Sireesh Tripurari | b478e66 | 2014-05-09 15:15:10 +0530 | [diff] [blame] | 1 | /* pngimage.c |
| 2 | * |
| 3 | * Copyright (c) 2014 John Cunningham Bowler |
| 4 | * |
| 5 | * Last changed in libpng 1.6.10 [March 6, 2014] |
| 6 | * |
| 7 | * This code is released under the libpng license. |
| 8 | * For conditions of distribution and use, see the disclaimer |
| 9 | * and license in png.h |
| 10 | * |
| 11 | * Test the png_read_png and png_write_png interfaces. Given a PNG file load it |
| 12 | * using png_read_png and then write with png_write_png. Test all possible |
| 13 | * transforms. |
| 14 | */ |
| 15 | #include <stdarg.h> |
| 16 | #include <stdlib.h> |
| 17 | #include <string.h> |
| 18 | #include <errno.h> |
| 19 | #include <stdio.h> |
| 20 | #include <assert.h> |
| 21 | |
| 22 | #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) |
| 23 | # include <config.h> |
| 24 | #endif |
| 25 | |
| 26 | /* Define the following to use this test against your installed libpng, rather |
| 27 | * than the one being built here: |
| 28 | */ |
| 29 | #ifdef PNG_FREESTANDING_TESTS |
| 30 | # include <png.h> |
| 31 | #else |
| 32 | # include "../../png.h" |
| 33 | #endif |
| 34 | |
| 35 | #ifndef PNG_SETJMP_SUPPORTED |
| 36 | # include <setjmp.h> /* because png.h did *not* include this */ |
| 37 | #endif |
| 38 | |
| 39 | #if defined(PNG_INFO_IMAGE_SUPPORTED) && defined(PNG_SEQUENTIAL_READ_SUPPORTED) |
| 40 | /* If a transform is valid on both read and write this implies that if the |
| 41 | * transform is applied to read it must also be applied on write to produce |
| 42 | * meaningful data. This is because these transforms when performed on read |
| 43 | * produce data with a memory format that does not correspond to a PNG format. |
| 44 | * |
| 45 | * Most of these transforms are invertible; after applying the transform on |
| 46 | * write the result is the original PNG data that would have would have been |
| 47 | * read if no transform were applied. |
| 48 | * |
| 49 | * The exception is _SHIFT, which destroys the low order bits marked as not |
| 50 | * significant in a PNG with the sBIT chunk. |
| 51 | * |
| 52 | * The following table lists, for each transform, the conditions under which it |
| 53 | * is expected to do anything. Conditions are defined as follows: |
| 54 | * |
| 55 | * 1) Color mask bits required - simply a mask to AND with color_type; one of |
| 56 | * these must be present for the transform to fire, except that 0 means |
| 57 | * 'always'. |
| 58 | * 2) Color mask bits which must be absent - another mask - none of these must |
| 59 | * be present. |
| 60 | * 3) Bit depths - a mask of component bit depths for the transform to fire. |
| 61 | * 4) 'read' - the transform works in png_read_png. |
| 62 | * 5) 'write' - the transform works in png_write_png. |
| 63 | * 6) PNG_INFO_chunk; a mask of the chunks that must be present for the |
| 64 | * transform to fire. All must be present - the requirement is that |
| 65 | * png_get_valid() & mask == mask, so if mask is 0 there is no requirement. |
| 66 | * |
| 67 | * The condition refers to the original image state - if multiple transforms are |
| 68 | * used together it is possible to cause a transform that wouldn't fire on the |
| 69 | * original image to fire. |
| 70 | */ |
| 71 | static struct transform_info |
| 72 | { |
| 73 | const char *name; |
| 74 | int transform; |
| 75 | png_uint_32 valid_chunks; |
| 76 | # define CHUNK_NONE 0 |
| 77 | # define CHUNK_sBIT PNG_INFO_sBIT |
| 78 | # define CHUNK_tRNS PNG_INFO_tRNS |
| 79 | png_byte color_mask_required; |
| 80 | png_byte color_mask_absent; |
| 81 | # define COLOR_MASK_X 0 |
| 82 | # define COLOR_MASK_P PNG_COLOR_MASK_PALETTE |
| 83 | # define COLOR_MASK_C PNG_COLOR_MASK_COLOR |
| 84 | # define COLOR_MASK_A PNG_COLOR_MASK_ALPHA |
| 85 | # define COLOR_MASK_ALL (PALETTE+COLOR+ALPHA) /* absent = gray, no alpha */ |
| 86 | png_byte bit_depths; |
| 87 | # define BD_ALL (1 + 2 + 4 + 8 + 16) |
| 88 | # define BD_PAL (1 + 2 + 4 + 8) |
| 89 | # define BD_LOW (1 + 2 + 4) |
| 90 | # define BD_16 16 |
| 91 | # define BD_TRUE (8+16) /* i.e. true-color depths */ |
| 92 | png_byte when; |
| 93 | # define TRANSFORM_R 1 |
| 94 | # define TRANSFORM_W 2 |
| 95 | # define TRANSFORM_RW 3 |
| 96 | png_byte tested; /* the transform was tested somewhere */ |
| 97 | } transform_info[] = |
| 98 | { |
| 99 | /* List ALL the PNG_TRANSFORM_ macros here. Check for support using the READ |
| 100 | * macros; even if the transform is supported on write it cannot be tested |
| 101 | * without the read support. |
| 102 | */ |
| 103 | # define T(name,chunk,cm_required,cm_absent,bd,when)\ |
| 104 | { #name, PNG_TRANSFORM_ ## name, CHUNK_ ## chunk,\ |
| 105 | COLOR_MASK_ ## cm_required, COLOR_MASK_ ## cm_absent, BD_ ## bd,\ |
| 106 | TRANSFORM_ ## when, 0/*!tested*/ } |
| 107 | |
| 108 | #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
| 109 | T(STRIP_16, NONE, X, X, 16, R), |
| 110 | /* drops the bottom 8 bits when bit depth is 16 */ |
| 111 | #endif |
| 112 | #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
| 113 | T(STRIP_ALPHA, NONE, A, X, ALL, R), |
| 114 | /* removes the alpha channel if present */ |
| 115 | #endif |
| 116 | #ifdef PNG_WRITE_PACK_SUPPORTED |
| 117 | # define TRANSFORM_RW_PACK TRANSFORM_RW |
| 118 | #else |
| 119 | # define TRANSFORM_RW_PACK TRANSFORM_R |
| 120 | #endif |
| 121 | #ifdef PNG_READ_PACK_SUPPORTED |
| 122 | T(PACKING, NONE, X, X, LOW, RW_PACK), |
| 123 | /* unpacks low-bit-depth components into 1 byte per component on read, |
| 124 | * reverses this on write. |
| 125 | */ |
| 126 | #endif |
| 127 | #ifdef PNG_WRITE_PACKSWAP_SUPPORTED |
| 128 | # define TRANSFORM_RW_PACKSWAP TRANSFORM_RW |
| 129 | #else |
| 130 | # define TRANSFORM_RW_PACKSWAP TRANSFORM_R |
| 131 | #endif |
| 132 | #ifdef PNG_READ_PACKSWAP_SUPPORTED |
| 133 | T(PACKSWAP, NONE, X, X, LOW, RW_PACKSWAP), |
| 134 | /* reverses the order of low-bit-depth components packed into a byte */ |
| 135 | #endif |
| 136 | #ifdef PNG_READ_EXPAND_SUPPORTED |
| 137 | T(EXPAND, NONE, P, X, ALL, R), |
| 138 | /* expands PLTE PNG files to RGB (no tRNS) or RGBA (tRNS) * |
| 139 | * Note that the 'EXPAND' transform does lots of different things: */ |
| 140 | T(EXPAND, NONE, X, C, ALL, R), |
| 141 | /* expands grayscale PNG files to RGB, or RGBA */ |
| 142 | T(EXPAND, tRNS, X, A, ALL, R), |
| 143 | /* expands the tRNS chunk in files without alpha */ |
| 144 | #endif |
| 145 | #ifdef PNG_WRITE_INVERT_SUPPORTED |
| 146 | # define TRANSFORM_RW_INVERT TRANSFORM_RW |
| 147 | #else |
| 148 | # define TRANSFORM_RW_INVERT TRANSFORM_R |
| 149 | #endif |
| 150 | #ifdef PNG_READ_INVERT_SUPPORTED |
| 151 | T(INVERT_MONO, NONE, X, C, ALL, RW_INVERT), |
| 152 | /* converts gray-scale components to 1..0 from 0..1 */ |
| 153 | #endif |
| 154 | #ifdef PNG_WRITE_SHIFT_SUPPORTED |
| 155 | # define TRANSFORM_RW_SHIFT TRANSFORM_RW |
| 156 | #else |
| 157 | # define TRANSFORM_RW_SHIFT TRANSFORM_R |
| 158 | #endif |
| 159 | #ifdef PNG_READ_SHIFT_SUPPORTED |
| 160 | T(SHIFT, sBIT, X, X, ALL, RW_SHIFT), |
| 161 | /* reduces component values to the original range based on the sBIT chunk, |
