## ffmpeg / libavcodec / faandct.c @ bc0219fd

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1 | 65e4c8c9 | Michael Niedermayer | ```
/*
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2 | ```
* Floating point AAN DCT
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3 | ```
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
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4 | ```
*
``` |
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5 | ```
* This library is free software; you can redistribute it and/or
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6 | ```
* modify it under the terms of the GNU Lesser General Public
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7 | ```
* License as published by the Free Software Foundation; either
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8 | ```
* version 2 of the License, or (at your option) any later version.
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9 | ```
*
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10 | ```
* This library is distributed in the hope that it will be useful,
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11 | ```
* but WITHOUT ANY WARRANTY; without even the implied warranty of
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12 | ```
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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13 | ```
* Lesser General Public License for more details.
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14 | ```
*
``` |
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15 | ```
* You should have received a copy of the GNU Lesser General Public
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16 | ```
* License along with this library; if not, write to the Free Software
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17 | ```
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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18 | ```
*
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19 | 6f5cf8c5 | Michael Niedermayer | ```
* this implementation is based upon the IJG integer AAN DCT (see jfdctfst.c)
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20 | 65e4c8c9 | Michael Niedermayer | ```
*/
``` |

21 | |||

22 | ```
/**
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23 | ```
* @file faandct.c
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24 | ```
* @brief
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25 | ```
* Floating point AAN DCT
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26 | ```
* @author Michael Niedermayer <michaelni@gmx.at>
``` |
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27 | ```
*/
``` |
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28 | |||

29 | #include <math.h> |
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30 | |||

31 | #include "dsputil.h" |
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32 | #include "faandct.h" |
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33 | |||

34 | #define FLOAT float |
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35 | b4c3816c | Michael Niedermayer | ```
#ifdef FAAN_POSTSCALE
``` |

36 | ```
# define SCALE(x) postscale[x]
``` |
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37 | ```
#else
``` |
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38 | # define SCALE(x) 1 |
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39 | ```
#endif
``` |
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40 | 65e4c8c9 | Michael Niedermayer | |

41 | ```
//numbers generated by simple c code (not as accurate as they could be)
``` |
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42 | ```
/*
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43 | ```
for(i=0; i<8; i++){
``` |
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44 | ```
printf("#define B%d %1.20llf\n", i, (long double)1.0/(cosl(i*acosl(-1.0)/(long double)16.0)*sqrtl(2)));
``` |
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45 | ```
}
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46 | ```
*/
``` |
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47 | #define B0 1.00000000000000000000 |
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48 | #define B1 0.72095982200694791383 // (cos(pi*1/16)sqrt(2))^-1 |
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49 | #define B2 0.76536686473017954350 // (cos(pi*2/16)sqrt(2))^-1 |
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50 | #define B3 0.85043009476725644878 // (cos(pi*3/16)sqrt(2))^-1 |
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51 | #define B4 1.00000000000000000000 // (cos(pi*4/16)sqrt(2))^-1 |
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52 | #define B5 1.27275858057283393842 // (cos(pi*5/16)sqrt(2))^-1 |
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53 | #define B6 1.84775906502257351242 // (cos(pi*6/16)sqrt(2))^-1 |
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54 | #define B7 3.62450978541155137218 // (cos(pi*7/16)sqrt(2))^-1 |
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55 | |||

56 | |||

57 | #define A1 0.70710678118654752438 // cos(pi*4/16) |
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58 | #define A2 0.54119610014619698435 // cos(pi*6/16)sqrt(2) |
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59 | #define A5 0.38268343236508977170 // cos(pi*6/16) |
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60 | #define A4 1.30656296487637652774 // cos(pi*2/16)sqrt(2) |
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61 | |||

62 | static FLOAT postscale[64]={ |
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63 | B0*B0, B0*B1, B0*B2, B0*B3, B0*B4, B0*B5, B0*B6, B0*B7, |
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64 | B1*B0, B1*B1, B1*B2, B1*B3, B1*B4, B1*B5, B1*B6, B1*B7, |
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65 | B2*B0, B2*B1, B2*B2, B2*B3, B2*B4, B2*B5, B2*B6, B2*B7, |
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66 | B3*B0, B3*B1, B3*B2, B3*B3, B3*B4, B3*B5, B3*B6, B3*B7, |
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67 | B4*B0, B4*B1, B4*B2, B4*B3, B4*B4, B4*B5, B4*B6, B4*B7, |
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68 | B5*B0, B5*B1, B5*B2, B5*B3, B5*B4, B5*B5, B5*B6, B5*B7, |
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69 | B6*B0, B6*B1, B6*B2, B6*B3, B6*B4, B6*B5, B6*B6, B6*B7, |
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70 | B7*B0, B7*B1, B7*B2, B7*B3, B7*B4, B7*B5, B7*B6, B7*B7, |
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71 | }; |
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72 | |||

73 | d43fb4e8 | Michael Niedermayer | static always_inline void row_fdct(FLOAT temp[64], DCTELEM * data) |

74 | 65e4c8c9 | Michael Niedermayer | { |

75 | FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; |
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76 | FLOAT tmp10, tmp11, tmp12, tmp13; |
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77 | FLOAT z1, z2, z3, z4, z5, z11, z13; |
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78 | ```
int i;
``` |
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79 | |||

