Linux Cross Reference
JACK/example-clients/showtime.c

** Warning: Cannot open xref database.
   #include <stdio.h>
   #include <errno.h>
   #include <unistd.h>
   #include <signal.h>
   #include <stdlib.h>
   
   #include <jack/jack.h>
   #include <jack/transport.h>
   
  jack_client_t *client;
  
  
  void
  showtime ()
  {
          jack_position_t current;
          jack_transport_state_t transport_state;
  
          transport_state = jack_transport_query (client, &current);
  
          printf ("frame: %7" PRIu32 "\t", current.frame);
  
          switch (transport_state) {
          case JackTransportStopped:
                  printf ("state: Stopped");
                  break;
          case JackTransportRolling:
                  printf ("state: Rolling");
                  break;
          case JackTransportStarting:
                  printf ("state: Starting");
                  break;
          default:
                  printf ("state: [unknown]");
          }
  
          if (current.valid & JackPositionBBT)
                  printf ("\tBBT: %3" PRIi32 "|%" PRIi32 "|%04"
                          PRIi32, current.bar, current.beat, current.tick);
  
          if (current.valid & JackPositionTimecode)
                  printf ("\tTC: (%.6f, %.6f)",
                          current.frame_time, current.next_time);
          printf ("\n");
  }
  
  void
  jack_shutdown (void *arg)
  {
          exit (1);
  }
  
  void
  signal_handler (int sig)
  {
          jack_client_close (client);
          fprintf (stderr, "signal received, exiting ...\n");
          exit (0);
  }
  
  int
  main (int argc, char *argv[])
  
  {
          /* try to become a client of the JACK server */
  
          if ((client = jack_client_new ("showtime")) == 0) {
                  fprintf (stderr, "jack server not running?\n");
                  return 1;
          }
  
          signal (SIGQUIT, signal_handler);
          signal (SIGTERM, signal_handler);
          signal (SIGHUP, signal_handler);
          signal (SIGINT, signal_handler);
  
          /* tell the JACK server to call `jack_shutdown()' if
             it ever shuts down, either entirely, or if it
             just decides to stop calling us.
          */
  
          jack_on_shutdown (client, jack_shutdown, 0);
  
          /* tell the JACK server that we are ready to roll */
  
          if (jack_activate (client)) {
                  fprintf (stderr, "cannot activate client");
                  return 1;
          }
          
          while (1) {
                  usleep (100000);
                  showtime ();
          }
  
          jack_client_close (client);
          exit (0);
  }