| 1 | // picoPNG version 20080503 (cleaned up and ported to c by kaitek)␊ |
| 2 | // Copyright (c) 2005-2008 Lode Vandevenne␊ |
| 3 | //␊ |
| 4 | // This software is provided 'as-is', without any express or implied␊ |
| 5 | // warranty. In no event will the authors be held liable for any damages␊ |
| 6 | // arising from the use of this software.␊ |
| 7 | //␊ |
| 8 | // Permission is granted to anyone to use this software for any purpose,␊ |
| 9 | // including commercial applications, and to alter it and redistribute it␊ |
| 10 | // freely, subject to the following restrictions:␊ |
| 11 | //␊ |
| 12 | // 1. The origin of this software must not be misrepresented; you must not␊ |
| 13 | // claim that you wrote the original software. If you use this software␊ |
| 14 | // in a product, an acknowledgment in the product documentation would be␊ |
| 15 | // appreciated but is not required.␊ |
| 16 | // 2. Altered source versions must be plainly marked as such, and must not be␊ |
| 17 | // misrepresented as being the original software.␊ |
| 18 | // 3. This notice may not be removed or altered from any source distribution.␊ |
| 19 | ␊ |
| 20 | #include <sys/types.h>␊ |
| 21 | #include "libsa.h"␊ |
| 22 | #include "picopng.h"␊ |
| 23 | ␊ |
| 24 | /*************************************************************************************************/␊ |
| 25 | ␊ |
| 26 | typedef struct png_alloc_node {␊ |
| 27 | ␉struct png_alloc_node *prev, *next;␊ |
| 28 | ␉void *addr;␊ |
| 29 | ␉size_t size;␊ |
| 30 | } png_alloc_node_t;␊ |
| 31 | ␊ |
| 32 | png_alloc_node_t *png_alloc_head = NULL;␊ |
| 33 | png_alloc_node_t *png_alloc_tail = NULL;␊ |
| 34 | ␊ |
| 35 | png_alloc_node_t *png_alloc_find_node(void *addr)␊ |
| 36 | {␊ |
| 37 | ␉png_alloc_node_t *node;␊ |
| 38 | ␉for (node = png_alloc_head; node; node = node->next)␊ |
| 39 | ␉␉if (node->addr == addr)␊ |
| 40 | ␉␉␉break;␊ |
| 41 | ␉return node;␊ |
| 42 | }␊ |
| 43 | ␊ |
| 44 | void png_alloc_add_node(void *addr, size_t size)␊ |
| 45 | {␊ |
| 46 | ␉png_alloc_node_t *node;␊ |
| 47 | ␉if (png_alloc_find_node(addr))␊ |
| 48 | ␉␉return;␊ |
| 49 | ␉node = malloc(sizeof (png_alloc_node_t));␊ |
| 50 | ␉node->addr = addr;␊ |
| 51 | ␉node->size = size;␊ |
| 52 | ␉node->prev = png_alloc_tail;␊ |
| 53 | ␉node->next = NULL;␊ |
| 54 | ␉png_alloc_tail = node;␊ |
| 55 | ␉if (node->prev)␊ |
| 56 | ␉␉node->prev->next = node;␊ |
| 57 | ␉if (!png_alloc_head)␊ |
| 58 | ␉␉png_alloc_head = node;␊ |
| 59 | }␊ |
| 60 | ␊ |
| 61 | void png_alloc_remove_node(png_alloc_node_t *node)␊ |
| 62 | {␊ |
| 63 | ␉if (!node)␊ |
| 64 | ␉{␊ |
| 65 | ␉␉return;␊ |
