codec_lpc10.c File Reference

Translate between signed linear and LPC10 (Linear Predictor Code). More...

#include "asterisk.h"
#include "asterisk/translate.h"
#include "asterisk/config.h"
#include "asterisk/module.h"
#include "asterisk/utils.h"
#include "lpc10/lpc10.h"
#include "asterisk/slin.h"
#include "ex_lpc10.h"

Include dependency graph for codec_lpc10.c:

Go to the source code of this file.

Data Structures
struct	lpc10_coder_pvt
Defines
#define	BUFFER_SAMPLES 8000
#define	LPC10_BYTES_IN_COMPRESSED_FRAME (LPC10_BITS_IN_COMPRESSED_FRAME + 7)/8
Functions
static void	__reg_module (void)
static void	__unreg_module (void)
static void	build_bits (unsigned char c, INT32 bits)
static void	extract_bits (INT32 bits, unsigned char c)
static int	lintolpc10_framein (struct ast_trans_pvt pvt, struct ast_frame f)
static struct ast_frame *	lintolpc10_frameout (struct ast_trans_pvt *pvt)
static int	load_module (void)
static int	lpc10_dec_new (struct ast_trans_pvt *pvt)
static void	lpc10_destroy (struct ast_trans_pvt *arg)
static int	lpc10_enc_new (struct ast_trans_pvt *pvt)
static int	lpc10tolin_framein (struct ast_trans_pvt pvt, struct ast_frame f)
static int	parse_config (int reload)
static int	reload (void)
static int	unload_module (void)
Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "LPC10 2.4kbps 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_module_info *	ast_module_info = &__mod_info
static struct ast_translator	lintolpc10
static struct ast_translator	lpc10tolin

Detailed Description

Translate between signed linear and LPC10 (Linear Predictor Code).

Definition in file codec_lpc10.c.

Define Documentation

#define BUFFER_SAMPLES 8000

Definition at line 52 of file codec_lpc10.c.

#define LPC10_BYTES_IN_COMPRESSED_FRAME (LPC10_BITS_IN_COMPRESSED_FRAME + 7)/8

Definition at line 50 of file codec_lpc10.c.

Referenced by lintolpc10_frameout(), and lpc10tolin_framein().

Function Documentation

static void __reg_module ( void ) [static]

Definition at line 278 of file codec_lpc10.c.

static void __unreg_module ( void ) [static]

Definition at line 278 of file codec_lpc10.c.

static void build_bits	(	unsigned char *	c,
		INT32 *	bits
	)			`[static]`

Definition at line 92 of file codec_lpc10.c.

Referenced by lintolpc10_frameout().

00093 {
00094    unsigned char mask=0x80;
00095    int x;
00096    *c = 0;
00097    for (x=0;x<LPC10_BITS_IN_COMPRESSED_FRAME;x++) {
00098       if (bits[x])
00099          *c |= mask;
00100       mask = mask >> 1;
00101       if ((x % 8)==7) {
00102          c++;
00103          *c = 0;
00104          mask = 0x80;
00105       }
00106    }
00107 }

static void extract_bits	(	INT32 *	bits,
		unsigned char *	c
	)			`[static]`

Definition at line 78 of file codec_lpc10.c.

Referenced by lpc10tolin_framein().

00079 {
00080    int x;
00081    for (x=0;x<LPC10_BITS_IN_COMPRESSED_FRAME;x++) {
00082       if (*c & (0x80 >> (x & 7)))
00083          bits[x] = 1;
00084       else
00085          bits[x] = 0;
00086       if ((x & 7) == 7)
00087          c++;
00088    }
00089 }

static int lintolpc10_framein	(	struct ast_trans_pvt *	pvt,
		struct ast_frame *	f
	)			`[static]`

Definition at line 142 of file codec_lpc10.c.

References ast_log(), lpc10_coder_pvt::buf, BUFFER_SAMPLES, ast_frame::data, ast_frame::datalen, LOG_WARNING, ast_frame::ptr, ast_trans_pvt::pvt, ast_frame::samples, and ast_trans_pvt::samples.

