coeff.c

2400bps MELP语音编解码源程序。

/*

2.4 kbps MELP Proposed Federal Standard speech coder

Fixed-point C code, version 1.0

Copyright (c) 1998, Texas Instruments, Inc.  

Texas Instruments has intellectual property rights on the MELP
algorithm.  The Texas Instruments contact for licensing issues for
commercial and non-government use is William Gordon, Director,
Government Contracts, Texas Instruments Incorporated, Semiconductor
Group (phone [phone]).

The fixed-point version of the voice codec Mixed Excitation Linear
Prediction (MELP) is based on specifications on the C-language software
simulation contained in GSM 06.06 which is protected by copyright and
is the property of the European Telecommunications Standards Institute
(ETSI). This standard is available from the ETSI publication office
tel. [phone]. ETSI has granted a license to United States
Department of Defense to use the C-language software simulation contained
in GSM 06.06 for the purposes of the development of a fixed-point
version of the voice codec Mixed Excitation Linear Prediction (MELP).
Requests for authorization to make other use of the GSM 06.06 or
otherwise distribute or modify them need to be addressed to the ETSI
Secretariat fax: [phone].


*/
/*  Coeff.c: filter coefficient file */
/*                                   */
/*                                                                  */
/* (C) 1997  Texas Instruments                                      */
/*                                                                  */
#include	<stdio.h>
#include "mathhalf.h"
#include "melp.h"

/* Lowpass filter coefficient in second-order sections */
/* Butterworth, 6th order, Cutoff at 1 kHz */
/* matlab commands: [z,p,k]=butter(6,1000/4000);  */
/*                      sos=zp2sos(z,p,k);        */
/* Q13 */
Shortword lpf_num[(LPF_ORD/2)*3] = {
        713, 1426, 713,
	798, 1600, 801,
	1016, 2028, 1012};
/* sign of coefficients for lpf_den is reversed */
Shortword lpf_den[(LPF_ORD/2)*3] = {
        -8192, 6884, -1543, 
	-8192, 7723, -2731, 
	-8192, 9793, -5657};

/* Butterworth bandpass filters in second-order sections */
/* matlab scrpt: ~wmlai/dod/fixedpt/bp_sos_fxp.m */
/* Q13 */
Shortword bpf_num[NUM_BANDS*((BPF_ORD/2)*3)] = {
	285, 567, 283,        /* lowpass, cutoff at 500 Hz */
	245, 491, 245,
        227, 455, 228,

	5001, -10001, 5001,   /* bandpass, pass band at 500-1000 Hz */
	429, 857, 429,
	1359, 0, -1359,

	4470, -8941, 4470,    /* bandpass, pass band at 1000-2000 Hz */
	1624, 3248, 1624,
	2399, 0, -2399,

	4470, 8941, 4470,     /* bandpass, pass band at 2000-3000 Hz */
	1624, -3248, 1624,
	2399, 0, -2399,

	1020, -2028, 1008,    /* highpass, cutoff at 3000 Hz */
	795, -1599, 805,
	713, -1426, 713};

/* sign of coefficients for bpf_den is reversed */
Shortword bpf_den[NUM_BANDS*((BPF_ORD/2)*3)] = {
	-8192, 13772, -6715,      /* lowpass, cutoff at 500 Hz */
	-8192, 11913, -4703,
        -8192, 11051, -3770,

	-8192, 14036, -7108,      /* bandpass, pass band at 500-1000 Hz */
	-8192, 10624, -6408,
	-8192, 11585, -5474,

	-8192, 9687, -6002,       /* bandpass, pass band at 1000-2000 Hz */
	-8192, 645, -5339,
	-8192, 4799, -3393,

	-8192, -9687, -6002,      /* bandpass, pass band at 2000-3000 Hz */
	-8192, -645, -5339,
	-8192, -4799, -3393,

	-8192, -9793, -5657,      /* highpass, cutoff at 3000 Hz */
	-8192, -7723, -2731,
	-8192, -6883, -1543};

