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


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* Simple IDCT

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*

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* Copyright (c) 2001 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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/**

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* @file simple_idct.c

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* simpleidct in C.

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*/

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/*

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based upon some outcommented c code from mpeg2dec (idct_mmx.c

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written by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>)

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*/

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#include "avcodec.h" 
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#include "dsputil.h" 
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#include "simple_idct.h" 
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#if 0

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#define W1 2841 /* 2048*sqrt (2)*cos (1*pi/16) */

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#define W2 2676 /* 2048*sqrt (2)*cos (2*pi/16) */

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#define W3 2408 /* 2048*sqrt (2)*cos (3*pi/16) */

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#define W4 2048 /* 2048*sqrt (2)*cos (4*pi/16) */

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#define W5 1609 /* 2048*sqrt (2)*cos (5*pi/16) */

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#define W6 1108 /* 2048*sqrt (2)*cos (6*pi/16) */

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#define W7 565 /* 2048*sqrt (2)*cos (7*pi/16) */

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#define ROW_SHIFT 8

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#define COL_SHIFT 17

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#else

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#define W1 22725 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5 
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#define W2 21407 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5 
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#define W3 19266 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5 
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#define W4 16383 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5 
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#define W5 12873 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5 
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#define W6 8867 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5 
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#define W7 4520 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5 
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#define ROW_SHIFT 11 
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#define COL_SHIFT 20 // 6 
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#endif

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#if defined(ARCH_POWERPC_405)

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/* signed 16x16 > 32 multiply add accumulate */

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#define MAC16(rt, ra, rb) \

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asm ("maclhw %0, %2, %3" : "=r" (rt) : "0" (rt), "r" (ra), "r" (rb)); 
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/* signed 16x16 > 32 multiply */

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#define MUL16(rt, ra, rb) \

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asm ("mullhw %0, %1, %2" : "=r" (rt) : "r" (ra), "r" (rb)); 
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#else

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/* signed 16x16 > 32 multiply add accumulate */

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#define MAC16(rt, ra, rb) rt += (ra) * (rb)

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/* signed 16x16 > 32 multiply */

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#define MUL16(rt, ra, rb) rt = (ra) * (rb)

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#endif

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static inline void idctRowCondDC (DCTELEM * row) 
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{ 
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int a0, a1, a2, a3, b0, b1, b2, b3;

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#ifdef FAST_64BIT

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uint64_t temp; 
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#else

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uint32_t temp; 
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#endif

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#ifdef FAST_64BIT

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#ifdef WORDS_BIGENDIAN

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#define ROW0_MASK 0xffff000000000000LL 
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#else

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#define ROW0_MASK 0xffffLL 
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#endif

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if(sizeof(DCTELEM)==2){ 
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if ( ((((uint64_t *)row)[0] & ~ROW0_MASK)  
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((uint64_t *)row)[1]) == 0) { 
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temp = (row[0] << 3) & 0xffff; 
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temp += temp << 16;

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temp += temp << 32;

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((uint64_t *)row)[0] = temp;

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((uint64_t *)row)[1] = temp;

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return;

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} 
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}else{

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if (!(row[1]row[2]row[3]row[4]row[5]row[6]row[7])) { 
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row[0]=row[1]=row[2]=row[3]=row[4]=row[5]=row[6]=row[7]= row[0] << 3; 
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return;

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} 
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} 
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#else

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if(sizeof(DCTELEM)==2){ 
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if (!(((uint32_t*)row)[1]  
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((uint32_t*)row)[2] 

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((uint32_t*)row)[3] 

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row[1])) {

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temp = (row[0] << 3) & 0xffff; 
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temp += temp << 16;

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((uint32_t*)row)[0]=((uint32_t*)row)[1] = 
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((uint32_t*)row)[2]=((uint32_t*)row)[3] = temp; 
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return;

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} 
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}else{

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if (!(row[1]row[2]row[3]row[4]row[5]row[6]row[7])) { 
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row[0]=row[1]=row[2]=row[3]=row[4]=row[5]=row[6]=row[7]= row[0] << 3; 
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return;