| 162 | * this is only partially reversible - the low bits are lost and cannot be |
| 163 | * recovered on write. In fact write code replicates the bits to generate |
| 164 | * new low-order bits. |
| 165 | */ |
| 166 | #endif |
| 167 | #ifdef PNG_WRITE_BGR_SUPPORTED |
| 168 | # define TRANSFORM_RW_BGR TRANSFORM_RW |
| 169 | #else |
| 170 | # define TRANSFORM_RW_BGR TRANSFORM_R |
| 171 | #endif |
| 172 | #ifdef PNG_READ_BGR_SUPPORTED |
| 173 | T(BGR, NONE, C, P, TRUE, RW_BGR), |
| 174 | /* reverses the rgb component values of true-color pixels */ |
| 175 | #endif |
| 176 | #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED |
| 177 | # define TRANSFORM_RW_SWAP_ALPHA TRANSFORM_RW |
| 178 | #else |
| 179 | # define TRANSFORM_RW_SWAP_ALPHA TRANSFORM_R |
| 180 | #endif |
| 181 | #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED |
| 182 | T(SWAP_ALPHA, NONE, A, X, TRUE, RW_SWAP_ALPHA), |
| 183 | /* swaps the alpha channel of RGBA or GA pixels to the front - ARGB or |
| 184 | * AG, on write reverses the process. |
| 185 | */ |
| 186 | #endif |
| 187 | #ifdef PNG_WRITE_SWAP_SUPPORTED |
| 188 | # define TRANSFORM_RW_SWAP TRANSFORM_RW |
| 189 | #else |
| 190 | # define TRANSFORM_RW_SWAP TRANSFORM_R |
| 191 | #endif |
| 192 | #ifdef PNG_READ_SWAP_SUPPORTED |
| 193 | T(SWAP_ENDIAN, NONE, X, P, 16, RW_SWAP), |
| 194 | /* byte-swaps 16-bit component values */ |
| 195 | #endif |
| 196 | #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED |
| 197 | # define TRANSFORM_RW_INVERT_ALPHA TRANSFORM_RW |
| 198 | #else |
| 199 | # define TRANSFORM_RW_INVERT_ALPHA TRANSFORM_R |
| 200 | #endif |
| 201 | #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED |
| 202 | T(INVERT_ALPHA, NONE, A, X, TRUE, RW_INVERT_ALPHA), |
| 203 | /* converts an alpha channel from 0..1 to 1..0 */ |
| 204 | #endif |
| 205 | #ifdef PNG_WRITE_FILLER_SUPPORTED |
| 206 | T(STRIP_FILLER_BEFORE, NONE, A, P, TRUE, W), /* 'A' for a filler! */ |
| 207 | /* on write skips a leading filler channel; testing requires data with a |
| 208 | * filler channel so this is produced from RGBA or GA images by removing |
| 209 | * the 'alpha' flag from the color type in place. |
| 210 | */ |
| 211 | T(STRIP_FILLER_AFTER, NONE, A, P, TRUE, W), |
| 212 | /* on write strips a trailing filler channel */ |
| 213 | #endif |
| 214 | #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
| 215 | T(GRAY_TO_RGB, NONE, X, C, ALL, R), |
| 216 | /* expands grayscale images to RGB, also causes the palette part of |
| 217 | * 'EXPAND' to happen. Low bit depth grayscale images are expanded to |
| 218 | * 8-bits per component and no attempt is made to convert the image to a |
| 219 | * palette image. While this transform is partially reversible |
| 220 | * png_write_png does not currently support this. |
| 221 | */ |
| 222 | T(GRAY_TO_RGB, NONE, P, X, ALL, R), |
| 223 | /* The 'palette' side effect mentioned above; a bit bogus but this is the |
| 224 | * way the libpng code works. |
| 225 | */ |
| 226 | #endif |
| 227 | #ifdef PNG_READ_EXPAND_16_SUPPORTED |
| 228 | T(EXPAND_16, NONE, X, X, PAL, R), |
| 229 | /* expands images to 16-bits per component, as a side effect expands |
| 230 | * palette images to RGB and expands the tRNS chunk if present, so it can |
| 231 | * modify 16-bit per component images as well: |
| 232 | */ |
| 233 | T(EXPAND_16, tRNS, X, A, 16, R), |
| 234 | /* side effect of EXPAND_16 - expands the tRNS chunk in an RGB or G 16-bit |
| 235 | * image. |
| 236 | */ |
| 237 | #endif |
| 238 | #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
| 239 | T(SCALE_16, NONE, X, X, 16, R) |
| 240 | /* scales 16-bit components to 8-bits. */ |
| 241 | #endif |
| 242 | |
| 243 | #undef T |
| 244 | }; |
| 245 | |
| 246 | #define ARRAY_SIZE(a) ((sizeof a)/(sizeof a[0])) |
| 247 | #define TTABLE_SIZE ARRAY_SIZE(transform_info) |
| 248 | |
| 249 | /* Some combinations of options that should be reversible are not; these cases |
| 250 | * are bugs. |
| 251 | */ |
| 252 | static int known_bad_combos[][2] = |
| 253 | { |
| 254 | /* problem, antidote */ |
| 255 | { PNG_TRANSFORM_SHIFT | PNG_TRANSFORM_INVERT_ALPHA, 0/*antidote*/ } |
| 256 | }; |
| 257 | |
| 258 | static int |
| 259 | is_combo(int transforms) |
| 260 | { |
| 261 | return transforms & (transforms-1); /* non-zero if more than one set bit */ |
| 262 | } |
| 263 | |
| 264 | static int |
| 265 | first_transform(int transforms) |
| 266 | { |
| 267 | return transforms & -transforms; /* lowest set bit */ |
| 268 | } |
| 269 | |
| 270 | static int |
| 271 | is_bad_combo(int transforms) |
| 272 | { |
| 273 | unsigned int i; |
| 274 | |
| 275 | for (i=0; i<ARRAY_SIZE(known_bad_combos); ++i) |
| 276 | { |
| 277 | int combo = known_bad_combos[i][0]; |
| 278 | |
| 279 | if ((combo & transforms) == combo && |
| 280 | (transforms & known_bad_combos[i][1]) == 0) |
| 281 | return 1; |
| 282 | } |
| 283 | |
| 284 | return 0; /* combo is ok */ |
| 285 | } |
| 286 | |
| 287 | static const char * |
| 288 | transform_name(int t) |
| 289 | /* The name, if 't' has multiple bits set the name of the lowest set bit is |
| 290 | * returned. |
| 291 | */ |
| 292 | { |
| 293 | unsigned int i; |
| 294 | |
| 295 | t &= -t; /* first set bit */ |
| 296 | |
| 297 | for (i=0; i<TTABLE_SIZE; ++i) |
| 298 | { |
| 299 | if ((transform_info[i].transform & t) != 0) |
| 300 | return transform_info[i].name; |
| 301 | } |
| 302 | |
| 303 | return "invalid transform"; |
| 304 | } |
| 305 | |
| 306 | /* Variables calculated by validate_T below and used to record all the supported |
| 307 | * transforms. Need (unsigned int) here because of the places where these |
| 308 | * values are used (unsigned compares in the 'exhaustive' iterator.) |
| 309 | */ |
| 310 | static unsigned int read_transforms, write_transforms, rw_transforms; |
| 311 | |
| 312 | static void |
| 313 | validate_T(void) |
| 314 | /* Validate the above table - this just builds the above values */ |
| 315 | { |
| 316 | unsigned int i; |
| 317 | |
| 318 | for (i=0; i<TTABLE_SIZE; ++i) |
| 319 | { |
| 320 | if (transform_info[i].when & TRANSFORM_R) |
| 321 | read_transforms |= transform_info[i].transform; |
| 322 | |
| 323 | if (transform_info[i].when & TRANSFORM_W) |
| 324 | write_transforms |= transform_info[i].transform; |
| 325 | } |
| 326 | |
| 327 | /* Reversible transforms are those which are supported on both read and |
| 328 | * write. |
| 329 | */ |
| 330 | rw_transforms = read_transforms & write_transforms; |
| 331 | } |
| 332 | |
| 333 | /* FILE DATA HANDLING |
| 334 | * The original file is cached in memory. During write the output file is |
| 335 | * written to memory. |
| 336 | * |
| 337 | * In both cases the file data is held in a linked list of buffers - not all |
| 338 | * of these are in use at any time. |
| 339 | */ |
| 340 | struct buffer_list |
| 341 | { |
| 342 | struct buffer_list *next; /* next buffer in list */ |
| 343 | png_byte buffer[1024]; /* the actual buffer */ |
| 344 | }; |
| 345 | |
| 346 | struct buffer |
| 347 | { |
| 348 | struct buffer_list *last; /* last buffer in use */ |
| 349 | size_t end_count; /* bytes in the last buffer */ |
| 350 | struct buffer_list *current; /* current buffer being read */ |
