tab_lbc.c

一个非常好用的国际标准G。726算法

/*
    ITU-T G.723 Speech Coder   ANSI-C Source Code Version 5.0
    copyright (c) 1995, AudioCodes, DSP Group, France Telecom,
    Universite de Sherbrooke.  All rights reserved.
*/


#include "typedef.h"
#include "cst_lbc.h"
#include "tab_lbc.h"

/*
**
** File:        tab_lbc.c
**
** Description: Tables used for G.723 encoding and decoding
**  
** Tables:      HammingWindowTable[180]
**
**              LPC Computation and Filtering
**
**                  BinomialWindowTable[10]
**                  BandExpTable[10]
**
**              LSP calculation and quantization
**
**                  CosineTable[512]
**                  LspDcTable[10]
**                  BandInfoTable[3][2]
**                  Band0Tb8[256*3]
**                  Band1Tb8[256*3]
**                  Band2Tb8[256*4]
**                  BandQntTable[3]
**
**              Perceptual Filtering and Post Filtering
**

**                  PerFiltZeroTable[10]
**                  PerFiltPoleTable[10]
**                  PostFiltZeroTable[10]
**                  PostFiltPoleTable[10]
**                  LpfConstTable[2] (pitch postfilter)
**
**              ACELP or MP-MLQ
**
**                  Nb_puls[4] (MP-MLQ)
**                  FcbkGainTable[24] (ACELP and MP-MLQ)
**                  MaxPosTable[4]  (MP-MLQ), Word32
**                  CombinatorialTable[6][30](MP-MLQ),Word32
**                  epsi170[170] (ACELP)
**                  gain170[170] (ACELP)
**
**              Pitch Prediction
**
**                  AcbkGainTable085[85*20]
**                  AcbkGainTable170[170*20]
**                  AcbkGainTablePtr[2]
**
**              Taming procedure
**
**                  tabgain170[170]
**                  tabgain85[85]
**
**              Comfort Noise Generation
**
**                  fact[4]
**                  L_bseg[3], Word32
**                  base[3]
**
**
**              All tables are Word16 unless separately denoted
*/

/*
**  HammingWindowTable:
**
**  Hamming Window coefficients scaled by 32768 (Q15).
**
*/

Word16   HammingWindowTable[LpcFrame] = {
    2621 ,
    2631 ,
    2659 ,
    2705 ,
    2770 ,
    2853 ,
    2955 ,
    3074 ,
    3212 ,
    3367 ,
    3541 ,
    3731 ,
    3939 ,
    4164 ,
    4405 ,
    4663 ,
    4937 ,
    5226 ,
    5531 ,
    5851 ,
    6186 ,
    6534 ,
    6897 ,
    7273 ,
    7661 ,
    8062 ,
    8475 ,
    8899 ,
    9334 ,
    9780 ,
   10235 ,
   10699 ,
   11172 ,
   11653 ,
   12141 ,
   12636 ,
   13138 ,
   13645 ,
   14157 ,
   14673 ,
   15193 ,
   15716 ,
   16242 ,
   16769 ,
   17298 ,
   17827 ,
   18356 ,
   18884 ,
   19411 ,
   19935 ,
   20457 ,
   20975 ,
   21489 ,
   21999 ,
   22503 ,
   23002 ,
   23494 ,
   23978 ,
   24455 ,
   24924 ,
   25384 ,
   25834 ,
   26274 ,
   26704 ,
   27122 ,
   27529 ,
   27924 ,
   28306 ,
   28675 ,
   29031 ,
   29373 ,
   29700 ,
   30012 ,
   30310 ,
   30592 ,
   30857 ,
   31107 ,
   31340 ,
   31557 ,
   31756 ,
   31938 ,
   32102 ,
   32249 ,
   32377 ,
   32488 ,
   32580 ,
   32654 ,
   32710 ,
   32747 ,
   32766 ,
   32766 ,
   32747 ,
   32710 ,
   32654 ,
   32580 ,
   32488 ,
   32377 ,
   32249 ,
   32102 ,
   31938 ,
   31756 ,
   31557 ,
   31340 ,
   31107 ,
   30857 ,
   30592 ,
   30310 ,
   30012 ,
   29700 ,
   29373 ,
   29031 ,
   28675 ,
   28306 ,
   27924 ,
   27529 ,
   27122 ,
   26704 ,
   26274 ,
   25834 ,
   25384 ,
   24924 ,
   24455 ,
   23978 ,
   23494 ,
   23002 ,
   22503 ,
   21999 ,
   21489 ,
   20975 ,
   20457 ,
   19935 ,
   19411 ,
   18884 ,
   18356 ,
   17827 ,
   17298 ,
   16769 ,
   16242 ,
   15716 ,
   15193 ,
   14673 ,
   14157 ,
   13645 ,
   13138 ,
   12636 ,
   12141 ,
   11653 ,
   11172 ,
   10699 ,
   10235 ,
    9780 ,
    9334 ,
    8899 ,
    8475 ,
    8062 ,
    7661 ,
    7273 ,
    6897 ,
    6534 ,
    6186 ,
    5851 ,
    5531 ,
    5226 ,
    4937 ,
    4663 ,
    4405 ,
    4164 ,
    3939 ,
    3731 ,
    3541 ,
    3367 ,
    3212 ,
    3074 ,
    2955 ,
    2853 ,
    2770 ,
    2705 ,
    2659 ,
    2631 ,
    2621 ,
   } ;

