example-clients/midi_dump.c

   1 // gcc -o jack_midi_dump -Wall midi_dump.c -ljack -pthread
   2
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <assert.h>
   7 #include <inttypes.h>
   8 #include <jack/jack.h>
   9 #include <jack/midiport.h>
  10 #include <jack/ringbuffer.h>
  11
  12 #ifdef __MINGW32__
  13 #include <pthread.h>
  14 #endif
  15
  16 #ifndef WIN32
  17 #include <signal.h>
  18 #include <pthread.h>
  19 #include <sys/mman.h>
  20 #endif
  21
  22 static jack_port_t* port;
  23 static jack_ringbuffer_t *rb = NULL;
  24 static pthread_mutex_t msg_thread_lock = PTHREAD_MUTEX_INITIALIZER;
  25 static pthread_cond_t data_ready = PTHREAD_COND_INITIALIZER;
  26
  27 static int keeprunning = 1;
  28 static uint64_t monotonic_cnt = 0;
  29
  30 #define RBSIZE 100
  31 #define MSG_BUFFER_SIZE 4096
  32
  33 typedef struct {
  34         uint8_t  buffer[MSG_BUFFER_SIZE];
  35         uint32_t size;
  36         uint32_t tme_rel;
  37         uint64_t tme_mon;
  38 } midimsg;
  39
  40 static void
  41 describe (midimsg* event)
  42 {
  43         if (event->size == 0) {
  44                 return;
  45         }
  46
  47         uint8_t type = event->buffer[0] & 0xf0;
  48         uint8_t channel = event->buffer[0] & 0xf;
  49
  50         switch (type) {
  51                 case 0x90:
  52                         assert (event->size == 3);
  53                         printf (" note on  (channel %2d): pitch %3d, velocity %3d", channel, event->buffer[1], event->buffer[2]);
  54                         break;
  55                 case 0x80:
  56                         assert (event->size == 3);
  57                         printf (" note off (channel %2d): pitch %3d, velocity %3d", channel, event->buffer[1], event->buffer[2]);
  58                         break;
  59                 case 0xb0:
  60                         assert (event->size == 3);
  61                         printf (" control change (channel %2d): controller %3d, value %3d", channel, event->buffer[1], event->buffer[2]);
  62                         break;
  63                 default:
  64                         break;
  65         }
  66 }
  67
  68 int
  69 process (jack_nframes_t frames, void* arg)
  70 {
  71         void* buffer;
  72         jack_nframes_t N;
  73         jack_nframes_t i;
  74
  75         buffer = jack_port_get_buffer (port, frames);
  76         assert (buffer);
  77
  78         N = jack_midi_get_event_count (buffer);
  79         for (i = 0; i < N; ++i) {
  80                 jack_midi_event_t event;
  81                 int r;
  82                 r = jack_midi_event_get (&event, buffer, i);
  83
  84                 if (r != 0) {continue;}
  85
  86                 if (event.size > MSG_BUFFER_SIZE) {
  87                         fprintf(stderr, "Error: MIDI message was too large, skipping event. Max. allowed size: %d bytes\n", MSG_BUFFER_SIZE);
  88                 }
  89                 else if (jack_ringbuffer_write_space (rb) >= sizeof(midimsg)) {
  90                         midimsg m;
  91                         m.tme_mon = monotonic_cnt;
  92                         m.tme_rel = event.time;
  93                         m.size    = event.size;
  94                         memcpy (m.buffer, event.buffer, event.size);
  95                         jack_ringbuffer_write (rb, (void *) &m, sizeof(midimsg));
  96                 }
  97                 else {
  98                         fprintf (stderr, "Error: ringbuffer was full, skipping event.\n");
  99                 }
 100         }
 101
 102         monotonic_cnt += frames;
 103
 104         if (pthread_mutex_trylock (&msg_thread_lock) == 0) {
 105                 pthread_cond_signal (&data_ready);
 106                 pthread_mutex_unlock (&msg_thread_lock);
 107         }
 108
 109         return 0;
 110 }
 111
 112 static void wearedone(int sig) {
 113         fprintf(stderr, "Shutting down\n");
 114         keeprunning = 0;
 115 }
 116
 117 static void usage (int status) {
 118         printf ("jack_midi_dump - JACK MIDI Monitor.\n\n");
 119         printf ("Usage: jack_midi_dump [ OPTIONS ] [CLIENT-NAME]\n\n");
 120         printf ("Options:\n\
 121   -a        use absolute timestamps relative to application start\n\
