Add sampler example plugin

6 files changed, 472 insertions, 0 deletions

diff --git a/plugins/eg-sampler.lv2/manifest.ttl b/plugins/eg-sampler.lv2/manifest.ttl
new file mode 100644
index 0000000..f6ab02d
--- /dev/null
+++ b/plugins/eg-sampler.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/plugins/eg-sampler>
+	a lv2:Plugin ;
+	lv2:binary <sampler.so> ;
+	rdfs:seeAlso <sampler.ttl> .
diff --git a/plugins/eg-sampler.lv2/monosample.wav b/plugins/eg-sampler.lv2/monosample.wav
new file mode 100644
index 0000000..df3b478
--- /dev/null
+++ b/plugins/eg-sampler.lv2/monosample.wav
diff --git a/plugins/eg-sampler.lv2/sampler.c b/plugins/eg-sampler.lv2/sampler.c
new file mode 100644
index 0000000..173f844
--- /dev/null
+++ b/plugins/eg-sampler.lv2/sampler.c
@@ -0,0 +1,354 @@
+/*
+  LV2 Sampler Example Plugin
+  Copyright 2011 Gabriel M. Beddingfield <gabriel@teuton.org>,
+  James Morris <jwm.art.net@gmail.com>,
+  David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+/**
+   @file sampler.c Sampler Plugin
+ 
+   A simple example of an LV2 sampler that dynamically loads samples (based on
+   incoming events) and also triggers their playback (based on incoming MIDI
+   note events).  The sample must be monophonic.
+ 
+   So that the runSampler() method stays real-time safe, the plugin creates a
+   worker thread (worker_thread_main) that listens for file loading events.  It
+   loads everything in plugin->pending_samp and then signals the runSampler()
+   that it's time to install it.  runSampler() just has to swap pointers... so
+   the change happens very fast and atomically.
+*/
+
+#include <assert.h>
+#include <math.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <pthread.h>
+
+#include <sndfile.h>
+
+#include "lv2/lv2plug.in/ns/lv2core/lv2.h"
+#include "lv2/lv2plug.in/ns/ext/event/event-helpers.h"
+#include "lv2/lv2plug.in/ns/ext/uri-map/uri-map.h"
+
+#define SAMPLER_URI    "http://lv2plug.in/plugins/eg-sampler"
+#define MIDI_EVENT_URI "http://lv2plug.in/ns/ext/midi#MidiEvent"
+#define STRING_BUF     8192
+
+enum {
+	SAMPLER_CONTROL = 0,
+	SAMPLER_OUT     = 1
+};
+
+static const char* default_sample_file = "monosample.wav";
+
+typedef struct {
+	char    filepath[STRING_BUF];
+	SF_INFO info;
+	float*  data;
+} SampleFile;
+
+typedef struct {
+	/* Sample */
+	SampleFile*     samp;
+	SampleFile*     pending_samp;
+	pthread_mutex_t pending_samp_mutex;  /**< Protects pending_samp */
+	pthread_cond_t  pending_samp_cond;   /**< Signaling mechanism */
+	int             pending_sample_ready;
+
+	/* Ports */
+	float*             outputPort;
+	LV2_Event_Buffer*  eventPort;
+	LV2_Event_Feature* event_ref;
+	int                midi_event_id;
+
+	/* Playback state */
+	bool       play;
+	sf_count_t frame;
+
+	/* File loading */
+	pthread_t worker_thread;
+} Sampler;
+
+static void
+handle_load_sample(Sampler* plugin)
+{
+	plugin->pending_sample_ready = 0;
+
+	SF_INFO* const info   = &plugin->pending_samp->info;
+	SNDFILE* const sample = sf_open(plugin->pending_samp->filepath,
+                                    SFM_READ,
+                                    info);
+
+	if (!sample
+	    || !info->frames
+	    || (info->channels != 1)) {
+		fprintf(stderr, "failed to open sample '%s'.\n",
+		        plugin->pending_samp->filepath);
+		return;
+	}
+
+	/* Read data */
+	float* const data = malloc(sizeof(float) * info->frames);
+	plugin->pending_samp->data = data;
+
+	if (!data) {
+		fprintf(stderr, "failed to allocate memory for sample.\n");
