Fri Jun 19 12:10:30 2009

Asterisk developer's documentation


codec_alaw.c File Reference

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 "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 alawtolin_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
 decode frame into lin and fill output buffer.
static struct ast_framealawtolin_sample (void)
 alawToLin_Sample
static int lintoalaw_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
 convert and store input samples in output buffer
static struct ast_framelintoalaw_sample (void)
 LinToalaw_Sample.
static int load_module (void)
static int parse_config (int reload)
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 = "a9c98e5d177805051735cb5b0b16b0a0" , .load = load_module, .unload = unload_module, .reload = reload, }
static struct ast_translator alawtolin
static struct ast_module_infoast_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 36 of file codec_alaw.c.


Function Documentation

static void __reg_module ( void   )  [static]

Definition at line 184 of file codec_alaw.c.

static void __unreg_module ( void   )  [static]

Definition at line 184 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 44 of file codec_alaw.c.

References AST_ALAW, ast_trans_pvt::datalen, f, ast_trans_pvt::i16, ast_trans_pvt::outbuf, and ast_trans_pvt::samples.

00045 {
00046    int i = f->samples;
00047    unsigned char *src = f->data.ptr;
00048    int16_t *dst = pvt->outbuf.i16 + pvt->samples;
00049 
00050    pvt->samples += i;
00051    pvt->datalen += i * 2;  /* 2 bytes/sample */
00052    
00053    while (i--)
00054       *dst++ = AST_ALAW(*src++);
00055 
00056    return 0;
00057 }

static struct ast_frame* alawtolin_sample ( void   )  [static]

alawToLin_Sample

Definition at line 76 of file codec_alaw.c.

References AST_FORMAT_ALAW, AST_FRAME_VOICE, f, and ulaw_slin_ex.

00077 {
00078    static struct ast_frame f;
00079    f.frametype = AST_FRAME_VOICE;
00080    f.subclass = AST_FORMAT_ALAW;
00081    f.datalen = sizeof(ulaw_slin_ex);
00082    f.samples = sizeof(ulaw_slin_ex);
00083    f.mallocd = 0;
00084    f.offset = 0;
00085    f.src = __PRETTY_FUNCTION__;
00086    f.data.ptr = ulaw_slin_ex;
00087    return &f;
00088 }

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 60 of file codec_alaw.c.

References AST_LIN2A, ast_trans_pvt::c, ast_trans_pvt::datalen, f, ast_trans_pvt::outbuf, and ast_trans_pvt::samples.

00061 {
00062    int i = f->samples;
00063    char *dst = pvt->outbuf.c + pvt->samples;
00064    int16_t *src = f->data.ptr;
00065 
00066    pvt->samples += i;
00067    pvt->datalen += i;   /* 1 byte/sample */
00068 
00069    while (i--) 
00070       *dst++ = AST_LIN2A(*src++);
00071 
00072    return 0;
00073 }

static struct ast_frame* lintoalaw_sample ( void   )  [static]

LinToalaw_Sample.

Definition at line 91 of file codec_alaw.c.

References AST_FORMAT_SLINEAR, AST_FRAME_VOICE, f, and slin_ulaw_ex.

00092 {
00093    static struct ast_frame f;
00094    f.frametype = AST_FRAME_VOICE;
00095    f.subclass = AST_FORMAT_SLINEAR;
00096    f.datalen = sizeof(slin_ulaw_ex);
00097    f.samples = sizeof(slin_ulaw_ex) / 2;
00098    f.mallocd = 0;
00099    f.offset = 0;
00100    f.src = __PRETTY_FUNCTION__;
00101    f.data.ptr = slin_ulaw_ex;
00102    return &f;
00103 }

static int load_module ( void   )  [static]

Definition at line 164 of file codec_alaw.c.

References alawtolin, AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_SUCCESS, ast_register_translator, ast_unregister_translator(), lintoalaw, and parse_config().

00165 {
00166    int res;
00167 
00168    if (parse_config(0))
00169       return AST_MODULE_LOAD_DECLINE;
00170    res = ast_register_translator(&alawtolin);
00171    if (!res)
00172       res = ast_register_translator(&lintoalaw);
00173    else
00174       ast_unregister_translator(&alawtolin);
00175    if (res)
00176       return AST_MODULE_LOAD_FAILURE;
00177    return AST_MODULE_LOAD_SUCCESS;
00178 }

static int parse_config ( int  reload  )  [static]

Definition at line 126 of file codec_alaw.c.

References alawtolin, ast_config_load, ast_true(), ast_variable_browse(), ast_verb, CONFIG_FLAG_FILEUNCHANGED, config_flags, CONFIG_STATUS_FILEUNCHANGED, ast_translator::useplc, and var.

00127 {
00128    struct ast_variable *var;
00129    struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
00130    struct ast_config *cfg = ast_config_load("codecs.conf", config_flags);
00131    if (cfg == NULL)
00132       return 0;
00133    if (cfg == CONFIG_STATUS_FILEUNCHANGED)
00134       return 0;
00135    for (var = ast_variable_browse(cfg, "plc"); var; var = var->next) {
00136       if (!strcasecmp(var->name, "genericplc")) {
00137          alawtolin.useplc = ast_true(var->value) ? 1 : 0;
00138          ast_verb(3, "codec_alaw: %susing generic PLC\n", alawtolin.useplc ? "" : "not ");
00139       }
00140    }
00141    ast_config_destroy(cfg);
00142    return 0;
00143 }

static int reload ( void   )  [static]

standard module stuff

Definition at line 147 of file codec_alaw.c.

References AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, and parse_config().

00148 {
00149    if (parse_config(1))
00150       return AST_MODULE_LOAD_DECLINE;
00151    return AST_MODULE_LOAD_SUCCESS;
00152 }

static int unload_module ( void   )  [static]

Definition at line 154 of file codec_alaw.c.

References alawtolin, ast_unregister_translator(), and lintoalaw.

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


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 = "a9c98e5d177805051735cb5b0b16b0a0" , .load = load_module, .unload = unload_module, .reload = reload, } [static]

Definition at line 184 of file codec_alaw.c.

struct ast_translator alawtolin [static]

Definition at line 105 of file codec_alaw.c.

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

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 184 of file codec_alaw.c.

struct ast_translator lintoalaw [static]

Definition at line 116 of file codec_alaw.c.

Referenced by load_module(), and unload_module().


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