codec_g726.c - translate between signed linear and ITU G.726-32kbps (both RFC3551 and AAL2 codeword packing) More...
#include "asterisk.h"
#include "asterisk/lock.h"
#include "asterisk/linkedlists.h"
#include "asterisk/module.h"
#include "asterisk/config.h"
#include "asterisk/translate.h"
#include "asterisk/utils.h"
#include "log2comp.h"
#include "asterisk/slin.h"
#include "ex_g726.h"
Go to the source code of this file.
Data Structures | |
struct | g726_coder_pvt |
struct | g726_state |
Defines | |
#define | BUF_SHIFT 5 |
#define | BUFFER_SAMPLES 8096 |
#define | WANT_ASM |
Functions | |
AST_MODULE_INFO (ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT,"ITU G.726-32kbps G726 Transcoder",.load=load_module,.unload=unload_module,.reload=reload,) | |
static int | fmult (int an, int srn) |
static int | g726_decode (int i, struct g726_state *state_ptr) |
static int | g726_encode (int sl, struct g726_state *state_ptr) |
static void | g726_init_state (struct g726_state *state_ptr) |
static int | g726aal2tolin_framein (struct ast_trans_pvt *pvt, struct ast_frame *f) |
decode packed 4-bit G726 values (AAL2 packing) and store in buffer. | |
static int | g726tolin_framein (struct ast_trans_pvt *pvt, struct ast_frame *f) |
decode packed 4-bit G726 values (RFC3551 packing) and store in buffer. | |
static int | lintog726_framein (struct ast_trans_pvt *pvt, struct ast_frame *f) |
compress and store data (4-bit G726 samples, RFC3551 packing) in outbuf | |
static int | lintog726_new (struct ast_trans_pvt *pvt) |
init a new instance of g726_coder_pvt. | |
static int | lintog726aal2_framein (struct ast_trans_pvt *pvt, struct ast_frame *f) |
compress and store data (4-bit G726 samples, AAL2 packing) in outbuf | |
static int | load_module (void) |
static int | predictor_pole (struct g726_state *state_ptr) |
static int | predictor_zero (struct g726_state *state_ptr) |
static int | quan (int val, int *table, int size) |
static int | quantize (int d, int y, int *table, int size) |
static int | reconstruct (int sign, int dqln, int y) |
static int | reload (void) |
static int | step_size (struct g726_state *state_ptr) |
static int | unload_module (void) |
static void | update (int code_size, int y, int wi, int fi, int dq, int sr, int dqsez, struct g726_state *state_ptr) |
Variables | |
static int | _dqlntab [16] |
static int | _fitab [16] |
static int | _witab [16] |
static struct ast_translator | g726aal2tolin |
static struct ast_translator | g726tolin |
static struct ast_translator | lintog726 |
static struct ast_translator | lintog726aal2 |
static int | qtab_721 [7] = {-124, 80, 178, 246, 300, 349, 400} |
codec_g726.c - translate between signed linear and ITU G.726-32kbps (both RFC3551 and AAL2 codeword packing)
Definition in file codec_g726.c.
#define BUF_SHIFT 5 |
Definition at line 62 of file codec_g726.c.
#define BUFFER_SAMPLES 8096 |
Definition at line 61 of file codec_g726.c.
#define WANT_ASM |
Definition at line 45 of file codec_g726.c.
AST_MODULE_INFO | ( | ASTERISK_GPL_KEY | , | |
AST_MODFLAG_DEFAULT | , | |||
"ITU G.726-32kbps G726 Transcoder" | , | |||
. | load = load_module , |
|||
. | unload = unload_module , |
|||
. | reload = reload | |||
) |
static int fmult | ( | int | an, | |
int | srn | |||
) | [static] |
Definition at line 207 of file codec_g726.c.
References ilog2().
Referenced by predictor_pole(), and predictor_zero().
