Wed Oct 28 11:46:07 2009

Asterisk developer's documentation


codec_ilbc.c File Reference

Translate between signed linear and Internet Low Bitrate Codec. More...

#include "asterisk.h"
#include "asterisk/translate.h"
#include "asterisk/module.h"
#include "asterisk/utils.h"
#include "ilbc/iLBC_encode.h"
#include "ilbc/iLBC_decode.h"
#include "slin_ilbc_ex.h"
#include "ilbc_slin_ex.h"

Include dependency graph for codec_ilbc.c:

Go to the source code of this file.

Data Structures

struct  ilbc_coder_pvt

Defines

#define BUFFER_SAMPLES   8000
#define ILBC_FRAME_LEN   50
#define ILBC_MS   30
#define ILBC_SAMPLES   240
#define USE_ILBC_ENHANCER   0

Functions

static void __reg_module (void)
static void __unreg_module (void)
static int ilbctolin_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
 decode a frame and store in outbuf
static int ilbctolin_new (struct ast_trans_pvt *pvt)
static struct ast_frameilbctolin_sample (void)
static int lintoilbc_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
 store a frame into a temporary buffer, for later decoding
static struct ast_framelintoilbc_frameout (struct ast_trans_pvt *pvt)
 encode the temporary buffer and generate a frame
static int lintoilbc_new (struct ast_trans_pvt *pvt)
static struct ast_framelintoilbc_sample (void)
static int load_module (void)
static int unload_module (void)

Variables

static struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "iLBC 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 const struct
ast_module_info
ast_module_info = &__mod_info
static struct ast_translator ilbctolin
static struct ast_translator lintoilbc


Detailed Description

Translate between signed linear and Internet Low Bitrate Codec.

Definition in file codec_ilbc.c.


Define Documentation

#define BUFFER_SAMPLES   8000

Definition at line 53 of file codec_ilbc.c.

#define ILBC_FRAME_LEN   50

Definition at line 51 of file codec_ilbc.c.

Referenced by ilbctolin_framein(), and lintoilbc_frameout().

#define ILBC_MS   30

Definition at line 48 of file codec_ilbc.c.

Referenced by ilbctolin_new(), and lintoilbc_new().

#define ILBC_SAMPLES   240

#define USE_ILBC_ENHANCER   0

Definition at line 47 of file codec_ilbc.c.

Referenced by ilbctolin_new().


Function Documentation

static void __reg_module ( void   )  [static]

Definition at line 239 of file codec_ilbc.c.

static void __unreg_module ( void   )  [static]

Definition at line 239 of file codec_ilbc.c.

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

decode a frame and store in outbuf

Definition at line 110 of file codec_ilbc.c.

References ast_log(), BUFFER_SAMPLES, ast_frame::data, ast_trans_pvt::datalen, ast_frame::datalen, ilbc_coder_pvt::dec, ILBC_FRAME_LEN, ILBC_SAMPLES, LOG_WARNING, ast_trans_pvt::outbuf, ast_trans_pvt::pvt, ast_trans_pvt::samples, ast_frame::samples, and ast_frame::src.

00111 {
00112    struct ilbc_coder_pvt *tmp = pvt->pvt;
00113    int plc_mode = 1; /* 1 = normal data, 0 = plc */
00114    /* Assuming there's space left, decode into the current buffer at
00115       the tail location.  Read in as many frames as there are */
00116    int x,i;
00117    int16_t *dst = (int16_t *)pvt->outbuf;
00118    float tmpf[ILBC_SAMPLES];
00119 
00120    if (f->datalen == 0) { /* native PLC, set fake f->datalen and clear plc_mode */
00121       f->datalen = ILBC_FRAME_LEN;
00122       f->samples = ILBC_SAMPLES;
00123       plc_mode = 0;  /* do native plc */
00124       pvt->samples += ILBC_SAMPLES;
00125    }
00126 
00127    if (f->datalen % ILBC_FRAME_LEN) {
00128       ast_log(LOG_WARNING, "Huh?  An ilbc frame that isn't a multiple of 50 bytes long from %s (%d)?\n", f->src, f->datalen);
00129       return -1;
00130    }
00131    
00132    for (x=0; x < f->datalen ; x += ILBC_FRAME_LEN) {
00133       if (pvt->samples + ILBC_SAMPLES > BUFFER_SAMPLES) {   
00134          ast_log(LOG_WARNING, "Out of buffer space\n");
00135          return -1;
00136       }     
00137       iLBC_decode(tmpf, plc_mode ? f->data + x : NULL, &tmp->dec, plc_mode);
00138       for ( i=0; i < ILBC_SAMPLES; i++)
00139          dst[pvt->samples + i] = tmpf[i];
00140       pvt->samples += ILBC_SAMPLES;
00141       pvt->datalen += 2*ILBC_SAMPLES;
00142    }
00143    return 0;
00144 }

static int ilbctolin_new ( struct ast_trans_pvt pvt  )  [static]

Definition at line 71 of file codec_ilbc.c.

References ilbc_coder_pvt::dec, ILBC_MS, ast_trans_pvt::pvt, and USE_ILBC_ENHANCER.

00072 {
00073    struct ilbc_coder_pvt *tmp = pvt->pvt;
00074 
00075    initDecode(&tmp->dec, ILBC_MS, USE_ILBC_ENHANCER);
00076 
00077    return 0;
00078 }

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

Definition at line 94 of file codec_ilbc.c.

