies may or may not include a
+Compiled form of the Package.
+
+(3)  You may apply any bug fixes, portability changes, and other
+modifications made available from the Copyright Holder.  The resulting
+Package will still be considered the Standard Version, and as such
+will be subject to the Original License.
+
+
+Distribution of Modified Versions of the Package as Source 
+
+(4)  You may Distribute your Modified Version as Source (either gratis
+or for a Distributor Fee, and with or without a Compiled form of the
+Modified Version) provided that you clearly document how it differs
+from the Standard Version, including, but not limited to, documenting
+any non-standard features, executables, or modules, and provided that
+you do at least ONE of the following:
+
+    (a)  make the Modified Version available to the Copyright Holder
+    of the Standard Version, under the Original License, so that the
+    Copyright Holder may include your modifications in the Standard
+    Version.
+
+    (b)  ensure that installation of your Modified Version does not
+    prevent the user installing or running the Standard Version. In
+    addition, the Modified Version must bear a name that is different
+    from the name of the Standard Version.
+
+    (c)  allow anyone who receives a copy of the Modified Version to
+    make the Source form of the Modified Version available to others
+    under
+		
+	(i)  the Original License or
+
+	(ii)  a license that permits the licensee to freely copy,
+	modify and redistribute the Modified Version using the same
+	licensing terms that apply to the copy that the licensee
+	received, and requires that the Source form of the Modified
+	Version, and of any works derived from it, be made freely
+	available in that license fees are prohibited but Distributor
+	Fees are allowed.
+
+
+Distribution of Compiled Forms of the Standard Version 
+or Modified Versions without the Source
+
+(5)  You may Distribute Compiled forms of the Standard Version without
+the Source, provided that you include complete instructions on how to
+get the Source of the Standard Version.  Such instructions must be
+valid at the time of your distribution.  If these instructions, at any
+time while you are carrying out such distribution, become invalid, you
+must provide new instructions on demand or cease further distribution.
+If you provide valid instructions or cease distribution within thirty
+days after you become aware that the instructions are invalid, then
+you do not forfeit any of your rights under this license.
+
+(6)  You may Distribute a Modified Version in Compiled form without
+the Source, provided that you comply with Section 4 with respect to
+the Source of the Modified Version.
+
+
+Aggregating or Linking the Package 
+
+(7)  You may aggregate the Package (either the Standard Version or
+Modified Version) with other packages and Distribute the resulting
+aggregation provided that you do not charge a licensing fee for the
+Package.  Distributor Fees are permitted, and licensing fees for other
+components in the aggregation are permitted. The terms of this license
+apply to the use and Distribution of the Standard or Modified Versions
+as included in the aggregation.
+
+(8) You are permitted to link Modified and Standard Versions with
+other works, to embed the Package in a larger work of your own, or to
+build stand-alone binary or bytecode versions of applications that
+include the Package, and Distribute the result without restriction,
+provided the result does not expose a direct interface to the Package.
+
+
+Items That are Not Considered Part of a Modified Version 
+
+(9) Works (including, but not limited to, modules and scripts) that
+merely extend or make use of the Package, do not, by themselves, cause
+the Package to be a Modified Version.  In addition, such works are not
+considered parts of the Package itself, and are not subject to the
+terms of this license.
+
+
+General Provisions
+
+(10)  Any use, modification, and distribution of the Standard or
+Modified Versions is governed by this Artistic License. By using,
+modifying or distributing the Package, you accept this license. Do not
+use, modify, or distribute the Package, if you do not accept this
+license.
+
+(11)  If your Modified Version has been derived from a Modified
+Version made by someone other than you, you are nevertheless required
+to ensure that your Modified Version complies with the requirements of
+this license.
+
+(12)  This license does not grant you the right to use any trademark,
+service mark, tradename, or logo of the Copyright Holder.
+
+(13)  This license includes the non-exclusive, worldwide,
+free-of-charge patent license to make, have made, use, offer to sell,
+sell, import and otherwise transfer the Package with respect to any
+patent claims licensable by the Copyright Holder that are necessarily
+infringed by the Package. If you institute patent litigation
+(including a cross-claim or counterclaim) against any party alleging
+that the Package constitutes direct or contributory patent
+infringement, then this Artistic License to you shall terminate on the
+date that such litigation is filed.
+
+(14)  Disclaimer of Warranty:
+THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS
+IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES. THE IMPLIED
+WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
+NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY YOUR LOCAL
+LAW. UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR CONTRIBUTOR WILL
+BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THE PACKAGE, EVEN IF
+ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/props.lv2/README.md b/props.lv2/README.md
new file mode 100644
index 0000000..08466d2
--- /dev/null
+++ b/props.lv2/README.md
@@ -0,0 +1,20 @@
+# Props.lv2
+
+## Utility header for property based LV2 plugins
+
+### License
+
+Copyright (c) 2015 Hanspeter Portner (dev@open-music-kontrollers.ch)
+
+This is free software: you can redistribute it and/or modify
+it under the terms of the Artistic License 2.0 as published by
+The Perl Foundation.
+
+This source 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
+Artistic License 2.0 for more details.
+
+You should have received a copy of the Artistic License 2.0
+along the source as a COPYING file. If not, obtain it from
+<http://www.perlfoundation.org/artistic_license_2_0>.
diff --git a/props.lv2/props.h b/props.lv2/props.h
new file mode 100644
index 0000000..ebbc3ec
--- /dev/null
+++ b/props.lv2/props.h
@@ -0,0 +1,1325 @@
+/*
+ * Copyright (c) 2015 Hanspeter Portner (dev@open-music-kontrollers.ch)
+ *
+ * This is free software: you can redistribute it and/or modify
+ * it under the terms of the Artistic License 2.0 as published by
+ * The Perl Foundation.
+ *
+ * This source 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
+ * Artistic License 2.0 for more details.
+ *
+ * You should have received a copy of the Artistic License 2.0
+ * along the source as a COPYING file. If not, obtain it from
+ * http://www.perlfoundation.org/artistic_license_2_0.
+ */
+
+#ifndef _LV2_PROPS_H_
+#define _LV2_PROPS_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdlib.h>
+#include <stdatomic.h>
+
+#include <lv2/lv2plug.in/ns/lv2core/lv2.h>
+#include <lv2/lv2plug.in/ns/ext/urid/urid.h>
+#include <lv2/lv2plug.in/ns/ext/atom/atom.h>
+#include <lv2/lv2plug.in/ns/ext/atom/forge.h>
+#include <lv2/lv2plug.in/ns/ext/patch/patch.h>
+#include <lv2/lv2plug.in/ns/ext/state/state.h>
+#include <lv2/lv2plug.in/ns/extensions/units/units.h>
+
+/*****************************************************************************
+ * API START
+ *****************************************************************************/
+
+// definitions
+#define PROPS_TYPE_N 10
+
+// unions
+typedef union _props_raw_t props_raw_t;
+
+// enumerations
+typedef enum _props_mode_t props_mode_t;
+typedef enum _props_event_t props_event_t;
+
+// structures
+typedef struct _props_scale_point_t props_scale_point_t;
+typedef struct _props_def_t props_def_t;
+typedef struct _props_type_t props_type_t;
+typedef struct _props_impl_t props_impl_t;
+typedef struct _props_t props_t;
+
+// function callbacks
+typedef void (*props_event_cb_t)(
+	void *data,
+	LV2_Atom_Forge *forge,
+	int64_t frames,
+	props_event_t event,
+	props_impl_t *impl);
+
+typedef uint32_t (*props_type_size_cb_t)(
+	const void *value);
+
+typedef LV2_Atom_Forge_Ref (*props_type_get_cb_t)(
+	LV2_Atom_Forge *forge,
+	const void *value);
+
+typedef void (*props_type_set_cb_t)(
