video/readers/jpeg.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2008  Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <grub/bitmap.h>
  20 #include <grub/types.h>
  21 #include <grub/normal.h>
  22 #include <grub/dl.h>
  23 #include <grub/mm.h>
  24 #include <grub/misc.h>
  25 #include <grub/bufio.h>
  26
  27 /* Uncomment following define to enable JPEG debug.  */
  28 //#define JPEG_DEBUG
  29
  30 #define JPEG_ESC_CHAR           0xFF
  31
  32 #define JPEG_SAMPLING_1x1       0x11
  33
  34 #define JPEG_MARKER_SOI         0xd8
  35 #define JPEG_MARKER_EOI         0xd9
  36 #define JPEG_MARKER_DHT         0xc4
  37 #define JPEG_MARKER_DQT         0xdb
  38 #define JPEG_MARKER_SOF0        0xc0
  39 #define JPEG_MARKER_SOS         0xda
  40
  41 #define SHIFT_BITS              8
  42 #define CONST(x)                ((int) ((x) * (1L << SHIFT_BITS) + 0.5))
  43
  44 #define JPEG_UNIT_SIZE          8
  45
  46 static const grub_uint8_t jpeg_zigzag_order[64] = {
  47   0, 1, 8, 16, 9, 2, 3, 10,
  48   17, 24, 32, 25, 18, 11, 4, 5,
  49   12, 19, 26, 33, 40, 48, 41, 34,
  50   27, 20, 13, 6, 7, 14, 21, 28,
  51   35, 42, 49, 56, 57, 50, 43, 36,
  52   29, 22, 15, 23, 30, 37, 44, 51,
  53   58, 59, 52, 45, 38, 31, 39, 46,
  54   53, 60, 61, 54, 47, 55, 62, 63
  55 };
  56
  57 typedef int jpeg_data_unit_t[64];
  58
  59 struct grub_jpeg_data
  60 {
  61   grub_file_t file;
  62   struct grub_video_bitmap **bitmap;
  63
  64   int image_width;
  65   int image_height;
  66
  67   grub_uint8_t *huff_value[4];
  68   int huff_offset[4][16];
  69   int huff_maxval[4][16];
  70
  71   grub_uint8_t quan_table[2][64];
  72   int comp_index[3][3];
  73
  74   jpeg_data_unit_t ydu[4];
  75   jpeg_data_unit_t crdu;
  76   jpeg_data_unit_t cbdu;
  77
  78   int vs, hs;
  79
  80   int dc_value[3];
  81
  82   int bit_mask, bit_save;
  83 };
  84
  85 static grub_uint8_t
  86 grub_jpeg_get_byte (struct grub_jpeg_data *data)
  87 {
  88   grub_uint8_t r;
  89
  90   r = 0;
  91   grub_file_read (data->file, &r, 1);
  92
  93   return r;
  94 }
  95
  96 static grub_uint16_t
  97 grub_jpeg_get_word (struct grub_jpeg_data *data)
  98 {
  99   grub_uint16_t r;
 100
 101   r = 0;
 102   grub_file_read (data->file, &r, sizeof (grub_uint16_t));
 103
 104   return grub_be_to_cpu16 (r);
 105 }
 106
 107 static int
 108 grub_jpeg_get_bit (struct grub_jpeg_data *data)
 109 {
 110   int ret;
 111
 112   if (data->bit_mask == 0)
 113     {
 114       data->bit_save = grub_jpeg_get_byte (data);
 115       if (data->bit_save == JPEG_ESC_CHAR)
 116         {
 117           if (grub_jpeg_get_byte (data) != 0)
 118             {
 119               grub_error (GRUB_ERR_BAD_FILE_TYPE,
 120                           "jpeg: invalid 0xFF in data stream");
 121               return 0;
 122             }
 123         }
 124       data->bit_mask = 0x80;
 125     }
 126
 127   ret = ((data->bit_save & data->bit_mask) != 0);
 128   data->bit_mask >>= 1;
 129   return ret;
 130 }
 131
 132 static int
 133 grub_jpeg_get_number (struct grub_jpeg_data *data, int num)
 134 {
 135   int value, i, msb;
