mirror of
git://projects.qi-hardware.com/wernermisc.git
synced 2024-11-15 11:24:59 +02:00
111 lines
2.2 KiB
C
111 lines
2.2 KiB
C
/*
|
|
* midigen.c - MIDI traffic generator
|
|
*
|
|
* Written 2011 by Werner Almesberger
|
|
* Copyright 2011 Werner Almesberger
|
|
*
|
|
* 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; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*/
|
|
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <sys/time.h>
|
|
#include <alsa/asoundlib.h>
|
|
|
|
|
|
#define NAME "midigen"
|
|
|
|
|
|
static void send_cc(snd_seq_t *midi, snd_seq_event_t *ev, int chan)
|
|
{
|
|
static unsigned v = 0;
|
|
|
|
snd_seq_ev_set_controller(ev, chan, (v >> 7) & 127, v & 127);
|
|
v++;
|
|
snd_seq_event_output(midi, ev);
|
|
snd_seq_drain_output(midi);
|
|
}
|
|
|
|
|
|
static void generate(snd_seq_t *midi, int port, int chan, int t_s, int t_us)
|
|
{
|
|
snd_seq_event_t ev;
|
|
struct timeval next, now;
|
|
int dt_us;
|
|
|
|
snd_seq_ev_clear(&ev);
|
|
snd_seq_ev_set_source(&ev, port);
|
|
snd_seq_ev_set_subs(&ev);
|
|
snd_seq_ev_set_direct(&ev);
|
|
|
|
gettimeofday(&next, NULL);
|
|
while (1) {
|
|
next.tv_sec += t_s;
|
|
next.tv_usec += t_us;
|
|
if (next.tv_usec > 999999) {
|
|
next.tv_sec++;
|
|
next.tv_usec -= 1000000;
|
|
}
|
|
gettimeofday(&now, NULL);
|
|
dt_us = (next.tv_sec-now.tv_sec)*1000000+
|
|
next.tv_usec-now.tv_usec;
|
|
if (dt_us > 0)
|
|
usleep(dt_us);
|
|
send_cc(midi, &ev, chan);
|
|
}
|
|
}
|
|
|
|
static void usage(const char *name)
|
|
{
|
|
fprintf(stderr, "usage: %s [-c channel] rate_hz\n", name);
|
|
exit(1);
|
|
}
|
|
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
snd_seq_t *midi;
|
|
int c;
|
|
int chan = 0, t_us;
|
|
int port;
|
|
|
|
while ((c = getopt(argc, argv, "c:")) != EOF)
|
|
switch (c) {
|
|
case 'c':
|
|
chan = atoi(optarg);
|
|
break;
|
|
default:
|
|
usage(*argv);
|
|
}
|
|
|
|
switch (argc-optind) {
|
|
case 1:
|
|
t_us = 1000000/atof(argv[optind]);
|
|
break;
|
|
default:
|
|
usage(*argv);
|
|
}
|
|
|
|
if (snd_seq_open(&midi, "hw", SND_SEQ_OPEN_OUTPUT,0) < 0) {
|
|
fprintf(stderr, "can't open ALSA sequencer\n");
|
|
exit(1);
|
|
}
|
|
snd_seq_set_client_name(midi, NAME);
|
|
port = snd_seq_create_simple_port(midi, NAME,
|
|
SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ,
|
|
SND_SEQ_PORT_TYPE_APPLICATION);
|
|
if (port < 0) {
|
|
fprintf(stderr, "can't create sequencer port\n");
|
|
exit(1);
|
|
}
|
|
|
|
generate(midi, port, chan, t_us/1000000, t_us % 1000000);
|
|
|
|
return 0;
|
|
}
|