com32/lib/jpeg/rgba32.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 -> RGBA32 (1x1)
  68  *  .---.
  69  *  | 1 |
  70  *  `---'
  71  */
  72 static void YCrCB_to_RGBA32_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*4;
  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, a;
  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        a = 255;
 110        *p++ = a;
 111     }
 112
 113     p += offset_to_next_row;
 114   }
 115
 116 #undef SCALEBITS
 117 #undef ONE_HALF
 118 #undef FIX
 119
 120 }
 121
 122 /**
 123  *  YCrCb -> RGBA32 (2x1)
 124  *  .-------.
 125  *  | 1 | 2 |
 126  *  `-------'
 127  */
 128 static void YCrCB_to_RGBA32_2x1(struct jdec_private *priv)
 129 {
 130   const unsigned char *Y, *Cb, *Cr;
 131   unsigned char *p;
 132   int i,j;
 133   int offset_to_next_row;
 134
 135 #define SCALEBITS       10
 136 #define ONE_HALF        (1UL << (SCALEBITS-1))
 137 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 138
 139   p = priv->plane[0];
 140   Y = priv->Y;
 141   Cb = priv->Cb;
 142   Cr = priv->Cr;
 143   offset_to_next_row = priv->bytes_per_row[0] - 16*4;
 144   for (i=0; i<8; i++) {
 145
 146     for (j=0; j<8; j++) {
 147
 148        int y, cb, cr;
 149        int add_r, add_g, add_b;
 150        int r, g , b, a;
 151
 152        y  = (*Y++) << SCALEBITS;
 153        cb = *Cb++ - 128;
 154        cr = *Cr++ - 128;
 155        add_r = FIX(1.40200) * cr + ONE_HALF;
 156        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 157        add_b = FIX(1.77200) * cb + ONE_HALF;
 158
 159        r = (y + add_r) >> SCALEBITS;
 160        *p++ = clamp(r);
 161        g = (y + add_g) >> SCALEBITS;
 162        *p++ = clamp(g);
 163        b = (y + add_b) >> SCALEBITS;
 164        *p++ = clamp(b);
 165        a = 255;
 166        *p++ = a;
 167
 168        y  = (*Y++) << SCALEBITS;
 169        r = (y + add_r) >> SCALEBITS;
 170        *p++ = clamp(r);
 171        g = (y + add_g) >> SCALEBITS;
 172        *p++ = clamp(g);
 173        b = (y + add_b) >> SCALEBITS;
 174        *p++ = clamp(b);
 175        a = 255;
 176        *p++ = a;
 177     }
 178
 179     p += offset_to_next_row;
 180   }
 181
 182 #undef SCALEBITS
 183 #undef ONE_HALF
 184 #undef FIX
 185
 186 }
 187
 188
 189 /**
 190  *  YCrCb -> RGBA32 (1x2)
 191  *  .---.
 192  *  | 1 |
 193  *  |---|
 194  *  | 2 |
 195  *  `---'
 196  */
 197 static void YCrCB_to_RGBA32_1x2(struct jdec_private *priv)
 198 {
 199   const unsigned char *Y, *Cb, *Cr;
 200   unsigned char *p, *p2;
 201   int i,j;
 202   int offset_to_next_row;
 203
 204 #define SCALEBITS       10
 205 #define ONE_HALF        (1UL << (SCALEBITS-1))
 206 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 207
 208   p = priv->plane[0];
 209   p2 = priv->plane[0] + priv->bytes_per_row[0];
 210   Y = priv->Y;
 211   Cb = priv->Cb;
 212   Cr = priv->Cr;
 213   offset_to_next_row = 2*priv->bytes_per_row[0] - 8*4;
 214   for (i=0; i<8; i++) {
 215
 216     for (j=0; j<8; j++) {
 217
 218        int y, cb, cr;
 219        int add_r, add_g, add_b;
 220        int r, g , b, a;
 221
 222        cb = *Cb++ - 128;
 223        cr = *Cr++ - 128;
 224        add_r = FIX(1.40200) * cr + ONE_HALF;
 225        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 226        add_b = FIX(1.77200) * cb + ONE_HALF;
 227
 228        y  = (*Y++) << SCALEBITS;
 229        r = (y + add_r) >> SCALEBITS;
 230        *p++ = clamp(r);
 231        g = (y + add_g) >> SCALEBITS;
 232        *p++ = clamp(g);
 233        b = (y + add_b) >> SCALEBITS;
 234        *p++ = clamp(b);
 235        a = 255;
 236        *p++ = a;
 237
 238        y  = (Y[8-1]) << SCALEBITS;
 239        r = (y + add_r) >> SCALEBITS;
 240        *p2++ = clamp(r);
 241        g = (y + add_g) >> SCALEBITS;
 242        *p2++ = clamp(g);
 243        b = (y + add_b) >> SCALEBITS;
 244        *p2++ = clamp(b);
 245        a = 255;
 246        *p2++ = a;
 247
 248     }
 249     Y += 8;
 250     p += offset_to_next_row;
 251     p2 += offset_to_next_row;
 252   }
 253
 254 #undef SCALEBITS
 255 #undef ONE_HALF
 256 #undef FIX
 257
 258 }
 259
 260 /**
 261  *  YCrCb -> RGBA32 (2x2)
 262  *  .-------.