 136
 137   if (num == 0)
 138     return 0;
 139
 140   msb = value = grub_jpeg_get_bit (data);
 141   for (i = 1; i < num; i++)
 142     value = (value << 1) + (grub_jpeg_get_bit (data) != 0);
 143   if (!msb)
 144     value += 1 - (1 << num);
 145
 146   return value;
 147 }
 148
 149 static int
 150 grub_jpeg_get_huff_code (struct grub_jpeg_data *data, int id)
 151 {
 152   int code, i;
 153
 154   code = 0;
 155   for (i = 0; i < 16; i++)
 156     {
 157       code <<= 1;
 158       if (grub_jpeg_get_bit (data))
 159         code++;
 160       if (code < data->huff_maxval[id][i])
 161         return data->huff_value[id][code + data->huff_offset[id][i]];
 162     }
 163   grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: huffman decode fails");
 164   return 0;
 165 }
 166
 167 static grub_err_t
 168 grub_jpeg_decode_huff_table (struct grub_jpeg_data *data)
 169 {
 170   int id, ac, i, n, base, ofs;
 171   grub_uint32_t next_marker;
 172   grub_uint8_t count[16];
 173
 174   next_marker = data->file->offset;
 175   next_marker += grub_jpeg_get_word (data);
 176
 177   id = grub_jpeg_get_byte (data);
 178   ac = (id >> 4);
 179   id &= 0xF;
 180   if (id > 1)
 181     return grub_error (GRUB_ERR_BAD_FILE_TYPE,
 182                        "jpeg: too many huffman tables");
 183
 184   if (grub_file_read (data->file, &count, sizeof (count)) !=
 185       sizeof (count))
 186     return grub_errno;
 187
 188   n = 0;
 189   for (i = 0; i < 16; i++)
 190     n += count[i];
 191
 192   id += ac * 2;
 193   data->huff_value[id] = grub_malloc (n);
 194   if (grub_errno)
 195     return grub_errno;
 196
 197   if (grub_file_read (data->file, data->huff_value[id], n) != n)
 198     return grub_errno;
 199
 200   base = 0;
 201   ofs = 0;
 202   for (i = 0; i < 16; i++)
 203     {
 204       base += count[i];
 205       ofs += count[i];
 206
 207       data->huff_maxval[id][i] = base;
 208       data->huff_offset[id][i] = ofs - base;
 209
 210       base <<= 1;
 211     }
 212
 213   if (data->file->offset != next_marker)
 214     grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: extra byte in huffman table");
 215
 216   return grub_errno;
 217 }
 218
 219 static grub_err_t
 220 grub_jpeg_decode_quan_table (struct grub_jpeg_data *data)
 221 {
 222   int id;
 223   grub_uint32_t next_marker;
 224
 225   next_marker = data->file->offset;
 226   next_marker += grub_jpeg_get_word (data);
 227
 228   id = grub_jpeg_get_byte (data);
 229   if (id >= 0x10)               /* Upper 4-bit is precision.  */
 230     return grub_error (GRUB_ERR_BAD_FILE_TYPE,
 231                        "jpeg: only 8-bit precision is supported");
 232
 233   if (id > 1)
 234     return grub_error (GRUB_ERR_BAD_FILE_TYPE,
 235                        "jpeg: too many quantization tables");
 236
 237   if (grub_file_read (data->file, &data->quan_table[id], 64) != 64)
 238     return grub_errno;
 239
 240   if (data->file->offset != next_marker)
 241     grub_error (GRUB_ERR_BAD_FILE_TYPE,
 242                 "jpeg: extra byte in quantization table");
 243
