codec_a_mu.c File Reference

codec_a_mu.c - translate between alaw and ulaw directly More...

#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/translate.h"
#include "asterisk/alaw.h"
#include "asterisk/ulaw.h"
#include "asterisk/utils.h"
#include "ex_ulaw.h"
#include "ex_alaw.h"

Include dependency graph for codec_a_mu.c:

Go to the source code of this file.

Macros
#define	BUFFER_SAMPLES   8000 /* size for the translation buffers */

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
struct ast_module *	AST_MODULE_SELF_SYM (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 int	unload_module (void)
	standard module glue

Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "A-law and Mulaw direct Coder/Decoder" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_DEFAULT, .support_level = AST_MODULE_SUPPORT_CORE, }
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.

Macro Definition Documentation

BUFFER_SAMPLES

#define BUFFER_SAMPLES   8000 /* size for the translation buffers */

Definition at line 38 of file codec_a_mu.c.

Function Documentation

__reg_module()

static void __reg_module ( void  )

static

Definition at line 150 of file codec_a_mu.c.

__unreg_module()

static void __unreg_module ( void  )

static

Definition at line 150 of file codec_a_mu.c.

alawtoulaw_framein()

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 48 of file codec_a_mu.c.

{
    int x = f->samples;
    unsigned char *src = f->data.ptr;
    unsigned char *dst = pvt->outbuf.uc + pvt->samples;
 
    pvt->samples += x;
    pvt->datalen += x;
 
    while (x--)
        *dst++ = a2mu[*src++];
 
    return 0;
}

References a2mu, ast_frame::data, ast_trans_pvt::datalen, ast_trans_pvt::outbuf, ast_frame::ptr, ast_frame::samples, ast_trans_pvt::samples, and ast_trans_pvt::uc.

AST_MODULE_SELF_SYM()

struct ast_module * AST_MODULE_SELF_SYM

(

void

)

Definition at line 150 of file codec_a_mu.c.

load_module()

static int load_module ( void  )

static

Definition at line 129 of file codec_a_mu.c.

{
    int res;
    int x;
 
    for (x=0;x<256;x++) {
        mu2a[x] = AST_LIN2A(AST_MULAW(x));
        a2mu[x] = AST_LIN2MU(AST_ALAW(x));
    }
 
    res = ast_register_translator(&alawtoulaw);
    res |= ast_register_translator(&ulawtoalaw);
 
    if (res) {
        unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
 
    return AST_MODULE_LOAD_SUCCESS;
}

References a2mu, alawtoulaw, AST_ALAW, AST_LIN2A, AST_LIN2MU, AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, AST_MULAW, ast_register_translator, mu2a, ulawtoalaw, and unload_module().

ulawtoalaw_framein()

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 64 of file codec_a_mu.c.

{
    int x = f->samples;
    unsigned char *src = f->data.ptr;
    unsigned char *dst = pvt->outbuf.uc + pvt->samples;
 
    pvt->samples += x;
    pvt->datalen += x;
 
    while (x--)
        *dst++ = mu2a[*src++];
 
    return 0;
}

References ast_frame::data, ast_trans_pvt::datalen, mu2a, ast_trans_pvt::outbuf, ast_frame::ptr, ast_frame::samples, ast_trans_pvt::samples, and ast_trans_pvt::uc.

unload_module()

static int unload_module ( void  )

static

standard module glue

Definition at line 119 of file codec_a_mu.c.

{
    int res;
 
    res = ast_unregister_translator(&ulawtoalaw);
    res |= ast_unregister_translator(&alawtoulaw);
 
    return res;
}

References alawtoulaw, ast_unregister_translator(), and ulawtoalaw.

Referenced by load_module().

Variable Documentation

__mod_info

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "A-law and Mulaw direct Coder/Decoder" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_DEFAULT, .support_level = AST_MODULE_SUPPORT_CORE, }

static

Definition at line 150 of file codec_a_mu.c.

a2mu

unsigned char a2mu[256]

static

Definition at line 41 of file codec_a_mu.c.

Referenced by alawtoulaw_framein(), and load_module().

alawtoulaw

struct ast_translator alawtoulaw

static

Definition at line 79 of file codec_a_mu.c.

                                          {
    .name = "alawtoulaw",
    .src_codec = {
        .name = "alaw",
        .type = AST_MEDIA_TYPE_AUDIO,
        .sample_rate = 8000,
    },
    .dst_codec = {
        .name = "ulaw",
        .type = AST_MEDIA_TYPE_AUDIO,
        .sample_rate = 8000,
    },
    .format = "ulaw",
    .framein = alawtoulaw_framein,
    .sample = alaw_sample,
    .buffer_samples = BUFFER_SAMPLES,
    .buf_size = BUFFER_SAMPLES,
};

Referenced by load_module(), and unload_module().

ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info

static

Definition at line 150 of file codec_a_mu.c.

mu2a

unsigned char mu2a[256]

static

Definition at line 40 of file codec_a_mu.c.

Referenced by load_module(), and ulawtoalaw_framein().

ulawtoalaw

struct ast_translator ulawtoalaw

static

Definition at line 98 of file codec_a_mu.c.

                                          {
    .name = "ulawtoalaw",
    .src_codec = {
        .name = "ulaw",
        .type = AST_MEDIA_TYPE_AUDIO,
        .sample_rate = 8000,
    },
    .dst_codec = {
        .name = "alaw",
        .type = AST_MEDIA_TYPE_AUDIO,
        .sample_rate = 8000,
    },
    .format = "alaw",
    .framein = ulawtoalaw_framein,
    .sample = ulaw_sample,
    .buffer_samples = BUFFER_SAMPLES,
    .buf_size = BUFFER_SAMPLES,
};

Referenced by load_module(), and unload_module().