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Rev | Author | Line No. | Line |
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1905 | serge | 1 | /* |
2 | dct64.c: DCT64, the plain C version |
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3 | |||
4 | copyright ?-2006 by the mpg123 project - free software under the terms of the LGPL 2.1 |
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5 | see COPYING and AUTHORS files in distribution or http://mpg123.org |
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6 | initially written by Michael Hipp |
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7 | */ |
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8 | |||
9 | /* |
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10 | * Discrete Cosine Tansform (DCT) for subband synthesis |
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11 | * |
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12 | * -funroll-loops (for gcc) will remove the loops for better performance |
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13 | * using loops in the source-code enhances readabillity |
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14 | * |
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15 | * |
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16 | * TODO: write an optimized version for the down-sampling modes |
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17 | * (in these modes the bands 16-31 (2:1) or 8-31 (4:1) are zero |
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18 | */ |
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19 | |||
20 | #include "mpg123lib_intern.h" |
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21 | |||
22 | void dct64(real *out0,real *out1,real *samples) |
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23 | { |
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24 | real bufs[64]; |
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25 | |||
26 | { |
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27 | register int i,j; |
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28 | register real *b1,*b2,*bs,*costab; |
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29 | |||
30 | b1 = samples; |
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31 | bs = bufs; |
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32 | costab = pnts[0]+16; |
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33 | b2 = b1 + 32; |
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34 | |||
35 | for(i=15;i>=0;i--) |
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36 | *bs++ = (*b1++ + *--b2); |
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37 | for(i=15;i>=0;i--) |
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38 | *bs++ = REAL_MUL((*--b2 - *b1++), *--costab); |
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39 | |||
40 | b1 = bufs; |
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41 | costab = pnts[1]+8; |
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42 | b2 = b1 + 16; |
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43 | |||
44 | { |
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45 | for(i=7;i>=0;i--) |
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46 | *bs++ = (*b1++ + *--b2); |
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47 | for(i=7;i>=0;i--) |
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48 | *bs++ = REAL_MUL((*--b2 - *b1++), *--costab); |
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49 | b2 += 32; |
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50 | costab += 8; |
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51 | for(i=7;i>=0;i--) |
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52 | *bs++ = (*b1++ + *--b2); |
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53 | for(i=7;i>=0;i--) |
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54 | *bs++ = REAL_MUL((*b1++ - *--b2), *--costab); |
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55 | b2 += 32; |
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56 | } |
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57 | |||
58 | bs = bufs; |
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59 | costab = pnts[2]; |
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60 | b2 = b1 + 8; |
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61 | |||
62 | for(j=2;j;j--) |
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63 | { |
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64 | for(i=3;i>=0;i--) |
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65 | *bs++ = (*b1++ + *--b2); |
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66 | for(i=3;i>=0;i--) |
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67 | *bs++ = REAL_MUL((*--b2 - *b1++), costab[i]); |
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68 | b2 += 16; |
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69 | for(i=3;i>=0;i--) |
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70 | *bs++ = (*b1++ + *--b2); |
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71 | for(i=3;i>=0;i--) |
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72 | *bs++ = REAL_MUL((*b1++ - *--b2), costab[i]); |
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73 | b2 += 16; |
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74 | } |
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75 | |||
76 | b1 = bufs; |
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77 | costab = pnts[3]; |
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78 | b2 = b1 + 4; |
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79 | |||
80 | for(j=4;j;j--) |
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81 | { |
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82 | *bs++ = (*b1++ + *--b2); |
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83 | *bs++ = (*b1++ + *--b2); |
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84 | *bs++ = REAL_MUL((*--b2 - *b1++), costab[1]); |
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85 | *bs++ = REAL_MUL((*--b2 - *b1++), costab[0]); |
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86 | b2 += 8; |
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87 | *bs++ = (*b1++ + *--b2); |
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88 | *bs++ = (*b1++ + *--b2); |
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89 | *bs++ = REAL_MUL((*b1++ - *--b2), costab[1]); |
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90 | *bs++ = REAL_MUL((*b1++ - *--b2), costab[0]); |
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91 | b2 += 8; |
