| 1 | |
| 2 | /* pngrutil.c - utilities to read a PNG file |
| 3 | * |
| 4 | * libpng 1.0.3 - January 14, 1999 |
| 5 | * For conditions of distribution and use, see copyright notice in png.h |
| 6 | * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
| 7 | * Copyright (c) 1996, 1997 Andreas Dilger |
| 8 | * Copyright (c) 1998, 1999 Glenn Randers-Pehrson |
| 9 | * |
| 10 | * This file contains routines that are only called from within |
| 11 | * libpng itself during the course of reading an image. |
| 12 | */ |
| 13 | |
| 14 | #define PNG_INTERNAL |
| 15 | #include "png.h" |
| 16 | |
| 17 | #ifndef PNG_READ_BIG_ENDIAN_SUPPORTED |
| 18 | /* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ |
| 19 | png_uint_32 |
| 20 | png_get_uint_32(png_bytep buf) |
| 21 | { |
| 22 | png_uint_32 i = ((png_uint_32)(*buf) << 24) + |
| 23 | ((png_uint_32)(*(buf + 1)) << 16) + |
| 24 | ((png_uint_32)(*(buf + 2)) << 8) + |
| 25 | (png_uint_32)(*(buf + 3)); |
| 26 | |
| 27 | return (i); |
| 28 | } |
| 29 | |
| 30 | #if defined(PNG_READ_pCAL_SUPPORTED) |
| 31 | /* Grab a signed 32-bit integer from a buffer in big-endian format. The |
| 32 | * data is stored in the PNG file in two's complement format, and it is |
| 33 | * assumed that the machine format for signed integers is the same. */ |
| 34 | png_int_32 |
| 35 | png_get_int_32(png_bytep buf) |
| 36 | { |
| 37 | png_int_32 i = ((png_int_32)(*buf) << 24) + |
| 38 | ((png_int_32)(*(buf + 1)) << 16) + |
| 39 | ((png_int_32)(*(buf + 2)) << 8) + |
| 40 | (png_int_32)(*(buf + 3)); |
| 41 | |
| 42 | return (i); |
| 43 | } |
| 44 | #endif /* PNG_READ_pCAL_SUPPORTED */ |
| 45 | |
| 46 | /* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ |
| 47 | png_uint_16 |
| 48 | png_get_uint_16(png_bytep buf) |
| 49 | { |
| 50 | png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) + |
| 51 | (png_uint_16)(*(buf + 1))); |
| 52 | |
| 53 | return (i); |
| 54 | } |
| 55 | #endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */ |
| 56 | |
| 57 | /* Read data, and (optionally) run it through the CRC. */ |
| 58 | void |
| 59 | png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length) |
| 60 | { |
| 61 | png_read_data(png_ptr, buf, length); |
| 62 | png_calculate_crc(png_ptr, buf, length); |
| 63 | } |
| 64 | |
| 65 | /* Optionally skip data and then check the CRC. Depending on whether we |
| 66 | are reading a ancillary or critical chunk, and how the program has set |
| 67 | things up, we may calculate the CRC on the data and print a message. |
| 68 | Returns '1' if there was a CRC error, '0' otherwise. */ |
| 69 | int |
| 70 | png_crc_finish(png_structp png_ptr, png_uint_32 skip) |
| 71 | { |
| 72 | png_size_t i; |
| 73 | png_size_t istop = png_ptr->zbuf_size; |
| 74 | |
| 75 | for (i = (png_size_t)skip; i > istop; i -= istop) |
| 76 | { |
| 77 | png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); |
| 78 | } |
| 79 | if (i) |
| 80 | { |
| 81 | png_crc_read(png_ptr, png_ptr->zbuf, i); |
| 82 | } |
| 83 | |
| 84 | if (png_crc_error(png_ptr)) |
| 85 | { |
| 86 | if ((png_ptr->chunk_name[0] & 0x20 && /* Ancillary */ |
| 87 | !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) || |
| 88 | (!(png_ptr->chunk_name[0] & 0x20) && /* Critical */ |
| 89 | png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)) |
| 90 | { |
| 91 | png_chunk_warning(png_ptr, "CRC error"); |
| 92 | } |
| 93 | else |
| 94 | { |
| 95 | png_chunk_error(png_ptr, "CRC error"); |
| 96 | } |
| 97 | return (1); |
| 98 | } |
| 99 | |
| 100 | return (0); |
| 101 | } |
| 102 | |
| 103 | /* Compare the CRC stored in the PNG file with that calculated by libpng from |
| 104 | the data it has read thus far. */ |
| 105 | int |
| 106 | png_crc_error(png_structp png_ptr) |
| 107 | { |
| 108 | png_byte crc_bytes[4]; |
| 109 | png_uint_32 crc; |
| 110 | int need_crc = 1; |
| 111 | |
| 112 | if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ |
| 113 | { |
| 114 | if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == |
| 115 | (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) |
| 116 | need_crc = 0; |
| 117 | } |
| 118 | else /* critical */ |
| 119 | { |
| 120 | if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) |
| 121 | need_crc = 0; |
| 122 | } |
| 123 | |
| 124 | png_read_data(png_ptr, crc_bytes, 4); |
| 125 | |
| 126 | if (need_crc) |
| 127 | { |
| 128 | crc = png_get_uint_32(crc_bytes); |
| 129 | return ((int)(crc != png_ptr->crc)); |
| 130 | } |
| 131 | else |
| 132 | return (0); |
| 133 | } |
| 134 | |
| 135 | |
| 136 | /* read and check the IDHR chunk */ |
| 137 | void |
| 138 | png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 139 | { |
| 140 | png_byte buf[13]; |
| 141 | png_uint_32 width, height; |
| 142 | int bit_depth, color_type, compression_type, filter_type; |
| 143 | int interlace_type; |
| 144 | |
| 145 | png_debug(1, "in png_handle_IHDR\n"); |
| 146 | |
| 147 | if (png_ptr->mode != PNG_BEFORE_IHDR) |
| 148 | png_error(png_ptr, "Out of place IHDR"); |
| 149 | |
| 150 | /* check the length */ |
| 151 | if (length != 13) |
| 152 | png_error(png_ptr, "Invalid IHDR chunk"); |
| 153 | |
| 154 | png_ptr->mode |= PNG_HAVE_IHDR; |
| 155 | |
| 156 | png_crc_read(png_ptr, buf, 13); |
| 157 | png_crc_finish(png_ptr, 0); |
| 158 | |
| 159 | width = png_get_uint_32(buf); |
| 160 | height = png_get_uint_32(buf + 4); |
| 161 | bit_depth = buf[8]; |
| 162 | color_type = buf[9]; |
| 163 | compression_type = buf[10]; |
| 164 | filter_type = buf[11]; |
| 165 | interlace_type = buf[12]; |
| 166 | |
| 167 | /* check for width and height valid values */ |
| 168 | if (width == 0 || width > (png_uint_32)2147483647L || height == 0 || |
| 169 | height > (png_uint_32)2147483647L) |
| 170 | png_error(png_ptr, "Invalid image size in IHDR"); |
| 171 | |
| 172 | /* check other values */ |
| 173 | if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 && |
| 174 | bit_depth != 8 && bit_depth != 16) |
| 175 | png_error(png_ptr, "Invalid bit depth in IHDR"); |
| 176 | |
| 177 | if (color_type < 0 || color_type == 1 || |
| 178 | color_type == 5 || color_type > 6) |
| 179 | png_error(png_ptr, "Invalid color type in IHDR"); |
| 180 | |
| 181 | if ((color_type == PNG_COLOR_TYPE_PALETTE && bit_depth) > 8 || |
| 182 | ((color_type == PNG_COLOR_TYPE_RGB || |
| 183 | color_type == PNG_COLOR_TYPE_GRAY_ALPHA || |
| 184 | color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8)) |
| 185 | png_error(png_ptr, "Invalid color type/bit depth combination in IHDR"); |
| 186 | |
| 187 | if (interlace_type >= PNG_INTERLACE_LAST) |
| 188 | png_error(png_ptr, "Unknown interlace method in IHDR"); |
| 189 | |
| 190 | if (compression_type != PNG_COMPRESSION_TYPE_BASE) |
| 191 | png_error(png_ptr, "Unknown compression method in IHDR"); |
| 192 | |
| 193 | if (filter_type != PNG_FILTER_TYPE_BASE) |
| 194 | png_error(png_ptr, "Unknown filter method in IHDR"); |
| 195 | |
| 196 | /* set internal variables */ |
| 197 | png_ptr->width = width; |
| 198 | png_ptr->height = height; |
| 199 | png_ptr->bit_depth = (png_byte)bit_depth; |
| 200 | png_ptr->interlaced = (png_byte)interlace_type; |
| 201 | png_ptr->color_type = (png_byte)color_type; |
| 202 | |
| 203 | /* find number of channels */ |
| 204 | switch (png_ptr->color_type) |
| 205 | { |
| 206 | case PNG_COLOR_TYPE_GRAY: |
| 207 | case PNG_COLOR_TYPE_PALETTE: |
| 208 | png_ptr->channels = 1; |
| 209 | break; |
| 210 | case PNG_COLOR_TYPE_RGB: |
| 211 | png_ptr->channels = 3; |
| 212 | break; |
| 213 | case PNG_COLOR_TYPE_GRAY_ALPHA: |
| 214 | png_ptr->channels = 2; |
| 215 | break; |
| 216 | case PNG_COLOR_TYPE_RGB_ALPHA: |
| 217 | png_ptr->channels = 4; |
| 218 | break; |
| 219 | } |
| 220 | |
| 221 | /* set up other useful info */ |
| 222 | png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * |
| 223 | png_ptr->channels); |
| 224 | png_ptr->rowbytes = ((png_ptr->width * |
| 225 | (png_uint_32)png_ptr->pixel_depth + 7) >> 3); |
| 226 | png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth); |
| 227 | png_debug1(3,"channels = %d\n", png_ptr->channels); |
| 228 | png_debug1(3,"rowbytes = %d\n", png_ptr->rowbytes); |
| 229 | png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, |
| 230 | color_type, interlace_type, compression_type, filter_type); |
| 231 | } |
| 232 | |
| 233 | /* read and check the palette */ |
| 234 | void |
| 235 | png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 236 | { |
| 237 | png_colorp palette; |
| 238 | int num, i; |
| 239 | |
| 240 | png_debug(1, "in png_handle_PLTE\n"); |
| 241 | |
| 242 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 243 | png_error(png_ptr, "Missing IHDR before PLTE"); |
| 244 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 245 | { |
| 246 | png_warning(png_ptr, "Invalid PLTE after IDAT"); |
| 247 | png_crc_finish(png_ptr, length); |
| 248 | return; |
| 249 | } |
| 250 | else if (png_ptr->mode & PNG_HAVE_PLTE) |
| 251 | png_error(png_ptr, "Duplicate PLTE chunk"); |
| 252 | |
| 253 | png_ptr->mode |= PNG_HAVE_PLTE; |
| 254 | |
| 255 | #if !defined(PNG_READ_OPT_PLTE_SUPPORTED) |
| 256 | if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) |
| 257 | { |
| 258 | png_crc_finish(png_ptr, length); |
| 259 | return; |
| 260 | } |
| 261 | #endif |
| 262 | |
| 263 | if (length % 3) |
| 264 | { |
| 265 | if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) |
| 266 | { |
| 267 | png_warning(png_ptr, "Invalid palette chunk"); |