00208 { 00209 int anmag, anexp, anmant; 00210 int wanexp, wanmant; 00211 int retval; 00212 00213 anmag = (an > 0) ? an : ((-an) & 0x1FFF); 00214 anexp = ilog2(anmag) - 5; 00215 anmant = (anmag == 0) ? 32 : 00216 (anexp >= 0) ? anmag >> anexp : anmag << -anexp; 00217 wanexp = anexp + ((srn >> 6) & 0xF) - 13; 00218 00219 wanmant = (anmant * (srn & 077) + 0x30) >> 4; 00220 retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) : 00221 (wanmant >> -wanexp); 00222 00223 return (((an ^ srn) < 0) ? -retval : retval); 00224 }
static int g726_decode | ( | int | i, | |
struct g726_state * | state_ptr | |||
) | [static] |
Definition at line 580 of file codec_g726.c.
References predictor_pole(), predictor_zero(), reconstruct(), step_size(), and update().
Referenced by g726aal2tolin_framein(), and g726tolin_framein().
00581 { 00582 int sezi, sez, se; /* ACCUM */ 00583 int y; /* MIX */ 00584 int sr; /* ADDB */ 00585 int dq; 00586 int dqsez; 00587 00588 i &= 0x0f; /* mask to get proper bits */ 00589 #ifdef NOT_BLI 00590 sezi = predictor_zero(state_ptr); 00591 sez = sezi; 00592 se = sezi + predictor_pole(state_ptr); /* estimated signal */ 00593 #else 00594 sezi = predictor_zero(state_ptr); 00595 sez = sezi >> 1; 00596 se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */ 00597 #endif 00598 00599 y = step_size(state_ptr); /* dynamic quantizer step size */ 00600 00601 dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized diff. */ 00602 00603 #ifdef NOT_BLI 00604 sr = se + dq; /* reconst. signal */ 00605 dqsez = dq + sez; /* pole prediction diff. */ 00606 #else 00607 sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */ 00608 dqsez = sr - se + sez; /* pole prediction diff. */ 00609 #endif 00610 00611 update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr); 00612 00613 #ifdef NOT_BLI 00614 return (sr >> 10); /* sr was 26-bit dynamic range */ 00615 #else 00616 return (sr << 2); /* sr was 14-bit dynamic range */ 00617 #endif 00618 }
static int g726_encode | ( | int | sl, | |
struct g726_state * | state_ptr | |||
) | [static] |
Definition at line 626 of file codec_g726.c.
References predictor_pole(), predictor_zero(), quantize(), reconstruct(), step_size(), and update().
Referenced by lintog726_framein(), and lintog726aal2_framein().
00627 { 00628 int sezi, se, sez; /* ACCUM */ 00629 int d; /* SUBTA */ 00630 int sr; /* ADDB */ 00631 int y; /* MIX */ 00632 int dqsez; /* ADDC */ 00633 int dq, i; 00634 00635 #ifdef NOT_BLI 00636 sl <<= 10; /* 26-bit dynamic range */ 00637 00638 sezi = predictor_zero(state_ptr); 00639 sez = sezi; 00640 se = sezi + predictor_pole(state_ptr); /* estimated signal */ 00641 #else 00642 sl >>= 2; /* 14-bit dynamic range */ 00643 00644 sezi = predictor_zero(state_ptr); 00645 sez = sezi >> 1; 00646 se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */ 00647 #endif 00648 00649 d = sl - se; /* estimation difference */ 00650 00651 /* quantize the prediction difference */ 00652 y = step_size(state_ptr); /* quantizer step size */ 00653 #ifdef NOT_BLI 00654 d /= 0x1000; 00655 #endif 00656 i = quantize(d, y, qtab_721, 7); /* i = G726 code */ 00657 00658 dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized est diff */ 00659 00660 #ifdef NOT_BLI 00661 sr = se + dq; /* reconst. signal */ 00662 dqsez = dq + sez; /* pole prediction diff. */ 00663 #else 00664 sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */ 00665 dqsez = sr - se + sez; /* pole prediction diff. */ 00666 #endif 00667 00668 update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr); 00669 00670 return (i); 00671 }
static void g726_init_state | ( | struct g726_state * | state_ptr | ) | [static] |
Definition at line 125 of file codec_g726.c.
References g726_state::a, g726_state::ap, g726_state::b, g726_state::dml, g726_state::dms, g726_state::dq, g726_state::pk, g726_state::sr, g726_state::td, g726_state::yl, and g726_state::yu.
Referenced by lintog726_new().
