com32/lib/jpeg/rgb24.c

   1 /*
   2  * Small jpeg decoder library
   3  *
   4  * Copyright (c) 2006, Luc Saillard <luc@saillard.org>
   5  * All rights reserved.
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright notice,
  10  *  this list of conditions and the following disclaimer.
  11  *
  12  * - Redistributions in binary form must reproduce the above copyright notice,
  13  *  this list of conditions and the following disclaimer in the documentation
  14  *  and/or other materials provided with the distribution.
  15  *
  16  * - Neither the name of the author nor the names of its contributors may be
  17  *  used to endorse or promote products derived from this software without
  18  *  specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  30  * POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <stdint.h>
  38
  39 #include "tinyjpeg.h"
  40 #include "tinyjpeg-internal.h"
  41
  42 /*******************************************************************************
  43  *
  44  * Colorspace conversion routine
  45  *
  46  *
  47  * Note:
  48  * YCbCr is defined per CCIR 601-1, except that Cb and Cr are
  49  * normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
  50  * The conversion equations to be implemented are therefore
  51  *      R = Y                + 1.40200 * Cr
  52  *      G = Y - 0.34414 * Cb - 0.71414 * Cr
  53  *      B = Y + 1.77200 * Cb
  54  *
  55  ******************************************************************************/
  56 static unsigned char clamp(int i)
  57 {
  58   if (i<0)
  59     return 0;
  60   else if (i>255)
  61     return 255;
  62   else
  63     return i;
  64 }
  65
  66 /**
  67  *  YCrCb -> RGB24 (1x1)
  68  *  .---.
  69  *  | 1 |
  70  *  `---'
  71  */
  72 static void YCrCB_to_RGB24_1x1(struct jdec_private *priv)
  73 {
  74   const unsigned char *Y, *Cb, *Cr;
  75   unsigned char *p;
  76   int i,j;
  77   int offset_to_next_row;
  78
  79 #define SCALEBITS       10
  80 #define ONE_HALF        (1UL << (SCALEBITS-1))
  81 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
  82
  83   p = priv->plane[0];
  84   Y = priv->Y;
  85   Cb = priv->Cb;
  86   Cr = priv->Cr;
  87   offset_to_next_row = priv->bytes_per_row[0] - 8*3;
  88   for (i=0; i<8; i++) {
  89
  90     for (j=0;j<8;j++) {
  91
  92        int y, cb, cr;
  93        int add_r, add_g, add_b;
  94        int r, g , b;
  95
  96        y  = (*Y++) << SCALEBITS;
  97        cb = *Cb++ - 128;
  98        cr = *Cr++ - 128;
  99        add_r = FIX(1.40200) * cr + ONE_HALF;
 100        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 101        add_b = FIX(1.77200) * cb + ONE_HALF;
 102
 103        r = (y + add_r) >> SCALEBITS;
 104        *p++ = clamp(r);
 105        g = (y + add_g) >> SCALEBITS;
 106        *p++ = clamp(g);
 107        b = (y + add_b) >> SCALEBITS;
 108        *p++ = clamp(b);
 109
 110     }
 111
 112     p += offset_to_next_row;
 113   }
 114
 115 #undef SCALEBITS
 116 #undef ONE_HALF
 117 #undef FIX
 118
 119 }
 120
 121 /**
 122  *  YCrCb -> RGB24 (2x1)
 123  *  .-------.
