1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
#include <stdio.h>
#include <stdlib.h>
#include <alloca.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");
snd_seq_t *seq_handle;
if (snd_seq_open(&seq_handle, "default", SND_SEQ_OPEN_DUPLEX, 0) < 0) {
fprintf(stderr, "Error opening ALSA sequencer.\n");
exit(1);
}
if (snd_seq_set_client_name(seq_handle, CLIENT_NAME) < 0) {
fprintf(stderr, "Could not set up client name.\n");
exit(1);
}
if (snd_seq_create_simple_port(seq_handle, CLIENT_NAME,
SND_SEQ_PORT_CAP_WRITE |
SND_SEQ_PORT_CAP_SUBS_WRITE,
SND_SEQ_PORT_TYPE_MIDI_GENERIC |
SND_SEQ_PORT_TYPE_APPLICATION) < 0) {
fprintf(stderr, "Error creating sequencer port.\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 (err < 0) {
fprintf(stderr, "Cannot connect from port %d:%d - %s", ports[i].client, ports[i].port, snd_strerror(err));
exit(1);
}
}
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;
size_t 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;
}
|