00143 {
00144    struct lpc10_coder_pvt *tmp = pvt->pvt;
00145 
00146    /* Just add the frames to our stream */
00147    if (pvt->samples + f->samples > BUFFER_SAMPLES) {
00148       ast_log(LOG_WARNING, "Out of buffer space\n");
00149       return -1;
00150    }
00151    memcpy(tmp->buf + pvt->samples, f->data.ptr, f->datalen);
00152    pvt->samples += f->samples;
00153    return 0;
00154 }

static struct ast_frame* lintolpc10_frameout ( struct ast_trans_pvt * pvt ) [static, read]

Definition at line 156 of file codec_lpc10.c.

References ast_trans_frameout(), lpc10_coder_pvt::buf, build_bits(), lpc10_coder_pvt::enc, lpc10_coder_pvt::longer, lpc10_coder_pvt::lpc10, LPC10_BYTES_IN_COMPRESSED_FRAME, ast_trans_pvt::outbuf, ast_trans_pvt::pvt, ast_trans_pvt::samples, and ast_trans_pvt::uc.

00158 00159 00160 00161 00162 00163 00164 00165 00166 00167 00168 00169 00170 00171 00172 00173 00174 00175 00176 00177 00178 00179    } 00180 00181 00182 00183 00184 }

class="fragment">00157 { struct lpc10_coder_pvt *tmp = pvt->pvt; int x; int datalen = 0; /* output frame */ int samples = 0; /* output samples */ float tmpbuf[LPC10_SAMPLES_PER_FRAME]; INT32 bits[LPC10_BITS_IN_COMPRESSED_FRAME]; /* XXX what ??? */ /* We can't work on anything less than a frame in size */ if (pvt->samples < LPC10_SAMPLES_PER_FRAME) return NULL; while (pvt->samples >= LPC10_SAMPLES_PER_FRAME) { /* Encode a frame of data */ for (x=0;x<LPC10_SAMPLES_PER_FRAME;x++) tmpbuf[x] = (float)tmp->buf[x + samples] / 32768.0; lpc10_encode(tmpbuf, bits, tmp->lpc10.enc); build_bits(pvt->outbuf.uc + datalen, bits); datalen += LPC10_BYTES_IN_COMPRESSED_FRAME; samples += LPC10_SAMPLES_PER_FRAME; pvt->samples -= LPC10_SAMPLES_PER_FRAME; /* Use one of the two left over bits to record if this is a 22 or 23 ms frame... important for IAX use */ tmp->longer = 1 - tmp->longer; /* Move the data at the end of the buffer to the front */ if (pvt->samples) memmove(tmp->buf, tmp->buf + samples, pvt->samples * 2); return ast_trans_frameout(pvt, datalen, samples);

static int load_module ( void ) [static]

Definition at line 258 of file codec_lpc10.c.

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

00259 {
00260    int res;
00261 
00262    if (parse_config(0))
00263       return AST_MODULE_LOAD_DECLINE;
00264    res = ast_register_translator(&lpc10tolin);
00265    if (!res) 
00266       res = ast_register_translator(&lintolpc10);
00267    else
00268       ast_unregister_translator(&lpc10tolin);
00269    if (res)
00270       return AST_MODULE_LOAD_FAILURE;
00271    return AST_MODULE_LOAD_SUCCESS;
00272 }

static int lpc10_dec_new ( struct ast_trans_pvt * pvt ) [static]

Definition at line 71 of file codec_lpc10.c.

References lpc10_coder_pvt::dec, lpc10_coder_pvt::lpc10, and ast_trans_pvt::pvt.

00072 {
00073    struct lpc10_coder_pvt *tmp = pvt->pvt;
00074 
00075    return (tmp->lpc10.dec = create_lpc10_decoder_state()) ? 0 : -1;
00076 }

static void lpc10_destroy ( struct ast_trans_pvt * arg ) [static]

Definition at line 187 of file codec_lpc10.c.

References ast_free, lpc10_coder_pvt::enc, lpc10_coder_pvt::lpc10, and ast_trans_pvt::pvt.

00188 {
00189    struct lpc10_coder_pvt *pvt = arg->pvt;
00190    /* Enc and DEC are both just allocated, so they can be freed */
00191    ast_free(pvt->lpc10.enc);
00192 }

static int lpc10_enc_new ( struct ast_trans_pvt * pvt ) [static]

Definition at line 64 of file codec_lpc10.c.

References lpc10_coder_pvt::enc, lpc10_coder_pvt::lpc10, and ast_trans_pvt::pvt.

