funcs/func_volume.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 2011, 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 /*** MODULEINFO
  30         <support_level>core</support_level>
  31  ***/
  32
  33 #include "asterisk.h"
  34
  35 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  36
  37 #include "asterisk/module.h"
  38 #include "asterisk/channel.h"
  39 #include "asterisk/pbx.h"
  40 #include "asterisk/utils.h"
  41 #include "asterisk/audiohook.h"
  42 #include "asterisk/app.h"
  43
  44 /*** DOCUMENTATION
  45         <function name="VOLUME" language="en_US">
  46                 <synopsis>
  47                         Set the TX or RX volume of a channel.
  48                 </synopsis>
  49                 <syntax>
  50                         <parameter name="direction" required="true">
  51                                 <para>Must be <literal>TX</literal> or <literal>RX</literal>.</para>
  52                         </parameter>
  53                         <parameter name="options">
  54                                 <optionlist>
  55                                         <option name="p">
  56                                                 <para>Enable DTMF volume control</para>
  57                                         </option>
  58                                 </optionlist>
  59                         </parameter>
  60                 </syntax>
  61                 <description>
  62                         <para>The VOLUME function can be used to increase or decrease the <literal>tx</literal> or
  63                         <literal>rx</literal> gain of any channel.</para>
  64                         <para>For example:</para>
  65                         <para>Set(VOLUME(TX)=3)</para>
  66                         <para>Set(VOLUME(RX)=2)</para>
  67                         <para>Set(VOLUME(TX,p)=3)</para>
  68                         <para>Set(VOLUME(RX,p)=3)</para>
  69                 </description>
  70         </function>
  71  ***/
  72
  73 struct volume_information {
  74         struct ast_audiohook audiohook;
  75         int tx_gain;
  76         int rx_gain;
  77         unsigned int flags;
  78 };
  79
  80 enum volume_flags {
  81         VOLUMEFLAG_CHANGE = (1 << 1),
  82 };
  83
  84 AST_APP_OPTIONS(volume_opts, {
  85         AST_APP_OPTION('p', VOLUMEFLAG_CHANGE),
  86 });
  87
  88 static void destroy_callback(void *data)
  89 {
  90         struct volume_information *vi = data;
  91
  92         /* Destroy the audiohook, and destroy ourselves */
  93         ast_audiohook_lock(&vi->audiohook);
  94         ast_audiohook_detach(&vi->audiohook);
  95         ast_audiohook_unlock(&vi->audiohook);
  96         ast_audiohook_destroy(&vi->audiohook);
  97         ast_free(vi);
  98
  99         return;
 100 }
 101
 102 /*! \brief Static structure for datastore information */
 103 static const struct ast_datastore_info volume_datastore = {
 104         .type = "volume",
 105         .destroy = destroy_callback
 106 };
 107
 108 static int volume_callback(struct ast_audiohook *audiohook, struct ast_channel *chan, struct ast_frame *frame, enum ast_audiohook_direction direction)
 109 {
 110         struct ast_datastore *datastore = NULL;
 111         struct volume_information *vi = NULL;
 112         int *gain = NULL;
 113
 114         /* If the audiohook is stopping it means the channel is shutting down.... but we let the datastore destroy take care of it */
 115         if (audiohook->status == AST_AUDIOHOOK_STATUS_DONE)
 116                 return 0;
 117
 118         /* Grab datastore which contains our gain information */
 119         if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL)))
 120                 return 0;
 121
 122         vi = datastore->data;
 123
 124         /* If this is DTMF then allow them to increase/decrease the gains */
 125         if (ast_test_flag(vi, VOLUMEFLAG_CHANGE)) {
 126                 if (frame->frametype == AST_FRAME_DTMF) {
 127                         /* Only use DTMF coming from the source... not going to it */
 128                         if (direction != AST_AUDIOHOOK_DIRECTION_READ)
 129                                 return 0;
