Mon Mar 19 11:30:48 2012

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"

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 = "88eaa8f5c1bd988bedd71113385e0886" , .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

enum volume_flags

Enumerator:
VOLUMEFLAG_CHANGE 

Definition at line 80 of file func_volume.c.

00080                   {
00081    VOLUMEFLAG_CHANGE = (1 << 1),
00082 };


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.

00089 {
00090    struct volume_information *vi = data;
00091 
00092    /* Destroy the audiohook, and destroy ourselves */
00093    ast_audiohook_destroy(&vi->audiohook);
00094    ast_free(vi);
00095 
00096    return;
00097 }

static int load_module ( void   )  [static]

Definition at line 228 of file func_volume.c.

References ast_custom_function_register, and volume_function.

00229 {
00230    return ast_custom_function_register(&volume_function);
00231 }

static int unload_module ( void   )  [static]

Definition at line 223 of file func_volume.c.

References ast_custom_function_unregister(), and volume_function.

00224 {
00225    return ast_custom_function_unregister(&volume_function);
00226 }

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, 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, volume_datastore, and VOLUMEFLAG_CHANGE.

Referenced by volume_write().

00106 {
00107    struct ast_datastore *datastore = NULL;
00108    struct volume_information *vi = NULL;
00109    int *gain = NULL;
00110 
00111    /* If the audiohook is stopping it means the channel is shutting down.... but we let the datastore destroy take care of it */
00112    if (audiohook->status == AST_AUDIOHOOK_STATUS_DONE)
00113       return 0;
00114 
00115    /* Grab datastore which contains our gain information */
00116    if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL)))
00117       return 0;
00118 
00119    vi = datastore->data;
00120 
00121    /* If this is DTMF then allow them to increase/decrease the gains */
00122    if (ast_test_flag(vi, VOLUMEFLAG_CHANGE)) {
00123       if (frame->frametype == AST_FRAME_DTMF) {
00124          /* Only use DTMF coming from the source... not going to it */
00125          if (direction != AST_AUDIOHOOK_DIRECTION_READ)
00126             return 0; 
00127          if (frame->subclass.integer == '*') {
00128             vi->tx_gain += 1;
00129             vi->rx_gain += 1;
00130          } else if (frame->subclass.integer == '#') {
00131             vi->tx_gain -= 1;
00132             vi->rx_gain -= 1;
00133          }
00134       }
00135    }
00136 
00137    
00138    if (frame->frametype == AST_FRAME_VOICE) {
00139       /* Based on direction of frame grab the gain, and confirm it is applicable */
00140       if (!(gain = (direction == AST_AUDIOHOOK_DIRECTION_READ) ? &vi->rx_gain : &vi->tx_gain) || !*gain)
00141          return 0;
00142       /* Apply gain to frame... easy as pi */
00143       ast_frame_adjust_volume(frame, *gain);
00144    }
00145 
00146    return 0;
00147 }

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

00150 {
00151    struct ast_datastore *datastore = NULL;
00152    struct volume_information *vi = NULL;
00153    int is_new = 0;
00154 
00155    /* Separate options from argument */
00156    
00157    AST_DECLARE_APP_ARGS(args,
00158       AST_APP_ARG(direction);
00159       AST_APP_ARG(options);
00160    );
00161    
00162    AST_STANDARD_APP_ARGS(args, data);
00163 
00164    ast_channel_lock(chan);
00165    if (!(datastore = ast_channel_datastore_find(chan, &volume_datastore, NULL))) {
00166       ast_channel_unlock(chan);
00167       /* Allocate a new datastore to hold the reference to this volume and audiohook information */
00168       if (!(datastore = ast_datastore_alloc(&volume_datastore, NULL)))
00169          return 0;
00170       if (!(vi = ast_calloc(1, sizeof(*vi)))) {
00171          ast_datastore_free(datastore);
00172          return 0;
00173       }
00174       ast_audiohook_init(&vi->audiohook, AST_AUDIOHOOK_TYPE_MANIPULATE, "Volume");
00175       vi->audiohook.manipulate_callback = volume_callback;
00176       ast_set_flag(&vi->audiohook, AST_AUDIOHOOK_WANTS_DTMF);
00177       is_new = 1;
00178    } else {
00179       ast_channel_unlock(chan);
00180       vi = datastore->data;
00181    }
00182 
00183    /* Adjust gain on volume information structure */
00184    if (ast_strlen_zero(args.direction)) {
00185       ast_log(LOG_ERROR, "Direction must be specified for VOLUME function\n");
00186       return -1;
00187    }
00188 
00189    if (!strcasecmp(args.direction, "tx")) { 
00190       vi->tx_gain = atoi(value); 
00191    } else if (!strcasecmp(args.direction, "rx")) {
00192       vi->rx_gain = atoi(value);
00193    } else {
00194       ast_log(LOG_ERROR, "Direction must be either RX or TX\n");
00195    }
00196 
00197    if (is_new) {
00198       datastore->data = vi;
00199       ast_channel_lock(chan);
00200       ast_channel_datastore_add(chan, datastore);
00201       ast_channel_unlock(chan);
00202       ast_audiohook_attach(chan, &vi->audiohook);
00203    }
00204 
00205    /* Add Option data to struct */
00206    
00207    if (!ast_strlen_zero(args.options)) {
00208       struct ast_flags flags = { 0 };
00209       ast_app_parse_options(volume_opts, &flags, &data, args.options);
00210       vi->flags = flags.flags;
00211    } else { 
00212       vi->flags = 0; 
00213    }
00214 
00215    return 0;
00216 }


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 = "88eaa8f5c1bd988bedd71113385e0886" , .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_DEFAULT, } [static]

Definition at line 233 of file func_volume.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 233 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 100 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 218 of file func_volume.c.

Referenced by load_module(), and unload_module().

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().


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