aboutsummaryrefslogtreecommitdiffstats
path: root/plugins
diff options
context:
space:
mode:
authorDavid Robillard <d@drobilla.net>2013-02-10 03:21:20 +0000
committerDavid Robillard <d@drobilla.net>2013-02-10 03:21:20 +0000
commit2deb34ec442772f5f68c1818a290748ac5a1ed36 (patch)
tree0e377eb79f909b83c3c69692328df642b86201c5 /plugins
parent401d1e9591633dc5c47ccb8e341b63a423c0ee76 (diff)
downloadlv2-2deb34ec442772f5f68c1818a290748ac5a1ed36.tar.xz
Add lv2:Bank, lv2:Program, and lv2:program for describing programs, including but not limited to MIDI programs.
Diffstat (limited to 'plugins')
-rw-r--r--plugins/eg-midigate.lv2/README.txt10
-rw-r--r--plugins/eg-midigate.lv2/manifest.ttl.in10
-rw-r--r--plugins/eg-midigate.lv2/midigate.c223
-rw-r--r--plugins/eg-midigate.lv2/midigate.ttl80
l---------plugins/eg-midigate.lv2/waf1
-rw-r--r--plugins/eg-midigate.lv2/wscript65
6 files changed, 389 insertions, 0 deletions
diff --git a/plugins/eg-midigate.lv2/README.txt b/plugins/eg-midigate.lv2/README.txt
new file mode 100644
index 0000000..8f4a0f0
--- /dev/null
+++ b/plugins/eg-midigate.lv2/README.txt
@@ -0,0 +1,10 @@
+== MIDI Gate ==
+
+This plugin demonstrates:
+
+ * Receiving MIDI input
+
+ * Processing audio based on MIDI events with sample accuracy
+
+ * Supporting MIDI programs which the host can control/automate, or present a
+ user interface for with human readable labels
diff --git a/plugins/eg-midigate.lv2/manifest.ttl.in b/plugins/eg-midigate.lv2/manifest.ttl.in
new file mode 100644
index 0000000..d32f1dc
--- /dev/null
+++ b/plugins/eg-midigate.lv2/manifest.ttl.in
@@ -0,0 +1,10 @@
+# The manifest.ttl file follows the same template as the previous example.
+
+@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix ui: <http://lv2plug.in/ns/extensions/ui#> .
+
+<http://lv2plug.in/plugins/eg-midigate>
+ a lv2:Plugin ;
+ lv2:binary <midigate@LIB_EXT@> ;
+ rdfs:seeAlso <midigate.ttl> .
diff --git a/plugins/eg-midigate.lv2/midigate.c b/plugins/eg-midigate.lv2/midigate.c
new file mode 100644
index 0000000..3b74bfc
--- /dev/null
+++ b/plugins/eg-midigate.lv2/midigate.c
@@ -0,0 +1,223 @@
+/*
+ Copyright 2013 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.
+*/
+
+#include <stdio.h>
+
+#include <math.h>
+#include <stdlib.h>
+
+#include "lv2/lv2plug.in/ns/ext/atom/atom.h"
+#include "lv2/lv2plug.in/ns/ext/atom/util.h"
+#include "lv2/lv2plug.in/ns/ext/midi/midi.h"
+#include "lv2/lv2plug.in/ns/ext/urid/urid.h"
+#include "lv2/lv2plug.in/ns/lv2core/lv2.h"
+
+#define MIDIGATE_URI "http://lv2plug.in/plugins/eg-midigate"
+
+typedef enum {
+ MIDIGATE_CONTROL = 0,
+ MIDIGATE_IN = 1,
+ MIDIGATE_OUT = 2
+} PortIndex;
+
+typedef struct {
+ // Port buffers
+ const LV2_Atom_Sequence* control;
+ const float* in;
+ float* out;
+
+ // Features
+ LV2_URID_Map* map;
+
+ struct {
+ LV2_URID midi_MidiEvent;
+ } uris;
+
+ unsigned n_active_notes;
+ unsigned program;
+} Midigate;
+
+static LV2_Handle
+instantiate(const LV2_Descriptor* descriptor,
+ double rate,
+ const char* bundle_path,
+ const LV2_Feature* const* features)
+{
+ /** Scan features array for the URID feature we need. */
+ LV2_URID_Map* map = NULL;
+ for (int i = 0; features[i]; ++i) {
+ if (!strcmp(features[i]->URI, LV2_URID__map)) {
+ map = (LV2_URID_Map*)features[i]->data;
+ break;
+ }
+ }
+ if (!map) {
+ /**
+ No URID feature given. This is a host bug since we require this
+ feature, but should be handled gracefully anyway.