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} 
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} 
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#endif

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a0 = (W4 * row[0]) + (1 << (ROW_SHIFT  1)); 
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a1 = a0; 
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a2 = a0; 
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a3 = a0; 
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/* no need to optimize : gcc does it */

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a0 += W2 * row[2];

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a1 += W6 * row[2];

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a2 = W6 * row[2];

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a3 = W2 * row[2];

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MUL16(b0, W1, row[1]);

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MAC16(b0, W3, row[3]);

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MUL16(b1, W3, row[1]);

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MAC16(b1, W7, row[3]);

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MUL16(b2, W5, row[1]);

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MAC16(b2, W1, row[3]);

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MUL16(b3, W7, row[1]);

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MAC16(b3, W5, row[3]);

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#ifdef FAST_64BIT

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temp = ((uint64_t*)row)[1];

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#else

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temp = ((uint32_t*)row)[2]  ((uint32_t*)row)[3]; 
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#endif

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if (temp != 0) { 
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a0 += W4*row[4] + W6*row[6]; 
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a1 +=  W4*row[4]  W2*row[6]; 
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a2 +=  W4*row[4] + W2*row[6]; 
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a3 += W4*row[4]  W6*row[6]; 
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MAC16(b0, W5, row[5]);

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MAC16(b0, W7, row[7]);

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MAC16(b1, W1, row[5]);

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MAC16(b1, W5, row[7]);

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MAC16(b2, W7, row[5]);

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MAC16(b2, W3, row[7]);

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MAC16(b3, W3, row[5]);

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MAC16(b3, W1, row[7]);

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} 
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row[0] = (a0 + b0) >> ROW_SHIFT;

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row[7] = (a0  b0) >> ROW_SHIFT;

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row[1] = (a1 + b1) >> ROW_SHIFT;

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row[6] = (a1  b1) >> ROW_SHIFT;

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row[2] = (a2 + b2) >> ROW_SHIFT;

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row[5] = (a2  b2) >> ROW_SHIFT;

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row[3] = (a3 + b3) >> ROW_SHIFT;

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row[4] = (a3  b3) >> ROW_SHIFT;

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} 
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static inline void idctSparseColPut (uint8_t *dest, int line_size, 
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DCTELEM * col) 
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{ 
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int a0, a1, a2, a3, b0, b1, b2, b3;

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uint8_t *cm = cropTbl + MAX_NEG_CROP; 
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/* XXX: I did that only to give same values as previous code */

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a0 = W4 * (col[8*0] + ((1<<(COL_SHIFT1))/W4)); 
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a1 = a0; 
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a2 = a0; 
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a3 = a0; 
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a0 += + W2*col[8*2]; 
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a1 += + W6*col[8*2]; 
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a2 +=  W6*col[8*2]; 
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a3 +=  W2*col[8*2]; 
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MUL16(b0, W1, col[8*1]); 
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MUL16(b1, W3, col[8*1]); 
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MUL16(b2, W5, col[8*1]); 
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MUL16(b3, W7, col[8*1]); 
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MAC16(b0, + W3, col[8*3]); 
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MAC16(b1,  W7, col[8*3]); 
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MAC16(b2,  W1, col[8*3]); 
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MAC16(b3,  W5, col[8*3]); 
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if(col[8*4]){ 
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a0 += + W4*col[8*4]; 
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a1 +=  W4*col[8*4]; 
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a2 +=  W4*col[8*4]; 
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a3 += + W4*col[8*4]; 
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} 
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if (col[8*5]) { 
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MAC16(b0, + W5, col[8*5]); 
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MAC16(b1,  W1, col[8*5]); 
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MAC16(b2, + W7, col[8*5]); 
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MAC16(b3, + W3, col[8*5]); 
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} 
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if(col[8*6]){ 
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a0 += + W6*col[8*6]; 
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a1 +=  W2*col[8*6]; 
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a2 += + W2*col[8*6]; 
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a3 +=  W6*col[8*6]; 
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} 
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if (col[8*7]) { 
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MAC16(b0, + W7, col[8*7]); 
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MAC16(b1,  W5, col[8*7]); 
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MAC16(b2, + W3, col[8*7]); 
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MAC16(b3,  W1, col[8*7]); 
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} 
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dest[0] = cm[(a0 + b0) >> COL_SHIFT];