| 351 | size_t read_count; /* count of bytes read from current */ |
| 352 | struct buffer_list first; /* the very first buffer */ |
| 353 | }; |
| 354 | |
| 355 | static void |
| 356 | buffer_init(struct buffer *buffer) |
| 357 | /* Call this only once for a given buffer */ |
| 358 | { |
| 359 | buffer->first.next = NULL; |
| 360 | buffer->last = NULL; |
| 361 | buffer->current = NULL; |
| 362 | } |
| 363 | |
| 364 | #ifdef PNG_WRITE_SUPPORTED |
| 365 | static void |
| 366 | buffer_start_write(struct buffer *buffer) |
| 367 | { |
| 368 | buffer->last = &buffer->first; |
| 369 | buffer->end_count = 0; |
| 370 | buffer->current = NULL; |
| 371 | } |
| 372 | #endif |
| 373 | |
| 374 | static void |
| 375 | buffer_start_read(struct buffer *buffer) |
| 376 | { |
| 377 | buffer->current = &buffer->first; |
| 378 | buffer->read_count = 0; |
| 379 | } |
| 380 | |
| 381 | #ifdef ENOMEM /* required by POSIX 1003.1 */ |
| 382 | # define MEMORY ENOMEM |
| 383 | #else |
| 384 | # define MEMORY ERANGE /* required by ANSI-C */ |
| 385 | #endif |
| 386 | static struct buffer * |
| 387 | get_buffer(png_structp pp) |
| 388 | /* Used from libpng callbacks to get the current buffer */ |
| 389 | { |
| 390 | return (struct buffer*)png_get_io_ptr(pp); |
| 391 | } |
| 392 | |
| 393 | #define NEW(type) ((type *)malloc(sizeof (type))) |
| 394 | |
| 395 | static struct buffer_list * |
| 396 | buffer_extend(struct buffer_list *current) |
| 397 | { |
| 398 | struct buffer_list *add; |
| 399 | |
| 400 | assert(current->next == NULL); |
| 401 | |
| 402 | add = NEW(struct buffer_list); |
| 403 | if (add == NULL) |
| 404 | return NULL; |
| 405 | |
| 406 | add->next = NULL; |
| 407 | current->next = add; |
| 408 | |
| 409 | return add; |
| 410 | } |
| 411 | |
| 412 | /* Load a buffer from a file; does the equivalent of buffer_start_write. On a |
| 413 | * read error returns an errno value, else returns 0. |
| 414 | */ |
| 415 | static int |
| 416 | buffer_from_file(struct buffer *buffer, FILE *fp) |
| 417 | { |
| 418 | struct buffer_list *last = &buffer->first; |
| 419 | size_t count = 0; |
| 420 | |
| 421 | for (;;) |
| 422 | { |
| 423 | size_t r = fread(last->buffer+count, 1/*size*/, |
| 424 | (sizeof last->buffer)-count, fp); |
| 425 | |
| 426 | if (r > 0) |
| 427 | { |
| 428 | count += r; |
| 429 | |
| 430 | if (count >= sizeof last->buffer) |
| 431 | { |
| 432 | assert(count == sizeof last->buffer); |
| 433 | count = 0; |
| 434 | |
| 435 | if (last->next == NULL) |
| 436 | { |
| 437 | last = buffer_extend(last); |
| 438 | if (last == NULL) |
| 439 | return MEMORY; |
| 440 | } |
| 441 | |
| 442 | else |
| 443 | last = last->next; |
| 444 | } |
| 445 | } |
| 446 | |
| 447 | else /* fread failed - probably end of file */ |
| 448 | { |
| 449 | if (feof(fp)) |
| 450 | { |
| 451 | buffer->last = last; |
| 452 | buffer->end_count = count; |
| 453 | return 0; /* no error */ |
| 454 | } |
| 455 | |
| 456 | /* Some kind of funky error; errno should be non-zero */ |
| 457 | return errno == 0 ? ERANGE : errno; |
| 458 | } |
| 459 | } |
| 460 | } |
| 461 | |
| 462 | /* This structure is used to control the test of a single file. */ |
| 463 | typedef enum |
| 464 | { |
| 465 | VERBOSE, /* switches on all messages */ |
| 466 | INFORMATION, |
| 467 | WARNINGS, /* switches on warnings */ |
| 468 | LIBPNG_WARNING, |
| 469 | APP_WARNING, |
| 470 | ERRORS, /* just errors */ |
| 471 | APP_FAIL, /* continuable error - no need to longjmp */ |
| 472 | LIBPNG_ERROR, /* this and higher cause a longjmp */ |
| 473 | LIBPNG_BUG, /* erroneous behavior in libpng */ |
| 474 | APP_ERROR, /* such as out-of-memory in a callback */ |
| 475 | QUIET, /* no normal messages */ |
| 476 | USER_ERROR, /* such as file-not-found */ |
| 477 | INTERNAL_ERROR |
| 478 | } error_level; |
| 479 | #define LEVEL_MASK 0xf /* where the level is in 'options' */ |
| 480 | |
| 481 | #define EXHAUSTIVE 0x010 /* Test all combinations of active options */ |
| 482 | #define STRICT 0x020 /* Fail on warnings as well as errors */ |
| 483 | #define LOG 0x040 /* Log pass/fail to stdout */ |
| 484 | #define CONTINUE 0x080 /* Continue on APP_FAIL errors */ |
| 485 | #define SKIP_BUGS 0x100 /* Skip over known bugs */ |
| 486 | #define LOG_SKIPPED 0x200 /* Log skipped bugs */ |
| 487 | #define FIND_BAD_COMBOS 0x400 /* Attempt to deduce bad combos */ |
| 488 | |
| 489 | /* Result masks apply to the result bits in the 'results' field below; these |
| 490 | * bits are simple 1U<<error_level. A pass requires either nothing worse than |
| 491 | * warnings (--relaxes) or nothing worse than information (--strict) |
| 492 | */ |
| 493 | #define RESULT_STRICT(r) (((r) & ~((1U<<WARNINGS)-1)) == 0) |
| 494 | #define RESULT_RELAXED(r) (((r) & ~((1U<<ERRORS)-1)) == 0) |
| 495 | |
| 496 | struct display |
| 497 | { |
| 498 | jmp_buf error_return; /* Where to go to on error */ |
| 499 | |
| 500 | const char *filename; /* The name of the original file */ |
| 501 | const char *operation; /* Operation being performed */ |
| 502 | int transforms; /* Transform used in operation */ |
| 503 | png_uint_32 options; /* See display_log below */ |
| 504 | png_uint_32 results; /* A mask of errors seen */ |
| 505 | |
| 506 | |
| 507 | png_structp original_pp; /* used on the original read */ |
| 508 | png_infop original_ip; /* set by the original read */ |
| 509 | |
| 510 | png_size_t original_rowbytes; /* of the original rows: */ |
| 511 | png_bytepp original_rows; /* from the original read */ |
| 512 | |
| 513 | /* Original chunks valid */ |
| 514 | png_uint_32 chunks; |
| 515 | |
| 516 | /* Original IHDR information */ |
| 517 | png_uint_32 width; |
| 518 | png_uint_32 height; |
| 519 | int bit_depth; |
| 520 | int color_type; |
| 521 | int interlace_method; |
| 522 | int compression_method; |
| 523 | int filter_method; |
| 524 | |
| 525 | /* Derived information for the original image. */ |
| 526 | int active_transforms; /* transforms that do something on read */ |
| 527 | int ignored_transforms; /* transforms that should do nothing */ |
| 528 | |
| 529 | /* Used on a read, both the original read and when validating a written |
| 530 | * image. |
| 531 | */ |
| 532 | png_structp read_pp; |
| 533 | png_infop read_ip; |
| 534 | |
| 535 | # ifdef PNG_WRITE_SUPPORTED |
| 536 | /* Used to write a new image (the original info_ptr is used) */ |
| 537 | png_structp write_pp; |
| 538 | struct buffer written_file; /* where the file gets written */ |
| 539 | # endif |
| 540 | |
| 541 | struct buffer original_file; /* Data read from the original file */ |
| 542 | }; |
| 543 | |
| 544 | static void |
| 545 | display_init(struct display *dp) |
| 546 | /* Call this only once right at the start to initialize the control |
| 547 | * structure, the (struct buffer) lists are maintained across calls - the |
| 548 | * memory is not freed. |
| 549 | */ |
| 550 | { |
| 551 | memset(dp, 0, sizeof *dp); |
| 552 | dp->options = WARNINGS; /* default to !verbose, !quiet */ |
| 553 | dp->filename = NULL; |
| 554 | dp->operation = NULL; |
| 555 | dp->original_pp = NULL; |
| 556 | dp->original_ip = NULL; |
| 557 | dp->original_rows = NULL; |
| 558 | dp->read_pp = NULL; |
| 559 | dp->read_ip = NULL; |
| 560 | buffer_init(&dp->original_file); |
