Commit 0eeada4

Wrapping up example 4 with reading MIDI

Author	Mitja Felicijan <mitja.felicijan@gmail.com>	2024-10-07 19:18:06 +0200
Committer	Mitja Felicijan <mitja.felicijan@gmail.com>	2024-10-07 19:18:06 +0200
Commit	`0eeada47529c98b7a3b213146ec4552f02aa9038` (patch)

-rw-r--r-- example4.c 74

1 files changed, 73 insertions, 1 deletions


#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <alsa/asoundlib.h>
  
#define CLIENT_NAME "ttdaw"
#define MAX_MIDI_PORTS 1
  
static snd_seq_t *seq_handle;
static snd_seq_addr_t *ports;
static int rate = 44100;
static int stop = 0;
  
static void sighandler(int sig ATTRIBUTE_UNUSED) {
	stop = 1;
}
  
int main(void) {
	fprintf(stdout, "Example: Reading MIDI input\n");

		exit(1);
	}
  
	// Connecting ports.
	char *port_name = "28:0";
	ports = realloc(ports, MAX_MIDI_PORTS * sizeof(snd_seq_addr_t));
	if (snd_seq_parse_address(seq_handle, &ports[0], port_name) < 0) {
		fprintf(stderr, "Invalid port %s.\n", port_name);
		exit(1);
	}
  
	// Listing assigned ports.
	fprintf(stdout, "Ports:\n");
	for (int j = 0; j < MAX_MIDI_PORTS; j++) {
		fprintf(stdout, " client: %d, port: %d\n", ports[j].client, ports[j].port);
	}
  
	// Connecting ports.
	for (int i = 0; i < MAX_MIDI_PORTS; ++i) {
		int err = snd_seq_connect_from(seq_handle, 0, ports[i].client, ports[i].port);

		}
	}
  
	if (snd_seq_nonblock(seq_handle, 1) < 0) {
		fprintf(stderr, "Set nonblock mode failed.");
		exit(1);
	}
  
	signal(SIGINT, sighandler);
	signal(SIGTERM, sighandler);
  
	// Reading MIDI device.
	struct pollfd *pfds;
	int npfds;
  
	npfds = snd_seq_poll_descriptors_count(seq_handle, POLLIN);
	pfds = alloca(sizeof(*pfds) * npfds);
  
	for (;;) {
		snd_seq_poll_descriptors(seq_handle, pfds, npfds, POLLIN);
		if (poll(pfds, npfds, -1) < 0) {
			break;
		}
  
		for (;;) {
			snd_seq_event_t *ev;
  
			if (snd_seq_event_input(seq_handle, &ev) < 0) {
				break;
			}
  
			if (ev) {
				switch (ev->type) {
					case SND_SEQ_EVENT_NOTEON:
						printf("%3d:%-3dNote on  %2d, note %d, velocity: %3d\n",
								ev->source.client, ev->source.port,
								ev->data.note.channel,
								ev->data.note.note,
								ev->data.note.velocity);
						break;
  
					case SND_SEQ_EVENT_NOTEOFF:
						printf("%3d:%-3dNote off\t%2d, note %d\n",
								ev->source.client, ev->source.port,
								ev->data.note.channel,
								ev->data.note.note);
						break;
  
  
				} 
			}
		}
  
		fflush(stdout);
  