| 268 | png_crc_finish(png_ptr, length); |
| 269 | return; |
| 270 | } |
| 271 | else |
| 272 | { |
| 273 | png_error(png_ptr, "Invalid palette chunk"); |
| 274 | } |
| 275 | } |
| 276 | |
| 277 | num = (int)length / 3; |
| 278 | palette = (png_colorp)png_zalloc(png_ptr, (uInt)num, sizeof (png_color)); |
| 279 | png_ptr->flags |= PNG_FLAG_FREE_PALETTE; |
| 280 | for (i = 0; i < num; i++) |
| 281 | { |
| 282 | png_byte buf[3]; |
| 283 | |
| 284 | png_crc_read(png_ptr, buf, 3); |
| 285 | /* don't depend upon png_color being any order */ |
| 286 | palette[i].red = buf[0]; |
| 287 | palette[i].green = buf[1]; |
| 288 | palette[i].blue = buf[2]; |
| 289 | } |
| 290 | |
| 291 | /* If we actually NEED the PLTE chunk (ie for a paletted image), we do |
| 292 | whatever the normal CRC configuration tells us. However, if we |
| 293 | have an RGB image, the PLTE can be considered ancillary, so |
| 294 | we will act as though it is. */ |
| 295 | #if !defined(PNG_READ_OPT_PLTE_SUPPORTED) |
| 296 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 297 | #endif |
| 298 | { |
| 299 | png_crc_finish(png_ptr, 0); |
| 300 | } |
| 301 | #if !defined(PNG_READ_OPT_PLTE_SUPPORTED) |
| 302 | else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */ |
| 303 | { |
| 304 | /* If we don't want to use the data from an ancillary chunk, |
| 305 | we have two options: an error abort, or a warning and we |
| 306 | ignore the data in this chunk (which should be OK, since |
| 307 | it's considered ancillary for a RGB or RGBA image). */ |
| 308 | if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE)) |
| 309 | { |
| 310 | if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) |
| 311 | { |
| 312 | png_chunk_error(png_ptr, "CRC error"); |
| 313 | } |
| 314 | else |
| 315 | { |
| 316 | png_chunk_warning(png_ptr, "CRC error"); |
| 317 | png_ptr->flags &= ~PNG_FLAG_FREE_PALETTE; |
| 318 | png_zfree(png_ptr, palette); |
| 319 | return; |
| 320 | } |
| 321 | } |
| 322 | /* Otherwise, we (optionally) emit a warning and use the chunk. */ |
| 323 | else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) |
| 324 | { |
| 325 | png_chunk_warning(png_ptr, "CRC error"); |
| 326 | } |
| 327 | } |
| 328 | #endif |
| 329 | png_ptr->palette = palette; |
| 330 | png_ptr->num_palette = (png_uint_16)num; |
| 331 | png_set_PLTE(png_ptr, info_ptr, palette, num); |
| 332 | |
| 333 | #if defined (PNG_READ_tRNS_SUPPORTED) |
| 334 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 335 | { |
| 336 | if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS) |
| 337 | { |
| 338 | if (png_ptr->num_trans > png_ptr->num_palette) |
| 339 | { |
| 340 | png_warning(png_ptr, "Truncating incorrect tRNS chunk length"); |
| 341 | png_ptr->num_trans = png_ptr->num_palette; |
| 342 | } |
| 343 | } |
| 344 | } |
| 345 | #endif |
| 346 | |
| 347 | } |
| 348 | |
| 349 | void |
| 350 | png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 351 | { |
| 352 | png_debug(1, "in png_handle_IEND\n"); |
| 353 | |
| 354 | if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT)) |
| 355 | { |
| 356 | png_error(png_ptr, "No image in file"); |
| 357 | |
| 358 | /* to quiet compiler warnings about unused info_ptr */ |
| 359 | if (info_ptr == NULL) |
| 360 | return; |
| 361 | } |
| 362 | |
| 363 | png_ptr->mode |= PNG_AFTER_IDAT | PNG_HAVE_IEND; |
| 364 | |
| 365 | if (length != 0) |
| 366 | { |
| 367 | png_warning(png_ptr, "Incorrect IEND chunk length"); |
| 368 | } |
| 369 | png_crc_finish(png_ptr, length); |
| 370 | } |
| 371 | |
| 372 | #if defined(PNG_READ_gAMA_SUPPORTED) |
| 373 | void |
| 374 | png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 375 | { |
| 376 | png_uint_32 igamma; |
| 377 | float file_gamma; |
| 378 | png_byte buf[4]; |
| 379 | |
| 380 | png_debug(1, "in png_handle_gAMA\n"); |
| 381 | |
| 382 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 383 | png_error(png_ptr, "Missing IHDR before gAMA"); |
| 384 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 385 | { |
| 386 | png_warning(png_ptr, "Invalid gAMA after IDAT"); |
| 387 | png_crc_finish(png_ptr, length); |
| 388 | return; |
| 389 | } |
| 390 | else if (png_ptr->mode & PNG_HAVE_PLTE) |
| 391 | /* Should be an error, but we can cope with it */ |
| 392 | png_warning(png_ptr, "Out of place gAMA chunk"); |
| 393 | |
| 394 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_gAMA |
| 395 | #if defined(PNG_READ_sRGB_SUPPORTED) |
| 396 | && !(info_ptr->valid & PNG_INFO_sRGB) |
| 397 | #endif |
| 398 | ) |
| 399 | { |
| 400 | png_warning(png_ptr, "Duplicate gAMA chunk"); |
| 401 | png_crc_finish(png_ptr, length); |
| 402 | return; |
| 403 | } |
| 404 | |
| 405 | if (length != 4) |
| 406 | { |
| 407 | png_warning(png_ptr, "Incorrect gAMA chunk length"); |
| 408 | png_crc_finish(png_ptr, length); |
| 409 | return; |
| 410 | } |
| 411 | |
| 412 | png_crc_read(png_ptr, buf, 4); |
| 413 | if (png_crc_finish(png_ptr, 0)) |
| 414 | return; |
| 415 | |
| 416 | igamma = png_get_uint_32(buf); |
| 417 | /* check for zero gamma */ |
| 418 | if (igamma == 0) |
| 419 | return; |
| 420 | |
| 421 | #if defined(PNG_READ_sRGB_SUPPORTED) |
| 422 | if (info_ptr->valid & PNG_INFO_sRGB) |
| 423 | if(igamma != (png_uint_32)45000L) |
| 424 | { |
| 425 | png_warning(png_ptr, |
| 426 | "Ignoring incorrect gAMA value when sRGB is also present"); |
| 427 | #ifndef PNG_NO_CONSOLE_IO |
| 428 | fprintf(stderr, "igamma = %lu\n", igamma); |
| 429 | #endif |
| 430 | return; |
| 431 | } |
| 432 | #endif /* PNG_READ_sRGB_SUPPORTED */ |
| 433 | |
| 434 | file_gamma = (float)igamma / (float)100000.0; |
| 435 | #ifdef PNG_READ_GAMMA_SUPPORTED |
| 436 | png_ptr->gamma = file_gamma; |
| 437 | #endif |
| 438 | png_set_gAMA(png_ptr, info_ptr, file_gamma); |
| 439 | } |
| 440 | #endif |
| 441 | |
| 442 | #if defined(PNG_READ_sBIT_SUPPORTED) |
| 443 | void |
| 444 | png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 445 | { |
| 446 | png_size_t truelen; |
| 447 | png_byte buf[4]; |
| 448 | |
| 449 | png_debug(1, "in png_handle_sBIT\n"); |
| 450 | |
| 451 | buf[0] = buf[1] = buf[2] = buf[3] = 0; |
| 452 | |
| 453 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 454 | png_error(png_ptr, "Missing IHDR before sBIT"); |
| 455 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 456 | { |
| 457 | png_warning(png_ptr, "Invalid sBIT after IDAT"); |
| 458 | png_crc_finish(png_ptr, length); |
| 459 | return; |
| 460 | } |
| 461 | else if (png_ptr->mode & PNG_HAVE_PLTE) |
| 462 | { |
| 463 | /* Should be an error, but we can cope with it */ |
| 464 | png_warning(png_ptr, "Out of place sBIT chunk"); |
| 465 | } |
| 466 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT) |
| 467 | { |
| 468 | png_warning(png_ptr, "Duplicate sBIT chunk"); |
| 469 | png_crc_finish(png_ptr, length); |
| 470 | return; |
| 471 | } |
| 472 | |
| 473 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 474 | truelen = 3; |
| 475 | else |
| 476 | truelen = (png_size_t)png_ptr->channels; |
| 477 | |
| 478 | if (length != truelen) |
| 479 | { |
| 480 | png_warning(png_ptr, "Incorrect sBIT chunk length"); |
| 481 | png_crc_finish(png_ptr, length); |
| 482 | return; |
| 483 | } |
| 484 | |
| 485 | png_crc_read(png_ptr, buf, truelen); |
| 486 | if (png_crc_finish(png_ptr, 0)) |
| 487 | return; |
| 488 | |
| 489 | if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) |
| 490 | { |
| 491 | png_ptr->sig_bit.red = buf[0]; |
| 492 | png_ptr->sig_bit.green = buf[1]; |
| 493 | png_ptr->sig_bit.blue = buf[2]; |
| 494 | png_ptr->sig_bit.alpha = buf[3]; |
| 495 | } |
| 496 | else |
| 497 | { |
| 498 | png_ptr->sig_bit.gray = buf[0]; |
| 499 | png_ptr->sig_bit.red = buf[0]; |
| 500 | png_ptr->sig_bit.green = buf[0]; |
| 501 | png_ptr->sig_bit.blue = buf[0]; |
| 502 | png_ptr->sig_bit.alpha = buf[1]; |
| 503 | } |
| 504 | png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit)); |
| 505 | } |
| 506 | #endif |
| 507 | |
| 508 | #if defined(PNG_READ_cHRM_SUPPORTED) |
| 509 | void |
| 510 | png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 511 | { |
| 512 | png_byte buf[4]; |
| 513 | png_uint_32 val; |
| 514 | float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y; |
| 515 | |
| 516 | png_debug(1, "in png_handle_cHRM\n"); |
| 517 | |
| 518 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 519 | png_error(png_ptr, "Missing IHDR before sBIT"); |
| 520 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 521 | { |
| 522 | png_warning(png_ptr, "Invalid cHRM after IDAT"); |
| 523 | png_crc_finish(png_ptr, length); |
| 524 | return; |
| 525 | } |
| 526 | else if (png_ptr->mode & PNG_HAVE_PLTE) |
| 527 | /* Should be an error, but we can cope with it */ |
| 528 | png_warning(png_ptr, "Missing PLTE before cHRM"); |
| 529 | |
| 530 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_cHRM |
| 531 | #if defined(PNG_READ_sRGB_SUPPORTED) |
| 532 | && !(info_ptr->valid & PNG_INFO_sRGB) |
| 533 | #endif |
| 534 | ) |
| 535 | { |
| 536 | png_warning(png_ptr, "Duplicate cHRM chunk"); |
| 537 | png_crc_finish(png_ptr, length); |
| 538 | return; |
| 539 | } |
| 540 | |
| 541 | if (length != 32) |
| 542 | { |
| 543 | png_warning(png_ptr, "Incorrect cHRM chunk length"); |
| 544 | png_crc_finish(png_ptr, length); |
| 545 | return; |
| 546 | } |
| 547 | |
| 548 | png_crc_read(png_ptr, buf, 4); |
| 549 | val = png_get_uint_32(buf); |
| 550 | white_x = (float)val / (float)100000.0; |
