ffmpeg / libavcodec / faandct.c @ 5509bffa
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/*


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* Floating point AAN DCT

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* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>

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*

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* This library is free software; you can redistribute it and/or

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* modify it under the terms of the GNU Lesser General Public

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* License as published by the Free Software Foundation; either

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* version 2 of the License, or (at your option) any later version.

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*

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* This library is distributed in the hope that it will be useful,

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* but WITHOUT ANY WARRANTY; without even the implied warranty of

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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

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* Lesser General Public License for more details.

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*

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* You should have received a copy of the GNU Lesser General Public

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* License along with this library; if not, write to the Free Software

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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 021101301 USA

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*

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* this implementation is based upon the IJG integer AAN DCT (see jfdctfst.c)

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*/

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/**

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* @file faandct.c

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* @brief

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* Floating point AAN DCT

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* @author Michael Niedermayer <michaelni@gmx.at>

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*/

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#include "dsputil.h" 
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#include "faandct.h" 
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#define FLOAT float 
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#ifdef FAAN_POSTSCALE

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# define SCALE(x) postscale[x]

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#else

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# define SCALE(x) 1 
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#endif

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//numbers generated by simple c code (not as accurate as they could be)

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/*

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for(i=0; i<8; i++){

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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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}

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*/

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#define B0 1.00000000000000000000 
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#define B1 0.72095982200694791383 // (cos(pi*1/16)sqrt(2))^1 
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#define B2 0.76536686473017954350 // (cos(pi*2/16)sqrt(2))^1 
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#define B3 0.85043009476725644878 // (cos(pi*3/16)sqrt(2))^1 
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#define B4 1.00000000000000000000 // (cos(pi*4/16)sqrt(2))^1 
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#define B5 1.27275858057283393842 // (cos(pi*5/16)sqrt(2))^1 
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#define B6 1.84775906502257351242 // (cos(pi*6/16)sqrt(2))^1 
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#define B7 3.62450978541155137218 // (cos(pi*7/16)sqrt(2))^1 
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#define A1 0.70710678118654752438 // cos(pi*4/16) 
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#define A2 0.54119610014619698435 // cos(pi*6/16)sqrt(2) 
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#define A5 0.38268343236508977170 // cos(pi*6/16) 
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#define A4 1.30656296487637652774 // cos(pi*2/16)sqrt(2) 
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static FLOAT postscale[64]={ 
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B0*B0, B0*B1, B0*B2, B0*B3, B0*B4, B0*B5, B0*B6, B0*B7, 
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B1*B0, B1*B1, B1*B2, B1*B3, B1*B4, B1*B5, B1*B6, B1*B7, 
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B2*B0, B2*B1, B2*B2, B2*B3, B2*B4, B2*B5, B2*B6, B2*B7, 
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B3*B0, B3*B1, B3*B2, B3*B3, B3*B4, B3*B5, B3*B6, B3*B7, 
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B4*B0, B4*B1, B4*B2, B4*B3, B4*B4, B4*B5, B4*B6, B4*B7, 
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B5*B0, B5*B1, B5*B2, B5*B3, B5*B4, B5*B5, B5*B6, B5*B7, 
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B6*B0, B6*B1, B6*B2, B6*B3, B6*B4, B6*B5, B6*B6, B6*B7, 
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B7*B0, B7*B1, B7*B2, B7*B3, B7*B4, B7*B5, B7*B6, B7*B7, 
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}; 
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static always_inline void row_fdct(FLOAT temp[64], DCTELEM * data) 
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{ 
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FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; 
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FLOAT tmp10, tmp11, tmp12, tmp13; 
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FLOAT z1, z2, z3, z4, z5, z11, z13; 
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int i;

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for (i=0; i<8*8; i+=8) { 
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tmp0= data[0 + i] + data[7 + i]; 
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tmp7= data[0 + i]  data[7 + i]; 
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tmp1= data[1 + i] + data[6 + i]; 
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tmp6= data[1 + i]  data[6 + i]; 
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tmp2= data[2 + i] + data[5 + i]; 
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tmp5= data[2 + i]  data[5 + i]; 
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tmp3= data[3 + i] + data[4 + i]; 
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tmp4= data[3 + i]  data[4 + i]; 
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tmp10= tmp0 + tmp3; 
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tmp13= tmp0  tmp3; 
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tmp11= tmp1 + tmp2; 
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tmp12= tmp1  tmp2; 
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temp[0 + i]= tmp10 + tmp11;

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temp[4 + i]= tmp10  tmp11;

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z1= (tmp12 + tmp13)*A1; 
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temp[2 + i]= tmp13 + z1;

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temp[6 + i]= tmp13  z1;

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tmp10= tmp4 + tmp5; 
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tmp11= tmp5 + tmp6; 
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tmp12= tmp6 + tmp7; 
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z5= (tmp10  tmp12) * A5; 
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z2= tmp10*A2 + z5; 
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z4= tmp12*A4 + z5; 
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z3= tmp11*A1; 
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z11= tmp7 + z3; 
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z13= tmp7  z3; 
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temp[5 + i]= z13 + z2;

