Initial import of lv2plug.in universe.

5 files changed, 711 insertions, 0 deletions

diff --git a/ext/event.lv2/event-helpers.h b/ext/event.lv2/event-helpers.h
new file mode 100644
index 0000000..14500b8
--- /dev/null
+++ b/ext/event.lv2/event-helpers.h
@@ -0,0 +1,243 @@
+/* lv2_event_helpers.h - Helper functions for the LV2 events extension.
+ *
+ * Copyright (C) 2008-2009 David Robillard <http://drobilla.net>
+ *
+ * This header is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This header 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 Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this header; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 01222-1307 USA
+ */
+
+#ifndef LV2_EVENT_HELPERS_H
+#define LV2_EVENT_HELPERS_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+#include "event.lv2/event.h"
+
+/** @file
+ * Helper functions for the LV2 Event extension
+ * <http://lv2plug.in/ns/ext/event>.
+ *
+ * These functions are provided for convenience only, use of them is not
+ * required for supporting lv2ev (i.e. the events extension is defined by the
+ * raw buffer format described in lv2_event.h and NOT by this API).
+ *
+ * Note that these functions are all static inline which basically means:
+ * do not take the address of these functions. */
+
+
+/** Pad a size to 64 bits (for event sizes) */
+static inline uint16_t
+lv2_event_pad_size(uint16_t size)
+{
+	return (size + 7) & (~7);
+}
+
+
+/** Initialize (empty, reset..) an existing event buffer.
+ * The contents of buf are ignored entirely and overwritten, except capacity
+ * which is unmodified. */
+static inline void
+lv2_event_buffer_reset(LV2_Event_Buffer* buf, uint16_t stamp_type, uint8_t *data)
+{
+	buf->data = data;
+	buf->header_size = sizeof(LV2_Event_Buffer);
+	buf->stamp_type = stamp_type;
+	buf->event_count = 0;
+	buf->size = 0;
+}
+
+
+/** Allocate a new, empty event buffer. */
+static inline LV2_Event_Buffer*
+lv2_event_buffer_new(uint32_t capacity, uint16_t stamp_type)
+{
+	LV2_Event_Buffer* buf = (LV2_Event_Buffer*)malloc(sizeof(LV2_Event_Buffer) + capacity);
+	if (buf != NULL) {
+		buf->capacity = capacity;
+		lv2_event_buffer_reset(buf, stamp_type, (uint8_t *)(buf + 1));
+		return buf;
+	} else {
+		return NULL;
+	}
+}
+
+
+/** An iterator over an LV2_Event_Buffer.
+ *
+ * Multiple simultaneous read iterators over a single buffer is fine,
+ * but changing the buffer invalidates all iterators (e.g. RW Lock). */
+typedef struct {
+	LV2_Event_Buffer* buf;
+	uint32_t          offset;
+} LV2_Event_Iterator;
+
+
+/** Reset an iterator to point to the start of @a buf.
+ * @return True if @a iter is valid, otherwise false (buffer is empty) */
+static inline bool
+lv2_event_begin(LV2_Event_Iterator* iter,
+                LV2_Event_Buffer*   buf)
+{
+	iter->buf = buf;
+	iter->offset = 0;
+	return (buf->size > 0);
+}
+
+
+/** Check if @a iter is valid..
+ * @return True if @a iter is valid, otherwise false (past end of buffer) */
+static inline bool
+lv2_event_is_valid(LV2_Event_Iterator* iter)
+{
+	return (iter->offset < iter->buf->size);
+}
+
+
+/** Advance @a iter forward one event.
+ * @a iter must be valid.
+ * @return True if @a iter is valid, otherwise false (reached end of buffer) */
+static inline bool
+lv2_event_increment(LV2_Event_Iterator* iter)
+{
+	assert(lv2_event_is_valid(iter));
+
+	LV2_Event* const ev = (LV2_Event*)(
+			(uint8_t*)iter->buf->data + iter->offset);
+
+	iter->offset += lv2_event_pad_size(sizeof(LV2_Event) + ev->size);
+
+	return true;
+}
+
+
+/** Dereference an event iterator (get the event currently pointed at).