 244   return grub_errno;
 245 }
 246
 247 static grub_err_t
 248 grub_jpeg_decode_sof (struct grub_jpeg_data *data)
 249 {
 250   int i, cc;
 251   grub_uint32_t next_marker;
 252
 253   next_marker = data->file->offset;
 254   next_marker += grub_jpeg_get_word (data);
 255
 256   if (grub_jpeg_get_byte (data) != 8)
 257     return grub_error (GRUB_ERR_BAD_FILE_TYPE,
 258                        "jpeg: only 8-bit precision is supported");
 259
 260   data->image_height = grub_jpeg_get_word (data);
 261   data->image_width = grub_jpeg_get_word (data);
 262
 263   if ((!data->image_height) || (!data->image_width))
 264     return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid image size");
 265
 266   cc = grub_jpeg_get_byte (data);
 267   if (cc != 3)
 268     return grub_error (GRUB_ERR_BAD_FILE_TYPE,
 269                        "jpeg: component count must be 3");
 270
 271   for (i = 0; i < cc; i++)
 272     {
 273       int id, ss;
 274
 275       id = grub_jpeg_get_byte (data) - 1;
 276       if ((id < 0) || (id >= 3))
 277         return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid index");
 278
 279       ss = grub_jpeg_get_byte (data);   /* Sampling factor.  */
 280       if (!id)
 281         {
 282           data->vs = ss & 0xF;  /* Vertical sampling.  */
 283           data->hs = ss >> 4;   /* Horizontal sampling.  */
 284           if ((data->vs > 2) || (data->hs > 2))
 285             return grub_error (GRUB_ERR_BAD_FILE_TYPE,
 286                                "jpeg: sampling method not supported");
 287         }
 288       else if (ss != JPEG_SAMPLING_1x1)
 289         return grub_error (GRUB_ERR_BAD_FILE_TYPE,
 290                            "jpeg: sampling method not supported");
 291       data->comp_index[id][0] = grub_jpeg_get_byte (data);
 292     }
 293
 294   if (data->file->offset != next_marker)
 295     grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: extra byte in sof");
 296
 297   return grub_errno;
 298 }
 299
 300 static void
 301 grub_jpeg_idct_transform (jpeg_data_unit_t du)
 302 {
 303   int *pd;
 304   int i;
 305   int t0, t1, t2, t3, t4, t5, t6, t7;
 306   int v0, v1, v2, v3, v4;
 307
 308   pd = du;
 309   for (i = 0; i < JPEG_UNIT_SIZE; i++, pd++)
 310     {
 311       if ((pd[JPEG_UNIT_SIZE * 1] | pd[JPEG_UNIT_SIZE * 2] |
 312            pd[JPEG_UNIT_SIZE * 3] | pd[JPEG_UNIT_SIZE * 4] |
 313            pd[JPEG_UNIT_SIZE * 5] | pd[JPEG_UNIT_SIZE * 6] |
 314            pd[JPEG_UNIT_SIZE * 7]) == 0)
 315         {
 316           pd[JPEG_UNIT_SIZE * 0] <<= SHIFT_BITS;
 317
 318           pd[JPEG_UNIT_SIZE * 1] = pd[JPEG_UNIT_SIZE * 2]
 319             = pd[JPEG_UNIT_SIZE * 3] = pd[JPEG_UNIT_SIZE * 4]
 320             = pd[JPEG_UNIT_SIZE * 5] = pd[JPEG_UNIT_SIZE * 6]
 321             = pd[JPEG_UNIT_SIZE * 7] = pd[JPEG_UNIT_SIZE * 0];
 322
 323           continue;
 324         }
 325
 326       t0 = pd[JPEG_UNIT_SIZE * 0];
 327       t1 = pd[JPEG_UNIT_SIZE * 2];
 328       t2 = pd[JPEG_UNIT_SIZE * 4];
 329       t3 = pd[JPEG_UNIT_SIZE * 6];
 330
 331       v4 = (t1 + t3) * CONST (0.541196100);
 332