| 551 | |
| 552 | png_crc_read(png_ptr, buf, 4); |
| 553 | val = png_get_uint_32(buf); |
| 554 | white_y = (float)val / (float)100000.0; |
| 555 | |
| 556 | if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 || |
| 557 | white_x + white_y > 1.0) |
| 558 | { |
| 559 | png_warning(png_ptr, "Invalid cHRM white point"); |
| 560 | png_crc_finish(png_ptr, 24); |
| 561 | return; |
| 562 | } |
| 563 | |
| 564 | png_crc_read(png_ptr, buf, 4); |
| 565 | val = png_get_uint_32(buf); |
| 566 | red_x = (float)val / (float)100000.0; |
| 567 | |
| 568 | png_crc_read(png_ptr, buf, 4); |
| 569 | val = png_get_uint_32(buf); |
| 570 | red_y = (float)val / (float)100000.0; |
| 571 | |
| 572 | if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 || |
| 573 | red_x + red_y > 1.0) |
| 574 | { |
| 575 | png_warning(png_ptr, "Invalid cHRM red point"); |
| 576 | png_crc_finish(png_ptr, 16); |
| 577 | return; |
| 578 | } |
| 579 | |
| 580 | png_crc_read(png_ptr, buf, 4); |
| 581 | val = png_get_uint_32(buf); |
| 582 | green_x = (float)val / (float)100000.0; |
| 583 | |
| 584 | png_crc_read(png_ptr, buf, 4); |
| 585 | val = png_get_uint_32(buf); |
| 586 | green_y = (float)val / (float)100000.0; |
| 587 | |
| 588 | if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 || |
| 589 | green_x + green_y > 1.0) |
| 590 | { |
| 591 | png_warning(png_ptr, "Invalid cHRM green point"); |
| 592 | png_crc_finish(png_ptr, 8); |
| 593 | return; |
| 594 | } |
| 595 | |
| 596 | png_crc_read(png_ptr, buf, 4); |
| 597 | val = png_get_uint_32(buf); |
| 598 | blue_x = (float)val / (float)100000.0; |
| 599 | |
| 600 | png_crc_read(png_ptr, buf, 4); |
| 601 | val = png_get_uint_32(buf); |
| 602 | blue_y = (float)val / (float)100000.0; |
| 603 | |
| 604 | if (blue_x < (float)0 || blue_x > (float)0.8 || blue_y < (float)0 || |
| 605 | blue_y > (float)0.8 || blue_x + blue_y > (float)1.0) |
| 606 | { |
| 607 | png_warning(png_ptr, "Invalid cHRM blue point"); |
| 608 | png_crc_finish(png_ptr, 0); |
| 609 | return; |
| 610 | } |
| 611 | |
| 612 | if (png_crc_finish(png_ptr, 0)) |
| 613 | return; |
| 614 | |
| 615 | #if defined(PNG_READ_sRGB_SUPPORTED) |
| 616 | if (info_ptr->valid & PNG_INFO_sRGB) |
| 617 | { |
| 618 | if (fabs(white_x - (float).3127) > (float).001 || |
| 619 | fabs(white_y - (float).3290) > (float).001 || |
| 620 | fabs( red_x - (float).6400) > (float).001 || |
| 621 | fabs( red_y - (float).3300) > (float).001 || |
| 622 | fabs(green_x - (float).3000) > (float).001 || |
| 623 | fabs(green_y - (float).6000) > (float).001 || |
| 624 | fabs( blue_x - (float).1500) > (float).001 || |
| 625 | fabs( blue_y - (float).0600) > (float).001) |
| 626 | { |
| 627 | |
| 628 | png_warning(png_ptr, |
| 629 | "Ignoring incorrect cHRM value when sRGB is also present"); |
| 630 | #ifndef PNG_NO_CONSOLE_IO |
| 631 | fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n", |
| 632 | white_x, white_y, red_x, red_y); |
| 633 | fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n", |
| 634 | green_x, green_y, blue_x, blue_y); |
| 635 | #endif |
| 636 | } |
| 637 | return; |
| 638 | } |
| 639 | #endif /* PNG_READ_sRGB_SUPPORTED */ |
| 640 | |
| 641 | png_set_cHRM(png_ptr, info_ptr, |
| 642 | white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y); |
| 643 | } |
| 644 | #endif |
| 645 | |
| 646 | #if defined(PNG_READ_sRGB_SUPPORTED) |
| 647 | void |
| 648 | png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 649 | { |
| 650 | int intent; |
| 651 | png_byte buf[1]; |
| 652 | |
| 653 | png_debug(1, "in png_handle_sRGB\n"); |
| 654 | |
| 655 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 656 | png_error(png_ptr, "Missing IHDR before sRGB"); |
| 657 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 658 | { |
| 659 | png_warning(png_ptr, "Invalid sRGB after IDAT"); |
| 660 | png_crc_finish(png_ptr, length); |
| 661 | return; |
| 662 | } |
| 663 | else if (png_ptr->mode & PNG_HAVE_PLTE) |
| 664 | /* Should be an error, but we can cope with it */ |
| 665 | png_warning(png_ptr, "Out of place sRGB chunk"); |
| 666 | |
| 667 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sRGB) |
| 668 | { |
| 669 | png_warning(png_ptr, "Duplicate sRGB chunk"); |
| 670 | png_crc_finish(png_ptr, length); |
| 671 | return; |
| 672 | } |
| 673 | |
| 674 | if (length != 1) |
| 675 | { |
| 676 | png_warning(png_ptr, "Incorrect sRGB chunk length"); |
| 677 | png_crc_finish(png_ptr, length); |
| 678 | return; |
| 679 | } |
| 680 | |
| 681 | png_crc_read(png_ptr, buf, 1); |
| 682 | if (png_crc_finish(png_ptr, 0)) |
| 683 | return; |
| 684 | |
| 685 | intent = buf[0]; |
| 686 | /* check for bad intent */ |
| 687 | if (intent >= PNG_sRGB_INTENT_LAST) |
| 688 | { |
| 689 | png_warning(png_ptr, "Unknown sRGB intent"); |
| 690 | return; |
| 691 | } |
| 692 | |
| 693 | #if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) |
| 694 | if ((info_ptr->valid & PNG_INFO_gAMA)) |
| 695 | if((png_uint_32)(png_ptr->gamma*(float)100000.+.5) != (png_uint_32)45000L) |
| 696 | { |
| 697 | png_warning(png_ptr, |
| 698 | "Ignoring incorrect gAMA value when sRGB is also present"); |
| 699 | #ifndef PNG_NO_CONSOLE_IO |
| 700 | fprintf(stderr,"gamma=%f\n",png_ptr->gamma); |
| 701 | #endif |
| 702 | } |
| 703 | #endif /* PNG_READ_gAMA_SUPPORTED */ |
| 704 | |
| 705 | #ifdef PNG_READ_cHRM_SUPPORTED |
| 706 | if (info_ptr->valid & PNG_INFO_cHRM) |
| 707 | if (fabs(info_ptr->x_white - (float).3127) > (float).001 || |
| 708 | fabs(info_ptr->y_white - (float).3290) > (float).001 || |
| 709 | fabs( info_ptr->x_red - (float).6400) > (float).001 || |
| 710 | fabs( info_ptr->y_red - (float).3300) > (float).001 || |
| 711 | fabs(info_ptr->x_green - (float).3000) > (float).001 || |
| 712 | fabs(info_ptr->y_green - (float).6000) > (float).001 || |
| 713 | fabs( info_ptr->x_blue - (float).1500) > (float).001 || |
| 714 | fabs( info_ptr->y_blue - (float).0600) > (float).001) |
| 715 | { |
| 716 | png_warning(png_ptr, |
| 717 | "Ignoring incorrect cHRM value when sRGB is also present"); |
| 718 | } |
| 719 | #endif /* PNG_READ_cHRM_SUPPORTED */ |
| 720 | |
| 721 | png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent); |
| 722 | } |
| 723 | #endif /* PNG_READ_sRGB_SUPPORTED */ |
| 724 | |
| 725 | #if defined(PNG_READ_tRNS_SUPPORTED) |
| 726 | void |
| 727 | png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 728 | { |
| 729 | png_debug(1, "in png_handle_tRNS\n"); |
| 730 | |
| 731 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 732 | png_error(png_ptr, "Missing IHDR before tRNS"); |
| 733 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 734 | { |
| 735 | png_warning(png_ptr, "Invalid tRNS after IDAT"); |
| 736 | png_crc_finish(png_ptr, length); |
| 737 | return; |
| 738 | } |
| 739 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS) |
| 740 | { |
| 741 | png_warning(png_ptr, "Duplicate tRNS chunk"); |
| 742 | png_crc_finish(png_ptr, length); |
| 743 | return; |
| 744 | } |
| 745 | |
| 746 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 747 | { |
| 748 | if (!(png_ptr->mode & PNG_HAVE_PLTE)) |
| 749 | { |
| 750 | /* Should be an error, but we can cope with it */ |
| 751 | png_warning(png_ptr, "Missing PLTE before tRNS"); |
| 752 | } |
| 753 | else if (length > png_ptr->num_palette) |
| 754 | { |
| 755 | png_warning(png_ptr, "Incorrect tRNS chunk length"); |
| 756 | png_crc_finish(png_ptr, length); |
| 757 | return; |
| 758 | } |
| 759 | if (length == 0) |
| 760 | { |
| 761 | png_warning(png_ptr, "Zero length tRNS chunk"); |
| 762 | png_crc_finish(png_ptr, length); |
| 763 | return; |
| 764 | } |
| 765 | |
| 766 | png_ptr->trans = (png_bytep)png_malloc(png_ptr, length); |
| 767 | png_ptr->flags |= PNG_FLAG_FREE_TRANS; |
| 768 | png_crc_read(png_ptr, png_ptr->trans, (png_size_t)length); |
| 769 | png_ptr->num_trans = (png_uint_16)length; |
| 770 | } |
| 771 | else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) |
| 772 | { |
| 773 | png_byte buf[6]; |
| 774 | |
| 775 | if (length != 6) |
| 776 | { |
| 777 | png_warning(png_ptr, "Incorrect tRNS chunk length"); |
| 778 | png_crc_finish(png_ptr, length); |
| 779 | return; |
| 780 | } |
| 781 | |
| 782 | png_crc_read(png_ptr, buf, (png_size_t)length); |
| 783 | png_ptr->num_trans = 1; |
| 784 | png_ptr->trans_values.red = png_get_uint_16(buf); |
| 785 | png_ptr->trans_values.green = png_get_uint_16(buf + 2); |
| 786 | png_ptr->trans_values.blue = png_get_uint_16(buf + 4); |
| 787 | } |
| 788 | else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) |
| 789 | { |
| 790 | png_byte buf[6]; |
| 791 | |
| 792 | if (length != 2) |
| 793 | { |
| 794 | png_warning(png_ptr, "Incorrect tRNS chunk length"); |
| 795 | png_crc_finish(png_ptr, length); |
| 796 | return; |
| 797 | } |
| 798 | |
| 799 | png_crc_read(png_ptr, buf, 2); |
| 800 | png_ptr->num_trans = 1; |
| 801 | png_ptr->trans_values.gray = png_get_uint_16(buf); |
| 802 | } |
| 803 | else |
| 804 | { |
| 805 | png_warning(png_ptr, "tRNS chunk not allowed with alpha channel"); |
| 806 | png_crc_finish(png_ptr, length); |
| 807 | return; |
| 808 | } |
| 809 | |
| 810 | if (png_crc_finish(png_ptr, 0)) |
| 811 | return; |
| 812 | |
| 813 | png_set_tRNS(png_ptr, info_ptr, png_ptr->trans, png_ptr->num_trans, |
| 814 | &(png_ptr->trans_values)); |
| 815 | } |
| 816 | #endif |
| 817 | |
| 818 | #if defined(PNG_READ_bKGD_SUPPORTED) |
| 819 | void |
| 820 | png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 821 | { |
