Mon Mar 12 2012 21:38:14

Asterisk developer's documentation

Defines | Functions | Variables
codec_alaw.c File Reference
Module: Codecs

codec_alaw.c - translate between signed linear and alaw More...

#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/config.h"
#include "asterisk/translate.h"
#include "asterisk/alaw.h"
#include "asterisk/utils.h"
#include "asterisk/slin.h"
#include "ex_alaw.h"
Include dependency graph for codec_alaw.c:

Go to the source code of this file.

Defines

#define BUFFER_SAMPLES   8096

Functions

static void __reg_module (void)
static void __unreg_module (void)
static int alawtolin_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
 decode frame into lin and fill output buffer.
static int lintoalaw_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
 convert and store input samples in output buffer
static int load_module (void)
static int reload (void)
 standard module stuff
static int unload_module (void)

Variables

static struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "A-law Coder/Decoder" , .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, .reload = reload, }
static struct ast_translator alawtolin
static struct ast_module_info * ast_module_info = &__mod_info
static struct ast_translator lintoalaw

Detailed Description

codec_alaw.c - translate between signed linear and alaw

Definition in file codec_alaw.c.

Define Documentation

#define BUFFER_SAMPLES   8096

Definition at line 40 of file codec_alaw.c.

Function Documentation

static void __reg_module ( void  ) [static]

Definition at line 133 of file codec_alaw.c.

static void __unreg_module ( void  ) [static]

Definition at line 133 of file codec_alaw.c.

static int alawtolin_framein ( struct ast_trans_pvt *  pvt,
struct ast_frame *  f 
) [static]

decode frame into lin and fill output buffer.

Definition at line 47 of file codec_alaw.c.

References AST_ALAW, ast_frame::data, ast_trans_pvt::datalen, ast_trans_pvt::i16, ast_trans_pvt::outbuf, ast_frame::ptr, ast_trans_pvt::samples, and ast_frame::samples.

{
   int i = f->samples;
   unsigned char *src = f->data.ptr;
   int16_t *dst = pvt->outbuf.i16 + pvt->samples;

   pvt->samples += i;
   pvt->datalen += i * 2;  /* 2 bytes/sample */
   
   while (i--)
      *dst++ = AST_ALAW(*src++);

   return 0;
}
static int lintoalaw_framein ( struct ast_trans_pvt *  pvt,
struct ast_frame *  f 
) [static]

convert and store input samples in output buffer

Definition at line 63 of file codec_alaw.c.

References AST_LIN2A, ast_trans_pvt::c, ast_frame::data, ast_trans_pvt::datalen, ast_trans_pvt::outbuf, ast_frame::ptr, ast_trans_pvt::samples, and ast_frame::samples.

{
   int i = f->samples;
   char *dst = pvt->outbuf.c + pvt->samples;
   int16_t *src = f->data.ptr;

   pvt->samples += i;
   pvt->datalen += i;   /* 1 byte/sample */

   while (i--) 
      *dst++ = AST_LIN2A(*src++);

   return 0;
}
static int load_module ( void  ) [static]

Definition at line 115 of file codec_alaw.c.

References AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_SUCCESS, ast_register_translator, and ast_unregister_translator().

{
   int res;

   res = ast_register_translator(&alawtolin);
   if (!res)
      res = ast_register_translator(&lintoalaw);
   else
      ast_unregister_translator(&alawtolin);
   if (res)
      return AST_MODULE_LOAD_FAILURE;
   return AST_MODULE_LOAD_SUCCESS;
}
static int reload ( void  ) [static]

standard module stuff

Definition at line 100 of file codec_alaw.c.

References AST_MODULE_LOAD_SUCCESS.

{
   return AST_MODULE_LOAD_SUCCESS;
}
static int unload_module ( void  ) [static]

Definition at line 105 of file codec_alaw.c.

References ast_unregister_translator().

{
   int res;

   res = ast_unregister_translator(&lintoalaw);
   res |= ast_unregister_translator(&alawtolin);

   return res;
}

Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "A-law Coder/Decoder" , .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, .reload = reload, } [static]

Definition at line 133 of file codec_alaw.c.

struct ast_translator alawtolin [static]

Definition at line 78 of file codec_alaw.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 133 of file codec_alaw.c.

struct ast_translator lintoalaw [static]

Definition at line 88 of file codec_alaw.c.