00126 { 00127 int cnta; 00128 00129 state_ptr->yl = 34816; 00130 state_ptr->yu = 544; 00131 state_ptr->dms = 0; 00132 state_ptr->dml = 0; 00133 state_ptr->ap = 0; 00134 for (cnta = 0; cnta < 2; cnta++) { 00135 state_ptr->a[cnta] = 0; 00136 state_ptr->pk[cnta] = 0; 00137 #ifdef NOT_BLI 00138 state_ptr->sr[cnta] = 1; 00139 #else 00140 state_ptr->sr[cnta] = 32; 00141 #endif 00142 } 00143 for (cnta = 0; cnta < 6; cnta++) { 00144 state_ptr->b[cnta] = 0; 00145 #ifdef NOT_BLI 00146 state_ptr->dq[cnta] = 1; 00147 #else 00148 state_ptr->dq[cnta] = 32; 00149 #endif 00150 } 00151 state_ptr->td = 0; 00152 }
static int g726aal2tolin_framein | ( | struct ast_trans_pvt * | pvt, | |
struct ast_frame * | f | |||
) | [static] |
decode packed 4-bit G726 values (AAL2 packing) and store in buffer.
Definition at line 695 of file codec_g726.c.
References ast_frame::data, ast_trans_pvt::datalen, ast_frame::datalen, g726_coder_pvt::g726, g726_decode(), ast_trans_pvt::i16, ast_trans_pvt::outbuf, ast_frame::ptr, ast_trans_pvt::pvt, ast_frame::samples, and ast_trans_pvt::samples.
00696 { 00697 struct g726_coder_pvt *tmp = pvt->pvt; 00698 unsigned char *src = f->data.ptr; 00699 int16_t *dst = pvt->outbuf.i16 + pvt->samples; 00700 unsigned int i; 00701 00702 for (i = 0; i < f->datalen; i++) { 00703 *dst++ = g726_decode((src[i] >> 4) & 0xf, &tmp->g726); 00704 *dst++ = g726_decode(src[i] & 0x0f, &tmp->g726); 00705 } 00706 00707 pvt->samples += f->samples; 00708 pvt->datalen += 2 * f->samples; /* 2 bytes/sample */ 00709 00710 return 0; 00711 }
static int g726tolin_framein | ( | struct ast_trans_pvt * | pvt, | |
struct ast_frame * | f | |||
) | [static] |
decode packed 4-bit G726 values (RFC3551 packing) and store in buffer.
Definition at line 736 of file codec_g726.c.
References ast_frame::data, ast_trans_pvt::datalen, ast_frame::datalen, g726_coder_pvt::g726, g726_decode(), ast_trans_pvt::i16, ast_trans_pvt::outbuf, ast_frame::ptr, ast_trans_pvt::pvt, ast_frame::samples, and ast_trans_pvt::samples.
00737 { 00738 struct g726_coder_pvt *tmp = pvt->pvt; 00739 unsigned char *src = f->data.ptr; 00740 int16_t *dst = pvt->outbuf.i16 + pvt->samples; 00741 unsigned int i; 00742 00743 for (i = 0; i < f->datalen; i++) { 00744 *dst++ = g726_decode(src[i] & 0x0f, &tmp->g726); 00745 *dst++ = g726_decode((src[i] >> 4) & 0xf, &tmp->g726); 00746 } 00747 00748 pvt->samples += f->samples; 00749 pvt->datalen += 2 * f->samples; /* 2 bytes/sample */ 00750 00751 return 0; 00752 }
static int lintog726_framein | ( | struct ast_trans_pvt * | pvt, | |
struct ast_frame * | f | |||
) | [static] |
compress and store data (4-bit G726 samples, RFC3551 packing) in outbuf
Definition at line 755 of file codec_g726.c.
References ast_trans_pvt::c, ast_frame::data, ast_trans_pvt::datalen, g726_coder_pvt::g726, g726_encode(), g726_coder_pvt::next_flag, ast_trans_pvt::outbuf, ast_frame::ptr, ast_trans_pvt::pvt, ast_trans_pvt::samples, and ast_frame::samples.