 124  *  | 1 | 2 |
 125  *  `-------'
 126  */
 127 static void YCrCB_to_RGB24_2x1(struct jdec_private *priv)
 128 {
 129   const unsigned char *Y, *Cb, *Cr;
 130   unsigned char *p;
 131   int i,j;
 132   int offset_to_next_row;
 133
 134 #define SCALEBITS       10
 135 #define ONE_HALF        (1UL << (SCALEBITS-1))
 136 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 137
 138   p = priv->plane[0];
 139   Y = priv->Y;
 140   Cb = priv->Cb;
 141   Cr = priv->Cr;
 142   offset_to_next_row = priv->bytes_per_row[0] - 16*3;
 143   for (i=0; i<8; i++) {
 144
 145     for (j=0; j<8; j++) {
 146
 147        int y, cb, cr;
 148        int add_r, add_g, add_b;
 149        int r, g , b;
 150
 151        y  = (*Y++) << SCALEBITS;
 152        cb = *Cb++ - 128;
 153        cr = *Cr++ - 128;
 154        add_r = FIX(1.40200) * cr + ONE_HALF;
 155        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 156        add_b = FIX(1.77200) * cb + ONE_HALF;
 157
 158        r = (y + add_r) >> SCALEBITS;
 159        *p++ = clamp(r);
 160        g = (y + add_g) >> SCALEBITS;
 161        *p++ = clamp(g);
 162        b = (y + add_b) >> SCALEBITS;
 163        *p++ = clamp(b);
 164
 165        y  = (*Y++) << SCALEBITS;
 166        r = (y + add_r) >> SCALEBITS;
 167        *p++ = clamp(r);
 168        g = (y + add_g) >> SCALEBITS;
 169        *p++ = clamp(g);
 170        b = (y + add_b) >> SCALEBITS;
 171        *p++ = clamp(b);
 172
 173     }
 174
 175     p += offset_to_next_row;
 176   }
 177
 178 #undef SCALEBITS
 179 #undef ONE_HALF
 180 #undef FIX
 181
 182 }
 183
 184
 185 /**
 186  *  YCrCb -> RGB24 (1x2)
 187  *  .---.
 188  *  | 1 |
 189  *  |---|
 190  *  | 2 |
 191  *  `---'
 192  */
 193 static void YCrCB_to_RGB24_1x2(struct jdec_private *priv)
 194 {
 195   const unsigned char *Y, *Cb, *Cr;
 196   unsigned char *p, *p2;
 197   int i,j;
 198   int offset_to_next_row;
 199
 200 #define SCALEBITS       10
 201 #define ONE_HALF        (1UL << (SCALEBITS-1))
 202 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 203
 204   p = priv->plane[0];
 205   p2 = priv->plane[0] + priv->bytes_per_row[0];
 206   Y = priv->Y;
 207   Cb = priv->Cb;
 208   Cr = priv->Cr;
 209   offset_to_next_row = 2*priv->bytes_per_row[0] - 8*3;
 210   for (i=0; i<8; i++) {
 211
 212     for (j=0; j<8; j++) {
 213
 214        int y, cb, cr;
 215        int add_r, add_g, add_b;
 216        int r, g , b;
 217
 218        cb = *Cb++ - 128;
 219        cr = *Cr++ - 128;
 220        add_r = FIX(1.40200) * cr + ONE_HALF;
 221        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 222        add_b = FIX(1.77200) * cb + ONE_HALF;
 223
 224        y  = (*Y++) << SCALEBITS;
 225        r = (y + add_r) >> SCALEBITS;
 226        *p++ = clamp(r);
 227        g = (y + add_g) >> SCALEBITS;
 228        *p++ = clamp(g);
 229        b = (y + add_b) >> SCALEBITS;
 230        *p++ = clamp(b);
 231
 232        y  = (Y[8-1]) << SCALEBITS;
 233        r = (y + add_r) >> SCALEBITS;
 234        *p2++ = clamp(r);
 235        g = (y + add_g) >> SCALEBITS;
 236        *p2++ = clamp(g);
 237        b = (y + add_b) >> SCALEBITS;
 238        *p2++ = clamp(b);
 239
 240     }
 241     Y += 8;
 242     p += offset_to_next_row;
 243     p2 += offset_to_next_row;
 244   }
 245
 246 #undef SCALEBITS
 247 #undef ONE_HALF
 248 #undef FIX
 249
 250 }
 251
 252 /**
 253  *  YCrCb -> RGB24 (2x2)
 254  *  .-------.
