Fri Nov 12 11:58:29 2010

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 "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 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 = "0901e4e500243c855563a2d78b0c03e4" , .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 151 of file codec_alaw.c.

static void __unreg_module ( void   )  [static]

Definition at line 151 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 43 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.

00044 {
00045    int i = f->samples;
00046    unsigned char *src = f->data.ptr;
00047    int16_t *dst = pvt->outbuf.i16 + pvt->samples;
00048 
00049    pvt->samples += i;
00050    pvt->datalen += i * 2;  /* 2 bytes/sample */
00051    
00052    while (i--)
00053       *dst++ = AST_ALAW(*src++);
00054 
00055    return 0;
00056 }

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 59 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.

00060 {
00061    int i = f->samples;
00062    char *dst = pvt->outbuf.c + pvt->samples;
00063    int16_t *src = f->data.ptr;
00064 
00065    pvt->samples += i;
00066    pvt->datalen += i;   /* 1 byte/sample */
00067 
00068    while (i--) 
00069       *dst++ = AST_LIN2A(*src++);
00070 
00071    return 0;
00072 }

static int load_module ( void   )  [static]

Definition at line 131 of file codec_alaw.c.

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

00132 {
00133    int res;
00134 
00135    if (parse_config(0))
00136       return AST_MODULE_LOAD_DECLINE;
00137    res = ast_register_translator(&alawtolin);
00138    if (!res)
00139       res = ast_register_translator(&lintoalaw);
00140    else
00141       ast_unregister_translator(&alawtolin);
00142    if (res)
00143       return AST_MODULE_LOAD_FAILURE;
00144    return AST_MODULE_LOAD_SUCCESS;
00145 }

static int parse_config ( int  reload  )  [static]

Definition at line 95 of file codec_alaw.c.

References ast_config_destroy(), ast_config_load, ast_true(), ast_variable_browse(), ast_verb, CONFIG_FLAG_FILEUNCHANGED, CONFIG_STATUS_FILEINVALID, CONFIG_STATUS_FILEMISSING, CONFIG_STATUS_FILEUNCHANGED, ast_variable::name, ast_variable::next, ast_translator::useplc, ast_variable::value, and var.

Referenced by load_module(), and reload().

00096 {
00097    struct ast_variable *var;
00098    struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
00099    struct ast_config *cfg = ast_config_load("codecs.conf", config_flags);
00100    if (cfg == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEUNCHANGED || cfg == CONFIG_STATUS_FILEINVALID)
00101       return 0;
00102    for (var = ast_variable_browse(cfg, "plc"); var; var = var->next) {
00103       if (!strcasecmp(var->name, "genericplc")) {
00104          alawtolin.useplc = ast_true(var->value) ? 1 : 0;
00105          ast_verb(3, "codec_alaw: %susing generic PLC\n", alawtolin.useplc ? "" : "not ");
00106       }
00107    }
00108    ast_config_destroy(cfg);
00109    return 0;
00110 }

static int reload ( void   )  [static]

standard module stuff

Definition at line 114 of file codec_alaw.c.

References AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, and parse_config().

00115 {
00116    if (parse_config(1))
00117       return AST_MODULE_LOAD_DECLINE;
00118    return AST_MODULE_LOAD_SUCCESS;
00119 }

static int unload_module ( void   )  [static]

Definition at line 121 of file codec_alaw.c.

References ast_unregister_translator().

00122 {
00123    int res;
00124 
00125    res = ast_unregister_translator(&lintoalaw);
00126    res |= ast_unregister_translator(&alawtolin);
00127 
00128    return res;
00129 }


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 = "0901e4e500243c855563a2d78b0c03e4" , .load = load_module, .unload = unload_module, .reload = reload, } [static]

Definition at line 151 of file codec_alaw.c.

struct ast_translator alawtolin [static]

Definition at line 74 of file codec_alaw.c.

Definition at line 151 of file codec_alaw.c.

struct ast_translator lintoalaw [static]

Definition at line 85 of file codec_alaw.c.


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