 333       v0 = ((t0 + t2) << SHIFT_BITS);
 334       v1 = ((t0 - t2) << SHIFT_BITS);
 335       v2 = v4 - t3 * CONST (1.847759065);
 336       v3 = v4 + t1 * CONST (0.765366865);
 337
 338       t0 = v0 + v3;
 339       t3 = v0 - v3;
 340       t1 = v1 + v2;
 341       t2 = v1 - v2;
 342
 343       t4 = pd[JPEG_UNIT_SIZE * 7];
 344       t5 = pd[JPEG_UNIT_SIZE * 5];
 345       t6 = pd[JPEG_UNIT_SIZE * 3];
 346       t7 = pd[JPEG_UNIT_SIZE * 1];
 347
 348       v0 = t4 + t7;
 349       v1 = t5 + t6;
 350       v2 = t4 + t6;
 351       v3 = t5 + t7;
 352
 353       v4 = (v2 + v3) * CONST (1.175875602);
 354
 355       v0 *= CONST (0.899976223);
 356       v1 *= CONST (2.562915447);
 357       v2 = v2 * CONST (1.961570560) - v4;
 358       v3 = v3 * CONST (0.390180644) - v4;
 359
 360       t4 = t4 * CONST (0.298631336) - v0 - v2;
 361       t5 = t5 * CONST (2.053119869) - v1 - v3;
 362       t6 = t6 * CONST (3.072711026) - v1 - v2;
 363       t7 = t7 * CONST (1.501321110) - v0 - v3;
 364
 365       pd[JPEG_UNIT_SIZE * 0] = t0 + t7;
 366       pd[JPEG_UNIT_SIZE * 7] = t0 - t7;
 367       pd[JPEG_UNIT_SIZE * 1] = t1 + t6;
 368       pd[JPEG_UNIT_SIZE * 6] = t1 - t6;
 369       pd[JPEG_UNIT_SIZE * 2] = t2 + t5;
 370       pd[JPEG_UNIT_SIZE * 5] = t2 - t5;
 371       pd[JPEG_UNIT_SIZE * 3] = t3 + t4;
 372       pd[JPEG_UNIT_SIZE * 4] = t3 - t4;
 373     }
 374
 375   pd = du;
 376   for (i = 0; i < JPEG_UNIT_SIZE; i++, pd += JPEG_UNIT_SIZE)
 377     {
 378       if ((pd[1] | pd[2] | pd[3] | pd[4] | pd[5] | pd[6] | pd[7]) == 0)
 379         {
 380           pd[0] >>= (SHIFT_BITS + 3);
 381           pd[1] = pd[2] = pd[3] = pd[4] = pd[5] = pd[6] = pd[7] = pd[0];
 382           continue;
 383         }
 384
 385       v4 = (pd[2] + pd[6]) * CONST (0.541196100);
 386
 387       v0 = (pd[0] + pd[4]) << SHIFT_BITS;
 388       v1 = (pd[0] - pd[4]) << SHIFT_BITS;
 389       v2 = v4 - pd[6] * CONST (1.847759065);
 390       v3 = v4 + pd[2] * CONST (0.765366865);
 391
 392       t0 = v0 + v3;
 393       t3 = v0 - v3;
 394       t1 = v1 + v2;
 395       t2 = v1 - v2;
 396
 397       t4 = pd[7];
 398       t5 = pd[5];
 399       t6 = pd[3];
 400       t7 = pd[1];
 401
 402       v0 = t4 + t7;
 403       v1 = t5 + t6;
 404       v2 = t4 + t6;
 405       v3 = t5 + t7;
 406
 407       v4 = (v2 + v3) * CONST (1.175875602);
 408
 409       v0 *= CONST (0.899976223);
 410       v1 *= CONST (2.562915447);
 411       v2 = v2 * CONST (1.961570560) - v4;
 412       v3 = v3 * CONST (0.390180644) - v4;
 413
 414       t4 = t4 * CONST (0.298631336) - v0 - v2;
 415       t5 = t5 * CONST (2.053119869) - v1 - v3;
 416       t6 = t6 * CONST (3.072711026) - v1 - v2;
 417       t7 = t7 * CONST (1.501321110) - v0 - v3;
 418
 419       pd[0] = (t0 + t7) >> (SHIFT_BITS * 2 + 3);
 420       pd[7] = (t0 - t7) >> (SHIFT_BITS * 2 + 3);
 421       pd[1] = (t1 + t6) >> (SHIFT_BITS * 2 + 3);
 422       pd[6] = (t1 - t6) >> (SHIFT_BITS * 2 + 3);
 423       pd[2] = (t2 + t5) >> (SHIFT_BITS * 2 + 3);
 424       pd[5] = (t2 - t5) >> (SHIFT_BITS * 2 + 3);
 425       pd[3] = (t3 + t4) >> (SHIFT_BITS * 2 + 3);