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92 | } |
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93 | bs = bufs; |
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94 | costab = pnts[4]; |
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95 | |||
96 | for(j=8;j;j--) |
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97 | { |
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98 | real v0,v1; |
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99 | v0=*b1++; v1 = *b1++; |
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100 | *bs++ = (v0 + v1); |
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101 | *bs++ = REAL_MUL((v0 - v1), (*costab)); |
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102 | v0=*b1++; v1 = *b1++; |
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103 | *bs++ = (v0 + v1); |
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104 | *bs++ = REAL_MUL((v1 - v0), (*costab)); |
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105 | } |
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106 | |||
107 | } |
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108 | |||
109 | |||
110 | { |
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111 | register real *b1; |
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112 | register int i; |
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113 | |||
114 | for(b1=bufs,i=8;i;i--,b1+=4) |
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115 | b1[2] += b1[3]; |
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116 | |||
117 | for(b1=bufs,i=4;i;i--,b1+=8) |
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118 | { |
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119 | b1[4] += b1[6]; |
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120 | b1[6] += b1[5]; |
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121 | b1[5] += b1[7]; |
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122 | } |
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123 | |||
124 | for(b1=bufs,i=2;i;i--,b1+=16) |
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125 | { |
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126 | b1[8] += b1[12]; |
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127 | b1[12] += b1[10]; |
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128 | b1[10] += b1[14]; |
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129 | b1[14] += b1[9]; |
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130 | b1[9] += b1[13]; |
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131 | b1[13] += b1[11]; |
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132 | b1[11] += b1[15]; |
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133 | } |
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134 | } |
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135 | |||
136 | |||
137 | out0[0x10*16] = REAL_SCALE_DCT64(bufs[0]); |
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138 | out0[0x10*15] = REAL_SCALE_DCT64(bufs[16+0] + bufs[16+8]); |
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139 | out0[0x10*14] = REAL_SCALE_DCT64(bufs[8]); |
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140 | out0[0x10*13] = REAL_SCALE_DCT64(bufs[16+8] + bufs[16+4]); |
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141 | out0[0x10*12] = REAL_SCALE_DCT64(bufs[4]); |
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142 | out0[0x10*11] = REAL_SCALE_DCT64(bufs[16+4] + bufs[16+12]); |
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143 | out0[0x10*10] = REAL_SCALE_DCT64(bufs[12]); |
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144 | out0[0x10* 9] = REAL_SCALE_DCT64(bufs[16+12] + bufs[16+2]); |
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145 | out0[0x10* 8] = REAL_SCALE_DCT64(bufs[2]); |
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146 | out0[0x10* 7] = REAL_SCALE_DCT64(bufs[16+2] + bufs[16+10]); |
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147 | out0[0x10* 6] = REAL_SCALE_DCT64(bufs[10]); |
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148 | out0[0x10* 5] = REAL_SCALE_DCT64(bufs[16+10] + bufs[16+6]); |
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149 | out0[0x10* 4] = REAL_SCALE_DCT64(bufs[6]); |
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150 | out0[0x10* 3] = REAL_SCALE_DCT64(bufs[16+6] + bufs[16+14]); |
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151 | out0[0x10* 2] = REAL_SCALE_DCT64(bufs[14]); |
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152 | out0[0x10* 1] = REAL_SCALE_DCT64(bufs[16+14] + bufs[16+1]); |
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153 | out0[0x10* 0] = REAL_SCALE_DCT64(bufs[1]); |
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154 | |||
155 | out1[0x10* 0] = REAL_SCALE_DCT64(bufs[1]); |
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156 | out1[0x10* 1] = REAL_SCALE_DCT64(bufs[16+1] + bufs[16+9]); |
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157 | out1[0x10* 2] = REAL_SCALE_DCT64(bufs[9]); |
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158 | out1[0x10* 3] = REAL_SCALE_DCT64(bufs[16+9] + bufs[16+5]); |
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159 | out1[0x10* 4] = REAL_SCALE_DCT64(bufs[5]); |
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160 | out1[0x10* 5] = REAL_SCALE_DCT64(bufs[16+5] + bufs[16+13]); |
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161 | out1[0x10* 6] = REAL_SCALE_DCT64(bufs[13]); |
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162 | out1[0x10* 7] = REAL_SCALE_DCT64(bufs[16+13] + bufs[16+3]); |
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163 | out1[0x10* 8] = REAL_SCALE_DCT64(bufs[3]); |
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164 | out1[0x10* 9] = REAL_SCALE_DCT64(bufs[16+3] + bufs[16+11]); |
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165 | out1[0x10*10] = REAL_SCALE_DCT64(bufs[11]); |
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166 | out1[0x10*11] = REAL_SCALE_DCT64(bufs[16+11] + bufs[16+7]); |
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167 | out1[0x10*12] = REAL_SCALE_DCT64(bufs[7]); |
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168 | out1[0x10*13] = REAL_SCALE_DCT64(bufs[16+7] + bufs[16+15]); |
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169 | out1[0x10*14] = REAL_SCALE_DCT64(bufs[15]); |
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170 | out1[0x10*15] = REAL_SCALE_DCT64(bufs[16+15]); |
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171 | |||
172 | } |
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173 |