swfdec/swfdec_sound_matrix.c

   1 /* Swfdec
   2  * Copyright (C) 2008 Benjamin Otte <otte@gnome.org>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library 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 GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA  02110-1301  USA
  18  */
  19
  20 #ifndef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include <swfdec_sound_matrix.h>
  25 #include <liboil/liboil.h>
  26 #include <swfdec_debug.h>
  27
  28 void
  29 swfdec_sound_matrix_init_identity (SwfdecSoundMatrix *sound)
  30 {
  31   sound->ll = sound->rr = sound->volume = 100;
  32   sound->lr = sound->rl = 0;
  33 }
  34
  35 int
  36 swfdec_sound_matrix_get_pan (const SwfdecSoundMatrix *sound)
  37 {
  38   g_return_val_if_fail (sound != NULL, 0);
  39
  40   if (sound->ll == 100)
  41     return ABS (sound->rr) - 100;
  42   else
  43     return 100 - ABS (sound->ll);
  44 }
  45
  46 void
  47 swfdec_sound_matrix_set_pan (SwfdecSoundMatrix *sound, int pan)
  48 {
  49   g_return_if_fail (sound != NULL);
  50
  51   if (pan > 0) {
  52     sound->rr = 100;
  53     sound->ll = 100 - pan;
  54   } else {
  55     sound->ll = 100;
  56     sound->rr = 100 + pan;
  57   }
  58   sound->lr = 0;
  59   sound->rl = 0;
  60 }
  61
  62 gboolean
  63 swfdec_sound_matrix_is_identity (const SwfdecSoundMatrix *sound)
  64 {
  65   g_return_val_if_fail (sound != NULL, FALSE);
  66
  67   return sound->ll == 100 && sound->rr == 100 &&
  68     sound->lr == 0 && sound->rl == 0 && sound->volume == 100;
  69 }
  70
  71 gboolean
  72 swfdec_sound_matrix_is_equal (const SwfdecSoundMatrix *a, const SwfdecSoundMatrix *b)
  73 {
  74   g_return_val_if_fail (a != NULL, FALSE);
  75   g_return_val_if_fail (b != NULL, FALSE);
  76
  77   return a->ll == b->ll && a->rr == b->rr &&
  78     a->lr == b->lr && a->rl == b->rl && a->volume == b->volume;
  79 }
  80
  81 void
  82 swfdec_sound_matrix_apply (const SwfdecSoundMatrix *sound,
  83     gint16 *dest, guint n_samples)
  84 {
  85   guint i;
  86   int left, right;
  87
  88   if (swfdec_sound_matrix_is_identity (sound))
  89     return;
  90   for (i = 0; i < n_samples; i++) {
  91     left = (sound->ll * dest[0] + sound->lr * dest[1]) / 100;
  92     left *= sound->volume / 100;
  93     right = (sound->rl * dest[0] + sound->rr * dest[1]) / 100;
  94     right *= sound->volume / 100;
  95     dest[0] = left;
  96     dest[1] = right;
  97     dest += 2;
  98   }
  99 }
 100
 101
 102 void
 103 swfdec_sound_matrix_multiply (SwfdecSoundMatrix *dest,
 104     const SwfdecSoundMatrix *a, const SwfdecSoundMatrix *b)
 105 {
 106   int ll, lr, rl, rr;
 107
 108   g_return_if_fail (dest != NULL);
 109   g_return_if_fail (a != NULL);
 110   g_return_if_fail (b != NULL);
 111
 112   ll = (b->ll * a->ll + b->lr * a->rl) / 100;
 113   rl = (b->rl * a->ll + b->rr * a->rl) / 100;
 114   lr = (b->ll * a->lr + b->lr * a->rr) / 100;
 115   rr = (b->rl * a->lr + b->rr * a->rr) / 100;
 116
 117   dest->volume = b->volume * a->volume / 100;
 118   dest->ll = ll;
 119   dest->rl = rl;
 120   dest->lr = lr;
 121   dest->rr = rr;
 122 }
 123