		if (stop) {
			break;
		}
	}
  
	fprintf(stdout, "Finishing up\n");
	snd_seq_close(seq_handle);
	return 0;
}


diff --git a/example4.c b/example4.c
1	#include <stdio.h>	1	#include <stdio.h>
2	#include <stdlib.h>	2	#include <stdlib.h>
		3	#include <signal.h>
3	#include <alsa/asoundlib.h>	4	#include <alsa/asoundlib.h>
4		5
5	#define CLIENT_NAME "ttdaw"	6	#define CLIENT_NAME "ttdaw"
6	#define MAX_MIDI_PORTS 4	7	#define MAX_MIDI_PORTS 1
7		8
8	static snd_seq_t *seq_handle;	9	static snd_seq_t *seq_handle;
9	static snd_seq_addr_t *ports;	10	static snd_seq_addr_t *ports;
10	static int rate = 44100;	11	static int rate = 44100;
		12	static int stop = 0;
		13
		14	static void sighandler(int sig ATTRIBUTE_UNUSED) {
		15	stop = 1;
		16	}
11		17
12	int main(void) {	18	int main(void) {
13	fprintf(stdout, "Example: Reading MIDI input\n");	19	fprintf(stdout, "Example: Reading MIDI input\n");
...
33	exit(1);	39	exit(1);
34	}	40	}
35		41
		42	// Connecting ports.
36	char *port_name = "28:0";	43	char *port_name = "28:0";
		44	ports = realloc(ports, MAX_MIDI_PORTS * sizeof(snd_seq_addr_t));
37	if (snd_seq_parse_address(seq_handle, &ports[0], port_name) < 0) {	45	if (snd_seq_parse_address(seq_handle, &ports[0], port_name) < 0) {
38	fprintf(stderr, "Invalid port %s.\n", port_name);	46	fprintf(stderr, "Invalid port %s.\n", port_name);
39	exit(1);	47	exit(1);
40	}	48	}
41		49
		50	// Listing assigned ports.
		51	fprintf(stdout, "Ports:\n");
		52	for (int j = 0; j < MAX_MIDI_PORTS; j++) {
		53	fprintf(stdout, " client: %d, port: %d\n", ports[j].client, ports[j].port);
		54	}
		55
42	// Connecting ports.	56	// Connecting ports.
43	for (int i = 0; i < MAX_MIDI_PORTS; ++i) {	57	for (int i = 0; i < MAX_MIDI_PORTS; ++i) {
44	int err = snd_seq_connect_from(seq_handle, 0, ports[i].client, ports[i].port);	58	int err = snd_seq_connect_from(seq_handle, 0, ports[i].client, ports[i].port);
...
48	}	62	}
49	}	63	}
50		64
		65	if (snd_seq_nonblock(seq_handle, 1) < 0) {
		66	fprintf(stderr, "Set nonblock mode failed.");
		67	exit(1);
		68	}
		69
		70	signal(SIGINT, sighandler);
		71	signal(SIGTERM, sighandler);
		72
		73	// Reading MIDI device.
		74	struct pollfd *pfds;
		75	int npfds;
		76
		77	npfds = snd_seq_poll_descriptors_count(seq_handle, POLLIN);
		78	pfds = alloca(sizeof(pfds) npfds);
		79
		80	for (;;) {
		81	snd_seq_poll_descriptors(seq_handle, pfds, npfds, POLLIN);
		82	if (poll(pfds, npfds, -1) < 0) {
		83	break;
		84	}
		85
		86	for (;;) {
		87	snd_seq_event_t *ev;
		88
		89	if (snd_seq_event_input(seq_handle, &ev) < 0) {
		90	break;
		91	}
		92
		93	if (ev) {
		94	switch (ev->type) {
		95	case SND_SEQ_EVENT_NOTEON:
		96	printf("%3d:%-3dNote on %2d, note %d, velocity: %3d\n",
		97	ev->source.client, ev->source.port,
		98	ev->data.note.channel,
		99	ev->data.note.note,
		100	ev->data.note.velocity);
		101	break;
		102
		103	case SND_SEQ_EVENT_NOTEOFF:
		104	printf("%3d:%-3dNote off\t%2d, note %d\n",
		105	ev->source.client, ev->source.port,
		106	ev->data.note.channel,
		107	ev->data.note.note);
		108	break;
		109
		110
		111	}
		112	}
		113	}
		114
		115	fflush(stdout);
		116
		117	if (stop) {
		118	break;
		119	}
		120	}
		121
		122	fprintf(stdout, "Finishing up\n");
51	snd_seq_close(seq_handle);	123	snd_seq_close(seq_handle);
52	return 0;	124	return 0;
53	}	125	}
...