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 #include <inttypes.h>
  27
  28 #include <jack/jack.h>
  29 #include <jack/midiport.h>
  30
  31 jack_port_t *input_port;
  32 jack_port_t *output_port;
  33 jack_default_audio_sample_t ramp=0.0;
  34 jack_default_audio_sample_t note_on;
  35 unsigned char note = 0;
  36 jack_default_audio_sample_t note_frqs[128];
  37
  38 jack_client_t *client;
  39
  40 static void signal_handler(int sig)
  41 {
  42         jack_client_close(client);
  43         fprintf(stderr, "signal received, exiting ...\n");
  44         exit(0);
  45 }
  46
  47 static void calc_note_frqs(jack_default_audio_sample_t srate)
  48 {
  49         int i;
  50         for(i=0; i<128; i++)
  51         {
  52                 note_frqs[i] = (2.0 * 440.0 / 32.0) * pow(2, (((jack_default_audio_sample_t)i - 9.0) / 12.0)) / srate;
  53         }
  54 }
  55
  56 static int process(jack_nframes_t nframes, void *arg)
  57 {
  58         int i;
  59         void* port_buf = jack_port_get_buffer(input_port, nframes);
  60         jack_default_audio_sample_t *out = (jack_default_audio_sample_t *) jack_port_get_buffer (output_port, nframes);
  61         jack_midi_event_t in_event;
  62         jack_nframes_t event_index = 0;
  63         jack_nframes_t event_count = jack_midi_get_event_count(port_buf);
  64         if(event_count > 1)
  65         {
  66                 printf(" midisine: have %d events\n", event_count);
  67                 for(i=0; i<event_count; i++)
  68                 {
  69                         jack_midi_event_get(&in_event, port_buf, i);
  70                         printf("    event %d time is %d. 1st byte is 0x%x\n", i, in_event.time, *(in_event.buffer));
  71                 }
  72 /*              printf("1st byte of 1st event addr is %p\n", in_events[0].buffer);*/
  73         }
  74         jack_midi_event_get(&in_event, port_buf, 0);
  75         for(i = 0; i < nframes; i++)
  76         {
  77                 if ((in_event.time == i) && (event_index < event_count))
  78                 {
  79                         if (((*(in_event.buffer) & 0xf0)) == 0x90)
  80                         {
  81                 /* note on */
  82                 note = *(in_event.buffer + 1);
  83                 if (*(in_event.buffer + 2) == 0) {
  84                     note_on = 0.0;
  85                 } else {
  86                     note_on = (float)(*(in_event.buffer + 2)) / 127.f;
  87                 }
  88                         }
  89                         else if (((*(in_event.buffer)) & 0xf0) == 0x80)
  90                         {
  91                                 /* note off */
  92                                 note = *(in_event.buffer + 1);
  93                                 note_on = 0.0;
  94                         }
  95                         event_index++;
  96                         if(event_index < event_count)
  97                                 jack_midi_event_get(&in_event, port_buf, event_index);
  98                 }
  99                 ramp += note_frqs[note];
 100                 ramp = (ramp > 1.0) ? ramp - 2.0 : ramp;
 101                 out[i] = note_on*sin(2*M_PI*ramp);
 102         }
 103         return 0;
 104 }
 105
 106 static int srate(jack_nframes_t nframes, void *arg)
 107 {
 108         printf("the sample rate is now %" PRIu32 "/sec\n", nframes);
 109         calc_note_frqs((jack_default_audio_sample_t)nframes);
 110         return 0;
 111 }
 112
 113 static void jack_shutdown(void *arg)
 114 {
 115     fprintf(stderr, "JACK shut down, exiting ...\n");
 116         exit(1);
 117 }
 118
 119 int main(int narg, char **args)
 120 {
 121         if ((client = jack_client_open("midisine", JackNullOption, NULL)) == 0)
 122         {
 123                 fprintf(stderr, "JACK server not running?\n");
 124                 return 1;
 125         }
 126
 127         calc_note_frqs(jack_get_sample_rate (client));
 128
 129         jack_set_process_callback (client, process, 0);
 130
 131         jack_set_sample_rate_callback (client, srate, 0);
 132
 133         jack_on_shutdown (client, jack_shutdown, 0);
 134
 135         input_port = jack_port_register (client, "midi_in", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
 136         output_port = jack_port_register (client, "audio_out", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
 137
 138         if (jack_activate (client))
 139         {
 140                 fprintf(stderr, "cannot activate client");
 141                 return 1;
 142         }
 143
 144         /* install a signal handler to properly quits jack client */
 145 #ifndef WIN32
 146         signal(SIGQUIT, signal_handler);
 147         signal(SIGHUP, signal_handler);
 148 #endif
 149         signal(SIGTERM, signal_handler);
 150         signal(SIGINT, signal_handler);
 151
 152         /* run until interrupted */
 153         while(1) {
 154 #ifdef WIN32
 155                 Sleep(1*1000);
 156 #else
 157                 sleep(1);
 158 #endif
 159         }
 160         jack_client_close(client);
 161         exit (0);
 162 }
 163