media/ffvpx/libavcodec/simple_idct.c

   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 "mathops.h"
  30 #include "simple_idct.h"
  31
  32 #define IN_IDCT_DEPTH 16
  33
  34 #define BIT_DEPTH 8
  35 #include "simple_idct_template.c"
  36 #undef BIT_DEPTH
  37
  38 #define BIT_DEPTH 10
  39 #include "simple_idct_template.c"
  40
  41 #define EXTRA_SHIFT  2
  42 #include "simple_idct_template.c"
  43
  44 #undef EXTRA_SHIFT
  45 #undef BIT_DEPTH
  46
  47 #define BIT_DEPTH 12
  48 #include "simple_idct_template.c"
  49 #undef BIT_DEPTH
  50 #undef IN_IDCT_DEPTH
  51
  52 #define IN_IDCT_DEPTH 32
  53 #define BIT_DEPTH 10
  54 #include "simple_idct_template.c"
  55 #undef BIT_DEPTH
  56 #undef IN_IDCT_DEPTH
  57
  58 /* 2x4x8 idct */
  59
  60 #define CN_SHIFT 12
  61 #define C_FIX(x) ((int)((x) * (1 << CN_SHIFT) + 0.5))
  62 #define C1 C_FIX(0.6532814824)
  63 #define C2 C_FIX(0.2705980501)
  64
  65 /* row idct is multiple by 16 * sqrt(2.0), col idct4 is normalized,
  66    and the butterfly must be multiplied by 0.5 * sqrt(2.0) */
  67 #define C_SHIFT (4+1+12)
  68
  69 static inline void idct4col_put(uint8_t *dest, ptrdiff_t line_size, const int16_t *col)
  70 {
  71     int c0, c1, c2, c3, a0, a1, a2, a3;
  72
  73     a0 = col[8*0];
  74     a1 = col[8*2];
  75     a2 = col[8*4];
  76     a3 = col[8*6];
  77     c0 = ((a0 + a2) * (1 << CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
  78     c2 = ((a0 - a2) * (1 << CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
  79     c1 = a1 * C1 + a3 * C2;
  80     c3 = a1 * C2 - a3 * C1;
  81     dest[0] = av_clip_uint8((c0 + c1) >> C_SHIFT);
  82     dest += line_size;
  83     dest[0] = av_clip_uint8((c2 + c3) >> C_SHIFT);
  84     dest += line_size;
  85     dest[0] = av_clip_uint8((c2 - c3) >> C_SHIFT);
  86     dest += line_size;
  87     dest[0] = av_clip_uint8((c0 - c1) >> C_SHIFT);
  88 }
  89
  90 #define BF(k) \
  91 {\
  92     int a0, a1;\
  93     a0 = ptr[k];\
  94     a1 = ptr[8 + k];\
  95     ptr[k] = a0 + a1;\
  96     ptr[8 + k] = a0 - a1;\
  97 }
  98
  99 /* only used by DV codec. The input must be interlaced. 128 is added
 100    to the pixels before clamping to avoid systematic error
 101    (1024*sqrt(2)) offset would be needed otherwise. */
 102 /* XXX: I think a 1.0/sqrt(2) normalization should be needed to
 103    compensate the extra butterfly stage - I don't have the full DV
 104    specification */
 105 void ff_simple_idct248_put(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
 106 {
 107     int i;
 108     int16_t *ptr;
 109
 110     /* butterfly */
 111     ptr = block;
 112     for(i=0;i<4;i++) {
 113         BF(0);
 114         BF(1);
 115         BF(2);
 116         BF(3);
 117         BF(4);
 118         BF(5);
 119         BF(6);
 120         BF(7);
 121         ptr += 2 * 8;
 122     }
 123
 124     /* IDCT8 on each line */
 125     for(i=0; i<8; i++) {
 126         idctRowCondDC_int16_8bit(block + i*8, 0);
 127     }
 128
 129     /* IDCT4 and store */
 130     for(i=0;i<8;i++) {
 131         idct4col_put(dest + i, 2 * line_size, block + i);
 132         idct4col_put(dest + line_size + i, 2 * line_size, block + 8 + i);
 133     }
 134 }
 135
 136 /* 8x4 & 4x8 WMV2 IDCT */
 137 #undef CN_SHIFT
 138 #undef C_SHIFT
 139 #undef C_FIX
 140 #undef C1
 141 #undef C2
 142 #define CN_SHIFT 12
 143 #define C_FIX(x) ((int)((x) * M_SQRT2 * (1 << CN_SHIFT) + 0.5))
 144 #define C1 C_FIX(0.6532814824)
 145 #define C2 C_FIX(0.2705980501)
 146 #define C3 C_FIX(0.5)