 426       pd[4] = (t3 - t4) >> (SHIFT_BITS * 2 + 3);
 427     }
 428
 429   for (i = 0; i < JPEG_UNIT_SIZE * JPEG_UNIT_SIZE; i++)
 430     {
 431       du[i] += 128;
 432
 433       if (du[i] < 0)
 434         du[i] = 0;
 435       if (du[i] > 255)
 436         du[i] = 255;
 437     }
 438 }
 439
 440 static void
 441 grub_jpeg_decode_du (struct grub_jpeg_data *data, int id, jpeg_data_unit_t du)
 442 {
 443   int pos, h1, h2, qt;
 444
 445   grub_memset (du, 0, sizeof (jpeg_data_unit_t));
 446
 447   qt = data->comp_index[id][0];
 448   h1 = data->comp_index[id][1];
 449   h2 = data->comp_index[id][2];
 450
 451   data->dc_value[id] +=
 452     grub_jpeg_get_number (data, grub_jpeg_get_huff_code (data, h1));
 453
 454   du[0] = data->dc_value[id] * (int) data->quan_table[qt][0];
 455   pos = 1;
 456   while (pos < 64)
 457     {
 458       int num, val;
 459
 460       num = grub_jpeg_get_huff_code (data, h2);
 461       if (!num)
 462         break;
 463
 464       val = grub_jpeg_get_number (data, num & 0xF);
 465       num >>= 4;
 466       pos += num;
 467       du[jpeg_zigzag_order[pos]] = val * (int) data->quan_table[qt][pos];
 468       pos++;
 469     }
 470
 471   grub_jpeg_idct_transform (du);
 472 }
 473
 474 static void
 475 grub_jpeg_ycrcb_to_rgb (int yy, int cr, int cb, grub_uint8_t * rgb)
 476 {
 477   int dd;
 478
 479   cr -= 128;
 480   cb -= 128;
 481
 482   /* Red  */
 483   dd = yy + ((cr * CONST (1.402)) >> SHIFT_BITS);
 484   if (dd < 0)
 485     dd = 0;
 486   if (dd > 255)
 487     dd = 255;
 488   *(rgb++) = dd;
 489
 490   /* Green  */
 491   dd = yy - ((cb * CONST (0.34414) + cr * CONST (0.71414)) >> SHIFT_BITS);
 492   if (dd < 0)
 493     dd = 0;
 494   if (dd > 255)
 495     dd = 255;
 496   *(rgb++) = dd;
 497
 498   /* Blue  */
 499   dd = yy + ((cb * CONST (1.772)) >> SHIFT_BITS);
 500   if (dd < 0)
 501     dd = 0;
 502   if (dd > 255)
 503     dd = 255;
 504   *(rgb++) = dd;
 505 }
 506
 507 static grub_err_t
 508 grub_jpeg_decode_sos (struct grub_jpeg_data *data)
 509 {
 510   int i, cc, r1, c1, nr1, nc1, vb, hb;
 511   grub_uint8_t *ptr1;
 512   grub_uint32_t data_offset;
 513
 514   data_offset = data->file->offset;
 515   data_offset += grub_jpeg_get_word (data);
 516
 517   cc = grub_jpeg_get_byte (data);
 518
 519   if (cc != 3)
 520     return grub_error (GRUB_ERR_BAD_FILE_TYPE,
 521                        "jpeg: component count must be 3");
 522
 523   for (i = 0; i < cc; i++)
 524     {
 525       int id, ht;
 526
 527       id = grub_jpeg_get_byte (data) - 1;
 528       if ((id < 0) || (id >= 3))
 529         return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid index");
 530
 531       ht = grub_jpeg_get_byte (data);
 532       data->comp_index[id][1] = (ht >> 4);
 533       data->comp_index[id][2] = (ht & 0xF) + 2;
 534     }
 535
 536   grub_jpeg_get_byte (data);    /* Skip 3 unused bytes.  */
 537   grub_jpeg_get_word (data);
 538
 539   if (data->file->offset != data_offset)
 540     return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: extra byte in sos");
 541