| 561 | |
| 562 | # ifdef PNG_WRITE_SUPPORTED |
| 563 | dp->write_pp = NULL; |
| 564 | buffer_init(&dp->written_file); |
| 565 | # endif |
| 566 | } |
| 567 | |
| 568 | static void |
| 569 | display_clean_read(struct display *dp) |
| 570 | { |
| 571 | if (dp->read_pp != NULL) |
| 572 | png_destroy_read_struct(&dp->read_pp, &dp->read_ip, NULL); |
| 573 | } |
| 574 | |
| 575 | #ifdef PNG_WRITE_SUPPORTED |
| 576 | static void |
| 577 | display_clean_write(struct display *dp) |
| 578 | { |
| 579 | if (dp->write_pp != NULL) |
| 580 | png_destroy_write_struct(&dp->write_pp, NULL); |
| 581 | } |
| 582 | #endif |
| 583 | |
| 584 | static void |
| 585 | display_clean(struct display *dp) |
| 586 | { |
| 587 | # ifdef PNG_WRITE_SUPPORTED |
| 588 | display_clean_write(dp); |
| 589 | # endif |
| 590 | display_clean_read(dp); |
| 591 | |
| 592 | dp->original_rowbytes = 0; |
| 593 | dp->original_rows = NULL; |
| 594 | dp->chunks = 0; |
| 595 | |
| 596 | png_destroy_read_struct(&dp->original_pp, &dp->original_ip, NULL); |
| 597 | /* leave the filename for error detection */ |
| 598 | dp->results = 0; /* reset for next time */ |
| 599 | } |
| 600 | |
| 601 | static struct display * |
| 602 | get_dp(png_structp pp) |
| 603 | /* The display pointer is always stored in the png_struct error pointer */ |
| 604 | { |
| 605 | struct display *dp = (struct display*)png_get_error_ptr(pp); |
| 606 | |
| 607 | if (dp == NULL) |
| 608 | { |
| 609 | fprintf(stderr, "pngimage: internal error (no display)\n"); |
| 610 | exit(99); /* prevents a crash */ |
| 611 | } |
| 612 | |
| 613 | return dp; |
| 614 | } |
| 615 | |
| 616 | /* error handling */ |
| 617 | #ifdef __GNUC__ |
| 618 | # define VGATTR __attribute__((__format__ (__printf__,3,4))) |
| 619 | /* Required to quiet GNUC warnings when the compiler sees a stdarg function |
| 620 | * that calls one of the stdio v APIs. |
| 621 | */ |
| 622 | #else |
| 623 | # define VGATTR |
| 624 | #endif |
| 625 | static void VGATTR |
| 626 | display_log(struct display *dp, error_level level, const char *fmt, ...) |
| 627 | /* 'level' is as above, fmt is a stdio style format string. This routine |
| 628 | * does not return if level is above LIBPNG_WARNING |
| 629 | */ |
| 630 | { |
| 631 | dp->results |= 1U << level; |
| 632 | |
| 633 | if (level > (error_level)(dp->options & LEVEL_MASK)) |
| 634 | { |
| 635 | const char *lp; |
| 636 | va_list ap; |
| 637 | |
| 638 | switch (level) |
| 639 | { |
| 640 | case INFORMATION: lp = "information"; break; |
| 641 | case LIBPNG_WARNING: lp = "warning(libpng)"; break; |
| 642 | case APP_WARNING: lp = "warning(pngimage)"; break; |
| 643 | case APP_FAIL: lp = "error(continuable)"; break; |
| 644 | case LIBPNG_ERROR: lp = "error(libpng)"; break; |
| 645 | case LIBPNG_BUG: lp = "bug(libpng)"; break; |
| 646 | case APP_ERROR: lp = "error(pngimage)"; break; |
| 647 | case USER_ERROR: lp = "error(user)"; break; |
| 648 | |
| 649 | case INTERNAL_ERROR: /* anything unexpected is an internal error: */ |
| 650 | case VERBOSE: case WARNINGS: case ERRORS: case QUIET: |
| 651 | default: lp = "bug(pngimage)"; break; |
| 652 | } |
| 653 | |
| 654 | fprintf(stderr, "%s: %s: %s", |
| 655 | dp->filename != NULL ? dp->filename : "<stdin>", lp, dp->operation); |
| 656 | |
| 657 | if (dp->transforms != 0) |
| 658 | { |
| 659 | int tr = dp->transforms; |
| 660 | |
| 661 | if (is_combo(tr)) |
| 662 | fprintf(stderr, "(0x%x)", tr); |
| 663 | |
| 664 | else |
| 665 | fprintf(stderr, "(%s)", transform_name(tr)); |
| 666 | } |
| 667 | |
| 668 | fprintf(stderr, ": "); |
| 669 | |
| 670 | va_start(ap, fmt); |
| 671 | vfprintf(stderr, fmt, ap); |
| 672 | va_end(ap); |
| 673 | |
| 674 | fputc('\n', stderr); |
| 675 | } |
| 676 | /* else do not output any message */ |
| 677 | |
| 678 | /* Errors cause this routine to exit to the fail code */ |
| 679 | if (level > APP_FAIL || (level > ERRORS && !(dp->options & CONTINUE))) |
| 680 | longjmp(dp->error_return, level); |
| 681 | } |
| 682 | |
| 683 | /* error handler callbacks for libpng */ |
| 684 | static void PNGCBAPI |
| 685 | display_warning(png_structp pp, png_const_charp warning) |
| 686 | { |
| 687 | display_log(get_dp(pp), LIBPNG_WARNING, "%s", warning); |
| 688 | } |
| 689 | |
| 690 | static void PNGCBAPI |
| 691 | display_error(png_structp pp, png_const_charp error) |
| 692 | { |
| 693 | struct display *dp = get_dp(pp); |
| 694 | |
| 695 | display_log(dp, LIBPNG_ERROR, "%s", error); |
| 696 | } |
| 697 | |
| 698 | static void |
| 699 | display_cache_file(struct display *dp, const char *filename) |
| 700 | /* Does the initial cache of the file. */ |
| 701 | { |
| 702 | FILE *fp; |
| 703 | int ret; |
| 704 | |
| 705 | dp->filename = filename; |
| 706 | |
| 707 | if (filename != NULL) |
| 708 | { |
| 709 | fp = fopen(filename, "rb"); |
| 710 | if (fp == NULL) |
| 711 | display_log(dp, USER_ERROR, "open failed: %s", strerror(errno)); |
| 712 | } |
| 713 | |
| 714 | else |
| 715 | fp = stdin; |
| 716 | |
| 717 | ret = buffer_from_file(&dp->original_file, fp); |
| 718 | |
| 719 | fclose(fp); |
| 720 | |
| 721 | if (ret != 0) |
| 722 | display_log(dp, APP_ERROR, "read failed: %s", strerror(ret)); |
| 723 | } |
| 724 | |
| 725 | static void |
| 726 | buffer_read(struct display *dp, struct buffer *bp, png_bytep data, |
| 727 | png_size_t size) |
| 728 | { |
| 729 | struct buffer_list *last = bp->current; |
| 730 | size_t read_count = bp->read_count; |
| 731 | |
| 732 | while (size > 0) |
| 733 | { |
| 734 | size_t avail; |
| 735 | |
| 736 | if (last == NULL || |
| 737 | (last == bp->last && read_count >= bp->end_count)) |
| 738 | { |
| 739 | display_log(dp, USER_ERROR, "file truncated (%lu bytes)", |
| 740 | (unsigned long)size); |
| 741 | /*NOTREACHED*/ |
| 742 | break; |
| 743 | } |
| 744 | |
| 745 | else if (read_count >= sizeof last->buffer) |
| 746 | { |
| 747 | /* Move to the next buffer: */ |
| 748 | last = last->next; |
| 749 | read_count = 0; |
| 750 | bp->current = last; /* Avoid update outside the loop */ |
| 751 | |
| 752 | /* And do a sanity check (the EOF case is caught above) */ |
| 753 | if (last == NULL) |
| 754 | { |
| 755 | display_log(dp, INTERNAL_ERROR, "damaged buffer list"); |
| 756 | /*NOTREACHED*/ |
| 757 | break; |
| 758 | } |
| 759 | } |
| 760 | |
| 761 | avail = (sizeof last->buffer) - read_count; |
| 762 | if (avail > size) |
| 763 | avail = size; |
| 764 | |
| 765 | memcpy(data, last->buffer + read_count, avail); |
| 766 | read_count += avail; |
| 767 | size -= avail; |
| 768 | data += avail; |
| 769 | } |
| 770 | |
| 771 | bp->read_count = read_count; |
| 772 | } |
| 773 | |
| 774 | static void PNGCBAPI |
| 775 | read_function(png_structp pp, png_bytep data, png_size_t size) |
| 776 | { |
| 777 | buffer_read(get_dp(pp), get_buffer(pp), data, size); |
| 778 | } |
| 779 | |
| 780 | static void |
| 781 | read_png(struct display *dp, struct buffer *bp, const char *operation, |
| 782 | int transforms) |
| 783 | { |
| 784 | png_structp pp; |
| 785 | png_infop ip; |
| 786 | |
| 787 | /* This cleans out any previous read and sets operation and transforms to |
| 788 | * empty. |
| 789 | */ |
| 790 | display_clean_read(dp); |
| 791 | |