+	props_impl_t *impl,
+	void *value,
+	LV2_URID new_type,
+	uint32_t sz,
+	const void *new_value);
+
+union _props_raw_t {
+	const int32_t i;			// Int
+	const int64_t h;			// Long
+	const float f;				// Float
+	const double d;				// Double
+	const int32_t b;			// Bool
+	const uint32_t u;			// URID
+	//TODO more types
+};
+
+enum _props_mode_t {
+	PROP_MODE_STATIC			= 0,
+	PROP_MODE_DYNAMIC			= 1
+};
+
+enum _props_event_t {
+	PROP_EVENT_GET				= (1 << 0),
+	PROP_EVENT_SET				= (1 << 1),
+	PROP_EVENT_SAVE				= (1 << 2),
+	PROP_EVENT_RESTORE		= (1 << 3),
+	PROP_EVENT_REGISTER		= (1 << 4)
+};
+
+#define PROP_EVENT_NONE		(0)
+#define PROP_EVENT_READ		(PROP_EVENT_GET		| PROP_EVENT_SAVE)
+#define PROP_EVENT_WRITE	(PROP_EVENT_SET		| PROP_EVENT_RESTORE)
+#define PROP_EVENT_RW			(PROP_EVENT_READ	| PROP_EVENT_WRITE)
+#define PROP_EVENT_ALL		(PROP_EVENT_RW		| PROP_EVENT_REGISTER)
+
+struct _props_scale_point_t {
+	const char *label;
+	props_raw_t value;
+};
+
+struct _props_def_t {
+	const char *property;
+	const char *type;
+	const char *access;
+	const char *unit;
+	props_mode_t mode;
+	props_event_t event_mask;
+	props_event_cb_t event_cb;
+	uint32_t max_size;
+
+	const char *label;
+	const char *comment;
+	props_raw_t minimum;
+	props_raw_t maximum;
+	const props_scale_point_t *scale_points;
+};
+
+struct _props_type_t {
+	LV2_URID urid;
+	uint32_t size;
+	props_type_size_cb_t size_cb;
+	props_type_get_cb_t get_cb;
+	props_type_set_cb_t set_cb;
+};
+
+struct _props_impl_t {
+	LV2_URID property;
+	LV2_URID access;
+	LV2_URID unit;
+	const props_t *props;
+	const props_type_t *type;
+	const props_def_t *def;
+	void *value;
+	void *stash;
+	atomic_flag lock;
+	bool stashing;
+};
+
+struct _props_t {
+	struct {
+		LV2_URID subject;
+
+		LV2_URID patch_get;
+		LV2_URID patch_set;
+		LV2_URID patch_put;
+		LV2_URID patch_patch;
+		LV2_URID patch_wildcard;
+		LV2_URID patch_add;
+		LV2_URID patch_remove;
+		LV2_URID patch_subject;
+		LV2_URID patch_body;
+		LV2_URID patch_property;
+		LV2_URID patch_value;
+		LV2_URID patch_writable;
+		LV2_URID patch_readable;
+
+		LV2_URID rdf_value;
+
+		LV2_URID rdfs_label;
+		LV2_URID rdfs_range;
+		LV2_URID rdfs_comment;
+
+		LV2_URID lv2_minimum;
+		LV2_URID lv2_maximum;
+		LV2_URID lv2_scale_point;
+
+		LV2_URID atom_int;
+		LV2_URID atom_long;
+		LV2_URID atom_float;
+		LV2_URID atom_double;
+		LV2_URID atom_bool;
+		LV2_URID atom_urid;
+		LV2_URID atom_string;
+		LV2_URID atom_path;
+		LV2_URID atom_uri;
+		LV2_URID atom_chunk;
+
+		LV2_URID units_unit;
+	} urid;
+
+	LV2_URID_Map *map;
+	void *data;
+
+	props_type_t types [PROPS_TYPE_N];
+
+	bool stashing;
+
+	unsigned max_size;
+	unsigned max_nimpls;
+	unsigned nimpls;
+	props_impl_t impls [0];
+};
+
+#define PROPS_T(PROPS, MAX_NIMPLS) \
+	props_t (PROPS); \
+	props_impl_t _impls [(MAX_NIMPLS)];
+
+// rt-safe
+static inline int
+props_init(props_t *props, const size_t max_nimpls, const char *subject,
+	LV2_URID_Map *map, void *data);
+
+// rt-safe
+static inline LV2_URID
+props_register(props_t *props, const props_def_t *def, void *value, void *stash);
+
+// rt-safe
+static inline int
+props_advance(props_t *props, LV2_Atom_Forge *forge, uint32_t frames,
+	const LV2_Atom_Object *obj, LV2_Atom_Forge_Ref *ref);
+
+// rt-safe
+static inline void
+props_set(props_t *props, LV2_Atom_Forge *forge, uint32_t frames, LV2_URID property,
+	LV2_Atom_Forge_Ref *ref);
+
+// rt-safe
+static inline void
+props_stash(props_t *props, LV2_URID property);
+
+// non-rt
+static inline LV2_State_Status
+props_save(props_t *props, LV2_Atom_Forge *forge, LV2_State_Store_Function store,
+	LV2_State_Handle state, uint32_t flags, const LV2_Feature *const *features);
+
+// non-rt
+static inline LV2_State_Status
+props_restore(props_t *props, LV2_Atom_Forge *forge, LV2_State_Retrieve_Function retrieve,
+	LV2_State_Handle state, uint32_t flags, const LV2_Feature *const *features);
+
+/*****************************************************************************
+ * API END
+ *****************************************************************************/
+
+static inline void
+_impl_spin_lock(props_impl_t *impl)
+{
+	while(atomic_flag_test_and_set_explicit(&impl->lock, memory_order_acquire))
+	{
+		// spin
+	}
+}
+
+static inline bool
+_impl_try_lock(props_impl_t *impl)
+{
+	return atomic_flag_test_and_set_explicit(&impl->lock, memory_order_acquire) == false;
+}
+
+static inline void
+_impl_unlock(props_impl_t *impl)
+{
+	atomic_flag_clear_explicit(&impl->lock, memory_order_release);
+}
+
+static inline uint32_t
+_impl_size_get(props_impl_t *impl)
+{
+	return impl->type->size_cb
+		? impl->type->size_cb(impl->value)
+		: impl->type->size;
+}
+
+static LV2_Atom_Forge_Ref
+_props_int_get_cb(LV2_Atom_Forge *forge, const void *value)
+{
+	return lv2_atom_forge_int(forge, *(const int32_t *)value);
+}
+static LV2_Atom_Forge_Ref
+_props_bool_get_cb(LV2_Atom_Forge *forge, const void *value)
+{
+	return lv2_atom_forge_bool(forge, *(const int32_t *)value);
+}
+static void
+_props_int_set_cb(props_impl_t *impl, void *value,
+	LV2_URID new_type, uint32_t sz, const void *new_value)
+{
+	const props_t *props = impl->props;
+	int32_t *ref = value;
+
+	if(new_type == props->urid.atom_int)
+		*ref = *(const int32_t *)new_value;
+	else if(new_type == props->urid.atom_bool)
+		*ref = *(const int32_t *)new_value;
+	else if(new_type == props->urid.atom_urid)
+		*ref = *(const uint32_t *)new_value;
+	else if(new_type == props->urid.atom_long)
+		*ref = *(const int64_t *)new_value;
+
+	else if(new_type == props->urid.atom_float)
+		*ref = *(const float *)new_value;
+	else if(new_type == props->urid.atom_double)
+		*ref = *(const double *)new_value;
+}
+
+static LV2_Atom_Forge_Ref
+_props_long_get_cb(LV2_Atom_Forge *forge, const void *value)
+{
+	return lv2_atom_forge_long(forge, *(const int64_t *)value);
+}
+static void
+_props_long_set_cb(props_impl_t *impl, void *value,
+	LV2_URID new_type, uint32_t sz, const void *new_value)
+{
+	const props_t *props = impl->props;
+	int64_t *ref = value;
+
+	if(new_type == props->urid.atom_long)
+		*ref = *(const int64_t *)new_value;
+	else if(new_type == props->urid.atom_int)
+		*ref = *(const int32_t *)new_value;
+	else if(new_type == props->urid.atom_bool)
+		*ref = *(const int32_t *)new_value;
+	else if(new_type == props->urid.atom_urid)
+		*ref = *(const uint32_t *)new_value;
+
+	else if(new_type == props->urid.atom_float)
+		*ref = *(const float *)new_value;
+	else if(new_type == props->urid.atom_double)
+		*ref = *(const double *)new_value;
+}
+
+static LV2_Atom_Forge_Ref
+_props_float_get_cb(LV2_Atom_Forge *forge, const void *value)
+{
+	return lv2_atom_forge_float(forge, *(const float *)value);
+}
+static void
+_props_float_set_cb(props_impl_t *impl, void *value,
+	LV2_URID new_type, uint32_t sz, const void *new_value)
+{
+	const props_t *props = impl->props;
+	float *ref = value;
+
+	if(new_type == props->urid.atom_float)
+		*ref = *(const float *)new_value;
+	else if(new_type == props->urid.atom_double)
+		*ref = *(const double *)new_value;
+
+	else if(new_type == props->urid.atom_int)
+		*ref = *(const int32_t *)new_value;
+	else if(new_type == props->urid.atom_bool)
+		*ref = *(const int32_t *)new_value;
+	else if(new_type == props->urid.atom_urid)
+		*ref = *(const uint32_t *)new_value;
+	else if(new_type == props->urid.atom_long)
+		*ref = *(const int64_t *)new_value;
+}
+
+static LV2_Atom_Forge_Ref
+_props_double_get_cb(LV2_Atom_Forge *forge, const void *value)
+{
+	return lv2_atom_forge_double(forge, *(const double *)value);
+}
+static void
+_props_double_set_cb(props_impl_t *impl, void *value,
+	LV2_URID new_type, uint32_t sz, const void *new_value)
+{
+	const props_t *props = impl->props;
+	double *ref = value;
+
+	if(new_type == props->urid.atom_double)
+		*ref = *(const double *)new_value;
+	else if(new_type == props->urid.atom_float)
+		*ref = *(const float *)new_value;
+
+	else if(new_type == props->urid.atom_int)
+		*ref = *(const int32_t *)new_value;
+	else if(new_type == props->urid.atom_bool)
+		*ref = *(const int32_t *)new_value;
+	else if(new_type == props->urid.atom_urid)
+		*ref = *(const uint32_t *)new_value;
+	else if(new_type == props->urid.atom_long)
+		*ref = *(const int64_t *)new_value;
+}
+
+static LV2_Atom_Forge_Ref
+_props_urid_get_cb(LV2_Atom_Forge *forge, const void *value)
+{
+	return lv2_atom_forge_urid(forge, *(const uint32_t *)value);
+}
+static void
+_props_urid_set_cb(props_impl_t *impl, void *value,
+	LV2_URID new_type, uint32_t sz, const void *new_value)
+{
+	const props_t *props = impl->props;
