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			274 lines
		
	
	
	
		
			7.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			274 lines
		
	
	
	
		
			7.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * idct.c
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|  * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
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|  * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
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|  *
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|  * This file is part of mpeg2dec, a free MPEG-2 video stream decoder.
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|  * See http://libmpeg2.sourceforge.net/ for updates.
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|  *
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|  * mpeg2dec is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License as published by
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|  * the Free Software Foundation; either version 2 of the License, or
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|  * (at your option) any later version.
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|  *
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|  * mpeg2dec 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
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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|  *
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|  * $Id$
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|  * libmpeg2 sync history:
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|  * 2008-07-01 - CVS revision 1.36
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|  */
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| 
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| #include "plugin.h"
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| 
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| #include "mpeg2dec_config.h"
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| 
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| #include "mpeg2.h"
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| #include "attributes.h"
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| #include "mpeg2_internal.h"
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| 
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| #if defined(CPU_COLDFIRE) || defined (CPU_ARM)
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| #define IDCT_ASM
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| #endif
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| 
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| #ifndef IDCT_ASM
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| 
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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 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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| 
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| /*
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|  * In legal streams, the IDCT output should be between -384 and +384.
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|  * In corrupted streams, it is possible to force the IDCT output to go
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|  * to +-3826 - this is the worst case for a column IDCT where the
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|  * column inputs are 16-bit values.
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|  */
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| #define CLIP(i) \
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|     ({ typeof (i) _i = (i); \
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|        if ((_i & 0xff) != _i) \
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|            _i = ~(_i >> (8*sizeof(_i) - 1)); \
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|        _i; })
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| 
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| #if 0
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| #define BUTTERFLY(t0,t1,W0,W1,d0,d1) \
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|     do {                             \
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|         t0 = W0 * d0 + W1 * d1;      \
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|         t1 = W0 * d1 - W1 * d0;      \
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|     } while (0)
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| #else
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| #define BUTTERFLY(t0,t1,W0,W1,d0,d1) \
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|     do {                             \
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|         int tmp = W0 * (d0 + d1);    \
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|         t0 = tmp + (W1 - W0) * d1;   \
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|         t1 = tmp - (W1 + W0) * d0;   \
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|     } while (0)
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| #endif
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| 
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| static inline void idct_row (int16_t * const block)
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| {
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|     int d0, d1, d2, d3;
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|     int a0, a1, a2, a3, b0, b1, b2, b3;
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|     int t0, t1, t2, t3;
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| 
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|     /* shortcut */
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|     if (likely (!(block[1] | ((int32_t *)block)[1] | ((int32_t *)block)[2] |
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|                  ((int32_t *)block)[3])))
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|     {
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|         uint32_t tmp = (uint16_t) (block[0] >> 1);
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|         tmp |= tmp << 16;
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|         ((int32_t *)block)[0] = tmp;
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|         ((int32_t *)block)[1] = tmp;
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|         ((int32_t *)block)[2] = tmp;
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|         ((int32_t *)block)[3] = tmp;
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|         return;
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|     }
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| 
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|     d0 = (block[0] << 11) + 2048;
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|     d1 = block[1];
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|     d2 = block[2] << 11;
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|     d3 = block[3];
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|     t0 = d0 + d2;
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|     t1 = d0 - d2;
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|     BUTTERFLY (t2, t3, W6, W2, d3, d1);
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|     a0 = t0 + t2;
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|     a1 = t1 + t3;
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|     a2 = t1 - t3;
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|     a3 = t0 - t2;
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| 
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|     d0 = block[4];
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|     d1 = block[5];
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|     d2 = block[6];
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|     d3 = block[7];
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|     BUTTERFLY (t0, t1, W7, W1, d3, d0);
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|     BUTTERFLY (t2, t3, W3, W5, d1, d2);
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|     b0 = t0 + t2;
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|     b3 = t1 + t3;
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|     t0 -= t2;
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|     t1 -= t3;
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|     b1 = ((t0 + t1) >> 8) * 181;
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|     b2 = ((t0 - t1) >> 8) * 181;
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| 
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|     block[0] = (a0 + b0) >> 12;
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|     block[1] = (a1 + b1) >> 12;
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|     block[2] = (a2 + b2) >> 12;
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|     block[3] = (a3 + b3) >> 12;
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|     block[4] = (a3 - b3) >> 12;
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|     block[5] = (a2 - b2) >> 12;
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|     block[6] = (a1 - b1) >> 12;
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|     block[7] = (a0 - b0) >> 12;
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| }
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| 
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| static inline void idct_col (int16_t * const block)
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| {
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|     int d0, d1, d2, d3;
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|     int a0, a1, a2, a3, b0, b1, b2, b3;
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|     int t0, t1, t2, t3;
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| 
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|     d0 = (block[8*0] << 11) + 65536;
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|     d1 = block[8*1];
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|     d2 = block[8*2] << 11;
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|     d3 = block[8*3];
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|     t0 = d0 + d2;
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|     t1 = d0 - d2;
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|     BUTTERFLY (t2, t3, W6, W2, d3, d1);