00756 { 00757 struct g726_coder_pvt *tmp = pvt->pvt; 00758 int16_t *src = f->data.ptr; 00759 unsigned int i; 00760 00761 for (i = 0; i < f->samples; i++) { 00762 unsigned char d = g726_encode(src[i], &tmp->g726); /* this sample */ 00763 00764 if (tmp->next_flag & 0x80) { /* merge with leftover sample */ 00765 pvt->outbuf.c[pvt->datalen++] = (d << 4) | (tmp->next_flag & 0xf); 00766 pvt->samples += 2; /* 2 samples per byte */ 00767 tmp->next_flag = 0; 00768 } else { 00769 tmp->next_flag = 0x80 | d; 00770 } 00771 } 00772 00773 return 0; 00774 }
static int lintog726_new | ( | struct ast_trans_pvt * | pvt | ) | [static] |
init a new instance of g726_coder_pvt.
Definition at line 685 of file codec_g726.c.
References g726_coder_pvt::g726, g726_init_state(), and ast_trans_pvt::pvt.
00686 { 00687 struct g726_coder_pvt *tmp = pvt->pvt; 00688 00689 g726_init_state(&tmp->g726); 00690 00691 return 0; 00692 }
static int lintog726aal2_framein | ( | struct ast_trans_pvt * | pvt, | |
struct ast_frame * | f | |||
) | [static] |
compress and store data (4-bit G726 samples, AAL2 packing) in outbuf
Definition at line 714 of file codec_g726.c.
References ast_trans_pvt::c, ast_frame::data, ast_trans_pvt::datalen, g726_coder_pvt::g726, g726_encode(), g726_coder_pvt::next_flag, ast_trans_pvt::outbuf, ast_frame::ptr, ast_trans_pvt::pvt, ast_trans_pvt::samples, and ast_frame::samples.
00715 { 00716 struct g726_coder_pvt *tmp = pvt->pvt; 00717 int16_t *src = f->data.ptr; 00718 unsigned int i; 00719 00720 for (i = 0; i < f->samples; i++) { 00721 unsigned char d = g726_encode(src[i], &tmp->g726); /* this sample */ 00722 00723 if (tmp->next_flag & 0x80) { /* merge with leftover sample */ 00724 pvt->outbuf.c[pvt->datalen++] = ((tmp->next_flag & 0xf)<< 4) | d; 00725 pvt->samples += 2; /* 2 samples per byte */ 00726 tmp->next_flag = 0; 00727 } else { 00728 tmp->next_flag = 0x80 | d; 00729 } 00730 } 00731 00732 return 0; 00733 }
static int load_module | ( | void | ) | [static] |
Definition at line 842 of file codec_g726.c.
References AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_SUCCESS, ast_register_translator, and unload_module.
00843 { 00844 int res = 0; 00845 00846 res |= ast_register_translator(&g726tolin); 00847 res |= ast_register_translator(&lintog726); 00848 00849 res |= ast_register_translator(&g726aal2tolin); 00850 res |= ast_register_translator(&lintog726aal2); 00851 00852 if (res) { 00853 unload_module(); 00854 return AST_MODULE_LOAD_FAILURE; 00855 } 00856 00857 return AST_MODULE_LOAD_SUCCESS; 00858 }
static int predictor_pole | ( | struct g726_state * | state_ptr | ) | [static] |
Definition at line 235 of file codec_g726.c.
References g726_state::a, fmult(), and g726_state::sr.
Referenced by g726_decode(), and g726_encode().
static int predictor_zero | ( | struct g726_state * | state_ptr | ) | [static] |
Definition at line 226 of file codec_g726.c.
References g726_state::b, g726_state::dq, and fmult().
Referenced by g726_decode(), and g726_encode().
static int quan | ( | int | val, | |
int * | table, | |||
int | size | |||
) | [static] |
Definition at line 162 of file codec_g726.c.
Referenced by quantize().
static int quantize | ( | int | d, | |
int | y, | |||
int * | table, | |||
int | size | |||
) | [static] |
Definition at line 278 of file codec_g726.c.
References ilog2(), and quan().
Referenced by g726_encode().
