plugins/libresample.c

   1 /* gAlan - Graphical Audio Language
   2  * Copyright (C) 1999 Tony Garnock-Jones
   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <stdio.h>
  22 #include <stddef.h>
  23
  24 #include <gdk/gdk.h>
  25 #include <gtk/gtk.h>
  26 #include <gmodule.h>
  27
  28 #include "global.h"
  29 #include "generator.h"
  30 #include "comp.h"
  31 #include "control.h"
  32 #include "gencomp.h"
  33
  34 #define GENERATOR_CLASS_NAME    "resample"
  35 #define GENERATOR_CLASS_PATH    "Timebase/Resample"
  36
  37 #define SIG_INPUT               0
  38 #define SIG_OUTPUT              0
  39
  40 #define EVT_FACTOR              0
  41 #define EVT_NOTE                1
  42
  43 typedef struct Data {
  44   gdouble factor;
  45 } Data;
  46
  47 #define FREQ_C0 16.351598
  48 #define FREQ_A4 440
  49 #define NOTE_C4 48
  50 #define NOTE_A4 57
  51 #define NOTE_TO_FACTOR(n, centre)               (pow(2, ((n) - (centre)) / 12.0))
  52
  53 PRIVATE int init_instance(Generator *g) {
  54   Data *data = safe_malloc(sizeof(Data));
  55   g->data = data;
  56
  57   data->factor = 1;
  58
  59   return 1;
  60 }
  61
  62 PRIVATE void destroy_instance(Generator *g) {
  63   free(g->data);
  64 }
  65
  66 PRIVATE void unpickle_instance(Generator *g, ObjectStoreItem *item, ObjectStore *db) {
  67   Data *data = safe_malloc(sizeof(Data));
  68   g->data = data;
  69
  70   data->factor = objectstore_item_get_double(item, "resample_factor", 1);
  71 }
  72
  73 PRIVATE void pickle_instance(Generator *g, ObjectStoreItem *item, ObjectStore *db) {
  74   Data *data = g->data;
  75   objectstore_item_set_double(item, "resample_factor", data->factor);
  76 }
  77
  78 PRIVATE SAMPLETIME output_range(Generator *g, OutputSignalDescriptor *sig) {
  79   Data *data = g->data;
  80
  81   if (data->factor == 0)
  82     return 0;   /* GIGO */
  83
  84   return gen_get_randomaccess_input_range(g, SIG_INPUT, 0) / data->factor;
  85 }
  86
  87 PRIVATE gboolean output_generator(Generator *g, OutputSignalDescriptor *sig,
  88                                   SAMPLETIME offset, SAMPLE *buf, int buflen) {
  89   Data *data = g->data;
  90   SAMPLE tmpbuf[MAXIMUM_REALTIME_STEP*5];
  91   int i;
  92   gdouble o;
  93
  94   if (!gen_read_randomaccess_input(g, SIG_INPUT, 0,
  95                                    offset*data->factor, tmpbuf, buflen*data->factor + 1))
  96     return FALSE;
  97
  98   for (i = 0, o = 0; i < buflen; i++, o += data->factor) {
  99     int oi = floor(o);
 100     gdouble fract = o - oi;
 101     buf[i] = ( tmpbuf[oi]*(1-fract) + tmpbuf[oi+1]*fract ) / 2;
 102   }
 103
 104   return TRUE;
 105 }
 106
 107 PRIVATE void evt_factor_handler(Generator *g, AEvent *event) {
 108   ((Data *) g->data)->factor = MAX(MIN(event->d.number, 4), 0);
 109 }
 110
 111 PRIVATE void evt_note_handler(Generator *g, AEvent *event) {
 112   ((Data *) g->data)->factor = MAX(MIN(NOTE_TO_FACTOR(event->d.number, NOTE_C4), 4), 0);
 113 }
 114
 115 PRIVATE InputSignalDescriptor input_sigs[] = {
 116   { "Input", SIG_FLAG_RANDOMACCESS },
 117   { NULL, }
 118 };
 119
 120 PRIVATE OutputSignalDescriptor output_sigs[] = {
 121   { "Output", SIG_FLAG_RANDOMACCESS, { NULL, { output_range, output_generator } } },
 122   { NULL, }
 123 };
 124
 125 PRIVATE ControlDescriptor controls[] = {
 126   /* { kind, name, min,max,step,page, size,editable, is_dst,queue_number,
 127        init,destroy,refresh,refresh_data }, */
 128   { CONTROL_KIND_KNOB, "factor", 0.5,4,0.01,0.01, 0,TRUE, TRUE,EVT_FACTOR,
 129     NULL,NULL, control_double_updater, (gpointer) offsetof(Data, factor) },
 130   { CONTROL_KIND_KNOB, "note", 0,127,1,1, 0,TRUE, TRUE,EVT_NOTE,
 131     NULL,NULL, NULL },
 132   { CONTROL_KIND_NONE, }
 133 };
 134
 135 PRIVATE void setup_class(void) {
 136   GeneratorClass *k = gen_new_generatorclass(GENERATOR_CLASS_NAME, FALSE, 2, 0,
 137                                              input_sigs, output_sigs, controls,
 138                                              init_instance, destroy_instance,
 139                                              unpickle_instance, pickle_instance);
 140
 141   gen_configure_event_input(k, EVT_FACTOR, "Factor", evt_factor_handler);
 142   gen_configure_event_input(k, EVT_NOTE, "Note", evt_note_handler);
 143
 144   gencomp_register_generatorclass(k, FALSE, GENERATOR_CLASS_PATH, NULL, NULL);
 145 }
 146
 147 PUBLIC void init_plugin(void) {
 148   setup_class();
 149 }