References AST_FORMAT_ILBC, AST_FRAME_VOICE, ast_frame::data, ast_frame::datalen, ast_frame::frametype, ILBC_SAMPLES, ilbc_slin_ex, ast_frame::mallocd, ast_frame::offset, ast_frame::samples, ast_frame::src, and ast_frame::subclass.

00095 {
00096    static struct ast_frame f;
00097    f.frametype = AST_FRAME_VOICE;
00098    f.subclass = AST_FORMAT_ILBC;
00099    f.datalen = sizeof(ilbc_slin_ex);
00100    /* All frames are 30 ms long */
00101    f.samples = ILBC_SAMPLES;
00102    f.mallocd = 0;
00103    f.offset = 0;
00104    f.src = __PRETTY_FUNCTION__;
00105    f.data = ilbc_slin_ex;
00106    return &f;
00107 }

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

store a frame into a temporary buffer, for later decoding

Definition at line 147 of file codec_ilbc.c.

References ilbc_coder_pvt::buf, ast_frame::data, ast_frame::datalen, ast_trans_pvt::pvt, ast_frame::samples, and ast_trans_pvt::samples.

00148 {
00149    struct ilbc_coder_pvt *tmp = pvt->pvt;
00150 
00151    /* Just add the frames to our stream */
00152    /* XXX We should look at how old the rest of our stream is, and if it
00153       is too old, then we should overwrite it entirely, otherwise we can
00154       get artifacts of earlier talk that do not belong */
00155    memcpy(tmp->buf + pvt->samples, f->data, f->datalen);
00156    pvt->samples += f->samples;
00157    return 0;
00158 }

static struct ast_frame* lintoilbc_frameout ( struct ast_trans_pvt pvt  )  [static, read]

encode the temporary buffer and generate a frame

Definition at line 161 of file codec_ilbc.c.

References ast_trans_frameout(), ilbc_coder_pvt::buf, ilbc_coder_pvt::enc, ILBC_FRAME_LEN, ILBC_SAMPLES, ast_trans_pvt::outbuf, ast_trans_pvt::pvt, and ast_trans_pvt::samples.

00162 {
00163    struct ilbc_coder_pvt *tmp = pvt->pvt;
00164    int datalen = 0;
00165    int samples = 0;
00166 
00167    /* We can't work on anything less than a frame in size */
00168    if (pvt->samples < ILBC_SAMPLES)
00169       return NULL;
00170    while (pvt->samples >= ILBC_SAMPLES) {
00171       float tmpf[ILBC_SAMPLES];
00172       int i;
00173 
00174       /* Encode a frame of data */
00175       for (i = 0 ; i < ILBC_SAMPLES ; i++)
00176          tmpf[i] = tmp->buf[samples + i];
00177       iLBC_encode((unsigned char *) pvt->outbuf + datalen, tmpf, &tmp->enc);
00178 
00179       datalen += ILBC_FRAME_LEN;
00180       samples += ILBC_SAMPLES;
00181       pvt->samples -= ILBC_SAMPLES;
00182    }
00183 
00184    /* Move the data at the end of the buffer to the front */
00185    if (pvt->samples)
00186       memmove(tmp->buf, tmp->buf + samples, pvt->samples * 2);
00187 
00188    return ast_trans_frameout(pvt, datalen, samples);
00189 }

static int lintoilbc_new ( struct ast_trans_pvt pvt  )  [static]

Definition at line 62 of file codec_ilbc.c.

References ilbc_coder_pvt::enc, ILBC_MS, and ast_trans_pvt::pvt.

00063 {
00064    struct ilbc_coder_pvt *tmp = pvt->pvt;
00065 
00066    initEncode(&tmp->enc, ILBC_MS);
00067 
00068    return 0;
00069 }

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

Definition at line 80 of file codec_ilbc.c.

References AST_FORMAT_SLINEAR, AST_FRAME_VOICE, ast_frame::data, ast_frame::datalen, ast_frame::frametype, ast_frame::mallocd, ast_frame::offset, ast_frame::samples, slin_ilbc_ex, ast_frame::src, and ast_frame::subclass.

00081 {
00082    static struct ast_frame f;
00083    f.frametype = AST_FRAME_VOICE;
00084    f.subclass = AST_FORMAT_SLINEAR;
00085    f.datalen = sizeof(slin_ilbc_ex);
00086    f.samples = sizeof(slin_ilbc_ex)/2;
00087    f.mallocd = 0;
00088    f.offset = 0;
00089    f.src = __PRETTY_FUNCTION__;
00090    f.data = slin_ilbc_ex;
00091    return &f;
00092 }

static int load_module ( void   )  [static]

Definition at line 225 of file codec_ilbc.c.

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

00226 {
00227    int res;
00228 
00229    res = ast_register_translator(&ilbctolin);
00230    if (!res) 
00231       res=ast_register_translator(&lintoilbc);
00232    else
00233       ast_unregister_translator(&ilbctolin);
00234    if (res)
00235       return AST_MODULE_LOAD_FAILURE;
00236    return AST_MODULE_LOAD_SUCCESS;
00237 }

static int unload_module ( void   )  [static]

Definition at line 215 of file codec_ilbc.c.

References ast_unregister_translator().

00216 {
00217    int res;
00218 
00219    res = ast_unregister_translator(&lintoilbc);
00220    res |= ast_unregister_translator(&ilbctolin);
00221 
00222    return res;
00223 }


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "iLBC 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 239 of file codec_ilbc.c.

const struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 239 of file codec_ilbc.c.

struct ast_translator ilbctolin [static]

Definition at line 191 of file codec_ilbc.c.

struct ast_translator lintoilbc [static]

Definition at line 203 of file codec_ilbc.c.


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