 263  *  | 1 | 2 |
 264  *  |---+---|
 265  *  | 3 | 4 |
 266  *  `-------'
 267  */
 268 static void YCrCB_to_RGBA32_2x2(struct jdec_private *priv)
 269 {
 270   const unsigned char *Y, *Cb, *Cr;
 271   unsigned char *p, *p2;
 272   int i,j;
 273   int offset_to_next_row;
 274
 275 #define SCALEBITS       10
 276 #define ONE_HALF        (1UL << (SCALEBITS-1))
 277 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 278
 279   p = priv->plane[0];
 280   p2 = priv->plane[0] + priv->bytes_per_row[0];
 281   Y = priv->Y;
 282   Cb = priv->Cb;
 283   Cr = priv->Cr;
 284   offset_to_next_row = 2*priv->bytes_per_row[0] - 16*4;
 285   for (i=0; i<8; i++) {
 286
 287     for (j=0;j<8;j++) {
 288
 289        int y, cb, cr;
 290        int add_r, add_g, add_b;
 291        int r, g , b, a;
 292
 293        cb = *Cb++ - 128;
 294        cr = *Cr++ - 128;
 295        add_r = FIX(1.40200) * cr + ONE_HALF;
 296        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 297        add_b = FIX(1.77200) * cb + ONE_HALF;
 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        a = 255;
 307        *p++ = a;
 308
 309        y  = (*Y++) << SCALEBITS;
 310        r = (y + add_r) >> SCALEBITS;
 311        *p++ = clamp(r);
 312        g = (y + add_g) >> SCALEBITS;
 313        *p++ = clamp(g);
 314        b = (y + add_b) >> SCALEBITS;
 315        *p++ = clamp(b);
 316        a = 255;
 317        *p++ = a;
 318
 319        y  = (Y[16-2]) << SCALEBITS;
 320        r = (y + add_r) >> SCALEBITS;
 321        *p2++ = clamp(r);
 322        g = (y + add_g) >> SCALEBITS;
 323        *p2++ = clamp(g);
 324        b = (y + add_b) >> SCALEBITS;
 325        *p2++ = clamp(b);
 326        a = 255;
 327        *p2++ = a;
 328
 329        y  = (Y[16-1]) << SCALEBITS;
 330        r = (y + add_r) >> SCALEBITS;
 331        *p2++ = clamp(r);
 332        g = (y + add_g) >> SCALEBITS;
 333        *p2++ = clamp(g);
 334        b = (y + add_b) >> SCALEBITS;
 335        *p2++ = clamp(b);
 336        a = 255;
 337        *p2++ = a;
 338     }
 339     Y  += 16;
 340     p  += offset_to_next_row;
 341     p2 += offset_to_next_row;
 342   }
 343
 344 #undef SCALEBITS
 345 #undef ONE_HALF
 346 #undef FIX
 347
 348 }
 349
 350 static int initialize_rgba32(struct jdec_private *priv,
 351                              unsigned int *bytes_per_blocklines,
 352                              unsigned int *bytes_per_mcu)
 353 {
 354   if (priv->components[0] == NULL)
 355     priv->components[0] = (uint8_t *)malloc(priv->width * priv->height * 4);
 356   if (!priv->bytes_per_row[0])
 357     priv->bytes_per_row[0] = priv->width * 4;
 358
 359   bytes_per_blocklines[0] = priv->bytes_per_row[0];
 360   bytes_per_mcu[0] = 4*8;
 361
 362   return !priv->components[0];
 363 }
 364
 365 static const struct tinyjpeg_colorspace format_rgba32 =
 366   {
 367     {
 368       YCrCB_to_RGBA32_1x1,
 369       YCrCB_to_RGBA32_1x2,
 370       YCrCB_to_RGBA32_2x1,
 371       YCrCB_to_RGBA32_2x2,
 372     },
 373     tinyjpeg_decode_mcu_3comp_table,
 374     initialize_rgba32
 375   };
 376
 377 const tinyjpeg_colorspace_t TINYJPEG_FMT_RGBA32 = &format_rgba32;