Import jack1 alsa_midi driver as internal client

Signed-off-by: falkTX <falktx@falktx.com>

Author: falkTX

meson.build

@@ -10,7 +10,7 @@ os = build_machine.system()
 cc = meson.get_compiler('c')
 
 alsa_required = false
-if get_option('alsa_in_out').enabled() or get_option('zalsa').enabled()
+if get_option('alsa_in_out').enabled() or get_option('alsa_midi').enabled() or get_option('zalsa').enabled()
   alsa_required = true
 endif
 
@@ -144,6 +144,13 @@ if get_option('alsa_in_out').enabled() or (
   build_alsa_in_out = true
 endif
 
+build_alsa_midi = false
+if get_option('alsa_midi').enabled() or (
+  get_option('alsa_midi').auto() and dep_alsa.found() and has_jack2_internal_client
+)
+  build_alsa_midi = true
+endif
+
 build_jack_net = false
 if get_option('jack_net').enabled() or (get_option('jack_net').auto() and lib_jacknet_dep.found())
   build_jack_net = true
@@ -178,6 +185,7 @@ endif
 
 
 message('Build alsa_in and alsa_out executables: ' + build_alsa_in_out.to_string())
+message('Build alsa_midi internal client: ' + build_alsa_midi.to_string())
 message('Build jack_net_master and jack_net_slave executables: ' + build_jack_net.to_string())
 message('Build jack_netsource executable: ' + build_jack_netsource.to_string())
 if build_jack_netsource

meson_options.txt

@@ -1,4 +1,5 @@
 option('alsa_in_out', type: 'feature', value: 'auto', description: 'Build the alsa_in and alsa_out executables (default: auto)')
+option('alsa_midi', type: 'feature', value: 'auto', description: 'Build the alsa_midi internal client (default: auto)')
 option('jack_net', type: 'feature', value: 'auto', description: 'Build the jack_net_master and jack_net_slave executables (default: auto)')
 option('jack_netsource', type: 'feature', value: 'auto', description: 'Build the jack_netsource executable (default: auto)')
 option('jack_rec', type: 'feature', value: 'auto', description: 'Build the jack_rec executable (default: auto)')

tools/alsa_midi/a2j.h

@@ -0,0 +1,139 @@
+/* -*- Mode: C ; c-basic-offset: 2 -*- */
+/*
+ * ALSA SEQ < - > JACK MIDI bridge
+ *
+ * Copyright (c) 2006,2007 Dmitry S. Baikov <c0ff@konstruktiv.org>
+ * Copyright (c) 2007,2008,2009 Nedko Arnaudov <nedko@arnaudov.name>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#ifndef __jack_alsa_midi_h__
+#define __jack_alsa_midi_h__
+
+#include <stdbool.h>
+#include <semaphore.h>
+#include <jack/midiport.h>
+#include <jack/ringbuffer.h>
+
+#ifdef ALSA_MIDI_INTERNAL_CLIENT
+#define JACK_DRIVER_DECL
+typedef struct jack_engine_t jack_engine_t;
+#else
+#include "driver.h"
+#endif
+
+#include "list.h"
+
+#define JACK_INVALID_PORT NULL
+
+#define MAX_PORTS  2048
+#define MAX_EVENT_SIZE 1024
+
+#define PORT_HASH_BITS 4
+#define PORT_HASH_SIZE (1 << PORT_HASH_BITS)
+
+/* Beside enum use, these are indeces for (struct a2j).stream array */
+#define A2J_PORT_CAPTURE   0    // ALSA playback port -> JACK capture port
+#define A2J_PORT_PLAYBACK  1    // JACK playback port -> ALSA capture port
+
+typedef struct a2j_port * a2j_port_hash_t[PORT_HASH_SIZE];
+
+struct alsa_midi_driver;
+
+struct a2j_port {
+	struct a2j_port * next;         /* hash - jack */
+	struct list_head siblings;      /* list - main loop */
+	struct alsa_midi_driver * driver_ptr;
+	bool is_dead;
+	char name[64];
+	snd_seq_addr_t remote;
+	jack_port_t * jack_port;
+
+	jack_ringbuffer_t * inbound_events; // alsa_midi_event_t + data
+	int64_t last_out_time;
+
+	void * jack_buf;
+};
+
+struct a2j_stream {
+	snd_midi_event_t *codec;
+
+	jack_ringbuffer_t *new_ports;
+
+	a2j_port_hash_t port_hash;
+	struct list_head list;
+};
+
+typedef struct alsa_midi_driver {
+	JACK_DRIVER_DECL;
+
+	jack_client_t * jack_client;
+
+	snd_seq_t *seq;
+	pthread_t alsa_input_thread;
+	pthread_t alsa_output_thread;
+	int client_id;
+	int port_id;
+	int queue;
+	bool freewheeling;
+	bool running;
+	bool finishing;
+
+	jack_ringbuffer_t* port_del;            // struct a2j_port*
+	jack_ringbuffer_t* outbound_events;     // struct a2j_delivery_event
+	jack_nframes_t cycle_start;
+
+	sem_t output_semaphore;
+
+	struct a2j_stream stream[2];
+
+} alsa_midi_driver_t;
+
+#define NSEC_PER_SEC ((int64_t)1000 * 1000 * 1000)
+
+struct a2j_alsa_midi_event {
+	int64_t time;
+	int size;
+};
+
+#define MAX_JACKMIDI_EV_SIZE 64
+
+struct a2j_delivery_event {
+	struct list_head siblings;
+
+	/* a jack MIDI event, plus the port its destined for: everything
+	   the ALSA output thread needs to deliver the event. time is
+	   part of the jack_event.
+	 */
+	jack_midi_event_t jack_event;
+	jack_nframes_t time; /* realtime, not offset time */
+	struct a2j_port* port;
+	char midistring[MAX_JACKMIDI_EV_SIZE];
+};
+
+void a2j_error(const char* fmt, ...);
+
+#define A2J_DEBUG
+/*#undef A2J_DEBUG*/
+
+#ifdef A2J_DEBUG
+extern bool a2j_do_debug;
+extern void _a2j_debug(const char* fmt, ...);
+#define a2j_debug(fmt, ...) if (a2j_do_debug) { _a2j_debug ((fmt), ## __VA_ARGS__); }
+#else
+#define a2j_debug(fmt, ...)
+#endif
+
+#endif /* __jack_alsa_midi_h__ */