| 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. */ |
| 25 | #define 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 | |
| 39 | static const FLOAT prescale[64]={ |
| 40 | B0*B0/8, B0*B1/8, B0*B2/8, B0*B3/8, B0*B4/8, B0*B5/8, B0*B6/8, B0*B7/8, |
| 41 | B1*B0/8, B1*B1/8, B1*B2/8, B1*B3/8, B1*B4/8, B1*B5/8, B1*B6/8, B1*B7/8, |
| 42 | B2*B0/8, B2*B1/8, B2*B2/8, B2*B3/8, B2*B4/8, B2*B5/8, B2*B6/8, B2*B7/8, |
| 43 | B3*B0/8, B3*B1/8, B3*B2/8, B3*B3/8, B3*B4/8, B3*B5/8, B3*B6/8, B3*B7/8, |
| 44 | B4*B0/8, B4*B1/8, B4*B2/8, B4*B3/8, B4*B4/8, B4*B5/8, B4*B6/8, B4*B7/8, |
| 45 | B5*B0/8, B5*B1/8, B5*B2/8, B5*B3/8, B5*B4/8, B5*B5/8, B5*B6/8, B5*B7/8, |
| 46 | B6*B0/8, B6*B1/8, B6*B2/8, B6*B3/8, B6*B4/8, B6*B5/8, B6*B6/8, B6*B7/8, |
| 47 | B7*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 | |
| 50 | static inline void p8idct(int16_t data[64], FLOAT temp[64], uint8_t *dest, int stride, int x, int y, int type){ |
| 51 | int i; |
| 52 | FLOAT s04, d04, s17, d17, s26, d26, s53, d53; |
| 53 | FLOAT os07, os16, os25, os34; |
| 54 | FLOAT od07, od16, od25, od34; |
| 55 | |
| 56 | for(i=0; i<y*8; i+=y){ |
| 57 | s17= temp[1*x + i] + temp[7*x + i]; |
| 58 | d17= temp[1*x + i] - temp[7*x + i]; |
| 59 | s53= temp[5*x + i] + temp[3*x + i]; |
| 60 | d53= temp[5*x + i] - temp[3*x + i]; |
| 61 | |
| 62 | od07= s17 + s53; |
| 63 | od25= (s17 - s53)*(2*A4); |
| 64 | |
| 65 | #if 0 //these 2 are equivalent |
| 66 | { |
| 67 | FLOAT tmp0; |
| 68 | tmp0 = (d17 + d53) * (2 * A2); |
| 69 | od34 = d17 * (2 * B6) - tmp0; |
| 70 | od16 = d53 * (-2 * B2) + tmp0; |
| 71 | } |
| 72 | #else |
| 73 | od34= d17*(2*(B6-A2)) - d53*(2*A2); |
| 74 | od16= d53*(2*(A2-B2)) + d17*(2*A2); |
| 75 | #endif |
| 76 | |
| 77 | od16 -= od07; |
| 78 | od25 -= od16; |
| 79 | od34 += od25; |
| 80 | |
| 81 | s26 = temp[2*x + i] + temp[6*x + i]; |
| 82 | d26 = temp[2*x + i] - temp[6*x + i]; |
| 83 | d26*= 2*A4; |
| 84 | d26-= s26; |
| 85 | |
| 86 | s04= temp[0*x + i] + temp[4*x + i]; |
| 87 | d04= temp[0*x + i] - temp[4*x + i]; |
| 88 | |
| 89 | os07= s04 + s26; |
| 90 | os34= s04 - s26; |
| 91 | os16= d04 + d26; |
| 92 | os25= d04 - d26; |
| 93 | |
| 94 | if(type==0){ |
| 95 | temp[0*x + i]= os07 + od07; |
| 96 | temp[7*x + i]= os07 - od07; |
| 97 | temp[1*x + i]= os16 + od16; |
| 98 | temp[6*x + i]= os16 - od16; |
| 99 | temp[2*x + i]= os25 + od25; |
| 100 | temp[5*x + i]= os25 - od25; |
| 101 | temp[3*x + i]= os34 - od34; |
| 102 | temp[4*x + i]= os34 + od34; |
| 103 | }else if(type==1){ |
| 104 | data[0*x + i]= lrintf(os07 + od07); |
| 105 | data[7*x + i]= lrintf(os07 - od07); |
| 106 | data[1*x + i]= lrintf(os16 + od16); |
| 107 | data[6*x + i]= lrintf(os16 - od16); |