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temp[3 + i]= z13  z2;

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temp[1 + i]= z11 + z4;

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temp[7 + i]= z11  z4;

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} 
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} 
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void ff_faandct(DCTELEM * data)

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{ 
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FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; 
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FLOAT tmp10, tmp11, tmp12, tmp13; 
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FLOAT z1, z2, z3, z4, z5, z11, z13; 
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FLOAT temp[64];

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int i;

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emms_c(); 
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row_fdct(temp, data); 
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for (i=0; i<8; i++) { 
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tmp0= temp[8*0 + i] + temp[8*7 + i]; 
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tmp7= temp[8*0 + i]  temp[8*7 + i]; 
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tmp1= temp[8*1 + i] + temp[8*6 + i]; 
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tmp6= temp[8*1 + i]  temp[8*6 + i]; 
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tmp2= temp[8*2 + i] + temp[8*5 + i]; 
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tmp5= temp[8*2 + i]  temp[8*5 + i]; 
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tmp3= temp[8*3 + i] + temp[8*4 + i]; 
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tmp4= temp[8*3 + i]  temp[8*4 + i]; 
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tmp10= tmp0 + tmp3; 
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tmp13= tmp0  tmp3; 
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tmp11= tmp1 + tmp2; 
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tmp12= tmp1  tmp2; 
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data[8*0 + i]= lrintf(SCALE(8*0 + i) * (tmp10 + tmp11)); 
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data[8*4 + i]= lrintf(SCALE(8*4 + i) * (tmp10  tmp11)); 
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z1= (tmp12 + tmp13)* A1; 
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data[8*2 + i]= lrintf(SCALE(8*2 + i) * (tmp13 + z1)); 
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data[8*6 + i]= lrintf(SCALE(8*6 + i) * (tmp13  z1)); 
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tmp10= tmp4 + tmp5; 
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tmp11= tmp5 + tmp6; 
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tmp12= tmp6 + tmp7; 
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z5= (tmp10  tmp12) * A5; 
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z2= tmp10*A2 + z5; 
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z4= tmp12*A4 + z5; 
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z3= tmp11*A1; 
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z11= tmp7 + z3; 
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z13= tmp7  z3; 
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data[8*5 + i]= lrintf(SCALE(8*5 + i) * (z13 + z2)); 
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data[8*3 + i]= lrintf(SCALE(8*3 + i) * (z13  z2)); 
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data[8*1 + i]= lrintf(SCALE(8*1 + i) * (z11 + z4)); 
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data[8*7 + i]= lrintf(SCALE(8*7 + i) * (z11  z4)); 
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} 
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} 
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void ff_faandct248(DCTELEM * data)

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{ 
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FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; 
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FLOAT tmp10, tmp11, tmp12, tmp13; 
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FLOAT z1; 
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FLOAT temp[64];

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int i;

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emms_c(); 
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row_fdct(temp, data); 
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for (i=0; i<8; i++) { 
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tmp0 = temp[8*0 + i] + temp[8*1 + i]; 
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tmp1 = temp[8*2 + i] + temp[8*3 + i]; 
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tmp2 = temp[8*4 + i] + temp[8*5 + i]; 
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tmp3 = temp[8*6 + i] + temp[8*7 + i]; 
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tmp4 = temp[8*0 + i]  temp[8*1 + i]; 
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tmp5 = temp[8*2 + i]  temp[8*3 + i]; 
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tmp6 = temp[8*4 + i]  temp[8*5 + i]; 
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tmp7 = temp[8*6 + i]  temp[8*7 + i]; 
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tmp10 = tmp0 + tmp3; 
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tmp11 = tmp1 + tmp2; 
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tmp12 = tmp1  tmp2; 
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tmp13 = tmp0  tmp3; 
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data[8*0 + i] = lrintf(SCALE(8*0 + i) * (tmp10 + tmp11)); 
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data[8*4 + i] = lrintf(SCALE(8*4 + i) * (tmp10  tmp11)); 
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z1 = (tmp12 + tmp13)* A1; 
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data[8*2 + i] = lrintf(SCALE(8*2 + i) * (tmp13 + z1)); 
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data[8*6 + i] = lrintf(SCALE(8*6 + i) * (tmp13  z1)); 
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tmp10 = tmp4 + tmp7; 
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tmp11 = tmp5 + tmp6; 
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tmp12 = tmp5  tmp6; 
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tmp13 = tmp4  tmp7; 
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data[8*1 + i] = lrintf(SCALE(8*0 + i) * (tmp10 + tmp11)); 
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data[8*5 + i] = lrintf(SCALE(8*4 + i) * (tmp10  tmp11)); 
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z1 = (tmp12 + tmp13)* A1; 
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data[8*3 + i] = lrintf(SCALE(8*2 + i) * (tmp13 + z1)); 
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data[8*7 + i] = lrintf(SCALE(8*6 + i) * (tmp13  z1)); 
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} 
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} 