 122   -h        display this help and exit\n\
 123   -r        use relative timestamps to previous MIDI event\n\
 124 \n");
 125         printf ("\n\
 126 This tool listens for MIDI events on a JACK MIDI port and prints\n\
 127 the message to stdout.\n\
 128 \n\
 129 If no client name is given it defaults to 'midi-monitor'.\n\
 130 \n\
 131 See also: jackd(1)\n\
 132 \n");
 133         exit (status);
 134 }
 135
 136 int
 137 main (int argc, char* argv[])
 138 {
 139         jack_client_t* client;
 140         char const default_name[] = "midi-monitor";
 141         char const * client_name;
 142         int time_format = 0;
 143         int r;
 144
 145         int cn = 1;
 146
 147         if (argc > 1) {
 148                 if      (!strcmp (argv[1], "-a")) { time_format = 1; cn = 2; }
 149                 else if (!strcmp (argv[1], "-r")) { time_format = 2; cn = 2; }
 150                 else if (!strcmp (argv[1], "-h")) { usage (EXIT_SUCCESS); }
 151                 else if (argv[1][0] == '-')       { usage (EXIT_FAILURE); }
 152         }
 153
 154         if (argc > cn) {
 155                 client_name = argv[cn];
 156         } else {
 157                 client_name = default_name;
 158         }
 159
 160         client = jack_client_open (client_name, JackNullOption, NULL);
 161         if (client == NULL) {
 162                 fprintf (stderr, "Could not create JACK client.\n");
 163                 exit (EXIT_FAILURE);
 164         }
 165
 166         rb = jack_ringbuffer_create (RBSIZE * sizeof(midimsg));
 167
 168         jack_set_process_callback (client, process, 0);
 169
 170         port = jack_port_register (client, "input", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
 171         if (port == NULL) {
 172                 fprintf (stderr, "Could not register port.\n");
 173                 exit (EXIT_FAILURE);
 174         }
 175
 176 #ifndef WIN32
 177         if (mlockall (MCL_CURRENT | MCL_FUTURE)) {
 178                 fprintf (stderr, "Warning: Can not lock memory.\n");
 179         }
 180 #endif
 181
 182         r = jack_activate (client);
 183         if (r != 0) {
 184                 fprintf (stderr, "Could not activate client.\n");
 185                 exit (EXIT_FAILURE);
 186         }
 187
 188 #ifndef WIN32
 189         signal(SIGHUP, wearedone);
 190         signal(SIGINT, wearedone);
 191 #endif
 192
 193         pthread_mutex_lock (&msg_thread_lock);
 194
 195         uint64_t prev_event = 0;
 196         while (keeprunning) {
 197                 const int mqlen = jack_ringbuffer_read_space (rb) / sizeof(midimsg);
 198                 int i;
 199                 for (i=0; i < mqlen; ++i) {
 200                         size_t j;
 201                         midimsg m;
 202                         jack_ringbuffer_read(rb, (char*) &m, sizeof(midimsg));
 203
 204                         switch(time_format) {
 205                                 case 1:
 206                                         printf ("%7"PRId64":", m.tme_rel + m.tme_mon);
 207                                         break;
 208                                 case 2:
 209                                         printf ("%+6"PRId64":", m.tme_rel + m.tme_mon - prev_event);
 210                                         break;
 211                                 default:
 212                                         printf ("%4d:", m.tme_rel);
 213                                         break;
 214                         }
 215                         for (j = 0; j < m.size && j < sizeof(m.buffer); ++j) {
 216                                 printf (" %02x", m.buffer[j]);
 217                         }
 218
 219                         describe (&m);
 220                         printf("\n");
 221                         prev_event = m.tme_rel + m.tme_mon;
 222                 }
 223                 fflush (stdout);
 224                 pthread_cond_wait (&data_ready, &msg_thread_lock);
 225         }
 226         pthread_mutex_unlock (&msg_thread_lock);
 227
 228         jack_deactivate (client);
 229         jack_client_close (client);
 230         jack_ringbuffer_free (rb);
 231
 232         return 0;
 233 }