| 66 | ␉}␊ |
| 67 | ␉if (node->prev)␊ |
| 68 | ␉{␊ |
| 69 | ␉␉node->prev->next = node->next;␊ |
| 70 | ␉}␊ |
| 71 | ␉if (node->next)␊ |
| 72 | ␉{␊ |
| 73 | ␉␉node->next->prev = node->prev;␊ |
| 74 | ␉}␊ |
| 75 | ␉if (node == png_alloc_head)␊ |
| 76 | ␉{␊ |
| 77 | ␉␉png_alloc_head = node->next;␊ |
| 78 | ␉}␊ |
| 79 | ␉if (node == png_alloc_tail)␊ |
| 80 | ␉{␊ |
| 81 | ␉␉png_alloc_tail = node->prev;␊ |
| 82 | ␉}␊ |
| 83 | ␉node->prev = node->next = node->addr = NULL;␊ |
| 84 | ␉free(node);␊ |
| 85 | }␊ |
| 86 | ␊ |
| 87 | void *png_alloc_malloc(size_t size)␊ |
| 88 | {␊ |
| 89 | ␉void *addr = malloc(size);␊ |
| 90 | ␉png_alloc_add_node(addr, size);␊ |
| 91 | ␉return addr;␊ |
| 92 | }␊ |
| 93 | ␊ |
| 94 | void *png_alloc_realloc(void *addr, size_t size)␊ |
| 95 | {␊ |
| 96 | ␉void *new_addr = NULL;␊ |
| 97 | ␉if (!addr)␊ |
| 98 | ␉{␊ |
| 99 | ␉␉return png_alloc_malloc(size);␊ |
| 100 | ␉}␊ |
| 101 | ␊ |
| 102 | ␉png_alloc_node_t *old_node;␊ |
| 103 | ␉old_node = png_alloc_find_node(addr);␊ |
| 104 | ␊ |
| 105 | ␉if (old_node)␊ |
| 106 | ␉{␊ |
| 107 | ␉␉new_addr = realloc(addr, size);␊ |
| 108 | ␉␉if (new_addr && (new_addr != addr))␊ |
| 109 | ␉␉{␊ |
| 110 | ␉␉␉png_alloc_remove_node(old_node);␊ |
| 111 | ␉␉␉png_alloc_add_node(new_addr, size);␊ |
| 112 | ␉␉}␊ |
| 113 | ␉}␊ |
| 114 | ␊ |
| 115 | ␉return new_addr;␊ |
| 116 | }␊ |
| 117 | ␊ |
| 118 | void png_alloc_free(void *addr)␊ |
| 119 | {␊ |
| 120 | if (!addr) return;␊ |
| 121 | ␊ |
| 122 | ␉png_alloc_node_t *node = png_alloc_find_node(addr);␊ |
| 123 | ␉if (node)␊ |
| 124 | ␉␉png_alloc_remove_node(node);␊ |
| 125 | ␊ |
| 126 | ␉free(addr);␊ |
| 127 | }␊ |
| 128 | ␊ |
| 129 | void png_alloc_free_all()␊ |
| 130 | {␊ |
| 131 | ␉while (png_alloc_tail) {␊ |
| 132 | ␉␉void *addr = png_alloc_tail->addr;␊ |
| 133 | ␉␉png_alloc_remove_node(png_alloc_tail);␊ |
| 134 | ␉␉free(addr);␊ |
| 135 | ␉}␊ |
| 136 | }␊ |
| 137 | ␊ |
| 138 | /*************************************************************************************************/␊ |
| 139 | ␊ |
| 140 | __unused void vector32_cleanup(vector32_t *p)␊ |
| 141 | {␊ |
| 142 | ␉p->size = p->allocsize = 0;␊ |
| 143 | ␉if (p->data)␊ |
| 144 | ␉␉png_alloc_free(p->data);␊ |
| 145 | ␉p->data = NULL;␊ |
| 146 | }␊ |
| 147 | ␊ |
| 148 | uint32_t vector32_resize(vector32_t *p, size_t size)␊ |
| 149 | {␉// returns 1 if success, 0 if failure ==> nothing done␊ |
| 150 | ␉if (size * sizeof (uint32_t) > p->allocsize)␊ |
| 151 | ␉{␊ |
| 152 | ␉␉size_t newsize = size * sizeof (uint32_t) * 2;␊ |
| 153 | ␉␉void *data = png_alloc_realloc(p->data, newsize);␊ |