+	uint32_t *ref = value;
+
+	if(new_type == props->urid.atom_urid)
+		*ref = *(const uint32_t *)new_value;
+
+	else if(new_type == props->urid.atom_int)
+		*ref = *(const int32_t *)new_value;
+	else if(new_type == props->urid.atom_long)
+		*ref = *(const int64_t *)new_value;
+	else if(new_type == props->urid.atom_bool)
+		*ref = *(const int32_t *)new_value;
+	else if(new_type == props->urid.atom_float)
+		*ref = *(const float *)new_value;
+	else if(new_type == props->urid.atom_double)
+		*ref = *(const double *)new_value;
+}
+
+static uint32_t
+_props_string_size_cb(const void *value)
+{
+	return strlen((const char *)value) + 1;
+}
+static LV2_Atom_Forge_Ref
+_props_string_get_cb(LV2_Atom_Forge *forge, const void *value)
+{
+	return lv2_atom_forge_string(forge, (const char *)value, strlen((const char *)value));
+}
+static LV2_Atom_Forge_Ref
+_props_path_get_cb(LV2_Atom_Forge *forge, const void *value)
+{
+	return lv2_atom_forge_path(forge, (const char *)value, strlen((const char *)value));
+}
+static LV2_Atom_Forge_Ref
+_props_uri_get_cb(LV2_Atom_Forge *forge, const void *value)
+{
+	return lv2_atom_forge_uri(forge, (const char *)value, strlen((const char *)value));
+}
+static void
+_props_string_set_cb(props_impl_t *impl, void *value,
+	LV2_URID new_type, uint32_t sz, const void *new_value)
+{
+	const props_t *props = impl->props;
+
+	if(  (new_type == props->urid.atom_string)
+		|| (new_type == props->urid.atom_path)
+		|| (new_type == props->urid.atom_uri) )
+		strncpy((char *)value, (const char *)new_value, impl->def->max_size);
+}
+
+static uint32_t
+_props_chunk_size_cb(const void *value)
+{
+	const uint32_t sz = *(uint32_t *)value;
+	return sz;
+}
+static LV2_Atom_Forge_Ref
+_props_chunk_get_cb(LV2_Atom_Forge *forge, const void *value)
+{
+	const uint32_t sz = *(uint32_t *)value;
+	const uint8_t *src = value + sizeof(uint32_t);
+	LV2_Atom_Forge_Ref ref;
+
+	return (ref = lv2_atom_forge_atom(forge, sz, forge->Chunk))
+		&& (ref = lv2_atom_forge_write(forge, src, sz));
+}
+static void
+_props_chunk_set_cb(props_impl_t *impl, void *value,
+	LV2_URID new_type, uint32_t sz, const void *new_value)
+{
+	const props_t *props = impl->props;
+
+	if(new_type == props->urid.atom_chunk)
+	{
+		*(uint32_t *)value = sz; // set chunk size
+		uint8_t *dst = value + sizeof(uint32_t);
+		const uint32_t msz = sz < impl->def->max_size - sizeof(uint32_t)
+			? sz
+			: impl->def->max_size - sizeof(uint32_t);
+		memcpy(dst, new_value, msz);
+	}
+}
+
+static inline void
+_type_qsort(props_type_t *a, unsigned n)
+{
+	if(n < 2)
+		return;
+
+	const props_type_t *p = &a[n/2];
+
+	unsigned i, j;
+	for(i=0, j=n-1; ; i++, j--)
+	{
+		while(a[i].urid < p->urid)
+			i++;
+
+		while(p->urid < a[j].urid)
+			j--;
+
+		if(i >= j)
+			break;
+
+		const props_type_t t = a[i];
+		a[i] = a[j];
+		a[j] = t;
+	}
+
+	_type_qsort(a, i);
+	_type_qsort(&a[i], n - i);
+}
+
+static inline props_type_t *
+_type_bsearch(LV2_URID p, props_type_t *a, unsigned n)
+{
+	unsigned start = 0;
+	unsigned end = n;
+
+	while(start < end)
+	{
+		const unsigned mid = start + (end - start)/2;
+		props_type_t *dst = &a[mid];
+
+		if(p < dst->urid)
+			end = mid;
+		else if(p > dst->urid)
+			start = mid + 1;
+		else
+			return dst;
+	}
+
+	return NULL;
+}
+
+static inline void
+_impl_qsort(props_impl_t *a, unsigned n)
+{
+	if(n < 2)
+		return;
+
+	const props_impl_t *p = &a[n/2];
+
+	unsigned i, j;
+	for(i=0, j=n-1; ; i++, j--)
+	{
+		while(a[i].property < p->property)
+			i++;
+
+		while(p->property < a[j].property)
+			j--;
+
+		if(i >= j)
+			break;
+
+		const props_impl_t t = a[i];
+		a[i] = a[j];
+		a[j] = t;
+	}
+
+	_impl_qsort(a, i);
+	_impl_qsort(&a[i], n - i);
+}
+
+static inline props_impl_t *
+_impl_bsearch(LV2_URID p, props_impl_t *a, unsigned n)
+{
+	unsigned start = 0;
+	unsigned end = n;
+
+	while(start < end)
+	{
+		const unsigned mid = start + (end - start)/2;
+		props_impl_t *dst = &a[mid];
+
+		if(p < dst->property)
+			end = mid;
+		else if(p > dst->property)
+			start = mid + 1;
+		else
+			return dst;
+	}
+
+	return NULL;
+}
+
+static inline props_impl_t *
+_props_impl_search(props_t *props, LV2_URID property)
+{
+	return _impl_bsearch(property, props->impls, props->nimpls);
+}
+
+static inline LV2_Atom_Forge_Ref
+_props_get(props_t *props, LV2_Atom_Forge *forge, uint32_t frames, props_impl_t *impl)
+{
+	LV2_Atom_Forge_Frame obj_frame;
+
+	LV2_Atom_Forge_Ref ref = lv2_atom_forge_frame_time(forge, frames);
+
+	if(ref)
+		ref = lv2_atom_forge_object(forge, &obj_frame, 0, props->urid.patch_set);
+	{
+		if(props->urid.subject) // is optional
+		{
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.patch_subject);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, props->urid.subject);
+		}
+
+		if(ref)
+			ref = lv2_atom_forge_key(forge, props->urid.patch_property);
+		if(ref)
+			ref = lv2_atom_forge_urid(forge, impl->property);
+
+		if(ref)
+			lv2_atom_forge_key(forge, props->urid.patch_value);
+		if(ref)
+			ref = impl->type->get_cb(forge, impl->value);
+	}
+	if(ref)
+		lv2_atom_forge_pop(forge, &obj_frame);
+
+	return ref;
+}
+
+static inline void
+_props_stash(props_t *props, props_impl_t *impl)
+{
+	if(_impl_try_lock(impl))
+	{
+		const uint32_t size = _impl_size_get(impl);
+		memcpy(impl->stash, impl->value, size);
+
+		_impl_unlock(impl);
+	}
+	else
+	{
+		impl->stashing = true;
+		props->stashing= true;
+	}
+}
+
+static inline void
+_props_set(props_t *props, props_impl_t *impl, LV2_URID type, uint32_t sz, const void *value)
+{
+	impl->type->set_cb(impl, impl->value, type, sz, value);
+	_props_stash(props, impl);
+}
+
+static inline LV2_Atom_Forge_Ref
+_props_reg(props_t *props, LV2_Atom_Forge *forge, uint32_t frames, props_impl_t *impl)
+{
+	const props_def_t *def = impl->def;
+	LV2_Atom_Forge_Frame obj_frame;
+	LV2_Atom_Forge_Frame add_frame;
+	LV2_Atom_Forge_Frame remove_frame;
+
+	LV2_Atom_Forge_Ref ref = lv2_atom_forge_frame_time(forge, frames);
+	if(ref)
+		ref = lv2_atom_forge_object(forge, &obj_frame, 0, props->urid.patch_patch);
+	{
+		if(props->urid.subject) // is optional
+		{
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.patch_subject);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, props->urid.subject);
+		}
+
+		if(ref)
+			ref = lv2_atom_forge_key(forge, props->urid.patch_remove);
+		if(ref)
+			ref = lv2_atom_forge_object(forge, &remove_frame, 0, 0);
+		{
+			if(ref)
+				ref = lv2_atom_forge_key(forge, impl->access);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, impl->property);
+		}
+		if(ref)
+			lv2_atom_forge_pop(forge, &remove_frame);
+
+		if(ref)
+			ref = lv2_atom_forge_key(forge, props->urid.patch_add);
+		if(ref)
+			ref = lv2_atom_forge_object(forge, &add_frame, 0, 0);
+		{
+			if(ref)
+				ref = lv2_atom_forge_key(forge, impl->access);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, impl->property);
+		}
+		if(ref)
+			lv2_atom_forge_pop(forge, &add_frame);
+	}
+	if(ref)
+		lv2_atom_forge_pop(forge, &obj_frame);
+
+	if(ref)
+		ref = lv2_atom_forge_frame_time(forge, frames);
+	if(ref)
+		ref = lv2_atom_forge_object(forge, &obj_frame, 0, props->urid.patch_patch);
+	{
+		if(ref)
+			ref = lv2_atom_forge_key(forge, props->urid.patch_subject);
+		if(ref)
+			ref = lv2_atom_forge_urid(forge, impl->property);
+
+		if(ref)
+			ref = lv2_atom_forge_key(forge, props->urid.patch_remove);
+		if(ref)
+			ref = lv2_atom_forge_object(forge, &remove_frame, 0, 0);
+		{
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.rdfs_range);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, props->urid.patch_wildcard);
+
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.rdfs_label);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, props->urid.patch_wildcard);
+
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.rdfs_comment);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, props->urid.patch_wildcard);
+
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.lv2_minimum);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, props->urid.patch_wildcard);
+
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.lv2_maximum);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, props->urid.patch_wildcard);
+
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.units_unit);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, props->urid.patch_wildcard);
+
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.lv2_scale_point);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, props->urid.patch_wildcard);
+		}
+		if(ref)
+			lv2_atom_forge_pop(forge, &remove_frame);