+		return;
+	}
+
+	sf_seek(sample, 0ul, SEEK_SET);
+	sf_read_float(sample,
+	              data,
+	              info->frames);
+	sf_close(sample);
+
+	/* Queue the sample for installation on next run() */
+	plugin->pending_sample_ready = 1;
+}
+
+void*
+worker_thread_main(void* arg)
+{
+	Sampler* plugin;
+
+	plugin = (Sampler*)arg;
+
+	pthread_mutex_lock(&plugin->pending_samp_mutex);
+	while (true) {
+		/* Wait for run() to signal that we need to load a sample */
+		pthread_cond_wait(&plugin->pending_samp_cond,
+		                  &plugin->pending_samp_mutex);
+
+        /* Then load it */
+		handle_load_sample(plugin);
+	}
+	pthread_mutex_unlock(&plugin->pending_samp_mutex);
+
+	return 0;
+}
+
+static void
+cleanup(LV2_Handle instance)
+{
+	Sampler* plugin = (Sampler*)instance;
+	pthread_cancel(plugin->worker_thread);
+	pthread_join(plugin->worker_thread, 0);
+
+	free(plugin->samp->data);
+	free(plugin->pending_samp->data);
+	free(plugin->samp);
+	free(plugin->pending_samp);
+	free(instance);
+}
+
+static void
+connect_port(LV2_Handle instance,
+             uint32_t   port,
+             void*      data)
+{
+	Sampler* plugin = (Sampler*)instance;
+
+	switch (port) {
+	case SAMPLER_CONTROL:
+		plugin->eventPort = (LV2_Event_Buffer*)data;
+		break;
+	case SAMPLER_OUT:
+        plugin->outputPort = (float*)data;
+		break;
+	default:
+		break;
+	}
+}
+
+static LV2_Handle
+instantiate(const LV2_Descriptor*     descriptor,
+            double                    rate,
+            const char*               path,
+            const LV2_Feature* const* features)
+{
+	Sampler* plugin = (Sampler*)malloc(sizeof(Sampler));
+	assert(plugin);
+	memset(plugin, 0, sizeof(Sampler));
+
+	plugin->samp = (SampleFile*)malloc(sizeof(SampleFile));
+	assert(plugin->samp);
+	memset(plugin->samp, 0, sizeof(SampleFile));
+	plugin->pending_samp = (SampleFile*)malloc(sizeof(SampleFile));
+	assert(plugin->pending_samp);
+	memset(plugin->pending_samp, 0, sizeof(SampleFile));
+
+	plugin->midi_event_id = -1;
+	plugin->event_ref     = 0;
+
+	/* Initialise mutexes and conditions for the worker thread */
+	if (pthread_mutex_init(&plugin->pending_samp_mutex, 0)) {
+		fprintf(stderr, "Could not initialize next_sample_mutex.\n");
+		goto fail;
+	}
+	if (pthread_cond_init(&plugin->pending_samp_cond, 0)) {
+		fprintf(stderr, "Could not initialize next_sample_waitcond.\n");
+		goto fail;
+	}
+	if (pthread_create(&plugin->worker_thread, 0, worker_thread_main, plugin)) {
+		fprintf(stderr, "Could not initialize worker thread.\n");
+		goto fail;
+	}
+
+	/* Scan host features for event and uri-map */
+	for (int i = 0; features[i]; ++i) {
+		if (strcmp(features[i]->URI, LV2_URI_MAP_URI) == 0) {
+			LV2_URI_Map_Feature*
+                map_feature = (LV2_URI_Map_Feature*)features[i]->data;
+
+			plugin->midi_event_id
+			    = map_feature->uri_to_id(map_feature->callback_data,
+			                             LV2_EVENT_URI, MIDI_EVENT_URI);
+		} else if (strcmp(features[i]->URI, LV2_EVENT_URI) == 0) {
+			plugin->event_ref = (LV2_Event_Feature*)features[i]->data;
+		}
+	}
+
+	if (plugin->midi_event_id == -1) {
+		/* Host does not support uri-map extension */
+		fprintf(stderr, "Host does not support uri-map extension.\n");
+		goto fail;
+	}
+
+	/* Open the default sample file */
+	strncpy(plugin->pending_samp->filepath, path, STRING_BUF);
+	strncat(plugin->pending_samp->filepath,
+	        default_sample_file,
+	        STRING_BUF - strlen(plugin->pending_samp->filepath) );
