example-clients/midisine.c

   1 /*
   2     Copyright (C) 2004 Ian Esten
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17 */
  18
  19 #include <stdio.h>
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <signal.h>
  25 #include <math.h>
  26
  27 #include <jack/jack.h>
  28 #include <jack/midiport.h>
  29
  30 jack_port_t *input_port;
  31 jack_port_t *output_port;
  32 jack_default_audio_sample_t ramp=0.0;
  33 jack_default_audio_sample_t note_on;
  34 unsigned char note = 0;
  35 jack_default_audio_sample_t note_frqs[128];
  36
  37 jack_client_t *client;
  38
  39 static void signal_handler(int sig)
  40 {
  41         jack_client_close(client);
  42         fprintf(stderr, "signal received, exiting ...\n");
  43         exit(0);
  44 }
  45
  46 static void calc_note_frqs(jack_default_audio_sample_t srate)
  47 {
  48         int i;
  49         for(i=0; i<128; i++)
  50         {
  51                 note_frqs[i] = (2.0 * 440.0 / 32.0) * pow(2, (((jack_default_audio_sample_t)i - 9.0) / 12.0)) / srate;
  52         }
  53 }
  54
  55 static int process(jack_nframes_t nframes, void *arg)
  56 {
  57         int i;
  58         void* port_buf = jack_port_get_buffer(input_port, nframes);
  59         jack_default_audio_sample_t *out = (jack_default_audio_sample_t *) jack_port_get_buffer (output_port, nframes);
  60         jack_midi_event_t in_event;
  61         jack_nframes_t event_index = 0;
  62         jack_nframes_t event_count = jack_midi_get_event_count(port_buf);
  63         if(event_count > 1)
  64         {
  65                 printf(" midisine: have %d events\n", event_count);
  66                 for(i=0; i<event_count; i++)
  67                 {
  68                         jack_midi_event_get(&in_event, port_buf, i);
  69                         printf("    event %d time is %d. 1st byte is 0x%x\n", i, in_event.time, *(in_event.buffer));
  70                 }
  71 /*              printf("1st byte of 1st event addr is %p\n", in_events[0].buffer);*/
  72         }
  73         jack_midi_event_get(&in_event, port_buf, 0);
  74         for(i = 0; i < nframes; i++)
  75         {
  76                 if ((in_event.time == i) && (event_index < event_count))
  77                 {
  78                         if (((*(in_event.buffer) & 0xf0)) == 0x90)
  79                         {
  80                 /* note on */
  81                 note = *(in_event.buffer + 1);
  82                 if (*(in_event.buffer + 2) == 0) {
  83                     note_on = 0.0;
  84                 } else {
  85                     note_on = (float)(*(in_event.buffer + 2)) / 127.f;
  86                 }
  87                         }
  88                         else if (((*(in_event.buffer)) & 0xf0) == 0x80)
  89                         {
  90                                 /* note off */
  91                                 note = *(in_event.buffer + 1);
  92                                 note_on = 0.0;
  93                         }
  94                         event_index++;
  95                         if(event_index < event_count)
  96                                 jack_midi_event_get(&in_event, port_buf, event_index);
  97                 }
  98                 ramp += note_frqs[note];
  99                 ramp = (ramp > 1.0) ? ramp - 2.0 : ramp;
 100                 out[i] = note_on*sin(2*M_PI*ramp);
 101         }
 102         return 0;
 103 }
 104
 105 static int srate(jack_nframes_t nframes, void *arg)
 106 {
 107         printf("the sample rate is now %" PRIu32 "/sec\n", nframes);
 108         calc_note_frqs((jack_default_audio_sample_t)nframes);
 109         return 0;
 110 }
 111
 112 static void jack_shutdown(void *arg)
 113 {
 114     fprintf(stderr, "JACK shut down, exiting ...\n");
 115         exit(1);
 116 }
 117
 118 int main(int narg, char **args)
 119 {
 120         if ((client = jack_client_open("midisine", JackNullOption, NULL)) == 0)
 121         {
 122                 fprintf(stderr, "JACK server not running?\n");
 123                 return 1;
 124         }
 125
 126         calc_note_frqs(jack_get_sample_rate (client));
 127
 128         jack_set_process_callback (client, process, 0);
 129
 130         jack_set_sample_rate_callback (client, srate, 0);
 131
 132         jack_on_shutdown (client, jack_shutdown, 0);
 133
 134         input_port = jack_port_register (client, "midi_in", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
 135         output_port = jack_port_register (client, "audio_out", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
 136
 137         if (jack_activate (client))
 138         {
 139                 fprintf(stderr, "cannot activate client");
 140                 return 1;
 141         }
 142
 143     /* install a signal handler to properly quits jack client */
 144     signal(SIGQUIT, signal_handler);
 145         signal(SIGTERM, signal_handler);
 146         signal(SIGHUP, signal_handler);
 147         signal(SIGINT, signal_handler);
 148
 149         /* run until interrupted */
 150         while(1) {
 151                 sleep(1);
 152         }
 153         jack_client_close(client);
 154         exit (0);
 155 }
 156