00283 { 00284 int dqm; /* Magnitude of 'd' */ 00285 int exp; /* Integer part of base 2 log of 'd' */ 00286 int mant; /* Fractional part of base 2 log */ 00287 int dl; /* Log of magnitude of 'd' */ 00288 int dln; /* Step size scale factor normalized log */ 00289 int i; 00290 00291 /* 00292 * LOG 00293 * 00294 * Compute base 2 log of 'd', and store in 'dl'. 00295 */ 00296 dqm = abs(d); 00297 exp = ilog2(dqm); 00298 if (exp < 0) 00299 exp = 0; 00300 mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */ 00301 dl = (exp << 7) | mant; 00302 00303 /* 00304 * SUBTB 00305 * 00306 * "Divide" by step size multiplier. 00307 */ 00308 dln = dl - (y >> 2); 00309 00310 /* 00311 * QUAN 00312 * 00313 * Obtain codword i for 'd'. 00314 */ 00315 i = quan(dln, table, size); 00316 if (d < 0) /* take 1's complement of i */ 00317 return ((size << 1) + 1 - i); 00318 else if (i == 0) /* take 1's complement of 0 */ 00319 return ((size << 1) + 1); /* new in 1988 */ 00320 else 00321 return (i); 00322 }
static int reconstruct | ( | int | sign, | |
int | dqln, | |||
int | y | |||
) | [static] |
Definition at line 331 of file codec_g726.c.
Referenced by bridge_p2p_rtp_write(), g726_decode(), and g726_encode().
00335 { 00336 int dql; /* Log of 'dq' magnitude */ 00337 int dex; /* Integer part of log */ 00338 int dqt; 00339 int dq; /* Reconstructed difference signal sample */ 00340 00341 dql = dqln + (y >> 2); /* ADDA */ 00342 00343 if (dql < 0) { 00344 #ifdef NOT_BLI 00345 return (sign) ? -1 : 1; 00346 #else 00347 return (sign) ? -0x8000 : 0; 00348 #endif 00349 } else { /* ANTILOG */ 00350 dex = (dql >> 7) & 15; 00351 dqt = 128 + (dql & 127); 00352 #ifdef NOT_BLI 00353 dq = ((dqt << 19) >> (14 - dex)); 00354 return (sign) ? -dq : dq; 00355 #else 00356 dq = (dqt << 7) >> (14 - dex); 00357 return (sign) ? (dq - 0x8000) : dq; 00358 #endif 00359 } 00360 }
static int reload | ( | void | ) | [static] |
Definition at line 824 of file codec_g726.c.
References AST_MODULE_LOAD_SUCCESS.
00825 { 00826 return AST_MODULE_LOAD_SUCCESS; 00827 }
static int step_size | ( | struct g726_state * | state_ptr | ) | [static] |
Definition at line 249 of file codec_g726.c.
References g726_state::ap, g726_state::yl, and g726_state::yu.
Referenced by g726_decode(), g726_encode(), and smb_pitch_shift().
00250 { 00251 int y; 00252 int dif; 00253 int al; 00254 00255 if (state_ptr->ap >= 256) 00256 return (state_ptr->yu); 00257 else { 00258 y = state_ptr->yl >> 6; 00259 dif = state_ptr->yu - y; 00260 al = state_ptr->ap >> 2; 00261 if (dif > 0) 00262 y += (dif * al) >> 6; 00263 else if (dif < 0) 00264 y += (dif * al + 0x3F) >> 6; 00265 return (y); 00266 } 00267 }
static int unload_module | ( | void | ) | [static] |
Definition at line 829 of file codec_g726.c.
References ast_unregister_translator().
00830 { 00831 int res = 0; 00832 00833 res |= ast_unregister_translator(&g726tolin); 00834 res |= ast_unregister_translator(&lintog726); 00835 00836 res |= ast_unregister_translator(&g726aal2tolin); 00837 res |= ast_unregister_translator(&lintog726aal2); 00838 00839 return res; 00840 }
static void update | ( | int | code_size, | |
int | y, | |||
int | wi, | |||
int | fi, | |||
int | dq, | |||
int | sr, | |||
int | dqsez, | |||
struct g726_state * | state_ptr | |||
) | [static] |
Definition at line 367 of file codec_g726.c.
References g726_state::a, g726_state::ap, g726_state::b, g726_state::dml, g726_state::dms, g726_state::dq, ilog2(), g726_state::pk, g726_state::sr, g726_state::td, g726_state::yl, and g726_state::yu.
Referenced by config_device(), config_line(), connectedline_write(), g726_decode(), g726_encode(), load_pktccops_config(), and redirecting_write().
