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88 lines
3.0 KiB
C
88 lines
3.0 KiB
C
/*
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* Electronic Arts TGQ/TQI/MAD IDCT algorithm
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* Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
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*
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* This file is part of Libav.
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*
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* Libav 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 2.1 of the License, or (at your option) any later version.
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*
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* Libav 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 Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* Electronic Arts TGQ/TQI/MAD IDCT algorithm
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* @author Peter Ross <pross@xvid.org>
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*/
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#include "dsputil.h"
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#define ASQRT 181 /* (1/sqrt(2))<<8 */
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#define A4 669 /* cos(pi/8)*sqrt(2)<<9 */
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#define A2 277 /* sin(pi/8)*sqrt(2)<<9 */
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#define A5 196 /* sin(pi/8)<<9 */
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#define IDCT_TRANSFORM(dest,s0,s1,s2,s3,s4,s5,s6,s7,d0,d1,d2,d3,d4,d5,d6,d7,munge,src) {\
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const int a1 = (src)[s1] + (src)[s7]; \
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const int a7 = (src)[s1] - (src)[s7]; \
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const int a5 = (src)[s5] + (src)[s3]; \
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const int a3 = (src)[s5] - (src)[s3]; \
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const int a2 = (src)[s2] + (src)[s6]; \
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const int a6 = (ASQRT*((src)[s2] - (src)[s6]))>>8; \
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const int a0 = (src)[s0] + (src)[s4]; \
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const int a4 = (src)[s0] - (src)[s4]; \
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const int b0 = (((A4-A5)*a7 - A5*a3)>>9) + a1+a5; \
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const int b1 = (((A4-A5)*a7 - A5*a3)>>9) + ((ASQRT*(a1-a5))>>8); \
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const int b2 = (((A2+A5)*a3 + A5*a7)>>9) + ((ASQRT*(a1-a5))>>8); \
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const int b3 = ((A2+A5)*a3 + A5*a7)>>9; \
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(dest)[d0] = munge(a0+a2+a6+b0); \
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(dest)[d1] = munge(a4+a6 +b1); \
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(dest)[d2] = munge(a4-a6 +b2); \
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(dest)[d3] = munge(a0-a2-a6+b3); \
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(dest)[d4] = munge(a0-a2-a6-b3); \
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(dest)[d5] = munge(a4-a6 -b2); \
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(dest)[d6] = munge(a4+a6 -b1); \
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(dest)[d7] = munge(a0+a2+a6-b0); \
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}
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/* end IDCT_TRANSFORM macro */
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#define MUNGE_NONE(x) (x)
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#define IDCT_COL(dest,src) IDCT_TRANSFORM(dest,0,8,16,24,32,40,48,56,0,8,16,24,32,40,48,56,MUNGE_NONE,src)
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#define MUNGE_8BIT(x) av_clip_uint8((x)>>4)
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#define IDCT_ROW(dest,src) IDCT_TRANSFORM(dest,0,1,2,3,4,5,6,7,0,1,2,3,4,5,6,7,MUNGE_8BIT,src)
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static inline void ea_idct_col(DCTELEM *dest, const DCTELEM *src) {
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if ((src[8]|src[16]|src[24]|src[32]|src[40]|src[48]|src[56])==0) {
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dest[0] =
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dest[8] =
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dest[16] =
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dest[24] =
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dest[32] =
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dest[40] =
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dest[48] =
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dest[56] = src[0];
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}else
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IDCT_COL(dest, src);
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}
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void ff_ea_idct_put_c(uint8_t *dest, int linesize, DCTELEM *block) {
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int i;
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DCTELEM temp[64];
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block[0] += 4;
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for (i=0; i<8; i++)
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ea_idct_col(&temp[i], &block[i]);
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for (i=0; i<8; i++)
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IDCT_ROW( (&dest[i*linesize]), (&temp[8*i]) );
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}
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