1/* 2 * Electronic Arts TGQ/TQI/MAD IDCT algorithm 3 * Copyright (c) 2007-2008 Peter Ross <pross@xvid.org> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * Electronic Arts TGQ/TQI/MAD IDCT algorithm 25 * @author Peter Ross <pross@xvid.org> 26 */ 27 28#include "dsputil.h" 29 30#define ASQRT 181 /* (1/sqrt(2))<<8 */ 31#define A4 669 /* cos(pi/8)*sqrt(2)<<9 */ 32#define A2 277 /* sin(pi/8)*sqrt(2)<<9 */ 33#define A5 196 /* sin(pi/8)<<9 */ 34 35#define IDCT_TRANSFORM(dest,s0,s1,s2,s3,s4,s5,s6,s7,d0,d1,d2,d3,d4,d5,d6,d7,munge,src) {\ 36 const int a1 = (src)[s1] + (src)[s7]; \ 37 const int a7 = (src)[s1] - (src)[s7]; \ 38 const int a5 = (src)[s5] + (src)[s3]; \ 39 const int a3 = (src)[s5] - (src)[s3]; \ 40 const int a2 = (src)[s2] + (src)[s6]; \ 41 const int a6 = (ASQRT*((src)[s2] - (src)[s6]))>>8; \ 42 const int a0 = (src)[s0] + (src)[s4]; \ 43 const int a4 = (src)[s0] - (src)[s4]; \ 44 const int b0 = (((A4-A5)*a7 - A5*a3)>>9) + a1+a5; \ 45 const int b1 = (((A4-A5)*a7 - A5*a3)>>9) + ((ASQRT*(a1-a5))>>8); \ 46 const int b2 = (((A2+A5)*a3 + A5*a7)>>9) + ((ASQRT*(a1-a5))>>8); \ 47 const int b3 = ((A2+A5)*a3 + A5*a7)>>9; \ 48 (dest)[d0] = munge(a0+a2+a6+b0); \ 49 (dest)[d1] = munge(a4+a6 +b1); \ 50 (dest)[d2] = munge(a4-a6 +b2); \ 51 (dest)[d3] = munge(a0-a2-a6+b3); \ 52 (dest)[d4] = munge(a0-a2-a6-b3); \ 53 (dest)[d5] = munge(a4-a6 -b2); \ 54 (dest)[d6] = munge(a4+a6 -b1); \ 55 (dest)[d7] = munge(a0+a2+a6-b0); \ 56} 57/* end IDCT_TRANSFORM macro */ 58 59#define MUNGE_NONE(x) (x) 60#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) 61 62#define MUNGE_8BIT(x) av_clip_uint8((x)>>4) 63#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) 64 65static inline void ea_idct_col(DCTELEM *dest, const DCTELEM *src) { 66 if ((src[8]|src[16]|src[24]|src[32]|src[40]|src[48]|src[56])==0) { 67 dest[0] = 68 dest[8] = 69 dest[16] = 70 dest[24] = 71 dest[32] = 72 dest[40] = 73 dest[48] = 74 dest[56] = src[0]; 75 }else 76 IDCT_COL(dest, src); 77} 78 79void ff_ea_idct_put_c(uint8_t *dest, int linesize, DCTELEM *block) { 80 int i; 81 DCTELEM temp[64]; 82 block[0] += 4; 83 for (i=0; i<8; i++) 84 ea_idct_col(&temp[i], &block[i]); 85 for (i=0; i<8; i++) 86 IDCT_ROW( (&dest[i*linesize]), (&temp[8*i]) ); 87} 88