| 154 | ␉␉if (data)␊ |
| 155 | ␉␉{␊ |
| 156 | ␉␉␉p->allocsize = newsize;␊ |
| 157 | ␉␉␉p->data = (uint32_t *) data;␊ |
| 158 | ␉␉␉p->size = size;␊ |
| 159 | ␉␉} else␊ |
| 160 | ␉␉␉return 0;␊ |
| 161 | ␉}␊ |
| 162 | ␉else␊ |
| 163 | ␉␉p->size = size;␊ |
| 164 | ␉return 1;␊ |
| 165 | }␊ |
| 166 | ␊ |
| 167 | uint32_t vector32_resizev(vector32_t *p, size_t size, uint32_t value)␊ |
| 168 | {␉// resize and give all new elements the value␊ |
| 169 | ␉size_t oldsize = p->size, i;␊ |
| 170 | ␉if (!vector32_resize(p, size))␊ |
| 171 | ␉␉return 0;␊ |
| 172 | ␉for (i = oldsize; i < size; i++)␊ |
| 173 | ␉␉p->data[i] = value;␊ |
| 174 | ␉return 1;␊ |
| 175 | }␊ |
| 176 | ␊ |
| 177 | void vector32_init(vector32_t *p)␊ |
| 178 | {␊ |
| 179 | ␉p->data = NULL;␊ |
| 180 | ␉p->size = p->allocsize = 0;␊ |
| 181 | }␊ |
| 182 | ␊ |
| 183 | vector32_t *vector32_new(size_t size, uint32_t value)␊ |
| 184 | {␊ |
| 185 | ␉vector32_t *p = png_alloc_malloc(sizeof (vector32_t));␊ |
| 186 | ␉if (!p)␊ |
| 187 | ␉{␊ |
| 188 | ␉␉return NULL;␊ |
| 189 | ␉}␊ |
| 190 | ␉vector32_init(p);␊ |
| 191 | ␉if (size && !vector32_resizev(p, size, value))␊ |
| 192 | ␉{␊ |
| 193 | ␉␉vector32_cleanup(p);␊ |
| 194 | ␉␉png_alloc_free(p);␊ |
| 195 | ␉␉return NULL;␊ |
| 196 | ␉}␊ |
| 197 | ␉return p;␊ |
| 198 | }␊ |
| 199 | ␊ |
| 200 | /*************************************************************************************************/␊ |
| 201 | ␊ |
| 202 | __unused void vector8_cleanup(vector8_t *p)␊ |
| 203 | {␊ |
| 204 | ␉p->size = p->allocsize = 0;␊ |
| 205 | ␉if (p->data)␊ |
| 206 | ␉␉png_alloc_free(p->data);␊ |
| 207 | ␉p->data = NULL;␊ |
| 208 | }␊ |
| 209 | ␊ |
| 210 | uint32_t vector8_resize(vector8_t *p, size_t size)␊ |
| 211 | {␉// returns 1 if success, 0 if failure ==> nothing done␊ |
| 212 | ␉// xxx: the use of sizeof uint32_t here seems like a bug (this descends from the lodepng vector␊ |
| 213 | ␉// compatibility functions which do the same). without this there is corruption in certain cases,␊ |
| 214 | ␉// so this was probably done to cover up allocation bug(s) in the original picopng code!␊ |
| 215 | ␉if (size * sizeof (uint32_t) > p->allocsize)␊ |
| 216 | ␉{␊ |
| 217 | ␉␉size_t newsize = size * sizeof (uint32_t) * 2;␊ |
| 218 | ␉␉void *data = png_alloc_realloc(p->data, newsize);␊ |
| 219 | ␉␉if (data)␊ |
| 220 | ␉␉{␊ |
| 221 | ␉␉␉p->allocsize = newsize;␊ |
| 222 | ␉␉␉p->data = (uint8_t *) data;␊ |
| 223 | ␉␉␉p->size = size;␊ |
| 224 | ␉␉} else␊ |
| 225 | ␉␉␉return 0; // error: not enough memory␊ |
| 226 | ␉} else␊ |
| 227 | ␉␉p->size = size;␊ |
| 228 | ␉return 1;␊ |
| 229 | }␊ |
| 230 | ␊ |