| 822 | png_size_t truelen; |
| 823 | png_byte buf[6]; |
| 824 | |
| 825 | png_debug(1, "in png_handle_bKGD\n"); |
| 826 | |
| 827 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 828 | png_error(png_ptr, "Missing IHDR before bKGD"); |
| 829 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 830 | { |
| 831 | png_warning(png_ptr, "Invalid bKGD after IDAT"); |
| 832 | png_crc_finish(png_ptr, length); |
| 833 | return; |
| 834 | } |
| 835 | else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && |
| 836 | !(png_ptr->mode & PNG_HAVE_PLTE)) |
| 837 | { |
| 838 | png_warning(png_ptr, "Missing PLTE before bKGD"); |
| 839 | png_crc_finish(png_ptr, length); |
| 840 | return; |
| 841 | } |
| 842 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_bKGD) |
| 843 | { |
| 844 | png_warning(png_ptr, "Duplicate bKGD chunk"); |
| 845 | png_crc_finish(png_ptr, length); |
| 846 | return; |
| 847 | } |
| 848 | |
| 849 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 850 | truelen = 1; |
| 851 | else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) |
| 852 | truelen = 6; |
| 853 | else |
| 854 | truelen = 2; |
| 855 | |
| 856 | if (length != truelen) |
| 857 | { |
| 858 | png_warning(png_ptr, "Incorrect bKGD chunk length"); |
| 859 | png_crc_finish(png_ptr, length); |
| 860 | return; |
| 861 | } |
| 862 | |
| 863 | png_crc_read(png_ptr, buf, truelen); |
| 864 | if (png_crc_finish(png_ptr, 0)) |
| 865 | return; |
| 866 | |
| 867 | /* We convert the index value into RGB components so that we can allow |
| 868 | * arbitrary RGB values for background when we have transparency, and |
| 869 | * so it is easy to determine the RGB values of the background color |
| 870 | * from the info_ptr struct. */ |
| 871 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 872 | { |
| 873 | png_ptr->background.index = buf[0]; |
| 874 | png_ptr->background.red = (png_uint_16)png_ptr->palette[buf[0]].red; |
| 875 | png_ptr->background.green = (png_uint_16)png_ptr->palette[buf[0]].green; |
| 876 | png_ptr->background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue; |
| 877 | } |
| 878 | else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */ |
| 879 | { |
| 880 | png_ptr->background.red = |
| 881 | png_ptr->background.green = |
| 882 | png_ptr->background.blue = |
| 883 | png_ptr->background.gray = png_get_uint_16(buf); |
| 884 | } |
| 885 | else |
| 886 | { |
| 887 | png_ptr->background.red = png_get_uint_16(buf); |
| 888 | png_ptr->background.green = png_get_uint_16(buf + 2); |
| 889 | png_ptr->background.blue = png_get_uint_16(buf + 4); |
| 890 | } |
| 891 | |
| 892 | png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background)); |
| 893 | } |
| 894 | #endif |
| 895 | |
| 896 | #if defined(PNG_READ_hIST_SUPPORTED) |
| 897 | void |
| 898 | png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 899 | { |
| 900 | int num, i; |
| 901 | |
| 902 | png_debug(1, "in png_handle_hIST\n"); |
| 903 | |
| 904 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 905 | png_error(png_ptr, "Missing IHDR before hIST"); |
| 906 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 907 | { |
| 908 | png_warning(png_ptr, "Invalid hIST after IDAT"); |
| 909 | png_crc_finish(png_ptr, length); |
| 910 | return; |
| 911 | } |
| 912 | else if (!(png_ptr->mode & PNG_HAVE_PLTE)) |
| 913 | { |
| 914 | png_warning(png_ptr, "Missing PLTE before hIST"); |
| 915 | png_crc_finish(png_ptr, length); |
| 916 | return; |
| 917 | } |
| 918 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_hIST) |
| 919 | { |
| 920 | png_warning(png_ptr, "Duplicate hIST chunk"); |
| 921 | png_crc_finish(png_ptr, length); |
| 922 | return; |
| 923 | } |
| 924 | |
| 925 | if (length != (png_uint_32)(2 * png_ptr->num_palette)) |
| 926 | { |
| 927 | png_warning(png_ptr, "Incorrect hIST chunk length"); |
| 928 | png_crc_finish(png_ptr, length); |
| 929 | return; |
| 930 | } |
| 931 | |
| 932 | num = (int)length / 2; |
| 933 | png_ptr->hist = (png_uint_16p)png_malloc(png_ptr, |
| 934 | (png_uint_32)(num * sizeof (png_uint_16))); |
| 935 | png_ptr->flags |= PNG_FLAG_FREE_HIST; |
| 936 | for (i = 0; i < num; i++) |
| 937 | { |
| 938 | png_byte buf[2]; |
| 939 | |
| 940 | png_crc_read(png_ptr, buf, 2); |
| 941 | png_ptr->hist[i] = png_get_uint_16(buf); |
| 942 | } |
| 943 | |
| 944 | if (png_crc_finish(png_ptr, 0)) |
| 945 | return; |
| 946 | |
| 947 | png_set_hIST(png_ptr, info_ptr, png_ptr->hist); |
| 948 | } |
| 949 | #endif |
| 950 | |
| 951 | #if defined(PNG_READ_pHYs_SUPPORTED) |
| 952 | void |
| 953 | png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 954 | { |
| 955 | png_byte buf[9]; |
| 956 | png_uint_32 res_x, res_y; |
| 957 | int unit_type; |
| 958 | |
| 959 | png_debug(1, "in png_handle_pHYs\n"); |
| 960 | |
| 961 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 962 | png_error(png_ptr, "Missing IHDR before pHYS"); |
| 963 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 964 | { |
| 965 | png_warning(png_ptr, "Invalid pHYS after IDAT"); |
| 966 | png_crc_finish(png_ptr, length); |
| 967 | return; |
| 968 | } |
| 969 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs) |
| 970 | { |
| 971 | png_warning(png_ptr, "Duplicate pHYS chunk"); |
| 972 | png_crc_finish(png_ptr, length); |
| 973 | return; |
| 974 | } |
| 975 | |
| 976 | if (length != 9) |
| 977 | { |
| 978 | png_warning(png_ptr, "Incorrect pHYs chunk length"); |
| 979 | png_crc_finish(png_ptr, length); |
| 980 | return; |
| 981 | } |
| 982 | |
| 983 | png_crc_read(png_ptr, buf, 9); |
| 984 | if (png_crc_finish(png_ptr, 0)) |
| 985 | return; |
| 986 | |
| 987 | res_x = png_get_uint_32(buf); |
| 988 | res_y = png_get_uint_32(buf + 4); |
| 989 | unit_type = buf[8]; |
| 990 | png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); |
| 991 | } |
| 992 | #endif |
| 993 | |
| 994 | #if defined(PNG_READ_oFFs_SUPPORTED) |
| 995 | void |
| 996 | png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 997 | { |
| 998 | png_byte buf[9]; |
| 999 | png_uint_32 offset_x, offset_y; |
| 1000 | int unit_type; |
| 1001 | |
| 1002 | png_debug(1, "in png_handle_oFFs\n"); |
| 1003 | |
| 1004 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 1005 | png_error(png_ptr, "Missing IHDR before oFFs"); |
| 1006 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 1007 | { |
| 1008 | png_warning(png_ptr, "Invalid oFFs after IDAT"); |
| 1009 | png_crc_finish(png_ptr, length); |
| 1010 | return; |
| 1011 | } |
| 1012 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_oFFs) |
| 1013 | { |
| 1014 | png_warning(png_ptr, "Duplicate oFFs chunk"); |
| 1015 | png_crc_finish(png_ptr, length); |
| 1016 | return; |
| 1017 | } |
| 1018 | |
| 1019 | if (length != 9) |
| 1020 | { |
| 1021 | png_warning(png_ptr, "Incorrect oFFs chunk length"); |
| 1022 | png_crc_finish(png_ptr, length); |
| 1023 | return; |
| 1024 | } |
| 1025 | |
| 1026 | png_crc_read(png_ptr, buf, 9); |
| 1027 | if (png_crc_finish(png_ptr, 0)) |
| 1028 | return; |
| 1029 | |
| 1030 | offset_x = png_get_uint_32(buf); |
| 1031 | offset_y = png_get_uint_32(buf + 4); |
| 1032 | unit_type = buf[8]; |
| 1033 | png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type); |
| 1034 | } |
| 1035 | #endif |
| 1036 | |
| 1037 | #if defined(PNG_READ_pCAL_SUPPORTED) |
| 1038 | /* read the pCAL chunk (png-scivis-19970203) */ |
| 1039 | void |
| 1040 | png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 1041 | { |
| 1042 | png_charp purpose; |
| 1043 | png_int_32 X0, X1; |
| 1044 | png_byte type, nparams; |
| 1045 | png_charp buf, units, endptr; |
| 1046 | png_charpp params; |
| 1047 | png_size_t slength; |
| 1048 | int i; |
| 1049 | |
| 1050 | png_debug(1, "in png_handle_pCAL\n"); |
| 1051 | |
| 1052 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 1053 | png_error(png_ptr, "Missing IHDR before pCAL"); |
| 1054 | else if (png_ptr->mode & PNG_HAVE_IDAT) |
| 1055 | { |
| 1056 | png_warning(png_ptr, "Invalid pCAL after IDAT"); |
| 1057 | png_crc_finish(png_ptr, length); |
| 1058 | return; |
| 1059 | } |
| 1060 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pCAL) |
| 1061 | { |
| 1062 | png_warning(png_ptr, "Duplicate pCAL chunk"); |
| 1063 | png_crc_finish(png_ptr, length); |
| 1064 | return; |
| 1065 | } |
| 1066 | |
| 1067 | png_debug1(2, "Allocating and reading pCAL chunk data (%d bytes)\n", |
| 1068 | length + 1); |
| 1069 | purpose = (png_charp)png_malloc(png_ptr, length + 1); |
| 1070 | slength = (png_size_t)length; |
| 1071 | png_crc_read(png_ptr, (png_bytep)purpose, slength); |
| 1072 | |
| 1073 | if (png_crc_finish(png_ptr, 0)) |
| 1074 | { |
| 1075 | png_free(png_ptr, purpose); |
| 1076 | return; |
| 1077 | } |
| 1078 | |
| 1079 | purpose[slength] = 0x00; /* null terminate the last string */ |
| 1080 | |
| 1081 | png_debug(3, "Finding end of pCAL purpose string\n"); |
| 1082 | for (buf = purpose; *buf; buf++) |
| 1083 | /* empty loop */ ; |
| 1084 | |
| 1085 | endptr = purpose + slength; |
| 1086 | |
| 1087 | /* We need to have at least 12 bytes after the purpose string |
| 1088 | in order to get the parameter information. */ |
| 1089 | if (endptr <= buf + 12) |
| 1090 | { |
| 1091 | png_warning(png_ptr, "Invalid pCAL data"); |
| 1092 | png_free(png_ptr, purpose); |
| 1093 | return; |
| 1094 | } |
| 1095 | |
| 1096 | png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n"); |
| 1097 | X0 = png_get_int_32((png_bytep)buf+1); |
