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1 // Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of "Eclipse Public License v1.0" |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // |
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15 |
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16 #include "types.h" |
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17 #include "rpeltp.h" |
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18 #include "basicop.h" |
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19 #include "tables.h" |
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20 #include "gsm610fr.h" |
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21 |
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22 /* |
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23 ** Static variables are allocated as globals in order to make it |
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24 ** possible to clear them in run time (reset codec). This might be |
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25 ** useful e.g. in possible EC code |
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26 */ |
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27 |
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28 |
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29 /* |
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30 ** void reset_encoder(CGSM610FR_Encoder* aEncoder) |
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31 ** |
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32 ** Function clears encoder variables. |
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33 ** Input: |
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34 ** None |
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35 ** Output: |
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36 ** Clear z1, L_z2, mp, LARpp_Prev[0..7], u[0..7], dp[0..119] |
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37 ** Return value: |
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38 ** None |
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39 */ |
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40 void reset_encoder(CGSM610FR_Encoder* aEncoder) |
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41 { |
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42 int i; |
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43 |
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44 aEncoder->z1 = 0; |
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45 aEncoder->L_z2 = 0; |
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46 aEncoder->mp = 0; |
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47 |
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48 for ( i = 0; i <= 7; i++ ) |
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49 aEncoder->LARpp_prev[i] = 0; |
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50 for ( i = 0; i <= 7; i++ ) |
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51 aEncoder->u[i] = 0; |
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52 for ( i = 0; i <= 119; i++ ) |
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53 aEncoder->dp[i] = 0; |
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54 } |
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55 |
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56 |
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57 /* |
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58 ** void reset_decoder(CGSM610FR_Encoder* aDecoder) |
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59 ** |
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60 ** Function clears decoder variables. |
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61 ** Input: |
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62 ** None |
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63 ** Output: |
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64 ** Clear LARpp_Prev[0..7], v[0..8], drp[0..119], nrp |
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65 ** Return value: |
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66 ** None |
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67 */ |
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68 void reset_decoder(CGSM610FR_Decoder* aDecoder) |
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69 { |
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70 int i; |
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71 |
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72 for ( i = 0; i <= 7; i++ ) |
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73 aDecoder->LARrpp_prev[i] = 0; |
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74 for ( i = 0; i <= 8; i++ ) |
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75 aDecoder->v[i] = 0; |
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76 aDecoder->msr = 0; |
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77 for ( i = 0; i <= 119; i++ ) |
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78 aDecoder->drp[i] = 0; |
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79 aDecoder->nrp = 40; |
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80 } |
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81 |
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82 /* |
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83 # 4.2.1. Downscaling of the input signal |
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84 # |
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85 # 4.2.2. Offset compensation |
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86 # |
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87 # This part implements a high-pass filter and requires extended |
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88 # arithmetic precision for the recursive part of this filter. |
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89 # |
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90 # The input of this procedure is the array so[0..159] and the output |
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91 # array sof[0..159]. |
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92 # |
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93 # Keep z1 and L_z2 in memory for the next frame. |
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94 # Initial value: z1=0; L_z2=0; |
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95 |
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96 @ Downscaling and offset compensation are combined in order to spare |
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97 @ unnecessary data moves. |
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98 */ |
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99 |
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100 void prepr( CGSM610FR_Encoder* aEncoder, int2 sof[], int2 so[] ) |
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101 { |
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102 int k; |
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103 |
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104 int2 msp; |
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105 int2 temp; |
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106 int4 L_s2; |
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107 /* |
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108 # 4.2.1. Downscaling of the input signal |
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109 # |== FOR k=0 to 159: |
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110 # | so[k] = sop[k] >> 3; |
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111 # | so[k] = so[k] << 2; |
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112 # |== NEXT k: |
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113 */ |
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114 |
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115 /* |
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116 # |== FOR k = 0 to 159: |
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117 # |Compute the non-recursive part. |
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118 # | s1 = sub( so[k], z1 ); |
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119 # | z1 = so[k]; |
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120 # |Compute the recursive part. |
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121 # | L_s2 = s1; |
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122 # | L_s2 = L_s2 << 15; |
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123 # |Execution of a 31 by 16 bits multiplication. |
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124 # | msp = L_z2 >> 15; |