| 108 | data[2*x + i]= lrintf(os25 + od25); |
| 109 | data[5*x + i]= lrintf(os25 - od25); |
| 110 | data[3*x + i]= lrintf(os34 - od34); |
| 111 | data[4*x + i]= lrintf(os34 + od34); |
| 112 | }else if(type==2){ |
| 113 | dest[0*stride + i]= av_clip_uint8(((int)dest[0*stride + i]) + lrintf(os07 + od07)); |
| 114 | dest[7*stride + i]= av_clip_uint8(((int)dest[7*stride + i]) + lrintf(os07 - od07)); |
| 115 | dest[1*stride + i]= av_clip_uint8(((int)dest[1*stride + i]) + lrintf(os16 + od16)); |
| 116 | dest[6*stride + i]= av_clip_uint8(((int)dest[6*stride + i]) + lrintf(os16 - od16)); |
| 117 | dest[2*stride + i]= av_clip_uint8(((int)dest[2*stride + i]) + lrintf(os25 + od25)); |
| 118 | dest[5*stride + i]= av_clip_uint8(((int)dest[5*stride + i]) + lrintf(os25 - od25)); |
| 119 | dest[3*stride + i]= av_clip_uint8(((int)dest[3*stride + i]) + lrintf(os34 - od34)); |
| 120 | dest[4*stride + i]= av_clip_uint8(((int)dest[4*stride + i]) + lrintf(os34 + od34)); |
| 121 | }else{ |
| 122 | dest[0*stride + i]= av_clip_uint8(lrintf(os07 + od07)); |
| 123 | dest[7*stride + i]= av_clip_uint8(lrintf(os07 - od07)); |
| 124 | dest[1*stride + i]= av_clip_uint8(lrintf(os16 + od16)); |
| 125 | dest[6*stride + i]= av_clip_uint8(lrintf(os16 - od16)); |
| 126 | dest[2*stride + i]= av_clip_uint8(lrintf(os25 + od25)); |
| 127 | dest[5*stride + i]= av_clip_uint8(lrintf(os25 - od25)); |
| 128 | dest[3*stride + i]= av_clip_uint8(lrintf(os34 - od34)); |
| 129 | dest[4*stride + i]= av_clip_uint8(lrintf(os34 + od34)); |
| 130 | } |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | void ff_faanidct(int16_t block[64]){ |
| 135 | FLOAT temp[64]; |
| 136 | int i; |
| 137 | |
| 138 | emms_c(); |
| 139 | |
| 140 | for(i=0; i<64; i++) |
| 141 | temp[i] = block[i] * prescale[i]; |
| 142 | |
| 143 | p8idct(block, temp, NULL, 0, 1, 8, 0); |
| 144 | p8idct(block, temp, NULL, 0, 8, 1, 1); |
| 145 | } |
| 146 | |
| 147 | void ff_faanidct_add(uint8_t *dest, int line_size, int16_t block[64]){ |
| 148 | FLOAT temp[64]; |
| 149 | int i; |
| 150 | |
| 151 | emms_c(); |
| 152 | |
| 153 | for(i=0; i<64; i++) |
| 154 | temp[i] = block[i] * prescale[i]; |
| 155 | |
| 156 | p8idct(block, temp, NULL, 0, 1, 8, 0); |
| 157 | p8idct(NULL , temp, dest, line_size, 8, 1, 2); |
| 158 | } |
| 159 | |
| 160 | void ff_faanidct_put(uint8_t *dest, int line_size, int16_t block[64]){ |
| 161 | FLOAT temp[64]; |
| 162 | int i; |
| 163 | |
| 164 | emms_c(); |
| 165 | |
| 166 | for(i=0; i<64; i++) |
| 167 | temp[i] = block[i] * prescale[i]; |
| 168 | |
| 169 | p8idct(block, temp, NULL, 0, 1, 8, 0); |
| 170 | p8idct(NULL , temp, dest, line_size, 8, 1, 3); |
| 171 | } |