Sat Aug 6 00:39:54 2011

Asterisk developer's documentation


codec_ulaw.c File Reference

codec_ulaw.c - translate between signed linear and ulaw More...

#include "asterisk.h"
#include <fcntl.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "asterisk/lock.h"
#include "asterisk/logger.h"
#include "asterisk/module.h"
#include "asterisk/config.h"
#include "asterisk/options.h"
#include "asterisk/translate.h"
#include "asterisk/channel.h"
#include "asterisk/ulaw.h"
#include "asterisk/utils.h"
#include "slin_ulaw_ex.h"
#include "ulaw_slin_ex.h"

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 lintoulaw_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
 convert and store samples in outbuf
static struct ast_framelintoulaw_sample (void)
 LinToulaw_Sample.
static int load_module (void)
static int reload (void)
static int ulawtolin_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
 convert and store samples in outbuf
static struct ast_frameulawtolin_sample (void)
 ulawToLin_Sample
static int unload_module (void)

Variables

static struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT | AST_MODFLAG_BUILDSUM, .description = "mu-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 = "361d7bb937402d51e4658efb5b4d76e4" , .load = load_module, .unload = unload_module, .reload = reload, }
static const struct ast_module_infoast_module_info = &__mod_info
static struct ast_translator lintoulaw
 The complete translator for LinToulaw.
static struct ast_translator ulawtolin
 The complete translator for ulawToLin.


Detailed Description

codec_ulaw.c - translate between signed linear and ulaw

Definition in file codec_ulaw.c.


Define Documentation

#define BUFFER_SAMPLES   8096

Definition at line 47 of file codec_ulaw.c.


Function Documentation

static void __reg_module ( void   )  [static]

Definition at line 181 of file codec_ulaw.c.

static void __unreg_module ( void   )  [static]

Definition at line 181 of file codec_ulaw.c.

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

convert and store samples in outbuf

Definition at line 72 of file codec_ulaw.c.

References AST_LIN2MU, ast_trans_pvt::datalen, f, ast_trans_pvt::outbuf, and ast_trans_pvt::samples.

00073 {
00074    int i = f->samples;
00075    char *dst = pvt->outbuf + pvt->samples;
00076    int16_t *src = f->data;
00077 
00078    pvt->samples += i;
00079    pvt->datalen += i;   /* 1 byte/sample */
00080 
00081    while (i--)
00082       *dst++ = AST_LIN2MU(*src++);
00083 
00084    return 0;
00085 }

static struct ast_frame* lintoulaw_sample ( void   )  [static]

LinToulaw_Sample.

Definition at line 106 of file codec_ulaw.c.

References AST_FORMAT_SLINEAR, AST_FRAME_VOICE, f, and slin_ulaw_ex.

00107 {
00108    static struct ast_frame f;
00109    f.frametype = AST_FRAME_VOICE;
00110    f.subclass = AST_FORMAT_SLINEAR;
00111    f.datalen = sizeof(slin_ulaw_ex);
00112    /* Assume 8000 Hz */
00113    f.samples = sizeof(slin_ulaw_ex) / 2;
00114    f.mallocd = 0;
00115    f.offset = 0;
00116    f.src = __PRETTY_FUNCTION__;
00117    f.data = slin_ulaw_ex;
00118    return &f;
00119 }

static int load_module ( void   )  [static]

Definition at line 164 of file codec_ulaw.c.

References ast_register_translator, ast_unregister_translator(), lintoulaw, and ulawtolin.

00165 {
00166    int res;
00167 
00168    res = ast_register_translator(&ulawtolin);
00169    if (!res)
00170       res = ast_register_translator(&lintoulaw);
00171    else
00172       ast_unregister_translator(&ulawtolin);
00173 
00174    return res;
00175 }

static int reload ( void   )  [static]

Definition at line 149 of file codec_ulaw.c.

00150 {
00151    return 0;
00152 }

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

convert and store samples in outbuf

Definition at line 55 of file codec_ulaw.c.

References AST_MULAW, ast_trans_pvt::datalen, f, ast_trans_pvt::outbuf, and ast_trans_pvt::samples.

00056 {
00057    int i = f->samples;
00058    unsigned char *src = f->data;
00059    int16_t *dst = (int16_t *)pvt->outbuf + pvt->samples;
00060 
00061    pvt->samples += i;
00062    pvt->datalen += i * 2;  /* 2 bytes/sample */
00063 
00064    /* convert and copy in outbuf */
00065    while (i--)
00066       *dst++ = AST_MULAW(*src++);
00067 
00068    return 0;
00069 }

static struct ast_frame* ulawtolin_sample ( void   )  [static]

ulawToLin_Sample

*

Definition at line 88 of file codec_ulaw.c.

References AST_FORMAT_ULAW, AST_FRAME_VOICE, f, and ulaw_slin_ex.

00089 {
00090    static struct ast_frame f;
00091    f.frametype = AST_FRAME_VOICE;
00092    f.subclass = AST_FORMAT_ULAW;
00093    f.datalen = sizeof(ulaw_slin_ex);
00094    f.samples = sizeof(ulaw_slin_ex);
00095    f.mallocd = 0;
00096    f.offset = 0;
00097    f.src = __PRETTY_FUNCTION__;
00098    f.data = ulaw_slin_ex;
00099    return &f;
00100 }

static int unload_module ( void   )  [static]

Definition at line 154 of file codec_ulaw.c.

References ast_unregister_translator(), lintoulaw, and ulawtolin.

00155 {
00156    int res;
00157 
00158    res = ast_unregister_translator(&lintoulaw);
00159    res |= ast_unregister_translator(&ulawtolin);
00160 
00161    return res;
00162 }


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT | AST_MODFLAG_BUILDSUM, .description = "mu-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 = "361d7bb937402d51e4658efb5b4d76e4" , .load = load_module, .unload = unload_module, .reload = reload, } [static]

Definition at line 181 of file codec_ulaw.c.

const struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 181 of file codec_ulaw.c.

struct ast_translator lintoulaw [static]

The complete translator for LinToulaw.

Definition at line 139 of file codec_ulaw.c.

Referenced by dahdi_encoder_framein(), load_module(), and unload_module().

struct ast_translator ulawtolin [static]

The complete translator for ulawToLin.

Definition at line 125 of file codec_ulaw.c.

Referenced by dahdi_decoder_frameout(), load_module(), and unload_module().


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