+ * @a iter must be valid.
+ * @a data if non-NULL, will be set to point to the contents of the event
+ *         returned.
+ * @return A Pointer to the event @a iter is currently pointing at, or NULL
+ *         if the end of the buffer is reached (in which case @a data is
+ *         also set to NULL). */
+static inline LV2_Event*
+lv2_event_get(LV2_Event_Iterator* iter,
+              uint8_t**           data)
+{
+	assert(lv2_event_is_valid(iter));
+
+	LV2_Event* const ev = (LV2_Event*)(
+			(uint8_t*)iter->buf->data + iter->offset);
+
+	if (data)
+		*data = (uint8_t*)ev + sizeof(LV2_Event);
+
+	return ev;
+}
+
+
+/** Write an event at @a iter.
+ * The event (if any) pointed to by @iter will be overwritten, and @a iter
+ * incremented to point to the following event (i.e. several calls to this
+ * function can be done in sequence without twiddling iter in-between).
+ * @return True if event was written, otherwise false (buffer is full). */
+static inline bool
+lv2_event_write(LV2_Event_Iterator* iter,
+                uint32_t            frames,
+                uint32_t            subframes,
+                uint16_t            type,
+                uint16_t            size,
+                const uint8_t*      data)
+{
+	if (iter->buf->capacity - iter->buf->size < sizeof(LV2_Event) + size)
+		return false;
+
+	LV2_Event* const ev = (LV2_Event*)(
+			(uint8_t*)iter->buf->data + iter->offset);
+
+	ev->frames = frames;
+	ev->subframes = subframes;
+	ev->type = type;
+	ev->size = size;
+	memcpy((uint8_t*)ev + sizeof(LV2_Event), data, size);
+	++iter->buf->event_count;
+
+	size = lv2_event_pad_size(sizeof(LV2_Event) + size);
+	iter->buf->size += size;
+	iter->offset    += size;
+
+	return true;
+}
+
+
+/** Reserve space for an event in the buffer and return a pointer to
+    the memory where the caller can write the event data, or NULL if there
+    is not enough room in the buffer. */
+static inline uint8_t*
+lv2_event_reserve(LV2_Event_Iterator* iter,
+		  uint32_t frames,
+		  uint32_t subframes,
+		  uint16_t type,
+		  uint16_t size)
+{
+	size = lv2_event_pad_size(size);
+	if (iter->buf->capacity - iter->buf->size < sizeof(LV2_Event) + size)
+		return NULL;
+
+	LV2_Event* const ev = (LV2_Event*)((uint8_t*)iter->buf->data +
+					   iter->offset);
+
+	ev->frames = frames;
+	ev->subframes = subframes;
+	ev->type = type;
+	ev->size = size;
+	++iter->buf->event_count;
+
+	size = lv2_event_pad_size(sizeof(LV2_Event) + size);
+	iter->buf->size += size;
+	iter->offset    += size;
+
+	return (uint8_t*)ev + sizeof(LV2_Event);
+}
+
+
+/** Write an event at @a iter.
+ * The event (if any) pointed to by @iter will be overwritten, and @a iter
+ * incremented to point to the following event (i.e. several calls to this
+ * function can be done in sequence without twiddling iter in-between).
+ * @return True if event was written, otherwise false (buffer is full). */
+static inline bool
+lv2_event_write_event(LV2_Event_Iterator* iter,
+                      const LV2_Event*    ev,
+                      const uint8_t*      data)
+{
+	if (iter->buf->capacity - iter->buf->size < sizeof(LV2_Event) + ev->size)
+		return false;
+
+	LV2_Event* const write_ev = (LV2_Event*)(
+			(uint8_t*)iter->buf->data + iter->offset);
+
+	*write_ev = *ev;
+	memcpy((uint8_t*)write_ev + sizeof(LV2_Event), data, ev->size);
+	++iter->buf->event_count;
+
+	const uint16_t size = lv2_event_pad_size(sizeof(LV2_Event) + ev->size);
+	iter->buf->size += size;
+	iter->offset    += size;
+
+	return true;
+}
+
+#endif /* LV2_EVENT_HELPERS_H */
+
diff --git a/ext/event.lv2/event.h b/ext/event.lv2/event.h
new file mode 100644
index 0000000..7fb189c
--- /dev/null
+++ b/ext/event.lv2/event.h
@@ -0,0 +1,259 @@
+/* lv2_event.h - C header file for the LV2 events extension.
