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 <math.h>
  25
  26 #include <jack/jack.h>
  27 #include <jack/midiport.h>
  28
  29 jack_port_t *input_port;
  30 jack_port_t *output_port;
  31 jack_default_audio_sample_t ramp=0.0;
  32 jack_default_audio_sample_t note_on;
  33 unsigned char note = 0;
  34 jack_default_audio_sample_t note_frqs[128];
  35
  36 void calc_note_frqs(jack_default_audio_sample_t srate)
  37 {
  38         int i;
  39         for(i=0; i<128; i++)
  40         {
  41                 note_frqs[i] = (2.0 * 440.0 / 32.0) * pow(2, (((jack_default_audio_sample_t)i - 9.0) / 12.0)) / srate;
  42         }
  43 }
  44
  45 int process(jack_nframes_t nframes, void *arg)
  46 {
  47         int i;
  48         void* port_buf = jack_port_get_buffer(input_port, nframes);
  49         jack_default_audio_sample_t *out = (jack_default_audio_sample_t *) jack_port_get_buffer (output_port, nframes);
  50         jack_midi_event_t in_event;
  51         jack_nframes_t event_index = 0;
  52         jack_nframes_t event_count = jack_midi_get_event_count(port_buf);
  53         if(event_count > 1)
  54         {
  55                 printf(" midisine: have %d events\n", event_count);
  56                 for(i=0; i<event_count; i++)
  57                 {
  58                         jack_midi_event_get(&in_event, port_buf, i);
  59                         printf("    event %d time is %d. 1st byte is 0x%x\n", i, in_event.time, *(in_event.buffer));
  60                 }
  61 /*              printf("1st byte of 1st event addr is %p\n", in_events[0].buffer);*/
  62         }
  63         jack_midi_event_get(&in_event, port_buf, 0);
  64         for(i=0; i<nframes; i++)
  65         {
  66                 if((in_event.time == i) && (event_index < event_count))
  67                 {
  68                         if( ((*(in_event.buffer) & 0xf0)) == 0x90 )
  69                         {
  70                                 /* note on */
  71                                 note = *(in_event.buffer + 1);
  72                                 note_on = 1.0;
  73                         }
  74                         else if( ((*(in_event.buffer)) & 0xf0) == 0x80 )
  75                         {
  76                                 /* note off */
  77                                 note = *(in_event.buffer + 1);
  78                                 note_on = 0.0;
  79                         }
  80                         event_index++;
  81                         if(event_index < event_count)
  82                                 jack_midi_event_get(&in_event, port_buf, event_index);
  83                 }
  84                 ramp += note_frqs[note];
  85                 ramp = (ramp > 1.0) ? ramp - 2.0 : ramp;
  86                 out[i] = note_on*sin(2*M_PI*ramp);
  87         }
  88         return 0;
  89 }
  90
  91 int srate(jack_nframes_t nframes, void *arg)
  92 {
  93         printf("the sample rate is now %" PRIu32 "/sec\n", nframes);
  94         calc_note_frqs((jack_default_audio_sample_t)nframes);
  95         return 0;
  96 }
  97
  98 void jack_shutdown(void *arg)
  99 {
 100         exit(1);
 101 }
 102
 103 int main(int narg, char **args)
 104 {
 105         jack_client_t *client;
 106
 107         if ((client = jack_client_new("midisine")) == 0)
 108         {
 109                 fprintf(stderr, "jack server not running?\n");
 110                 return 1;
 111         }
 112
 113         calc_note_frqs(jack_get_sample_rate (client));
 114
 115         jack_set_process_callback (client, process, 0);
 116
 117         jack_set_sample_rate_callback (client, srate, 0);
 118
 119         jack_on_shutdown (client, jack_shutdown, 0);
 120
 121         input_port = jack_port_register (client, "midi_in", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
 122         output_port = jack_port_register (client, "audio_out", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
 123
 124         if (jack_activate (client))
 125         {
 126                 fprintf(stderr, "cannot activate client");
 127                 return 1;
 128         }
 129
 130         /* run until interrupted */
 131         while(1)
 132         {
 133                 sleep(1);
 134         }
 135         jack_client_close(client);
 136         exit (0);
 137 }
 138