80 | for (i=0; i<8*8; i+=8) { |
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81 | tmp0= data[0 + i] + data[7 + i]; |
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82 | tmp7= data[0 + i] - data[7 + i]; |
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83 | tmp1= data[1 + i] + data[6 + i]; |
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84 | tmp6= data[1 + i] - data[6 + i]; |
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85 | tmp2= data[2 + i] + data[5 + i]; |
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86 | tmp5= data[2 + i] - data[5 + i]; |
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87 | tmp3= data[3 + i] + data[4 + i]; |
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88 | tmp4= data[3 + i] - data[4 + i]; |
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89 | |||

90 | tmp10= tmp0 + tmp3; |
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91 | tmp13= tmp0 - tmp3; |
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92 | tmp11= tmp1 + tmp2; |
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93 | tmp12= tmp1 - tmp2; |
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94 | |||

95 | ```
temp[0 + i]= tmp10 + tmp11;
``` |
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96 | ```
temp[4 + i]= tmp10 - tmp11;
``` |
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97 | |||

98 | z1= (tmp12 + tmp13)*A1; |
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99 | ```
temp[2 + i]= tmp13 + z1;
``` |
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100 | ```
temp[6 + i]= tmp13 - z1;
``` |
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101 | |||

102 | tmp10= tmp4 + tmp5; |
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103 | tmp11= tmp5 + tmp6; |
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104 | tmp12= tmp6 + tmp7; |
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105 | |||

106 | z5= (tmp10 - tmp12) * A5; |
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107 | z2= tmp10*A2 + z5; |
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108 | z4= tmp12*A4 + z5; |
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109 | z3= tmp11*A1; |
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110 | |||

111 | z11= tmp7 + z3; |
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112 | z13= tmp7 - z3; |
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113 | |||

114 | ```
temp[5 + i]= z13 + z2;
``` |
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115 | ```
temp[3 + i]= z13 - z2;
``` |
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116 | ```
temp[1 + i]= z11 + z4;
``` |
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117 | ```
temp[7 + i]= z11 - z4;
``` |
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118 | d43fb4e8 | Michael Niedermayer | } |

