1/* 2 * Simple IDCT 3 * 4 * Copyright (c) 2001 Michael Niedermayer <michaelni@gmx.at> 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23/** 24 * @file 25 * simpleidct in C. 26 */ 27 28#include "libavutil/intreadwrite.h" 29#include "avcodec.h" 30#include "mathops.h" 31#include "simple_idct.h" 32 33#define BIT_DEPTH 8 34#include "simple_idct_template.c" 35#undef BIT_DEPTH 36 37#define BIT_DEPTH 10 38#include "simple_idct_template.c" 39#undef BIT_DEPTH 40 41#define BIT_DEPTH 12 42#include "simple_idct_template.c" 43#undef BIT_DEPTH 44 45/* 2x4x8 idct */ 46 47#define CN_SHIFT 12 48#define C_FIX(x) ((int)((x) * (1 << CN_SHIFT) + 0.5)) 49#define C1 C_FIX(0.6532814824) 50#define C2 C_FIX(0.2705980501) 51 52/* row idct is multiple by 16 * sqrt(2.0), col idct4 is normalized, 53 and the butterfly must be multiplied by 0.5 * sqrt(2.0) */ 54#define C_SHIFT (4+1+12) 55 56static inline void idct4col_put(uint8_t *dest, int line_size, const int16_t *col) 57{ 58 int c0, c1, c2, c3, a0, a1, a2, a3; 59 60 a0 = col[8*0]; 61 a1 = col[8*2]; 62 a2 = col[8*4]; 63 a3 = col[8*6]; 64 c0 = ((a0 + a2) << (CN_SHIFT - 1)) + (1 << (C_SHIFT - 1)); 65 c2 = ((a0 - a2) << (CN_SHIFT - 1)) + (1 << (C_SHIFT - 1)); 66 c1 = a1 * C1 + a3 * C2; 67 c3 = a1 * C2 - a3 * C1; 68 dest[0] = av_clip_uint8((c0 + c1) >> C_SHIFT); 69 dest += line_size; 70 dest[0] = av_clip_uint8((c2 + c3) >> C_SHIFT); 71 dest += line_size; 72 dest[0] = av_clip_uint8((c2 - c3) >> C_SHIFT); 73 dest += line_size; 74 dest[0] = av_clip_uint8((c0 - c1) >> C_SHIFT); 75} 76 77#define BF(k) \ 78{\ 79 int a0, a1;\ 80 a0 = ptr[k];\ 81 a1 = ptr[8 + k];\ 82 ptr[k] = a0 + a1;\ 83 ptr[8 + k] = a0 - a1;\ 84} 85 86/* only used by DV codec. The input must be interlaced. 128 is added 87 to the pixels before clamping to avoid systematic error 88 (1024*sqrt(2)) offset would be needed otherwise. */ 89/* XXX: I think a 1.0/sqrt(2) normalization should be needed to 90 compensate the extra butterfly stage - I don't have the full DV 91 specification */ 92void ff_simple_idct248_put(uint8_t *dest, int line_size, int16_t *block) 93{ 94 int i; 95 int16_t *ptr; 96 97 /* butterfly */ 98 ptr = block; 99 for(i=0;i<4;i++) { 100 BF(0); 101 BF(1); 102 BF(2); 103 BF(3); 104 BF(4); 105 BF(5); 106 BF(6); 107 BF(7); 108 ptr += 2 * 8; 109 } 110 111 /* IDCT8 on each line */ 112 for(i=0; i<8; i++) { 113 idctRowCondDC_8(block + i*8, 0); 114 } 115 116 /* IDCT4 and store */ 117 for(i=0;i<8;i++) { 118 idct4col_put(dest + i, 2 * line_size, block + i); 119 idct4col_put(dest + line_size + i, 2 * line_size, block + 8 + i); 120 } 121} 122 123/* 8x4 & 4x8 WMV2 IDCT */ 124#undef CN_SHIFT 125#undef C_SHIFT 126#undef C_FIX 127#undef C1 128#undef C2 129#define CN_SHIFT 12 130#define C_FIX(x) ((int)((x) * 