main.c

   1 /* -*- Mode: C ; c-basic-offset: 3 -*- */
   2 /*
   3  * Control JACK transport using MMC (MIDI)
   4  *
   5  * Copyright (c) 2006,2007,2008 Nedko Arnaudov <nedko@arnaudov.name>
   6  * Copyright (c) 2008 Alex Montgomery <apmontgomery@gmail.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it under
   9  * the terms of the GNU General Public License as published by the Free Software
  10  * Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT ANY
  13  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  14  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
  19  */
  20
  21 #include <signal.h>
  22 #include <unistd.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25
  26 #include "common.h"
  27
  28
  29 /* the signal handler */
  30 void signalled(int signal)
  31 {
  32    g_quit = 1;
  33 }
  34
  35 // foward declares
  36 void process_command_line(int argc, char *argv[], uint32_t* device_frame_rate, uint32_t* jitter_tolerance, int* verbose);
  37 void cleanup();
  38
  39 int main(int argc, char *argv[])
  40 {
  41    int ret = 0;
  42
  43    // frame rate (frames per second) of the MMC controlling device
  44    uint32_t device_frame_rate = 30; // command line equivalent: -f 30
  45
  46    // jitter tolerance in milliseconds
  47    uint32_t jitter_tolerance = 50; //command line: -t 50
  48
  49    int verbose = 0; // pass -v on the command line to turn this on
  50
  51    // read the jitter tolerance, verbose setting, and device frame rate from command line
  52    process_command_line(argc, argv, &device_frame_rate, &jitter_tolerance, &verbose);
  53
  54    printf("%s starting with a jitter tolerance of %d milliseconds and a device frame rate of %d per second.\n\n",
  55           argv[0], jitter_tolerance, device_frame_rate);
  56
  57    // setup our signal handler signalled() above, so we can exit cleanly
  58    signal(SIGINT, signalled);
  59
  60    ret = init_alsa_sequencer("jackctlmmc");
  61    if (ret < 0)
  62    {
  63       cleanup();
  64       exit(0);
  65    }
  66
  67    if (init_jack("jackctlmmc") < 0)
  68    {
  69       printf("couldn't connect to jack server. Either it's not running or the client name is already taken\n");
  70       cleanup();
  71       exit(0);
  72    }
  73
  74    init_lash(argc, argv);
  75    activate_jack();
  76
  77    // start listening for and handling MMC events, stops when g_quit is true (SIGINT)
  78    listen_loop(device_frame_rate, jitter_tolerance, verbose);
  79
  80    // so we shall quit, eh? ok, cleanup time. otherwise jack would probably produce an xrun on shutdown
  81    cleanup();
  82
  83    if (verbose)
  84       printf("exited normally\n");
  85
  86    return 0;
  87 }
  88
  89
  90 void process_command_line(int argc, char *argv[], // IN parameters
  91                           uint32_t* device_frame_rate, uint32_t* jitter_tolerance, int* verbose) // OUT parameters
  92 {
  93    int parameter;
  94    while ((parameter = getopt(argc, argv, "f:t:v")) != -1)
  95    {
  96       switch (parameter)
  97       {
  98          case 'v':
  99             *verbose = 1;
 100             break;
 101          case 'f':
 102             *device_frame_rate = atoi(optarg);
 103             break;
 104          case 't':
 105             *jitter_tolerance = atoi(optarg);
 106             break;
 107          case '?':
 108             fprintf(stderr, "usage: %s -f <device_frames_per_second> -t <jitter_tolerance_in_ms>\n", argv[0]);
 109             exit(1);
 110             break;
 111       }
 112    }
 113 }
 114
 115 void cleanup()
 116 {
 117    printf("cleaning up\n");
 118    cleanup_globals();
 119 }