yading@10: /*
yading@10:  * Electronic Arts TGQ/TQI/MAD IDCT algorithm
yading@10:  * Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * Electronic Arts TGQ/TQI/MAD IDCT algorithm
yading@10:  * @author Peter Ross <pross@xvid.org>
yading@10:  */
yading@10: 
yading@10: #include "eaidct.h"
yading@10: #include "libavutil/common.h"
yading@10: 
yading@10: #define ASQRT 181 /* (1/sqrt(2))<<8 */
yading@10: #define A4    669 /* cos(pi/8)*sqrt(2)<<9 */
yading@10: #define A2    277 /* sin(pi/8)*sqrt(2)<<9 */
yading@10: #define A5    196 /* sin(pi/8)<<9 */
yading@10: 
yading@10: #define IDCT_TRANSFORM(dest,s0,s1,s2,s3,s4,s5,s6,s7,d0,d1,d2,d3,d4,d5,d6,d7,munge,src) {\
yading@10:     const int a1 = (src)[s1] + (src)[s7]; \
yading@10:     const int a7 = (src)[s1] - (src)[s7]; \
yading@10:     const int a5 = (src)[s5] + (src)[s3]; \
yading@10:     const int a3 = (src)[s5] - (src)[s3]; \
yading@10:     const int a2 = (src)[s2] + (src)[s6]; \
yading@10:     const int a6 = (ASQRT*((src)[s2] - (src)[s6]))>>8; \
yading@10:     const int a0 = (src)[s0] + (src)[s4]; \
yading@10:     const int a4 = (src)[s0] - (src)[s4]; \
yading@10:     const int b0 = (((A4-A5)*a7 - A5*a3)>>9) + a1+a5; \
yading@10:     const int b1 = (((A4-A5)*a7 - A5*a3)>>9) + ((ASQRT*(a1-a5))>>8); \
yading@10:     const int b2 = (((A2+A5)*a3 + A5*a7)>>9) + ((ASQRT*(a1-a5))>>8); \
yading@10:     const int b3 =  ((A2+A5)*a3 + A5*a7)>>9; \
yading@10:     (dest)[d0] = munge(a0+a2+a6+b0); \
yading@10:     (dest)[d1] = munge(a4+a6   +b1); \
yading@10:     (dest)[d2] = munge(a4-a6   +b2); \
yading@10:     (dest)[d3] = munge(a0-a2-a6+b3); \
yading@10:     (dest)[d4] = munge(a0-a2-a6-b3); \
yading@10:     (dest)[d5] = munge(a4-a6   -b2); \
yading@10:     (dest)[d6] = munge(a4+a6   -b1); \
yading@10:     (dest)[d7] = munge(a0+a2+a6-b0); \
yading@10: }
yading@10: /* end IDCT_TRANSFORM macro */
yading@10: 
yading@10: #define MUNGE_NONE(x) (x)
yading@10: #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)
yading@10: 
yading@10: #define MUNGE_8BIT(x) av_clip_uint8((x)>>4)
yading@10: #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)
yading@10: 
yading@10: static inline void ea_idct_col(int16_t *dest, const int16_t *src) {
yading@10:     if ((src[8]|src[16]|src[24]|src[32]|src[40]|src[48]|src[56])==0) {
yading@10:         dest[0]  =
yading@10:         dest[8]  =
yading@10:         dest[16] =
yading@10:         dest[24] =
yading@10:         dest[32] =
yading@10:         dest[40] =
yading@10:         dest[48] =
yading@10:         dest[56] = src[0];
yading@10:     }else
yading@10:         IDCT_COL(dest, src);
yading@10: }
yading@10: 
yading@10: void ff_ea_idct_put_c(uint8_t *dest, int linesize, int16_t *block) {
yading@10:     int i;
yading@10:     int16_t temp[64];
yading@10:     block[0] += 4;
yading@10:     for (i=0; i<8; i++)
yading@10:         ea_idct_col(&temp[i], &block[i]);
yading@10:     for (i=0; i<8; i++)
yading@10:         IDCT_ROW( (&dest[i*linesize]), (&temp[8*i]) );
yading@10: }