code.delx.au - pulseaudio/blob - src/polyp/volume.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of polypaudio.
   5
   6   polypaudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as published
   8   by the Free Software Foundation; either version 2 of the License,
   9   or (at your option) any later version.
  10
  11   polypaudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with polypaudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <assert.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29
  30 #include "volume.h"
  31
  32 int pa_cvolume_equal(const pa_cvolume *a, const pa_cvolume *b) {
  33     int i;
  34     assert(a);
  35     assert(b);
  36
  37     if (a->channels != b->channels)
  38         return 0;
  39
  40     for (i = 0; i < a->channels; i++)
  41         if (a->values[i] != b->values[i])
  42             return 0;
  43
  44     return 1;
  45 }
  46
  47 pa_cvolume* pa_cvolume_set(pa_cvolume *a, unsigned channels, pa_volume_t v) {
  48     int i;
  49
  50     assert(a);
  51     assert(channels > 0);
  52     assert(channels <= PA_CHANNELS_MAX);
  53
  54     a->channels = channels;
  55
  56     for (i = 0; i < a->channels; i++)
  57         a->values[i] = v;
  58
  59     return a;
  60 }
  61
  62 pa_volume_t pa_cvolume_avg(const pa_cvolume *a) {
  63     uint64_t sum = 0;
  64     int i;
  65     assert(a);
  66
  67     for (i = 0; i < a->channels; i++)
  68         sum += a->values[i];
  69
  70     sum /= a->channels;
  71
  72     return (pa_volume_t) sum;
  73 }
  74
  75 pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b) {
  76     return pa_sw_volume_from_linear(pa_sw_volume_to_linear(a)* pa_sw_volume_to_linear(b));
  77 }
  78
  79 #define USER_DECIBEL_RANGE 30
  80
  81 pa_volume_t pa_sw_volume_from_dB(double dB) {
  82     if (dB <= -USER_DECIBEL_RANGE)
  83         return PA_VOLUME_MUTED;
  84
  85     return (pa_volume_t) ((dB/USER_DECIBEL_RANGE+1)*PA_VOLUME_NORM);
  86 }
  87
  88 double pa_sw_volume_to_dB(pa_volume_t v) {
  89     if (v == PA_VOLUME_MUTED)
  90         return PA_DECIBEL_MININFTY;
  91
  92     return ((double) v/PA_VOLUME_NORM-1)*USER_DECIBEL_RANGE;
  93 }
  94
  95 pa_volume_t pa_sw_volume_from_linear(double v) {
  96
  97     if (v <= 0)
  98         return PA_VOLUME_MUTED;
  99
 100     if (v > .999 && v < 1.001)
 101         return PA_VOLUME_NORM;
 102
 103     return pa_sw_volume_from_dB(20*log10(v));
 104 }
 105
 106 double pa_sw_volume_to_linear(pa_volume_t v) {
 107
 108     if (v == PA_VOLUME_MUTED)
 109         return 0;
 110
 111     return pow(10, pa_sw_volume_to_dB(v)/20);
 112 }
 113
 114 char *pa_cvolume_snprint(char *s, size_t l, const pa_cvolume *c) {
 115     unsigned channel;
 116     int first = 1;
 117     char *e;
 118
 119     assert(s);
 120     assert(l > 0);
 121     assert(c);
 122
 123     *(e = s) = 0;
 124
 125     for (channel = 0; channel < c->channels && l > 1; channel++) {
 126         l -= snprintf(e, l, "%s%u: %3u%%",
 127                       first ? "" : " ",
 128                       channel,
 129                       (c->values[channel]*100)/PA_VOLUME_NORM);
 130
 131         e = strchr(e, 0);
 132         first = 0;
 133     }
 134
 135     return s;
 136 }
 137
 138 /** Return non-zero if the volume of all channels is equal to the specified value */
 139 int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v) {
 140     unsigned c;
 141     assert(a);
 142
 143     for (c = 0; c < a->channels; c++)
 144         if (a->values[c] != v)
 145             return 0;
 146
 147     return 1;
 148 }
 149
 150 pa_cvolume *pa_sw_cvolume_multiply(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b) {
 151     unsigned i;
 152
 153     assert(dest);
 154     assert(a);
 155     assert(b);
 156
 157     for (i = 0; i < a->channels && i < b->channels && i < PA_CHANNELS_MAX; i++) {
 158
 159         dest->values[i] = pa_sw_volume_multiply(
 160             i < a->channels ? a->values[i] : PA_VOLUME_NORM,
 161             i < b->channels ? b->values[i] : PA_VOLUME_NORM);
 162     }
 163
 164     dest->channels = i;
 165
 166     return dest;
 167 }
 168
 169 int pa_cvolume_valid(const pa_cvolume *v) {
 170     assert(v);
 171
 172     if (v->channels <= 0 || v->channels > PA_CHANNELS_MAX)
 173         return 0;
 174
 175     return 1;
 176 }