funcs/func_volume.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 2007, Digium, Inc.
   5  *
   6  * Joshua Colp <jcolp@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  *
  21  * \brief Technology independent volume control
  22  *
  23  * \author Joshua Colp <jcolp@digium.com>
  24  *
  25  * \ingroup functions
  26  *
  27  */
  28
  29 #include "asterisk.h"
  30
  31 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  32
  33 #include "asterisk/module.h"
  34 #include "asterisk/channel.h"
  35 #include "asterisk/pbx.h"
  36 #include "asterisk/utils.h"
  37 #include "asterisk/audiohook.h"
  38
  39 struct volume_information {
  40         struct ast_audiohook audiohook;
  41         int tx_gain;
  42         int rx_gain;
  43 };
  44
  45 static void destroy_callback(void *data)
  46 {
  47         struct volume_information *vi = data;
  48
  49         /* Destroy the audiohook, and destroy ourselves */
  50         ast_audiohook_destroy(&vi->audiohook);
  51         free(vi);
  52
  53         return;
  54 }
  55
  56 /*! \brief Static structure for datastore information */
  57 static const struct ast_datastore_info volume_datastore = {
  58         .type = "volume",
  59         .destroy = destroy_callback
  60 };
  61
  62 static int volume_callback(struct ast_audiohook *audiohook, struct ast_channel *chan, struct ast_frame *frame, enum ast_audiohook_direction direction)
  63 {
  64         struct ast_datastore *datastore = NULL;
  65         struct volume_information *vi = NULL;
  66         int *gain = NULL;
  67
  68         /* If the audiohook is stopping it means the channel is shutting down.... but we let the datastore destroy take care of it */
  69         if (audiohook->status == AST_AUDIOHOOK_STATUS_DONE)
  70                 return 0;
  71
  72         /* Grab datastore which contains our gain information */
  73         if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL)))
  74                 return 0;
  75
  76         vi = datastore->data;
  77
  78         /* If this is DTMF then allow them to increase/decrease the gains */
  79         if (frame->frametype == AST_FRAME_DTMF) {
  80                 /* Only use DTMF coming from the source... not going to it */
  81                 if (direction != AST_AUDIOHOOK_DIRECTION_READ)
  82                         return 0;
  83                 if (frame->subclass == '*') {
  84                         vi->tx_gain += 1;
  85                         vi->rx_gain += 1;
  86                 } else if (frame->subclass == '#') {
  87                         vi->tx_gain -= 1;
  88                         vi->rx_gain -= 1;
  89                 }
  90         } else if (frame->frametype == AST_FRAME_VOICE) {
  91                 /* Based on direction of frame grab the gain, and confirm it is applicable */
  92                 if (!(gain = (direction == AST_AUDIOHOOK_DIRECTION_READ) ? &vi->rx_gain : &vi->tx_gain) || !*gain)
  93                         return 0;
  94                 /* Apply gain to frame... easy as pi */
  95                 ast_frame_adjust_volume(frame, *gain);
  96         }
  97
  98         return 0;
  99 }
 100
 101 static int volume_write(struct ast_channel *chan, const char *cmd, char *data, const char *value)
 102 {
 103         struct ast_datastore *datastore = NULL;
 104         struct volume_information *vi = NULL;
 105         int is_new = 0;
 106
 107         if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL))) {
 108                 /* Allocate a new datastore to hold the reference to this volume and audiohook information */
 109                 if (!(datastore = ast_channel_datastore_alloc(&volume_datastore, NULL)))
 110                         return 0;
 111                 if (!(vi = ast_calloc(1, sizeof(*vi)))) {
 112                         ast_channel_datastore_free(datastore);
 113                         return 0;
 114                 }
 115                 ast_audiohook_init(&vi->audiohook, AST_AUDIOHOOK_TYPE_MANIPULATE, "Volume");
 116                 vi->audiohook.manipulate_callback = volume_callback;
 117                 ast_set_flag(&vi->audiohook, AST_AUDIOHOOK_WANTS_DTMF);
 118                 is_new = 1;
 119         } else {
 120                 vi = datastore->data;
 121         }
 122
 123         /* Adjust gain on volume information structure */
 124         if (!strcasecmp(data, "tx"))
 125                 vi->tx_gain = atoi(value);
 126         else if (!strcasecmp(data, "rx"))
 127                 vi->rx_gain = atoi(value);
 128
 129         if (is_new) {
 130                 datastore->data = vi;
 131                 ast_channel_datastore_add(chan, datastore);
 132                 ast_audiohook_attach(chan, &vi->audiohook);
 133         }
 134
 135         return 0;
 136 }
 137
 138 static struct ast_custom_function volume_function = {
 139         .name = "VOLUME",
 140         .synopsis = "Set the TX or RX volume of a channel",
 141         .syntax = "VOLUME(TX|RX)",
 142         .desc =
 143         "  The VOLUME function can be used to increase or decrease the tx or\n"
 144         "rx gain of any channel.  For example:\n"
 145         "  Set(VOLUME(TX)=3)\n"
 146         "  Set(VOLUME(RX)=2)\n",
 147         .write = volume_write,
 148 };
 149
 150 static int unload_module(void)
 151 {
 152         return ast_custom_function_unregister(&volume_function);
 153 }
 154
 155 static int load_module(void)
 156 {
 157         return ast_custom_function_register(&volume_function);
 158 }
 159
 160 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Technology independent volume control");