 147 #define C_SHIFT (4+1+12)
 148 static inline void idct4col_add(uint8_t *dest, ptrdiff_t line_size, const int16_t *col)
 149 {
 150     int c0, c1, c2, c3, a0, a1, a2, a3;
 151
 152     a0 = col[8*0];
 153     a1 = col[8*1];
 154     a2 = col[8*2];
 155     a3 = col[8*3];
 156     c0 = (a0 + a2)*C3 + (1 << (C_SHIFT - 1));
 157     c2 = (a0 - a2)*C3 + (1 << (C_SHIFT - 1));
 158     c1 = a1 * C1 + a3 * C2;
 159     c3 = a1 * C2 - a3 * C1;
 160     dest[0] = av_clip_uint8(dest[0] + ((c0 + c1) >> C_SHIFT));
 161     dest += line_size;
 162     dest[0] = av_clip_uint8(dest[0] + ((c2 + c3) >> C_SHIFT));
 163     dest += line_size;
 164     dest[0] = av_clip_uint8(dest[0] + ((c2 - c3) >> C_SHIFT));
 165     dest += line_size;
 166     dest[0] = av_clip_uint8(dest[0] + ((c0 - c1) >> C_SHIFT));
 167 }
 168
 169 #define RN_SHIFT 15
 170 #define R_FIX(x) ((int)((x) * M_SQRT2 * (1 << RN_SHIFT) + 0.5))
 171 #define R1 R_FIX(0.6532814824)
 172 #define R2 R_FIX(0.2705980501)
 173 #define R3 R_FIX(0.5)
 174 #define R_SHIFT 11
 175 static inline void idct4row(int16_t *row)
 176 {
 177     unsigned c0, c1, c2, c3;
 178     int a0, a1, a2, a3;
 179
 180     a0 = row[0];
 181     a1 = row[1];
 182     a2 = row[2];
 183     a3 = row[3];
 184     c0 = (a0 + a2)*R3 + (1 << (R_SHIFT - 1));
 185     c2 = (a0 - a2)*R3 + (1 << (R_SHIFT - 1));
 186     c1 = a1 * R1 + a3 * R2;
 187     c3 = a1 * R2 - a3 * R1;
 188     row[0]= (c0 + c1) >> R_SHIFT;
 189     row[1]= (c2 + c3) >> R_SHIFT;
 190     row[2]= (c2 - c3) >> R_SHIFT;
 191     row[3]= (c0 - c1) >> R_SHIFT;
 192 }
 193
 194 void ff_simple_idct84_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
 195 {
 196     int i;
 197
 198     /* IDCT8 on each line */
 199     for(i=0; i<4; i++) {
 200         idctRowCondDC_int16_8bit(block + i*8, 0);
 201     }
 202
 203     /* IDCT4 and store */
 204     for(i=0;i<8;i++) {
 205         idct4col_add(dest + i, line_size, block + i);
 206     }
 207 }
 208
 209 void ff_simple_idct48_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
 210 {
 211     int i;
 212
 213     /* IDCT4 on each line */
 214     for(i=0; i<8; i++) {
 215         idct4row(block + i*8);
 216     }
 217
 218     /* IDCT8 and store */
 219     for(i=0; i<4; i++){
 220         idctSparseColAdd_int16_8bit(dest + i, line_size, block + i);
 221     }
 222 }
 223
 224 void ff_simple_idct44_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
 225 {
 226     int i;
 227
 228     /* IDCT4 on each line */
 229     for(i=0; i<4; i++) {
 230         idct4row(block + i*8);
 231     }
 232
 233     /* IDCT4 and store */
 234     for(i=0; i<4; i++){
 235         idct4col_add(dest + i, line_size, block + i);
 236     }
 237 }
 238
 239 void ff_prores_idct_10(int16_t *block, const int16_t *qmat)
 240 {
 241     int i;
 242
 243     for (i = 0; i < 64; i++)
 244         block[i] *= qmat[i];
 245
 246     for (i = 0; i < 8; i++)
 247         idctRowCondDC_extrashift_10(block + i*8, 2);
 248
 249     for (i = 0; i < 8; i++) {
 250         block[i] += 8192;
 251         idctSparseCol_extrashift_10(block + i);
 252     }
 253 }
 254
 255 void ff_prores_idct_12(int16_t *block, const int16_t *qmat)
 256 {
 257     int i;
 258
 259     for (i = 0; i < 64; i++)
 260         block[i] *= qmat[i];
 261
 262     for (i = 0; i < 8; i++)
 263         idctRowCondDC_int16_12bit(block + i*8, 0);
 264
 265     for (i = 0; i < 8; i++) {
 266         block[i] += 8192;
 267         idctSparseCol_int16_12bit(block + i);
 268     }
 269 }