Mon Mar 12 2012 21:40:05

Asterisk developer's documentation


func_volume.c File Reference

Technology independent volume control. More...

#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/utils.h"
#include "asterisk/audiohook.h"
#include "asterisk/app.h"
Include dependency graph for func_volume.c:

Go to the source code of this file.

Data Structures

struct  volume_information

Enumerations

enum  volume_flags { VOLUMEFLAG_CHANGE = (1 << 1) }

Functions

static void __reg_module (void)
static void __unreg_module (void)
static void destroy_callback (void *data)
static int load_module (void)
static int unload_module (void)
static int volume_callback (struct ast_audiohook *audiohook, struct ast_channel *chan, struct ast_frame *frame, enum ast_audiohook_direction direction)
static int volume_write (struct ast_channel *chan, const char *cmd, char *data, const char *value)

Variables

static struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "Technology independent volume control" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_DEFAULT, }
static struct ast_module_infoast_module_info = &__mod_info
static struct ast_datastore_info volume_datastore
 Static structure for datastore information.
static struct ast_custom_function volume_function
static struct ast_app_option volume_opts [128] = { [ 'p' ] = { .flag = VOLUMEFLAG_CHANGE },}

Detailed Description

Technology independent volume control.

Author:
Joshua Colp <jcolp@digium.com>

Definition in file func_volume.c.


Enumeration Type Documentation

Enumerator:
VOLUMEFLAG_CHANGE 

Definition at line 80 of file func_volume.c.

                  {
   VOLUMEFLAG_CHANGE = (1 << 1),
};

Function Documentation

static void __reg_module ( void  ) [static]

Definition at line 233 of file func_volume.c.

static void __unreg_module ( void  ) [static]

Definition at line 233 of file func_volume.c.

static void destroy_callback ( void *  data) [static]

Definition at line 88 of file func_volume.c.

References ast_audiohook_destroy(), ast_free, and volume_information::audiohook.

{
   struct volume_information *vi = data;

   /* Destroy the audiohook, and destroy ourselves */
   ast_audiohook_destroy(&vi->audiohook);
   ast_free(vi);

   return;
}
static int load_module ( void  ) [static]

Definition at line 228 of file func_volume.c.

References ast_custom_function_register.

static int unload_module ( void  ) [static]
static int volume_callback ( struct ast_audiohook audiohook,
struct ast_channel chan,
struct ast_frame frame,
enum ast_audiohook_direction  direction 
) [static]

Definition at line 105 of file func_volume.c.

References AST_AUDIOHOOK_DIRECTION_READ, AST_AUDIOHOOK_STATUS_DONE, ast_channel_datastore_find(), ast_frame_adjust_volume(), AST_FRAME_DTMF, AST_FRAME_VOICE, ast_test_flag, ast_datastore::data, ast_frame::frametype, ast_frame_subclass::integer, volume_information::rx_gain, ast_audiohook::status, ast_frame::subclass, volume_information::tx_gain, and VOLUMEFLAG_CHANGE.

Referenced by volume_write().

{
   struct ast_datastore *datastore = NULL;
   struct volume_information *vi = NULL;
   int *gain = NULL;

   /* If the audiohook is stopping it means the channel is shutting down.... but we let the datastore destroy take care of it */
   if (audiohook->status == AST_AUDIOHOOK_STATUS_DONE)
      return 0;

   /* Grab datastore which contains our gain information */
   if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL)))
      return 0;

   vi = datastore->data;

   /* If this is DTMF then allow them to increase/decrease the gains */
   if (ast_test_flag(vi, VOLUMEFLAG_CHANGE)) {
      if (frame->frametype == AST_FRAME_DTMF) {
         /* Only use DTMF coming from the source... not going to it */
         if (direction != AST_AUDIOHOOK_DIRECTION_READ)
            return 0; 
         if (frame->subclass.integer == '*') {
            vi->tx_gain += 1;
            vi->rx_gain += 1;
         } else if (frame->subclass.integer == '#') {
            vi->tx_gain -= 1;
            vi->rx_gain -= 1;
         }
      }
   }

   
   if (frame->frametype == AST_FRAME_VOICE) {
      /* Based on direction of frame grab the gain, and confirm it is applicable */
      if (!(gain = (direction == AST_AUDIOHOOK_DIRECTION_READ) ? &vi->rx_gain : &vi->tx_gain) || !*gain)
         return 0;
      /* Apply gain to frame... easy as pi */
      ast_frame_adjust_volume(frame, *gain);
   }

   return 0;
}
static int volume_write ( struct ast_channel chan,
const char *  cmd,
char *  data,
const char *  value 
) [static]

Definition at line 149 of file func_volume.c.