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|     a0 = t0 + t2;
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|     a1 = t1 + t3;
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|     a2 = t1 - t3;
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|     a3 = t0 - t2;
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| 
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|     d0 = block[8*4];
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|     d1 = block[8*5];
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|     d2 = block[8*6];
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|     d3 = block[8*7];
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|     BUTTERFLY (t0, t1, W7, W1, d3, d0);
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|     BUTTERFLY (t2, t3, W3, W5, d1, d2);
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|     b0 = t0 + t2;
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|     b3 = t1 + t3;
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|     t0 -= t2;
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|     t1 -= t3;
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|     b1 = ((t0 + t1) >> 8) * 181;
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|     b2 = ((t0 - t1) >> 8) * 181;
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| 
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|     block[8*0] = (a0 + b0) >> 17;
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|     block[8*1] = (a1 + b1) >> 17;
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|     block[8*2] = (a2 + b2) >> 17;
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|     block[8*3] = (a3 + b3) >> 17;
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|     block[8*4] = (a3 - b3) >> 17;
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|     block[8*5] = (a2 - b2) >> 17;
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|     block[8*6] = (a1 - b1) >> 17;
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|     block[8*7] = (a0 - b0) >> 17;
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| }
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| 
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| void mpeg2_idct_copy (int16_t * block, uint8_t * dest,
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|                       const int stride)
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| {
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|     int i;
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| 
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|     for (i = 0; i < 8; i++)
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|         idct_row (block + 8 * i);
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| 
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|     for (i = 0; i < 8; i++)
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|         idct_col (block + i);
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| 
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|     do
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|     {
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|         dest[0] = CLIP (block[0]);
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|         dest[1] = CLIP (block[1]);
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|         dest[2] = CLIP (block[2]);
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|         dest[3] = CLIP (block[3]);
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|         dest[4] = CLIP (block[4]);
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|         dest[5] = CLIP (block[5]);
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|         dest[6] = CLIP (block[6]);
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|         dest[7] = CLIP (block[7]);
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| 
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|         ((int32_t *)block)[0] = 0;
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|         ((int32_t *)block)[1] = 0;
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|         ((int32_t *)block)[2] = 0;
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|         ((int32_t *)block)[3] = 0;
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| 
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|         dest += stride;
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|         block += 8;
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|     }
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|     while (--i);
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| }
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| 
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| void mpeg2_idct_add (const int last, int16_t * block,
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|                      uint8_t * dest, const int stride)
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| {
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|     int i;
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| 
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|     if (last != 129 || (block[0] & (7 << 4)) == (4 << 4))
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|     {
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|         for (i = 0; i < 8; i++)
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|             idct_row (block + 8 * i);
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| 
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|         for (i = 0; i < 8; i++)
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|             idct_col (block + i);
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| 
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|         do
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|         {
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|             dest[0] = CLIP (block[0] + dest[0]);
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|             dest[1] = CLIP (block[1] + dest[1]);
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|             dest[2] = CLIP (block[2] + dest[2]);
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|             dest[3] = CLIP (block[3] + dest[3]);
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|             dest[4] = CLIP (block[4] + dest[4]);
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|             dest[5] = CLIP (block[5] + dest[5]);
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|             dest[6] = CLIP (block[6] + dest[6]);
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|             dest[7] = CLIP (block[7] + dest[7]);
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| 
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|             ((int32_t *)block)[0] = 0;
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|             ((int32_t *)block)[1] = 0;
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|             ((int32_t *)block)[2] = 0;
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|             ((int32_t *)block)[3] = 0;
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| 
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|             dest += stride;
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|             block += 8;
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|         }
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|         while (--i);
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|     }
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|     else
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|     {
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|         int DC = (block[0] + 64) >> 7;
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|         block[0] = block[63] = 0;
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|         i = 8;
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| 
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|         do
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|         {
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|             dest[0] = CLIP (DC + dest[0]);
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|             dest[1] = CLIP (DC + dest[1]);
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|             dest[2] = CLIP (DC + dest[2]);
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|             dest[3] = CLIP (DC + dest[3]);
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|             dest[4] = CLIP (DC + dest[4]);
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|             dest[5] = CLIP (DC + dest[5]);
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|             dest[6] = CLIP (DC + dest[6]);
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|             dest[7] = CLIP (DC + dest[7]);
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|             dest += stride;
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|         }
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|         while (--i);
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|     }
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| }
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| 
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| #endif /* IDCT_ASM */
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| 
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| void mpeg2_idct_init (void)
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| {
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|     int i, j;
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| 
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|     for (i = 0; i < 64; i++)
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|     {
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|         j = default_mpeg2_scan_norm[i];
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|         mpeg2_scan_norm[i] = ((j & 0x36) >> 1) | ((j & 0x09) << 2);
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| 
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|         j = default_mpeg2_scan_alt[i];
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|         mpeg2_scan_alt[i] = ((j & 0x36) >> 1) | ((j & 0x09) << 2);
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|     }
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| }
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