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         for (j = 0; j < num_notes; j++) {
  61             if (note_starts[j] == loop_index) {
  62                 if ((buffer = jack_midi_event_reserve(port_buf, i, 3))) {
  63                     /* printf("wrote a note on, port buffer = 0x%x, event buffer = 0x%x\n", port_buf, buffer); */
  64                     buffer[2] = 64;             /* velocity */
  65                     buffer[1] = note_frqs[j];
  66                     buffer[0] = 0x90;   /* note on */
  67                 }
  68             } else if (note_starts[j] + note_lengths[j] == loop_index) {
  69                 if ((buffer = jack_midi_event_reserve(port_buf, i, 3))) {
  70                     /* printf("wrote a note off, port buffer = 0x%x, event buffer = 0x%x\n", port_buf, buffer); */
  71                     buffer[2] = 64;             /* velocity */
  72                     buffer[1] = note_frqs[j];
  73                     buffer[0] = 0x80;   /* note off */
  74                 }
  75             }
  76         }
  77         loop_index = loop_index+1 >= loop_nsamp ? 0 : loop_index+1;
  78     }
  79     return 0;
  80 }
  81
  82 int main(int narg, char **args)
  83 {
  84         int i;
  85         jack_nframes_t nframes;
  86         if ((narg<6) || ((narg-3)%3 != 0)) {
  87                 usage();
  88                 exit(1);
  89         }
  90         if ((client = jack_client_open (args[1], JackNullOption, NULL)) == 0) {
  91                 fprintf (stderr, "JACK server not running?\n");
  92                 return 1;
  93         }
  94         jack_set_process_callback (client, process, 0);
  95         output_port = jack_port_register (client, "out", JACK_DEFAULT_MIDI_TYPE, JackPortIsOutput, 0);
  96         nframes = jack_get_buffer_size(client);
  97         loop_index = 0;
  98         num_notes = (narg - 3)/3;
  99         note_frqs = malloc(num_notes*sizeof(unsigned char));
 100         note_starts = malloc(num_notes*sizeof(jack_nframes_t));
 101         note_lengths = malloc(num_notes*sizeof(jack_nframes_t));
 102         loop_nsamp = atoi(args[2]);
 103         for (i = 0; i < num_notes; i++) {
 104                 note_starts[i] = atoi(args[3 + 3*i]);
 105                 note_frqs[i] = atoi(args[4 + 3*i]);
 106                 note_lengths[i] = atoi(args[5 + 3*i]);
 107         }
 108
 109         if (jack_activate(client)) {
 110                 fprintf (stderr, "cannot activate client");
 111                 return 1;
 112         }
 113
 114         /* install a signal handler to properly quits jack client */
 115 #ifndef WIN32
 116         signal(SIGQUIT, signal_handler);
 117         signal(SIGHUP, signal_handler);
 118 #endif
 119         signal(SIGTERM, signal_handler);
 120         signal(SIGINT, signal_handler);
 121
 122         /* run until interrupted */
 123         while (1) {
 124 #ifdef WIN32
 125                 Sleep(1*1000);
 126 #else
 127                 sleep(1);
 128 #endif
 129         };
 130
 131     jack_client_close(client);
 132         exit (0);
 133 }