Tue Aug 24 2010 19:41:53

Asterisk developer's documentation


Data Structures | Functions | Variables

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 dependency graph for func_volume.c:

Go to the source code of this file.

Data Structures

struct  volume_information

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_DEFAULT , .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 = "0901e4e500243c855563a2d78b0c03e4" , .load = load_module, .unload = unload_module, }
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

Detailed Description

Technology independent volume control.

Author:
Joshua Colp <jcolp@digium.com>

Definition in file func_volume.c.


Function Documentation

static void __reg_module ( void   )  [static]

Definition at line 173 of file func_volume.c.

static void __unreg_module ( void   )  [static]

Definition at line 173 of file func_volume.c.

static void destroy_callback ( void *  data  )  [static]

Definition at line 65 of file func_volume.c.

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

{
   struct volume_information *vi = data;

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

   return;
}

static int load_module ( void   )  [static]

Definition at line 168 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 82 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_datastore::data, ast_frame::frametype, volume_information::rx_gain, ast_audiohook::status, ast_frame::subclass, and volume_information::tx_gain.

{
   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 (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 == '*') {
         vi->tx_gain += 1;
         vi->rx_gain += 1;
      } else if (frame->subclass == '#') {
         vi->tx_gain -= 1;
         vi->rx_gain -= 1;
      }
   } else 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 121 of file func_volume.c.

References 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_datastore_alloc(), ast_datastore_free(), ast_set_flag, volume_information::audiohook, ast_datastore::data, ast_audiohook::manipulate_callback, volume_information::rx_gain, and volume_information::tx_gain.

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

   if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL))) {
      /* 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 {
      vi = datastore->data;
   }

   /* Adjust gain on volume information structure */
   if (!strcasecmp(data, "tx"))
      vi->tx_gain = atoi(value);
   else if (!strcasecmp(data, "rx"))
      vi->rx_gain = atoi(value);

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

   return 0;
}


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .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 = "0901e4e500243c855563a2d78b0c03e4" , .load = load_module, .unload = unload_module, } [static]

Definition at line 173 of file func_volume.c.

Definition at line 173 of file func_volume.c.

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

Static structure for datastore information.

Definition at line 77 of file func_volume.c.

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

Definition at line 158 of file func_volume.c.