+	handle_load_sample(plugin);
+
+	return (LV2_Handle)plugin;
+
+fail:
+	free(plugin);
+	return 0;
+}
+
+static void
+run(LV2_Handle instance,
+    uint32_t   sample_count)
+{
+	Sampler*   plugin = (Sampler*)instance;
+	LV2_Event* ev     = NULL;
+
+	sf_count_t start_frame = 0;
+	sf_count_t pos         = 0;
+	float*     output      = plugin->outputPort;
+
+	/* Read incoming events */
+	LV2_Event_Iterator iterator;
+    for (lv2_event_begin(&iterator, plugin->eventPort);
+         lv2_event_is_valid(&iterator);
+         lv2_event_increment(&iterator)) {
+         
+		ev = lv2_event_get(&iterator, NULL);
+
+		if (ev->type == 0) {
+			if (plugin->event_ref) {
+				plugin->event_ref->lv2_event_unref(
+				    plugin->event_ref->callback_data, ev);
+			}
+		} else if (ev->type == plugin->midi_event_id) {
+			uint8_t* const data = (uint8_t* const)(ev + 1);
+
+			if ((data[0] & 0xF0) == 0x90) {
+				start_frame   = ev->frames;
+				plugin->frame = 0;
+				plugin->play  = true;
+			}
+		}
+		/***************************************************
+		 * XXX TODO:                                       *
+		 * ADD CODE HERE TO DETECT AN INCOMING MESSAGE TO  *
+		 * DYNAMICALLY LOAD A SAMPLE                       *
+		 ***************************************************
+		 */
+		else if (0) {
+			/* message to load a sample comes in */
+			/* write filename to plugin->pending_samp->filepath */
+			/* strncpy(plugin->pending_samp->filepath, some_src_string, STRING_BUF); */
+			pthread_cond_signal(&plugin->pending_samp_cond);
+		}
+	}
+
+	/* Render the sample (possibly already in progress) */
+	if (plugin->play) {
+		uint32_t       f  = plugin->frame;
+		const uint32_t lf = plugin->samp->info.frames;
+
+		for (pos = 0; pos < start_frame; ++pos) {
+			output[pos] = 0;
+		}
+
+		for (; pos < sample_count && f < lf; ++pos, ++f) {
+			output[pos] = plugin->samp->data[f];
+		}
+
+		plugin->frame = f;
+
+		if (f == lf) {
+			plugin->play = false;
+		}
+	}
+
+	/* Check if we have a sample pending */
+	if (!plugin->play
+	    && plugin->pending_sample_ready
+	    && pthread_mutex_trylock(&plugin->pending_samp_mutex)) {
+		/* Install the new sample */
+		SampleFile* tmp;
+		tmp                          = plugin->samp;
+		plugin->samp                 = plugin->pending_samp;
+		plugin->pending_samp         = tmp;
+		plugin->pending_sample_ready = 0;
+		free(plugin->pending_samp->data);
+
+		pthread_mutex_unlock(&plugin->pending_samp_mutex);
+	}
+
+	/* Add zeros to end if sample not long enough (or not playing) */
+	for (; pos < sample_count; ++pos) {
+		output[pos] = 0;
+	}
+}
+
+static const LV2_Descriptor descriptor = {
+	SAMPLER_URI,
+	instantiate,
+	connect_port,
+	NULL, // activate,
+	run,
+	NULL, // deactivate,
+	cleanup,
+	NULL, // extension_data
+};
+
+LV2_SYMBOL_EXPORT
+const LV2_Descriptor* lv2_descriptor(uint32_t index)
+{
+    switch (index) {
+	case 0:
+		return &descriptor;
+	default:
+		return NULL;
+	}
+}
diff --git a/plugins/eg-sampler.lv2/sampler.ttl b/plugins/eg-sampler.lv2/sampler.ttl
new file mode 100644
index 0000000..1926652
--- /dev/null
+++ b/plugins/eg-sampler.lv2/sampler.ttl
@@ -0,0 +1,43 @@
+# LV2 Sampler Example Plugin
+# Copyright 2011 Gabriel M. Beddingfield <gabriel@teuton.org>,
+#                James Morris <jwm.art.net@gmail.com>,
+#                David Robillard <d@drobilla.net>
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+@prefix doap: <http://usefulinc.com/ns/doap#> .