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125 # | lsp = L_sub( L_z2, ( msp << 15 ) ); |
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126 # | temp = mult_r( lsp, 32735 ); |
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127 # | L_s2 = L_add( L_s2, temp ); |
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128 # | L_z2 = L_add( L_mult( msp, 32735 ) >> 1, L_s2 ); |
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129 # |Compute sof[k] with rounding. |
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130 # | sof[k] = L_add( L_z2, 16384 ) >> 15; |
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131 # |== NEXT k: |
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132 */ |
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133 for (k=0; k <= 159; k++) { |
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134 |
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135 /* Downscaling */ |
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136 temp = shl( shr( so[k], 3 ), 2 ); |
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137 |
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138 /* Compute the non-recursive part. */ |
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139 /* Compute the recursive part. */ |
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140 |
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141 L_s2 = L_deposit_l( sub( temp, aEncoder->z1 ) ); |
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142 aEncoder->z1 = temp; |
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143 |
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144 |
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145 L_s2 = L_shl( L_s2, 15 ); |
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146 /* Execution of a 31 by 16 bits multiplication. */ |
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147 msp = extract_l( L_shr( aEncoder->L_z2, 15 ) ); |
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148 temp = extract_l( L_sub( aEncoder->L_z2, L_shl( L_deposit_l( msp ), 15 ) ) ); |
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149 temp = mult_r( temp, 32735 ); |
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150 L_s2 = L_add( L_s2, L_deposit_l( temp ) ); |
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151 aEncoder->L_z2 = L_add( L_shr( L_mult( msp, 32735 ), 1 ), L_s2 ); |
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152 /* Compute sof[k] with rounding. */ |
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153 sof[k] = extract_l( L_shr( L_add( aEncoder->L_z2, (int4) 16384 ), 15 ) ); |
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154 } |
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155 } |
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156 |
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157 /* |
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158 # 4.2.3. Preemphasis |
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159 # |
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160 # Keep mp in memory for the next frame. |
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161 # Initial value: mp=0; |
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162 */ |
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163 void preemp( CGSM610FR_Encoder* aEncoder, int2 s[], int2 sof[] ) |
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164 { |
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165 int k; |
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166 int2 temp; |
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167 /* |
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168 # |== FOR k=0 to 159: |
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169 # | s[k] = add( sof[k], mult_r( mp, -28180 ) ); |
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170 # | mp = sof[k]; |
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171 # |== NEXT k: |
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172 */ |
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173 |
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174 /* |
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175 @ Reverse looping in order to make it possible to |
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176 @ update filter delay mp only at the end of the loop |
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177 */ |
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178 temp = sof[159]; /* make overwrite possible */ |
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179 |
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180 for ( k = 159; k >= 1; k-- ) |
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181 s[k] = add( sof[k], mult_r( sof[k-1], -28180 ) ); |
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182 |
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183 s[0] = add( sof[0], mult_r( aEncoder->mp, -28180 ) ); |
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184 |
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185 aEncoder->mp = temp; |
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186 } |
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187 |
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188 /* |
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189 # 4.2.4. Autocorrelation |
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190 # |
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191 # The goal is to compute the array L_ACF[k]. The signal s[i] must be |
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192 # scaled in order to avoid an overflow situation. |
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193 * |
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194 * output: |
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195 * scalauto (return value) |
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196 * |
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197 */ |
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198 int2 autoc( int4 L_ACF[], int2 s[] ) |
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199 { |
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200 int k, i; |
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201 |
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202 int2 smax; |
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203 int2 temp; |
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204 int4 L_temp2; |
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205 int2 scalauto; |
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206 /* |
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207 # Dynamic scaling of the array s[0..159]. |
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208 # |
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209 # Search for the maximum. |
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210 # |
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211 # smax=0; |
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212 # |== FOR k = 0 to 159: |
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213 # | temp = abs( s[k] ); |
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214 # | IF ( temp > smax ) THEN smax = temp; |
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215 # |== NEXT k; |
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216 */ |
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217 smax = 0; |
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218 for ( k = 0; k <= 159; k++ ) { |
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219 temp = abs_s( s[k] ); |
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220 if ( sub( temp, smax ) > 0 ) |
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221 smax = temp; |
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222 } |
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223 /* |
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224 # Computation of the scaling factor. |
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225 # |
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226 # IF ( smax == 0 ) THEN scalauto = 0; |
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227 # ELSE scalauto = sub( 4, norm( smax << 16 ) ); |
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228 */ |
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229 if ( smax == 0 ) |
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230 scalauto = 0; |
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231 else |
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232 scalauto = sub( 4, norm_l( L_deposit_h( smax ) ) ); |
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233 /* |