+ */
+ return NULL;
+ }
+
+ Midigate* self = (Midigate*)calloc(1, sizeof(Midigate));
+ self->map = map;
+ self->uris.midi_MidiEvent = map->map(map->handle, LV2_MIDI__MidiEvent);
+
+ return (LV2_Handle)self;
+}
+
+static void
+connect_port(LV2_Handle instance,
+ uint32_t port,
+ void* data)
+{
+ Midigate* self = (Midigate*)instance;
+
+ switch ((PortIndex)port) {
+ case MIDIGATE_CONTROL:
+ self->control = (const LV2_Atom_Sequence*)data;
+ break;
+ case MIDIGATE_IN:
+ self->in = (const float*)data;
+ break;
+ case MIDIGATE_OUT:
+ self->out = (float*)data;
+ break;
+ }
+}
+
+static void
+activate(LV2_Handle instance)
+{
+ Midigate* self = (Midigate*)instance;
+ self->n_active_notes = 0;
+ self->program = 0;
+}
+
+/**
+ A function to write a chunk of output, to be called from run(). If the gate
+ is high, then the input will be passed through for this chunk, otherwise
+ silence is written.
+*/
+static void
+write_output(Midigate* self, uint32_t offset, uint32_t len)
+{
+ const bool active = (self->program == 0)
+ ? (self->n_active_notes > 0)
+ : (self->n_active_notes == 0);
+ if (active) {
+ memcpy(self->out + offset, self->in + offset, len * sizeof(float));
+ } else {
+ memset(self->out + offset, 0, len * sizeof(float));
+ }
+}
+
+/**
+ This plugin works through the cycle in chunks starting at offset zero. The
+ +offset+ represents the current time within this this cycle, so
+ the output from 0 to +offset+ has already been written.
+
+ MIDI events are read in a loop. In each iteration, the number of active
+ notes (on note on and note off) or the program (on program change) is
+ updated, then the output is written up until the current event time. Then
+ +offset+ is updated and the next event is processed. After the loop the
+ final chunk from the last event to the end of the cycle is emitted.
+
+ This pattern of iterating over input events and writing output along the way
+ is a common idiom for writing sample accurate output based on event input.
+
+ Note that this simple example simply writes input or zero for each sample
+ based on the gate. A serious implementation would need to envelope the
+ transition to avoid aliasing.
+*/
+static void
+run(LV2_Handle instance, uint32_t sample_count)
+{
+ Midigate* self = (Midigate*)instance;
+ uint32_t offset = 0;
+
+ LV2_ATOM_SEQUENCE_FOREACH(self->control, ev) {
+ if (ev->body.type == self->uris.midi_MidiEvent) {
+ const uint8_t* const msg = (const uint8_t*)(ev + 1);
+ switch (lv2_midi_message_type(msg)) {
+ case LV2_MIDI_MSG_NOTE_ON:
+ ++self->n_active_notes;
+ break;
+ case LV2_MIDI_MSG_NOTE_OFF:
+ --self->n_active_notes;
+ break;
+ case LV2_MIDI_MSG_PGM_CHANGE:
+ if (msg[1] == 0 || msg[1] == 1) {
+ self->program = msg[1];
+ }
+ break;
+ default: break;
+ }
+ }
+
+ write_output(self, offset, ev->time.frames - offset);
+ offset = ev->time.frames;
+ }
+
+ write_output(self, offset, sample_count - offset);
+}
+
+/**
+ We have no resources to free on deactivation.
+ Note that the next call to activate will re-initialise the state, namely
+ self->n_active_notes, so there is no need to do so here.
+*/
+static void
+deactivate(LV2_Handle instance)
+{}
+
+static void
+cleanup(LV2_Handle instance)
+{
+ free(instance);
+}
+
+/**
+ This plugin also has no extension data to return.
+*/
+static const void*
+extension_data(const char* uri)
+{
+ return NULL;
+}
+
+static const LV2_Descriptor descriptor = {
+ MIDIGATE_URI,
+ instantiate,
+ connect_port,
+ activate,
+ run,
+ deactivate,
+ cleanup,
+ 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-midigate.lv2/midigate.ttl b/plugins/eg-midigate.lv2/midigate.ttl
new file mode 100644
index 0000000..59ac815
--- /dev/null
+++ b/plugins/eg-midigate.lv2/midigate.ttl
@@ -0,0 +1,80 @@
+# The same set of namespace prefixes with two additions for LV2 extensions this
+# plugin uses: atom and urid.
+
+@prefix atom: <http://lv2plug.in/ns/ext/atom#> .
+@prefix doap: <http://usefulinc.com/ns/doap#> .
+@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
+@prefix midi: <http://lv2plug.in/ns/ext/midi#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix urid: <http://lv2plug.in/ns/ext/urid#> .
+
+<http://lv2plug.in/plugins/eg-midigate>
+ a lv2:Plugin ;
+ doap:name "Example MIDI Gate" ;
+ doap:license <http://opensource.org/licenses/isc> ;
+ lv2:project <http://lv2plug.in/ns/lv2> ;
+ lv2:requiredFeature urid:map ;
+ lv2:optionalFeature lv2:hardRTCapable ;
+# Describe program banks so the host can automate and/or present a user
+# interface. Describing supported programs (or any other MIDI event) is not
+# required, but is a good idea since it allows hosts to make better use of
+# plugins. This plugin has a single bank of two programs, which have a
+# (mandatory) label, and an (optional) comment to describe their meaning in
+# more detail.