+
+		if(ref)
+			ref = lv2_atom_forge_key(forge, props->urid.patch_add);
+		if(ref)
+			ref = lv2_atom_forge_object(forge, &add_frame, 0, 0);
+		{
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.rdfs_range);
+			if(ref)
+				ref = lv2_atom_forge_urid(forge, impl->type->urid);
+
+			if(def->label)
+			{
+				if(ref)
+					ref = lv2_atom_forge_key(forge, props->urid.rdfs_label);
+				if(ref)
+					ref = lv2_atom_forge_string(forge, def->label, strlen(def->label));
+			}
+
+			if(def->comment)
+			{
+				if(ref)
+					ref = lv2_atom_forge_key(forge, props->urid.rdfs_comment);
+				if(ref)
+					ref = lv2_atom_forge_string(forge, def->comment, strlen(def->comment));
+			}
+
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.lv2_minimum);
+			if(ref)
+				ref = impl->type->get_cb(forge, &def->minimum);
+
+			if(ref)
+				ref = lv2_atom_forge_key(forge, props->urid.lv2_maximum);
+			if(ref)
+				ref = impl->type->get_cb(forge, &def->maximum);
+
+			if(props->urid.units_unit)
+			{
+				if(ref)
+					ref = lv2_atom_forge_key(forge, props->urid.units_unit);
+				if(ref)
+					ref = lv2_atom_forge_urid(forge, impl->unit);
+			}
+
+			if(def->scale_points)
+			{
+				for(const props_scale_point_t *sp = def->scale_points; sp->label; sp++)
+				{
+					LV2_Atom_Forge_Frame scale_point_frame;
+
+					if(ref)
+						ref = lv2_atom_forge_key(forge, props->urid.lv2_scale_point);
+					if(ref)
+						ref = lv2_atom_forge_object(forge, &scale_point_frame, 0, 0);
+					{
+						if(ref)
+							ref = lv2_atom_forge_key(forge, props->urid.rdfs_label);
+						if(ref)
+							ref = lv2_atom_forge_string(forge, sp->label, strlen(sp->label));
+
+						if(ref)
+							ref = lv2_atom_forge_key(forge, props->urid.rdf_value);
+						if(ref)
+							ref = impl->type->get_cb(forge, &sp->value);
+					}
+					if(ref)
+						lv2_atom_forge_pop(forge, &scale_point_frame);
+				}
+			}
+		}
+		if(ref)
+			lv2_atom_forge_pop(forge, &add_frame);
+	}
+	if(ref)
+		lv2_atom_forge_pop(forge, &obj_frame);
+
+	return ref;
+}
+
+static inline int
+props_init(props_t *props, const size_t max_nimpls, const char *subject,
+	LV2_URID_Map *map, void *data)
+{
+	if(!map)
+		return 0;
+
+	props->nimpls = 0;
+	props->max_nimpls = max_nimpls;
+	props->map = map;
+	props->data = data;
+
+	props->urid.subject = subject ? map->map(map->handle, subject) : 0;
+
+	props->urid.patch_get = map->map(map->handle, LV2_PATCH__Get);
+	props->urid.patch_set = map->map(map->handle, LV2_PATCH__Set);
+	props->urid.patch_put = map->map(map->handle, LV2_PATCH__Put);
+	props->urid.patch_patch = map->map(map->handle, LV2_PATCH__Patch);
+	props->urid.patch_wildcard = map->map(map->handle, LV2_PATCH__wildcard);
+	props->urid.patch_add = map->map(map->handle, LV2_PATCH__add);
+	props->urid.patch_remove = map->map(map->handle, LV2_PATCH__remove);
+	props->urid.patch_subject = map->map(map->handle, LV2_PATCH__subject);
+	props->urid.patch_body = map->map(map->handle, LV2_PATCH__body);
+	props->urid.patch_property = map->map(map->handle, LV2_PATCH__property);
+	props->urid.patch_value = map->map(map->handle, LV2_PATCH__value);
+	props->urid.patch_writable = map->map(map->handle, LV2_PATCH__writable);
+	props->urid.patch_readable = map->map(map->handle, LV2_PATCH__readable);
+
+	props->urid.rdf_value = map->map(map->handle,
+		"http://www.w3.org/1999/02/22-rdf-syntax-ns#value");
+
+	props->urid.rdfs_label = map->map(map->handle,
+		"http://www.w3.org/2000/01/rdf-schema#label");
+	props->urid.rdfs_range = map->map(map->handle,
+		"http://www.w3.org/2000/01/rdf-schema#range");
+	props->urid.rdfs_comment = map->map(map->handle,
+		"http://www.w3.org/2000/01/rdf-schema#comment");
+
+	props->urid.lv2_minimum = map->map(map->handle, LV2_CORE__minimum);
+	props->urid.lv2_maximum = map->map(map->handle, LV2_CORE__maximum);
+	props->urid.lv2_scale_point = map->map(map->handle, LV2_CORE__scalePoint);
+
+	props->urid.atom_int = map->map(map->handle, LV2_ATOM__Int);
+	props->urid.atom_long = map->map(map->handle, LV2_ATOM__Long);
+	props->urid.atom_float = map->map(map->handle, LV2_ATOM__Float);
+	props->urid.atom_double = map->map(map->handle, LV2_ATOM__Double);
+	props->urid.atom_bool = map->map(map->handle, LV2_ATOM__Bool);
+	props->urid.atom_urid = map->map(map->handle, LV2_ATOM__URID);
+	props->urid.atom_string = map->map(map->handle, LV2_ATOM__String);
+	props->urid.atom_path = map->map(map->handle, LV2_ATOM__Path);
+	props->urid.atom_uri = map->map(map->handle, LV2_ATOM__URI);
+	props->urid.atom_chunk = map->map(map->handle, LV2_ATOM__Chunk);
+
+	props->urid.units_unit = map->map(map->handle, LV2_UNITS__unit);
+
+	// Int
+	unsigned ptr = 0;
+	props->types[ptr].urid = props->urid.atom_int;
+	props->types[ptr].size = sizeof(int32_t);
+	props->types[ptr].size_cb = NULL;
+	props->types[ptr].get_cb = _props_int_get_cb;
+	props->types[ptr].set_cb = _props_int_set_cb;
+	ptr++;
+
+	// Long
+	props->types[ptr].urid = props->urid.atom_long;
+	props->types[ptr].size = sizeof(int64_t);
+	props->types[ptr].size_cb = NULL;
+	props->types[ptr].get_cb = _props_long_get_cb;
+	props->types[ptr].set_cb = _props_long_set_cb;
+	ptr++;
+
+	// Float
+	props->types[ptr].urid = props->urid.atom_float;
+	props->types[ptr].size = sizeof(float);
+	props->types[ptr].size_cb = NULL;
+	props->types[ptr].get_cb = _props_float_get_cb;
+	props->types[ptr].set_cb = _props_float_set_cb;
+	ptr++;
+
+	// double
+	props->types[ptr].urid = props->urid.atom_double;
+	props->types[ptr].size = sizeof(double);
+	props->types[ptr].size_cb = NULL;
+	props->types[ptr].get_cb = _props_double_get_cb;
+	props->types[ptr].set_cb = _props_double_set_cb;
+	ptr++;
+
+	// Bool
+	props->types[ptr].urid = props->urid.atom_bool;
+	props->types[ptr].size = sizeof(int32_t);
+	props->types[ptr].size_cb = NULL;
+	props->types[ptr].get_cb = _props_bool_get_cb;
+	props->types[ptr].set_cb = _props_int_set_cb;
+	ptr++;
+
+	// URID
+	props->types[ptr].urid = props->urid.atom_urid;
+	props->types[ptr].size = sizeof(uint32_t);
+	props->types[ptr].size_cb = NULL;
+	props->types[ptr].get_cb = _props_urid_get_cb;
+	props->types[ptr].set_cb = _props_urid_set_cb;
+	ptr++;
+
+	// String
+	props->types[ptr].urid = props->urid.atom_string;
+	props->types[ptr].size = 0;
+	props->types[ptr].size_cb = _props_string_size_cb;
+	props->types[ptr].get_cb = _props_string_get_cb;
+	props->types[ptr].set_cb = _props_string_set_cb;
+	ptr++;
+
+	// Path
+	props->types[ptr].urid = props->urid.atom_path;
+	props->types[ptr].size = 0;
+	props->types[ptr].size_cb = _props_string_size_cb;
+	props->types[ptr].get_cb = _props_path_get_cb;
+	props->types[ptr].set_cb = _props_string_set_cb;
+	ptr++;
+
+	// URI
+	props->types[ptr].urid = props->urid.atom_uri;
+	props->types[ptr].size = 0;
+	props->types[ptr].size_cb = _props_string_size_cb;
+	props->types[ptr].get_cb = _props_uri_get_cb;
+	props->types[ptr].set_cb = _props_string_set_cb;
+	ptr++;
+
+	// URI
+	props->types[ptr].urid = props->urid.atom_chunk;
+	props->types[ptr].size = 0;
+	props->types[ptr].size_cb = _props_chunk_size_cb;
+	props->types[ptr].get_cb = _props_chunk_get_cb;
+	props->types[ptr].set_cb = _props_chunk_set_cb;
+	ptr++;
+
+	assert(ptr == PROPS_TYPE_N);
+	_type_qsort(props->types, PROPS_TYPE_N);
+
+	return 1;
+}
+
+static inline LV2_URID
+props_register(props_t *props, const props_def_t *def, void *value, void *stash)
+{
+	if(props->nimpls >= props->max_nimpls)
+		return 0;
+
+	if(!def || !def->property || !def->access || !def->type || !value || !stash)
+		return 0;
+
+	const LV2_URID type = props->map->map(props->map->handle, def->type);
+	const props_type_t *props_type = _type_bsearch(type, props->types, PROPS_TYPE_N);
+	const LV2_URID property = props->map->map(props->map->handle, def->property);
+	const LV2_URID access = props->map->map(props->map->handle, def->access);
+
+	if(!props_type || !property || !access)
+		return 0;
+
+	props_impl_t *impl = &props->impls[props->nimpls++];
+
+	impl->props = props;
+	impl->property = property;
+	impl->access = access;
+	impl->unit = def->unit ? props->map->map(props->map->handle, def->unit) : 0;
+	impl->type = props_type;
+	impl->def = def;
+	impl->value = value;
+	impl->stash = stash;
+	atomic_flag_clear_explicit(&impl->lock, memory_order_relaxed);
+
+	// update maximal value size
+	if(props_type->size && (props_type->size > props->max_size) )
+		props->max_size = props_type->size;
+	else if(def->max_size && (def->max_size > props->max_size) )
+		props->max_size = def->max_size;
+	
+	_impl_qsort(props->impls, props->nimpls);
+
+	//TODO register?
