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