example-clients/external_metro.cpp

   1 /*
   2  Copyright (C) 2002 Anthony Van Groningen
   3
   4  This program is free software; you can redistribute it and/or modify
   5  it under the terms of the GNU General Public License as published by
   6  the Free Software Foundation; either version 2 of the License, or
   7  (at your option) any later version.
   8
   9  This program is distributed in the hope that it will be useful,
  10  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  GNU General Public License for more details.
  13
  14  You should have received a copy of the GNU General Public License
  15  along with this program; if not, write to the Free Software
  16  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17 */
  18
  19 #include "external_metro.h"
  20
  21 typedef jack_default_audio_sample_t sample_t;
  22
  23 const double PI = 3.14;
  24
  25 static int process_audio (jack_nframes_t nframes, void* arg)
  26 {
  27     ExternalMetro* metro = (ExternalMetro*)arg;
  28     sample_t *buffer = (sample_t *) jack_port_get_buffer (metro->output_port, nframes);
  29     jack_nframes_t frames_left = nframes;
  30
  31     while (metro->wave_length - metro->offset < frames_left) {
  32         memcpy (buffer + (nframes - frames_left), metro->wave + metro->offset, sizeof (sample_t) * (metro->wave_length - metro->offset));
  33         frames_left -= metro->wave_length - metro->offset;
  34         metro->offset = 0;
  35     }
  36     if (frames_left > 0) {
  37         memcpy (buffer + (nframes - frames_left), metro->wave + metro->offset, sizeof (sample_t) * frames_left);
  38         metro->offset += frames_left;
  39     }
  40
  41     return 0;
  42 }
  43
  44 ExternalMetro::ExternalMetro(int freq, double max_amp, int dur_arg, int bpm, char* client_name)
  45 {
  46     sample_t scale;
  47     int i, attack_length, decay_length;
  48     double *amp;
  49     int attack_percent = 1, decay_percent = 10;
  50     char *bpm_string = "bpm";
  51
  52     offset = 0;
  53
  54     /* Initial Jack setup, get sample rate */
  55     if (!client_name) {
  56         client_name = (char *) malloc (9 * sizeof (char));
  57         strcpy (client_name, "metro");
  58     }
  59     if ((client = jack_client_new (client_name)) == 0) {
  60         fprintf (stderr, "jack server not running?\n");
  61         return ;
  62     }
  63
  64     jack_set_process_callback (client, process_audio, this);
  65     output_port = jack_port_register (client, bpm_string, JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
  66     input_port = jack_port_register (client, "metro_in", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
  67
  68     sr = jack_get_sample_rate (client);
  69
  70     /* setup wave table parameters */
  71     wave_length = 60 * sr / bpm;
  72     tone_length = sr * dur_arg / 1000;
  73     attack_length = tone_length * attack_percent / 100;
  74     decay_length = tone_length * decay_percent / 100;
  75     scale = 2 * PI * freq / sr;
  76
  77     if (tone_length >= wave_length) {
  78         /*
  79         fprintf (stderr, "invalid duration (tone length = %" PRIu32
  80                  ", wave length = %" PRIu32 "\n", tone_length,
  81                  wave_length);
  82         */
  83         return ;
  84     }
  85     if (attack_length + decay_length > (int)tone_length) {
  86         fprintf (stderr, "invalid attack/decay\n");
  87         return ;
  88     }
  89
  90     /* Build the wave table */
  91     wave = (sample_t *) malloc (wave_length * sizeof(sample_t));
  92     amp = (double *) malloc (tone_length * sizeof(double));
  93
  94     for (i = 0; i < attack_length; i++) {
  95         amp[i] = max_amp * i / ((double) attack_length);
  96     }
  97     for (i = attack_length; i < (int) tone_length - decay_length; i++) {
  98         amp[i] = max_amp;
  99     }
 100     for (i = (int)tone_length - decay_length; i < (int)tone_length; i++) {
 101         amp[i] = - max_amp * (i - (double) tone_length) / ((double) decay_length);
 102     }
 103     for (i = 0; i < (int) tone_length; i++) {
 104         wave[i] = amp[i] * sin (scale * i);
 105     }
 106     for (i = tone_length; i < (int) wave_length; i++) {
 107         wave[i] = 0;
 108     }
 109
 110     if (jack_activate (client)) {
 111         fprintf (stderr, "cannot activate client");
 112     }
 113 }
 114
 115 ExternalMetro::~ExternalMetro()
 116 {
 117     jack_deactivate(client);
 118     jack_port_unregister(client, input_port);
 119     jack_port_unregister(client, output_port);
 120     jack_client_close(client);
 121 }
 122
 123 int main (int argc, char *argv[])
 124 {
 125     ExternalMetro* client1 = NULL;
 126     ExternalMetro* client2 = NULL;
 127     ExternalMetro* client3 = NULL;
 128     ExternalMetro* client4 = NULL;
 129     ExternalMetro* client5 = NULL;
 130
 131     client1 = new ExternalMetro(1200, 0.4, 20, 80, "t1");
 132     client2 = new ExternalMetro(600, 0.4, 20, 150, "t2");
 133     client3 = new ExternalMetro(1000, 0.4, 20, 110, "t3");
 134         client4 = new ExternalMetro(400, 0.4, 20, 200, "t4");
 135     client5 = new ExternalMetro(1500, 0.4, 20, 150, "t5");
 136
 137     while ((getchar() != 'q')) {
 138         sleep(1);
 139     };
 140
 141     delete client1;
 142     delete client2;
 143     delete client3;
 144     delete client4;
 145     delete client5;
 146 }