| 1098 | X1 = png_get_int_32((png_bytep)buf+5); |
| 1099 | type = buf[9]; |
| 1100 | nparams = buf[10]; |
| 1101 | units = buf + 11; |
| 1102 | |
| 1103 | png_debug(3, "Checking pCAL equation type and number of parameters\n"); |
| 1104 | /* Check that we have the right number of parameters for known |
| 1105 | equation types. */ |
| 1106 | if ((type == PNG_EQUATION_LINEAR && nparams != 2) || |
| 1107 | (type == PNG_EQUATION_BASE_E && nparams != 3) || |
| 1108 | (type == PNG_EQUATION_ARBITRARY && nparams != 3) || |
| 1109 | (type == PNG_EQUATION_HYPERBOLIC && nparams != 4)) |
| 1110 | { |
| 1111 | png_warning(png_ptr, "Invalid pCAL parameters for equation type"); |
| 1112 | png_free(png_ptr, purpose); |
| 1113 | return; |
| 1114 | } |
| 1115 | else if (type >= PNG_EQUATION_LAST) |
| 1116 | { |
| 1117 | png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); |
| 1118 | } |
| 1119 | |
| 1120 | for (buf = units; *buf; buf++) |
| 1121 | /* Empty loop to move past the units string. */ ; |
| 1122 | |
| 1123 | png_debug(3, "Allocating pCAL parameters array\n"); |
| 1124 | params = (png_charpp)png_malloc(png_ptr, (png_uint_32)(nparams |
| 1125 | *sizeof(png_charp))) ; |
| 1126 | |
| 1127 | /* Get pointers to the start of each parameter string. */ |
| 1128 | for (i = 0; i < (int)nparams; i++) |
| 1129 | { |
| 1130 | buf++; /* Skip the null string terminator from previous parameter. */ |
| 1131 | |
| 1132 | png_debug1(3, "Reading pCAL parameter %d\n", i); |
| 1133 | for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++) |
| 1134 | /* Empty loop to move past each parameter string */ ; |
| 1135 | |
| 1136 | /* Make sure we haven't run out of data yet */ |
| 1137 | if (buf > endptr) |
| 1138 | { |
| 1139 | png_warning(png_ptr, "Invalid pCAL data"); |
| 1140 | png_free(png_ptr, purpose); |
| 1141 | png_free(png_ptr, params); |
| 1142 | return; |
| 1143 | } |
| 1144 | } |
| 1145 | |
| 1146 | png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams, |
| 1147 | units, params); |
| 1148 | |
| 1149 | png_free(png_ptr, purpose); |
| 1150 | png_free(png_ptr, params); |
| 1151 | } |
| 1152 | #endif |
| 1153 | |
| 1154 | #if defined(PNG_READ_tIME_SUPPORTED) |
| 1155 | void |
| 1156 | png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 1157 | { |
| 1158 | png_byte buf[7]; |
| 1159 | png_time mod_time; |
| 1160 | |
| 1161 | png_debug(1, "in png_handle_tIME\n"); |
| 1162 | |
| 1163 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 1164 | png_error(png_ptr, "Out of place tIME chunk"); |
| 1165 | else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME) |
| 1166 | { |
| 1167 | png_warning(png_ptr, "Duplicate tIME chunk"); |
| 1168 | png_crc_finish(png_ptr, length); |
| 1169 | return; |
| 1170 | } |
| 1171 | |
| 1172 | if (png_ptr->mode & PNG_HAVE_IDAT) |
| 1173 | png_ptr->mode |= PNG_AFTER_IDAT; |
| 1174 | |
| 1175 | if (length != 7) |
| 1176 | { |
| 1177 | png_warning(png_ptr, "Incorrect tIME chunk length"); |
| 1178 | png_crc_finish(png_ptr, length); |
| 1179 | return; |
| 1180 | } |
| 1181 | |
| 1182 | png_crc_read(png_ptr, buf, 7); |
| 1183 | if (png_crc_finish(png_ptr, 0)) |
| 1184 | return; |
| 1185 | |
| 1186 | mod_time.second = buf[6]; |
| 1187 | mod_time.minute = buf[5]; |
| 1188 | mod_time.hour = buf[4]; |
| 1189 | mod_time.day = buf[3]; |
| 1190 | mod_time.month = buf[2]; |
| 1191 | mod_time.year = png_get_uint_16(buf); |
| 1192 | |
| 1193 | png_set_tIME(png_ptr, info_ptr, &mod_time); |
| 1194 | } |
| 1195 | #endif |
| 1196 | |
| 1197 | #if defined(PNG_READ_tEXt_SUPPORTED) |
| 1198 | /* Note: this does not properly handle chunks that are > 64K under DOS */ |
| 1199 | void |
| 1200 | png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 1201 | { |
| 1202 | png_textp text_ptr; |
| 1203 | png_charp key; |
| 1204 | png_charp text; |
| 1205 | png_uint_32 skip = 0; |
| 1206 | png_size_t slength; |
| 1207 | |
| 1208 | png_debug(1, "in png_handle_tEXt\n"); |
| 1209 | |
| 1210 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 1211 | png_error(png_ptr, "Missing IHDR before tEXt"); |
| 1212 | |
| 1213 | if (png_ptr->mode & PNG_HAVE_IDAT) |
| 1214 | png_ptr->mode |= PNG_AFTER_IDAT; |
| 1215 | |
| 1216 | #ifdef PNG_MAX_MALLOC_64K |
| 1217 | if (length > (png_uint_32)65535L) |
| 1218 | { |
| 1219 | png_warning(png_ptr, "tEXt chunk too large to fit in memory"); |
| 1220 | skip = length - (png_uint_32)65535L; |
| 1221 | length = (png_uint_32)65535L; |
| 1222 | } |
| 1223 | #endif |
| 1224 | |
| 1225 | key = (png_charp)png_malloc(png_ptr, length + 1); |
| 1226 | slength = (png_size_t)length; |
| 1227 | png_crc_read(png_ptr, (png_bytep)key, slength); |
| 1228 | |
| 1229 | if (png_crc_finish(png_ptr, skip)) |
| 1230 | { |
| 1231 | png_free(png_ptr, key); |
| 1232 | return; |
| 1233 | } |
| 1234 | |
| 1235 | key[slength] = 0x00; |
| 1236 | |
| 1237 | for (text = key; *text; text++) |
| 1238 | /* empty loop to find end of key */ ; |
| 1239 | |
| 1240 | if (text != key + slength) |
| 1241 | text++; |
| 1242 | |
| 1243 | text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); |
| 1244 | text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; |
| 1245 | text_ptr->key = key; |
| 1246 | text_ptr->text = text; |
| 1247 | |
| 1248 | png_set_text(png_ptr, info_ptr, text_ptr, 1); |
| 1249 | |
| 1250 | png_free(png_ptr, text_ptr); |
| 1251 | } |
| 1252 | #endif |
| 1253 | |
| 1254 | #if defined(PNG_READ_zTXt_SUPPORTED) |
| 1255 | /* note: this does not correctly handle chunks that are > 64K under DOS */ |
| 1256 | void |
| 1257 | png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 1258 | { |
| 1259 | static char msg[] = "Error decoding zTXt chunk"; |
| 1260 | png_textp text_ptr; |
| 1261 | png_charp key; |
| 1262 | png_charp text; |
| 1263 | int comp_type = PNG_TEXT_COMPRESSION_NONE; |
| 1264 | png_size_t slength; |
| 1265 | |
| 1266 | png_debug(1, "in png_handle_zTXt\n"); |
| 1267 | |
| 1268 | if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| 1269 | png_error(png_ptr, "Missing IHDR before zTXt"); |
| 1270 | |
| 1271 | if (png_ptr->mode & PNG_HAVE_IDAT) |
| 1272 | png_ptr->mode |= PNG_AFTER_IDAT; |
| 1273 | |
| 1274 | #ifdef PNG_MAX_MALLOC_64K |
| 1275 | /* We will no doubt have problems with chunks even half this size, but |
| 1276 | there is no hard and fast rule to tell us where to stop. */ |
| 1277 | if (length > (png_uint_32)65535L) |
| 1278 | { |
| 1279 | png_warning(png_ptr,"zTXt chunk too large to fit in memory"); |
| 1280 | png_crc_finish(png_ptr, length); |
| 1281 | return; |
| 1282 | } |
| 1283 | #endif |
| 1284 | |
| 1285 | key = (png_charp)png_malloc(png_ptr, length + 1); |
| 1286 | slength = (png_size_t)length; |
| 1287 | png_crc_read(png_ptr, (png_bytep)key, slength); |
| 1288 | if (png_crc_finish(png_ptr, 0)) |
| 1289 | { |
| 1290 | png_free(png_ptr, key); |
| 1291 | return; |
| 1292 | } |
| 1293 | |
| 1294 | key[slength] = 0x00; |
| 1295 | |
| 1296 | for (text = key; *text; text++) |
| 1297 | /* empty loop */ ; |
| 1298 | |
| 1299 | /* zTXt must have some text after the keyword */ |
| 1300 | if (text == key + slength) |
| 1301 | { |
| 1302 | png_warning(png_ptr, "Zero length zTXt chunk"); |
| 1303 | } |
| 1304 | else if ((comp_type = *(++text)) == PNG_TEXT_COMPRESSION_zTXt) |
| 1305 | { |
| 1306 | png_size_t text_size, key_size; |
| 1307 | text++; |
| 1308 | |
| 1309 | png_ptr->zstream.next_in = (png_bytep)text; |
| 1310 | png_ptr->zstream.avail_in = (uInt)(length - (text - key)); |
| 1311 | png_ptr->zstream.next_out = png_ptr->zbuf; |
| 1312 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| 1313 | |
| 1314 | key_size = (png_size_t)(text - key); |
| 1315 | text_size = 0; |
| 1316 | text = NULL; |
| 1317 | |
| 1318 | while (png_ptr->zstream.avail_in) |
| 1319 | { |
| 1320 | int ret; |
| 1321 | |
| 1322 | ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); |
| 1323 | if (ret != Z_OK && ret != Z_STREAM_END) |
| 1324 | { |
| 1325 | if (png_ptr->zstream.msg != NULL) |
| 1326 | png_warning(png_ptr, png_ptr->zstream.msg); |
| 1327 | else |
| 1328 | png_warning(png_ptr, msg); |
| 1329 | inflateReset(&png_ptr->zstream); |
| 1330 | png_ptr->zstream.avail_in = 0; |
| 1331 | |
| 1332 | if (text == NULL) |
| 1333 | { |
| 1334 | text_size = key_size + sizeof(msg) + 1; |
| 1335 | text = (png_charp)png_malloc(png_ptr, (png_uint_32)text_size); |
| 1336 | png_memcpy(text, key, key_size); |
| 1337 | } |
| 1338 | |
| 1339 | text[text_size - 1] = 0x00; |
| 1340 | |
| 1341 | /* Copy what we can of the error message into the text chunk */ |
| 1342 | text_size = (png_size_t)(slength - (text - key) - 1); |
| 1343 | text_size = sizeof(msg) > text_size ? text_size : sizeof(msg); |
| 1344 | png_memcpy(text + key_size, msg, text_size + 1); |
| 1345 | break; |
| 1346 | } |
| 1347 | if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END) |
| 1348 | { |
| 1349 | if (text == NULL) |
| 1350 | { |
| 1351 | text = (png_charp)png_malloc(png_ptr, |
| 1352 | (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out |
| 1353 | + key_size + 1)); |
| 1354 | png_memcpy(text + key_size, png_ptr->zbuf, |
| 1355 | png_ptr->zbuf_size - png_ptr->zstream.avail_out); |
| 1356 | png_memcpy(text, key, key_size); |
| 1357 | text_size = key_size + png_ptr->zbuf_size - |
| 1358 | png_ptr->zstream.avail_out; |
| 1359 | *(text + text_size) = 0x00; |
| 1360 | } |
| 1361 | else |
| 1362 | { |
| 1363 | png_charp tmp; |
| 1364 | |
| 1365 | tmp = text; |