+ *
+ * Copyright (C) 2006-2007 Lars Luthman <lars.luthman@gmail.com>
+ * Copyright (C) 2008-2009 David Robillard <http://drobilla.net>
+ *
+ * This header is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This header 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 Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this header; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 01222-1307 USA
+ */
+
+#ifndef LV2_EVENT_H
+#define LV2_EVENT_H
+
+#define LV2_EVENT_URI "http://lv2plug.in/ns/ext/event"
+#define LV2_EVENT_AUDIO_STAMP 0
+
+#include <stdint.h>
+
+/** @file
+ * C header for the LV2 Event extension <http://lv2plug.in/ns/ext/event>.
+ *
+ * This extension is a generic transport mechanism for time stamped events
+ * of any type (e.g. MIDI, OSC, ramps, etc).  Each port can transport mixed
+ * events of any type; the type of events and timestamps are defined by a URI
+ * which is mapped to an integer by the host for performance reasons.
+ *
+ * This extension requires the host to support the LV2 URI Map extension.
+ * Any host which supports this extension MUST guarantee that any call to
+ * the LV2 URI Map uri_to_id function with the URI of this extension as the
+ * 'map' argument returns a value within the range of uint16_t.
+ */
+
+
+/** The best Pulses Per Quarter Note for tempo-based uint32_t timestmaps.
+ * Equal to 2^12 * 5 * 7 * 9 * 11 * 13 * 17, which is evenly divisble
+ * by all integers from 1 through 18 inclusive, and powers of 2 up to 2^12.
+ */
+static const uint32_t LV2_EVENT_PPQN = 3136573440U;
+
+
+/** An LV2 event (header only).
+ *
+ * LV2 events are generic time-stamped containers for any type of event.
+ * The type field defines the format of a given event's contents.
+ *
+ * This struct defines the header of an LV2 event.  An LV2 event is a single
+ * chunk of POD (plain old data), usually contained in a flat buffer
+ * (see LV2_EventBuffer below).  Unless a required feature says otherwise,
+ * hosts may assume a deep copy of an LV2 event can be created safely
+ * using a simple:
+ *
+ * memcpy(ev_copy, ev, sizeof(LV2_Event) + ev->size);  (or equivalent)
+ */
+typedef struct {
+
+	/** The frames portion of timestamp.  The units used here can optionally be
+	 * set for a port (with the lv2ev:timeUnits property), otherwise this
+	 * is audio frames, corresponding to the sample_count parameter of the
+	 * LV2 run method (e.g. frame 0 is the first frame for that call to run).
+	 */
+	uint32_t frames;
+
+	/** The sub-frames portion of timestamp.  The units used here can
+	 * optionally be set for a port (with the lv2ev:timeUnits property),
+	 * otherwise this is 1/(2^32) of an audio frame.
+	 */
+	uint32_t subframes;
+
+	/** The type of this event, as a number which represents some URI
+	 * defining an event type.  This value MUST be some value previously
+	 * returned from a call to the uri_to_id function defined in the LV2
+	 * URI map extension (see lv2_uri_map.h).
