72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
---
|
|
author: "Flávio Schiavoni"
|
|
description: O bladi!
|
|
---
|
|
|
|
#include <signal.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <alsa/asoundlib.h>
|
|
|
|
int keep_walking;
|
|
|
|
static void sigint_handler(int i){
|
|
keep_walking = 0;
|
|
}
|
|
|
|
|
|
int main(int argc, char *argv[]) {
|
|
|
|
int note_time = 1000000; // 1 segundo (em microsegundos)
|
|
|
|
// Pega o Ctrl+C ou signal de Kill para a aplicação.
|
|
signal(SIGINT, &sigint_handler);
|
|
signal(SIGTERM, &sigint_handler);
|
|
keep_walking = 1;
|
|
|
|
// Crio o dispositivo MIDI
|
|
snd_seq_t *seq_handle;
|
|
int portid;
|
|
if (snd_seq_open(&seq_handle, "hw", SND_SEQ_OPEN_DUPLEX, 0) < 0) {
|
|
fprintf(stderr, "Error opening ALSA sequencer.\n");
|
|
exit(1);
|
|
}
|
|
|
|
snd_seq_set_client_name(seq_handle, "My App Midi");
|
|
if ((portid = snd_seq_create_simple_port(seq_handle, "My Midi Port",
|
|
SND_SEQ_PORT_CAP_READ|SND_SEQ_PORT_CAP_SUBS_READ,
|
|
SND_SEQ_PORT_TYPE_APPLICATION)) < 0) {
|
|
fprintf(stderr, "Error creating sequencer port.\n");
|
|
exit(1);
|
|
}
|
|
|
|
snd_seq_event_t ev;
|
|
snd_seq_ev_clear(&ev);
|
|
snd_seq_ev_set_source(&ev, 0);
|
|
snd_seq_ev_set_subs(&ev);
|
|
snd_seq_ev_set_direct(&ev);
|
|
|
|
while (keep_walking) {
|
|
|
|
|
|
// Note on
|
|
snd_seq_ev_set_noteon(&ev, 0, 60, 127);
|
|
snd_seq_event_output(seq_handle, &ev);
|
|
snd_seq_drain_output(seq_handle);
|
|
// Duration
|
|
usleep(note_time);
|
|
|
|
// Note off
|
|
snd_seq_ev_set_noteoff(&ev, 0, 60, 0);
|
|
snd_seq_event_output(seq_handle, &ev);
|
|
snd_seq_drain_output(seq_handle);
|
|
// Duration
|
|
usleep(note_time / 6);
|
|
|
|
}
|
|
|
|
snd_seq_close(seq_handle);
|
|
return 0;
|
|
}
|