00376 { 00377 int cnt; 00378 int mag; /* Adaptive predictor, FLOAT A */ 00379 #ifndef NOT_BLI 00380 int exp; 00381 #endif 00382 int a2p=0; /* LIMC */ 00383 int a1ul; /* UPA1 */ 00384 int pks1; /* UPA2 */ 00385 int fa1; 00386 int tr; /* tone/transition detector */ 00387 int ylint, thr2, dqthr; 00388 int ylfrac, thr1; 00389 int pk0; 00390 00391 pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */ 00392 00393 #ifdef NOT_BLI 00394 mag = abs(dq / 0x1000); /* prediction difference magnitude */ 00395 #else 00396 mag = dq & 0x7FFF; /* prediction difference magnitude */ 00397 #endif 00398 /* TRANS */ 00399 ylint = state_ptr->yl >> 15; /* exponent part of yl */ 00400 ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */ 00401 thr1 = (32 + ylfrac) << ylint; /* threshold */ 00402 thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */ 00403 dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */ 00404 if (state_ptr->td == 0) /* signal supposed voice */ 00405 tr = 0; 00406 else if (mag <= dqthr) /* supposed data, but small mag */ 00407 tr = 0; /* treated as voice */ 00408 else /* signal is data (modem) */ 00409 tr = 1; 00410 00411 /* 00412 * Quantizer scale factor adaptation. 00413 */ 00414 00415 /* FUNCTW & FILTD & DELAY */ 00416 /* update non-steady state step size multiplier */ 00417 state_ptr->yu = y + ((wi - y) >> 5); 00418 00419 /* LIMB */ 00420 if (state_ptr->yu < 544) /* 544 <= yu <= 5120 */ 00421 state_ptr->yu = 544; 00422 else if (state_ptr->yu > 5120) 00423 state_ptr->yu = 5120; 00424 00425 /* FILTE & DELAY */ 00426 /* update steady state step size multiplier */ 00427 state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6); 00428 00429 /* 00430 * Adaptive predictor coefficients. 00431 */ 00432 if (tr == 1) { /* reset a's and b's for modem signal */ 00433 state_ptr->a[0] = 0; 00434 state_ptr->a[1] = 0; 00435 state_ptr->b[0] = 0; 00436 state_ptr->b[1] = 0; 00437 state_ptr->b[2] = 0; 00438 state_ptr->b[3] = 0; 00439 state_ptr->b[4] = 0; 00440 state_ptr->b[5] = 0; 00441 } else { /* update a's and b's */ 00442 pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */ 00443 00444 /* update predictor pole a[1] */ 00445 a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7); 00446 if (dqsez != 0) { 00447 fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0]; 00448 if (fa1 < -8191) /* a2p = function of fa1 */ 00449 a2p -= 0x100; 00450 else if (fa1 > 8191) 00451 a2p += 0xFF; 00452 else 00453 a2p += fa1 >> 5; 00454 00455 if (pk0 ^ state_ptr->pk[1]) 00456 /* LIMC */ 00457 if (a2p <= -12160) 00458 a2p = -12288; 00459 else if (a2p >= 12416) 00460 a2p = 12288; 00461 else 00462 a2p -= 0x80; 00463 else if (a2p <= -12416) 00464 a2p = -12288; 00465 else if (a2p >= 12160) 00466 a2p = 12288; 00467 else 00468 a2p += 0x80; 00469 } 00470 00471 /* TRIGB & DELAY */ 00472 state_ptr->a[1] = a2p; 00473 00474 /* UPA1 */ 00475 /* update predictor pole a[0] */ 00476 state_ptr->a[0] -= state_ptr->a[0] >> 8; 00477 if (dqsez != 0) { 00478 if (pks1 == 0) 00479 state_ptr->a[0] += 192; 00480 else 00481 state_ptr->a[0] -= 192; 00482 } 00483 /* LIMD */ 00484 a1ul = 15360 - a2p; 00485 if (state_ptr->a[0] < -a1ul) 00486 state_ptr->a[0] = -a1ul; 00487 else if (state_ptr->a[0] > a1ul) 00488 state_ptr->a[0] = a1ul; 00489 00490 /* UPB : update predictor zeros b[6] */ 00491 for (cnt = 0; cnt < 6; cnt++) { 00492 if (code_size == 5) /* for 40Kbps G.723 */ 00493 