jack_mix_box.c

   1 /*****************************************************************************
   2  *
   3  *   This file is part of jack_mixer
   4  *
   5  *   Copyright (C) 2006 Nedko Arnaudov <nedko@arnaudov.name>
   6  *   Copyright (C) 2009-2011 Frederic Peters <fpeters@0d.be>
   7  *
   8  *   This program is free software; you can redistribute it and/or modify
   9  *   it under the terms of the GNU General Public License as published by
  10  *   the Free Software Foundation; version 2 of the License
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  *****************************************************************************/
  22
  23 /*
  24  * jack_mix_box is a most minimalistic jack mixer, a set of mono/sterero input
  25  * channels, mixed to a single output channel, with the volume of the
  26  * input channels controlled by MIDI control change (CC) codes.
  27  *
  28  */
  29
  30 #include <stdlib.h>
  31 #include <stdio.h>
  32 #include <string.h>
  33 #include <stdbool.h>
  34 #include <getopt.h>
  35 #include <signal.h>
  36 #include <unistd.h>
  37 #include "jack_mixer.h"
  38
  39 jack_mixer_t mixer;
  40 bool keepRunning = true;
  41
  42 void
  43 usage()
  44 {
  45         printf("Usage: ");
  46         printf("jack_mix_box [-n <name>] [-p] [-s] [-v <dB>] MIDI_CC...\n");
  47         printf("\n");
  48         printf("-h|--help\tprint this help message\n");
  49         printf("-n|--name\tset JACK client name\n");
  50         printf("-p|--pickup\tenable MIDI pickup mode (default: jump-to-value)\n");
  51         printf("-s|--stereo\tmake all input channels stereo with left+right input\n");
  52         printf("-v|--volume\tinitial volume gain in dB, default is 0.0 (i.e. unity gain)\n");
  53         printf("\n");
  54         printf("Each positional argument is interpreted as a MIDI Control Change number and adds\n");
  55         printf("a mixer channel with one (mono) or left+right (stereo) inputs, whose volume can\n");
  56         printf("be controlled via the given MIDI Control Change.\n");
  57         printf("\n");
  58         printf("Send SIGUSR1 to the process to have the current volumes reported per input channel.\n\n");
  59 }
  60
  61 void
  62 reportVolume(int sig)
  63 {
  64         (void)sig;
  65         channels_volumes_read(mixer);
  66 }
  67
  68 void
  69 triggerShutDown(int sig)
  70 {
  71         (void)sig;
  72         keepRunning = false;
  73 }
  74
  75 int
  76 main(int argc, char *argv[])
  77 {
  78         jack_mixer_scale_t scale;
  79         jack_mixer_channel_t main_mix_channel;
  80         char *jack_cli_name = NULL;
  81         int channel_index;
  82         bool bStereo = false;
  83         enum midi_behavior_mode ePickup = Jump_To_Value;
  84         double initialVolume = 0.0f; //in dbFS
  85
  86         while (1) {
  87                 int c;
  88                 static struct option long_options[] =
  89                 {
  90                         {"name",  required_argument, 0, 'n'},
  91                         {"help",  no_argument, 0, 'h'},
  92                         {"pickup",  no_argument, 0, 'p'},
  93                         {"stereo",  no_argument, 0, 's'},
  94                         {"volume",  required_argument, 0, 'v'},
  95                         {0, 0, 0, 0}
  96                 };
  97                 int option_index = 0;
  98
  99                 c = getopt_long (argc, argv, "sphn:v:", long_options, &option_index);
 100                 if (c == -1)
 101                         break;
 102
 103                 switch (c) {
 104                         case 'n':
 105                                 jack_cli_name = strdup(optarg);
 106                                 break;
 107                         case 's':
 108                                 bStereo = true;
 109                                 break;
 110                         case 'v':
 111                                 initialVolume = strtod(optarg, NULL);
 112                                 break;
 113                         case 'h':
 114                                 usage();
 115                                 exit(0);
 116                                 break;
 117                         case 'p':
 118                                 ePickup = Pick_Up;
 119                                 break;
 120                         default:
 121                                 fprintf(stderr, "Unknown argument, aborting.\n");
 122                                 exit(1);
 123                 }
 124         }
 125
 126         if (optind == argc) {
 127                 fprintf(stderr, "You must specify at least one input channel\n");
 128                 exit(1);
 129         }
 130
 131         scale = scale_create();
 132         scale_add_threshold(scale, -70.0, 0.0);
 133         scale_add_threshold(scale, 0.0, 1.0);
 134         scale_calculate_coefficients(scale);
 135
 136         if (jack_cli_name == NULL) {
 137                 jack_cli_name = strdup("jack_mix_box");
 138         }
 139
 140         mixer = create(jack_cli_name, false);
 141         main_mix_channel = add_output_channel(mixer, "MAIN", true, false);
 142         channel_set_midi_scale(main_mix_channel, scale);
 143         channel_volume_write(main_mix_channel, 0.0);
 144         set_midi_behavior_mode(mixer, ePickup);
 145
 146         channel_index = 0;
 147         while (optind < argc) {
 148                 char *channel_name;
 149                 jack_mixer_channel_t channel;
 150
 151                 channel_index += 1;
 152                 channel_name = malloc(15);
 153                 if (snprintf(channel_name, 15, "Channel %d", channel_index) >= 15) {
 154                         free(channel_name);
 155                         abort();
 156                 }
 157                 channel = add_channel(mixer, channel_name, bStereo);
 158                 if (channel == NULL) {
 159                         fprintf(stderr, "Failed to add channel %d, aborting\n", channel_index);
 160                         exit(1);
 161                 }
 162                 channel_set_volume_midi_cc(channel, atoi(argv[optind++]));
 163                 channel_set_midi_scale(channel, scale);
 164                 channel_volume_write(channel, initialVolume);
 165                 free(channel_name);
 166         }
 167
 168         signal(SIGUSR1, reportVolume);
 169         signal(SIGTERM, triggerShutDown);
 170         signal(SIGHUP, triggerShutDown);
 171         signal(SIGINT, triggerShutDown);
 172
 173         while (keepRunning) {
 174                 usleep(500u * 1000u); //500msec
 175         }
 176
 177         remove_channels(mixer);
 178         remove_output_channel(main_mix_channel);
 179         destroy(mixer);
 180         scale_destroy(scale);
 181         free(jack_cli_name);
 182         return 0;
 183 }