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dest += line_size; 
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dest[0] = cm[(a1 + b1) >> COL_SHIFT];

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dest += line_size; 
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dest[0] = cm[(a2 + b2) >> COL_SHIFT];

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dest += line_size; 
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dest[0] = cm[(a3 + b3) >> COL_SHIFT];

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dest += line_size; 
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dest[0] = cm[(a3  b3) >> COL_SHIFT];

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dest += line_size; 
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dest[0] = cm[(a2  b2) >> COL_SHIFT];

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dest += line_size; 
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dest[0] = cm[(a1  b1) >> COL_SHIFT];

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dest += line_size; 
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dest[0] = cm[(a0  b0) >> COL_SHIFT];

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} 
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static inline void idctSparseColAdd (uint8_t *dest, int line_size, 
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DCTELEM * col) 
255 
{ 
256 
int a0, a1, a2, a3, b0, b1, b2, b3;

257 
uint8_t *cm = cropTbl + MAX_NEG_CROP; 
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259 
/* XXX: I did that only to give same values as previous code */

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a0 = W4 * (col[8*0] + ((1<<(COL_SHIFT1))/W4)); 
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a1 = a0; 
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a2 = a0; 
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a3 = a0; 
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a0 += + W2*col[8*2]; 
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a1 += + W6*col[8*2]; 
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a2 +=  W6*col[8*2]; 
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a3 +=  W2*col[8*2]; 
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MUL16(b0, W1, col[8*1]); 
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MUL16(b1, W3, col[8*1]); 
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MUL16(b2, W5, col[8*1]); 
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MUL16(b3, W7, col[8*1]); 
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MAC16(b0, + W3, col[8*3]); 
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MAC16(b1,  W7, col[8*3]); 
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MAC16(b2,  W1, col[8*3]); 
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MAC16(b3,  W5, col[8*3]); 
279  
280 
if(col[8*4]){ 
281 
a0 += + W4*col[8*4]; 
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a1 +=  W4*col[8*4]; 
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a2 +=  W4*col[8*4]; 
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a3 += + W4*col[8*4]; 
285 
} 
286  
287 
if (col[8*5]) { 
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MAC16(b0, + W5, col[8*5]); 
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MAC16(b1,  W1, col[8*5]); 
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MAC16(b2, + W7, col[8*5]); 
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MAC16(b3, + W3, col[8*5]); 
292 
} 
293  
294 
if(col[8*6]){ 
295 
a0 += + W6*col[8*6]; 
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a1 +=  W2*col[8*6]; 
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a2 += + W2*col[8*6]; 
298 
a3 +=  W6*col[8*6]; 
299 
} 
300  
301 
if (col[8*7]) { 
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MAC16(b0, + W7, col[8*7]); 
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MAC16(b1,  W5, col[8*7]); 
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MAC16(b2, + W3, col[8*7]); 
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MAC16(b3,  W1, col[8*7]); 
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} 
307  
308 
dest[0] = cm[dest[0] + ((a0 + b0) >> COL_SHIFT)]; 
309 
dest += line_size; 
310 
dest[0] = cm[dest[0] + ((a1 + b1) >> COL_SHIFT)]; 
311 
dest += line_size; 
312 
dest[0] = cm[dest[0] + ((a2 + b2) >> COL_SHIFT)]; 
313 
dest += line_size; 
314 
dest[0] = cm[dest[0] + ((a3 + b3) >> COL_SHIFT)]; 
315 
dest += line_size; 
316 
dest[0] = cm[dest[0] + ((a3  b3) >> COL_SHIFT)]; 
317 
dest += line_size; 
318 
dest[0] = cm[dest[0] + ((a2  b2) >> COL_SHIFT)]; 
319 
dest += line_size; 
320 
dest[0] = cm[dest[0] + ((a1  b1) >> COL_SHIFT)]; 
321 
dest += line_size; 
322 
dest[0] = cm[dest[0] + ((a0  b0) >> COL_SHIFT)]; 
323 
} 
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325 
static inline void idctSparseCol (DCTELEM * col) 
326 
{ 
327 
int a0, a1, a2, a3, b0, b1, b2, b3;