+
+	return property;
+}
+
+static inline int
+props_advance(props_t *props, LV2_Atom_Forge *forge, uint32_t frames,
+	const LV2_Atom_Object *obj, LV2_Atom_Forge_Ref *ref)
+{
+	if(props->stashing)
+	{
+		props->stashing = false;
+
+		for(unsigned i = 0; i < props->nimpls; i++)
+		{
+			props_impl_t *impl = &props->impls[i];
+
+			if(impl->stashing)
+			{
+				impl->stashing= false;
+				_props_stash(props, impl);
+			}
+		}
+	}
+
+	if(!lv2_atom_forge_is_object_type(forge, obj->atom.type))
+		return 0;
+
+	if(obj->body.otype == props->urid.patch_get)
+	{
+		const LV2_Atom_URID *subject = NULL;
+		const LV2_Atom_URID *property = NULL;
+
+		LV2_Atom_Object_Query q [] = {
+			{ props->urid.patch_subject, (const LV2_Atom **)&subject },
+			{ props->urid.patch_property, (const LV2_Atom **)&property },
+			LV2_ATOM_OBJECT_QUERY_END
+		};
+		lv2_atom_object_query(obj, q);
+
+		// check for a matching optional subject
+		if(  (subject && props->urid.subject)
+			&& ( (subject->atom.type != props->urid.atom_urid)
+				|| (subject->body != props->urid.subject) ) )
+		{
+			return 0;
+		}
+
+		if(!property)
+		{
+			for(unsigned i = 0; i < props->nimpls; i++)
+			{
+				props_impl_t *impl = &props->impls[i];
+				const props_def_t *def = impl->def;
+
+				if(impl->def->mode == PROP_MODE_DYNAMIC)
+				{
+					if(*ref)
+						*ref = _props_reg(props, forge, frames, impl);
+					if(def->event_cb && (def->event_mask & PROP_EVENT_REGISTER) )
+						def->event_cb(props->data, forge, frames, PROP_EVENT_REGISTER, impl);
+				}
+
+				if(*ref)
+					*ref = _props_get(props, forge, frames, impl);
+				if(def->event_cb && (def->event_mask & PROP_EVENT_GET) )
+					def->event_cb(props->data, forge, frames, PROP_EVENT_GET, impl);
+			}
+			return 1;
+		}
+		else if(property->atom.type == props->urid.atom_urid)
+		{
+			props_impl_t *impl = _props_impl_search(props, property->body);
+
+			if(impl)
+			{
+				*ref = _props_get(props, forge, frames, impl);
+
+				const props_def_t *def = impl->def;
+				if(def->event_cb && (def->event_mask & PROP_EVENT_GET) )
+					def->event_cb(props->data, forge, frames, PROP_EVENT_GET, impl);
+
+				return 1;
+			}
+		}
+	}
+	else if(obj->body.otype == props->urid.patch_set)
+	{
+		const LV2_Atom_URID *subject = NULL;
+		const LV2_Atom_URID *property = NULL;
+		const LV2_Atom *value = NULL;
+
+		LV2_Atom_Object_Query q [] = {
+			{ props->urid.patch_subject, (const LV2_Atom **)&subject },
+			{ props->urid.patch_property, (const LV2_Atom **)&property },
+			{ props->urid.patch_value, &value },
+			LV2_ATOM_OBJECT_QUERY_END
+		};
+		lv2_atom_object_query(obj, q);
+
+		if(!property || (property->atom.type != props->urid.atom_urid) || !value)
+		{
+			return 0;
+		}
+
+		// check for a matching optional subject
+		if(  (subject && props->urid.subject)
+			&& ( (subject->atom.type != props->urid.atom_urid)
+				|| (subject->body != props->urid.subject) ) )
+		{
+			return 0;
+		}
+
+		props_impl_t *impl = _props_impl_search(props, property->body);
+		if(impl && (impl->access == props->urid.patch_writable) )
+		{
+			_props_set(props, impl, value->type, value->size, LV2_ATOM_BODY_CONST(value));
+
+			const props_def_t *def = impl->def;
+			if(def->event_cb && (def->event_mask & PROP_EVENT_SET) )
+				def->event_cb(props->data, forge, frames, PROP_EVENT_SET, impl);
+
+			return 1;
+		}
+	}
+	else if(obj->body.otype == props->urid.patch_put)
+	{
+		const LV2_Atom_URID *subject = NULL;
+		const LV2_Atom_Object *body = NULL;
+
+		LV2_Atom_Object_Query q [] = {
+			{ props->urid.patch_subject, (const LV2_Atom **)&subject },
+			{ props->urid.patch_body, (const LV2_Atom **)&body },
+			LV2_ATOM_OBJECT_QUERY_END
+		};
+		lv2_atom_object_query(obj, q);
+
+		if(!body || !lv2_atom_forge_is_object_type(forge, body->atom.type))
+		{
+			return 0;
+		}
+
+		// check for a matching optional subject
+		if(  (subject && props->urid.subject)
+			&& ( (subject->atom.type != props->urid.atom_urid)
+				|| (subject->body != props->urid.subject) ) )
+		{
+			return 0;
+		}
+
+		LV2_ATOM_OBJECT_FOREACH(body, prop)
+		{
+			const LV2_URID property = prop->key;
+			const LV2_Atom *value = &prop->value;
+
+			props_impl_t *impl = _props_impl_search(props, property);
+			if(impl && (impl->access == props->urid.patch_writable) )
+			{
+				_props_set(props, impl, value->type, value->size, LV2_ATOM_BODY_CONST(value));
+
+				const props_def_t *def = impl->def;
+				if(def->event_cb && (def->event_mask & PROP_EVENT_SET) )
+					def->event_cb(props->data, forge, frames, PROP_EVENT_SET, impl);
+			}
+		}
+		return 1;
+	}
+
+	return 0; // did not handle a patch event
+}
+
+static inline void
+props_set(props_t *props, LV2_Atom_Forge *forge, uint32_t frames, LV2_URID property,
+	LV2_Atom_Forge_Ref *ref)
+{
+	props_impl_t *impl = _props_impl_search(props, property);
+
+	if(impl)
+	{
+		_props_stash(props, impl);
+		if(*ref)
+			*ref = _props_get(props, forge, frames, impl);
+	}
+}
+
+static inline void
+props_stash(props_t *props, LV2_URID property)
+{
+	props_impl_t *impl = _props_impl_search(props, property);
+
+	if(impl)
+		_props_stash(props, impl);
+}
+
+static inline LV2_State_Status
+props_save(props_t *props, LV2_Atom_Forge *forge, LV2_State_Store_Function store,
+	LV2_State_Handle state, uint32_t flags, const LV2_Feature *const *features)
+{
+	const LV2_State_Map_Path *map_path = NULL;
+
+	// set POD flag if not already set by host
+	flags |= LV2_STATE_IS_POD;
+
+	for(unsigned i = 0; features[i]; i++)
+	{
+		if(!strcmp(features[i]->URI, LV2_STATE__mapPath))
+		{
+			map_path = features[i]->data;
+			break;
+		}
+	}
+
+	void *value = malloc(props->max_size); // create memory to store widest value
+	if(value)
+	{
+		for(unsigned i = 0; i < props->nimpls; i++)
+		{
+			props_impl_t *impl = &props->impls[i];
+
+			if(impl->access == props->urid.patch_readable)
+				continue; // skip read-only, as it makes no sense to restore them
+