/*
**  BinomialWindowTable:
**
**  Purpose:
**     Binomial Window coefficients used to weight the autocorrelation before
**     Levinson-Durbin in the LPC coefficient calculation.  
**
**     Table Structure:
**     Coefficients are scaled by 32768 (Q15).
**
*/

Word16   BinomialWindowTable[LpcOrder] = {
     32749 ,
     32695 ,
     32604 ,
     32477 ,
     32315 ,
     32118 ,
     31887 ,
     31622 ,
     31324 ,
     30995 ,
   } ;

/*
**  BandExpTable:
**
**  Purpose:
**      Do bandwidth expansion on the LPC coefficients by scaling the
**      poles of the LPC synthesis filter by a factor of 0.994

**
**  Table Structure:
**      Table values correspond to (0.994) to the power of x,
**      where x = [0,..,10].
**      These values are scaled by 32768 (Q15).
**
*/

Word16   BandExpTable[LpcOrder] = {
     32571 ,  
     32376 ,
     32182 ,
     31989 ,
     31797 ,
     31606 ,
     31416 ,
     31228 ,
     31040 ,
     30854 ,
   } ;
   
/*
**  CosineTable:
**
**  Purpose:
**      Used to evaluate polynomial for LSP-LPC conversion
**
**  Table Structure:
**      Contains one period of a cosine wave.  Amplitude has been
**      scaled to go between 0 and 16384 instead of 0 and 1.
**
*/

Word16   CosineTable[CosineTableSize] = {
 16384 ,
 16383 ,
 16379 ,
 16373 ,
 16364 ,
 16353 ,
 16340 ,
 16324 ,
 16305 ,
 16284 ,
 16261 ,
 16235 ,
 16207 ,
 16176 ,
 16143 ,
 16107 ,
 16069 ,
 16029 ,
 15986 ,
 15941 ,
 15893 ,
 15843 ,
 15791 ,
 15736 ,
 15679 ,
 15619 ,
 15557 ,
 15493 ,
 15426 ,
 15357 ,
 15286 ,
 15213 ,
 15137 ,
 15059 ,
 14978 ,
 14896 ,
 14811 ,
 14724 ,
 14635 ,
 14543 ,
 14449 ,
 14354 ,
 14256 ,
 14155 ,
 14053 ,
 13949 ,
 13842 ,
 13733 ,
 13623 ,
 13510 ,
 13395 ,
 13279 ,
 13160 ,
 13039 ,
 12916 ,
 12792 ,
 12665 ,
 12537 ,
 12406 ,
 12274 ,
 12140 ,
 12004 ,
 11866 ,
 11727 ,
 11585 ,
 11442 ,
 11297 ,
 11151 ,
 11003 ,
 10853 ,
 10702 ,
 10549 ,
 10394 ,
 10238 ,
 10080 ,
 9921  ,
 9760  ,
 9598  ,
 9434  ,
 9269  ,
 9102  ,
 8935  ,
 8765  ,
 8595  ,
 8423  ,
 8250  ,
 8076  ,
 7900  ,
 7723  ,
 7545  ,
 7366  ,
 7186  ,
 7005  ,
 6823  ,
 6639  ,
 6455  ,
 6270  ,
 6084  ,
 5897  ,
 5708  ,
 5520  ,
 5330  ,
 5139  ,
 4948  ,
 4756  ,
 4563  ,
 4370  ,
 4176  ,
 3981  ,
 3786  ,
 3590  ,
 3393  ,
 3196  ,
 2999  ,
 2801  ,
 2603  ,
 2404  ,
 2205  ,
 2006  ,
 1806  ,
 1606  ,
 1406  ,
 1205  ,
 1005  ,
 804   ,
 603   ,
 402   ,
 201   ,
 0     ,
 -201  ,
 -402  ,
 -603  ,
 -804  ,
 -1005 ,
 -1205 ,
 -1406 ,
 -1606 ,
 -1806 ,
 -2006 ,
 -2205 ,
 -2404 ,
 -2603 ,
 -2801 ,
 -2999 ,
 -3196 ,
 -3393 ,
 -3590 ,
 -3786 ,
 -3981 ,
 -4176 ,
 -4370 ,
 -4563 ,
 -4756 ,
 -4948 ,
 -5139 ,
 -5330 ,
 -5520 ,
 -5708 ,
 -5897 ,
 -6084 ,
 -6270 ,
 -6455 ,
 -6639 ,
 -6823 ,
 -7005 ,
 -7186 ,
 -7366 ,
 -7545 ,
 -7723 ,