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234 # Scaling of the array s[0..159]. |
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235 # IF ( scalauto > 0 ) THEN |
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236 # | temp = 16384 >> sub( scalauto, 1 ); |
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237 # |== FOR k=0 to 159: |
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238 # | s[k] = mult_r( s[k], temp ); |
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239 # |== NEXT k: |
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240 */ |
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241 if ( scalauto > 0 ) { |
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242 temp = shr( 16384, sub( scalauto, 1 ) ); |
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243 for ( k = 0; k <= 159; k++ ) |
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244 s[k] = mult_r( s[k], temp ); |
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245 } |
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246 /* |
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247 # Compute the L_ACF[..]. |
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248 # |== FOR k=0 to 8: |
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249 # | L_ACF[k] = 0; |
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250 # |==== FOR i=k to 159: |
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251 # | L_temp = L_mult( s[i], s[i-k] ); |
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252 # | L_ACF[k] = L_add( L_ACF[k], L_temp ); |
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253 # |==== NEXT i: |
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254 # |== NEXT k: |
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255 */ |
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256 for ( k = 0; k <= 8; k++ ) { |
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257 L_temp2 = 0; |
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258 for ( i = k; i <= 159; i++ ) |
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259 L_temp2 = L_mac( L_temp2, s[i], s[i-k] ); |
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260 |
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261 L_ACF[k] = L_temp2; |
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262 } |
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263 /* |
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264 # Rescaling of the array s[0..159]. |
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265 # |
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266 # IF ( scalauto > 0 ) THEN |
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267 # |== FOR k = 0 to 159: |
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268 # | s[k] = s[k] << scalauto; |
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269 # |== NEXT k: |
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270 */ |
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271 if ( scalauto > 0 ) { |
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272 for ( k = 0; k <= 159; k++ ) |
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273 s[k] = shl( s[k], scalauto ); |
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274 } |
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275 return(scalauto); /* scalauto is retuned to be used also in vad */ |
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276 |
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277 } |
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278 |
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279 |
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280 /* |
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281 # 4.2.5. Computation of the reflection coefficients |
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282 */ |
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283 void schur( int2 r[], int4 L_ACF[] ) |
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284 { |
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285 int k, i, n, m; |
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286 |
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287 int2 P[9]; |
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288 int2 K[7]; |
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289 int2 ACF[9]; |
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290 int2 normacf; |
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291 |
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292 /* |
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293 # Schur recursion with 16 bits arithmetic |
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294 # |
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295 # IF ( L_ACF[0] == 0 ) THEN |
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296 # |== FOR i=1 to 8: |
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297 # | r[i] = 0; |
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298 # |== NEXT i: |
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299 # | EXIT; / continue with section 4.2.6/ |
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300 # normacf = norm( L_ACF[0] ); / temp is spec replaced with normacf / |
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301 # |== FOR k=0 to 8: |
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302 # | ACF[k] = ( L_ACF[k] << normacf ) >> 16; |
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303 # |== NEXT k: |
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304 */ |
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305 if ( L_ACF[0] == 0 ) { |
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306 for ( i = 0; i <= 7; i++) |
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307 r[i] = 0; |
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308 return; /* continue with section 4.2.6 */ |
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309 } |
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310 normacf = norm_l( L_ACF[0] ); |
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311 |
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312 for ( k = 0; k <= 8; k++ ) |
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313 ACF[k] = extract_h( L_shl( L_ACF[k], normacf ) ); |
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314 /* |
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315 # Initialize array P[..] and K[..] for the recursion. |
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316 # |
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317 # |== FOR i=1 to 7: |
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318 # | K[9-i] = ACF[i]; |
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319 # |== NEXT i: |
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320 # |
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321 # |== FOR i=0 to 8: |
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322 # | P[i] = ACF[i]; |
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323 # |== NEXT i: |
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324 */ |
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325 for ( i = 1; i <= 7; i++ ) |
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326 K[7-i] = ACF[i]; |
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327 |
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328 for ( i = 0; i <= 8; i++ ) |
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329 P[i] = ACF[i]; |
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330 /* |
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331 # Compute reflection coefficients |
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332 # |== FOR n=1 to 8: |
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333 # | IF ( P[0] < abs( P[1] ) ) THEN |
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334 # | |== FOR i=n to 8: |
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335 # | | r[i] = 0; |
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336 # | |== NEXT i: |
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337 # | | EXIT; /continue with |
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338 # | | section 4.2.6./ |
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339 # | r[n] = div( abs( P[1] ), P[0] ); |
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340 # | IF ( P[1] > 0 ) THEN r[n] = sub( 0, r[n] ); |
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341 # | |
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342 # | IF ( n == 8 ) THEN EXIT; /continue with section 4.2.6/ |
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343 # | Schur recursion |
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344 # | P[0] = add( P[0], mult_r( P[1], r[n] ) ); |