References args, AST_APP_ARG, ast_app_parse_options(), ast_audiohook_attach(), ast_audiohook_init(), AST_AUDIOHOOK_TYPE_MANIPULATE, AST_AUDIOHOOK_WANTS_DTMF, ast_calloc, ast_channel_datastore_add(), ast_channel_datastore_find(), ast_channel_lock, ast_channel_unlock, ast_datastore_alloc(), ast_datastore_free(), AST_DECLARE_APP_ARGS, ast_log(), ast_set_flag, AST_STANDARD_APP_ARGS, ast_strlen_zero(), volume_information::audiohook, ast_datastore::data, volume_information::flags, ast_flags::flags, LOG_ERROR, ast_audiohook::manipulate_callback, volume_information::rx_gain, volume_information::tx_gain, volume_callback(), and volume_opts.

{
   struct ast_datastore *datastore = NULL;
   struct volume_information *vi = NULL;
   int is_new = 0;

   /* Separate options from argument */
   
   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(direction);
      AST_APP_ARG(options);
   );
   
   AST_STANDARD_APP_ARGS(args, data);

   ast_channel_lock(chan);
   if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL))) {
      ast_channel_unlock(chan);
      /* Allocate a new datastore to hold the reference to this volume and audiohook information */
      if (!(datastore = ast_datastore_alloc(&volume_datastore, NULL)))
         return 0;
      if (!(vi = ast_calloc(1, sizeof(*vi)))) {
         ast_datastore_free(datastore);
         return 0;
      }
      ast_audiohook_init(&vi->audiohook, AST_AUDIOHOOK_TYPE_MANIPULATE, "Volume");
      vi->audiohook.manipulate_callback = volume_callback;
      ast_set_flag(&vi->audiohook, AST_AUDIOHOOK_WANTS_DTMF);
      is_new = 1;
   } else {
      ast_channel_unlock(chan);
      vi = datastore->data;
   }

   /* Adjust gain on volume information structure */
   if (ast_strlen_zero(args.direction)) {
      ast_log(LOG_ERROR, "Direction must be specified for VOLUME function\n");
      return -1;
   }

   if (!strcasecmp(args.direction, "tx")) { 
      vi->tx_gain = atoi(value); 
   } else if (!strcasecmp(args.direction, "rx")) {
      vi->rx_gain = atoi(value);
   } else {
      ast_log(LOG_ERROR, "Direction must be either RX or TX\n");
   }

   if (is_new) {
      datastore->data = vi;
      ast_channel_lock(chan);
      ast_channel_datastore_add(chan, datastore);
      ast_channel_unlock(chan);
      ast_audiohook_attach(chan, &vi->audiohook);
   }

   /* Add Option data to struct */
   
   if (!ast_strlen_zero(args.options)) {
      struct ast_flags flags = { 0 };
      ast_app_parse_options(volume_opts, &flags, &data, args.options);
      vi->flags = flags.flags;
   } else { 
      vi->flags = 0; 
   }

   return 0;
}

Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "Technology independent volume control" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_DEFAULT, } [static]

Definition at line 233 of file func_volume.c.

Definition at line 233 of file func_volume.c.

Initial value:
 {
   .type = "volume",
   .destroy = destroy_callback
}

Static structure for datastore information.

Definition at line 100 of file func_volume.c.

Initial value:
 {
   .name = "VOLUME",
   .write = volume_write,
}

Definition at line 218 of file func_volume.c.

struct ast_app_option volume_opts[128] = { [ 'p' ] = { .flag = VOLUMEFLAG_CHANGE },} [static]

Definition at line 86 of file func_volume.c.

Referenced by volume_write().