| 1366 | text = (png_charp)png_malloc(png_ptr, (png_uint_32)(text_size + |
| 1367 | png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1)); |
| 1368 | png_memcpy(text, tmp, text_size); |
| 1369 | png_free(png_ptr, tmp); |
| 1370 | png_memcpy(text + text_size, png_ptr->zbuf, |
| 1371 | (png_ptr->zbuf_size - png_ptr->zstream.avail_out)); |
| 1372 | text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; |
| 1373 | *(text + text_size) = 0x00; |
| 1374 | } |
| 1375 | if (ret != Z_STREAM_END) |
| 1376 | { |
| 1377 | png_ptr->zstream.next_out = png_ptr->zbuf; |
| 1378 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| 1379 | } |
| 1380 | else |
| 1381 | { |
| 1382 | break; |
| 1383 | } |
| 1384 | } |
| 1385 | } |
| 1386 | |
| 1387 | inflateReset(&png_ptr->zstream); |
| 1388 | png_ptr->zstream.avail_in = 0; |
| 1389 | |
| 1390 | png_free(png_ptr, key); |
| 1391 | key = text; |
| 1392 | text += key_size; |
| 1393 | } |
| 1394 | else /* if (comp_type >= PNG_TEXT_COMPRESSION_LAST) */ |
| 1395 | { |
| 1396 | png_size_t text_size; |
| 1397 | #if !defined(PNG_NO_STDIO) |
| 1398 | char umsg[50]; |
| 1399 | |
| 1400 | sprintf(umsg, "Unknown zTXt compression type %d", comp_type); |
| 1401 | png_warning(png_ptr, umsg); |
| 1402 | #else |
| 1403 | png_warning(png_ptr, "Unknown zTXt compression type"); |
| 1404 | #endif |
| 1405 | |
| 1406 | /* Copy what we can of the error message into the text chunk */ |
| 1407 | text_size = (png_size_t)(slength - (text - key) - 1); |
| 1408 | text_size = sizeof(msg) > text_size ? text_size : sizeof(msg); |
| 1409 | png_memcpy(text, msg, text_size + 1); |
| 1410 | } |
| 1411 | |
| 1412 | text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); |
| 1413 | text_ptr->compression = comp_type; |
| 1414 | text_ptr->key = key; |
| 1415 | text_ptr->text = text; |
| 1416 | |
| 1417 | png_set_text(png_ptr, info_ptr, text_ptr, 1); |
| 1418 | |
| 1419 | png_free(png_ptr, text_ptr); |
| 1420 | } |
| 1421 | #endif |
| 1422 | |
| 1423 | /* This function is called when we haven't found a handler for a |
| 1424 | chunk. If there isn't a problem with the chunk itself (ie bad |
| 1425 | chunk name, CRC, or a critical chunk), the chunk is silently ignored. */ |
| 1426 | void |
| 1427 | png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| 1428 | { |
| 1429 | png_debug(1, "in png_handle_unknown\n"); |
| 1430 | |
| 1431 | /* In the future we can have code here that calls user-supplied |
| 1432 | * callback functions for unknown chunks before they are ignored or |
| 1433 | * cause an error. |
| 1434 | */ |
| 1435 | png_check_chunk_name(png_ptr, png_ptr->chunk_name); |
| 1436 | |
| 1437 | if (!(png_ptr->chunk_name[0] & 0x20)) |
| 1438 | { |
| 1439 | png_chunk_error(png_ptr, "unknown critical chunk"); |
| 1440 | |
| 1441 | /* to quiet compiler warnings about unused info_ptr */ |
| 1442 | if (info_ptr == NULL) |
| 1443 | return; |
| 1444 | } |
| 1445 | |
| 1446 | if (png_ptr->mode & PNG_HAVE_IDAT) |
| 1447 | png_ptr->mode |= PNG_AFTER_IDAT; |
| 1448 | |
| 1449 | png_crc_finish(png_ptr, length); |
| 1450 | |
| 1451 | } |
| 1452 | |
| 1453 | /* This function is called to verify that a chunk name is valid. |
| 1454 | This function can't have the "critical chunk check" incorporated |
| 1455 | into it, since in the future we will need to be able to call user |
| 1456 | functions to handle unknown critical chunks after we check that |
| 1457 | the chunk name itself is valid. */ |
| 1458 | |
| 1459 | #define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97)) |
| 1460 | |
| 1461 | void |
| 1462 | png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name) |
| 1463 | { |
| 1464 | png_debug(1, "in png_check_chunk_name\n"); |
| 1465 | if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) || |
| 1466 | isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3])) |
| 1467 | { |
| 1468 | png_chunk_error(png_ptr, "invalid chunk type"); |
| 1469 | } |
| 1470 | } |
| 1471 | |
| 1472 | /* Combines the row recently read in with the existing pixels in the |
| 1473 | row. This routine takes care of alpha and transparency if requested. |
| 1474 | This routine also handles the two methods of progressive display |
| 1475 | of interlaced images, depending on the mask value. |
| 1476 | The mask value describes which pixels are to be combined with |
| 1477 | the row. The pattern always repeats every 8 pixels, so just 8 |
| 1478 | bits are needed. A one indicates the pixel is to be combined, |
| 1479 | a zero indicates the pixel is to be skipped. This is in addition |
| 1480 | to any alpha or transparency value associated with the pixel. If |
| 1481 | you want all pixels to be combined, pass 0xff (255) in mask. */ |
| 1482 | void |
| 1483 | png_combine_row(png_structp png_ptr, png_bytep row, |
| 1484 | int mask) |
| 1485 | { |
| 1486 | png_debug(1,"in png_combine_row\n"); |
| 1487 | if (mask == 0xff) |
| 1488 | { |
| 1489 | png_memcpy(row, png_ptr->row_buf + 1, |
| 1490 | (png_size_t)((png_ptr->width * |
| 1491 | png_ptr->row_info.pixel_depth + 7) >> 3)); |
| 1492 | } |
| 1493 | else |
| 1494 | { |
| 1495 | switch (png_ptr->row_info.pixel_depth) |
| 1496 | { |
| 1497 | case 1: |
| 1498 | { |
| 1499 | png_bytep sp = png_ptr->row_buf + 1; |
| 1500 | png_bytep dp = row; |
| 1501 | int s_inc, s_start, s_end; |
| 1502 | int m = 0x80; |
| 1503 | int shift; |
| 1504 | png_uint_32 i; |
| 1505 | png_uint_32 row_width = png_ptr->width; |
| 1506 | |
| 1507 | #if defined(PNG_READ_PACKSWAP_SUPPORTED) |
| 1508 | if (png_ptr->transformations & PNG_PACKSWAP) |
| 1509 | { |
| 1510 | s_start = 0; |
| 1511 | s_end = 7; |
| 1512 | s_inc = 1; |
| 1513 | } |
| 1514 | else |
| 1515 | #endif |
| 1516 | { |
| 1517 | s_start = 7; |
| 1518 | s_end = 0; |
| 1519 | s_inc = -1; |
| 1520 | } |
| 1521 | |
| 1522 | shift = s_start; |
| 1523 | |
| 1524 | for (i = 0; i < row_width; i++) |
| 1525 | { |
| 1526 | if (m & mask) |
| 1527 | { |
| 1528 | int value; |
| 1529 | |
| 1530 | value = (*sp >> shift) & 0x1; |
| 1531 | *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); |
| 1532 | *dp |= (png_byte)(value << shift); |
| 1533 | } |
| 1534 | |
| 1535 | if (shift == s_end) |
| 1536 | { |
| 1537 | shift = s_start; |
| 1538 | sp++; |
| 1539 | dp++; |
| 1540 | } |
| 1541 | else |
| 1542 | shift += s_inc; |
| 1543 | |
| 1544 | if (m == 1) |
| 1545 | m = 0x80; |
| 1546 | else |
| 1547 | m >>= 1; |
| 1548 | } |
| 1549 | break; |
| 1550 | } |
| 1551 | case 2: |
| 1552 | { |
| 1553 | png_bytep sp = png_ptr->row_buf + 1; |
| 1554 | png_bytep dp = row; |
| 1555 | int s_start, s_end, s_inc; |
| 1556 | int m = 0x80; |
| 1557 | int shift; |
| 1558 | png_uint_32 i; |
| 1559 | png_uint_32 row_width = png_ptr->width; |
| 1560 | int value; |
| 1561 | |
| 1562 | #if defined(PNG_READ_PACKSWAP_SUPPORTED) |
| 1563 | if (png_ptr->transformations & PNG_PACKSWAP) |
| 1564 | { |
| 1565 | s_start = 0; |
| 1566 | s_end = 6; |
| 1567 | s_inc = 2; |
| 1568 | } |
| 1569 | else |
| 1570 | #endif |
| 1571 | { |
| 1572 | s_start = 6; |
| 1573 | s_end = 0; |
| 1574 | s_inc = -2; |
| 1575 | } |
| 1576 | |
| 1577 | shift = s_start; |
| 1578 | |
| 1579 | for (i = 0; i < row_width; i++) |
| 1580 | { |
| 1581 | if (m & mask) |
| 1582 | { |
| 1583 | value = (*sp >> shift) & 0x3; |
| 1584 | *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
| 1585 | *dp |= (png_byte)(value << shift); |
| 1586 | } |
| 1587 | |
| 1588 | if (shift == s_end) |
| 1589 | { |
| 1590 | shift = s_start; |
| 1591 | sp++; |
| 1592 | dp++; |
| 1593 | } |
| 1594 | else |
| 1595 | shift += s_inc; |
| 1596 | if (m == 1) |
| 1597 | m = 0x80; |
| 1598 | else |
| 1599 | m >>= 1; |
| 1600 | } |
| 1601 | break; |
| 1602 | } |
| 1603 | case 4: |
| 1604 | { |
| 1605 | png_bytep sp = png_ptr->row_buf + 1; |
| 1606 | png_bytep dp = row; |
| 1607 | int s_start, s_end, s_inc; |
| 1608 | int m = 0x80; |
| 1609 | int shift; |
| 1610 | png_uint_32 i; |
| 1611 | png_uint_32 row_width = png_ptr->width; |
| 1612 | int value; |
| 1613 | |
| 1614 | #if defined(PNG_READ_PACKSWAP_SUPPORTED) |
| 1615 | if (png_ptr->transformations & PNG_PACKSWAP) |
| 1616 | { |
| 1617 | s_start = 0; |
| 1618 | s_end = 4; |
| 1619 | s_inc = 4; |
| 1620 | } |
| 1621 | else |
| 1622 | #endif |
| 1623 | { |
| 1624 | s_start = 4; |
| 1625 | s_end = 0; |
| 1626 | s_inc = -4; |
| 1627 | } |
| 1628 | shift = s_start; |
| 1629 | |
| 1630 | for (i = 0; i < row_width; i++) |
| 1631 | { |
| 1632 | if (m & mask) |
| 1633 | { |
| 1634 | value = (*sp >> shift) & 0xf; |
| 1635 | *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
| 1636 | *dp |= (png_byte)(value << shift); |
| 1637 | } |
| 1638 | |
| 1639 | if (shift == s_end) |
| 1640 | { |
| 1641 | shift = s_start; |
| 1642 | sp++; |
| 1643 | dp++; |
| 1644 | } |
| 1645 | else |
| 1646 | shift += s_inc; |
| 1647 | if (m == 1) |
| 1648 | m = 0x80; |
| 1649 | else |
| 1650 | m >>= 1; |
| 1651 | } |
| 1652 | break; |
| 1653 | } |
| 1654 | default: |
| 1655 | { |
| 1656 | png_bytep sp = png_ptr->row_buf + 1; |
| 1657 | png_bytep dp = row; |
| 1658 | png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3); |
| 1659 | png_uint_32 i; |
| 1660 | png_uint_32 row_width = png_ptr->width; |
| 1661 | png_byte m = 0x80; |
| 1662 | |
| 1663 | |
| 1664 | for (i = 0; i < row_width; i++) |
| 1665 | { |
| 1666 | if (m & mask) |
| 1667 | { |
| 1668 | png_memcpy(dp, sp, pixel_bytes); |
| 1669 | } |
| 1670 | |
| 1671 | sp += pixel_bytes; |
