1/* 2 * H.264 IDCT 3 * Copyright (c) 2004 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 22/** 23 * @file libavcodec/h264idct.c 24 * H.264 IDCT. 25 * @author Michael Niedermayer <michaelni@gmx.at> 26 */ 27 28#include "dsputil.h" 29 30static av_always_inline void idct_internal(uint8_t *dst, DCTELEM *block, int stride, int block_stride, int shift, int add){ 31 int i; 32 uint8_t *cm = ff_cropTbl + MAX_NEG_CROP; 33 34 block[0] += 1<<(shift-1); 35 36 for(i=0; i<4; i++){ 37 const int z0= block[0 + block_stride*i] + block[2 + block_stride*i]; 38 const int z1= block[0 + block_stride*i] - block[2 + block_stride*i]; 39 const int z2= (block[1 + block_stride*i]>>1) - block[3 + block_stride*i]; 40 const int z3= block[1 + block_stride*i] + (block[3 + block_stride*i]>>1); 41 42 block[0 + block_stride*i]= z0 + z3; 43 block[1 + block_stride*i]= z1 + z2; 44 block[2 + block_stride*i]= z1 - z2; 45 block[3 + block_stride*i]= z0 - z3; 46 } 47 48 for(i=0; i<4; i++){ 49 const int z0= block[i + block_stride*0] + block[i + block_stride*2]; 50 const int z1= block[i + block_stride*0] - block[i + block_stride*2]; 51 const int z2= (block[i + block_stride*1]>>1) - block[i + block_stride*3]; 52 const int z3= block[i + block_stride*1] + (block[i + block_stride*3]>>1); 53 54 dst[i + 0*stride]= cm[ add*dst[i + 0*stride] + ((z0 + z3) >> shift) ]; 55 dst[i + 1*stride]= cm[ add*dst[i + 1*stride] + ((z1 + z2) >> shift) ]; 56 dst[i + 2*stride]= cm[ add*dst[i + 2*stride] + ((z1 - z2) >> shift) ]; 57 dst[i + 3*stride]= cm[ add*dst[i + 3*stride] + ((z0 - z3) >> shift) ]; 58 } 59} 60 61void ff_h264_idct_add_c(uint8_t *dst, DCTELEM *block, int stride){ 62 idct_internal(dst, block, stride, 4, 6, 1); 63} 64 65void ff_h264_lowres_idct_add_c(uint8_t *dst, int stride, DCTELEM *block){ 66 idct_internal(dst, block, stride, 8, 3, 1); 67} 68 69void ff_h264_lowres_idct_put_c(uint8_t *dst, int stride, DCTELEM *block){ 70 idct_internal(dst, block, stride, 8, 3, 0); 71} 72 73void ff_h264_idct8_add_c(uint8_t *dst, DCTELEM *block, int stride){ 74 int i; 75 uint8_t *cm = ff_cropTbl + MAX_NEG_CROP; 76 77 block[0] += 32; 78 79 for( i = 0; i < 8; i++ ) 80 { 81 const int a0 = block[0+i*8] + block[4+i*8]; 82 const int a2 = block[0+i*8] - block[4+i*8]; 83 const int a4 = (block[2+i*8]>>1) - block[6+i*8]; 84 const int a6 = (block[6+i*8]>>1) + block[2+i*8]; 85 86 const int b0 = a0 + a6; 87 const int b2 = a2 + a4; 88 const int b4 = a2 - a4; 89 const int b6 = a0 - a6; 90 91 const int a1 = -block[3+i*8] + block[5+i*8] - block[7+i*8] - (block[7+i*8]>>1); 92 const int a3 = block[1+i*8] + block[7+i*8] - block[3+i*8] - (block[3+i*8]>>1); 93 const int a5 = -block[1+i*8] + block[7+i*8] + block[5+i*8] + (block[5+i*8]>>1); 94 const int a7 = block[3+i*8] + block[5+i*8] + block[1+i*8] + (block[1+i*8]>>1); 95 96 const int b1 = (a7>>2) + a1; 97 const int b3 = a3 + (a5>>2); 98 const int b5 = (a3>>2) - a5; 99 const int b7 = a7 - (a1>>2); 100 101 block[0+i*8] = b0 + b7; 102 block[7+i*8] = b0 - b7; 103 block[1+i*8] = b2 + b5; 104 block[6+i*8] = b2 - b5; 105 block[2+i*8] = b4 + b3; 106 block[5+i*8] = b4 - b3; 107 block[3+i*8] = b6 + b1; 108 block[4+i*8] = b6 - b1; 109 } 110 for( i = 0; i < 8; i++ ) 111 { 112 const int a0 = block[i+0*8] + block[i+4*8]; 113 const int a2 = block[i+0*8] - block[i+4*8]; 114 const int a4 = (block[i+2*8]>>1) - block[i+6*8]; 115 const int a6 = (block[i+6*8]>>1) + block[i+2*8]; 116 117 const int b0 = a0 + a6; 118 const int b2 = a2 + a4; 119 const int b4 = a2 - a4; 120 const int b6 = a0 - a6; 121 122 const int a1 = -block[i+3*8] + block[i+5*8] - block[i+7*8] - (block[i+7*8]>>1); 123 const int a3 = block[i+1*8] + block[i+7*8] - block[i+3*8] - (block[i+3*8]>>1); 124 const int a5 = -block[i+1*8] + block[i+7*8] + block[i+5*8] + (block[i+5*8]>>1); 125 const int a7 = block[i+3*8] + block[i+5*8] + block[i+1*8] + (block[i+1*8]>>1); 126 127 const int b1 = (a7>>2) + a1; 128 const int b3 = a3 + (a5>>2); 129 const int b5 = (a3>>2) - a5; 130 const int b7 = a7 - (a1>>2); 131 132 dst[i + 0*stride] = cm[ dst[i + 0*stride] + ((b0 + b7) >> 6) ]; 133 dst[i + 1*stride] = cm[ dst[i + 1*stride] + ((b2 + b5) >> 6) ]; 134 dst[i + 2*stride] = cm[ dst[i + 2*stride] + ((b4 + b3) >> 6) ]; 135 dst[i + 3*stride] = cm[ dst[i + 3*stride] + ((b6 + b1) >> 6) ]; 136 dst[i + 4*stride] = cm[ dst[i + 4*stride] + ((b6 - b1) >> 6) ]; 137 dst[i + 5*stride] = cm[ dst[i + 5*stride] + ((b4 - b3) >> 6) ]; 138 dst[i + 6*stride] = cm[ dst[i + 6*stride] + ((b2 - b5) >> 6) ]; 139 dst[i + 7*stride] = cm[ dst[i + 7*stride] + ((b0 - b7) >> 6) ]; 140 } 141} 142 143// assumes all AC coefs are 0 144void ff_h264_idct_dc_add_c(uint8_t *dst, DCTELEM *block, int stride){ 145 int i, j; 146 uint8_t *cm = ff_cropTbl + MAX_NEG_CROP; 147 int dc = (block[0] + 32) >> 6; 148 for( j = 0; j < 4; j++ ) 149 { 150 for( i = 0; i < 4; i++ ) 151 dst[i] = cm[ dst[i] + dc ]; 152 dst += stride; 153 } 154} 155 156void ff_h264_idct8_dc_add_c(uint8_t *dst, DCTELEM *block, int stride){ 157 int i, j; 158 uint8_t *cm = ff_cropTbl + MAX_NEG_CROP; 159 int dc = (block[0] + 32) >> 6; 160 for( j = 0; j < 8; j++ ) 161 { 162 for( i = 0; i < 8; i++ ) 163 dst[i] = cm[ dst[i] + dc ]; 164 dst += stride; 165 } 166} 167 168//FIXME this table is a duplicate from h264data.h, and will be removed once the tables from, h264 have been split 169static const uint8_t scan8[16 + 2*4]={ 170 4+1*8, 5+1*8, 4+2*8, 5+2*8, 171 6+1*8, 7+1*8, 6+2*8, 7+2*8, 172 4+3*8, 5+3*8, 4+4*8, 5+4*8, 173 6+3*8, 7+3*8, 6+4*8, 7+4*8, 174 1+1*8, 2+1*8, 175 1+2*8, 2+2*8, 176 1+4*8, 2+4*8, 177 1+5*8, 2+5*8, 178}; 179 180void ff_h264_idct_add16_c(uint8_t *dst, const int *block_offset, DCTELEM *block, int stride, const uint8_t nnzc[6*8]){ 181 int i; 182 for(i=0; i<16; i++){ 183 int nnz = nnzc[ scan8[i] ]; 184 if(nnz){ 185 if(nnz==1 && block[i*16]) ff_h264_idct_dc_add_c(dst + block_offset[i], block + i*16, stride); 186 else idct_internal (dst + block_offset[i], block + i*16, stride, 4, 6, 1); 187 } 188 } 189} 190 191void ff_h264_idct_add16intra_c(uint8_t *dst, const int *block_offset, DCTELEM *block, int stride, const uint8_t nnzc[6*8]){ 192 int i; 193 for(i=0; i<16; i++){ 194 if(nnzc[ scan8[i] ]) idct_internal (dst + block_offset[i], block + i*16, stride, 4, 6, 1); 195 else if(block[i*16]) ff_h264_idct_dc_add_c(dst + block_offset[i], block + i*16, stride); 196 } 197} 198 199void ff_h264_idct8_add4_c(uint8_t *dst, const int *block_offset, DCTELEM *block, int stride, const uint8_t nnzc[6*8]){ 200 int i; 201 for(i=0; i<16; i+=4){ 202 int nnz = nnzc[ scan8[i] ]; 203 if(nnz){ 204 if(nnz==1 && block[i*16]) ff_h264_idct8_dc_add_c(dst + block_offset[i], block + i*16, stride); 205 else ff_h264_idct8_add_c (dst + block_offset[i], block + i*16, stride); 206 } 207 } 208} 209 210void ff_h264_idct_add8_c(uint8_t **dest, const int *block_offset, DCTELEM *block, int stride, const uint8_t nnzc[6*8]){ 211 int i; 212 for(i=16; i<16+8; i++){ 213 if(nnzc[ scan8[i] ]) 214 ff_h264_idct_add_c (dest[(i&4)>>2] + block_offset[i], block + i*16, stride); 215 else if(block[i*16]) 216 ff_h264_idct_dc_add_c(dest[(i&4)>>2] + block_offset[i], block + i*16, stride); 217 } 218} 219