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2 /******************************************************************
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3
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4 iLBC Speech Coder ANSI-C Source Code
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5
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6 StateSearchW.c
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7
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8 Copyright (C) The Internet Society (2004).
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9 All Rights Reserved.
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10
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11 ******************************************************************/
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12
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13 #include <math.h>
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14 #include <string.h>
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15
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16 #include "iLBC_define.h"
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17 #include "constants.h"
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18 #include "filter.h"
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19 #include "helpfun.h"
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20
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21 /*----------------------------------------------------------------*
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22 * predictive noise shaping encoding of scaled start state
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23 * (subrutine for StateSearchW)
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24 *---------------------------------------------------------------*/
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25
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26 void AbsQuantW(iLBC_Enc_Inst_t * iLBCenc_inst,
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27 /* (i) Encoder instance */
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28 float *in, /* (i) vector to encode */
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29 float *syntDenum, /* (i) denominator of synthesis filter */
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30 float *weightDenum, /* (i) denominator of weighting filter */
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31 int *out, /* (o) vector of quantizer indexes */
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32 int len, /* (i) length of vector to encode and
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33 vector of quantizer indexes */
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34 int state_first /* (i) position of start state in the
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35 80 vec */
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36 )
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37 {
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38 float *syntOut;
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39 float syntOutBuf[LPC_FILTERORDER + STATE_SHORT_LEN_30MS];
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40 float toQ, xq;
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41 int n;
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42 int index;
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43
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44 /* initialization of buffer for filtering */
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45
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46 memset(syntOutBuf, 0, LPC_FILTERORDER * sizeof(float));
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47
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48
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49
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50
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51
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52
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53 /* initialization of pointer for filtering */
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54
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55 syntOut = &syntOutBuf[LPC_FILTERORDER];
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56
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57 /* synthesis and weighting filters on input */
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58
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59 if (state_first) {
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60 AllPoleFilter(in, weightDenum, SUBL, LPC_FILTERORDER);
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61 } else {
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62 AllPoleFilter(in, weightDenum,
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63 iLBCenc_inst->state_short_len - SUBL, LPC_FILTERORDER);
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64 }
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65
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66 /* encoding loop */
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67
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68 for (n = 0; n < len; n++) {
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69
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70 /* time update of filter coefficients */
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71
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72 if ((state_first) && (n == SUBL)) {
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73 syntDenum += (LPC_FILTERORDER + 1);
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74 weightDenum += (LPC_FILTERORDER + 1);
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75
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76 /* synthesis and weighting filters on input */
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77 AllPoleFilter(&in[n], weightDenum, len - n, LPC_FILTERORDER);
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78
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79 } else if ((state_first == 0) &&
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80 (n == (iLBCenc_inst->state_short_len - SUBL))) {
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81 syntDenum += (LPC_FILTERORDER + 1);
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82 weightDenum += (LPC_FILTERORDER + 1);
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83
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84 /* synthesis and weighting filters on input */
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85 AllPoleFilter(&in[n], weightDenum, len - n, LPC_FILTERORDER);
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86
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87 }
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88
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89 /* prediction of synthesized and weighted input */
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90
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91 syntOut[n] = 0.0;
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92 AllPoleFilter(&syntOut[n], weightDenum, 1, LPC_FILTERORDER);
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93
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94 /* quantization */
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95
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96 toQ = in[n] - syntOut[n];
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97
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98
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99
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100
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101
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102 sort_sq(&xq, &index, toQ, state_sq3Tbl, 8);
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103 out[n] = index;
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104 syntOut[n] = state_sq3Tbl[out[n]];
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105
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106 /* update of the prediction filter */
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107
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108 AllPoleFilter(&syntOut[n], weightDenum, 1, LPC_FILTERORDER);
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109 }
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110 }
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111
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112 /*----------------------------------------------------------------*
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113 * encoding of start state
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114 *---------------------------------------------------------------*/
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115
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116 void StateSearchW(iLBC_Enc_Inst_t * iLBCenc_inst,
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117 /* (i) Encoder instance */
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118 float *residual, /* (i) target residual vector */
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119 float *syntDenum, /* (i) lpc synthesis filter */
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120 float *weightDenum, /* (i) weighting filter denuminator */
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121 int *idxForMax, /* (o) quantizer index for maximum
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122 amplitude */
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123 int *idxVec, /* (o) vector of quantization indexes */
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124 int len, /* (i) length of all vectors */
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125 int state_first /* (i) position of start state in the
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126 80 vec */
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127 )
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128 {
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129 float dtmp, maxVal;
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130 float tmpbuf[LPC_FILTERORDER + 2 * STATE_SHORT_LEN_30MS];
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131 float *tmp, numerator[1 + LPC_FILTERORDER];
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132 float foutbuf[LPC_FILTERORDER + 2 * STATE_SHORT_LEN_30MS], *fout;
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133 int k;
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134 float qmax, scal;
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135
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136 /* initialization of buffers and filter coefficients */
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137
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138 memset(tmpbuf, 0, LPC_FILTERORDER * sizeof(float));
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139 memset(foutbuf, 0, LPC_FILTERORDER * sizeof(float));
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140 for (k = 0; k < LPC_FILTERORDER; k++) {
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141 numerator[k] = syntDenum[LPC_FILTERORDER - k];
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142 }
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143 numerator[LPC_FILTERORDER] = syntDenum[0];
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144 tmp = &tmpbuf[LPC_FILTERORDER];
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145 fout = &foutbuf[LPC_FILTERORDER];
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146
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147 /* circular convolution with the all-pass filter */
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148
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149
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150
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151
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152
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153
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154 memcpy(tmp, residual, len * sizeof(float));
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155 memset(tmp + len, 0, len * sizeof(float));
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156 ZeroPoleFilter(tmp, numerator, syntDenum, 2 * len,
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157 LPC_FILTERORDER, fout);
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158 for (k = 0; k < len; k++) {
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159 fout[k] += fout[k + len];
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160 }
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161
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162 /* identification of the maximum amplitude value */
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163
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164 maxVal = fout[0];
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165 for (k = 1; k < len; k++) {
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166
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167 if (fout[k] * fout[k] > maxVal * maxVal) {
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168 maxVal = fout[k];
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169 }
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170 }
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171 maxVal = (float) fabs(maxVal);
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172
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173 /* encoding of the maximum amplitude value */
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174
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175 if (maxVal < 10.0) {
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176 maxVal = 10.0;
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177 }
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178 maxVal = (float) log10(maxVal);
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179 sort_sq(&dtmp, idxForMax, maxVal, state_frgqTbl, 64);
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180
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181 /* decoding of the maximum amplitude representation value,
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182 and corresponding scaling of start state */
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183
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184 maxVal = state_frgqTbl[*idxForMax];
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185 qmax = (float) pow(10, maxVal);
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186 scal = (float) (4.5) / qmax;
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187 for (k = 0; k < len; k++) {
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188 fout[k] *= scal;
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189 }
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190
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191 /* predictive noise shaping encoding of scaled start state */
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192
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193 AbsQuantW(iLBCenc_inst, fout, syntDenum,
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194 weightDenum, idxVec, len, state_first);
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195 }
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