+			// create lockfree copy of value, store() may well be blocking
+			_impl_spin_lock(impl);
+
+			const uint32_t size = _impl_size_get(impl);
+			memcpy(value, impl->stash, size);
+
+			_impl_unlock(impl);
+
+			if( map_path && (impl->type->urid == forge->Path) )
+			{
+				const char *path = strstr(value, "file://")
+					? value + 7 // skip "file://"
+					: value;
+				char *abstract = map_path->abstract_path(map_path->handle, path);
+				if(abstract && strcmp(abstract, path))
+				{
+					store(state, impl->property, abstract, strlen(abstract) + 1, impl->type->urid, flags);
+					free(abstract);
+				}
+			}
+			else // !Path
+			{
+				store(state, impl->property, value, size, impl->type->urid, flags);
+			}
+
+			const props_def_t *def = impl->def;
+			if(def->event_cb && (def->event_mask & PROP_EVENT_SAVE) )
+				def->event_cb(props->data, forge, 0, PROP_EVENT_SAVE, impl);
+		}
+
+		free(value);
+	}
+
+	return LV2_STATE_SUCCESS;
+}
+
+static inline LV2_State_Status
+props_restore(props_t *props, LV2_Atom_Forge *forge, LV2_State_Retrieve_Function retrieve,
+	LV2_State_Handle state, uint32_t flags, const LV2_Feature *const *features)
+{
+	const LV2_State_Map_Path *map_path = NULL;
+
+	for(unsigned i = 0; features[i]; i++)
+	{
+		if(!strcmp(features[i]->URI, LV2_STATE__mapPath))
+			map_path = features[i]->data;
+	}
+
+	for(unsigned i = 0; i < props->nimpls; i++)
+	{
+		props_impl_t *impl = &props->impls[i];
+
+		if(impl->access == props->urid.patch_readable)
+			continue; // skip read-only, as it makes no sense to restore them
+
+		size_t size;
+		uint32_t type;
+		uint32_t _flags;
+		const void *value = retrieve(state, impl->property, &size, &type, &_flags);
+
+		if(value)
+		{
+			if( map_path && (impl->type->urid == forge->Path) )
+			{
+				char *absolute = map_path->absolute_path(map_path->handle, value);
+				if(absolute)
+				{
+					_props_set(props, impl, type, strlen(absolute) + 1, absolute);
+					free(absolute);
+				}
+			}
+			else // !Path
+			{
+				_props_set(props, impl, type, size, value);
+			}
+
+			const props_def_t *def = impl->def;
+			if(def->event_cb && (def->event_mask & PROP_EVENT_RESTORE) )
+				def->event_cb(props->data, forge, 0, PROP_EVENT_RESTORE, impl);
+		}
+		else
+		{
+			fprintf(stderr, "props_restore: no property '%s'.\n", impl->def->property);
+		}
+	}
+
+	return LV2_STATE_SUCCESS;
+}
+
+// undefinitions
+#undef PROPS_TYPE_N
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _LV2_PROPS_H_
diff --git a/props.lv2/test/chunk.bin b/props.lv2/test/chunk.bin
new file mode 100644
index 0000000..b66efb8
--- /dev/null
+++ b/props.lv2/test/chunk.bin
diff --git a/props.lv2/test/manifest.ttl.in b/props.lv2/test/manifest.ttl.in
new file mode 100644
index 0000000..c477aeb
--- /dev/null
+++ b/props.lv2/test/manifest.ttl.in
@@ -0,0 +1,28 @@
+# Copyright (c) 2015 Hanspeter Portner (dev@open-music-kontrollers.ch)
+#
+# This is free software: you can redistribute it and/or modify
+# it under the terms of the Artistic License 2.0 as published by
+# The Perl Foundation.
+#
+# This source 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
+# Artistic License 2.0 for more details.
+#
+# You should have received a copy of the Artistic License 2.0
+# along the source as a COPYING file. If not, obtain it from
+# http://www.perlfoundation.org/artistic_license_2_0.
+
+@prefix lv2:      <http://lv2plug.in/ns/lv2core#> .
+@prefix owl:			<http://www.w3.org/2002/07/owl#> .
+@prefix rdfs:     <http://www.w3.org/2000/01/rdf-schema#> .
+
+@prefix props:		<http://open-music-kontrollers.ch/lv2/props#> .
+
+# Orbit Looper
+props:test
+	a lv2:Plugin ;
+	lv2:minorVersion @PROPS_MINOR_VERSION@ ;
+	lv2:microVersion @PROPS_MICRO_VERSION@ ;
+	lv2:binary <props@LIB_EXT@> ;
+	rdfs:seeAlso <props.ttl> .
diff --git a/props.lv2/test/props.c b/props.lv2/test/props.c
new file mode 100644
index 0000000..516d48c
--- /dev/null
+++ b/props.lv2/test/props.c
@@ -0,0 +1,580 @@
+/*
+ * Copyright (c) 2015 Hanspeter Portner (dev@open-music-kontrollers.ch)
+ *
+ * This is free software: you can redistribute it and/or modify
+ * it under the terms of the Artistic License 2.0 as published by
+ * The Perl Foundation.
+ *
+ * This source 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
+ * Artistic License 2.0 for more details.
+ *
+ * You should have received a copy of the Artistic License 2.0
+ * along the source as a COPYING file. If not, obtain it from
+ * http://www.perlfoundation.org/artistic_license_2_0.
+ */
+
+#include <stdio.h>
+
+#include <props.h>
+
+#include <lv2/lv2plug.in/ns/ext/log/log.h>
+
+#define PROPS_PREFIX		"http://open-music-kontrollers.ch/lv2/props#"
+#define PROPS_TEST_URI	PROPS_PREFIX"test"
+
+#define MAX_NPROPS 33
+#define MAX_STRLEN 256
+
+typedef struct _plugstate0_t plugstate0_t;
+typedef struct _plugstate1_t plugstate1_t;
+typedef struct _plughandle_t plughandle_t;
+
+struct _plugstate0_t {
+	int32_t val1;
+	int64_t val2;
+	float val3;
+	double val4;
+	int32_t val5;
+	int32_t val6;
+	char val7 [MAX_STRLEN];
+};
+
+struct _plugstate1_t {
+	int32_t val1;
+	int64_t val2;
+	float val3;
+	double val4;
+	char val5 [MAX_STRLEN];
+	char val6 [MAX_STRLEN];
+	uint8_t val7 [MAX_STRLEN];
+};
+
+struct _plughandle_t {
+	LV2_URID_Map *map;
+	LV2_Log_Log *log;
+	LV2_Atom_Forge forge;
+	LV2_Atom_Forge_Ref ref;
+
+	LV2_URID log_trace;
+	LV2_URID log_note;
+
+	PROPS_T(props, MAX_NPROPS);
+
+	plugstate0_t dyn;
+	plugstate0_t _dyn;
+
+	plugstate1_t stat;
+	plugstate1_t _stat;
+
+	struct {
+		LV2_URID stat2;
+		LV2_URID stat4;
+		LV2_URID dyn2;
+		LV2_URID dyn4;
+	} urid;
+
+	const LV2_Atom_Sequence *event_in;
+	LV2_Atom_Sequence *event_out;
+};
+
+static int
+_log_vprintf(plughandle_t *handle, LV2_URID type, const char *fmt, va_list args)
+{
+	return handle->log->vprintf(handle->log->handle, type, fmt, args);
+}
+
+// non-rt || rt with LV2_LOG__Trace
+static int
+_log_printf(plughandle_t *handle, LV2_URID type, const char *fmt, ...)