 130                         if (frame->subclass.integer == '*') {
 131                                 vi->tx_gain += 1;
 132                                 vi->rx_gain += 1;
 133                         } else if (frame->subclass.integer == '#') {
 134                                 vi->tx_gain -= 1;
 135                                 vi->rx_gain -= 1;
 136                         }
 137                 }
 138         }
 139
 140
 141         if (frame->frametype == AST_FRAME_VOICE) {
 142                 /* Based on direction of frame grab the gain, and confirm it is applicable */
 143                 if (!(gain = (direction == AST_AUDIOHOOK_DIRECTION_READ) ? &vi->rx_gain : &vi->tx_gain) || !*gain)
 144                         return 0;
 145                 /* Apply gain to frame... easy as pi */
 146                 ast_frame_adjust_volume(frame, *gain);
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int volume_write(struct ast_channel *chan, const char *cmd, char *data, const char *value)
 153 {
 154         struct ast_datastore *datastore = NULL;
 155         struct volume_information *vi = NULL;
 156         int is_new = 0;
 157
 158         /* Separate options from argument */
 159
 160         AST_DECLARE_APP_ARGS(args,
 161                 AST_APP_ARG(direction);
 162                 AST_APP_ARG(options);
 163         );
 164
 165         AST_STANDARD_APP_ARGS(args, data);
 166
 167         ast_channel_lock(chan);
 168         if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL))) {
 169                 ast_channel_unlock(chan);
 170                 /* Allocate a new datastore to hold the reference to this volume and audiohook information */
 171                 if (!(datastore = ast_datastore_alloc(&volume_datastore, NULL)))
 172                         return 0;
 173                 if (!(vi = ast_calloc(1, sizeof(*vi)))) {
 174                         ast_datastore_free(datastore);
 175                         return 0;
 176                 }
 177                 ast_audiohook_init(&vi->audiohook, AST_AUDIOHOOK_TYPE_MANIPULATE, "Volume", AST_AUDIOHOOK_MANIPULATE_ALL_RATES);
 178                 vi->audiohook.manipulate_callback = volume_callback;
 179                 ast_set_flag(&vi->audiohook, AST_AUDIOHOOK_WANTS_DTMF);
 180                 is_new = 1;
 181         } else {
 182                 ast_channel_unlock(chan);
 183                 vi = datastore->data;
 184         }
 185
 186         /* Adjust gain on volume information structure */
 187         if (ast_strlen_zero(args.direction)) {
 188                 ast_log(LOG_ERROR, "Direction must be specified for VOLUME function\n");
 189                 return -1;
 190         }
 191
 192         if (!strcasecmp(args.direction, "tx")) {
 193                 vi->tx_gain = atoi(value);
 194         } else if (!strcasecmp(args.direction, "rx")) {
 195                 vi->rx_gain = atoi(value);
 196         } else {
 197                 ast_log(LOG_ERROR, "Direction must be either RX or TX\n");
 198         }
 199
 200         if (is_new) {
 201                 datastore->data = vi;
 202                 ast_channel_lock(chan);
 203                 ast_channel_datastore_add(chan, datastore);
 204                 ast_channel_unlock(chan);
 205                 ast_audiohook_attach(chan, &vi->audiohook);
 206         }
 207
 208         /* Add Option data to struct */
 209
 210         if (!ast_strlen_zero(args.options)) {
 211                 struct ast_flags flags = { 0 };
 212                 ast_app_parse_options(volume_opts, &flags, NULL, args.options);
 213                 vi->flags = flags.flags;
 214         } else {
 215                 vi->flags = 0;
 216         }
 217
 218         return 0;
 219 }
 220
 221 static struct ast_custom_function volume_function = {
 222         .name = "VOLUME",
 223         .write = volume_write,
 224 };
 225
 226 static int unload_module(void)
 227 {
 228         return ast_custom_function_unregister(&volume_function);
 229 }
 230
 231 static int load_module(void)
 232 {
 233         return ast_custom_function_register(&volume_function);
 234 }
 235
 236 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Technology independent volume control");