media-session: start the midi bridge from the session

spa/include/spa/utils/names.h

@@ -83,9 +83,13 @@ extern "C" {
 									  *  capturing PCM */
 #define SPA_NAME_API_ALSA_PCM_SINK	"api.alsa.pcm.sink"		/**< an alsa Node interface for
 									  *  playback PCM */
-#define SPA_NAME_API_ALSA_MIDI_DEVICE	"api.alsa.midi.device"		/**< an alsa Midi device */
+#define SPA_NAME_API_ALSA_SEQ_DEVICE	"api.alsa.seq.device"		/**< an alsa Midi device */
-#define SPA_NAME_API_ALSA_MIDI_SOURCE	"api.alsa.midi.source"		/**< an alsa Node interface for
+#define SPA_NAME_API_ALSA_SEQ_SOURCE	"api.alsa.seq.source"		/**< an alsa Node interface for
-									  *  capturing midi */
+									  *  capture of midi */
+#define SPA_NAME_API_ALSA_SEQ_SINK	"api.alsa.seq.sink"		/**< an alsa Node interface for
+									  *  playback of midi */
+#define SPA_NAME_API_ALSA_SEQ_BRIDGE	"api.alsa.seq.bridge"		/**< an alsa Node interface for
+									  *  bridging midi ports */
 
 /** keys for bluez5 factory names */
 #define SPA_NAME_API_BLUEZ5_ENUM_DBUS	"api.bluez5.enum.dbus"		/**< a dbus Device interface */

spa/plugins/alsa/alsa-seq-source.c

@@ -36,7 +36,7 @@
 #include <spa/param/audio/format.h>
 #include <spa/pod/filter.h>
 
-#define NAME "alsa-source"
+#define NAME "alsa-bridge"
 
 #include "alsa-seq.h"
 
@@ -946,15 +946,15 @@ impl_enum_interface_info(const struct spa_handle_factory *factory,
 
 static const struct spa_dict_item info_items[] = {
 	{ SPA_KEY_FACTORY_AUTHOR, "Wim Taymans <wim.taymans@gmail.com>" },
-	{ SPA_KEY_FACTORY_DESCRIPTION, "Record midi with the alsa API" },
+	{ SPA_KEY_FACTORY_DESCRIPTION, "Bridge midi ports with the alsa sequencer API" },
 	{ SPA_KEY_FACTORY_USAGE, "["SPA_KEY_API_ALSA_PATH"=<device>]" },
 };
 
 static const struct spa_dict info = SPA_DICT_INIT_ARRAY(info_items);
 
-const struct spa_handle_factory spa_alsa_midi_source_factory = {
+const struct spa_handle_factory spa_alsa_seq_bridge_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
-	SPA_NAME_API_ALSA_MIDI_SOURCE,
+	SPA_NAME_API_ALSA_SEQ_BRIDGE,
 	&info,
 	impl_get_size,
 	impl_init,

spa/plugins/alsa/alsa.c

@@ -30,7 +30,7 @@ extern const struct spa_handle_factory spa_alsa_source_factory;
 extern const struct spa_handle_factory spa_alsa_sink_factory;
 extern const struct spa_handle_factory spa_alsa_udev_factory;
 extern const struct spa_handle_factory spa_alsa_device_factory;
-extern const struct spa_handle_factory spa_alsa_midi_source_factory;
+extern const struct spa_handle_factory spa_alsa_seq_bridge_factory;
 
 SPA_EXPORT
 int spa_handle_factory_enum(const struct spa_handle_factory **factory, uint32_t *index)
@@ -52,7 +52,7 @@ int spa_handle_factory_enum(const struct spa_handle_factory **factory, uint32_t
 		*factory = &spa_alsa_device_factory;
 		break;
 	case 4:
-		*factory = &spa_alsa_midi_source_factory;
+		*factory = &spa_alsa_seq_bridge_factory;
 		break;
 	default:
 		return 0;

src/daemon/pipewire.conf.in

@@ -12,7 +12,7 @@ add-spa-lib api.jack.* jack/libspa-jack
 
 #load-module libpipewire-module-spa-device api.jack.device
 #load-module libpipewire-module-spa-device api.alsa.enum.udev
-load-module libpipewire-module-spa-node api.alsa.midi.source node.name=MIDI-Bridge
+#load-module libpipewire-module-spa-node api.alsa.seq.bridge node.name=MIDI-Bridge
 load-module libpipewire-module-rtkit
 load-module libpipewire-module-protocol-native
 load-module libpipewire-module-spa-node-factory

src/examples/media-session/alsa-monitor.c

@@ -522,6 +522,30 @@ static const struct spa_device_events alsa_udev_events =
 	.object_info = alsa_udev_object_info,
 };
 
+static int alsa_start_midi_bridge(struct impl *impl)
+{
+	struct pw_properties *props;
+	int res = 0;
+
+	props = pw_properties_new(
+			SPA_KEY_FACTORY_NAME, SPA_NAME_API_ALSA_SEQ_BRIDGE,
+			SPA_KEY_NODE_NAME, "Midi-Bridge",
+			NULL);
+
+	impl->midi_bridge = pw_core_proxy_create_object(impl->core_proxy,
+				"spa-node-factory",
+				PW_TYPE_INTERFACE_Node,
+				PW_VERSION_NODE_PROXY,
+				&props->dict,
+                                0);
+
+	if (impl->midi_bridge == NULL) {
+		res = -errno;
+	}
+	return res;
+
+}
+
 static int alsa_start_monitor(struct impl *impl, struct monitor *monitor)
 {
 	struct spa_handle *handle;

src/examples/media-session/media-session.c

@@ -93,6 +93,8 @@ struct impl {
 	struct spa_dbus *dbus;
 	struct spa_dbus_connection *dbus_connection;
 	DBusConnection *conn;
+
+	struct pw_proxy *midi_bridge;
 };
 
 struct object {
@@ -1227,6 +1229,7 @@ static void start_services(struct impl *impl)
 
 	bluez5_start_monitor(impl, &impl->bluez5_monitor);
 	alsa_start_monitor(impl, &impl->alsa_monitor);
+	alsa_start_midi_bridge(impl);
 	v4l2_start_monitor(impl, &impl->v4l2_monitor);
 }