328  
329 
/* XXX: I did that only to give same values as previous code */

330 
a0 = W4 * (col[8*0] + ((1<<(COL_SHIFT1))/W4)); 
331 
a1 = a0; 
332 
a2 = a0; 
333 
a3 = a0; 
334  
335 
a0 += + W2*col[8*2]; 
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a1 += + W6*col[8*2]; 
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a2 +=  W6*col[8*2]; 
338 
a3 +=  W2*col[8*2]; 
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340 
MUL16(b0, W1, col[8*1]); 
341 
MUL16(b1, W3, col[8*1]); 
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MUL16(b2, W5, col[8*1]); 
343 
MUL16(b3, W7, col[8*1]); 
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345 
MAC16(b0, + W3, col[8*3]); 
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MAC16(b1,  W7, col[8*3]); 
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MAC16(b2,  W1, col[8*3]); 
348 
MAC16(b3,  W5, col[8*3]); 
349  
350 
if(col[8*4]){ 
351 
a0 += + W4*col[8*4]; 
352 
a1 +=  W4*col[8*4]; 
353 
a2 +=  W4*col[8*4]; 
354 
a3 += + W4*col[8*4]; 
355 
} 
356  
357 
if (col[8*5]) { 
358 
MAC16(b0, + W5, col[8*5]); 
359 
MAC16(b1,  W1, col[8*5]); 
360 
MAC16(b2, + W7, col[8*5]); 
361 
MAC16(b3, + W3, col[8*5]); 
362 
} 
363  
364 
if(col[8*6]){ 
365 
a0 += + W6*col[8*6]; 
366 
a1 +=  W2*col[8*6]; 
367 
a2 += + W2*col[8*6]; 
368 
a3 +=  W6*col[8*6]; 
369 
} 
370  
371 
if (col[8*7]) { 
372 
MAC16(b0, + W7, col[8*7]); 
373 
MAC16(b1,  W5, col[8*7]); 
374 
MAC16(b2, + W3, col[8*7]); 
375 
MAC16(b3,  W1, col[8*7]); 
376 
} 
377  
378 
col[0 ] = ((a0 + b0) >> COL_SHIFT);

379 
col[8 ] = ((a1 + b1) >> COL_SHIFT);

380 
col[16] = ((a2 + b2) >> COL_SHIFT);

381 
col[24] = ((a3 + b3) >> COL_SHIFT);

382 
col[32] = ((a3  b3) >> COL_SHIFT);

383 
col[40] = ((a2  b2) >> COL_SHIFT);

384 
col[48] = ((a1  b1) >> COL_SHIFT);

385 
col[56] = ((a0  b0) >> COL_SHIFT);

386 
} 
387  
388 
void simple_idct_put(uint8_t *dest, int line_size, DCTELEM *block) 
389 
{ 
390 
int i;

391 
for(i=0; i<8; i++) 
392 
idctRowCondDC(block + i*8);

393  
394 
for(i=0; i<8; i++) 
395 
idctSparseColPut(dest + i, line_size, block + i); 
396 
} 
397  
398 
void simple_idct_add(uint8_t *dest, int line_size, DCTELEM *block) 
399 
{ 
400 
int i;

401 
for(i=0; i<8; i++) 
402 
idctRowCondDC(block + i*8);