+@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
+@prefix lv2ev: <http://lv2plug.in/ns/ext/event#> .
+
+<http://lv2plug.in/plugins/eg-sampler>
+	a lv2:Plugin ;
+	doap:name "Simple Sampler" ;
+	doap:license <http://opensource.org/licenses/isc-license> ;
+	lv2:requiredFeature <http://lv2plug.in/ns/ext/uri-map> ;
+	lv2:optionalFeature lv2:hardRtCapable ,
+		<http://lv2plug.in/ns/ext/event> ;
+	lv2:port [
+		a lv2:InputPort ,
+			lv2ev:EventPort ;
+		lv2ev:supportsEvent <http://lv2plug.in/ns/ext/midi#MidiEvent> ;
+		lv2:index 0 ;
+		lv2:symbol "control" ;
+		lv2:name "Control"
+	] , [
+		a lv2:AudioPort ,
+			lv2:OutputPort ;
+		lv2:index 1 ;
+		lv2:symbol "out" ;
+		lv2:name "Out"
+	] .
diff --git a/plugins/eg-sampler.lv2/waf b/plugins/eg-sampler.lv2/waf
new file mode 120000
index 0000000..59a1ac9
--- /dev/null
+++ b/plugins/eg-sampler.lv2/waf
@@ -0,0 +1 @@
+../../waf
\ No newline at end of file
diff --git a/plugins/eg-sampler.lv2/wscript b/plugins/eg-sampler.lv2/wscript
new file mode 100644
index 0000000..2957ce1
--- /dev/null
+++ b/plugins/eg-sampler.lv2/wscript
@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+import os
+import shutil
+from waflib import Logs
+from waflib.extras import autowaf as autowaf
+
+# Variables for 'waf dist'
+APPNAME = 'eg-sampler.lv2'
+VERSION = '1.0.0'
+
+# Mandatory variables
+top = '.'
+out = 'build'
+
+def options(opt):
+    autowaf.set_options(opt)
+    opt.load('compiler_c')
+
+def configure(conf):
+    autowaf.configure(conf)
+
+    conf.line_just = 51
+    autowaf.display_header('Sampler Configuration')
+    conf.load('compiler_c')
+
+    autowaf.check_header(conf, 'c', 'lv2/lv2plug.in/ns/lv2core/lv2.h')
+    autowaf.check_pkg(conf, 'sndfile', uselib_store='SNDFILE',
+                      atleast_version='1.0.0', mandatory=True)
+
+    conf.env.append_value('CFLAGS', '-std=c99')
+
+    # Set env['pluginlib_PATTERN']
+    pat = conf.env['cshlib_PATTERN']
+    if pat.startswith('lib'):
+        pat = pat[3:]
+    conf.env['pluginlib_PATTERN'] = pat
+    conf.env['pluginlib_EXT'] = pat[pat.rfind('.'):]
+
+    autowaf.display_msg(conf, "LV2 bundle directory",
+                        conf.env['LV2DIR'])
+    print('')
+
+def build(bld):
+    bundle = 'eg-sampler.lv2'
+
+    # Copy data files to build bundle (build/eg-sampler.lv2)
+    for i in [ 'sampler.ttl', 'manifest.ttl', 'monosample.wav' ]:
+        bld(rule         = 'cp ${SRC} ${TGT}',
+            source       = i,
+            target       = bld.path.get_bld().make_node('%s/%s' % (bundle, i)),
+            install_path = '${LV2DIR}/%s' % bundle)
+
+    # Create a build environment that builds module-style library names
+    # e.g. eg-sampler.so instead of libeg-sampler.so
+    # Note for C++ you must set cxxshlib_PATTERN instead
+    penv                   = bld.env.derive()
+    penv['cshlib_PATTERN'] = bld.env['pluginlib_PATTERN']
+
+    # Build plugin library
+    obj = bld(features     = 'c cshlib',
+              env          = penv,
+              source       = 'sampler.c',
+              name         = 'sampler',
+              target       = '%s/sampler' % bundle,
+              install_path = '${LV2DIR}/%s' % bundle,
+              use          = 'SNDFILE')
+