| 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 "eaidct.h" |
| 29 | #include "libavutil/common.h" |
| 30 | |
| 31 | #define ASQRT 181 /* (1/sqrt(2))<<8 */ |
| 32 | #define A4 669 /* cos(pi/8)*sqrt(2)<<9 */ |
| 33 | #define A2 277 /* sin(pi/8)*sqrt(2)<<9 */ |
| 34 | #define A5 196 /* sin(pi/8)<<9 */ |
| 35 | |
| 36 | #define IDCT_TRANSFORM(dest,s0,s1,s2,s3,s4,s5,s6,s7,d0,d1,d2,d3,d4,d5,d6,d7,munge,src) {\ |
| 37 | const int a1 = (src)[s1] + (src)[s7]; \ |
| 38 | const int a7 = (src)[s1] - (src)[s7]; \ |
| 39 | const int a5 = (src)[s5] + (src)[s3]; \ |
| 40 | const int a3 = (src)[s5] - (src)[s3]; \ |
| 41 | const int a2 = (src)[s2] + (src)[s6]; \ |
| 42 | const int a6 = (ASQRT*((src)[s2] - (src)[s6]))>>8; \ |
| 43 | const int a0 = (src)[s0] + (src)[s4]; \ |
| 44 | const int a4 = (src)[s0] - (src)[s4]; \ |
| 45 | const int b0 = (((A4-A5)*a7 - A5*a3)>>9) + a1+a5; \ |
| 46 | const int b1 = (((A4-A5)*a7 - A5*a3)>>9) + ((ASQRT*(a1-a5))>>8); \ |
| 47 | const int b2 = (((A2+A5)*a3 + A5*a7)>>9) + ((ASQRT*(a1-a5))>>8); \ |
| 48 | const int b3 = ((A2+A5)*a3 + A5*a7)>>9; \ |
| 49 | (dest)[d0] = munge(a0+a2+a6+b0); \ |
| 50 | (dest)[d1] = munge(a4+a6 +b1); \ |
| 51 | (dest)[d2] = munge(a4-a6 +b2); \ |
| 52 | (dest)[d3] = munge(a0-a2-a6+b3); \ |
| 53 | (dest)[d4] = munge(a0-a2-a6-b3); \ |
| 54 | (dest)[d5] = munge(a4-a6 -b2); \ |
| 55 | (dest)[d6] = munge(a4+a6 -b1); \ |
| 56 | (dest)[d7] = munge(a0+a2+a6-b0); \ |
| 57 | } |
| 58 | /* end IDCT_TRANSFORM macro */ |
| 59 | |
| 60 | #define MUNGE_NONE(x) (x) |
| 61 | #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) |
| 62 | |
| 63 | #define MUNGE_8BIT(x) av_clip_uint8((x)>>4) |
| 64 | #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) |
| 65 | |
| 66 | static inline void ea_idct_col(int16_t *dest, const int16_t *src) { |
| 67 | if ((src[8]|src[16]|src[24]|src[32]|src[40]|src[48]|src[56])==0) { |
| 68 | dest[0] = |
| 69 | dest[8] = |
| 70 | dest[16] = |
| 71 | dest[24] = |
| 72 | dest[32] = |
| 73 | dest[40] = |
| 74 | dest[48] = |
| 75 | dest[56] = src[0]; |
| 76 | }else |
| 77 | IDCT_COL(dest, src); |
| 78 | } |
| 79 | |
| 80 | void ff_ea_idct_put_c(uint8_t *dest, int linesize, int16_t *block) { |
| 81 | int i; |
| 82 | int16_t temp[64]; |
| 83 | block[0] += 4; |
| 84 | for (i=0; i<8; i++) |
| 85 | ea_idct_col(&temp[i], &block[i]); |
| 86 | for (i=0; i<8; i++) |
| 87 | IDCT_ROW( (&dest[i*linesize]), (&temp[8*i]) ); |
| 88 | } |