state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9; 00494 else /* for G.721 and 24Kbps G.723 */ 00495 state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8; 00496 if (mag) 00497 { /* XOR */ 00498 if ((dq ^ state_ptr->dq[cnt]) >= 0) 00499 state_ptr->b[cnt] += 128; 00500 else 00501 state_ptr->b[cnt] -= 128; 00502 } 00503 } 00504 } 00505 00506 for (cnt = 5; cnt > 0; cnt--) 00507 state_ptr->dq[cnt] = state_ptr->dq[cnt-1]; 00508 #ifdef NOT_BLI 00509 state_ptr->dq[0] = dq; 00510 #else 00511 /* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */ 00512 if (mag == 0) { 00513 state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0x20 - 0x400; 00514 } else { 00515 exp = ilog2(mag) + 1; 00516 state_ptr->dq[0] = (dq >= 0) ? 00517 (exp << 6) + ((mag << 6) >> exp) : 00518 (exp << 6) + ((mag << 6) >> exp) - 0x400; 00519 } 00520 #endif 00521 00522 state_ptr->sr[1] = state_ptr->sr[0]; 00523 #ifdef NOT_BLI 00524 state_ptr->sr[0] = sr; 00525 #else 00526 /* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */ 00527 if (sr == 0) { 00528 state_ptr->sr[0] = 0x20; 00529 } else if (sr > 0) { 00530 exp = ilog2(sr) + 1; 00531 state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp); 00532 } else if (sr > -0x8000) { 00533 mag = -sr; 00534 exp = ilog2(mag) + 1; 00535 state_ptr->sr[0] = (exp << 6) + ((mag << 6) >> exp) - 0x400; 00536 } else 00537 state_ptr->sr[0] = 0x20 - 0x400; 00538 #endif 00539 00540 /* DELAY A */ 00541 state_ptr->pk[1] = state_ptr->pk[0]; 00542 state_ptr->pk[0] = pk0; 00543 00544 /* TONE */ 00545 if (tr == 1) /* this sample has been treated as data */ 00546 state_ptr->td = 0; /* next one will be treated as voice */ 00547 else if (a2p < -11776) /* small sample-to-sample correlation */ 00548 state_ptr->td = 1; /* signal may be data */ 00549 else /* signal is voice */ 00550 state_ptr->td = 0; 00551 00552 /* 00553 * Adaptation speed control. 00554 */ 00555 state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */ 00556 state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */ 00557 00558 if (tr == 1) 00559 state_ptr->ap = 256; 00560 else if (y < 1536) /* SUBTC */ 00561 state_ptr->ap += (0x200 - state_ptr->ap) >> 4; 00562 else if (state_ptr->td == 1) 00563 state_ptr->ap += (0x200 - state_ptr->ap) >> 4; 00564 else if (abs((state_ptr->dms << 2) - state_ptr->dml) >= 00565 (state_ptr->dml >> 3)) 00566 state_ptr->ap += (0x200 - state_ptr->ap) >> 4; 00567 else 00568 state_ptr->ap += (-state_ptr->ap) >> 4; 00569 }
int _dqlntab[16] [static] |
{-2048, 4, 135, 213, 273, 323, 373, 425, 425, 373, 323, 273, 213, 135, 4, -2048}
Definition at line 103 of file codec_g726.c.
int _fitab[16] [static] |
{0, 0, 0, 0x200, 0x200, 0x200, 0x600, 0xE00, 0xE00, 0x600, 0x200, 0x200, 0x200, 0, 0, 0}
Definition at line 114 of file codec_g726.c.
int _witab[16] [static] |
{-12, 18, 41, 64, 112, 198, 355, 1122, 1122, 355, 198, 112, 64, 41, 18, -12}
Definition at line 107 of file codec_g726.c.
struct ast_translator g726aal2tolin [static] |
Definition at line 800 of file codec_g726.c.
struct ast_translator g726tolin [static] |
Definition at line 776 of file codec_g726.c.
struct ast_translator lintog726 [static] |
Definition at line 788 of file codec_g726.c.
struct ast_translator lintog726aal2 [static] |
Definition at line 812 of file codec_g726.c.
int qtab_721[7] = {-124, 80, 178, 246, 300, 349, 400} [static] |
Definition at line 98 of file codec_g726.c.