example-clients/midiseq.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 <jack/jack.h>
  20 #include <jack/midiport.h>
  21 #include <stdio.h>
  22 #include <signal.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25
  26 jack_client_t *client;
  27 jack_port_t *output_port;
  28
  29 unsigned char* note_frqs;
  30 jack_nframes_t* note_starts;
  31 jack_nframes_t* note_lengths;
  32 jack_nframes_t num_notes;
  33 jack_nframes_t loop_nsamp;
  34 jack_nframes_t loop_index;
  35
  36 static void signal_handler(int sig)
  37 {
  38         jack_client_close(client);
  39         fprintf(stderr, "signal received, exiting ...\n");
  40         exit(0);
  41 }
  42
  43 static void usage()
  44 {
  45         fprintf(stderr, "usage: jack_midiseq name nsamp [startindex note nsamp] ...... [startindex note nsamp]\n");
  46         fprintf(stderr, "eg: jack_midiseq Sequencer 24000 0 60 8000 12000 63 8000\n");
  47         fprintf(stderr, "will play a 1/2 sec loop (if srate is 48khz) with a c4 note at the start of the loop\n");
  48         fprintf(stderr, "that lasts for 12000 samples, then a d4# that starts at 1/4 sec that lasts for 800 samples\n");
  49 }
  50
  51 static int process(jack_nframes_t nframes, void *arg)
  52 {
  53         int i,j;
  54         void* port_buf = jack_port_get_buffer(output_port, nframes);
  55         unsigned char* buffer;
  56         jack_midi_clear_buffer(port_buf);
  57         /*memset(buffer, 0, nframes*sizeof(jack_default_audio_sample_t));*/
  58
  59         for(i=0; i<nframes; i++)
  60         {
  61                 for(j=0; j<num_notes; j++)
  62                 {
  63                         if(note_starts[j] == loop_index)
  64                         {
  65                                 buffer = jack_midi_event_reserve(port_buf, i, 3);
  66 /*                              printf("wrote a note on, port buffer = 0x%x, event buffer = 0x%x\n", port_buf, buffer);*/
  67                                 buffer[2] = 64;         /* velocity */
  68                                 buffer[1] = note_frqs[j];
  69                                 buffer[0] = 0x90;       /* note on */
  70                         }
  71                         else if(note_starts[j] + note_lengths[j] == loop_index)
  72                         {
  73                                 buffer = jack_midi_event_reserve(port_buf, i, 3);
  74 /*                              printf("wrote a note off, port buffer = 0x%x, event buffer = 0x%x\n", port_buf, buffer);*/
  75                                 buffer[2] = 64;         /* velocity */
  76                                 buffer[1] = note_frqs[j];
  77                                 buffer[0] = 0x80;       /* note off */
  78                         }
  79                 }
  80                 loop_index = loop_index+1 >= loop_nsamp ? 0 : loop_index+1;
  81         }
  82         return 0;
  83 }
  84
  85 int main(int narg, char **args)
  86 {
  87         int i;
  88         jack_nframes_t nframes;
  89         if((narg<6) || ((narg-3)%3 !=0))
  90         {
  91                 usage();
  92                 exit(1);
  93         }
  94         if((client = jack_client_open (args[1], JackNullOption, NULL)) == 0)
  95         {
  96                 fprintf (stderr, "JACK server not running?\n");
  97                 return 1;
  98         }
  99         jack_set_process_callback (client, process, 0);
 100         output_port = jack_port_register (client, "out", JACK_DEFAULT_MIDI_TYPE, JackPortIsOutput, 0);
 101         nframes = jack_get_buffer_size(client);
 102         loop_index = 0;
 103         num_notes = (narg - 3)/3;
 104         note_frqs = malloc(num_notes*sizeof(unsigned char));
 105         note_starts = malloc(num_notes*sizeof(jack_nframes_t));
 106         note_lengths = malloc(num_notes*sizeof(jack_nframes_t));
 107         loop_nsamp = atoi(args[2]);
 108         for(i=0; i<num_notes; i++)
 109         {
 110                 note_starts[i] = atoi(args[3 + 3*i]);
 111                 note_frqs[i] = atoi(args[4 + 3*i]);
 112                 note_lengths[i] = atoi(args[5 + 3*i]);
 113         }
 114
 115         if (jack_activate(client))
 116         {
 117                 fprintf (stderr, "cannot activate client");
 118                 return 1;
 119         }
 120
 121     /* install a signal handler to properly quits jack client */
 122     signal(SIGQUIT, signal_handler);
 123         signal(SIGTERM, signal_handler);
 124         signal(SIGHUP, signal_handler);
 125         signal(SIGINT, signal_handler);
 126
 127     /* run until interrupted */
 128         while (1) {
 129                 sleep(1);
 130         };
 131
 132     jack_client_close(client);
 133         exit (0);
 134 }