+	 * There are special rules which must be followed depending on the type
+	 * of an event.  If the plugin recognizes an event type, the definition
+	 * of that event type will describe how to interpret the event, and
+	 * any required behaviour.  Otherwise, if the type is 0, this event is a
+	 * non-POD event and lv2_event_unref MUST be called if the event is
+	 * 'dropped' (see above).  Even if the plugin does not understand an event,
+	 * it may pass the event through to an output by simply copying (and NOT
+	 * calling lv2_event_unref).  These rules are designed to allow for generic
+	 * event handling plugins and large non-POD events, but with minimal hassle
+	 * on simple plugins that "don't care" about these more advanced features.
+	 */
+	uint16_t type;
+
+	/** The size of the data portion of this event in bytes, which immediately
+	 * follows.  The header size (12 bytes) is not included in this value.
+	 */
+	uint16_t size;
+
+	/* size bytes of data follow here */
+
+} LV2_Event;
+
+
+
+/** A buffer of LV2 events (header only).
+ *
+ * Like events (which this contains) an event buffer is a single chunk of POD:
+ * the entire buffer (including contents) can be copied with a single memcpy.
+ * The first contained event begins sizeof(LV2_EventBuffer) bytes after
+ * the start of this struct.
+ *
+ * After this header, the buffer contains an event header (defined by struct
+ * LV2_Event), followed by that event's contents (padded to 64 bits), followed by
+ * another header, etc:
+ *
+ * |       |       |       |       |       |       |
+ * | | | | | | | | | | | | | | | | | | | | | | | | |
+ * |FRAMES |SUBFRMS|TYP|LEN|DATA..DATA..PAD|FRAMES | ...
+ */
+typedef struct {
+
+	/** The contents of the event buffer.  This may or may not reside in the
+	 * same block of memory as this header, plugins must not assume either.
+	 * The host guarantees this points to at least capacity bytes of allocated
+	 * memory (though only size bytes of that are valid events).
+	 */
+	uint8_t* data;
+
+	/** The size of this event header in bytes (including everything).
+	 *
+	 * This is to allow for extending this header in the future without
+	 * breaking binary compatibility.  Whenever this header is copied,
+	 * it MUST be done using this field (and NOT the sizeof this struct).
+	 */
+	uint16_t header_size;
+
+	/** The type of the time stamps for events in this buffer.
+	 * As a special exception, '0' always means audio frames and subframes
+	 * (1/UINT32_MAX'th of a frame) in the sample rate passed to instantiate.
+	 * INPUTS: The host must set this field to the numeric ID of some URI
+	 *     defining the meaning of the frames/subframes fields of contained
+	 *     events (obtained by the LV2 URI Map uri_to_id function with the URI
+	 *     of this extension as the 'map' argument, see lv2_uri_map.h).
+	 *     The host must never pass a plugin a buffer which uses a stamp type
+	 *     the plugin does not 'understand'.  The value of this field must
+	 *     never change, except when connect_port is called on the input
+	 *     port, at which time the host MUST have set the stamp_type field to
+	 *     the value that will be used for all subsequent run calls.
+	 * OUTPUTS: The plugin may set this to any value that has been returned
+	 *     from uri_to_id with the URI of this extension for a 'map' argument.
+	 *     When connected to a buffer with connect_port, output ports MUST set
+	 *     this field to the type of time stamp they will be writing.  On any
+	 *     call to connect_port on an event input port, the plugin may change
+	 *     this field on any output port, it is the responsibility of the host
+	 *     to check if any of these values have changed and act accordingly.
+	 */
+	uint16_t stamp_type;
+
+	/** The number of events in this buffer.
+	 * INPUTS: The host must set this field to the number of events
+	 *     contained in the data buffer before calling run().
+	 *     The plugin must not change this field.
+	 * OUTPUTS: The plugin must set this field to the number of events it
+	 *     has written to the buffer before returning from run().
+	 *     Any initial value should be ignored by the plugin.
+	 */
+	uint32_t event_count;
+
+	/** The size of the data buffer in bytes.
+	 * This is set by the host and must not be changed by the plugin.
+	 * The host is allowed to change this between run() calls.
+	 */
+	uint32_t capacity;
+
+	/** The size of the initial portion of the data buffer containing data.