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345 # |==== FOR m=1 to 8-n: |
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346 # | P[m] = add( P[m+1], mult_r( K[9-m], r[n] ) ); |
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347 # | K[9-m] = add( K[9-m], mult_r( P[m+1], r[n] ) ); |
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348 # |==== NEXT m: |
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349 # | |
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350 # |== NEXT n: |
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351 */ |
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352 |
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353 for ( n = 0; n <= 7; n++ ) { |
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354 if ( sub( P[0], abs_s( P[1] ) ) < 0 ) { |
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355 for ( i = n; i <= 7; i++ ) |
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356 r[i] = 0; |
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357 return; /* continue with section 4.2.6. */ |
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358 } |
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359 |
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360 if ( P[1] > 0 ) |
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361 r[n] = negate( div_s( P[1], P[0] ) ); |
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362 else |
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363 r[n] = div_s( negate( P[1] ), P[0] ); |
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364 |
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365 if ( sub(int2 (n), 7) == 0 ) |
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366 return; /* continue with section 4.2.6 */ |
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367 |
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368 /* Schur recursion */ |
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369 P[0] = add( P[0], mult_r( P[1], r[n] ) ); |
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370 for ( m = 1; m <= 7-n; m++ ) { |
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371 /* |
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372 * mac_r cannot be used because it rounds the result after |
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373 * addition when add( xx, mult_r ) rounds first the result |
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374 * of the product. That is why the following two lines cannot |
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375 * be used instead of the curently used lines. |
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376 * |
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377 * P[m] = mac_r( L_deposit_l( P[m+1] ), K[7-m], r[n] ); |
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378 * K[7-m] = mac_r( L_deposit_l( K[7-m] ), P[m+1], r[n] ); |
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379 */ |
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380 P[m] = add( P[m+1], mult_r( K[7-m], r[n] ) ); |
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381 K[7-m] = add( K[7-m], mult_r( P[m+1], r[n] ) ); |
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382 } |
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383 } |
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384 } |
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385 |
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386 /* |
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387 # 4.2.6. Transformation of reflection coefficients to Log.-Area Ratios ----- |
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388 # |
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389 # The following scaling for r[..] and LAR[..] has been used: |
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390 # |
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391 # r[..] = integer( real_r[..]*32768. ); -1. <= real_r < 1. |
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392 # LAR[..] = integer( real_LAR[..]*16384. ); |
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393 # with -1.625 <= real_LAR <= 1.625 |
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394 */ |
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395 |
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396 void larcomp( int2 LAR[], int2 r[] ) |
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397 { |
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398 int i; |
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399 |
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400 int2 temp; |
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401 /* |
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402 # Computation of the LAR[1..8] from the r[1..8] |
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403 # |== FOR i=1 to 8: |
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404 # | temp = abs( r[i] ); |
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405 # | IF ( temp < 22118 ) THEN temp = temp >> 1; |
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406 # | else if ( temp < 31130 ) THEN temp = sub( temp, 11059 ); |
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407 # | else temp = sub( temp, 26112 ) << 2; |
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408 # | LAR[i] = temp; |
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409 # | IF ( r[i] < 0 ) THEN LAR[i] = sub( 0, LAR[i] ); |
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410 # |== NEXT i: |
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411 */ |
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412 for ( i = 1; i <= 8; i++ ) { |
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413 int j = i-1; |
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414 temp = abs_s( r[j] ); |
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415 |
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416 if ( sub( temp, 22118 ) < 0 ) |
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417 temp = shr( temp, 1 ); |
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418 else if ( sub( temp, 31130 ) < 0 ) |
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419 temp = sub( temp, 11059 ); |
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420 else |
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421 temp = shl( sub( temp, 26112 ), 2 ); |
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422 |
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423 if ( r[j] < 0 ) |
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424 LAR[j] = negate( temp ); |
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425 else |
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426 LAR[j] = temp; |
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427 } |
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428 } |
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429 |
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430 |
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431 /* |
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432 # 4.2.7. Quantization and coding of the Log.-Area Ratios |
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433 # |
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434 # This procedure needs fpur tables; following equations give the |
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435 # optimum scaling for the constants: |
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436 # |
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437 # A[1..8]=integer( real_A[1..8]*1024 ); 8 values (see table 4.1) |
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438 # B[1..8]=integer( real_B[1..8]*512 ); 8 values (see table 4.1) |
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439 # MAC[1..8]=maximum of the LARc[1..8]; 8 values (see table 4.1) |
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440 # MAC[1..8]=minimum of the LARc[1..8]; 8 values (see table 4.1) |
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441 */ |
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442 |
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443 void codlar( int2 LARc[], int2 LAR[] ) |
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444 { |
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445 |
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446 int i; |
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447 |
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448 int2 temp; |
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449 /* |
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450 # Computation for quantizing and coding the LAR[1..8] |