+#
+# Both programs and the bank have an index, which corresponds to the MIDI bank
+# and program numbers that will activate them. Since there are other ways to
+# change programs (not used here), an index is not strictly required, but must
+# be present to support program changes from MIDI.
+ lv2:bank [
+ rdfs:label "Default" ;
+ lv2:index 0 ;
+ lv2:program [
+ lv2:index 0 ;
+ rdfs:label "Normal" ;
+ rdfs:comment "Input is passed through if notes are active."
+ ] , [
+ lv2:index 1 ;
+ rdfs:label "Inverted" ;
+ rdfs:comment "Input is passed through if no notes are active."
+ ]
+ ] ;
+# This plugin has three ports. There is an audio input and output as before,
+# as well as a new AtomPort. An AtomPort buffer contains an Atom, which is a
+# generic container for any type of data. In this case, we want to receive
+# MIDI events, so the (mandatory) +atom:bufferType+ is atom:Sequence, which is
+# a series of events with time stamps.
+#
+# Events themselves are also generic and can contain any type of data, but in
+# this case we are only interested in MIDI events. The (optional)
+# +atom:supports+ property describes which event types are supported. Though
+# not required, this information should always be given so the host knows what
+# types of event it can expect the plugin to understand.
+#
+# The (optional) +lv2:designation+ of this port is +lv2:control+, which
+# indicates that this is the "main" control port where the host should send
+# events it expects to configure the plugin, in this case changing the MIDI
+# program. This is necessary since it is possible to have several MIDI input
+# ports, though typically it is best to have one.
+ lv2:port [
+ a lv2:InputPort ,
+ atom:AtomPort ;
+ atom:bufferType atom:Sequence ;
+ atom:supports midi:MidiEvent ;
+ lv2:designation lv2:control ;
+ lv2:index 0 ;
+ lv2:symbol "control" ;
+ lv2:name "Control"
+ ] , [
+ a lv2:AudioPort ,
+ lv2:InputPort ;
+ lv2:index 1 ;
+ lv2:symbol "in" ;
+ lv2:name "In"
+ ] , [
+ a lv2:AudioPort ,
+ lv2:OutputPort ;
+ lv2:index 2 ;
+ lv2:symbol "out" ;
+ lv2:name "Out"
+ ] .
diff --git a/plugins/eg-midigate.lv2/waf b/plugins/eg-midigate.lv2/waf
new file mode 120000
index 0000000..59a1ac9
--- /dev/null
+++ b/plugins/eg-midigate.lv2/waf
@@ -0,0 +1 @@
+../../waf \ No newline at end of file
diff --git a/plugins/eg-midigate.lv2/wscript b/plugins/eg-midigate.lv2/wscript
new file mode 100644
index 0000000..44336af
--- /dev/null
+++ b/plugins/eg-midigate.lv2/wscript
@@ -0,0 +1,65 @@
+#!/usr/bin/env python
+from waflib.extras import autowaf as autowaf
+import re
+
+# Variables for 'waf dist'
+APPNAME = 'eg-midigate.lv2'
+VERSION = '1.0.0'
+
+# Mandatory variables
+top = '.'
+out = 'build'
+
+def options(opt):
+ opt.load('compiler_c')
+ autowaf.set_options(opt)
+
+def configure(conf):
+ conf.load('compiler_c')
+ autowaf.configure(conf)
+ autowaf.set_c99_mode(conf)
+ autowaf.display_header('Midigate Configuration')
+
+ if not autowaf.is_child():
+ autowaf.check_pkg(conf, 'lv2', uselib_store='LV2')
+
+ autowaf.display_msg(conf, 'LV2 bundle directory', conf.env.LV2DIR)
+ print('')
+
+def build(bld):
+ bundle = 'eg-midigate.lv2'
+
+ # Make a pattern for shared objects without the 'lib' prefix
+ module_pat = re.sub('^lib', '', bld.env.cshlib_PATTERN)
+ module_ext = module_pat[module_pat.rfind('.'):]
+
+ # Build manifest.ttl by substitution (for portable lib extension)
+ bld(features = 'subst',
+ source = 'manifest.ttl.in',
+ target = '%s/%s' % (bundle, 'manifest.ttl'),
+ install_path = '${LV2DIR}/%s' % bundle,
+ LIB_EXT = module_ext)
+
+ # Copy other data files to build bundle (build/eg-midigate.lv2)
+ for i in ['midigate.ttl']:
+ bld(features = 'subst',
+ is_copy = True,
+ source = i,
+ target = '%s/%s' % (bundle, i),
+ install_path = '${LV2DIR}/%s' % bundle)
+
+ # Use LV2 headers from parent directory if building as a sub-project
+ includes = None
+ if autowaf.is_child:
+ includes = '../..'
+
+ # Build plugin library
+ obj = bld(features = 'c cshlib',
+ source = 'midigate.c',
+ name = 'midigate',
+ target = '%s/midigate' % bundle,
+ install_path = '${LV2DIR}/%s' % bundle,
+ uselib = 'LV2',
+ includes = includes)
+ obj.env.cshlib_PATTERN = module_pat
+