| 792 | if (operation != NULL) /* else this is a verify and do not overwrite info */ |
| 793 | { |
| 794 | dp->operation = operation; |
| 795 | dp->transforms = transforms; |
| 796 | } |
| 797 | |
| 798 | dp->read_pp = pp = png_create_read_struct(PNG_LIBPNG_VER_STRING, dp, |
| 799 | display_error, display_warning); |
| 800 | if (pp == NULL) |
| 801 | display_log(dp, LIBPNG_ERROR, "failed to create read struct"); |
| 802 | |
| 803 | /* The png_read_png API requires us to make the info struct, but it does the |
| 804 | * call to png_read_info. |
| 805 | */ |
| 806 | dp->read_ip = ip = png_create_info_struct(pp); |
| 807 | if (ip == NULL) |
| 808 | display_log(dp, LIBPNG_ERROR, "failed to create info struct"); |
| 809 | |
| 810 | # ifdef PNG_SET_USER_LIMITS_SUPPORTED |
| 811 | /* Remove the user limits, if any */ |
| 812 | png_set_user_limits(pp, 0x7fffffff, 0x7fffffff); |
| 813 | # endif |
| 814 | |
| 815 | /* Set the IO handling */ |
| 816 | buffer_start_read(bp); |
| 817 | png_set_read_fn(pp, bp, read_function); |
| 818 | |
| 819 | png_read_png(pp, ip, transforms, NULL/*params*/); |
| 820 | |
| 821 | #if 0 /* crazy debugging */ |
| 822 | { |
| 823 | png_bytep pr = png_get_rows(pp, ip)[0]; |
| 824 | size_t rb = png_get_rowbytes(pp, ip); |
| 825 | size_t cb; |
| 826 | char c = ' '; |
| 827 | |
| 828 | fprintf(stderr, "%.4x %2d (%3lu bytes):", transforms, png_get_bit_depth(pp,ip), (unsigned long)rb); |
| 829 | |
| 830 | for (cb=0; cb<rb; ++cb) |
| 831 | fputc(c, stderr), fprintf(stderr, "%.2x", pr[cb]), c='.'; |
| 832 | |
| 833 | fputc('\n', stderr); |
| 834 | } |
| 835 | #endif |
| 836 | } |
| 837 | |
| 838 | static void |
| 839 | update_display(struct display *dp) |
| 840 | /* called once after the first read to update all the info, original_pp and |
| 841 | * original_ip must have been filled in. |
| 842 | */ |
| 843 | { |
| 844 | png_structp pp; |
| 845 | png_infop ip; |
| 846 | |
| 847 | /* Now perform the initial read with a 0 tranform. */ |
| 848 | read_png(dp, &dp->original_file, "original read", 0/*no transform*/); |
| 849 | |
| 850 | /* Move the result to the 'original' fields */ |
| 851 | dp->original_pp = pp = dp->read_pp, dp->read_pp = NULL; |
| 852 | dp->original_ip = ip = dp->read_ip, dp->read_ip = NULL; |
| 853 | |
| 854 | dp->original_rowbytes = png_get_rowbytes(pp, ip); |
| 855 | if (dp->original_rowbytes == 0) |
| 856 | display_log(dp, LIBPNG_BUG, "png_get_rowbytes returned 0"); |
| 857 | |
| 858 | dp->chunks = png_get_valid(pp, ip, 0xffffffff); |
| 859 | if ((dp->chunks & PNG_INFO_IDAT) == 0) /* set by png_read_png */ |
| 860 | display_log(dp, LIBPNG_BUG, "png_read_png did not set IDAT flag"); |
| 861 | |
| 862 | dp->original_rows = png_get_rows(pp, ip); |
| 863 | if (dp->original_rows == NULL) |
| 864 | display_log(dp, LIBPNG_BUG, "png_read_png did not create row buffers"); |
| 865 | |
| 866 | if (!png_get_IHDR(pp, ip, |
| 867 | &dp->width, &dp->height, &dp->bit_depth, &dp->color_type, |
| 868 | &dp->interlace_method, &dp->compression_method, &dp->filter_method)) |
| 869 | display_log(dp, LIBPNG_BUG, "png_get_IHDR failed"); |
| 870 | |
| 871 | /* 'active' transforms are discovered based on the original image format; |
| 872 | * running one active transform can activate others. At present the code |
| 873 | * does not attempt to determine the closure. |
| 874 | */ |
| 875 | { |
| 876 | png_uint_32 chunks = dp->chunks; |
| 877 | int active = 0, inactive = 0; |
| 878 | int ct = dp->color_type; |
| 879 | int bd = dp->bit_depth; |
| 880 | unsigned int i; |
| 881 | |
| 882 | for (i=0; i<TTABLE_SIZE; ++i) |
| 883 | { |
| 884 | int transform = transform_info[i].transform; |
| 885 | |
| 886 | if ((transform_info[i].valid_chunks == 0 || |
| 887 | (transform_info[i].valid_chunks & chunks) != 0) && |
| 888 | (transform_info[i].color_mask_required & ct) == |
| 889 | transform_info[i].color_mask_required && |
| 890 | (transform_info[i].color_mask_absent & ct) == 0 && |
| 891 | (transform_info[i].bit_depths & bd) != 0 && |
| 892 | (transform_info[i].when & TRANSFORM_R) != 0) |
| 893 | active |= transform; |
| 894 | |
| 895 | else if ((transform_info[i].when & TRANSFORM_R) != 0) |
| 896 | inactive |= transform; |
| 897 | } |
| 898 | |
| 899 | /* Some transforms appear multiple times in the table; the 'active' status |
| 900 | * is the logical OR of these and the inactive status must be adjusted to |
| 901 | * take this into account. |
| 902 | */ |
| 903 | inactive &= ~active; |
| 904 | |
| 905 | dp->active_transforms = active; |
| 906 | dp->ignored_transforms = inactive; /* excluding write-only transforms */ |
| 907 | |
| 908 | if (active == 0) |
| 909 | display_log(dp, INTERNAL_ERROR, "bad transform table"); |
| 910 | } |
| 911 | } |
| 912 | |
| 913 | static int |
| 914 | compare_read(struct display *dp, int applied_transforms) |
| 915 | { |
| 916 | /* Compare the png_info from read_ip with original_info */ |
| 917 | size_t rowbytes; |
| 918 | png_uint_32 width, height; |
| 919 | int bit_depth, color_type; |
| 920 | int interlace_method, compression_method, filter_method; |
| 921 | const char *e = NULL; |
| 922 | |
| 923 | png_get_IHDR(dp->read_pp, dp->read_ip, &width, &height, &bit_depth, |
| 924 | &color_type, &interlace_method, &compression_method, &filter_method); |
| 925 | |
| 926 | # define C(item) if (item != dp->item) \ |
| 927 | display_log(dp, APP_WARNING, "IHDR " #item "(%lu) changed to %lu",\ |
| 928 | (unsigned long)dp->item, (unsigned long)item), e = #item |
| 929 | |
| 930 | /* The IHDR should be identical: */ |
| 931 | C(width); |
| 932 | C(height); |
| 933 | C(bit_depth); |
| 934 | C(color_type); |
| 935 | C(interlace_method); |
| 936 | C(compression_method); |
| 937 | C(filter_method); |
| 938 | |
| 939 | /* 'e' remains set to the name of the last thing changed: */ |
| 940 | if (e) |
| 941 | display_log(dp, APP_ERROR, "IHDR changed (%s)", e); |
| 942 | |
| 943 | /* All the chunks from the original PNG should be preserved in the output PNG |
| 944 | * because the PNG format has not been changed. |
| 945 | */ |
| 946 | { |
| 947 | unsigned long chunks = |
| 948 | png_get_valid(dp->read_pp, dp->read_ip, 0xffffffff); |
| 949 | |
| 950 | if (chunks != dp->chunks) |
| 951 | display_log(dp, APP_FAIL, "PNG chunks changed from 0x%lx to 0x%lx", |
| 952 | (unsigned long)dp->chunks, chunks); |
| 953 | } |
| 954 | |
| 955 | /* rowbytes should be the same */ |
| 956 | rowbytes = png_get_rowbytes(dp->read_pp, dp->read_ip); |
| 957 | |
| 958 | /* NOTE: on 64-bit systems this may trash the top bits of rowbytes, |
| 959 | * which could lead to weird error messages. |
| 960 | */ |
| 961 | if (rowbytes != dp->original_rowbytes) |
| 962 | display_log(dp, APP_ERROR, "PNG rowbytes changed from %lu to %lu", |
| 963 | (unsigned long)dp->original_rowbytes, (unsigned long)rowbytes); |
| 964 | |
| 965 | /* The rows should be the same too, unless the applied transforms includes |
| 966 | * the shift transform, in which case low bits may have been lost. |
| 967 | */ |
| 968 | { |
| 969 | png_bytepp rows = png_get_rows(dp->read_pp, dp->read_ip); |
| 970 | unsigned int mask; /* mask (if not zero) for the final byte */ |
| 971 | |
| 972 | if (bit_depth < 8) |
| 973 | { |