| 231 | uint32_t vector8_resizev(vector8_t *p, size_t size, uint8_t value)␊ |
| 232 | {␉// resize and give all new elements the value␊ |
| 233 | ␉size_t oldsize = p->size, i;␊ |
| 234 | ␉if (!vector8_resize(p, size))␊ |
| 235 | ␉␉return 0;␊ |
| 236 | ␉for (i = oldsize; i < size; i++)␊ |
| 237 | ␉␉p->data[i] = value;␊ |
| 238 | ␉return 1;␊ |
| 239 | }␊ |
| 240 | ␊ |
| 241 | void vector8_init(vector8_t *p)␊ |
| 242 | {␊ |
| 243 | ␉p->data = NULL;␊ |
| 244 | ␉p->size = p->allocsize = 0;␊ |
| 245 | }␊ |
| 246 | ␊ |
| 247 | vector8_t *vector8_new(size_t size, uint8_t value)␊ |
| 248 | {␊ |
| 249 | ␉vector8_t *p = png_alloc_malloc(sizeof (vector8_t));␊ |
| 250 | ␉if(!p)␊ |
| 251 | ␉{␊ |
| 252 | ␉␉return NULL;␊ |
| 253 | ␉}␊ |
| 254 | ␉vector8_init(p);␊ |
| 255 | ␉if (size && !vector8_resizev(p, size, value))␊ |
| 256 | ␉{␊ |
| 257 | ␉␉vector8_cleanup(p);␊ |
| 258 | ␉␉png_alloc_free(p);␊ |
| 259 | ␉␉return NULL;␊ |
| 260 | ␉}␊ |
| 261 | ␉return p;␊ |
| 262 | }␊ |
| 263 | ␊ |
| 264 | vector8_t *vector8_copy(vector8_t *p)␊ |
| 265 | {␊ |
| 266 | ␉vector8_t *q = vector8_new(p->size, 0);␊ |
| 267 | ␉uint32_t n;␊ |
| 268 | ␉if (!q)␊ |
| 269 | ␉{␊ |
| 270 | ␉return NULL;␊ |
| 271 | ␉}␊ |
| 272 | ␉for (n = 0; n < q->size; n++)␊ |
| 273 | ␉␉q->data[n] = p->data[n];␊ |
| 274 | ␉return q;␊ |
| 275 | }␊ |
| 276 | ␊ |
| 277 | /*************************************************************************************************/␊ |
| 278 | ␊ |
| 279 | const uint32_t LENBASE[29] = { 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51,␊ |
| 280 | ␉59, 67, 83, 99, 115, 131, 163, 195, 227, 258 };␊ |
| 281 | const uint32_t LENEXTRA[29] = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4,␊ |
| 282 | ␉4, 5, 5, 5, 5, 0 };␊ |
| 283 | const uint32_t DISTBASE[30] = { 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385,␊ |
| 284 | ␉513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577 };␊ |
| 285 | const uint32_t DISTEXTRA[30] = { 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,␊ |
| 286 | ␉10, 10, 11, 11, 12, 12, 13, 13 };␊ |
| 287 | // code length code lengths␊ |
| 288 | const uint32_t CLCL[19] = { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };␊ |
| 289 | ␊ |
| 290 | /*************************************************************************************************/␊ |
| 291 | ␊ |
| 292 | typedef struct {␊ |
| 293 | ␉// 2D representation of a huffman tree: The one dimension is "0" or "1", the other contains all␊ |
| 294 | ␉// nodes and leaves of the tree.␊ |
| 295 | ␉vector32_t *tree2d;␊ |
| 296 | } HuffmanTree;␊ |
| 297 | ␊ |