 542   if (grub_video_bitmap_create (data->bitmap, data->image_width,
 543                                 data->image_height,
 544                                 GRUB_VIDEO_BLIT_FORMAT_RGB_888))
 545     return grub_errno;
 546
 547   data->bit_mask = 0x0;
 548
 549   vb = data->vs * 8;
 550   hb = data->hs * 8;
 551   nr1 = (data->image_height + vb - 1) / vb;
 552   nc1 = (data->image_width + hb - 1) / hb;
 553
 554   ptr1 = (*data->bitmap)->data;
 555   for (r1 = 0; r1 < nr1;
 556        r1++, ptr1 += (vb * data->image_width - hb * nc1) * 3)
 557     for (c1 = 0; c1 < nc1; c1++, ptr1 += hb * 3)
 558       {
 559         int r2, c2, nr2, nc2;
 560         grub_uint8_t *ptr2;
 561
 562         for (r2 = 0; r2 < data->vs; r2++)
 563           for (c2 = 0; c2 < data->hs; c2++)
 564             grub_jpeg_decode_du (data, 0, data->ydu[r2 * 2 + c2]);
 565
 566         grub_jpeg_decode_du (data, 1, data->cbdu);
 567         grub_jpeg_decode_du (data, 2, data->crdu);
 568
 569         if (grub_errno)
 570           return grub_errno;
 571
 572         nr2 = (r1 == nr1 - 1) ? (data->image_height - r1 * vb) : vb;
 573         nc2 = (c1 == nc1 - 1) ? (data->image_width - c1 * hb) : hb;
 574
 575         ptr2 = ptr1;
 576         for (r2 = 0; r2 < nr2; r2++, ptr2 += (data->image_width - nc2) * 3)
 577           for (c2 = 0; c2 < nc2; c2++, ptr2 += 3)
 578             {
 579               int i0, yy, cr, cb;
 580
 581               i0 = (r2 / data->vs) * 8 + (c2 / data->hs);
 582               cr = data->crdu[i0];
 583               cb = data->cbdu[i0];
 584               yy =
 585                 data->ydu[(r2 / 8) * 2 + (c2 / 8)][(r2 % 8) * 8 + (c2 % 8)];
 586
 587               grub_jpeg_ycrcb_to_rgb (yy, cr, cb, ptr2);
 588             }
 589       }
 590
 591   return grub_errno;
 592 }
 593
 594 static grub_uint8_t
 595 grub_jpeg_get_marker (struct grub_jpeg_data *data)
 596 {
 597   grub_uint8_t r;
 598
 599   r = grub_jpeg_get_byte (data);
 600
 601   if (r != JPEG_ESC_CHAR)
 602     {
 603       grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid maker");
 604       return 0;
 605     }
 606
 607   return grub_jpeg_get_byte (data);
 608 }
 609
 610 static grub_err_t
 611 grub_jpeg_decode_jpeg (struct grub_jpeg_data *data)
 612 {
 613   if (grub_jpeg_get_marker (data) != JPEG_MARKER_SOI)   /* Start Of Image.  */
 614     return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid jpeg file");
 615
 616   while (grub_errno == 0)
 617     {
 618       grub_uint8_t marker;
 619
 620       marker = grub_jpeg_get_marker (data);
 621       if (grub_errno)
 622         break;
 623
 624 #ifdef JPEG_DEBUG
 625       grub_printf ("jpeg marker: %x\n", marker);
 626 #endif
 627
 628       switch (marker)
 629         {
 630         case JPEG_MARKER_DHT:   /* Define Huffman Table.  */
 631           grub_jpeg_decode_huff_table (data);
 632           break;
 633         case JPEG_MARKER_DQT:   /* Define Quantization Table.  */
 634           grub_jpeg_decode_quan_table (data);
 635           break;
 636         case JPEG_MARKER_SOF0:  /* Start Of Frame 0.  */
 637           grub_jpeg_decode_sof (data);
