Sat Jul 26 06:14:04 2008

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"

Include dependency graph for codec_ulaw.c:

Go to the source code of this file.

Defines

#define BUFFER_SAMPLES   8096

Functions

 AST_MODULE_INFO (ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT,"mu-Law Coder/Decoder",.load=load_module,.unload=unload_module,.reload=reload,)
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 void parse_config (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_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

AST_MODULE_INFO ( ASTERISK_GPL_KEY  ,
AST_MODFLAG_DEFAULT  ,
"mu-Law Coder/Decoder"  ,
load = load_module,
unload = unload_module,
reload = reload 
)

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 183 of file codec_ulaw.c.

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

00184 {
00185    int res;
00186 
00187    parse_config();
00188    res = ast_register_translator(&ulawtolin);
00189    if (!res)
00190       res = ast_register_translator(&lintoulaw);
00191    else
00192       ast_unregister_translator(&ulawtolin);
00193 
00194    return res;
00195 }

static void parse_config ( void   )  [static]

Definition at line 150 of file codec_ulaw.c.

References ast_config_load(), ast_true(), ast_variable_browse(), ast_verbose(), option_verbose, ulawtolin, ast_translator::useplc, var, and VERBOSE_PREFIX_3.

00151 {
00152    struct ast_variable *var;
00153    struct ast_config *cfg = ast_config_load("codecs.conf");
00154    if (!cfg)
00155       return;
00156    for (var = ast_variable_browse(cfg, "plc"); var; var = var->next) {
00157       if (!strcasecmp(var->name, "genericplc")) {
00158          ulawtolin.useplc = ast_true(var->value) ? 1 : 0;
00159          if (option_verbose > 2)
00160             ast_verbose(VERBOSE_PREFIX_3 "codec_ulaw: %susing generic PLC\n", ulawtolin.useplc ? "" : "not ");
00161       }
00162    }
00163    ast_config_destroy(cfg);
00164 }

static int reload ( void   )  [static]

Definition at line 166 of file codec_ulaw.c.

References parse_config().

00167 {
00168    parse_config();
00169 
00170    return 0;
00171 }

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 173 of file codec_ulaw.c.

References ast_unregister_translator(), lintoulaw, and ulawtolin.

00174 {
00175    int res;
00176 
00177    res = ast_unregister_translator(&lintoulaw);
00178    res |= ast_unregister_translator(&ulawtolin);
00179 
00180    return res;
00181 }


Variable Documentation

struct ast_translator lintoulaw [static]

The complete translator for LinToulaw.

Definition at line 140 of file codec_ulaw.c.

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


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