00065 {
00066    struct lpc10_coder_pvt *tmp = pvt->pvt;
00067 
00068    return (tmp->lpc10.enc = create_lpc10_encoder_state()) ? 0 : -1;
00069 }

static int lpc10tolin_framein	(	struct ast_trans_pvt *	pvt,
		struct ast_frame *	f
	)			`[static]`

Definition at line 109 of file codec_lpc10.c.

References ast_log(), BUFFER_SAMPLES, ast_frame::data, ast_frame::datalen, ast_trans_pvt::datalen, lpc10_coder_pvt::dec, extract_bits(), ast_trans_pvt::i16, len(), LOG_WARNING, lpc10_coder_pvt::lpc10, LPC10_BYTES_IN_COMPRESSED_FRAME, ast_trans_pvt::outbuf, ast_frame::ptr, ast_trans_pvt::pvt, and ast_trans_pvt::samples.

00110 {
00111    struct lpc10_coder_pvt *tmp = pvt->pvt;
00112    int16_t *dst = pvt->outbuf.i16;
00113    int len = 0;
00114 
00115    while (len + LPC10_BYTES_IN_COMPRESSED_FRAME <= f->datalen) {
00116       int x;
00117       float tmpbuf[LPC10_SAMPLES_PER_FRAME];
00118       INT32 bits[LPC10_BITS_IN_COMPRESSED_FRAME]; /* XXX see note */
00119       if (pvt->samples + LPC10_SAMPLES_PER_FRAME > BUFFER_SAMPLES) {
00120          ast_log(LOG_WARNING, "Out of buffer space\n");
00121          return -1;
00122       }
00123       extract_bits(bits, f->data.ptr + len);
00124       if (lpc10_decode(bits, tmpbuf, tmp->lpc10.dec)) {
00125          ast_log(LOG_WARNING, "Invalid lpc10 data\n");
00126          return -1;
00127       }
00128       for (x=0;x<LPC10_SAMPLES_PER_FRAME;x++) {
00129          /* Convert to a short between -1.0 and 1.0 */
00130          dst[pvt->samples + x] = (int16_t)(32768.0 * tmpbuf[x]);
00131       }
00132 
00133       pvt->samples += LPC10_SAMPLES_PER_FRAME;
00134       pvt->datalen += 2*LPC10_SAMPLES_PER_FRAME;
00135       len += LPC10_BYTES_IN_COMPRESSED_FRAME;
00136    }
00137    if (len != f->datalen) 
00138       printf("Decoded %d, expected %d\n", len, f->datalen);
00139    return 0;
00140 }

static int parse_config ( int reload ) [static]

Definition at line 222 of file codec_lpc10.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().

00223 {
00224    struct ast_variable *var;
00225    struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
00226    struct ast_config *cfg = ast_config_load("codecs.conf", config_flags);
00227    if (cfg == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEUNCHANGED || cfg == CONFIG_STATUS_FILEINVALID)
00228       return 0;
00229    for (var = ast_variable_browse(cfg, "plc"); var; var = var->next) {
00230       if (!strcasecmp(var->name, "genericplc")) {
00231          lpc10tolin.useplc = ast_true(var->value) ? 1 : 0;
00232          ast_verb(3, "codec_lpc10: %susing generic PLC\n",
00233                lpc10tolin.useplc ? "" : "not ");
00234       }
00235    }
00236    ast_config_destroy(cfg);
00237    return 0;
00238 }

static int reload ( void ) [static]

Definition at line 240 of file codec_lpc10.c.

References AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, and parse_config().

00241 {
00242    if (parse_config(1))
00243       return AST_MODULE_LOAD_DECLINE;
00244    return AST_MODULE_LOAD_SUCCESS;
00245 }

static int unload_module ( void ) [static]

Definition at line 248 of file codec_lpc10.c.

References ast_unregister_translator().

00249 {
00250    int res;
00251 
00252    res = ast_unregister_translator(&lintolpc10);
00253    res |= ast_unregister_translator(&lpc10tolin);
00254 
00255    return res;
00256 }

Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "LPC10 2.4kbps 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 278 of file codec_lpc10.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 278 of file codec_lpc10.c.

struct ast_translator lintolpc10 [static]

Definition at line 208 of file codec_lpc10.c.

struct ast_translator lpc10tolin [static]

Definition at line 194 of file codec_lpc10.c.

Asterisk developer's documentation

codec_lpc10.c File Reference

Data Structures

Defines

Functions

Variables

Detailed Description

Define Documentation

Function Documentation

Variable Documentation