+{
+  va_list args;
+	int ret;
+
+  va_start (args, fmt);
+	ret = _log_vprintf(handle, type, fmt, args);
+  va_end(args);
+
+	return ret;
+}
+
+static void
+_intercept(void *data, LV2_Atom_Forge *forge, int64_t frames,
+	props_event_t event, props_impl_t *impl)
+{
+	plughandle_t *handle = data;
+
+	switch(event)
+	{
+		case PROP_EVENT_GET:
+		{
+			_log_printf(handle, handle->log_trace, "GET     : %s", impl->def->label);
+			break;
+		}
+		case PROP_EVENT_SET:
+		{
+			_log_printf(handle, handle->log_trace, "SET     : %s", impl->def->label);
+			break;
+		}
+		case PROP_EVENT_REGISTER:
+		{
+			_log_printf(handle, handle->log_trace, "REGISTER: %s", impl->def->label);
+			break;
+		}
+		case PROP_EVENT_SAVE:
+		{
+			_log_printf(handle, handle->log_note, "SAVE    : %s", impl->def->label);
+			break;
+		}
+		case PROP_EVENT_RESTORE:
+		{
+			_log_printf(handle, handle->log_note, "RESTORE : %s", impl->def->label);
+			break;
+		}
+	}
+}
+
+static void
+_intercept_dyn1(void *data, LV2_Atom_Forge *forge, int64_t frames,
+	props_event_t event, props_impl_t *impl)
+{
+	plughandle_t *handle = data;
+
+	_intercept(data, forge, frames, event, impl);
+
+	if(event & PROP_EVENT_WRITE)
+	{
+		handle->dyn.val2 = handle->dyn.val1 * 2;
+
+		props_set(&handle->props, forge, frames, handle->urid.dyn2, &handle->ref);
+	}
+}
+
+static void
+_intercept_dyn3(void *data, LV2_Atom_Forge *forge, int64_t frames,
+	props_event_t event, props_impl_t *impl)
+{
+	plughandle_t *handle = data;
+
+	_intercept(data, forge, frames, event, impl);
+
+	if(event & PROP_EVENT_WRITE)
+	{
+		handle->dyn.val4 = handle->dyn.val3 * 2;
+
+		props_set(&handle->props, forge, frames, handle->urid.dyn4, &handle->ref);
+	}
+}
+
+static void
+_intercept_stat1(void *data, LV2_Atom_Forge *forge, int64_t frames,
+	props_event_t event, props_impl_t *impl)
+{
+	plughandle_t *handle = data;
+
+	_intercept(data, forge, frames, event, impl);
+
+	if(event & PROP_EVENT_WRITE)
+	{
+		handle->stat.val2 = handle->stat.val1 * 2;
+
+		props_set(&handle->props, forge, frames, handle->urid.stat2, &handle->ref);
+	}
+}
+
+static void
+_intercept_stat3(void *data, LV2_Atom_Forge *forge, int64_t frames,
+	props_event_t event, props_impl_t *impl)
+{
+	plughandle_t *handle = data;
+
+	_intercept(data, forge, frames, event, impl);
+
+	if(event & PROP_EVENT_WRITE)
+	{
+		handle->stat.val4 = handle->stat.val3 * 2;
+
+		props_set(&handle->props, forge, frames, handle->urid.stat4, &handle->ref);
+	}
+}
+
+static void
+_intercept_stat6(void *data, LV2_Atom_Forge *forge, int64_t frames,
+	props_event_t event, props_impl_t *impl)
+{
+	plughandle_t *handle = data;
+
+	_intercept(data, forge, frames, event, impl);
+
+	if(event & PROP_EVENT_WRITE)
+	{
+		const char *path = strstr(handle->stat.val6, "file://")
+			? handle->stat.val6 + 7 // skip "file://"
+			: handle->stat.val6;
+		FILE *f = fopen(path, "wb"); // create empty file
+		if(f)
+			fclose(f);
+	}
+}
+
+static const props_def_t dyn1 = {
+	.label = "Int",
+	.comment = "This is a 32-bit integer",
+	.property = PROPS_PREFIX"Int",
+	.access = LV2_PATCH__writable,
+	.unit = LV2_UNITS__hz,
+	.type = LV2_ATOM__Int,
+	.mode = PROP_MODE_DYNAMIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept_dyn1,
+	.minimum.i = 0,
+	.maximum.i = 10
+};
+
+static const props_def_t dyn2 = {
+	.label = "Long",
+	.comment = "This is a 64-bit integer",
+	.property = PROPS_PREFIX"Long",
+	.access = LV2_PATCH__readable,
+	.unit = LV2_UNITS__khz,
+	.type = LV2_ATOM__Long,
+	.mode = PROP_MODE_DYNAMIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept,
+	.minimum.h = 0,
+	.maximum.h = 20
+};
+
+static const props_def_t dyn3 = {
+	.label = "Float",
+	.comment = "This is a 32-bit floating point",
+	.property = PROPS_PREFIX"Float",
+	.access = LV2_PATCH__writable,
+	.unit = LV2_UNITS__mhz,
+	.type = LV2_ATOM__Float,
+	.mode = PROP_MODE_DYNAMIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept_dyn3,
+	.minimum.f = -0.5f,
+	.maximum.f = 0.5f
+};
+
+static const props_def_t dyn4 = {
+	.label = "Double",
+	.comment = "This is a 64-bit floating point",
+	.property = PROPS_PREFIX"Double",
+	.access = LV2_PATCH__readable,
+	.unit = LV2_UNITS__db,
+	.type = LV2_ATOM__Double,
+	.mode = PROP_MODE_DYNAMIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept,
+	.minimum.d = -1.0,
+	.maximum.d = 1.0
+};
+
+static const props_scale_point_t scale_points5 [] = {
+	{.label = "One",		.value.i = 0},
+	{.label = "Two",		.value.i = 1},
+	{.label = "Three",	.value.i = 2},
+	{.label = "Four",		.value.i = 3},
+	{.label = NULL } // sentinel
+};
+
+static const props_def_t dyn5 = {
+	.label = "scaleInt",
+	.comment = "This is a 32-bit integer enumeration",
+	.property = PROPS_PREFIX"scaleInt",
+	.access = LV2_PATCH__writable,
+	.type = LV2_ATOM__Int,
+	.mode = PROP_MODE_DYNAMIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept,
+	.minimum.i = 0,
+	.maximum.i = 3,
+	.scale_points = scale_points5
+};
+
+static const props_def_t dyn6 = {
+	.label = "Bool",
+	.comment = "This is a boolean",
+	.property = PROPS_PREFIX"Bool",
+	.access = LV2_PATCH__writable,
+	.type = LV2_ATOM__Bool,
+	.mode = PROP_MODE_DYNAMIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept,
+	.minimum.d = 0,
+	.maximum.d = 1
+};
+
+static const props_def_t dyn7 = {
+	.label = "String",
+	.comment = "This is a string",
+	.property = PROPS_PREFIX"String",
+	.access = LV2_PATCH__writable,
+	.type = LV2_ATOM__String,
+	.mode = PROP_MODE_DYNAMIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept,
+	.max_size = MAX_STRLEN // strlen
+};
+
+static const props_def_t stat1 = {
+	.label = "statInt",
+	.property = PROPS_PREFIX"statInt",
+	.access = LV2_PATCH__writable,
+	.type = LV2_ATOM__Int,
+	.mode = PROP_MODE_STATIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept_stat1,
+};
+
+static const props_def_t stat2 = {
+	.label = "statLong",
+	.property = PROPS_PREFIX"statLong",
+	.access = LV2_PATCH__readable,
+	.type = LV2_ATOM__Long,
+	.mode = PROP_MODE_STATIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept,
+};
+
+static const props_def_t stat3 = {
+	.label = "statFloat",
+	.property = PROPS_PREFIX"statFloat",
+	.access = LV2_PATCH__writable,
+	.type = LV2_ATOM__Float,
+	.mode = PROP_MODE_STATIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept_stat3,
+};
+
+static const props_def_t stat4 = {
+	.label = "statDouble",
+	.property = PROPS_PREFIX"statDouble",
+	.access = LV2_PATCH__readable,
+	.type = LV2_ATOM__Double,
+	.mode = PROP_MODE_STATIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept,
+};
+
+static const props_def_t stat5 = {
+	.label = "statString",
+	.property = PROPS_PREFIX"statString",
+	.access = LV2_PATCH__writable,
+	.type = LV2_ATOM__String,
+	.mode = PROP_MODE_STATIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept,
+	.max_size = MAX_STRLEN // strlen
+};
+
+static const props_def_t stat6 = {
+	.label = "statPath",
+	.property = PROPS_PREFIX"statPath",
+	.access = LV2_PATCH__writable,
+	.type = LV2_ATOM__Path,
+	.mode = PROP_MODE_STATIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept_stat6,
+	.max_size = MAX_STRLEN // strlen
+};
+
+static const props_def_t stat7 = {
+	.label = "statChunk",
+	.property = PROPS_PREFIX"statChunk",
+	.access = LV2_PATCH__writable,
+	.type = LV2_ATOM__Chunk,
+	.mode = PROP_MODE_STATIC,
+	.event_mask = PROP_EVENT_ALL,
+	.event_cb = _intercept,
+	.max_size = MAX_STRLEN // strlen
+};
+
+static LV2_Handle
+instantiate(const LV2_Descriptor* descriptor, double rate,
+	const char *bundle_path, const LV2_Feature *const *features)
+{
+	plughandle_t *handle = calloc(1, sizeof(plughandle_t));
+	if(!handle)
+		return NULL;
+
+	for(unsigned i=0; features[i]; i++)
+	{
+		if(!strcmp(features[i]->URI, LV2_URID__map))
+			handle->map = features[i]->data;
+		else if(!strcmp(features[i]->URI, LV2_LOG__log))
+			handle->log = features[i]->data;
+	}
+
+	if(!handle->map)
+	{
+		fprintf(stderr,
+			"%s: Host does not support urid:map\n", descriptor->URI);
+		free(handle);
+		return NULL;
+	}
+	if(!handle->log)
+	{
+		fprintf(stderr,
+			"%s: Host does not support log:log\n", descriptor->URI);
+		free(handle);
+		return NULL;
+	}
+
+	handle->log_trace = handle->map->map(handle->map->handle, LV2_LOG__Trace);
+	handle->log_note = handle->map->map(handle->map->handle, LV2_LOG__Note);
+
+	lv2_atom_forge_init(&handle->forge, handle->map);
+	if(!props_init(&handle->props, MAX_NPROPS, descriptor->URI, handle->map, handle))