403  
404 
for(i=0; i<8; i++) 
405 
idctSparseColAdd(dest + i, line_size, block + i); 
406 
} 
407  
408 
void simple_idct(DCTELEM *block)

409 
{ 
410 
int i;

411 
for(i=0; i<8; i++) 
412 
idctRowCondDC(block + i*8);

413  
414 
for(i=0; i<8; i++) 
415 
idctSparseCol(block + i); 
416 
} 
417  
418 
/* 2x4x8 idct */

419  
420 
#define CN_SHIFT 12 
421 
#define C_FIX(x) ((int)((x) * (1 << CN_SHIFT) + 0.5)) 
422 
#define C1 C_FIX(0.6532814824) 
423 
#define C2 C_FIX(0.2705980501) 
424  
425 
/* row idct is multiple by 16 * sqrt(2.0), col idct4 is normalized,

426 
and the butterfly must be multiplied by 0.5 * sqrt(2.0) */

427 
#define C_SHIFT (4+1+12) 
428  
429 
static inline void idct4col(uint8_t *dest, int line_size, const DCTELEM *col) 
430 
{ 
431 
int c0, c1, c2, c3, a0, a1, a2, a3;

432 
const uint8_t *cm = cropTbl + MAX_NEG_CROP;

433  
434 
a0 = col[8*0]; 
435 
a1 = col[8*2]; 
436 
a2 = col[8*4]; 
437 
a3 = col[8*6]; 
438 
c0 = ((a0 + a2) << (CN_SHIFT  1)) + (1 << (C_SHIFT  1)); 
439 
c2 = ((a0  a2) << (CN_SHIFT  1)) + (1 << (C_SHIFT  1)); 
440 
c1 = a1 * C1 + a3 * C2; 
441 
c3 = a1 * C2  a3 * C1; 
442 
dest[0] = cm[(c0 + c1) >> C_SHIFT];

443 
dest += line_size; 
444 
dest[0] = cm[(c2 + c3) >> C_SHIFT];

445 
dest += line_size; 
446 
dest[0] = cm[(c2  c3) >> C_SHIFT];

447 
dest += line_size; 
448 
dest[0] = cm[(c0  c1) >> C_SHIFT];

449 
} 
450  
451 
#define BF(k) \

452 
{\ 
453 
int a0, a1;\

454 
a0 = ptr[k];\ 
455 
a1 = ptr[8 + k];\

456 
ptr[k] = a0 + a1;\ 
457 
ptr[8 + k] = a0  a1;\

458 
} 
459  
460 
/* only used by DV codec. The input must be interlaced. 128 is added

461 
to the pixels before clamping to avoid systematic error

462 
(1024*sqrt(2)) offset would be needed otherwise. */

463 
/* XXX: I think a 1.0/sqrt(2) normalization should be needed to

464 
compensate the extra butterfly stage  I don't have the full DV

465 
specification */

466 
void simple_idct248_put(uint8_t *dest, int line_size, DCTELEM *block) 
467 
{ 
468 
int i;

469 
DCTELEM *ptr; 
470  
471 
/* butterfly */

472 
ptr = block; 
473 
for(i=0;i<4;i++) { 
474 
BF(0);

475 
BF(1);

476 
BF(2);

477 
BF(3);

478 
BF(4);

479 
BF(5);

480 
BF(6);

481 
BF(7);

482 
ptr += 2 * 8; 
483 
} 
484  
485 
/* IDCT8 on each line */

486 
for(i=0; i<8; i++) { 
487 
idctRowCondDC(block + i*8);

488 
} 
489  
490 
/* IDCT4 and store */

491 
for(i=0;i<8;i++) { 
492 
idct4col(dest + i, 2 * line_size, block + i);

493 
idct4col(dest + line_size + i, 2 * line_size, block + 8 + i); 
494 
} 
495 
} 
496  
497 
/* 8x4 & 4x8 WMV2 IDCT */