| 298 | HuffmanTree *HuffmanTree_new()␊ |
| 299 | {␊ |
| 300 | ␉HuffmanTree *tree = png_alloc_malloc(sizeof (HuffmanTree));␊ |
| 301 | ␉if (!tree)␊ |
| 302 | ␉{␊ |
| 303 | ␉␉return NULL;␊ |
| 304 | ␉}␊ |
| 305 | ␉tree->tree2d = NULL;␊ |
| 306 | ␉return tree;␊ |
| 307 | }␊ |
| 308 | ␊ |
| 309 | int HuffmanTree_makeFromLengths(HuffmanTree *tree, const vector32_t *bitlen, uint32_t maxbitlen)␊ |
| 310 | {␉// make tree given the lengths␊ |
| 311 | ␉uint32_t bits, n, i;␊ |
| 312 | ␉uint32_t numcodes = (uint32_t) bitlen->size, treepos = 0, nodefilled = 0;␊ |
| 313 | ␉vector32_t *tree1d, *blcount, *nextcode;␊ |
| 314 | ␉tree1d = vector32_new(numcodes, 0);␊ |
| 315 | ␉blcount = vector32_new(maxbitlen + 1, 0);␊ |
| 316 | ␉nextcode = vector32_new(maxbitlen + 1, 0);␊ |
| 317 | ␉if (!tree1d || !blcount || !nextcode || !nextcode->data)␊ |
| 318 | ␉{␊ |
| 319 | ␉␉goto error;␊ |
| 320 | ␉}␊ |
| 321 | ␉for (bits = 0; bits < numcodes; bits++)␊ |
| 322 | ␉␉blcount->data[bitlen->data[bits]]++; // count number of instances of each code length␊ |
| 323 | ␉for (bits = 1; bits <= maxbitlen; bits++)␊ |
| 324 | ␉␉nextcode->data[bits] = (nextcode->data[bits - 1] + blcount->data[bits - 1]) << 1;␊ |
| 325 | ␉for (n = 0; n < numcodes; n++)␊ |
| 326 | ␉␉if (bitlen->data[n] != 0)␊ |
| 327 | ␉␉␉tree1d->data[n] = nextcode->data[bitlen->data[n]]++; // generate all the codes␊ |
| 328 | ␉// 0x7fff here means the tree2d isn't filled there yet␊ |
| 329 | ␉vector32_t *tree2d = vector32_new(numcodes * 2, 0x7fff);␊ |
| 330 | ␉tree->tree2d = tree2d;␊ |
| 331 | ␉for (n = 0; n < numcodes; n++) // the codes␊ |
| 332 | ␉␉for (i = 0; i < bitlen->data[n]; i++)␊ |
| 333 | ␉␉{ // the bits for this code␊ |
| 334 | ␉␉␉uint32_t bit = (tree1d->data[n] >> (bitlen->data[n] - i - 1)) & 1;␊ |
| 335 | ␉␉␉if (treepos > numcodes - 2)␊ |
| 336 | ␉␉␉␉return 55;␊ |
| 337 | ␉␉␉if (tree2d->data[2 * treepos + bit] == 0x7fff) // not yet filled in␊ |
| 338 | ␉␉␉{␊ |
| 339 | ␉␉␉␉if (i + 1 == bitlen->data[n]) // last bit␊ |
| 340 | ␉␉␉␉{␊ |
| 341 | ␉␉␉␉␉tree2d->data[2 * treepos + bit] = n;␊ |
| 342 | ␉␉␉␉␉treepos = 0;␊ |
| 343 | ␉␉␉␉}␊ |
| 344 | ␉␉␉␉else // addresses are encoded as values > numcodes␊ |
| 345 | ␉␉␉␉{␊ |
| 346 | ␉␉␉␉␉tree2d->data[2 * treepos + bit] = ++nodefilled + numcodes;␊ |
| 347 | ␉␉␉␉␉treepos = nodefilled;␊ |
| 348 | ␉␉␉␉}␊ |
| 349 | ␉␉␉} else // subtract numcodes from address to get address value␊ |
| 350 | ␉␉␉␉treepos = tree2d->data[2 * treepos + bit] - numcodes;␊ |
| 351 | ␉␉}␊ |
| 352 | ␉return 0;␊ |
| 353 | error:␊ |
| 354 | ␉if (tree1d)␊ |
| 355 | ␉{␊ |
| 356 | ␉␉vector32_cleanup(tree1d);␊ |