 638           break;
 639         case JPEG_MARKER_SOS:   /* Start Of Scan.  */
 640           grub_jpeg_decode_sos (data);
 641           break;
 642         case JPEG_MARKER_EOI:   /* End Of Image.  */
 643           return grub_errno;
 644         default:                /* Skip unrecognized marker.  */
 645           {
 646             grub_uint16_t sz;
 647
 648             sz = grub_jpeg_get_word (data);
 649             if (grub_errno)
 650               return (grub_errno);
 651             grub_file_seek (data->file, data->file->offset + sz - 2);
 652           }
 653         }
 654     }
 655
 656   return grub_errno;
 657 }
 658
 659 static grub_err_t
 660 grub_video_reader_jpeg (struct grub_video_bitmap **bitmap,
 661                         const char *filename)
 662 {
 663   grub_file_t file;
 664   struct grub_jpeg_data *data;
 665
 666   file = grub_buffile_open (filename, 0);
 667   if (!file)
 668     return grub_errno;
 669
 670   data = grub_zalloc (sizeof (*data));
 671   if (data != NULL)
 672     {
 673       int i;
 674
 675       data->file = file;
 676       data->bitmap = bitmap;
 677       grub_jpeg_decode_jpeg (data);
 678
 679       for (i = 0; i < 4; i++)
 680         if (data->huff_value[i])
 681           grub_free (data->huff_value[i]);
 682
 683       grub_free (data);
 684     }
 685
 686   if (grub_errno != GRUB_ERR_NONE)
 687     {
 688       grub_video_bitmap_destroy (*bitmap);
 689       *bitmap = 0;
 690     }
 691
 692   grub_file_close (file);
 693   return grub_errno;
 694 }
 695
 696 #if defined(JPEG_DEBUG)
 697 static grub_err_t
 698 grub_cmd_jpegtest (struct grub_arg_list *state __attribute__ ((unused)),
 699                    int argc, char **args)
 700 {
 701   struct grub_video_bitmap *bitmap = 0;
 702
 703   if (argc != 1)
 704     return grub_error (GRUB_ERR_BAD_ARGUMENT, "file name required");
 705
 706   grub_video_reader_jpeg (&bitmap, args[0]);
 707   if (grub_errno != GRUB_ERR_NONE)
 708     return grub_errno;
 709
 710   grub_video_bitmap_destroy (bitmap);
 711
 712   return GRUB_ERR_NONE;
 713 }
 714 #endif
 715
 716 static struct grub_video_bitmap_reader jpg_reader = {
 717   .extension = ".jpg",
 718   .reader = grub_video_reader_jpeg,
 719   .next = 0
 720 };
 721
 722 static struct grub_video_bitmap_reader jpeg_reader = {
 723   .extension = ".jpeg",
 724   .reader = grub_video_reader_jpeg,
 725   .next = 0
 726 };
 727
 728 GRUB_MOD_INIT (video_reader_jpeg)
 729 {
 730   grub_video_bitmap_reader_register (&jpg_reader);
 731   grub_video_bitmap_reader_register (&jpeg_reader);
 732 #if defined(JPEG_DEBUG)
 733   grub_register_command ("jpegtest", grub_cmd_jpegtest,
 734                          GRUB_COMMAND_FLAG_BOTH, "jpegtest FILE",
 735                          "Tests loading of JPEG bitmap.", 0);
 736 #endif
 737 }
 738
 739 GRUB_MOD_FINI (video_reader_jpeg)
 740 {
 741 #if defined(JPEG_DEBUG)
 742   grub_unregister_command ("jpegtest");
 743 #endif
 744   grub_video_bitmap_reader_unregister (&jpeg_reader);
 745   grub_video_bitmap_reader_unregister (&jpg_reader);
 746 }