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, int sx, int sy)
  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 = sy; i > 0; i--) {
  89     for (j = sx; j > 0; j++) {
  90        int y, cb, cr;
  91        int add_r, add_g, add_b;
  92        int r, g , b;
  93
  94        y  = Y[0] << SCALEBITS;
  95        cb = *Cb++ - 128;
  96        cr = *Cr++ - 128;
  97        add_r = FIX(1.40200) * cr + ONE_HALF;
  98        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
  99        add_b = FIX(1.77200) * cb + ONE_HALF;
 100
 101        r = (y + add_r) >> SCALEBITS;
 102        *p++ = clamp(r);
 103        g = (y + add_g) >> SCALEBITS;
 104        *p++ = clamp(g);
 105        b = (y + add_b) >> SCALEBITS;
 106        *p++ = clamp(b);
 107
 108        Y++;
 109     }
 110
 111     p += offset_to_next_row;
 112   }
 113
 114 #undef SCALEBITS
 115 #undef ONE_HALF
 116 #undef FIX
 117
 118 }
 119
 120 /**
 121  *  YCrCb -> RGB24 (2x1)
 122  *  .-------.
 123  *  | 1 | 2 |
 124  *  `-------'
 125  */
 126 static void YCrCB_to_RGB24_2x1(struct jdec_private *priv, int sx, int sy)
 127 {
 128   const unsigned char *Y, *Cb, *Cr;
 129   unsigned char *p;
 130   int i,j;
 131   int offset_to_next_row;
 132
 133 #define SCALEBITS       10
 134 #define ONE_HALF        (1UL << (SCALEBITS-1))
 135 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 136
 137   p = priv->plane[0];
 138   Y = priv->Y;
 139   Cb = priv->Cb;
 140   Cr = priv->Cr;
 141   offset_to_next_row = priv->bytes_per_row[0] - 16*3;
 142   for (i = sy; i > 0; i--) {
 143
 144     for (j = sx; j > 0; j -= 2) {
 145
 146        int y, cb, cr;
 147        int add_r, add_g, add_b;
 148        int r, g , b;
 149
 150        y  = Y[0] << SCALEBITS;
 151        cb = *Cb++ - 128;
 152        cr = *Cr++ - 128;
 153        add_r = FIX(1.40200) * cr + ONE_HALF;
 154        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 155        add_b = FIX(1.77200) * cb + ONE_HALF;
 156
 157        r = (y + add_r) >> SCALEBITS;
 158        *p++ = clamp(r);
 159        g = (y + add_g) >> SCALEBITS;
 160        *p++ = clamp(g);
 161        b = (y + add_b) >> SCALEBITS;
 162        *p++ = clamp(b);
 163
 164        if (j > 1) {
 165            y  = Y[1] << 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        Y += 2;
 175     }
 176
 177     p += offset_to_next_row;
 178   }
 179
 180 #undef SCALEBITS
 181 #undef ONE_HALF
 182 #undef FIX
 183
 184 }
 185
 186
 187 /**
 188  *  YCrCb -> RGB24 (1x2)
 189  *  .---.
 190  *  | 1 |
 191  *  |---|
 192  *  | 2 |
 193  *  `---'
 194  */
 195 static void YCrCB_to_RGB24_1x2(struct jdec_private *priv, int sx, int sy)
 196 {
 197   const unsigned char *Y, *Cb, *Cr;
 198   unsigned char *p, *p2;
 199   int i,j;
 200   int offset_to_next_row;
 201
 202 #define SCALEBITS       10
 203 #define ONE_HALF        (1UL << (SCALEBITS-1))
 204 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 205
 206   p = priv->plane[0];
 207   p2 = priv->plane[0] + priv->bytes_per_row[0];
 208   Y = priv->Y;
 209   Cb = priv->Cb;
 210   Cr = priv->Cr;
 211   offset_to_next_row = 2*priv->bytes_per_row[0] - 8*3;
 212   for (i = sy; i > 0; i -= 2) {
 213     for (j = sx; j > 0; j--) {
 214
 215        int y, cb, cr;
 216        int add_r, add_g, add_b;
 217        int r, g , b;
 218
 219        cb = *Cb++ - 128;
 220        cr = *Cr++ - 128;
 221        add_r = FIX(1.40200) * cr + ONE_HALF;
 222        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 223        add_b = FIX(1.77200) * cb + ONE_HALF;
 224
 225        y  = Y[0] << SCALEBITS;
 226        r = (y + add_r) >> SCALEBITS;
 227        *p++ = clamp(r);
 228        g = (y + add_g) >> SCALEBITS;
 229        *p++ = clamp(g);
 230        b = (y + add_b) >> SCALEBITS;
 231        *p++ = clamp(b);
 232
 233        if (i > 1) {
 234            y  = Y[8] << SCALEBITS;
 235            r = (y + add_r) >> SCALEBITS;
 236            *p2++ = clamp(r);
 237            g = (y + add_g) >> SCALEBITS;
 238            *p2++ = clamp(g);
 239            b = (y + add_b) >> SCALEBITS;
 240            *p2++ = clamp(b);
 241        }
 242
 243        Y++;
 244     }
 245     Y += 8;
 246     p += offset_to_next_row;
 247     p2 += offset_to_next_row;
 248   }
 249
 250 #undef SCALEBITS
 251 #undef ONE_HALF
 252 #undef FIX
 253
 254 }
 255
 256 /**
 257  *  YCrCb -> RGB24 (2x2)
 258  *  .-------.