119 | } |
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120 | |||

121 | ```
void ff_faandct(DCTELEM * data)
``` |
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122 | { |
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123 | FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; |
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124 | FLOAT tmp10, tmp11, tmp12, tmp13; |
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125 | FLOAT z1, z2, z3, z4, z5, z11, z13; |
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126 | ```
FLOAT temp[64];
``` |
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127 | ```
int i;
``` |
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128 | |||

129 | emms_c(); |
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130 | |||

131 | row_fdct(temp, data); |
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132 | 65e4c8c9 | Michael Niedermayer | |

133 | for (i=0; i<8; i++) { |
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134 | tmp0= temp[8*0 + i] + temp[8*7 + i]; |
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135 | tmp7= temp[8*0 + i] - temp[8*7 + i]; |
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136 | tmp1= temp[8*1 + i] + temp[8*6 + i]; |
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137 | tmp6= temp[8*1 + i] - temp[8*6 + i]; |
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138 | tmp2= temp[8*2 + i] + temp[8*5 + i]; |
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139 | tmp5= temp[8*2 + i] - temp[8*5 + i]; |
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140 | tmp3= temp[8*3 + i] + temp[8*4 + i]; |
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141 | tmp4= temp[8*3 + i] - temp[8*4 + i]; |
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142 | |||

143 | tmp10= tmp0 + tmp3; |
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144 | tmp13= tmp0 - tmp3; |
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145 | tmp11= tmp1 + tmp2; |
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146 | tmp12= tmp1 - tmp2; |
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147 | |||

148 | 8d00c562 | Michael Niedermayer | data[8*0 + i]= lrintf(SCALE(8*0 + i) * (tmp10 + tmp11)); |

149 | data[8*4 + i]= lrintf(SCALE(8*4 + i) * (tmp10 - tmp11)); |
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150 | 65e4c8c9 | Michael Niedermayer | |

151 | z1= (tmp12 + tmp13)* A1; |
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152 | 8d00c562 | Michael Niedermayer | data[8*2 + i]= lrintf(SCALE(8*2 + i) * (tmp13 + z1)); |

153 | data[8*6 + i]= lrintf(SCALE(8*6 + i) * (tmp13 - z1)); |
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154 | 65e4c8c9 | Michael Niedermayer | |

155 | tmp10= tmp4 + tmp5; |
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156 | tmp11= tmp5 + tmp6; |
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157 | tmp12= tmp6 + tmp7; |
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158 | |||

159 | z5= (tmp10 - tmp12) * A5; |
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160 | z2= tmp10*A2 + z5; |
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161 | z4= tmp12*A4 + z5; |
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162 | z3= tmp11*A1; |
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163 | |||

164 | z11= tmp7 + z3; |
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165 | z13= tmp7 - z3; |
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166 | |||

167 | 8d00c562 | Michael Niedermayer | data[8*5 + i]= lrintf(SCALE(8*5 + i) * (z13 + z2)); |

168 | data[8*3 + i]= lrintf(SCALE(8*3 + i) * (z13 - z2)); |
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169 | data[8*1 + i]= lrintf(SCALE(8*1 + i) * (z11 + z4)); |
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170 | data[8*7 + i]= lrintf(SCALE(8*7 + i) * (z11 - z4)); |
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171 | 65e4c8c9 | Michael Niedermayer | } |

172 | } |
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173 | 48b1f800 | Roman Shaposhnik | |

174 | ```
void ff_faandct248(DCTELEM * data)
``` |
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175 | { |
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176 | FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; |
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177 | FLOAT tmp10, tmp11, tmp12, tmp13; |
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178 | d43fb4e8 | Michael Niedermayer | FLOAT z1; |

179 | 48b1f800 | Roman Shaposhnik | ```
FLOAT temp[64];
``` |

180 | ```
int i;
``` |
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181 | |||

182 | emms_c(); |
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183 | |||

184 | d43fb4e8 | Michael Niedermayer | row_fdct(temp, data); |

185 | 48b1f800 | Roman Shaposhnik | |

186 | for (i=0; i<8; i++) { |
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187 | tmp0 = temp[8*0 + i] + temp[8*1 + i]; |
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188 | tmp1 = temp[8*2 + i] + temp[8*3 + i]; |
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189 | tmp2 = temp[8*4 + i] + temp[8*5 + i]; |
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190 | tmp3 = temp[8*6 + i] + temp[8*7 + i]; |
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191 | tmp4 = temp[8*0 + i] - temp[8*1 + i]; |
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192 | tmp5 = temp[8*2 + i] - temp[8*3 + i]; |
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193 | tmp6 = temp[8*4 + i] - temp[8*5 + i]; |
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194 | tmp7 = temp[8*6 + i] - temp[8*7 + i]; |
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195 | |||

196 | tmp10 = tmp0 + tmp3; |
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197 | tmp11 = tmp1 + tmp2; |
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198 | tmp12 = tmp1 - tmp2; |
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199 | tmp13 = tmp0 - tmp3; |
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200 | |||

201 | data[8*0 + i] = lrintf(SCALE(8*0 + i) * (tmp10 + tmp11)); |
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202 | data[8*4 + i] = lrintf(SCALE(8*4 + i) * (tmp10 - tmp11)); |
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203 | |||

204 | z1 = (tmp12 + tmp13)* A1; |
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205 | data[8*2 + i] = lrintf(SCALE(8*2 + i) * (tmp13 + z1)); |
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206 | data[8*6 + i] = lrintf(SCALE(8*6 + i) * (tmp13 - z1)); |
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207 | |||

208 | tmp10 = tmp4 + tmp7; |
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209 | tmp11 = tmp5 + tmp6; |
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210 | tmp12 = tmp5 - tmp6; |
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211 | tmp13 = tmp4 - tmp7; |
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212 | |||

213 | data[8*1 + i] = lrintf(SCALE(8*0 + i) * (tmp10 + tmp11)); |
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214 | data[8*5 + i] = lrintf(SCALE(8*4 + i) * (tmp10 - tmp11)); |
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215 | |||

216 | z1 = (tmp12 + tmp13)* A1; |
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217 | data[8*3 + i] = lrintf(SCALE(8*2 + i) * (tmp13 + z1)); |
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218 | data[8*7 + i] = lrintf(SCALE(8*6 + i) * (tmp13 - z1)); |
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219 | } |
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220 | } |