1/* 2 * Floating point AAN IDCT 3 * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at> 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#include "faanidct.h" 22#include "libavutil/common.h" 23 24/* To allow switching to double. */ 25typedef float FLOAT; 26 27#define B0 1.0000000000000000000000 28#define B1 1.3870398453221474618216 // cos(pi*1/16)sqrt(2) 29#define B2 1.3065629648763765278566 // cos(pi*2/16)sqrt(2) 30#define B3 1.1758756024193587169745 // cos(pi*3/16)sqrt(2) 31#define B4 1.0000000000000000000000 // cos(pi*4/16)sqrt(2) 32#define B5 0.7856949583871021812779 // cos(pi*5/16)sqrt(2) 33#define B6 0.5411961001461969843997 // cos(pi*6/16)sqrt(2) 34#define B7 0.2758993792829430123360 // cos(pi*7/16)sqrt(2) 35 36#define A4 0.70710678118654752438 // cos(pi*4/16) 37#define A2 0.92387953251128675613 // cos(pi*2/16) 38 39static const FLOAT prescale[64]={ 40B0*B0/8, B0*B1/8, B0*B2/8, B0*B3/8, B0*B4/8, B0*B5/8, B0*B6/8, B0*B7/8, 41B1*B0/8, B1*B1/8, B1*B2/8, B1*B3/8, B1*B4/8, B1*B5/8, B1*B6/8, B1*B7/8, 42B2*B0/8, B2*B1/8, B2*B2/8, B2*B3/8, B2*B4/8, B2*B5/8, B2*B6/8, B2*B7/8, 43B3*B0/8, B3*B1/8, B3*B2/8, B3*B3/8, B3*B4/8, B3*B5/8, B3*B6/8, B3*B7/8, 44B4*B0/8, B4*B1/8, B4*B2/8, B4*B3/8, B4*B4/8, B4*B5/8, B4*B6/8, B4*B7/8, 45B5*B0/8, B5*B1/8, B5*B2/8, B5*B3/8, B5*B4/8, B5*B5/8, B5*B6/8, B5*B7/8, 46B6*B0/8, B6*B1/8, B6*B2/8, B6*B3/8, B6*B4/8, B6*B5/8, B6*B6/8, B6*B7/8, 47B7*B0/8, B7*B1/8, B7*B2/8, B7*B3/8, B7*B4/8, B7*B5/8, B7*B6/8, B7*B7/8, 48}; 49 50static inline void p8idct(int16_t data[64], FLOAT temp[64], uint8_t *dest, 51 ptrdiff_t stride, int x, int y, int type) 52{ 53 int i; 54 FLOAT s04, d04, s17, d17, s26, d26, s53, d53; 55 FLOAT os07, os16, os25, os34; 56 FLOAT od07, od16, od25, od34; 57 58 for(i=0; i<y*8; i+=y){ 59 s17= temp[1*x + i] + temp[7*x + i]; 60 d17= temp[1*x + i] - temp[7*x + i]; 61 s53= temp[5*x + i] + temp[3*x + i]; 62 d53= temp[5*x + i] - temp[3*x + i]; 63 64 od07= s17 + s53; 65 od25= (s17 - s53)*(2*A4); 66 67 od34= d17*(2*(B6-A2)) - d53*(2*A2); 68 od16= d53*(2*(A2-B2)) + d17*(2*A2); 69 70 od16 -= od07; 71 od25 -= od16; 72 od34 += od25; 73 74 s26 = temp[2*x + i] + temp[6*x + i]; 75 d26 = temp[2*x + i] - temp[6*x + i]; 76 d26*= 2*A4; 77 d26-= s26; 78 79 s04= temp[0*x + i] + temp[4*x + i]; 80 d04= temp[0*x + i] - temp[4*x + i]; 81 82 os07= s04 + s26; 83 os34= s04 - s26; 84 os16= d04 + d26; 85 os25= d04 - d26; 86 87 if(type==0){ 88 temp[0*x + i]= os07 + od07; 89 temp[7*x + i]= os07 - od07; 90 temp[1*x + i]= os16 + od16; 91 temp[6*x + i]= os16 - od16; 92 temp[2*x + i]= os25 + od25; 93 temp[5*x + i]= os25 - od25; 94 temp[3*x + i]= os34 - od34; 95 temp[4*x + i]= os34 + od34; 96 }else if(type==1){ 97 data[0*x + i]= lrintf(os07 + od07); 98 data[7*x + i]= lrintf(os07 - od07); 99 data[1*x + i]= lrintf(os16 + od16); 100 data[6*x + i]= lrintf(os16 - od16); 101 data[2*x + i]= lrintf(os25 + od25); 102 data[5*x + i]= lrintf(os25 - od25); 103 data[3*x + i]= lrintf(os34 - od34); 104 data[4*x + i]= lrintf(os34 + od34); 105 }else if(type==2){ 106 dest[0*stride + i]= av_clip_uint8(((int)dest[0*stride + i]) + lrintf(os07 + od07)); 107 dest[7*stride + i]= av_clip_uint8(((int)dest[7*stride + i]) + lrintf(os07 - od07)); 108 dest[1*stride + i]= av_clip_uint8(((int)dest[1*stride + i]) + lrintf(os16 + od16)); 109 dest[6*stride + i]= av_clip_uint8(((int)dest[6*stride + i]) + lrintf(os16 - od16)); 110 dest[2*stride + i]= av_clip_uint8(((int)dest[2*stride + i]) + lrintf(os25 + od25)); 111 dest[5*stride + i]= av_clip_uint8(((int)dest[5*stride + i]) + lrintf(os25 - od25)); 112 dest[3*stride + i]= av_clip_uint8(((int)dest[3*stride + i]) + lrintf(os34 - od34)); 113 dest[4*stride + i]= av_clip_uint8(((int)dest[4*stride + i]) + lrintf(os34 + od34)); 114 }else{ 115 dest[0*stride + i]= av_clip_uint8(lrintf(os07 + od07)); 116 dest[7*stride + i]= av_clip_uint8(lrintf(os07 - od07)); 117 dest[1*stride + i]= av_clip_uint8(lrintf(os16 + od16)); 118 dest[6*stride + i]= av_clip_uint8(lrintf(os16 - od16)); 119 dest[2*stride + i]= av_clip_uint8(lrintf(os25 + od25)); 120 dest[5*stride + i]= av_clip_uint8(lrintf(os25 - od25)); 121 dest[3*stride + i]= av_clip_uint8(lrintf(os34 - od34)); 122 dest[4*stride + i]= av_clip_uint8(lrintf(os34 + od34)); 123 } 124 } 125} 126 127void ff_faanidct(int16_t block[64]){ 128 FLOAT temp[64]; 129 int i; 130 131 emms_c(); 132 133 for(i=0; i<64; i++) 134 temp[i] = block[i] * prescale[i]; 135 136 p8idct(block, temp, NULL, 0, 1, 8, 0); 137 p8idct(block, temp, NULL, 0, 8, 1, 1); 138} 139 140void ff_faanidct_add(uint8_t *dest, ptrdiff_t line_size, int16_t block[64]) 141{ 142 FLOAT temp[64]; 143 int i; 144 145 emms_c(); 146 147 for(i=0; i<64; i++) 148 temp[i] = block[i] * prescale[i]; 149 150 p8idct(block, temp, NULL, 0, 1, 8, 0); 151 p8idct(NULL , temp, dest, line_size, 8, 1, 2); 152} 153 154void ff_faanidct_put(uint8_t *dest, ptrdiff_t line_size, int16_t block[64]) 155{ 156 FLOAT temp[64]; 157 int i; 158 159 emms_c(); 160 161 for(i=0; i<64; i++) 162 temp[i] = block[i] * prescale[i]; 163 164 p8idct(block, temp, NULL, 0, 1, 8, 0); 165 p8idct(NULL , temp, dest, line_size, 8, 1, 3); 166} 167