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451 # |
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452 # |== FOR i=1 to 8: |
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453 # | temp = mult( A[i], LAR[i] ); |
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454 # | temp = add( temp, B[i] ); |
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455 # | temp = add( temp, 256 ); for rounding |
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456 # | LARc[i] = temp >> 9; |
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457 # | |
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458 # | Check if LARc[i] lies between MIN and MAX |
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459 # | IF ( LARc[i] > MAC[i] ) THEN LARc[i] = MAC[i]; |
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460 # | IF ( LARc[i] < MIC[i] ) THEN LARc[i] = MIC[i]; |
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461 # | LARc[i] = sub( LARc[i], MIC[i] ); / See note below / |
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462 # |== NEXT i: |
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463 # |
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464 # NOTE: The equation is used to make all the LARc[i] positive. |
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465 */ |
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466 for ( i = 1; i <= 8; i++ ) { |
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467 int j = i-1; |
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468 temp = mult( A[j], LAR[j] ); |
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469 temp = add( temp, B[j] ); |
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470 temp = add( temp, 256 ); /* for rounding */ |
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471 temp = shr( temp, 9 ); |
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472 /* Check if LARc[i] lies between MIN and MAX */ |
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473 if ( sub( temp, MAC[j] ) > 0 ) |
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474 LARc[j] = sub( MAC[j], MIC[j] ); |
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475 else if ( sub( temp, MIC[j] ) < 0 ) |
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476 LARc[j] = 0; |
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477 else |
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478 LARc[j] = sub( temp, MIC[j] ); |
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479 } |
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480 } |
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481 |
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482 |
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483 /* |
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484 # 4.2.8 Decoding of the coded Log.-Area Ratios |
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485 # |
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486 # This procedure requires for efficient implementation two variables. |
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487 # |
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488 # INVA[1..8]=integer((32768*8)/(real_A[1..8]); 8 values (table 4.2) |
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489 # MIC[1..8]=minimum value of the LARc[1..8]; 8 values (table 4.2) |
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490 */ |
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491 |
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492 void declar( int2 LARpp[], int2 LARc[] ) |
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493 { |
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494 int i; |
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495 |
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496 int2 temp1; |
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497 int2 temp2; |
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498 /* |
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499 # Compute the LARpp[1..8]. |
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500 # |
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501 # |== FOR i=1 to 8: |
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502 # | temp1 = add( LARc[i], MIC[i] ) << 10; /See note below/ |
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503 # | temp2 = B[i] << 1; |
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504 # | temp1 = sub( temp1, temp2 ); |
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505 # | temp1 = mult_r( INVA[i], temp1 ); |
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506 # | LARpp[i] = add( temp1, temp1 ); |
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507 # |== NEXT i: |
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508 # |
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509 # NOTE: The addition of MIC[i] is used to restore the sign of LARc[i]. |
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510 */ |
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511 for ( i = 1; i <= 8; i++ ) { |
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512 int j = i-1; |
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513 temp1 = shl( add( LARc[j], MIC[j] ), 10 ); |
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514 temp2 = shl( B[j], 1 ); |
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515 temp1 = sub( temp1, temp2 ); |
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516 temp1 = mult_r( INVA[j], temp1 ); |
|
517 LARpp[j] = add( temp1, temp1 ); |
|
518 } |
|
519 } |
|
520 |
|
521 |
|
522 /* |
|
523 # 4.2.9. Computation of the quantized reflection coefficients |
|
524 # |
|
525 # Within each frame of 160 anallyzed speech samples the short term |
|
526 # analysissss and synthesis filters operate with four different sets of |
|
527 # coefficients, derived from the previous set of decoded |
|
528 # LARs(LARpp(j-1)) and the actual set of decoded LARs (LARpp(j)). |
|
529 # |
|
530 # 4.2.9.1 Interpolation of the LARpp[1..8] to get LARp[1..8] |
|
531 */ |
|
532 |
|
533 void cparc1( int2 LARp[], int2 LARpp_prev[], int2 LARpp[] ) |
|
534 { |
|
535 int i; |
|
536 |
|
537 int2 temp; |
|
538 /* |
|
539 # FOR k_start=0 to k_end = 12. |
|
540 # |
|
541 # |==== FOR i=1 to 8: |
|
542 # | LARp[i] = add( ( LARpp(j-1)[i] >> 2 ) ,( LARpp[i] >> 2 ) ); |
|
543 # | LARp[i] = add( LARp[i], ( LARpp(j-1)[i] >> 1 ) ); |
|
544 # |==== NEXT i: |
|
545 */ |
|
546 /* k_start=0 to k_end=12 */ |
|
547 |
|
548 for ( i = 1; i <= 8; i++ ) { |
|
549 int j = i-1; |
|
550 temp = add( shr( LARpp_prev[j], 2 ), shr( LARpp[j], 2 ) ); |
|
551 LARp[j] = add( temp, shr( LARpp_prev[j], 1 ) ); |
|
552 } |
|
553 } |
|
554 |
|
555 |
|
556 void cparc2( int2 LARp[], int2 LARpp_prev[], int2 LARpp[] ) |
|
557 { |
|
558 int i; |
|
559 |
|
560 /* |
|
561 # FOR k_start=13 to k_end = 26. |
|
562 # |==== FOR i=1 to 8: |
|
563 # | LARp[i] = add( ( LARpp(j-1)[i] >> 1 ), ( LARpp[i] >> 1 ) ); |
|
564 # |==== NEXT i: |
|
565 */ |
|
566 /* k_start=13 to k_end=26 */ |
|
567 |
|
568 for (i=1; i <= 8; i++) { |
|
569 int j = i-1; |
|
570 LARp[j] = add( shr( LARpp_prev[j], 1 ), shr( LARpp[j], 1 ) ); |
|
571 } |
|
572 } |
|
573 |
|
574 |
|
575 void cparc3( int2 LARp[], int2 LARpp_prev[], int2 LARpp[] ) |
|
576 { |
|
577 int i; |
|
578 |
|
579 int2 temp; |
|
580 |
|
581 /* |
|
582 # FOR k_start=27 to k_end = 39. |
|
583 # |==== FOR i=1 to 8: |
|
584 # | LARp[i] = add( ( LARpp(j-1)[i] >> 2 ), ( LARpp[i] >> 2 ) ); |
|
585 # | LARp[i] = add( LARp[i], ( LARpp[i] >> 1 ) ); |
|
586 # |==== NEXT i: |
|
587 */ |
|
588 /* k_start=27 to k_end=39 */ |
|
589 |
|
590 for ( i = 1; i <= 8; i++ ) { |
|
591 int j = i-1; |
|
592 temp = add( shr( LARpp_prev[j], 2 ), shr( LARpp[j], 2 ) ); |
|
593 LARp[j] = add( temp, shr( LARpp[j], 1 ) ); |
|
594 } |
|
595 } |
|
596 |
|
597 |
|
598 void cparc4( int2 LARp[], int2 LARpp_prev[], int2 LARpp[] ) |
|
599 { |
|
600 int i; |
|
601 |
|
602 /* |
|
603 # FOR k_start=40 to k_end = 159. |
|
604 # |==== FOR i=1 to 8: |
|
605 # | LARp[i] = LARpp[i]; |
|
606 # |==== NEXT i: |
|
607 */ |
|
608 /* k_start=40 to k_end=159 */ |
|
609 |
|
610 for ( i = 1; i <= 8; i++ ) { |
|
611 int j = i-1; |
|
612 LARp[j] = LARpp[j]; |
|
613 /* note new LARs saved here for next frame */ |
|
614 LARpp_prev[j] = LARpp[j]; |
|
615 } |
|
616 |
|
617 } |
|
618 |
|
619 |
|
620 /* |
|
621 # 4.2.9.2 Computation of the rp[] from the interpolated LARp[] |
|
622 # |
|
623 # The input of this procedure is the interpolated LARp[1..8] array. The |
|
624 # reflection coefficients, rp[i], are used in the analysis filter and in |
|
625 # the synthesis filter. |
|
626 */ |
|
627 |
|
628 void crp( int2 rp[], int2 LARp[] ) |
|