| 357 | ␉␉png_alloc_free(tree1d);␊ |
| 358 | ␉}␊ |
| 359 | ␉if (blcount)␊ |
| 360 | ␉{␊ |
| 361 | ␉␉vector32_cleanup(blcount);␊ |
| 362 | ␉␉png_alloc_free(blcount);␊ |
| 363 | ␉}␊ |
| 364 | ␉if (nextcode)␊ |
| 365 | ␉{␊ |
| 366 | ␉␉vector32_cleanup(nextcode);␊ |
| 367 | ␉␉png_alloc_free(nextcode);␊ |
| 368 | ␉}␊ |
| 369 | ␉return 1;␊ |
| 370 | }␊ |
| 371 | ␊ |
| 372 | int HuffmanTree_decode(const HuffmanTree *tree, bool *decoded, uint32_t *result, size_t *treepos,␊ |
| 373 | ␉␉uint32_t bit)␊ |
| 374 | {␉// Decodes a symbol from the tree␊ |
| 375 | ␉const vector32_t *tree2d = tree->tree2d;␊ |
| 376 | ␉uint32_t numcodes = (uint32_t) tree2d->size / 2;␊ |
| 377 | ␉if (*treepos >= numcodes)␊ |
| 378 | ␉␉return 11; // error: you appeared outside the codetree␊ |
| 379 | ␉*result = tree2d->data[2 * (*treepos) + bit];␊ |
| 380 | ␉*decoded = (*result < numcodes);␊ |
| 381 | ␉*treepos = *decoded ? 0 : *result - numcodes;␊ |
| 382 | ␉return 0;␊ |
| 383 | }␊ |
| 384 | ␊ |
| 385 | /*************************************************************************************************/␊ |
| 386 | ␊ |
| 387 | int Inflator_error;␊ |
| 388 | ␊ |
| 389 | uint32_t Zlib_readBitFromStream(size_t *bitp, const uint8_t *bits)␊ |
| 390 | {␊ |
| 391 | ␉uint32_t result = (bits[*bitp >> 3] >> (*bitp & 0x7)) & 1;␊ |
| 392 | ␉(*bitp)++;␊ |
| 393 | ␉return result;␊ |
| 394 | }␊ |
| 395 | ␊ |
| 396 | uint32_t Zlib_readBitsFromStream(size_t *bitp, const uint8_t *bits, size_t nbits)␊ |
| 397 | {␊ |
| 398 | ␉uint32_t i, result = 0;␊ |
| 399 | ␉for (i = 0; i < nbits; i++)␊ |
| 400 | ␉␉result += (Zlib_readBitFromStream(bitp, bits)) << i;␊ |
| 401 | ␉return result;␊ |
| 402 | }␊ |
| 403 | ␊ |
| 404 | void Inflator_generateFixedTrees(HuffmanTree *tree, HuffmanTree *treeD)␊ |
| 405 | {␉// get the tree of a deflated block with fixed tree␊ |
| 406 | ␉size_t i;␊ |
| 407 | ␉vector32_t *bitlen, *bitlenD;␊ |
| 408 | ␉bitlen = vector32_new(288, 8);␊ |
| 409 | ␉bitlenD = vector32_new(32, 5);␊ |
| 410 | ␉for (i = 144; i <= 255; i++)␊ |
| 411 | ␉␉bitlen->data[i] = 9;␊ |
| 412 | ␉for (i = 256; i <= 279; i++)␊ |
| 413 | ␉␉bitlen->data[i] = 7;␊ |
| 414 | ␉HuffmanTree_makeFromLengths(tree, bitlen, 15);␊ |
| 415 | ␉HuffmanTree_makeFromLengths(treeD, bitlenD, 15);␊ |
| 416 | }␊ |
| 417 | ␊ |
| 418 | uint32_t Inflator_huffmanDecodeSymbol(const uint8_t *in, size_t *bp, const HuffmanTree *codetree,␊ |
| 419 | ␉␉size_t inlength)␊ |
| 420 | {␉// decode a single symbol from given list of bits with given code tree. returns the symbol␊ |
| 421 | ␉bool decoded = false;␊ |
| 422 | ␉uint32_t ct = 0;␊ |
| 423 | ␉size_t treepos = 0;␊ |
