src/volume.c

   1 /*
   2  * Copyright (C) 2003-2010 The Music Player Daemon Project
   3  * http://www.musicpd.org
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #include "config.h"
  21 #include "volume.h"
  22 #include "conf.h"
  23 #include "player_control.h"
  24 #include "idle.h"
  25 #include "pcm_volume.h"
  26 #include "output_all.h"
  27 #include "mixer_control.h"
  28 #include "mixer_all.h"
  29 #include "mixer_type.h"
  30 #include "event_pipe.h"
  31
  32 #include <glib.h>
  33
  34 #include <assert.h>
  35 #include <math.h>
  36 #include <string.h>
  37 #include <stdlib.h>
  38
  39 #undef G_LOG_DOMAIN
  40 #define G_LOG_DOMAIN "volume"
  41
  42 #define SW_VOLUME_STATE                         "sw_volume: "
  43
  44 static unsigned volume_software_set = 100;
  45
  46 /** the cached hardware mixer value; invalid if negative */
  47 static int last_hardware_volume = -1;
  48 /** the age of #last_hardware_volume */
  49 static GTimer *hardware_volume_timer;
  50
  51 /**
  52  * Handler for #PIPE_EVENT_MIXER.
  53  */
  54 static void
  55 mixer_event_callback(void)
  56 {
  57         /* flush the hardware volume cache */
  58         last_hardware_volume = -1;
  59
  60         /* notify clients */
  61         idle_add(IDLE_MIXER);
  62 }
  63
  64 void volume_finish(void)
  65 {
  66         g_timer_destroy(hardware_volume_timer);
  67 }
  68
  69 void volume_init(void)
  70 {
  71         hardware_volume_timer = g_timer_new();
  72
  73         event_pipe_register(PIPE_EVENT_MIXER, mixer_event_callback);
  74 }
  75
  76 int volume_level_get(void)
  77 {
  78         assert(hardware_volume_timer != NULL);
  79
  80         if (last_hardware_volume >= 0 &&
  81             g_timer_elapsed(hardware_volume_timer, NULL) < 1.0)
  82                 /* throttle access to hardware mixers */
  83                 return last_hardware_volume;
  84
  85         last_hardware_volume = mixer_all_get_volume();
  86         g_timer_start(hardware_volume_timer);
  87         return last_hardware_volume;
  88 }
  89
  90 static bool software_volume_change(unsigned volume)
  91 {
  92         assert(volume <= 100);
  93
  94         volume_software_set = volume;
  95         mixer_all_set_software_volume(volume);
  96
  97         return true;
  98 }
  99
 100 static bool hardware_volume_change(unsigned volume)
 101 {
 102         /* reset the cache */
 103         last_hardware_volume = -1;
 104
 105         return mixer_all_set_volume(volume);
 106 }
 107
 108 bool volume_level_change(unsigned volume)
 109 {
 110         assert(volume <= 100);
 111
 112         volume_software_set = volume;
 113
 114         idle_add(IDLE_MIXER);
 115
 116         return hardware_volume_change(volume);
 117 }
 118
 119 bool
 120 read_sw_volume_state(const char *line)
 121 {
 122         char *end = NULL;
 123         long int sv;
 124
 125         if (!g_str_has_prefix(line, SW_VOLUME_STATE))
 126                 return false;
 127
 128         line += sizeof(SW_VOLUME_STATE) - 1;
 129         sv = strtol(line, &end, 10);
 130         if (*end == 0 && sv >= 0 && sv <= 100)
 131                 software_volume_change(sv);
 132         else
 133                 g_warning("Can't parse software volume: %s\n", line);
 134         return true;
 135 }
 136
 137 void save_sw_volume_state(FILE *fp)
 138 {
 139         fprintf(fp, SW_VOLUME_STATE "%u\n", volume_software_set);
 140 }
 141
 142 unsigned
 143 sw_volume_state_get_hash(void)
 144 {
 145         return volume_software_set;
 146 }