629 { |
|
630 int i; |
|
631 |
|
632 int2 temp; |
|
633 |
|
634 /* |
|
635 # |== FOR i=1 to 8: |
|
636 # | temp = abs( LARp[i] ); |
|
637 # | IF ( temp < 11059 ) THEN temp = temp << 1; |
|
638 # | ELSE IF ( temp < 20070 ) THEN temp = add( temp, 11059 ); |
|
639 # | ELSE temp = add( ( temp >> 2 ), 26112 ); |
|
640 # | rp[i] = temp; |
|
641 # | IF ( LARp[i] < 0 ) THEN rp[i] = sub( 0, rp[i] ); |
|
642 # |== NEXT i: |
|
643 */ |
|
644 for (i=1; i <= 8; i++) { |
|
645 int j = i-1; |
|
646 temp = abs_s( LARp[j] ); |
|
647 if ( sub( temp, 11059 ) < 0 ) |
|
648 temp = shl( temp, 1 ); |
|
649 else if ( sub( temp, 20070 ) < 0 ) |
|
650 temp = add( temp, 11059 ); |
|
651 else |
|
652 temp = add( shr( temp, 2 ), 26112 ); |
|
653 |
|
654 if ( LARp[j] < 0 ) |
|
655 rp[j] = negate( temp ); |
|
656 else |
|
657 rp[j] = temp; |
|
658 } |
|
659 } |
|
660 |
|
661 |
|
662 /* |
|
663 # 4.2.10. Short term analysis filtering |
|
664 # |
|
665 # This procedure computes the short term residual d[..] to be fed |
|
666 # to the RPE-LTP loop from s[..] signal and from the local rp[..] |
|
667 # array (quantized reflection coefficients). As the call of this |
|
668 # procedure can be done in many ways (see the interpolation of the LAR |
|
669 # coefficients), it is assumed that the computation begins with index |
|
670 # k_start (for arrays d[..] and s[..]) and stops with index k_end |
|
671 # (k_start and k_end are defined in 4.2.9.1): This procedure also need |
|
672 # to keep the array u[0..7] in memory for each call. |
|
673 # |
|
674 # Keep the array u[0..7] in memory. |
|
675 # Initial value: u[0..7]=0; |
|
676 */ |
|
677 |
|
678 void invfil( CGSM610FR_Encoder* aEncoder, int2 d[], int2 s[], int2 rp[], int k_start, int k_end ) |
|
679 { |
|
680 //ALEX//extern int2 u[]; |
|
681 |
|
682 int k, i; |
|
683 |
|
684 int2 temp; |
|
685 int2 sav; |
|
686 int2 di; |
|
687 /* |
|
688 # |== FOR k=k_start to k_end: |
|
689 # | di = s[k]; |
|
690 # | sav = di; |
|
691 # |==== FOR i=1 to 8: |
|
692 # | temp = add( u[i], mult_r( rp[i], di ) ); |
|
693 # | di = add( di, mult_r( rp[i], u[i] ) ); |
|
694 # | u[i] = sav; |
|
695 # | sav = temp; |
|
696 # |==== NEXT i: |
|
697 # | d[k] = di; |
|
698 # |== NEXT k: |
|
699 */ |
|
700 for ( k = k_start; k <= k_end; k++ ) { |
|
701 di = s[k]; |
|
702 sav = di; |
|
703 for ( i = 1; i <= 8; i++ ) { |
|
704 int j = i-1; |
|
705 temp = add( aEncoder->u[j], mult_r( rp[j], di ) ); |
|
706 di = add( di, mult_r( rp[j], aEncoder->u[j] ) ); |
|
707 aEncoder->u[j] = sav; |
|
708 sav = temp; |
|
709 } |
|
710 d[k] = di; |
|
711 } |
|
712 |
|
713 } |
|
714 |
|
715 |
|
716 /* |
|
717 # 4.2.11. Calculation of the LTP parameters |
|
718 # |
|
719 # This procedure computes the LTP gain (bc) and the LTP lag (Nc) for |
|
720 # the long term analysis filter. This is deone by calculating a maximum |
|
721 # of the cross-correlation function between the current sub-segment |
|
722 # short term residual signal d[0..39] (output of the short term |
|
723 # analysis filter; for each sub-segment of the RPE-LTP analysis) and the |
|
724 # previous reconstructed short term residual signal dp[-120..-1]. A |
|
725 # dynamic scaling must be performed to avoid overflow. |
|
726 # |
|
727 # Initial value: dp[-120..-1]=0; |
|
728 */ |
|
729 |
|
730 void ltpcomp( CGSM610FR_Encoder* aEncoder, int2 *Nc, int2 *bc, int2 d[], int k_start ) |
|
731 { |
|
732 int k, i; |
|
733 |
|
734 int2 lambda; |
|
735 int2 temp; |
|
736 int2 scal; |
|
737 int2 dmax; |
|
738 int4 L_max; |
|
739 int2 wt[40]; /* scaled residual, original cannot be destroyed */ |
|
740 int4 L_result; |
|
741 int4 L_power; |
|
742 int2 R; |
|
743 int2 S; |
|
744 /* |
|
745 # Search of optimum scaling of d[kstart+0..39] |
|
746 # dmax = 0; |
|
747 # |== FOR k=0 to 39: |
|
748 # | temp = abs( d[k] ); |
|
749 # | IF ( temp > dmax ) THEN dmax = temp; |
|
750 # |== NEXT k: |
|
751 */ |
|
752 dmax = 0; |
|
753 for (k=0; k <= 39; k++) { |
|
754 temp = abs_s( d[k+k_start] ); |
|
755 if ( sub( temp, dmax ) > 0 ) |
|
756 dmax = temp; |
|
757 } |
|
758 /* |
|
759 # temp = 0; |
|
760 # IF ( dmax == 0 ) THEN scal = 0; |
|
761 # ELSE temp = norm( (long)dmax << 16 ); |
|
762 # IF ( temp > 6 ) THEN scal = 0; |
|
763 # ELSE scal = sub( 6, temp ); |
|
764 */ |
|
765 temp = 0; |
|
766 if ( dmax == 0 ) |
|
767 scal = 0; |
|
768 else |
|
769 temp = norm_s( dmax ); |
|
770 |
|
771 if ( sub( temp, 6 ) > 0 ) |
|
772 scal = 0; |
|
773 else |
|
774 scal = sub( 6, temp ); /* 0 <= scal <= 6 */ |
|
775 /* |
|
776 # Initialization of a working array wt[0..39] |
|
777 # |== FOR k=0 to 39: |
|
778 # | wt[k] = d[k] >> scal; |
|
779 # |== NEXT k: |
|
780 */ |
|
781 for (k=0; k <= 39; k++) |
|
782 wt[k] = shr( d[k+k_start], scal ); /* scal >= 0 */ |
|
783 /* |
|
784 # Search for the maximum of crosscorrelation and coding of the LTP lag. |
|
785 # L_max = 0; |
|
786 # Nc = 40; |
|
787 # |
|
788 # |== FOR lambda=40 to 120: |
|
789 # | L_result = 0; |
|
790 # |==== FOR k=0 to 39: |
|
791 # | L_temp = L_mult( wt[k], dp[k-lambda] ); |
|
792 # | L_result = L_add( L_temp, L_result ); |
|
793 # |==== NEXT k: |
|
794 # | IF ( L_result > L_max ) THEN |
|
795 # | | Nc = lambda; |
|
796 # | | L_max = L_result; |
|
797 # |== NEXT lambda: |
|
798 */ |
|
799 L_max = 0; /* 32 bits maximum */ |
|
800 *Nc = 40; /* index for the maximum of cross correlation */ |
|
801 for ( lambda = 40; lambda <= 120; lambda++ ) { |
|
802 L_result = 0; |
|
803 for (k = 0; k <= 39; k++) |
|
804 L_result = L_mac( L_result, wt[k], aEncoder->dp[k-lambda+120] ); |
|
805 /* Borland C++ 3.1 Bug if -3 (386-instructions) are used. |
|
806 ** The code makes error (compared to (L_result > L_max) |
|
807 ** comparison. The problem disapears if the result of L_sub |
|
808 ** is stored to variable, e.g. |
|
809 ** if ( ( L_debug = L_sub( L_result, L_max ) ) > 0 ) { |
|
810 ** |
|
811 ** Problem does not occur when -2 option (only 286 |
|
812 ** instructions are used) |
|
813 ** |
|
814 ** The problem exist e.g. with GSM full rate test seq01.ib |
|
815 */ |
|
816 if ( L_sub( L_result, L_max ) > 0 ) { |
|
817 *Nc = lambda; |
|
818 L_max = L_result; |
|
819 } |
|
820 } |
|
821 |
|
822 /* |
|
823 # Re-scaling of L-max |
|
824 # L_max = L_max >> sub( 6, scal ); |
|
825 */ |
|
826 L_max = L_shr( L_max, sub( 6, scal ) ); |
|
827 /* |
|
828 # Initialization of a working array wt[0..39] |
|
829 # |== FOR k=0 to 39: |
|
830 # | wt[k] = dp[k-Nc] >> 3; |
|
831 # |== NEXT k: |
|
832 */ |
|
833 for (k = 0; k <= 39; k++) |
|
834 wt[k] = shr( aEncoder->dp[k - *Nc + 120], 3 ); |
|
835 /* |
|
836 # Compute the power of the reconstructed short term residual signal dp[..] |
|
837 # L_power = 0; |
|
838 # |== FOR k=0 to 39: |
|
839 # | L_temp = L_mult( wt[k], wt[k] ); |
|
840 # | L_power = L_add( L_temp, L_power ); |
|
841 # |== NEXT k: |
|
842 */ |
|
843 L_power = 0; |
|
844 for ( k = 0; k <= 39; k++ ) |
|
845 L_power = L_mac( L_power, wt[k], wt[k] ); |
|
846 /* |
|
847 # Normalization of L_max and L_power |
|
848 # IF ( L_max <= 0 ) THEN |
|
849 # | bc = 0; |
|
850 # | EXIT; /cont. with 4.2.12/ |
|
851 */ |
|
852 if ( L_max <= 0 ) { |
|
853 *bc = 0; |
|
854 return; |
|
855 } |
|
856 /* |
|
857 # IF ( L_max >= L_power ) THEN |
|
858 # | bc = 3; |
|
859 # | EXIT; /cont. with 4.2.12/ |
|
860 */ |
|
861 if ( L_sub( L_max, L_power ) >= 0 ) { |
|
862 *bc = 3; |
|
863 return; |
|
864 } |
|
865 /* |
|
866 # temp = norm( L_power ); |
|
867 # R = ( L_max << temp ) >> 16 ); |
|
868 # S = ( L_power << temp ) >> 16 ); |
|
869 */ |
|
870 temp = norm_l( L_power ); |
|
871 R = extract_h( L_shl( L_max, temp ) ); |
|
872 S = extract_h( L_shl( L_power, temp ) ); |
|
873 /* |
|
874 # Coding of the LTP gain |
|
875 # |
|
876 # Table 4.3a must be used to obtain the level DLB[i] for the |
|
877 # quantization of the LTP gain b to get the coded version bc. |
|
878 # |
|
879 # |== FOR bc=0 to 2: |
|
880 # | IF ( R <= mult( S, DLB[bc] ) ) THEN EXIT; /cont. with 4.2.12/ |
|
881 # |== NEXT bc: |
|
882 # |
|
883 # bc = 3; |
|
884 */ |
|
885 for ( i = 0; i <= 2; i++ ) { |
|
886 if ( sub( R, mult( S, DLB[i] ) ) <= 0 ) { |
|
887 *bc = int2 (i); |
|
888 return; |
|
889 } |
|
890 } |
|
891 |
|
892 *bc = 3; |
|
893 |
|
894 } |
|
895 |
|
896 |
|
897 /* |
|
898 # 4.2.12. Long term analysis filtering |
|
899 # |
|
900 # In this part, we have to decode the bc parameter to compute the |
|
901 # samples of the estimate dpp[0..39]. The decoding of bc needs the use |
|
902 # of table 4.3b. The long term residual signal e[0..39] is then |
|
903 # calculated to be fed to the RPE encoding section. |
|
904 */ |
|
905 |
|
906 void ltpfil( CGSM610FR_Encoder* aEncoder, int2 e[], int2 dpp[], int2 d[], int2 bc, int2 Nc, int k_start ) |
|
907 { |
|
908 int2 bp; |
|
909 int k; |
|
910 |
|
911 /* |
|
912 # Decoding of the coded LTP gain. |