| 974 | /* Need the stray bits at the end, this depends only on the low bits |
| 975 | * of the image width; overflow does not matter. If the width is an |
| 976 | * exact multiple of 8 bits this gives a mask of 0, not 0xff. |
| 977 | */ |
| 978 | mask = 0xff & (0xff00 >> ((bit_depth * width) & 7)); |
| 979 | } |
| 980 | |
| 981 | else |
| 982 | mask = 0; |
| 983 | |
| 984 | if (rows == NULL) |
| 985 | display_log(dp, LIBPNG_BUG, "png_get_rows returned NULL"); |
| 986 | |
| 987 | if ((applied_transforms & PNG_TRANSFORM_SHIFT) == 0 || |
| 988 | (dp->active_transforms & PNG_TRANSFORM_SHIFT) == 0 || |
| 989 | color_type == PNG_COLOR_TYPE_PALETTE) |
| 990 | { |
| 991 | unsigned long y; |
| 992 | |
| 993 | for (y=0; y<height; ++y) |
| 994 | { |
| 995 | png_bytep row = rows[y]; |
| 996 | png_bytep orig = dp->original_rows[y]; |
| 997 | |
| 998 | if (memcmp(row, orig, rowbytes-(mask != 0)) != 0 || (mask != 0 && |
| 999 | ((row[rowbytes-1] & mask) != (orig[rowbytes-1] & mask)))) |
| 1000 | { |
| 1001 | size_t x; |
| 1002 | |
| 1003 | /* Find the first error */ |
| 1004 | for (x=0; x<rowbytes-1; ++x) if (row[x] != orig[x]) |
| 1005 | break; |
| 1006 | |
| 1007 | display_log(dp, APP_FAIL, |
| 1008 | "byte(%lu,%lu) changed 0x%.2x -> 0x%.2x", |
| 1009 | (unsigned long)x, (unsigned long)y, orig[x], row[x]); |
| 1010 | return 0; /* don't keep reporting failed rows on 'continue' */ |
| 1011 | } |
| 1012 | } |
| 1013 | } |
| 1014 | |
| 1015 | else |
| 1016 | { |
| 1017 | unsigned long y; |
| 1018 | int bpp; /* bits-per-pixel then bytes-per-pixel */ |
| 1019 | /* components are up to 8 bytes in size */ |
| 1020 | png_byte sig_bits[8]; |
| 1021 | png_color_8p sBIT; |
| 1022 | |
| 1023 | if (png_get_sBIT(dp->read_pp, dp->read_ip, &sBIT) != PNG_INFO_sBIT) |
| 1024 | display_log(dp, INTERNAL_ERROR, |
| 1025 | "active shift transform but no sBIT in file"); |
| 1026 | |
| 1027 | switch (color_type) |
| 1028 | { |
| 1029 | case PNG_COLOR_TYPE_GRAY: |
| 1030 | sig_bits[0] = sBIT->gray; |
| 1031 | bpp = bit_depth; |
| 1032 | break; |
| 1033 | |
| 1034 | case PNG_COLOR_TYPE_GA: |
| 1035 | sig_bits[0] = sBIT->gray; |
| 1036 | sig_bits[1] = sBIT->alpha; |
| 1037 | bpp = 2 * bit_depth; |
| 1038 | break; |
| 1039 | |
| 1040 | case PNG_COLOR_TYPE_RGB: |
| 1041 | sig_bits[0] = sBIT->red; |
| 1042 | sig_bits[1] = sBIT->green; |
| 1043 | sig_bits[2] = sBIT->blue; |
| 1044 | bpp = 3 * bit_depth; |
| 1045 | break; |
| 1046 | |
| 1047 | case PNG_COLOR_TYPE_RGBA: |
| 1048 | sig_bits[0] = sBIT->red; |
| 1049 | sig_bits[1] = sBIT->green; |
| 1050 | sig_bits[2] = sBIT->blue; |
| 1051 | sig_bits[3] = sBIT->alpha; |
| 1052 | bpp = 4 * bit_depth; |
| 1053 | break; |
| 1054 | |
| 1055 | default: |
| 1056 | display_log(dp, LIBPNG_ERROR, "invalid colour type %d", |
| 1057 | color_type); |
| 1058 | /*NOTREACHED*/ |
| 1059 | bpp = 0; |
| 1060 | break; |
| 1061 | } |
| 1062 | |
| 1063 | { |
| 1064 | int b; |
| 1065 | |
| 1066 | for (b=0; 8*b<bpp; ++b) |
| 1067 | { |
| 1068 | /* libpng should catch this; if not there is a security issue |
| 1069 | * because an app (like this one) may overflow an array. In fact |
| 1070 | * libpng doesn't catch this at present. |
| 1071 | */ |
| 1072 | if (sig_bits[b] == 0 || sig_bits[b] > bit_depth/*!palette*/) |
| 1073 | display_log(dp, LIBPNG_BUG, |
| 1074 | "invalid sBIT[%u] value %d returned for PNG bit depth %d", |
| 1075 | b, sig_bits[b], bit_depth); |
| 1076 | } |
| 1077 | } |
| 1078 | |
| 1079 | if (bpp < 8 && bpp != bit_depth) |
| 1080 | { |
| 1081 | /* sanity check; this is a grayscale PNG; something is wrong in the |
| 1082 | * code above. |
| 1083 | */ |
| 1084 | display_log(dp, INTERNAL_ERROR, "invalid bpp %u for bit_depth %u", |
| 1085 | bpp, bit_depth); |
| 1086 | } |
| 1087 | |
| 1088 | switch (bit_depth) |
| 1089 | { |
| 1090 | int b; |
| 1091 | |
| 1092 | case 16: /* Two bytes per component, bit-endian */ |
| 1093 | for (b = (bpp >> 4); b > 0; ) |
| 1094 | { |
| 1095 | unsigned int sig = (unsigned int)(0xffff0000 >> sig_bits[b]); |
| 1096 | |
| 1097 | sig_bits[2*b+1] = (png_byte)sig; |
| 1098 | sig_bits[2*b+0] = (png_byte)(sig >> 8); /* big-endian */ |
| 1099 | } |
| 1100 | break; |
| 1101 | |
| 1102 | case 8: /* One byte per component */ |
| 1103 | for (b=0; b*8 < bpp; ++b) |
| 1104 | sig_bits[b] = (png_byte)(0xff00 >> sig_bits[b]); |
| 1105 | break; |
| 1106 | |
| 1107 | case 1: /* allowed, but dumb */ |
| 1108 | /* Value is 1 */ |
| 1109 | sig_bits[0] = 0xff; |
| 1110 | break; |
| 1111 | |
| 1112 | case 2: /* Replicate 4 times */ |
| 1113 | /* Value is 1 or 2 */ |
| 1114 | b = 0x3 & ((0x3<<2) >> sig_bits[0]); |
| 1115 | b |= b << 2; |
| 1116 | b |= b << 4; |
| 1117 | sig_bits[0] = (png_byte)b; |
| 1118 | break; |
| 1119 | |
| 1120 | case 4: /* Relicate twice */ |
| 1121 | /* Value is 1, 2, 3 or 4 */ |
| 1122 | b = 0xf & ((0xf << 4) >> sig_bits[0]); |
| 1123 | b |= b << 4; |
| 1124 | sig_bits[0] = (png_byte)b; |
| 1125 | break; |
| 1126 | |
| 1127 | default: |
| 1128 | display_log(dp, LIBPNG_BUG, "invalid bit depth %d", bit_depth); |
| 1129 | break; |
| 1130 | } |
| 1131 | |
| 1132 | /* Convert bpp to bytes; this gives '1' for low-bit depth grayscale, |
| 1133 | * where there are multiple pixels per byte. |
| 1134 | */ |
| 1135 | bpp = (bpp+7) >> 3; |
| 1136 | |
| 1137 | /* The mask can be combined with sig_bits[0] */ |
| 1138 | if (mask != 0) |
| 1139 | { |
| 1140 | mask &= sig_bits[0]; |
| 1141 | |
| 1142 | if (bpp != 1 || mask == 0) |
| 1143 | display_log(dp, INTERNAL_ERROR, "mask calculation error %u, %u", |
| 1144 | bpp, mask); |
| 1145 | } |
| 1146 | |
| 1147 | for (y=0; y<height; ++y) |
| 1148 | { |
| 1149 | png_bytep row = rows[y]; |
| 1150 | png_bytep orig = dp->original_rows[y]; |
| 1151 | unsigned long x; |
| 1152 | |
| 1153 | for (x=0; x<(width-(mask!=0)); ++x) |
| 1154 | { |
| 1155 | int b; |
| 1156 | |
| 1157 | for (b=0; b<bpp; ++b) |
| 1158 | { |
| 1159 | if ((*row++ & sig_bits[b]) != (*orig++ & sig_bits[b])) |
| 1160 | { |
| 1161 | display_log(dp, APP_FAIL, |
| 1162 | "significant bits at (%lu[%u],%lu) changed %.2x->%.2x", |
| 1163 | x, b, y, orig[-1], row[-1]); |
| 1164 | return 0; |
| 1165 | } |
| 1166 | } |
| 1167 | } |
| 1168 | |
| 1169 | if (mask != 0 && (*row & mask) != (*orig & mask)) |
| 1170 | { |
| 1171 | display_log(dp, APP_FAIL, |
| 1172 | "significant bits at (%lu[end],%lu) changed", x, y); |
| 1173 | return 0; |
| 1174 | } |
| 1175 | } /* for y */ |
| 1176 | } |
| 1177 | } |
| 1178 | |
| 1179 | return 1; /* compare succeeded */ |
| 1180 | } |
| 1181 | |
| 1182 | #ifdef PNG_WRITE_SUPPORTED |
| 1183 | static void |
| 1184 | buffer_write(struct display *dp, struct buffer *buffer, png_bytep data, |
| 1185 | png_size_t size) |
| 1186 | /* Generic write function used both from the write callback provided to |
| 1187 | * libpng and from the generic read code. |
| 1188 | */ |
| 1189 | { |
| 1190 | /* Write the data into the buffer, adding buffers as required */ |
| 1191 | struct buffer_list *last = buffer->last; |
| 1192 | size_t end_count = buffer->end_count; |
| 1193 | |
| 1194 | while (size > 0) |
| 1195 | { |
| 1196 | size_t avail; |
| 1197 | |
| 1198 | if (end_count >= sizeof last->buffer) |
| 1199 | { |
| 1200 | if (last->next == NULL) |
| 1201 | { |
