Mon Jun 27 16:51:15 2011

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"

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_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 = "8586c2a7d357cb591cc3a6607a8f62d1" , .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


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(), ast_free, and volume_information::audiohook.

00066 {
00067    struct volume_information *vi = data;
00068 
00069    /* Destroy the audiohook, and destroy ourselves */
00070    ast_audiohook_destroy(&vi->audiohook);
00071    ast_free(vi);
00072 
00073    return;
00074 }

static int load_module ( void   )  [static]

Definition at line 168 of file func_volume.c.

References ast_custom_function_register, and volume_function.

00169 {
00170    return ast_custom_function_register(&volume_function);
00171 }

static int unload_module ( void   )  [static]

Definition at line 163 of file func_volume.c.

References ast_custom_function_unregister(), and volume_function.

00164 {
00165    return ast_custom_function_unregister(&volume_function);
00166 }

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, volume_information::audiohook, 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 volume_datastore.

Referenced by volume_write().

00083 {
00084    struct ast_datastore *datastore = NULL;
00085    struct volume_information *vi = NULL;
00086    int *gain = NULL;
00087 
00088    /* If the audiohook is stopping it means the channel is shutting down.... but we let the datastore destroy take care of it */
00089    if (audiohook->status == AST_AUDIOHOOK_STATUS_DONE)
00090       return 0;
00091 
00092    /* Grab datastore which contains our gain information */
00093    if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL)))
00094       return 0;
00095 
00096    vi = datastore->data;
00097 
00098    /* If this is DTMF then allow them to increase/decrease the gains */
00099    if (frame->frametype == AST_FRAME_DTMF) {
00100       /* Only use DTMF coming from the source... not going to it */
00101       if (direction != AST_AUDIOHOOK_DIRECTION_READ)
00102          return 0;
00103       if (frame->subclass.integer == '*') {
00104          vi->tx_gain += 1;
00105          vi->rx_gain += 1;
00106       } else if (frame->subclass.integer == '#') {
00107          vi->tx_gain -= 1;
00108          vi->rx_gain -= 1;
00109       }
00110    } else if (frame->frametype == AST_FRAME_VOICE) {
00111       /* Based on direction of frame grab the gain, and confirm it is applicable */
00112       if (!(gain = (direction == AST_AUDIOHOOK_DIRECTION_READ) ? &vi->rx_gain : &vi->tx_gain) || !*gain)
00113          return 0;
00114       /* Apply gain to frame... easy as pi */
00115       ast_frame_adjust_volume(frame, *gain);
00116    }
00117 
00118    return 0;
00119 }

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, volume_information::rx_gain, volume_information::tx_gain, volume_callback(), and volume_datastore.

00122 {
00123    struct ast_datastore *datastore = NULL;
00124    struct volume_information *vi = NULL;
00125    int is_new = 0;
00126 
00127    if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL))) {
00128       /* Allocate a new datastore to hold the reference to this volume and audiohook information */
00129       if (!(datastore = ast_datastore_alloc(&volume_datastore, NULL)))
00130          return 0;
00131       if (!(vi = ast_calloc(1, sizeof(*vi)))) {
00132          ast_datastore_free(datastore);
00133          return 0;
00134       }
00135       ast_audiohook_init(&vi->audiohook, AST_AUDIOHOOK_TYPE_MANIPULATE, "Volume");
00136       vi->audiohook.manipulate_callback = volume_callback;
00137       ast_set_flag(&vi->audiohook, AST_AUDIOHOOK_WANTS_DTMF);
00138       is_new = 1;
00139    } else {
00140       vi = datastore->data;
00141    }
00142 
00143    /* Adjust gain on volume information structure */
00144    if (!strcasecmp(data, "tx"))
00145       vi->tx_gain = atoi(value);
00146    else if (!strcasecmp(data, "rx"))
00147       vi->rx_gain = atoi(value);
00148 
00149    if (is_new) {
00150       datastore->data = vi;
00151       ast_channel_datastore_add(chan, datastore);
00152       ast_audiohook_attach(chan, &vi->audiohook);
00153    }
00154 
00155    return 0;
00156 }


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 = "8586c2a7d357cb591cc3a6607a8f62d1" , .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_DEFAULT, } [static]

Definition at line 173 of file func_volume.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 173 of file func_volume.c.

struct ast_datastore_info volume_datastore [static]

Initial value:

 {
   .type = "volume",
   .destroy = destroy_callback
}
Static structure for datastore information.

Definition at line 77 of file func_volume.c.

Referenced by volume_callback(), and volume_write().

struct ast_custom_function volume_function [static]

Initial value:

 {
   .name = "VOLUME",
   .write = volume_write,
}

Definition at line 158 of file func_volume.c.

Referenced by load_module(), and unload_module().


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