|
913 # bp = QLB[bc]; |
|
914 */ |
|
915 bp = QLB[bc]; |
|
916 /* |
|
917 # Calculating the array e[0..39] and the array dpp[0..39] |
|
918 # |
|
919 # |== FOR k=0 to 39: |
|
920 # | dpp[k] = mult_r( bp, dp[k-Nc] ); |
|
921 # | e[k] = sub( d[k], dpp[k] ); |
|
922 # |== NEXT k: |
|
923 */ |
|
924 for ( k = 0; k <= 39; k++ ) { |
|
925 dpp[k] = mult_r( bp, aEncoder->dp[k - Nc + 120] ); |
|
926 e[k] = sub( d[k+k_start], dpp[k] ); |
|
927 } |
|
928 } |
|
929 |
|
930 |
|
931 /* |
|
932 # 4.2.13. Weighting filter |
|
933 # |
|
934 # The coefficients of teh weighting filter are stored in tables (see |
|
935 # table 4.4). The following scaling is used: |
|
936 # |
|
937 # H[0..10] = integer( real_H[0..10]*8192 ); |
|
938 */ |
|
939 |
|
940 void weight( int2 x[], int2 e[] ) |
|
941 { |
|
942 int k, i; |
|
943 |
|
944 int2 wt[50]; |
|
945 int4 L_result; |
|
946 /* |
|
947 # Initialization of a temporary working array wt[0..49] |
|
948 # |== FOR k=0 to 4: |
|
949 # | wt[k] = 0; |
|
950 # |== NEXT k: |
|
951 # |
|
952 # |== FOR k=5 to 44: |
|
953 # | wt[k] = e[k-5]; |
|
954 # |== NEXT k: |
|
955 # |
|
956 # |== FOR k=45 to 49: |
|
957 # | wt[k] = 0; |
|
958 # |== NEXT k: |
|
959 */ |
|
960 for ( k = 0; k <= 4; k++ ) |
|
961 wt[k] = 0; |
|
962 |
|
963 for ( k = 5; k <= 44; k++ ) |
|
964 wt[k] = e[k-5]; |
|
965 |
|
966 for ( k = 45; k <= 49; k++ ) |
|
967 wt[k] = 0; |
|
968 /* |
|
969 # Compute the signal x[0..39] |
|
970 # |== FOR k=0 to 39: |
|
971 # | L_result = 8192; |
|
972 # |==== FOR i=0 to 10: |
|
973 # | L_temp = L_mult( wt[k+i], H[i] ); |
|
974 # | L_result = L_add( L_result, L_temp ); |
|
975 # |==== NEXT i: |
|
976 # | L_result = L_add( L_result, L_result ); /scaling L_result (x2)/ |
|
977 # | L_result = L_add( L_result, L_result ); /scaling L_result (x4)/ |
|
978 # | x[k] = (int)( L_result >> 16 ); |
|
979 # |== NEXT k: |
|
980 */ |
|
981 for ( k = 0; k <= 39; k++ ) { |
|
982 L_result = L_deposit_l( 8192 ); |
|
983 for ( i = 0; i <= 10; i++ ) |
|
984 L_result = L_mac( L_result, wt[k+i], H[i] ); |
|
985 |
|
986 /* scaling L_result (x4) and extract: scaling possible with new shift |
|
987 * because saturation is added L_shl |
|
988 * |
|
989 * L_result = L_add( L_result, L_result ); |
|
990 * L_result = L_add( L_result, L_result ); |
|
991 * x[k] = extract_h( L_result ); |
|
992 @ Scaling can be done with L_shift because now shift has saturation |
|
993 */ |
|
994 |
|
995 x[k] = extract_h( L_shl( L_result, 2 ) ); |
|
996 } |
|
997 } |
|
998 |
|
999 |
|
1000 /* |
|
1001 # 4.2.14. RPE grid selection |
|
1002 # |
|
1003 # The signal x[0..39] is used to select the RPE grid which is |
|
1004 # represented by Mc. |
|
1005 */ |
|
1006 |
|
1007 int2 gridsel( int2 xM[], int2 x[] ) |
|
1008 { |
|
1009 int i, k; |
|
1010 |
|
1011 int2 temp1; |
|
1012 int4 L_EM; |
|
1013 int4 L_result; |
|
1014 int2 Mc; |
|
1015 /* |
|
1016 # EM = 0; |
|
1017 # Mc = 0; |
|
1018 */ |
|
1019 L_EM = 0; |
|
1020 Mc = 0; |
|
1021 /* |
|
1022 # |== FOR m=0 to 3: |
|
1023 # | L_result = 0; |
|
1024 # |==== FOR k=0 to 12: |
|
1025 # | temp1 = x[i+(3*k)] >> 2; |
|
1026 # | L_temp = L_mult( temp1, temp1 ); |
|
1027 # | L_result = L_add( L_temp, L_result ); |
|
1028 # |==== NEXT i: |
|
1029 # | IF ( L_result > L_max ) THEN |
|
1030 # | | Mc = m; |
|
1031 # | | EM = L_result; |
|
1032 # |== NEXT m: |
|
1033 */ |
|
1034 for ( i = 0; i <= 3; i++ ) { |
|
1035 L_result = 0; |
|
1036 for ( k = 0; k <= 12; k++ ) { |
|
1037 temp1 = shr( x[i+(3*k)], 2 ); |
|
1038 L_result = L_mac( L_result, temp1, temp1 ); |
|
1039 } |
|
1040 if ( L_sub( L_result, L_EM ) > 0 ) { |
|
1041 Mc = int2 (i); |
|
1042 L_EM = L_result; |
|
1043 } |
|
1044 } |
|
1045 /* |
|
1046 # Down-sampling by factor 3 to get the selected xM[0..12] RPE sequence |
|
1047 # |== FOR i=0 to 12: |
|
1048 # | xM[k] = x[Mc+(3*i)]; |
|
1049 # |== NEXT i: |
|
1050 */ |
|
1051 for ( k = 0; k <= 12; k++ ) |
|
1052 xM[k] = x[Mc+(3*k)]; |
|
1053 |
|
1054 return Mc; |
|
1055 } |
|
1056 |
|
1057 |
|
1058 /* |
|
1059 # Compute exponent and mantissa of the decoded version of xmaxc |
|
1060 # |
|
1061 # Part of APCM and (subrogram apcm() InvAPCM (iapcm()) |
|
1062 */ |
|
1063 |
|
1064 void expman( int2 *Exp, int2 *mant, int2 xmaxc ) |
|
1065 { |
|
1066 int i; |
|
1067 /* |
|
1068 # Compute exponent and mantissa of the decoded version of xmaxc. |
|
1069 # |
|
1070 # exp = 0; |
|
1071 # IF ( xmaxc > 15 ) THEN exp = sub( ( xmaxc >> 3 ), 1 ); |
|
1072 # mant = sub( xmaxc, ( exp << 3 ) ); |
|
1073 */ |
|
1074 *Exp = 0; |
|
1075 if ( sub( xmaxc, 15 ) > 0 ) |
|
1076 *Exp = sub( shr( xmaxc, 3 ), 1 ); |
|
1077 |
|
1078 *mant = sub( xmaxc, shl( *Exp, 3 ) ); |
|
1079 /* |
|
1080 # Normalize mantissa 0 <= mant <= 7. |
|
1081 # IF ( mant == 0 ) THEN | exp = -4; |
|
1082 # | mant = 15 ; |
|
1083 # ELSE | itest = 0; |
|
1084 # |== FOR i=0 to 2: |
|
1085 # | IF ( mant > 7 ) THEN itest = 1; |
|
1086 # | IF ( itest == 0 ) THEN mant = add( ( mant << 1 ), 1 ); |
|
1087 # | IF ( itest == 0 ) THEN exp = sub( exp, 1 ); |
|
1088 # |== NEXT i: |
|
1089 */ |
|
1090 if ( *mant == 0 ) { |
|
1091 *Exp = -4; |
|
1092 *mant = 15 ; |
|
1093 } |
|
1094 else { |
|
1095 for ( i = 0; i <= 2; i++ ) { |
|
1096 if ( sub( *mant, 7 ) > 0 ) |
|
1097 break; |
|
1098 else { |
|
1099 *mant = add( shl( *mant, 1 ), 1 ); |
|
1100 *Exp = sub( *Exp, 1 ); |
|
1101 } |
|
1102 } |
|
1103 } |
|
1104 /* |
|
1105 # mant = sub( mant, 8 ); |
|
1106 */ |
|
1107 *mant = sub( *mant, 8 ); |
|
1108 } |
|
1109 |
|
1110 |
|
1111 int2 quantize_xmax( int2 xmax ) |
|
1112 { |
|
1113 int i; |
|
1114 |
|
1115 int2 Exp; |
|
1116 int2 temp; |
|
1117 int2 itest; |
|
1118 /* |
|
1119 # Quantizing and coding of xmax to get xmaxc. |
|
1120 # exp = 0; |
|
1121 # temp = xmax >> 9; |
|
1122 # itest = 0; |
|
1123 # |== FOR i=0 to 5: |
|
1124 # | IF ( temp <= 0 ) THEN itest = 1; |
|
1125 # | temp = temp >> 1; |
|
1126 # | IF ( itest == 0 ) THEN exp = add( exp, 1 ) ; |
|
1127 # |== NEXT i: |
|
1128 */ |
|
1129 Exp = 0; |
|
1130 temp = shr( xmax, 9 ); |
|
1131 itest = 0; |
|
1132 for ( i = 0; i <= 5; i++ ) { |
|
1133 if ( temp <= 0 ) |
|
1134 itest = 1; |
|
1135 temp = shr( temp, 1 ); |
|
1136 if ( itest == 0 ) |
|
1137 Exp = add( Exp, 1 ) ; |
|
1138 } |
|
1139 |
|
1140 /* |
|
1141 # temp = add( exp, 5 ); |
|
1142 # xmaxc = add( ( xmax >> temp ), ( exp << 3 ) ); |
|
1143 */ |
|
1144 temp = add( Exp, 5 ); |
|
1145 |
|
1146 return ( add( shr( xmax, temp ), shl( Exp, 3 ) ) ); /* xmaxc */ |
|
1147 |
|
1148 } |
|
1149 |
|
1150 |
|
1151 /* |
|
1152 # 4.2.15. APCM quantization of the selected RPE sequence |
|
1153 # |
|
1154 # Keep in memory exp and mant for the following inverse APCM quantizer. |
|
1155 * |
|
1156 * return unquantzed xmax for SID computation |
|
1157 */ |
|
1158 |
|
1159 int2 apcm( int2 *xmaxc, int2 xM[], int2 xMc[], int2 *Exp, int2 *mant ) |
|
1160 { |
|
1161 int k; |
|
1162 |
|
1163 int2 temp; |
|
1164 int2 temp1; |
|
1165 int2 temp2; |
|
1166 int2 temp3; |
|
1167 int2 xmax; |
|
1168 /* |
|
1169 # Find the maximum absolute value of xM[0..12]. |
|
1170 # xmax = 0; |
|
1171 # |== FOR k=0 to 12: |
|
1172 # | temp = abs( xM[k] ); |
|
1173 # | IF ( temp > xmax ) THEN xmax = temp; |
|
1174 # |== NEXT i: |
|
1175 */ |
|
1176 xmax = 0; |
|
1177 for ( k = 0; k <= 12; k++ ) { |
|
1178 temp = abs_s( xM[k] ); |
|
1179 if ( sub( temp, xmax ) > 0 ) |
|
1180 xmax = temp; |
|
1181 } |
|
1182 |
|
1183 /* |
|
1184 * quantization of xmax moved to function because it is used |
|
1185 * also in comfort noise generation |
|
1186 */ |
|
1187 *xmaxc = quantize_xmax( xmax ); |
|
1188 |
|
1189 expman( Exp, mant, *xmaxc ); /* compute exp. and mant. */ |
|
1190 /* |
|
1191 # Quantizing and coding of the xM[0..12] RPE sequence to get the xMc[0..12] |
|
1192 # |
|
1193 # This computation uses the fact that the decoded version of xmaxc can |
|
1194 # be calculated by using the exponent and mantissa part of xmaxc |
|
1195 # (logarithmic table). |
|
1196 # |
|
1197 # So, this method avoids any division and uses only scaling of the RPE |
|
1198 # samples by a function of the exponent. A direct multiplication by the |
|
1199 # inverse of the mantissa (NRFAC[0..7] found in table 4.5) gives the 3 |
|
1200 # bit coded version xMc[0..12} of the RPE samples. |
|
1201 # |
|
1202 # Direct computation of xMc[0..12] using table 4.5. |
|
1203 # temp1 = sub( 6, exp ); /normalization by the exponent/ |
|
1204 # temp2 = NRFAC[mant]; /see table 4.5 (inverse mantissa)/ |
|
1205 # |== FOR k=0 to 12: |
|
1206 # | xM[k] = xM[k] << temp1; |
|
1207 # | xM[k] = mult( xM[k], temp2 ); |
|
1208 # | xMc[k] = add( ( xM[k] >> 12 ), 4 ); / See note below/ |
|
1209 # |== NEXT i: |
|
1210 # |
|
1211 # NOTE: This equation is used to make all the xMx[i] positive. |
|
1212 */ |
|
1213 temp1 = sub( 6, *Exp ); |
|
1214 temp2 = NRFAC[*mant]; |
|
1215 |