498 
#undef CN_SHIFT

499 
#undef C_SHIFT

500 
#undef C_FIX

501 
#undef C1

502 
#undef C2

503 
#define CN_SHIFT 12 
504 
#define C_FIX(x) ((int)((x) * 1.414213562 * (1 << CN_SHIFT) + 0.5)) 
505 
#define C1 C_FIX(0.6532814824) 
506 
#define C2 C_FIX(0.2705980501) 
507 
#define C3 C_FIX(0.5) 
508 
#define C_SHIFT (4+1+12) 
509 
static inline void idct4col_add(uint8_t *dest, int line_size, const DCTELEM *col) 
510 
{ 
511 
int c0, c1, c2, c3, a0, a1, a2, a3;

512 
const uint8_t *cm = cropTbl + MAX_NEG_CROP;

513  
514 
a0 = col[8*0]; 
515 
a1 = col[8*1]; 
516 
a2 = col[8*2]; 
517 
a3 = col[8*3]; 
518 
c0 = (a0 + a2)*C3 + (1 << (C_SHIFT  1)); 
519 
c2 = (a0  a2)*C3 + (1 << (C_SHIFT  1)); 
520 
c1 = a1 * C1 + a3 * C2; 
521 
c3 = a1 * C2  a3 * C1; 
522 
dest[0] = cm[dest[0] + ((c0 + c1) >> C_SHIFT)]; 
523 
dest += line_size; 
524 
dest[0] = cm[dest[0] + ((c2 + c3) >> C_SHIFT)]; 
525 
dest += line_size; 
526 
dest[0] = cm[dest[0] + ((c2  c3) >> C_SHIFT)]; 
527 
dest += line_size; 
528 
dest[0] = cm[dest[0] + ((c0  c1) >> C_SHIFT)]; 
529 
} 
530  
531 
#define RN_SHIFT 15 
532 
#define R_FIX(x) ((int)((x) * 1.414213562 * (1 << RN_SHIFT) + 0.5)) 
533 
#define R1 R_FIX(0.6532814824) 
534 
#define R2 R_FIX(0.2705980501) 
535 
#define R3 R_FIX(0.5) 
536 
#define R_SHIFT 11 
537 
static inline void idct4row(DCTELEM *row) 
538 
{ 
539 
int c0, c1, c2, c3, a0, a1, a2, a3;

540 
//const uint8_t *cm = cropTbl + MAX_NEG_CROP;

541  
542 
a0 = row[0];

543 
a1 = row[1];

544 
a2 = row[2];

545 
a3 = row[3];

546 
c0 = (a0 + a2)*R3 + (1 << (R_SHIFT  1)); 
547 
c2 = (a0  a2)*R3 + (1 << (R_SHIFT  1)); 
548 
c1 = a1 * R1 + a3 * R2; 
549 
c3 = a1 * R2  a3 * R1; 
550 
row[0]= (c0 + c1) >> R_SHIFT;

551 
row[1]= (c2 + c3) >> R_SHIFT;

552 
row[2]= (c2  c3) >> R_SHIFT;

553 
row[3]= (c0  c1) >> R_SHIFT;

554 
} 
555  
556 
void simple_idct84_add(uint8_t *dest, int line_size, DCTELEM *block) 
557 
{ 
558 
int i;

559  
560 
/* IDCT8 on each line */

561 
for(i=0; i<4; i++) { 
562 
idctRowCondDC(block + i*8);

563 
} 
564  
565 
/* IDCT4 and store */

566 
for(i=0;i<8;i++) { 
567 
idct4col_add(dest + i, line_size, block + i); 
568 
} 
569 
} 
570  
571 
void simple_idct48_add(uint8_t *dest, int line_size, DCTELEM *block) 
572 
{ 
573 
int i;

574  
575 
/* IDCT4 on each line */

576 
for(i=0; i<8; i++) { 
577 
idct4row(block + i*8);

578 
} 
579  
580 
/* IDCT8 and store */

581 
for(i=0; i<4; i++){ 
582 
idctSparseColAdd(dest + i, line_size, block + i); 
583 
} 
584 
} 
585 