example-clients/midi_dump.c

   1 #include <stdio.h>
   2 #include <unistd.h>
   3 #include <assert.h>
   4 #include <jack/jack.h>
   5 #include <jack/midiport.h>
   6
   7 static jack_port_t* port;
   8
   9 static void
  10 describe (jack_midi_event_t* event, char* buffer, size_t buflen)
  11 {
  12         assert (buflen > 0);
  13
  14         buffer[0] = '\0';
  15
  16         if (event->size == 0) {
  17                 return;
  18         }
  19
  20         int type = event->buffer[0] & 0xf0;
  21         int channel = event->buffer[0] & 0xf;
  22
  23         switch (type) {
  24         case 0x90:
  25                 assert (event->size == 3);
  26                 snprintf (buffer, buflen, "note on (channel %d): pitch %d, velocity %d", channel, event->buffer[1], event->buffer[2]);
  27                 break;
  28         case 0x80:
  29                 assert (event->size == 3);
  30                 snprintf (buffer, buflen, "note off (channel %d): pitch %d, velocity %d", channel, event->buffer[1], event->buffer[2]);
  31                 break;
  32         case 0xb0:
  33                 assert (event->size == 3);
  34                 snprintf (buffer, buflen, "control change (channel %d): controller %d, value %d", channel, event->buffer[1], event->buffer[2]);
  35                 break;
  36         default:
  37                 break;
  38         }
  39 }
  40
  41 int
  42 process (jack_nframes_t frames, void* arg)
  43 {
  44         void* buffer;
  45         jack_nframes_t N;
  46         jack_nframes_t i;
  47         char description[256];
  48
  49         buffer = jack_port_get_buffer (port, frames);
  50         assert (buffer);
  51
  52         N = jack_midi_get_event_count (buffer);
  53         for (i = 0; i < N; ++i) {
  54                 jack_midi_event_t event;
  55                 int r;
  56
  57                 r = jack_midi_event_get (&event, buffer, i);
  58                 if (r == 0) {
  59                         size_t j;
  60
  61                         printf ("%d:", event.time);
  62                         for (j = 0; j < event.size; ++j) {
  63                                 printf (" %x", event.buffer[j]);
  64                         }
  65
  66                         describe (&event, description, sizeof (description));
  67                         printf (" %s", description);
  68
  69                         printf ("\n");
  70                 }
  71         }
  72
  73         return 0;
  74 }
  75
  76
  77 int
  78 main (int argc, char* argv[])
  79 {
  80         jack_client_t* client;
  81         char const default_name[] = "midi-monitor";
  82         char const * client_name;
  83         int r;
  84
  85         if (argc == 2) {
  86                 client_name = argv[1];
  87         } else {
  88                 client_name = default_name;
  89         }
  90
  91         client = jack_client_open (client_name, JackNullOption, NULL);
  92         if (client == NULL) {
  93                 fprintf (stderr, "Could not create JACK client.\n");
  94                 exit (EXIT_FAILURE);
  95         }
  96
  97         jack_set_process_callback (client, process, 0);
  98
  99         port = jack_port_register (client, "input", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
 100         if (port == NULL) {
 101                 fprintf (stderr, "Could not register port.\n");
 102                 exit (EXIT_FAILURE);
 103         }
 104
 105         r = jack_activate (client);
 106         if (r != 0) {
 107                 fprintf (stderr, "Could not activate client.\n");
 108                 exit (EXIT_FAILURE);
 109         }
 110
 111         /* run until interrupted */
 112         while (1) {
 113         #ifdef WIN32
 114                 Sleep(1000);
 115         #else
 116                 sleep(1);
 117         #endif
 118         };
 119
 120         return 0;
 121 }