1.414213562 * (1 << CN_SHIFT) + 0.5)) 131#define C1 C_FIX(0.6532814824) 132#define C2 C_FIX(0.2705980501) 133#define C3 C_FIX(0.5) 134#define C_SHIFT (4+1+12) 135static inline void idct4col_add(uint8_t *dest, int line_size, const int16_t *col) 136{ 137 int c0, c1, c2, c3, a0, a1, a2, a3; 138 139 a0 = col[8*0]; 140 a1 = col[8*1]; 141 a2 = col[8*2]; 142 a3 = col[8*3]; 143 c0 = (a0 + a2)*C3 + (1 << (C_SHIFT - 1)); 144 c2 = (a0 - a2)*C3 + (1 << (C_SHIFT - 1)); 145 c1 = a1 * C1 + a3 * C2; 146 c3 = a1 * C2 - a3 * C1; 147 dest[0] = av_clip_uint8(dest[0] + ((c0 + c1) >> C_SHIFT)); 148 dest += line_size; 149 dest[0] = av_clip_uint8(dest[0] + ((c2 + c3) >> C_SHIFT)); 150 dest += line_size; 151 dest[0] = av_clip_uint8(dest[0] + ((c2 - c3) >> C_SHIFT)); 152 dest += line_size; 153 dest[0] = av_clip_uint8(dest[0] + ((c0 - c1) >> C_SHIFT)); 154} 155 156#define RN_SHIFT 15 157#define R_FIX(x) ((int)((x) * 1.414213562 * (1 << RN_SHIFT) + 0.5)) 158#define R1 R_FIX(0.6532814824) 159#define R2 R_FIX(0.2705980501) 160#define R3 R_FIX(0.5) 161#define R_SHIFT 11 162static inline void idct4row(int16_t *row) 163{ 164 int c0, c1, c2, c3, a0, a1, a2, a3; 165 166 a0 = row[0]; 167 a1 = row[1]; 168 a2 = row[2]; 169 a3 = row[3]; 170 c0 = (a0 + a2)*R3 + (1 << (R_SHIFT - 1)); 171 c2 = (a0 - a2)*R3 + (1 << (R_SHIFT - 1)); 172 c1 = a1 * R1 + a3 * R2; 173 c3 = a1 * R2 - a3 * R1; 174 row[0]= (c0 + c1) >> R_SHIFT; 175 row[1]= (c2 + c3) >> R_SHIFT; 176 row[2]= (c2 - c3) >> R_SHIFT; 177 row[3]= (c0 - c1) >> R_SHIFT; 178} 179 180void ff_simple_idct84_add(uint8_t *dest, int line_size, int16_t *block) 181{ 182 int i; 183 184 /* IDCT8 on each line */ 185 for(i=0; i<4; i++) { 186 idctRowCondDC_8(block + i*8, 0); 187 } 188 189 /* IDCT4 and store */ 190 for(i=0;i<8;i++) { 191 idct4col_add(dest + i, line_size, block + i); 192 } 193} 194 195void ff_simple_idct48_add(uint8_t *dest, int line_size, int16_t *block) 196{ 197 int i; 198 199 /* IDCT4 on each line */ 200 for(i=0; i<8; i++) { 201 idct4row(block + i*8); 202 } 203 204 /* IDCT8 and store */ 205 for(i=0; i<4; i++){ 206 idctSparseColAdd_8(dest + i, line_size, block + i); 207 } 208} 209 210void ff_simple_idct44_add(uint8_t *dest, int line_size, int16_t *block) 211{ 212 int i; 213 214 /* IDCT4 on each line */ 215 for(i=0; i<4; i++) { 216 idct4row(block + i*8); 217 } 218 219 /* IDCT4 and store */ 220 for(i=0; i<4; i++){ 221 idct4col_add(dest + i, line_size, block + i); 222 } 223} 224 225void ff_prores_idct(int16_t *block, const int16_t *qmat) 226{ 227 int i; 228 229 for (i = 0; i < 64; i++) 230 block[i] *= qmat[i]; 231 232 for (i = 0; i < 8; i++) 233 idctRowCondDC_10(block + i*8, 2); 234 235 for (i = 0; i < 8; i++) { 236 block[i] += 8192; 237 idctSparseCol_10(block + i); 238 } 239} 240