/* Hamming window coefficents in Q15 */
Shortword win_cof[LPC_FRAME] = {
        2621,
	2628,
	2651,
	2689,
	2741,
	2808,
	2891,
	2988,
	3099,
	3225,
	3366,
	3521,
	3690,
	3873,
	4070,
	4280,
	4504,
	4741,
	4990,
	5253,
	5528,
	5815,
	6113,
	6424,
	6745,
	7078,
	7421,
	7774,
	8138,
	8510,
	8892,
	9283,
	9682,
	10089,
	10504,
	10925,
	11354,
	11789,
	12230,
	12676,
	13127,
	13583,
	14043,
	14506,
	14973,
	15442,
	15914,
	16387,
	16862,
	17337,
	17813,
	18289,
	18764,
	19238,
	19711,
	20181,
	20649,
	21115,
	21576,
	22034,
	22488,
	22936,
	23380,
	23818,
	24250,
	24675,
	25093,
	25504,
	25907,
	26302,
	26688,
	27066,
	27434,
	27792,
	28140,
	28478,
	28805,
	29121,
	29426,
	29719,
	30000,
	30268,
	30524,
	30768,
	30998,
	31215,
	31419,
	31609,
	31785,
	31947,
	32094,
	32228,
	32347,
	32451,
	32541,
	32616,
	32676,
	32721,
	32751,
	32766,
	32766,
	32751,
	32721,
	32676,
	32616,
	32541,
	32451,
	32347,
	32228,
	32094,
	31947,
	31785,
	31609,
	31419,
	31215,
	30998,
	30768,
	30524,
	30268,
	30000,
	29719,
	29426,
	29121,
	28805,
	28478,
	28140,
	27792,
	27434,
	27066,
	26688,
	26302,
	25907,
	25504,
	25093,
	24675,
	24250,
	23818,
	23380,
	22936,
	22488,
	22034,
	21576,
	21115,
	20649,
	20181,
	19711,
	19238,
	18764,
	18289,
	17813,
	17337,
	16862,
	16387,
	15914,
	15442,
	14973,
	14506,
	14043,
	13583,
	13127,
	12676,
	12230,
	11789,
	11354,
	10925,
	10504,
	10089,
	9682,
	9283,
	8892,
	8510,
	8138,
	7774,
	7421,
	7078,
	6745,
	6424,
	6113,
	5815,
	5528,
	5253,
	4990,
	4741,
	4504,
	4280,
	4070,
	3873,
	3690,
	3521,
	3366,
	3225,
	3099,
	2988,
	2891,
	2808,
	2741,
	2689,
	2651,
	2628,
	2621};

/* Bandpass filter coeffients */
Shortword bp_cof[NUM_BANDS][MIX_ORD+1] = {
{
        0,        /* lowpass, cutoff at 500 Hz */
      -50,
     -115,
     -185,
     -245,
     -274,
     -253,
     -165,
        0,
      242,
      548,
      897,
     1257,
     1590,
     1860,
     2036,
     2097,
     2036,
     1860,
     1590,
     1257,
      897,
      548,
      242,
        0,
     -165,
     -253,
     -274,
     -245,
     -185,
     -115,
      -50,
	0
},
{
        0,      /* bandpass, pass band at 500-1000 Hz */
      -41,
      -46,
       42,
      238,
      470,
      593,
      456,
        0,
     -668,
    -1286,
    -1539,
    -1221,
     -362,
      748,
     1677,
     2037,
     1677,
      748,
     -362,
    -1221,
    -1539,
    -1286,
     -668,
        0,
      456,
      593,
      470,
      238,
       42,
      -46,
      -41,
        0
},
{
        0,      /* bandpass, pass band at 1000-2000 Hz */
      -38,
      162,
      342,
        0,
     -506,
     -357,
      126,
        0,
     -185,
      774,
     1656,
        0,
    -2933,
    -2627,
     1556,
     4188,
     1556,
    -2627,
    -2933,
        0,
     1656,
      774,
     -185,
        0,
      126,
     -357,
     -506,
        0,
      342,
      162,
      -38,
        0
},
{
        0,      /* bandpass, pass band at 2000-3000 Hz */
       38,
      162,
     -342,
        0,
      506,
     -357,
     -126,
        0,
      185,
      774,
    -1656,
        0,
     2933,
    -2627,
    -1556,
     4188,
    -1556,
    -2627,
     2933,
        0,
    -1656,
      774,
      185,
        0,
     -126,
     -357,
      506,
        0,
     -342,
      162,
       38,
	0
},
{
        0,      /* highpass, cutoff at 3000 Hz */
       91,
     -161,
      140,
        0,
     -208,
      354,
     -302,
        0,
      442,
     -768,
      680,
        0,
    -1205,
     2604,
    -3725,
     4153,
    -3725,
     2604,
    -1205,
        0,
      680,
     -768,
      442,
        0,
     -302,
      354,
     -208,
        0,
      140,
     -161,
       91,
        0}};

/* Triangle pulse dispersion filter */
Shortword disp_cof[DISP_ORD+1] = {
    -5670,
     -461,
      401,
     3724,
       65,
        0,
     1484,
      -30,
      -34,
      836,
    -2077,
      -40,
      463,
     7971,
     -579,
       -6,
     1923,
     -107,
      199,
      902,
    -1098,
      197,
      471,
    27150,
       11,
     -118,
     2406,
     -170,
      425,
      960,
     -652,
      399,
      387,
   -12755,
      236,
     -378,
     2761,
     -117,
      705,
      973,
     -409,
      608,
       25,
    -2539,
      408,
     -892,
     2381,
      155,
     1156,
      876,
     -244,
      846,
        6,
     -926,
      564,
    -1967,
    -2319,
      300,
     1993,
      592,
     -104,
     1129,
        9,
     -345,
      710};