 255  *  | 1 | 2 |
 256  *  |---+---|
 257  *  | 3 | 4 |
 258  *  `-------'
 259  */
 260 static void YCrCB_to_RGB24_2x2(struct jdec_private *priv)
 261 {
 262   const unsigned char *Y, *Cb, *Cr;
 263   unsigned char *p, *p2;
 264   int i,j;
 265   int offset_to_next_row;
 266
 267 #define SCALEBITS       10
 268 #define ONE_HALF        (1UL << (SCALEBITS-1))
 269 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 270
 271   p = priv->plane[0];
 272   p2 = priv->plane[0] + priv->bytes_per_row[0];
 273   Y = priv->Y;
 274   Cb = priv->Cb;
 275   Cr = priv->Cr;
 276   offset_to_next_row = 2*priv->bytes_per_row[0] - 16*3;
 277   for (i=0; i<8; i++) {
 278
 279     for (j=0;j<8;j++) {
 280
 281        int y, cb, cr;
 282        int add_r, add_g, add_b;
 283        int r, g , b;
 284
 285        cb = *Cb++ - 128;
 286        cr = *Cr++ - 128;
 287        add_r = FIX(1.40200) * cr + ONE_HALF;
 288        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 289        add_b = FIX(1.77200) * cb + ONE_HALF;
 290
 291        y  = (*Y++) << SCALEBITS;
 292        r = (y + add_r) >> SCALEBITS;
 293        *p++ = clamp(r);
 294        g = (y + add_g) >> SCALEBITS;
 295        *p++ = clamp(g);
 296        b = (y + add_b) >> SCALEBITS;
 297        *p++ = clamp(b);
 298
 299        y  = (*Y++) << SCALEBITS;
 300        r = (y + add_r) >> SCALEBITS;
 301        *p++ = clamp(r);
 302        g = (y + add_g) >> SCALEBITS;
 303        *p++ = clamp(g);
 304        b = (y + add_b) >> SCALEBITS;
 305        *p++ = clamp(b);
 306
 307        y  = (Y[16-2]) << SCALEBITS;
 308        r = (y + add_r) >> SCALEBITS;
 309        *p2++ = clamp(r);
 310        g = (y + add_g) >> SCALEBITS;
 311        *p2++ = clamp(g);
 312        b = (y + add_b) >> SCALEBITS;
 313        *p2++ = clamp(b);
 314
 315        y  = (Y[16-1]) << SCALEBITS;
 316        r = (y + add_r) >> SCALEBITS;
 317        *p2++ = clamp(r);
 318        g = (y + add_g) >> SCALEBITS;
 319        *p2++ = clamp(g);
 320        b = (y + add_b) >> SCALEBITS;
 321        *p2++ = clamp(b);
 322     }
 323     Y  += 16;
 324     p  += offset_to_next_row;
 325     p2 += offset_to_next_row;
 326   }
 327
 328 #undef SCALEBITS
 329 #undef ONE_HALF
 330 #undef FIX
 331
 332 }
 333
 334 static int initialize_rgb24(struct jdec_private *priv,
 335                             unsigned int *bytes_per_blocklines,
 336                             unsigned int *bytes_per_mcu)
 337 {
 338   if (priv->components[0] == NULL)
 339     priv->components[0] = (uint8_t *)malloc(priv->width * priv->height * 3);
 340   if (!priv->bytes_per_row[0])
 341     priv->bytes_per_row[0] = priv->width * 3;
 342
 343   bytes_per_blocklines[0] = priv->bytes_per_row[0];
 344   bytes_per_mcu[0] = 3*8;
 345
 346   return !priv->components[0];
 347 }
 348
 349 static const struct tinyjpeg_colorspace format_rgb24 =
 350   {
 351     {
 352       YCrCB_to_RGB24_1x1,
 353       YCrCB_to_RGB24_1x2,
 354       YCrCB_to_RGB24_2x1,
 355       YCrCB_to_RGB24_2x2,
 356     },
 357     tinyjpeg_decode_mcu_3comp_table,
 358     initialize_rgb24
 359   };
 360
 361 const tinyjpeg_colorspace_t TINYJPEG_FMT_RGB24 = &format_rgb24;