+	 * INPUTS: The host must set this field to the number of bytes used
+	 *     by all events it has written to the buffer (including headers)
+	 *     before calling the plugin's run().
+	 *     The plugin must not change this field.
+	 * OUTPUTS: The plugin must set this field to the number of bytes
+	 *     used by all events it has written to the buffer (including headers)
+	 *     before returning from run().
+	 *     Any initial value should be ignored by the plugin.
+	 */
+	uint32_t size;
+
+} LV2_Event_Buffer;
+
+
+/** Opaque pointer to host data. */
+typedef void* LV2_Event_Callback_Data;
+
+
+/** The data field of the LV2_Feature for this extension.
+ *
+ * To support this feature the host must pass an LV2_Feature struct to the
+ * plugin's instantiate method with URI "http://lv2plug.in/ns/ext/event"
+ * and data pointed to an instance of this struct.
+ */
+typedef struct {
+
+	/** Opaque pointer to host data.
+	 *
+	 * The plugin MUST pass this to any call to functions in this struct.
+	 * Otherwise, it must not be interpreted in any way.
+	 */
+	LV2_Event_Callback_Data callback_data;
+
+	/** Take a reference to a non-POD event.
+	 *
+	 * If a plugin receives an event with type 0, it means the event is a
+	 * pointer to some object in memory and not a flat sequence of bytes
+	 * in the buffer.  When receiving a non-POD event, the plugin already
+	 * has an implicit reference to the event.  If the event is stored AND
+	 * passed to an output, lv2_event_ref MUST be called on that event.
+	 * If the event is only stored OR passed through, this is not necessary
+	 * (as the plugin already has 1 implicit reference).
+	 *
+	 * @param event An event received at an input that will not be copied to
+	 *              an output or stored in any way.
+	 * @param context The calling context.  (Like event types) this is a mapped
+	 *                URI, see lv2_context.h. Simple plugin with just a run()
+	 *                method should pass 0 here (the ID of the 'standard' LV2
+	 *                run context).  The host guarantees that this function is
+	 *                realtime safe iff @a context is realtime safe.
+	 *
+	 * PLUGINS THAT VIOLATE THESE RULES MAY CAUSE CRASHES AND MEMORY LEAKS.
+	 */
+	uint32_t (*lv2_event_ref)(LV2_Event_Callback_Data callback_data,
+	                          LV2_Event*              event);
+
+	/** Drop a reference to a non-POD event.
+	 *
+	 * If a plugin receives an event with type 0, it means the event is a
+	 * pointer to some object in memory and not a flat sequence of bytes
+	 * in the buffer.  If the plugin does not pass the event through to
+	 * an output or store it internally somehow, it MUST call this function
+	 * on the event (more information on using non-POD events below).
+	 *
+	 * @param event An event received at an input that will not be copied to
+	 *              an output or stored in any way.
+	 * @param context The calling context.  (Like event types) this is a mapped
+	 *                URI, see lv2_context.h. Simple plugin with just a run()
+	 *                method should pass 0 here (the ID of the 'standard' LV2
+	 *                run context).  The host guarantees that this function is
+	 *                realtime safe iff @a context is realtime safe.
+	 *
+	 * PLUGINS THAT VIOLATE THESE RULES MAY CAUSE CRASHES AND MEMORY LEAKS.
+	 */
+	uint32_t (*lv2_event_unref)(LV2_Event_Callback_Data callback_data,
+	                            LV2_Event*              event);
+
+} LV2_Event_Feature;
+
+
+#endif /* LV2_EVENT_H */
+
diff --git a/ext/event.lv2/event.ttl b/ext/event.lv2/event.ttl
new file mode 100644
index 0000000..4f939a4
--- /dev/null
+++ b/ext/event.lv2/event.ttl
@@ -0,0 +1,192 @@
+# LV2 Events Extension
+# Copyright (C) 2008 David Robillard <d@drobilla.net>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+# 
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+# 
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+
+@prefix ev:    <http://lv2plug.in/ns/ext/event#> .