+	{
+		fprintf(stderr, "failed to initialize property structure\n");
+		free(handle);
+		return NULL;
+	}
+
+	plugstate0_t *dyn = &handle->dyn;
+	plugstate0_t *_dyn = &handle->_dyn;
+	plugstate1_t *stat = &handle->stat;
+	plugstate1_t *_stat = &handle->_stat;
+
+	if(  !props_register(&handle->props, &dyn1, &dyn->val1, &_dyn->val1)
+		|| !(handle->urid.dyn2 =
+				props_register(&handle->props, &dyn2, &dyn->val2, &_dyn->val2))
+		|| !props_register(&handle->props, &dyn3, &dyn->val3, &_dyn->val3)
+		|| !(handle->urid.dyn4 =
+				props_register(&handle->props, &dyn4, &dyn->val4, &_dyn->val4))
+		|| !props_register(&handle->props, &dyn5, &dyn->val5, &_dyn->val5)
+		|| !props_register(&handle->props, &dyn6, &dyn->val6, &_dyn->val6)
+		|| !props_register(&handle->props, &dyn7, &dyn->val7, &_dyn->val7)
+
+		|| !props_register(&handle->props, &stat1, &stat->val1, &_stat->val1)
+		|| !(handle->urid.stat2 =
+				props_register(&handle->props, &stat2, &stat->val2, &_stat->val2))
+		|| !props_register(&handle->props, &stat3, &stat->val3, &_stat->val3)
+		|| !(handle->urid.stat4 =
+				props_register(&handle->props, &stat4, &stat->val4, &_stat->val4))
+		|| !props_register(&handle->props, &stat5, &stat->val5, &_stat->val5)
+		|| !props_register(&handle->props, &stat6, &stat->val6, &_stat->val6)
+		|| !props_register(&handle->props, &stat7, &stat->val7, &_stat->val7) )
+	{
+		_log_printf(handle, handle->log_trace, "ERR     : registering");
+		free(handle);
+		return NULL;
+	}
+
+	return handle;
+}
+
+static void
+connect_port(LV2_Handle instance, uint32_t port, void *data)
+{
+	plughandle_t *handle = (plughandle_t *)instance;
+
+	switch(port)
+	{
+		case 0:
+			handle->event_in = (const LV2_Atom_Sequence *)data;
+			break;
+		case 1:
+			handle->event_out = (LV2_Atom_Sequence *)data;
+			break;
+		default:
+			break;
+	}
+}
+
+static void
+run(LV2_Handle instance, uint32_t nsamples)
+{
+	plughandle_t *handle = instance;
+
+	uint32_t capacity = handle->event_out->atom.size;
+	LV2_Atom_Forge_Frame frame;
+	lv2_atom_forge_set_buffer(&handle->forge, (uint8_t *)handle->event_out, capacity);
+	handle->ref = lv2_atom_forge_sequence_head(&handle->forge, &frame, 0);
+
+	LV2_ATOM_SEQUENCE_FOREACH(handle->event_in, ev)
+	{
+		const LV2_Atom_Object *obj = (const LV2_Atom_Object *)&ev->body;
+
+		if(handle->ref)
+			props_advance(&handle->props, &handle->forge, ev->time.frames, obj, &handle->ref); //TODO handle return
+	}
+	if(handle->ref)
+		lv2_atom_forge_pop(&handle->forge, &frame);
+	else
+		lv2_atom_sequence_clear(handle->event_out);
+}
+
+static void
+cleanup(LV2_Handle instance)
+{
+	plughandle_t *handle = instance;
+
+	free(handle);
+}
+
+static LV2_State_Status
+_state_save(LV2_Handle instance, LV2_State_Store_Function store,
+	LV2_State_Handle state, uint32_t flags,
+	const LV2_Feature *const *features)
+{
+	plughandle_t *handle = (plughandle_t *)instance;
+
+	return props_save(&handle->props, &handle->forge, store, state, flags, features);
+}
+
+static LV2_State_Status
+_state_restore(LV2_Handle instance, LV2_State_Retrieve_Function retrieve,
+	LV2_State_Handle state, uint32_t flags,
+	const LV2_Feature *const *features)
+{
+	plughandle_t *handle = (plughandle_t *)instance;
+
+	return props_restore(&handle->props, &handle->forge, retrieve, state, flags, features);
+}
+
+LV2_State_Interface state_iface = {
+	.save = _state_save,
+	.restore = _state_restore
+};
+
+static const void *
+extension_data(const char *uri)
+{
+	if(!strcmp(uri, LV2_STATE__interface))
+		return &state_iface;
+	return NULL;
+}
+
+const LV2_Descriptor props_test = {
+	.URI						= PROPS_TEST_URI,
+	.instantiate		= instantiate,
+	.connect_port		= connect_port,
+	.activate				= NULL,
+	.run						= run,
+	.deactivate			= NULL,
+	.cleanup				= cleanup,
+	.extension_data	= extension_data
+};
+
+#ifdef _WIN32
+__declspec(dllexport)
+#else
+__attribute__((visibility("default")))
+#endif
+const LV2_Descriptor*
+lv2_descriptor(uint32_t index)
+{
+	switch(index)
+	{
+		case 0:
+			return &props_test;
+		default:
+			return NULL;
+	}
+}
diff --git a/props.lv2/test/props.ttl b/props.lv2/test/props.ttl
new file mode 100644
index 0000000..17a8041
--- /dev/null
+++ b/props.lv2/test/props.ttl
@@ -0,0 +1,152 @@
+# Copyright (c) 2015 Hanspeter Portner (dev@open-music-kontrollers.ch)
+#
+# This is free software: you can redistribute it and/or modify
+# it under the terms of the Artistic License 2.0 as published by
+# The Perl Foundation.
+#
+# This source 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
+# Artistic License 2.0 for more details.
+#
+# You should have received a copy of the Artistic License 2.0
+# along the source as a COPYING file. If not, obtain it from
+# http://www.perlfoundation.org/artistic_license_2_0.
+
+@prefix owl:			<http://www.w3.org/2002/07/owl#> .
+@prefix foaf:			<http://xmlns.com/foaf/0.1/> .
+@prefix doap:			<http://usefulinc.com/ns/doap#> .
+@prefix rdf:			<http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
+@prefix rdfs: 		<http://www.w3.org/2000/01/rdf-schema#> .
+@prefix lv2:			<http://lv2plug.in/ns/lv2core#> .
+@prefix atom:			<http://lv2plug.in/ns/ext/atom#> .
+@prefix urid:			<http://lv2plug.in/ns/ext/urid#> .
+@prefix state:		<http://lv2plug.in/ns/ext/state#> .
+@prefix patch:		<http://lv2plug.in/ns/ext/patch#> .
+@prefix log:			<http://lv2plug.in/ns/ext/log#> .
+@prefix units:		<http://lv2plug.in/ns/extensions/units#> .
+@prefix xsd:			<http://www.w3.org/2001/XMLSchema#> .
+
+@prefix lic:			<http://opensource.org/licenses/> .
+@prefix omk:			<http://open-music-kontrollers.ch/ventosus#> .
+@prefix proj:			<http://open-music-kontrollers.ch/lv2/> .
+@prefix props:		<http://open-music-kontrollers.ch/lv2/props#> .
+
+# Maintainer
+omk:me
+	a foaf:Person ;
+	foaf:name "Hanspeter Portner" ;
+	foaf:mbox <mailto:dev@open-music-kontrollers.ch> ;
+	foaf:homepage <http://open-music-kontrollers.ch> .
+
+# Project
+proj:props
+	a doap:Project ;
+	doap:maintainer omk:me ;
+	doap:name "Props Bundle" .
+
+props:statInt
+	a lv2:Parameter ;
+	rdfs:range atom:Int ;
+	rdfs:label "statInt" ;
+	rdfs:comment "This is a 32-bit integer" ;
+	units:unit units:hz ;
+	lv2:minimum 0 ;
+	lv2:maximum 10 .
+
+props:statLong
+	a lv2:Parameter ;
+	rdfs:range atom:Long ;
+	rdfs:label "statLong" ;
+	rdfs:comment "This is a 64-bit integer" ;
+	units:unit units:khz ;
+	lv2:minimum 0 ;
+	lv2:maximum 20 .
+
+props:statFloat
+	a lv2:Parameter ;
+	rdfs:range atom:Float ;
+	rdfs:label "statFloat" ;
+	rdfs:comment "This is a 32-bit float" ;
+	units:unit units:mhz ;
+	lv2:minimum -0.5 ;
+	lv2:maximum 0.5 .
+
+props:statDouble
+	a lv2:Parameter ;
+	rdfs:range atom:Double ;
+	rdfs:label "statDouble" ;
+	rdfs:comment "This is a 64-bit double" ;
+	units:unit units:db ;
+	lv2:minimum -1.0 ;
+	lv2:maximum 1.0 .
+
+props:statString
+	a lv2:Parameter ;
+	rdfs:range atom:String ;
+	rdfs:label "statString" ;
+	rdfs:comment "This is a string" .
+
+props:statPath
+	a lv2:Parameter ;
+	rdfs:range atom:Path ;
+	rdfs:label "statPath" ;
+	rdfs:comment "This is a path" .
+
+props:statChunk
+	a lv2:Parameter ;
+	rdfs:range atom:Chunk;
+	rdfs:label "statChunk" ;
+	rdfs:comment "This is a chunk" .
+
+# Looper Test
+props:test
+	a lv2:Plugin ,
+		lv2:ConverterPlugin ;
+	doap:name "Props Test" ;
+	doap:license lic:Artistic-2.0 ;
+	lv2:project proj:props ;
+	lv2:extensionData	state:interface ;
+	lv2:requiredFeature urid:map, log:log, state:loadDefaultState ;
+	lv2:optionalFeature lv2:isLive, lv2:hardRTCapable ;
+
+	lv2:port [
+		# sink event port
+	  a lv2:InputPort ,
+			atom:AtomPort ;
+		atom:bufferType atom:Sequence ;
+		atom:supports patch:Message ;
+		lv2:index 0 ;
+		lv2:symbol "event_in" ;
+		lv2:name "Event Input" ;
+		lv2:designation lv2:control ;
+	] , [
+		# source event port
+	  a lv2:OutputPort ,
+			atom:AtomPort ;
+		atom:bufferType atom:Sequence ;
+		atom:supports patch:Message ;
+		lv2:index 1 ;
+		lv2:symbol "event_out" ;
+		lv2:name "Event Output" ;
+		lv2:designation lv2:control ;
+	] ;
+
+	patch:writable
+		props:statInt ,
+		props:statFloat ,
+		props:statString ,
+		props:statPath ,
+		props:statChunk ;
+
+	patch:readable
+		props:statLong ,
+		props:statDouble ;
+
+	state:state [
+		props:statInt 4 ;
+		props:statFloat "0.4"^^xsd:float ;
+		props:statString "Hello world" ;
+		props:statPath <manifest.ttl> ;
+		props:statChunk "Q"^^xsd:base64Binary ;
+	] .