Thu Oct 11 06:43:16 2012

Asterisk developer's documentation


codec_a_mu.c File Reference

codec_a_mu.c - translate between alaw and ulaw directly 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/translate.h"
#include "asterisk/channel.h"
#include "asterisk/alaw.h"
#include "asterisk/ulaw.h"
#include "asterisk/utils.h"
#include "ulaw_slin_ex.h"

Include dependency graph for codec_a_mu.c:

Go to the source code of this file.

Defines

#define BUFFER_SAMPLES   8000

Functions

static void __reg_module (void)
static void __unreg_module (void)
static int alawtoulaw_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
 convert frame data and store into the buffer
static struct ast_framealawtoulaw_sample (void)
static int load_module (void)
static int ulawtoalaw_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
 convert frame data and store into the buffer
static struct ast_frameulawtoalaw_sample (void)
static int unload_module (void)
 standard module glue

Variables

static struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT | AST_MODFLAG_BUILDSUM, .description = "A-law and Mulaw direct 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, }
static unsigned char a2mu [256]
static struct ast_translator alawtoulaw
static const struct
ast_module_info
ast_module_info = &__mod_info
static unsigned char mu2a [256]
static struct ast_translator ulawtoalaw


Detailed Description

codec_a_mu.c - translate between alaw and ulaw directly

Definition in file codec_a_mu.c.


Define Documentation

#define BUFFER_SAMPLES   8000


Function Documentation

static void __reg_module ( void   )  [static]

Definition at line 168 of file codec_a_mu.c.

static void __unreg_module ( void   )  [static]

Definition at line 168 of file codec_a_mu.c.

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

convert frame data and store into the buffer

Definition at line 56 of file codec_a_mu.c.

References ast_frame::data, ast_trans_pvt::datalen, ast_trans_pvt::outbuf, ast_trans_pvt::samples, and ast_frame::samples.

00057 {
00058    int x = f->samples;
00059    unsigned char *src = f->data;
00060    unsigned char *dst = (unsigned char *)pvt->outbuf + pvt->samples;
00061 
00062    pvt->samples += x;
00063    pvt->datalen += x;
00064 
00065    while (x--)
00066       *dst++ = a2mu[*src++];
00067 
00068    return 0;
00069 }

static struct ast_frame* alawtoulaw_sample ( void   )  [static, read]

Definition at line 90 of file codec_a_mu.c.

References AST_FORMAT_ALAW, AST_FRAME_VOICE, ast_frame::data, ast_frame::datalen, ast_frame::frametype, ast_frame::mallocd, ast_frame::offset, ast_frame::samples, ast_frame::src, ast_frame::subclass, and ulaw_slin_ex.

00091 {
00092    static struct ast_frame f;
00093    f.frametype = AST_FRAME_VOICE;
00094    f.subclass = AST_FORMAT_ALAW;
00095    f.datalen = sizeof(ulaw_slin_ex);
00096    f.samples = sizeof(ulaw_slin_ex);
00097    f.mallocd = 0;
00098    f.offset = 0;
00099    f.src = __PRETTY_FUNCTION__;
00100    f.data = ulaw_slin_ex; /* XXX what ? */
00101    return &f;
00102 }

static int load_module ( void   )  [static]

Definition at line 150 of file codec_a_mu.c.

References AST_ALAW, AST_LIN2A, AST_LIN2MU, AST_MULAW, ast_register_translator, and ast_unregister_translator().

00151 {
00152    int res;
00153    int x;
00154 
00155    for (x=0;x<256;x++) {
00156       mu2a[x] = AST_LIN2A(AST_MULAW(x));
00157       a2mu[x] = AST_LIN2MU(AST_ALAW(x));
00158    }
00159    res = ast_register_translator(&alawtoulaw);
00160    if (!res)
00161       res = ast_register_translator(&ulawtoalaw);
00162    else
00163       ast_unregister_translator(&alawtoulaw);
00164 
00165    return res;
00166 }

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

convert frame data and store into the buffer

Definition at line 72 of file codec_a_mu.c.

References ast_frame::data, ast_trans_pvt::datalen, ast_trans_pvt::outbuf, ast_trans_pvt::samples, and ast_frame::samples.

00073 {
00074    int x = f->samples;
00075    unsigned char *src = f->data;
00076    unsigned char *dst = (unsigned char *)pvt->outbuf + pvt->samples;
00077 
00078    pvt->samples += x;
00079    pvt->datalen += x;
00080 
00081    while (x--)
00082       *dst++ = mu2a[*src++];
00083 
00084    return 0;
00085 }

static struct ast_frame* ulawtoalaw_sample ( void   )  [static, read]

Definition at line 104 of file codec_a_mu.c.

References AST_FORMAT_ULAW, AST_FRAME_VOICE, ast_frame::data, ast_frame::datalen, ast_frame::frametype, ast_frame::mallocd, ast_frame::offset, ast_frame::samples, ast_frame::src, ast_frame::subclass, and ulaw_slin_ex.

00105 {
00106    static struct ast_frame f;
00107    f.frametype = AST_FRAME_VOICE;
00108    f.subclass = AST_FORMAT_ULAW;
00109    f.datalen = sizeof(ulaw_slin_ex);
00110    f.samples = sizeof(ulaw_slin_ex);
00111    f.mallocd = 0;
00112    f.offset = 0;
00113    f.src = __PRETTY_FUNCTION__;
00114    f.data = ulaw_slin_ex;
00115    return &f;
00116 }

static int unload_module ( void   )  [static]

standard module glue

Definition at line 140 of file codec_a_mu.c.

References ast_unregister_translator().

00141 {
00142    int res;
00143 
00144    res = ast_unregister_translator(&ulawtoalaw);
00145    res |= ast_unregister_translator(&alawtoulaw);
00146 
00147    return res;
00148 }


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT | AST_MODFLAG_BUILDSUM, .description = "A-law and Mulaw direct 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, } [static]

Definition at line 168 of file codec_a_mu.c.

unsigned char a2mu[256] [static]

Definition at line 49 of file codec_a_mu.c.

struct ast_translator alawtoulaw [static]

Definition at line 118 of file codec_a_mu.c.

const struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 168 of file codec_a_mu.c.

unsigned char mu2a[256] [static]

Definition at line 48 of file codec_a_mu.c.

struct ast_translator ulawtoalaw [static]

Definition at line 128 of file codec_a_mu.c.


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