| 1672 | dp += pixel_bytes; |
| 1673 | |
| 1674 | if (m == 1) |
| 1675 | m = 0x80; |
| 1676 | else |
| 1677 | m >>= 1; |
| 1678 | } |
| 1679 | break; |
| 1680 | } |
| 1681 | } |
| 1682 | } |
| 1683 | } |
| 1684 | |
| 1685 | #if defined(PNG_READ_INTERLACING_SUPPORTED) |
| 1686 | void |
| 1687 | png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, |
| 1688 | png_uint_32 transformations) |
| 1689 | { |
| 1690 | png_debug(1,"in png_do_read_interlace\n"); |
| 1691 | if (row != NULL && row_info != NULL) |
| 1692 | { |
| 1693 | png_uint_32 final_width; |
| 1694 | |
| 1695 | final_width = row_info->width * png_pass_inc[pass]; |
| 1696 | |
| 1697 | switch (row_info->pixel_depth) |
| 1698 | { |
| 1699 | case 1: |
| 1700 | { |
| 1701 | png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3); |
| 1702 | png_bytep dp = row + (png_size_t)((final_width - 1) >> 3); |
| 1703 | int sshift, dshift; |
| 1704 | int s_start, s_end, s_inc; |
| 1705 | int jstop = png_pass_inc[pass]; |
| 1706 | png_byte v; |
| 1707 | png_uint_32 i; |
| 1708 | int j; |
| 1709 | |
| 1710 | #if defined(PNG_READ_PACKSWAP_SUPPORTED) |
| 1711 | if (transformations & PNG_PACKSWAP) |
| 1712 | { |
| 1713 | sshift = (int)((row_info->width + 7) & 7); |
| 1714 | dshift = (int)((final_width + 7) & 7); |
| 1715 | s_start = 7; |
| 1716 | s_end = 0; |
| 1717 | s_inc = -1; |
| 1718 | } |
| 1719 | else |
| 1720 | #endif |
| 1721 | { |
| 1722 | sshift = 7 - (int)((row_info->width + 7) & 7); |
| 1723 | dshift = 7 - (int)((final_width + 7) & 7); |
| 1724 | s_start = 0; |
| 1725 | s_end = 7; |
| 1726 | s_inc = 1; |
| 1727 | } |
| 1728 | |
| 1729 | for (i = 0; i < row_info->width; i++) |
| 1730 | { |
| 1731 | v = (png_byte)((*sp >> sshift) & 0x1); |
| 1732 | for (j = 0; j < jstop; j++) |
| 1733 | { |
| 1734 | *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff); |
| 1735 | *dp |= (png_byte)(v << dshift); |
| 1736 | if (dshift == s_end) |
| 1737 | { |
| 1738 | dshift = s_start; |
| 1739 | dp--; |
| 1740 | } |
| 1741 | else |
| 1742 | dshift += s_inc; |
| 1743 | } |
| 1744 | if (sshift == s_end) |
| 1745 | { |
| 1746 | sshift = s_start; |
| 1747 | sp--; |
| 1748 | } |
| 1749 | else |
| 1750 | sshift += s_inc; |
| 1751 | } |
| 1752 | break; |
| 1753 | } |
| 1754 | case 2: |
| 1755 | { |
| 1756 | png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2); |
| 1757 | png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2); |
| 1758 | int sshift, dshift; |
| 1759 | int s_start, s_end, s_inc; |
| 1760 | int jstop = png_pass_inc[pass]; |
| 1761 | png_uint_32 i; |
| 1762 | |
| 1763 | #if defined(PNG_READ_PACKSWAP_SUPPORTED) |
| 1764 | if (transformations & PNG_PACKSWAP) |
| 1765 | { |
| 1766 | sshift = (int)(((row_info->width + 3) & 3) << 1); |
| 1767 | dshift = (int)(((final_width + 3) & 3) << 1); |
| 1768 | s_start = 6; |
| 1769 | s_end = 0; |
| 1770 | s_inc = -2; |
| 1771 | } |
| 1772 | else |
| 1773 | #endif |
| 1774 | { |
| 1775 | sshift = (int)((3 - ((row_info->width + 3) & 3)) << 1); |
| 1776 | dshift = (int)((3 - ((final_width + 3) & 3)) << 1); |
| 1777 | s_start = 0; |
| 1778 | s_end = 6; |
| 1779 | s_inc = 2; |
| 1780 | } |
| 1781 | |
| 1782 | for (i = 0; i < row_info->width; i++) |
| 1783 | { |
| 1784 | png_byte v; |
| 1785 | int j; |
| 1786 | |
| 1787 | v = (png_byte)((*sp >> sshift) & 0x3); |
| 1788 | for (j = 0; j < jstop; j++) |
| 1789 | { |
| 1790 | *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff); |
| 1791 | *dp |= (png_byte)(v << dshift); |
| 1792 | if (dshift == s_end) |
| 1793 | { |
| 1794 | dshift = s_start; |
| 1795 | dp--; |
| 1796 | } |
| 1797 | else |
| 1798 | dshift += s_inc; |
| 1799 | } |
| 1800 | if (sshift == s_end) |
| 1801 | { |
| 1802 | sshift = s_start; |
| 1803 | sp--; |
| 1804 | } |
| 1805 | else |
| 1806 | sshift += s_inc; |
| 1807 | } |
| 1808 | break; |
| 1809 | } |
| 1810 | case 4: |
| 1811 | { |
| 1812 | png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1); |
| 1813 | png_bytep dp = row + (png_size_t)((final_width - 1) >> 1); |
| 1814 | int sshift, dshift; |
| 1815 | int s_start, s_end, s_inc; |
| 1816 | png_uint_32 i; |
| 1817 | int jstop = png_pass_inc[pass]; |
| 1818 | |
| 1819 | #if defined(PNG_READ_PACKSWAP_SUPPORTED) |
| 1820 | if (transformations & PNG_PACKSWAP) |
| 1821 | { |
| 1822 | sshift = (int)(((row_info->width + 1) & 1) << 2); |
| 1823 | dshift = (int)(((final_width + 1) & 1) << 2); |
| 1824 | s_start = 4; |
| 1825 | s_end = 0; |
| 1826 | s_inc = -4; |
| 1827 | } |
| 1828 | else |
| 1829 | #endif |
| 1830 | { |
| 1831 | sshift = (int)((1 - ((row_info->width + 1) & 1)) << 2); |
| 1832 | dshift = (int)((1 - ((final_width + 1) & 1)) << 2); |
| 1833 | s_start = 0; |
| 1834 | s_end = 4; |
| 1835 | s_inc = 4; |
| 1836 | } |
| 1837 | |
| 1838 | for (i = 0; i < row_info->width; i++) |
| 1839 | { |
| 1840 | png_byte v = (png_byte)((*sp >> sshift) & 0xf); |
| 1841 | int j; |
| 1842 | |
| 1843 | for (j = 0; j < jstop; j++) |
| 1844 | { |
| 1845 | *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff); |
| 1846 | *dp |= (png_byte)(v << dshift); |
| 1847 | if (dshift == s_end) |
| 1848 | { |
| 1849 | dshift = s_start; |
| 1850 | dp--; |
| 1851 | } |
| 1852 | else |
| 1853 | dshift += s_inc; |
| 1854 | } |
| 1855 | if (sshift == s_end) |
| 1856 | { |
| 1857 | sshift = s_start; |
| 1858 | sp--; |
| 1859 | } |
| 1860 | else |
| 1861 | sshift += s_inc; |
| 1862 | } |
| 1863 | break; |
| 1864 | } |
| 1865 | default: |
| 1866 | { |
| 1867 | png_size_t pixel_bytes = (row_info->pixel_depth >> 3); |
| 1868 | png_bytep sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes; |
| 1869 | png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes; |
| 1870 | int jstop = png_pass_inc[pass]; |
| 1871 | png_uint_32 i; |
| 1872 | |
| 1873 | for (i = 0; i < row_info->width; i++) |
| 1874 | { |
| 1875 | png_byte v[8]; |
| 1876 | int j; |
| 1877 | |
| 1878 | png_memcpy(v, sp, pixel_bytes); |
| 1879 | for (j = 0; j < jstop; j++) |
| 1880 | { |
| 1881 | png_memcpy(dp, v, pixel_bytes); |
| 1882 | dp -= pixel_bytes; |
| 1883 | } |
| 1884 | sp -= pixel_bytes; |
| 1885 | } |
| 1886 | break; |
| 1887 | } |
| 1888 | } |
| 1889 | row_info->width = final_width; |
| 1890 | row_info->rowbytes = ((final_width * |
| 1891 | (png_uint_32)row_info->pixel_depth + 7) >> 3); |
| 1892 | } |
| 1893 | } |
| 1894 | #endif |
| 1895 | |
| 1896 | void |
| 1897 | png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row, |
| 1898 | png_bytep prev_row, int filter) |
| 1899 | { |
| 1900 | png_debug(1, "in png_read_filter_row\n"); |
| 1901 | png_debug2(2,"row = %d, filter = %d\n", png_ptr->row_number, filter); |
| 1902 | |
| 1903 | |
| 1904 | switch (filter) |
| 1905 | { |
| 1906 | case PNG_FILTER_VALUE_NONE: |
| 1907 | break; |
| 1908 | case PNG_FILTER_VALUE_SUB: |
| 1909 | { |
| 1910 | png_uint_32 i; |
| 1911 | png_uint_32 istop = row_info->rowbytes; |
| 1912 | png_uint_32 bpp = (row_info->pixel_depth + 7) / 8; |
| 1913 | png_bytep rp = row + bpp; |
| 1914 | png_bytep lp = row; |
| 1915 | |
| 1916 | for (i = bpp; i < istop; i++) |
| 1917 | { |
| 1918 | *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff); |
| 1919 | rp++; |
| 1920 | } |
| 1921 | break; |
| 1922 | } |
| 1923 | case PNG_FILTER_VALUE_UP: |
| 1924 | { |
| 1925 | png_uint_32 i; |
| 1926 | png_uint_32 istop = row_info->rowbytes; |
| 1927 | png_bytep rp = row; |
| 1928 | png_bytep pp = prev_row; |
| 1929 | |
| 1930 | for (i = 0; i < istop; i++) |
| 1931 | { |
| 1932 | *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); |
| 1933 | rp++; |
| 1934 | } |
| 1935 | break; |
| 1936 | } |
| 1937 | case PNG_FILTER_VALUE_AVG: |
| 1938 | { |
| 1939 | png_uint_32 i; |
| 1940 | png_bytep rp = row; |
| 1941 | png_bytep pp = prev_row; |
| 1942 | png_bytep lp = row; |
| 1943 | png_uint_32 bpp = (row_info->pixel_depth + 7) / 8; |
| 1944 | png_uint_32 istop = row_info->rowbytes - bpp; |
| 1945 | |
| 1946 | for (i = 0; i < bpp; i++) |
| 1947 | { |
| 1948 | *rp = (png_byte)(((int)(*rp) + |
| 1949 | ((int)(*pp++) / 2)) & 0xff); |
| 1950 | rp++; |
| 1951 | } |
| 1952 | |
| 1953 | for (i = 0; i < istop; i++) |
| 1954 | { |
| 1955 | *rp = (png_byte)(((int)(*rp) + |
| 1956 | (int)(*pp++ + *lp++) / 2) & 0xff); |
| 1957 | rp++; |
| 1958 | } |
| 1959 | break; |
| 1960 | } |
| 1961 | case PNG_FILTER_VALUE_PAETH: |
| 1962 | { |
| 1963 | png_uint_32 i; |
| 1964 | png_bytep rp = row; |
| 1965 | png_bytep pp = prev_row; |
| 1966 | png_bytep lp = row; |
| 1967 | png_bytep cp = prev_row; |
| 1968 | png_uint_32 bpp = (row_info->pixel_depth + 7) / 8; |
| 1969 | png_uint_32 istop=row_info->rowbytes - bpp; |
| 1970 | |
| 1971 | for (i = 0; i < bpp; i++) |
| 1972 | { |
| 1973 | *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); |
| 1974 | rp++; |
| 1975 | } |
| 1976 | |
| 1977 | for (i = 0; i < istop; i++) /* use leftover rp,pp */ |
| 1978 | { |
| 1979 | int a, b, c, pa, pb, pc, p; |
| 1980 | |
| 1981 | a = *lp++; |
| 1982 | b = *pp++; |
| 1983 | c = *cp++; |
| 1984 | |
| 1985 | p = b - c; |
| 1986 | pc = a - c; |
| 1987 | |
| 1988 | #ifdef PNG_USE_ABS |
| 1989 | pa = abs(p); |
| 1990 | pb = abs(pc); |
| 1991 | pc = abs(p + pc); |
| 1992 | #else |
| 1993 | pa = p < 0 ? -p : p; |
| 1994 | pb = pc < 0 ? -pc : pc; |
| 1995 | pc = (p + pc) < 0 ? -(p + pc) : p + pc; |
| 1996 | #endif |
| 1997 | |
| 1998 | /* |
| 1999 | if (pa <= pb && pa <= pc) |
| 2000 | p = a; |
| 2001 | else if (pb <= pc) |
| 2002 | p = b; |
| 2003 | else |
| 2004 | p = c; |