| 1202 | last = buffer_extend(last); |
| 1203 | |
| 1204 | if (last == NULL) |
| 1205 | display_log(dp, APP_ERROR, "out of memory saving file"); |
| 1206 | } |
| 1207 | |
| 1208 | else |
| 1209 | last = last->next; |
| 1210 | |
| 1211 | buffer->last = last; /* avoid the need to rewrite every time */ |
| 1212 | end_count = 0; |
| 1213 | } |
| 1214 | |
| 1215 | avail = (sizeof last->buffer) - end_count; |
| 1216 | if (avail > size) |
| 1217 | avail = size; |
| 1218 | |
| 1219 | memcpy(last->buffer + end_count, data, avail); |
| 1220 | end_count += avail; |
| 1221 | size -= avail; |
| 1222 | data += avail; |
| 1223 | } |
| 1224 | |
| 1225 | buffer->end_count = end_count; |
| 1226 | } |
| 1227 | |
| 1228 | static void PNGCBAPI |
| 1229 | write_function(png_structp pp, png_bytep data, png_size_t size) |
| 1230 | { |
| 1231 | buffer_write(get_dp(pp), get_buffer(pp), data, size); |
| 1232 | } |
| 1233 | |
| 1234 | static void |
| 1235 | write_png(struct display *dp, png_infop ip, int transforms) |
| 1236 | { |
| 1237 | display_clean_write(dp); /* safety */ |
| 1238 | |
| 1239 | buffer_start_write(&dp->written_file); |
| 1240 | dp->operation = "write"; |
| 1241 | dp->transforms = transforms; |
| 1242 | |
| 1243 | dp->write_pp = png_create_write_struct(PNG_LIBPNG_VER_STRING, dp, |
| 1244 | display_error, display_warning); |
| 1245 | |
| 1246 | if (dp->write_pp == NULL) |
| 1247 | display_log(dp, APP_ERROR, "failed to create write png_struct"); |
| 1248 | |
| 1249 | png_set_write_fn(dp->write_pp, &dp->written_file, write_function, |
| 1250 | NULL/*flush*/); |
| 1251 | |
| 1252 | # ifdef PNG_SET_USER_LIMITS_SUPPORTED |
| 1253 | /* Remove the user limits, if any */ |
| 1254 | png_set_user_limits(dp->write_pp, 0x7fffffff, 0x7fffffff); |
| 1255 | # endif |
| 1256 | |
| 1257 | /* Certain transforms require the png_info to be zapped to allow the |
| 1258 | * transform to work correctly. |
| 1259 | */ |
| 1260 | if (transforms & (PNG_TRANSFORM_PACKING| |
| 1261 | PNG_TRANSFORM_STRIP_FILLER| |
| 1262 | PNG_TRANSFORM_STRIP_FILLER_BEFORE)) |
| 1263 | { |
| 1264 | int ct = dp->color_type; |
| 1265 | |
| 1266 | if (transforms & (PNG_TRANSFORM_STRIP_FILLER| |
| 1267 | PNG_TRANSFORM_STRIP_FILLER_BEFORE)) |
| 1268 | ct &= ~PNG_COLOR_MASK_ALPHA; |
| 1269 | |
| 1270 | png_set_IHDR(dp->write_pp, ip, dp->width, dp->height, dp->bit_depth, ct, |
| 1271 | dp->interlace_method, dp->compression_method, dp->filter_method); |
| 1272 | } |
| 1273 | |
| 1274 | png_write_png(dp->write_pp, ip, transforms, NULL/*params*/); |
| 1275 | |
| 1276 | /* Clean it on the way out - if control returns to the caller then the |
| 1277 | * written_file contains the required data. |
| 1278 | */ |
| 1279 | display_clean_write(dp); |
| 1280 | } |
| 1281 | #endif /* WRITE_SUPPORTED */ |
| 1282 | |
| 1283 | static int |
| 1284 | skip_transform(struct display *dp, int tr) |
| 1285 | /* Helper to test for a bad combo and log it if it is skipped */ |
| 1286 | { |
| 1287 | if ((dp->options & SKIP_BUGS) != 0 && is_bad_combo(tr)) |
| 1288 | { |
| 1289 | /* Log this to stdout if logging is on, otherwise just do an information |
| 1290 | * display_log. |
| 1291 | */ |
| 1292 | if ((dp->options & LOG_SKIPPED) != 0) |
| 1293 | { |
| 1294 | printf("SKIP: %s transforms ", dp->filename); |
| 1295 | |
| 1296 | while (tr != 0) |
| 1297 | { |
| 1298 | int next = first_transform(tr); |
| 1299 | tr &= ~next; |
| 1300 | |
| 1301 | printf("%s", transform_name(next)); |
| 1302 | if (tr != 0) |
| 1303 | putchar('+'); |
| 1304 | } |
| 1305 | |
| 1306 | putchar('\n'); |
| 1307 | } |
| 1308 | |
| 1309 | else |
| 1310 | display_log(dp, INFORMATION, "%s: skipped known bad combo 0x%x", |
| 1311 | dp->filename, tr); |
| 1312 | |
| 1313 | return 1; /* skip */ |
| 1314 | } |
| 1315 | |
| 1316 | return 0; /* don't skip */ |
| 1317 | } |
| 1318 | |
| 1319 | static void |
| 1320 | test_one_file(struct display *dp, const char *filename) |
| 1321 | { |
| 1322 | /* First cache the file and update the display original file |
| 1323 | * information for the new file. |
| 1324 | */ |
| 1325 | dp->operation = "cache file"; |
| 1326 | dp->transforms = 0; |
| 1327 | display_cache_file(dp, filename); |
| 1328 | update_display(dp); |
| 1329 | |
| 1330 | /* First test: if there are options that should be ignored for this file |
| 1331 | * verify that they really are ignored. |
| 1332 | */ |
| 1333 | if (dp->ignored_transforms != 0) |
| 1334 | { |
| 1335 | read_png(dp, &dp->original_file, "ignored transforms", |
| 1336 | dp->ignored_transforms); |
| 1337 | |
| 1338 | /* The result should be identical to the original_rows */ |
| 1339 | if (!compare_read(dp, 0/*transforms applied*/)) |
| 1340 | return; /* no point testing more */ |
| 1341 | } |
| 1342 | |
| 1343 | #ifdef PNG_WRITE_SUPPORTED |
| 1344 | /* Second test: write the original PNG data out to a new file (to test the |
| 1345 | * write side) then read the result back in and make sure that it hasn't |
| 1346 | * changed. |
| 1347 | */ |
| 1348 | dp->operation = "write"; |
| 1349 | write_png(dp, dp->original_ip, 0/*transforms*/); |
| 1350 | read_png(dp, &dp->written_file, NULL, 0/*transforms*/); |
| 1351 | if (!compare_read(dp, 0/*transforms applied*/)) |
| 1352 | return; |
| 1353 | #endif |
| 1354 | |
| 1355 | /* Third test: the active options. Test each in turn, or, with the |
| 1356 | * EXHAUSTIVE option, test all possible combinations. |
| 1357 | */ |
| 1358 | { |
| 1359 | /* Use unsigned int here because the code below to increment through all |
| 1360 | * the possibilities exhaustively has to use a compare and that must be |
| 1361 | * unsigned, because some transforms are negative on a 16-bit system. |
| 1362 | */ |
| 1363 | unsigned int active = dp->active_transforms; |
| 1364 | const int exhaustive = (dp->options & EXHAUSTIVE) != 0; |
| 1365 | unsigned int current = first_transform(active); |
| 1366 | unsigned int bad_transforms = 0; |
| 1367 | unsigned int bad_combo = ~0U; /* bitwise AND of failing transforms */ |
| 1368 | unsigned int bad_combo_list = 0; /* bitwise OR of failures */ |
| 1369 | |
| 1370 | for (;;) |
| 1371 | { |
| 1372 | read_png(dp, &dp->original_file, "active transforms", current); |
| 1373 | |
| 1374 | /* If this involved any irreversible transformations then if we write |
| 1375 | * it out with just the reversible transformations and read it in again |
| 1376 | * with the same transforms we should get the same thing. At present |
| 1377 | * this isn't done - it just seems like a waste of time and it would |
| 1378 | * require two sets of read png_struct/png_info. |
| 1379 | * |
| 1380 | * If there were no irreversible transformations then if we write it |
| 1381 | * out and read it back in again (without the reversible transforms) |
| 1382 | * we should get back to the place where we started. |
| 1383 | */ |
| 1384 | #ifdef PNG_WRITE_SUPPORTED |
| 1385 | if ((current & write_transforms) == current) |
| 1386 | { |
| 1387 | /* All transforms reversible: write the PNG with the transformations |
| 1388 | * reversed, then read it back in with no transformations. The |
| 1389 | * result should be the same as the original apart from the loss of |
