Libav
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00001 /* 00002 * Floating point AAN IDCT 00003 * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at> 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * FFmpeg is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with FFmpeg; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 #include "faanidct.h" 00022 00023 /* To allow switching to double. */ 00024 #define FLOAT float 00025 00026 #define B0 1.0000000000000000000000 00027 #define B1 1.3870398453221474618216 // cos(pi*1/16)sqrt(2) 00028 #define B2 1.3065629648763765278566 // cos(pi*2/16)sqrt(2) 00029 #define B3 1.1758756024193587169745 // cos(pi*3/16)sqrt(2) 00030 #define B4 1.0000000000000000000000 // cos(pi*4/16)sqrt(2) 00031 #define B5 0.7856949583871021812779 // cos(pi*5/16)sqrt(2) 00032 #define B6 0.5411961001461969843997 // cos(pi*6/16)sqrt(2) 00033 #define B7 0.2758993792829430123360 // cos(pi*7/16)sqrt(2) 00034 00035 #define A4 0.70710678118654752438 // cos(pi*4/16) 00036 #define A2 0.92387953251128675613 // cos(pi*2/16) 00037 00038 static const FLOAT prescale[64]={ 00039 B0*B0/8, B0*B1/8, B0*B2/8, B0*B3/8, B0*B4/8, B0*B5/8, B0*B6/8, B0*B7/8, 00040 B1*B0/8, B1*B1/8, B1*B2/8, B1*B3/8, B1*B4/8, B1*B5/8, B1*B6/8, B1*B7/8, 00041 B2*B0/8, B2*B1/8, B2*B2/8, B2*B3/8, B2*B4/8, B2*B5/8, B2*B6/8, B2*B7/8, 00042 B3*B0/8, B3*B1/8, B3*B2/8, B3*B3/8, B3*B4/8, B3*B5/8, B3*B6/8, B3*B7/8, 00043 B4*B0/8, B4*B1/8, B4*B2/8, B4*B3/8, B4*B4/8, B4*B5/8, B4*B6/8, B4*B7/8, 00044 B5*B0/8, B5*B1/8, B5*B2/8, B5*B3/8, B5*B4/8, B5*B5/8, B5*B6/8, B5*B7/8, 00045 B6*B0/8, B6*B1/8, B6*B2/8, B6*B3/8, B6*B4/8, B6*B5/8, B6*B6/8, B6*B7/8, 00046 B7*B0/8, B7*B1/8, B7*B2/8, B7*B3/8, B7*B4/8, B7*B5/8, B7*B6/8, B7*B7/8, 00047 }; 00048 00049 static inline void p8idct(DCTELEM data[64], FLOAT temp[64], uint8_t *dest, int stride, int x, int y, int type){ 00050 int i; 00051 FLOAT av_unused tmp0; 00052 FLOAT s04, d04, s17, d17, s26, d26, s53, d53; 00053 FLOAT os07, os16, os25, os34; 00054 FLOAT od07, od16, od25, od34; 00055 00056 for(i=0; i<y*8; i+=y){ 00057 s17= temp[1*x + i] + temp[7*x + i]; 00058 d17= temp[1*x + i] - temp[7*x + i]; 00059 s53= temp[5*x + i] + temp[3*x + i]; 00060 d53= temp[5*x + i] - temp[3*x + i]; 00061 00062 od07= s17 + s53; 00063 od25= (s17 - s53)*(2*A4); 00064 00065 #if 0 //these 2 are equivalent 00066 tmp0= (d17 + d53)*(2*A2); 00067 od34= d17*( 2*B6) - tmp0; 00068 od16= d53*(-2*B2) + tmp0; 00069 #else 00070 od34= d17*(2*(B6-A2)) - d53*(2*A2); 00071 od16= d53*(2*(A2-B2)) + d17*(2*A2); 00072 #endif 00073 00074 od16 -= od07; 00075 od25 -= od16; 00076 od34 += od25; 00077 00078 s26 = temp[2*x + i] + temp[6*x + i]; 00079 d26 = temp[2*x + i] - temp[6*x + i]; 00080 d26*= 2*A4; 00081 d26-= s26; 00082 00083 s04= temp[0*x + i] + temp[4*x + i]; 00084 d04= temp[0*x + i] - temp[4*x + i]; 00085 00086 os07= s04 + s26; 00087 os34= s04 - s26; 00088 os16= d04 + d26; 00089 os25= d04 - d26; 00090 00091 if(type==0){ 00092 temp[0*x + i]= os07 + od07; 00093 temp[7*x + i]= os07 - od07; 00094 temp[1*x + i]= os16 + od16; 00095 temp[6*x + i]= os16 - od16; 00096 temp[2*x + i]= os25 + od25; 00097 temp[5*x + i]= os25 - od25; 00098 temp[3*x + i]= os34 - od34; 00099 temp[4*x + i]= os34 + od34; 00100 }else if(type==1){ 00101 data[0*x + i]= lrintf(os07 + od07); 00102 data[7*x + i]= lrintf(os07 - od07); 00103 data[1*x + i]= lrintf(os16 + od16); 00104 data[6*x + i]= lrintf(os16 - od16); 00105 data[2*x + i]= lrintf(os25 + od25); 00106 data[5*x + i]= lrintf(os25 - od25); 00107 data[3*x + i]= lrintf(os34 - od34); 00108 data[4*x + i]= lrintf(os34 + od34); 00109 }else if(type==2){ 00110 dest[0*stride + i]= av_clip_uint8(((int)dest[0*stride + i]) + lrintf(os07 + od07)); 00111 dest[7*stride + i]= av_clip_uint8(((int)dest[7*stride + i]) + lrintf(os07 - od07)); 00112 dest[1*stride + i]= av_clip_uint8(((int)dest[1*stride + i]) + lrintf(os16 + od16)); 00113 dest[6*stride + i]= av_clip_uint8(((int)dest[6*stride + i]) + lrintf(os16 - od16)); 00114 dest[2*stride + i]= av_clip_uint8(((int)dest[2*stride + i]) + lrintf(os25 + od25)); 00115 dest[5*stride + i]= av_clip_uint8(((int)dest[5*stride + i]) + lrintf(os25 - od25)); 00116 dest[3*stride + i]= av_clip_uint8(((int)dest[3*stride + i]) + lrintf(os34 - od34)); 00117 dest[4*stride + i]= av_clip_uint8(((int)dest[4*stride + i]) + lrintf(os34 + od34)); 00118 }else{ 00119 dest[0*stride + i]= av_clip_uint8(lrintf(os07 + od07)); 00120 dest[7*stride + i]= av_clip_uint8(lrintf(os07 - od07)); 00121 dest[1*stride + i]= av_clip_uint8(lrintf(os16 + od16)); 00122 dest[6*stride + i]= av_clip_uint8(lrintf(os16 - od16)); 00123 dest[2*stride + i]= av_clip_uint8(lrintf(os25 + od25)); 00124 dest[5*stride + i]= av_clip_uint8(lrintf(os25 - od25)); 00125 dest[3*stride + i]= av_clip_uint8(lrintf(os34 - od34)); 00126 dest[4*stride + i]= av_clip_uint8(lrintf(os34 + od34)); 00127 } 00128 } 00129 } 00130 00131 void ff_faanidct(DCTELEM block[64]){ 00132 FLOAT temp[64]; 00133 int i; 00134 00135 emms_c(); 00136 00137 for(i=0; i<64; i++) 00138 temp[i] = block[i] * prescale[i]; 00139 00140 p8idct(block, temp, NULL, 0, 1, 8, 0); 00141 p8idct(block, temp, NULL, 0, 8, 1, 1); 00142 } 00143 00144 void ff_faanidct_add(uint8_t *dest, int line_size, DCTELEM block[64]){ 00145 FLOAT temp[64]; 00146 int i; 00147 00148 emms_c(); 00149 00150 for(i=0; i<64; i++) 00151 temp[i] = block[i] * prescale[i]; 00152 00153 p8idct(block, temp, NULL, 0, 1, 8, 0); 00154 p8idct(NULL , temp, dest, line_size, 8, 1, 2); 00155 } 00156 00157 void ff_faanidct_put(uint8_t *dest, int line_size, DCTELEM block[64]){ 00158 FLOAT temp[64]; 00159 int i; 00160 00161 emms_c(); 00162 00163 for(i=0; i<64; i++) 00164 temp[i] = block[i] * prescale[i]; 00165 00166 p8idct(block, temp, NULL, 0, 1, 8, 0); 00167 p8idct(NULL , temp, dest, line_size, 8, 1, 3); 00168 }