+@prefix lv2:   <http://lv2plug.in/ns/lv2core#> .
+@prefix lv2ev: <http://lv2plug.in/ns/ext/event#> .
+@prefix rdf:   <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
+@prefix rdfs:  <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix doap:  <http://usefulinc.com/ns/doap#> .
+@prefix foaf:  <http://xmlns.com/foaf/0.1/> .
+
+<http://lv2plug.in/ns/ext/event> a lv2:Specification ;
+	doap:license <http://usefulinc.com/doap/licenses/mit> ;
+	doap:name "LV2 Events" ;
+	rdfs:seeAlso "event-helpers.h" ;
+    doap:release [
+        doap:revision "1" ;
+        doap:created "2008-04-04" ;
+    ] ;
+	doap:maintainer [
+		a foaf:Person ;
+		foaf:name "David Robillard" ;
+		foaf:homepage <http://drobilla.net/> ;
+		rdfs:seeAlso <http://drobilla.net/drobilla.xrdf>
+	] , [
+		a foaf:Person ;
+		foaf:name "Lars Luthman" ;
+    ] ;
+	rdfs:comment """
+This extension defines a generic time-stamped event port type, which can be
+used to create plugins that read and write real-time events, such as MIDI,
+OSC, or any other type of event payload.  The type(s) of event supported by
+a port is defined in the data file for a plugin, for example:
+<pre>
+&lt;http://example.org/some-plugin&gt;
+	lv2:port [
+		a ev:EventPort, lv2:InputPort ;
+		lv2:index 0 ;
+		ev:supportsEvent &lt;http://lv2plug.in/ns/ext/midi#MidiEvent&gt; ;
+		lv2:symbol "midi_input" ;
+		lv2:name "MIDI input" ;
+	] .
+</pre>
+""" .
+
+ev:EventPort a rdfs:Class ;
+    rdfs:label      "Event port" ;
+    rdfs:subClassOf lv2:Port ;
+    rdfs:comment    """
+Ports of this type will be connected to a struct of type LV2_Event_Buffer,
+defined in event.h.  These ports contain a sequence of generic events
+(possibly several types mixed in a single stream), the specific types of
+which are defined by some URI in another LV2 extension.
+""" .
+
+
+ev:Event a rdfs:Class ;
+	rdfs:label      "LV2 event" ;
+	rdfs:comment    """
+A single generic time-stamped event.
+
+An lv2ev:EventPort contains an LV2_Event_Buffer which contains a sequence
+of these events.  The binary format of LV2 events is defined by the
+LV2_Event struct in event.h.
+
+Specific event types (e.g. MIDI, OSC) are defined by extensions, and should
+be rdfs:subClassOf this class.
+""" .
+
+
+ev:TimeStamp a rdfs:Class ;
+	rdfs:label      "LV2 event time stamp" ;
+	rdfs:comment    """
+The time stamp of an Event.
+
+This defines the meaning of the 'frames' and 'subframes' fields of an
+LV2_Event (both unsigned 32-bit integers).
+""" .
+
+
+ev:FrameStamp a rdfs:Class ;
+	rdfs:subClassOf ev:TimeStamp ;
+	rdfs:label      "Audio frame time stamp" ;
+	rdfs:comment    """
+The default time stamp unit for an LV2 event: the frames field represents
+audio frames (in the sample rate passed to intantiate), and the subframes
+field is 1/UINT32_MAX of a frame.
+""" .
+
+
+ev:generic a lv2:PortProperty ;
+	rdfs:label "Generic event port" ;
+	rdfs:comment """
+Indicates that this port does something meaningful for any event type
+(e.g. event mixers, delays, serialisers, etc).  If this property is set, hosts
+should consider the port suitable for any type of event.  Otherwise, hosts 
+should consider the port 'appropriate' only for the specific event types
+listed with :supportsEvent.  Note that plugins must gracefully handle unknown
+event types whether or not this property is present.
+""" .