| 1390 | * low order bits because of the SHIFT/sBIT transform. |
| 1391 | */ |
| 1392 | dp->operation = "reversible transforms"; |
| 1393 | write_png(dp, dp->read_ip, current); |
| 1394 | |
| 1395 | /* And if this is read back in, because all the transformations were |
| 1396 | * reversible, the result should be the same. |
| 1397 | */ |
| 1398 | read_png(dp, &dp->written_file, NULL, 0); |
| 1399 | if (!compare_read(dp, current/*for the SHIFT/sBIT transform*/)) |
| 1400 | { |
| 1401 | /* This set of transforms failed. If a single bit is set - if |
| 1402 | * there is just one transform - don't include this in further |
| 1403 | * 'exhaustive' tests. Notice that each transform is tested on |
| 1404 | * its own before testing combos in the exhaustive case. |
| 1405 | */ |
| 1406 | if (is_combo(current)) |
| 1407 | { |
| 1408 | bad_combo &= current; |
| 1409 | bad_combo_list |= current; |
| 1410 | } |
| 1411 | |
| 1412 | else |
| 1413 | bad_transforms |= current; |
| 1414 | } |
| 1415 | } |
| 1416 | #endif |
| 1417 | |
| 1418 | /* Now move to the next transform */ |
| 1419 | if (exhaustive) /* all combinations */ |
| 1420 | { |
| 1421 | unsigned int next = current; |
| 1422 | |
| 1423 | do |
| 1424 | { |
| 1425 | if (next == read_transforms) /* Everything tested */ |
| 1426 | goto combo; |
| 1427 | |
| 1428 | ++next; |
| 1429 | } /* skip known bad combos if the relevant option is set; skip |
| 1430 | * combos involving known bad single transforms in all cases. |
| 1431 | */ |
| 1432 | while ( (next & read_transforms) <= current |
| 1433 | || (next & active) == 0 /* skip cases that do nothing */ |
| 1434 | || (next & bad_transforms) != 0 |
| 1435 | || skip_transform(dp, next)); |
| 1436 | |
| 1437 | assert((next & read_transforms) == next); |
| 1438 | current = next; |
| 1439 | } |
| 1440 | |
| 1441 | else /* one at a time */ |
| 1442 | { |
| 1443 | active &= ~current; |
| 1444 | |
| 1445 | if (active == 0) |
| 1446 | goto combo; |
| 1447 | |
| 1448 | current = first_transform(active); |
| 1449 | } |
| 1450 | } |
| 1451 | |
| 1452 | combo: |
| 1453 | if (dp->options & FIND_BAD_COMBOS) |
| 1454 | { |
| 1455 | /* bad_combos identifies the combos that occur in all failing cases; |
| 1456 | * bad_combo_list identifies transforms that do not prevent the |
| 1457 | * failure. |
| 1458 | */ |
| 1459 | if (bad_combo != ~0U) |
| 1460 | printf("%s[0x%x]: PROBLEM: 0x%x[0x%x] ANTIDOTE: 0x%x\n", |
| 1461 | dp->filename, active, bad_combo, bad_combo_list, |
| 1462 | rw_transforms & ~bad_combo_list); |
| 1463 | |
| 1464 | else |
| 1465 | printf("%s: no %sbad combos found\n", dp->filename, |
| 1466 | (dp->options & SKIP_BUGS) ? "additional " : ""); |
| 1467 | } |
| 1468 | } |
| 1469 | } |
| 1470 | |
| 1471 | static int |
| 1472 | do_test(struct display *dp, const char *file) |
| 1473 | /* Exists solely to isolate the setjmp clobbers */ |
| 1474 | { |
| 1475 | int ret = setjmp(dp->error_return); |
| 1476 | |
| 1477 | if (ret == 0) |
| 1478 | { |
| 1479 | test_one_file(dp, file); |
| 1480 | return 0; |
| 1481 | } |
| 1482 | |
| 1483 | else if (ret < ERRORS) /* shouldn't longjmp on warnings */ |
| 1484 | display_log(dp, INTERNAL_ERROR, "unexpected return code %d", ret); |
| 1485 | |
| 1486 | return ret; |
| 1487 | } |
| 1488 | |
| 1489 | int |
| 1490 | main(const int argc, const char * const * const argv) |
| 1491 | { |
| 1492 | /* For each file on the command line test it with a range of transforms */ |
| 1493 | int option_end, ilog = 0; |
| 1494 | struct display d; |
| 1495 | |
| 1496 | validate_T(); |
| 1497 | display_init(&d); |
| 1498 | |
| 1499 | for (option_end=1; option_end<argc; ++option_end) |
| 1500 | { |
| 1501 | const char *name = argv[option_end]; |
| 1502 | |
| 1503 | if (strcmp(name, "--verbose") == 0) |
| 1504 | d.options = (d.options & ~LEVEL_MASK) | VERBOSE; |
| 1505 | |
| 1506 | else if (strcmp(name, "--warnings") == 0) |
| 1507 | d.options = (d.options & ~LEVEL_MASK) | WARNINGS; |
| 1508 | |
| 1509 | else if (strcmp(name, "--errors") == 0) |
| 1510 | d.options = (d.options & ~LEVEL_MASK) | ERRORS; |
| 1511 | |
| 1512 | else if (strcmp(name, "--quiet") == 0) |
| 1513 | d.options = (d.options & ~LEVEL_MASK) | QUIET; |
| 1514 | |
| 1515 | else if (strcmp(name, "--exhaustive") == 0) |
| 1516 | d.options |= EXHAUSTIVE; |
| 1517 | |
| 1518 | else if (strcmp(name, "--fast") == 0) |
| 1519 | d.options &= ~EXHAUSTIVE; |
| 1520 | |
| 1521 | else if (strcmp(name, "--strict") == 0) |
| 1522 | d.options |= STRICT; |
| 1523 | |
| 1524 | else if (strcmp(name, "--relaxed") == 0) |
| 1525 | d.options &= ~STRICT; |
| 1526 | |
| 1527 | else if (strcmp(name, "--log") == 0) |
| 1528 | { |
| 1529 | ilog = option_end; /* prevent display */ |
| 1530 | d.options |= LOG; |
| 1531 | } |
| 1532 | |
| 1533 | else if (strcmp(name, "--nolog") == 0) |
| 1534 | d.options &= ~LOG; |
| 1535 | |
| 1536 | else if (strcmp(name, "--continue") == 0) |
| 1537 | d.options |= CONTINUE; |
| 1538 | |
| 1539 | else if (strcmp(name, "--stop") == 0) |
| 1540 | d.options &= ~CONTINUE; |
| 1541 | |
| 1542 | else if (strcmp(name, "--skip-bugs") == 0) |
| 1543 | d.options |= SKIP_BUGS; |
| 1544 | |
| 1545 | else if (strcmp(name, "--test-all") == 0) |
| 1546 | d.options &= ~SKIP_BUGS; |
| 1547 | |
| 1548 | else if (strcmp(name, "--log-skipped") == 0) |
| 1549 | d.options |= LOG_SKIPPED; |
| 1550 | |
| 1551 | else if (strcmp(name, "--nolog-skipped") == 0) |
| 1552 | d.options &= ~LOG_SKIPPED; |
| 1553 | |
| 1554 | else if (strcmp(name, "--find-bad-combos") == 0) |
| 1555 | d.options |= FIND_BAD_COMBOS; |
| 1556 | |
| 1557 | else if (strcmp(name, "--nofind-bad-combos") == 0) |
| 1558 | d.options &= ~FIND_BAD_COMBOS; |
| 1559 | |
| 1560 | else if (name[0] == '-' && name[1] == '-') |
| 1561 | { |
| 1562 | fprintf(stderr, "pngimage: %s: unknown option\n", name); |
| 1563 | return 99; |
| 1564 | } |
| 1565 | |
| 1566 | else |
| 1567 | break; /* Not an option */ |
| 1568 | } |
| 1569 | |
| 1570 | { |
| 1571 | int i; |
| 1572 | int errors = 0; |
| 1573 | |
| 1574 | for (i=option_end; i<argc; ++i) |
| 1575 | { |
| 1576 | { |
| 1577 | int ret = do_test(&d, argv[i]); |
| 1578 | |
| 1579 | if (ret > QUIET) /* abort on user or internal error */ |
| 1580 | return 99; |
| 1581 | } |
| 1582 | |
| 1583 | /* Here on any return, including failures, except user/internal issues |
| 1584 | */ |
| 1585 | { |
| 1586 | const int pass = (d.options & STRICT) ? |
| 1587 | RESULT_STRICT(d.results) : RESULT_RELAXED(d.results); |
| 1588 | |
| 1589 | if (!pass) |
| 1590 | ++errors; |
| 1591 | |
| 1592 | if (d.options & LOG) |
| 1593 | { |
| 1594 | int j; |
| 1595 | |
| 1596 | printf("%s: pngimage ", pass ? "PASS" : "FAIL"); |
| 1597 | |
| 1598 | for (j=1; j<option_end; ++j) if (j != ilog) |
| 1599 | printf("%s ", argv[j]); |
| 1600 | |
| 1601 | printf("%s\n", d.filename); |
| 1602 | } |
| 1603 | } |
| 1604 | |
| 1605 | display_clean(&d); |
| 1606 | } |
| 1607 | |
| 1608 | return errors != 0; |
| 1609 | } |
| 1610 | } |
| 1611 | #else /* !PNG_INFO_IMAGE_SUPPORTED || !PNG_READ_SUPPORTED */ |
| 1612 | int |
| 1613 | main(void) |
| 1614 | { |
| 1615 | fprintf(stderr, "pngimage: no support for png_read/write_image\n"); |
| 1616 | return 77; |
| 1617 | } |
| 1618 | #endif |