|
1216 for ( k = 0; k <= 12; k++ ) { |
|
1217 temp3 = shl( xM[k], temp1 ); |
|
1218 temp3 = mult( temp3, temp2 ); |
|
1219 xMc[k] = add( shr( temp3, 12 ), 4 ); |
|
1220 } |
|
1221 |
|
1222 return xmax; |
|
1223 } |
|
1224 |
|
1225 /* |
|
1226 # 4.2.16. APCM inverse quantization |
|
1227 # |
|
1228 # This part is for decoding the RPE sequence of coded xMc[0..12] samples |
|
1229 # to obtain the xMp[0..12] array. Table 4.6 is used to get the mantissa |
|
1230 # of xmaxc (FAC[0..7]). |
|
1231 */ |
|
1232 |
|
1233 void iapcm( int2 xMp[], int2 xMc[], int2 Exp, int2 mant ) |
|
1234 { |
|
1235 //ALEX//extern int2 FAC[]; |
|
1236 |
|
1237 int k; |
|
1238 |
|
1239 int2 temp; |
|
1240 int2 temp1; |
|
1241 int2 temp2; |
|
1242 int2 temp3; |
|
1243 /* |
|
1244 # temp1 = FAC[mant]; /See 4.2.15 for mant/ |
|
1245 # temp2 = sub( 6, exp ); /See 4.2.15 for exp/ |
|
1246 # temp3 = 1 << sub( temp2, 1 ); |
|
1247 */ |
|
1248 temp1 = FAC[mant]; |
|
1249 temp2 = sub( 6, Exp ); |
|
1250 temp3 = shl( 1, sub( temp2, 1 ) ); |
|
1251 /* |
|
1252 # |== FOR k=0 to 12: |
|
1253 # | temp = sub( ( xMc[k] << 1 ), 7 ); /See note below/ |
|
1254 # | temp = temp << 12; |
|
1255 # | temp = mult_r( temp1, temp ); |
|
1256 # | temp = add( temp, temp3 ); |
|
1257 # | xMp[k] = temp >> temp2; |
|
1258 # |== NEXT i: |
|
1259 # |
|
1260 # NOTE: This subtraction is used to restore the sign of xMc[i]. |
|
1261 */ |
|
1262 for ( k = 0; k <= 12; k++ ) { |
|
1263 temp = sub( shl( xMc[k], 1 ), 7 ); |
|
1264 temp = shl( temp, 12 ); |
|
1265 temp = mult_r( temp1, temp ); |
|
1266 temp = add( temp, temp3 ); |
|
1267 xMp[k] = shr( temp, temp2 ); |
|
1268 } |
|
1269 } |
|
1270 |
|
1271 /* |
|
1272 # 4.2.17. RPE grid positioning |
|
1273 # |
|
1274 # This procedure computes the reconstructed long term residual signal |
|
1275 # ep[0..39] for the LTP analysis filter. The inputs are the Mc which is |
|
1276 # the grid position selection and the xMp[0..12] decoded RPE samples |
|
1277 # which are upsampled by factor of 3 by inserting zero values. |
|
1278 */ |
|
1279 |
|
1280 void gridpos( int2 ep[], int2 xMp[], int2 Mc ) |
|
1281 { |
|
1282 int k; |
|
1283 /* |
|
1284 # |== FOR k=0 to 39: |
|
1285 # | ep[k] = 0; |
|
1286 # |== NEXT k: |
|
1287 */ |
|
1288 for ( k = 0; k <= 39; k++ ) |
|
1289 ep[k] = 0; |
|
1290 /* |
|
1291 # |== FOR i=0 to 12: |
|
1292 # | ep[Mc + (3*k)] = xMp[k]; |
|
1293 # |== NEXT i: |
|
1294 */ |
|
1295 for ( k = 0; k <= 12; k++ ) |
|
1296 ep[Mc + (3*k)] = xMp[k]; |
|
1297 } |
|
1298 |
|
1299 |
|
1300 /* |
|
1301 # 4.2.18. Update of the reconstructed short term residual signal dp[] |
|
1302 # |
|
1303 # Keep the array dp[-120..-1] in memory for the next sub-segment. |
|
1304 # Initial value: dp[-120..-1]=0; |
|
1305 */ |
|
1306 |
|
1307 void ltpupd( CGSM610FR_Encoder* aEncoder, int2 dpp[], int2 ep[] ) |
|
1308 { |
|
1309 int i; |
|
1310 /* |
|
1311 # |== FOR k=0 to 79: |
|
1312 # | dp[-120+k] = dp[-80+k]; |
|
1313 # |== NEXT k: |
|
1314 */ |
|
1315 for (i = 0; i <= 79; i++) |
|
1316 aEncoder->dp[-120+i+120] = aEncoder->dp[-80+i+120]; |
|
1317 /* |
|
1318 # |== FOR k=0 to 39: |
|
1319 # | dp[-40+k] = add( ep[k], dpp[k] ); |
|
1320 # |== NEXT k: |
|
1321 */ |
|
1322 for (i = 0; i <= 39; i++) |
|
1323 aEncoder->dp[-40+i+120] = add( ep[i], dpp[i] ); |
|
1324 } |
|
1325 |
|
1326 |
|
1327 /* |
|
1328 # 4.3.2. Long term synthesis filtering |
|
1329 # |
|
1330 # Keep the nrp value for the next sub-segment. |
|
1331 # Initial value: nrp=40; |
|
1332 # |
|
1333 # Keep the array drp[-120..-1] for the next sub-segment. |
|
1334 # Initial value: drp[-120..-1]=0; |
|
1335 */ |
|
1336 |
|
1337 void ltpsyn( CGSM610FR_Decoder* aDecoder, int2 erp[], int2 wt[], int2 bcr, int2 Ncr ) |
|
1338 { |
|
1339 int k, i; |
|
1340 |
|
1341 int2 drpp; |
|
1342 int2 Nr; |
|
1343 int2 brp; |
|
1344 /* |
|
1345 # Check the limits of Nr |
|
1346 # Nr = Ncr; |
|
1347 # IF ( Ncr < 40 ) THEN Nr = nrp; |
|
1348 # IF ( Ncr > 120 ) THEN Nr = nrp; |
|
1349 # nrp = Nr; |
|
1350 */ |
|
1351 if ( sub( Ncr, 40 ) < 0 ) |
|
1352 Nr = aDecoder->nrp; |
|
1353 else if ( sub( Ncr, 120 ) > 0 ) |
|
1354 Nr = aDecoder->nrp; |
|
1355 else |
|
1356 Nr = Ncr; |
|
1357 |
|
1358 aDecoder->nrp = Nr; |
|
1359 |
|
1360 /* |
|
1361 # Decoding of the LTP gain bcr. |
|
1362 # brp = QLB[bcr]; |
|
1363 */ |
|
1364 brp = QLB[bcr]; |
|
1365 /* |
|
1366 # Computation of the reconstructed short term residual signal drp[0..39]. |
|
1367 # |== FOR k=0 to 39: |
|
1368 # | drpp = mult_r( brp, drp[k-Nr] ); |
|
1369 # | drp[k+120] = add( erp[k], drpp ); |
|
1370 # |== NEXT k: |
|
1371 */ |
|
1372 for ( k = 0; k <= 39; k++ ) { |
|
1373 drpp = mult_r( brp, aDecoder->drp[k-Nr+120] ); |
|
1374 wt[k] = add( erp[k], drpp ); |
|
1375 } |
|
1376 /* |
|
1377 # Update of the reconstructed short term residual signal drp[-1..-120] |
|
1378 # |== FOR k=0 to 119: |
|
1379 # | drp[-120+k] = drp[-80+k]; |
|
1380 # |== NEXT k: |
|
1381 */ |
|
1382 |
|
1383 for ( i = 0; i < 80; i++ ) |
|
1384 aDecoder->drp[i] = aDecoder->drp[40+i]; |
|
1385 |
|
1386 for ( i = 0; i < 40; i++ ) |
|
1387 aDecoder->drp[i+80] = wt[i]; |
|
1388 } |
|
1389 |
|
1390 |
|
1391 /* |
|
1392 # 4.3.4. Short term synthesis filtering section |
|
1393 # |
|
1394 # This procedure uses the drp[0..39] signal and produces the sr[0..159] |
|
1395 # signal which is the output of the short term synthesis filter. For |
|
1396 # ease of explanation, a temporary array wt[0..159] is used. |
|
1397 # |
|
1398 # Initialization of the array wt[0..159]. |
|
1399 # |
|
1400 # For the first sub-segment in a frame: |
|
1401 # |== FOR k=0 to 39: |
|
1402 # | wt[k] = drp[k]; |
|
1403 # |== NEXT k: |
|
1404 # |
|
1405 # For the second sub-segment in a frame: |
|
1406 # |== FOR k=0 to 39: |
|
1407 # | wt[40+k] = drp[k]; |
|
1408 # |== NEXT k: |
|
1409 # |
|
1410 # For the third sub-segment in a frame: |
|
1411 # |== FOR k=0 to 39: |
|
1412 # | wt[80+k] = drp[k]; |
|
1413 # |== NEXT k: |
|
1414 # |
|
1415 # For the fourth sub-segment in a frame: |
|
1416 # |== FOR k=0 to 39: |
|
1417 # | wt[120+k] = drp[k]; |
|
1418 # |== NEXT k: |
|
1419 # |
|
1420 # As the call of the short term synthesis filter procedure can be done |
|
1421 # in many ways (see the interpolation of the LAR coefficient), it is |
|
1422 # assumed that the computation begins with index k_start (for arrays |
|
1423 # wt[..] and sr[..]) and stops with index k_end (k_start and k_end are |
|
1424 # defined in 4.2.9.1). The procedure also needs to keep the array |
|
1425 # v[0..8] in memory between calls. |
|
1426 # |
|
1427 # Keep the array v[0..8] in memory for the next call. |
|
1428 # Initial value: v[0..8]=0; |
|
1429 */ |
|
1430 |
|
1431 void synfil( CGSM610FR_Decoder* aDecoder, int2 sr[], int2 wt[], int2 rrp[], int k_start, int k_end ) |
|
1432 { |
|
1433 int k; |
|
1434 int i; |
|
1435 |
|
1436 int2 sri; |
|
1437 /* |
|
1438 # |== FOR k=k_start to k_end: |
|
1439 # | sri = wt[k]; |
|
1440 # |==== FOR i=1 to 8: |
|
1441 # | sri = sub( sri, mult_r( rrp[9-i], v[8-i] ) ); |
|
1442 # | v[9-i] = add( v[8-i], mult_r( rrp[9-i], sri ) ) ; |
|
1443 # |==== NEXT i: |
|
1444 # | sr[k] = sri; |
|
1445 # | v[0] = sri; |
|
1446 # |== NEXT k: |
|
1447 */ |
|
1448 for ( k = k_start; k <= k_end; k++ ) { |
|
1449 sri = wt[k]; |
|
1450 for ( i = 1; i <= 8; i++ ) { |
|
1451 int j = i+1; |
|
1452 sri = sub( sri, mult_r( rrp[9-j], aDecoder->v[8-i] ) ); |
|
1453 aDecoder->v[9-i] = add( aDecoder->v[8-i], mult_r( rrp[9-j], sri ) ) ; |
|
1454 } |
|
1455 sr[k] = sri; |
|
1456 aDecoder->v[0] = sri; |
|
1457 } |
|
1458 |
|
1459 } |
|
1460 |
|
1461 |
|
1462 /* |
|
1463 ** 4.3.5., 4.3.6., 4.3.7. Postprocessing |
|
1464 ** |
|
1465 ** Combined deemphasis, upscaling and truncation |
|
1466 */ |
|
1467 void postpr( CGSM610FR_Decoder* aDecoder, int2 srop[], int2 sr[] ) |
|
1468 { |
|
1469 int k; |
|
1470 /* |
|
1471 # 4.3.5. Deemphasis filtering |
|
1472 # |
|
1473 # Keep msr in memory for the next frame. |
|
1474 # Initial value: msr=0; |
|
1475 */ |
|
1476 /* |
|
1477 # |== FOR k=0 to 159: |
|
1478 # | temp = add( sr[k], mult_r( msr, 28180 ) ); |
|
1479 # | msr = temp; |
|
1480 # | sro[k] = msr; |
|
1481 # |== NEXT k: |
|
1482 */ |
|
1483 /* |
|
1484 # 4.3.6 Upscaling of the output signal |
|
1485 */ |
|
1486 /* |
|
1487 # |== FOR k=0 to 159: |
|
1488 # | srop[k] = add( sro[k], sro[k] ); |
|
1489 # |== NEXT k: |
|
1490 */ |
|
1491 /* |
|
1492 # 4.3.7. Truncation of the output variable |
|
1493 */ |
|
1494 /* |
|
1495 # |== FOR k=0 to 159: |
|
1496 # | srop[k] = srop[k] >> 3; |
|
1497 # | srop[k] = srop[k] << 3; |
|
1498 # |== NEXT k: |
|
1499 */ |
|
1500 |
|
1501 for ( k = 0; k <= 159; k++ ) { |
|
1502 aDecoder->msr = add( sr[k], mult_r( aDecoder->msr, 28180 ) ); |
|
1503 srop[k] = int2 (shl( aDecoder->msr, 1 ) & 0xfff8); |
|
1504 } |
|
1505 } |
|
1506 |