+
+
+ev:supportsEvent a rdf:Property ;
+	rdfs:domain  lv2:Port ;
+	rdfs:range   ev:Event ;
+    rdfs:label   "Supports event type" ;
+    rdfs:comment """
+Indicates that this port supports or "understands" a certain event type.
+For input ports, this means the plugin understands and does something useful
+with events of this type.  For output ports, this means the plugin may generate
+events of this type.  If the plugin never actually generates events of this type,
+but might pass them through from an input, this property should not be set (use
+ev:inheritsEvent for that).
+Plugins with event input ports must always gracefully handle any type of event,
+even if it does not 'support' it.  This property should always be set for
+event types the plugin understands/generates so hosts can discover plugins
+appropriate for a given scenario (e.g. plugins with a MIDI input).
+Hosts are not expected to consider event ports suitable for some type of
+event if the relevant :supportsEvent property is not set, unless the
+lv2ev:generic property for that port is also set.
+""" .
+
+
+ev:inheritsEvent a rdf:Property ;
+	rdfs:domain  lv2:Port ;
+	rdfs:range   lv2:Port ;
+    rdfs:label   "Inherits event type" ;
+    rdfs:comment """
+Indicates that this output port might pass through events that arrived at some
+other input port (or generate an event of the same type as events arriving at
+that input).  The host must always check the stamp type of all outputs when
+connecting an input, but this property should be set whenever it applies.
+""" .
+
+
+ev:supportsTimeStamp a rdf:Property ;
+	rdfs:domain  lv2:Port ;
+	rdfs:range   ev:TimeStamp ;
+    rdfs:label   "Supports time stamp type" ;
+    rdfs:comment """
+Indicates that this port supports or "understands" a certain time stamp type.
+Meaningful only for input ports, the host must never connect a port to an
+event buffer with a time stamp type that isn't supported by the port.
+""" .
+
+
+ev:generatesTimeStamp a rdf:Property ;
+	rdfs:domain  lv2:Port ;
+	rdfs:range   ev:TimeStamp ;
+    rdfs:label   "Outputs time stamp type" ;
+    rdfs:comment """
+Indicates that this port may output a certain time stamp type, regardless of
+the time stamp type of any input ports.  If the port outputs stamps based on
+what type inputs are connected to, this property should not be set (use the
+ev:inheritsTimeStamp property for that).  Hosts MUST check the time_stamp value
+of any output port buffers after a call to connect_port on ANY event input
+port on the plugin.  If the plugin changes the stamp_type field of an output
+event buffer during a call to run(), the plugin must call the
+stamp_type_changed function provided by the host in the LV2_Event_Feature
+struct, if it is non-NULL.
+""" .
+
+
+ev:inheritsTimeStamp a rdf:Property ;
+	rdfs:domain  lv2:Port ;
+	rdfs:range   lv2:Port ;
+    rdfs:label   "Inherits time stamp type" ;
+    rdfs:comment """
+Indicates that this port follows the time stamp type of an input port.
+This property is not necessary, but it should be set for outputs that
+base their output type on an input port so the host can make more sense
+of the plugin and provide a more sensible interface.
+""" .
+
diff --git a/ext/event.lv2/lv2_event.pc.in b/ext/event.lv2/lv2_event.pc.in
new file mode 100644
index 0000000..6d556ef
--- /dev/null
+++ b/ext/event.lv2/lv2_event.pc.in
@@ -0,0 +1,10 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: lv2_event
+Version: @LV2_EVENT_VERSION@
+Description: LV2 events extension
+Libs:
+Cflags: -I${includedir}
diff --git a/ext/event.lv2/manifest.ttl b/ext/event.lv2/manifest.ttl
new file mode 100644
index 0000000..8f17311
--- /dev/null
+++ b/ext/event.lv2/manifest.ttl
@@ -0,0 +1,7 @@
+@prefix lv2:  <http://lv2plug.in/ns/lv2core#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+
+<http://lv2plug.in/ns/ext/event>
+	a lv2:Specification ;
+	rdfs:seeAlso <event.ttl> .
+