 259  *  | 1 | 2 |
 260  *  |---+---|
 261  *  | 3 | 4 |
 262  *  `-------'
 263  */
 264 static void YCrCB_to_RGB24_2x2(struct jdec_private *priv, int sx, int sy)
 265 {
 266   const unsigned char *Y, *Cb, *Cr;
 267   unsigned char *p, *p2;
 268   int i,j;
 269   int offset_to_next_row;
 270
 271 #define SCALEBITS       10
 272 #define ONE_HALF        (1UL << (SCALEBITS-1))
 273 #define FIX(x)          ((int)((x) * (1UL<<SCALEBITS) + 0.5))
 274
 275   p = priv->plane[0];
 276   p2 = priv->plane[0] + priv->bytes_per_row[0];
 277   Y = priv->Y;
 278   Cb = priv->Cb;
 279   Cr = priv->Cr;
 280   offset_to_next_row = 2*priv->bytes_per_row[0] - 16*3;
 281   for (i = sy; i > 0; i -= 2) {
 282     for (j = sx; j > 0; j -= 2) {
 283
 284        int y, cb, cr;
 285        int add_r, add_g, add_b;
 286        int r, g , b;
 287
 288        cb = *Cb++ - 128;
 289        cr = *Cr++ - 128;
 290        add_r = FIX(1.40200) * cr + ONE_HALF;
 291        add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
 292        add_b = FIX(1.77200) * cb + ONE_HALF;
 293
 294        y  = Y[0] << SCALEBITS;
 295        r = (y + add_r) >> SCALEBITS;
 296        *p++ = clamp(r);
 297        g = (y + add_g) >> SCALEBITS;
 298        *p++ = clamp(g);
 299        b = (y + add_b) >> SCALEBITS;
 300        *p++ = clamp(b);
 301
 302        if (j > 1) {
 303            y  = Y[1] << SCALEBITS;
 304            r = (y + add_r) >> SCALEBITS;
 305            *p++ = clamp(r);
 306            g = (y + add_g) >> SCALEBITS;
 307            *p++ = clamp(g);
 308            b = (y + add_b) >> SCALEBITS;
 309            *p++ = clamp(b);
 310        }
 311
 312        if (i > 1) {
 313            y  = Y[16+0] << SCALEBITS;
 314            r = (y + add_r) >> SCALEBITS;
 315            *p2++ = clamp(r);
 316            g = (y + add_g) >> SCALEBITS;
 317            *p2++ = clamp(g);
 318            b = (y + add_b) >> SCALEBITS;
 319            *p2++ = clamp(b);
 320
 321            if (j > 1) {
 322                y  = Y[16+1] << SCALEBITS;
 323                r = (y + add_r) >> SCALEBITS;
 324                *p2++ = clamp(r);
 325                g = (y + add_g) >> SCALEBITS;
 326                *p2++ = clamp(g);
 327                b = (y + add_b) >> SCALEBITS;
 328                *p2++ = clamp(b);
 329            }
 330        }
 331
 332        Y += 2;
 333     }
 334     Y  += 16;
 335     p  += offset_to_next_row;
 336     p2 += offset_to_next_row;
 337   }
 338
 339 #undef SCALEBITS
 340 #undef ONE_HALF
 341 #undef FIX
 342
 343 }
 344
 345 static int initialize_rgb24(struct jdec_private *priv,
 346                             unsigned int *bytes_per_blocklines,
 347                             unsigned int *bytes_per_mcu)
 348 {
 349   if (!priv->bytes_per_row[0])
 350     priv->bytes_per_row[0] = priv->width * 3;
 351   if (priv->components[0] == NULL)
 352     priv->components[0] = malloc(priv->height * priv->bytes_per_row[0]);
 353
 354   bytes_per_blocklines[0] = priv->bytes_per_row[0] << 3;
 355   bytes_per_mcu[0] = 3*8;
 356
 357   return !priv->components[0];
 358 }
 359
 360 static const struct tinyjpeg_colorspace format_rgb24 =
 361   {
 362     {
 363       YCrCB_to_RGB24_1x1,
 364       YCrCB_to_RGB24_1x2,
 365       YCrCB_to_RGB24_2x1,
 366       YCrCB_to_RGB24_2x2,
 367     },
 368     tinyjpeg_decode_mcu_3comp_table,
 369     initialize_rgb24
 370   };
 371
 372 const tinyjpeg_colorspace_t TINYJPEG_FMT_RGB24 = &format_rgb24;