| 2005 | */ |
| 2006 | |
| 2007 | p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; |
| 2008 | |
| 2009 | *rp = (png_byte)(((int)(*rp) + p) & 0xff); |
| 2010 | rp++; |
| 2011 | } |
| 2012 | break; |
| 2013 | } |
| 2014 | default: |
| 2015 | png_warning(png_ptr, "Ignoring bad adaptive filter type"); |
| 2016 | *row=0; |
| 2017 | break; |
| 2018 | } |
| 2019 | } |
| 2020 | |
| 2021 | void |
| 2022 | png_read_finish_row(png_structp png_ptr) |
| 2023 | { |
| 2024 | png_debug(1, "in png_read_finish_row\n"); |
| 2025 | png_ptr->row_number++; |
| 2026 | if (png_ptr->row_number < png_ptr->num_rows) |
| 2027 | return; |
| 2028 | |
| 2029 | if (png_ptr->interlaced) |
| 2030 | { |
| 2031 | png_ptr->row_number = 0; |
| 2032 | png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1); |
| 2033 | do |
| 2034 | { |
| 2035 | png_ptr->pass++; |
| 2036 | if (png_ptr->pass >= 7) |
| 2037 | break; |
| 2038 | png_ptr->iwidth = (png_ptr->width + |
| 2039 | png_pass_inc[png_ptr->pass] - 1 - |
| 2040 | png_pass_start[png_ptr->pass]) / |
| 2041 | png_pass_inc[png_ptr->pass]; |
| 2042 | png_ptr->irowbytes = ((png_ptr->iwidth * |
| 2043 | (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1; |
| 2044 | |
| 2045 | if (!(png_ptr->transformations & PNG_INTERLACE)) |
| 2046 | { |
| 2047 | png_ptr->num_rows = (png_ptr->height + |
| 2048 | png_pass_yinc[png_ptr->pass] - 1 - |
| 2049 | png_pass_ystart[png_ptr->pass]) / |
| 2050 | png_pass_yinc[png_ptr->pass]; |
| 2051 | if (!(png_ptr->num_rows)) |
| 2052 | continue; |
| 2053 | } |
| 2054 | else /* if (png_ptr->transformations & PNG_INTERLACE) */ |
| 2055 | break; |
| 2056 | } while (png_ptr->iwidth == 0); |
| 2057 | |
| 2058 | if (png_ptr->pass < 7) |
| 2059 | return; |
| 2060 | } |
| 2061 | |
| 2062 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) |
| 2063 | { |
| 2064 | char extra; |
| 2065 | int ret; |
| 2066 | |
| 2067 | png_ptr->zstream.next_out = (Byte *)&extra; |
| 2068 | png_ptr->zstream.avail_out = (uInt)1; |
| 2069 | for(;;) |
| 2070 | { |
| 2071 | if (!(png_ptr->zstream.avail_in)) |
| 2072 | { |
| 2073 | while (!png_ptr->idat_size) |
| 2074 | { |
| 2075 | png_byte chunk_length[4]; |
| 2076 | |
| 2077 | png_crc_finish(png_ptr, 0); |
| 2078 | |
| 2079 | png_read_data(png_ptr, chunk_length, 4); |
| 2080 | png_ptr->idat_size = png_get_uint_32(chunk_length); |
| 2081 | |
| 2082 | png_reset_crc(png_ptr); |
| 2083 | png_crc_read(png_ptr, png_ptr->chunk_name, 4); |
| 2084 | if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
| 2085 | png_error(png_ptr, "Not enough image data"); |
| 2086 | |
| 2087 | } |
| 2088 | png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; |
| 2089 | png_ptr->zstream.next_in = png_ptr->zbuf; |
| 2090 | if (png_ptr->zbuf_size > png_ptr->idat_size) |
| 2091 | png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; |
| 2092 | png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in); |
| 2093 | png_ptr->idat_size -= png_ptr->zstream.avail_in; |
| 2094 | } |
| 2095 | ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); |
| 2096 | if (ret == Z_STREAM_END) |
| 2097 | { |
| 2098 | if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in || |
| 2099 | png_ptr->idat_size) |
| 2100 | png_error(png_ptr, "Extra compressed data"); |
| 2101 | png_ptr->mode |= PNG_AFTER_IDAT; |
| 2102 | png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; |
| 2103 | break; |
| 2104 | } |
| 2105 | if (ret != Z_OK) |
| 2106 | png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : |
| 2107 | "Decompression Error"); |
| 2108 | |
| 2109 | if (!(png_ptr->zstream.avail_out)) |
| 2110 | png_error(png_ptr, "Extra compressed data"); |
| 2111 | |
| 2112 | } |
| 2113 | png_ptr->zstream.avail_out = 0; |
| 2114 | } |
| 2115 | |
| 2116 | if (png_ptr->idat_size || png_ptr->zstream.avail_in) |
| 2117 | png_error(png_ptr, "Extra compression data"); |
| 2118 | |
| 2119 | inflateReset(&png_ptr->zstream); |
| 2120 | |
| 2121 | png_ptr->mode |= PNG_AFTER_IDAT; |
| 2122 | } |
| 2123 | |
| 2124 | void |
| 2125 | png_read_start_row(png_structp png_ptr) |
| 2126 | { |
| 2127 | int max_pixel_depth; |
| 2128 | png_uint_32 row_bytes; |
| 2129 | |
| 2130 | png_debug(1, "in png_read_start_row\n"); |
| 2131 | png_ptr->zstream.avail_in = 0; |
| 2132 | png_init_read_transformations(png_ptr); |
| 2133 | if (png_ptr->interlaced) |
| 2134 | { |
| 2135 | if (!(png_ptr->transformations & PNG_INTERLACE)) |
| 2136 | png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - |
| 2137 | png_pass_ystart[0]) / png_pass_yinc[0]; |
| 2138 | else |
| 2139 | png_ptr->num_rows = png_ptr->height; |
| 2140 | |
| 2141 | png_ptr->iwidth = (png_ptr->width + |
| 2142 | png_pass_inc[png_ptr->pass] - 1 - |
| 2143 | png_pass_start[png_ptr->pass]) / |
| 2144 | png_pass_inc[png_ptr->pass]; |
| 2145 | |
| 2146 | row_bytes = ((png_ptr->iwidth * |
| 2147 | (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1; |
| 2148 | png_ptr->irowbytes = (png_size_t)row_bytes; |
| 2149 | if((png_uint_32)png_ptr->irowbytes != row_bytes) |
| 2150 | png_error(png_ptr, "Rowbytes overflow in png_read_start_row"); |
| 2151 | } |
| 2152 | else |
| 2153 | { |
| 2154 | png_ptr->num_rows = png_ptr->height; |
| 2155 | png_ptr->iwidth = png_ptr->width; |
| 2156 | png_ptr->irowbytes = png_ptr->rowbytes + 1; |
| 2157 | } |
| 2158 | max_pixel_depth = png_ptr->pixel_depth; |
| 2159 | |
| 2160 | #if defined(PNG_READ_PACK_SUPPORTED) |
| 2161 | if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) |
| 2162 | max_pixel_depth = 8; |
| 2163 | #endif |
| 2164 | |
| 2165 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
| 2166 | if (png_ptr->transformations & PNG_EXPAND) |
| 2167 | { |
| 2168 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 2169 | { |
| 2170 | if (png_ptr->num_trans) |
| 2171 | max_pixel_depth = 32; |
| 2172 | else |
| 2173 | max_pixel_depth = 24; |
| 2174 | } |
| 2175 | else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) |
| 2176 | { |
| 2177 | if (max_pixel_depth < 8) |
| 2178 | max_pixel_depth = 8; |
| 2179 | if (png_ptr->num_trans) |
| 2180 | max_pixel_depth *= 2; |
| 2181 | } |
| 2182 | else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) |
| 2183 | { |
| 2184 | if (png_ptr->num_trans) |
| 2185 | { |
| 2186 | max_pixel_depth *= 4; |
| 2187 | max_pixel_depth /= 3; |
| 2188 | } |
| 2189 | } |
| 2190 | } |
| 2191 | #endif |
| 2192 | |
| 2193 | #if defined(PNG_READ_FILLER_SUPPORTED) |
| 2194 | if (png_ptr->transformations & (PNG_FILLER)) |
| 2195 | { |
| 2196 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 2197 | max_pixel_depth = 32; |
| 2198 | else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) |
| 2199 | { |
| 2200 | if (max_pixel_depth <= 8) |
| 2201 | max_pixel_depth = 16; |
| 2202 | else |
| 2203 | max_pixel_depth = 32; |
| 2204 | } |
| 2205 | else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) |
| 2206 | { |
| 2207 | if (max_pixel_depth <= 32) |
| 2208 | max_pixel_depth = 32; |
| 2209 | else |
| 2210 | max_pixel_depth = 64; |
| 2211 | } |
| 2212 | } |
| 2213 | #endif |
| 2214 | |
| 2215 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
| 2216 | if (png_ptr->transformations & PNG_GRAY_TO_RGB) |
| 2217 | { |
| 2218 | if ( |
| 2219 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
| 2220 | (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) || |
| 2221 | #endif |
| 2222 | #if defined(PNG_READ_FILLER_SUPPORTED) |
| 2223 | (png_ptr->transformations & (PNG_FILLER)) || |
| 2224 | #endif |
| 2225 | png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
| 2226 | { |
| 2227 | if (max_pixel_depth <= 16) |
| 2228 | max_pixel_depth = 32; |
| 2229 | else |
| 2230 | max_pixel_depth = 64; |
| 2231 | } |
| 2232 | else |
| 2233 | { |
| 2234 | if (max_pixel_depth <= 8) |
| 2235 | max_pixel_depth = 24; |
| 2236 | else |
| 2237 | max_pixel_depth = 48; |
| 2238 | } |
| 2239 | } |
| 2240 | #endif |
| 2241 | |
| 2242 | /* align the width on the next larger 8 pixels. Mainly used |
| 2243 | for interlacing */ |
| 2244 | row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); |
| 2245 | /* calculate the maximum bytes needed, adding a byte and a pixel |
| 2246 | for safety's sake */ |
| 2247 | row_bytes = ((row_bytes * (png_uint_32)max_pixel_depth + 7) >> 3) + |
| 2248 | 1 + ((max_pixel_depth + 7) >> 3); |
| 2249 | #ifdef PNG_MAX_MALLOC_64K |
| 2250 | if (row_bytes > (png_uint_32)65536L) |
| 2251 | png_error(png_ptr, "This image requires a row greater than 64KB"); |
| 2252 | #endif |
| 2253 | png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, row_bytes); |
| 2254 | |
| 2255 | #ifdef PNG_MAX_MALLOC_64K |
| 2256 | if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L) |
| 2257 | png_error(png_ptr, "This image requires a row greater than 64KB"); |
| 2258 | #endif |
| 2259 | png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)( |
| 2260 | png_ptr->rowbytes + 1)); |
| 2261 | |
| 2262 | png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1); |
| 2263 | |
| 2264 | png_debug1(3, "width = %d,\n", png_ptr->width); |
| 2265 | png_debug1(3, "height = %d,\n", png_ptr->height); |
| 2266 | png_debug1(3, "iwidth = %d,\n", png_ptr->iwidth); |
| 2267 | png_debug1(3, "num_rows = %d\n", png_ptr->num_rows); |
| 2268 | png_debug1(3, "rowbytes = %d,\n", png_ptr->rowbytes); |
| 2269 | png_debug1(3, "irowbytes = %d,\n", png_ptr->irowbytes); |
| 2270 | |
| 2271 | png_ptr->flags |= PNG_FLAG_ROW_INIT; |
| 2272 | } |