| 424 | ␉for (;;) {␊ |
| 425 | ␉␉if ((*bp & 0x07) == 0 && (*bp >> 3) > inlength) {␊ |
| 426 | ␉␉␉Inflator_error = 10; // error: end reached without endcode␊ |
| 427 | ␉␉␉return 0;␊ |
| 428 | ␉␉}␊ |
| 429 | ␉␉Inflator_error = HuffmanTree_decode(codetree, &decoded, &ct, &treepos,␊ |
| 430 | ␉␉␉␉Zlib_readBitFromStream(bp, in));␊ |
| 431 | ␉␉if (Inflator_error)␊ |
| 432 | ␉␉␉return 0; // stop, an error happened␊ |
| 433 | ␉␉if (decoded)␊ |
| 434 | ␉␉␉return ct;␊ |
| 435 | ␉}␊ |
| 436 | }␊ |
| 437 | ␊ |
| 438 | void Inflator_getTreeInflateDynamic(HuffmanTree *tree, HuffmanTree *treeD, const uint8_t *in,␊ |
| 439 | ␉␉size_t *bp, size_t inlength)␊ |
| 440 | {␉// get the tree of a deflated block with dynamic tree, the tree itself is also Huffman␊ |
| 441 | ␉// compressed with a known tree␊ |
| 442 | ␉size_t i, n;␊ |
| 443 | ␉size_t HLIT;␊ |
| 444 | ␉size_t HDIST;␊ |
| 445 | ␉size_t HCLEN;␊ |
| 446 | ␉size_t replength;␊ |
| 447 | ␉vector32_t *codelengthcode;␊ |
| 448 | ␉HuffmanTree *codelengthcodetree = HuffmanTree_new(); // the code tree for code length codes␊ |
| 449 | ␉vector32_t *bitlen, *bitlenD;␊ |
| 450 | ␉bitlen = vector32_new(288, 0);␊ |
| 451 | ␉bitlenD = vector32_new(32, 0);␊ |
| 452 | ␉if (*bp >> 3 >= inlength - 2)␊ |
| 453 | ␉{␊ |
| 454 | ␉␉Inflator_error = 49; // the bit pointer is or will go past the memory␊ |
| 455 | ␉␉return;␊ |
| 456 | ␉}␊ |
| 457 | ␉HLIT = Zlib_readBitsFromStream(bp, in, 5) + 257;␉// number of literal/length codes + 257␊ |
| 458 | ␉HDIST = Zlib_readBitsFromStream(bp, in, 5) + 1;␉// number of dist codes + 1␊ |
| 459 | ␉HCLEN = Zlib_readBitsFromStream(bp, in, 4) + 4;␉// number of code length codes + 4␊ |
| 460 | ␉// lengths of tree to decode the lengths of the dynamic tree␊ |
| 461 | ␉codelengthcode = vector32_new(19, 0);␊ |
| 462 | ␉for (i = 0; i < 19; i++)␊ |
| 463 | ␉␉codelengthcode->data[CLCL[i]] = (i < HCLEN) ? Zlib_readBitsFromStream(bp, in, 3) : 0;␊ |
| 464 | ␉Inflator_error = HuffmanTree_makeFromLengths(codelengthcodetree, codelengthcode, 7);␊ |
| 465 | ␉if (Inflator_error)␊ |
| 466 | ␉␉return;␊ |
| 467 | ␉for (i = 0; i < HLIT + HDIST; )␊ |
| 468 | ␉{␊ |
| 469 | ␉␉uint32_t code = Inflator_huffmanDecodeSymbol(in, bp, codelengthcodetree, inlength);␊ |
| 470 | ␉␉if (Inflator_error)␊ |
| 471 | ␉␉{␊ |
| 472 | ␉␉␉return;␊ |
| 473 | ␉␉}␊ |
| 474 | ␉␉if (code <= 15) // a length code␊ |
| 475 | ␉␉{␊ |
| 476 | ␉␉␉if (i < HLIT)␊ |
| 477 | ␉␉␉{␊ |
| 478 | ␉␉␉␉bitlen->data[i++] = code;␊ |
| 479 | ␉␉␉}␊ |
| 480 | ␉␉␉else␊ |
| 481 | ␉␉␉{␊ |
| 482 | ␉␉␉␉bitlenD->data[i++ - HLIT] = code;␊ |
| 483 | ␉␉␉}␊ |
| 484 | ␉␉} else if (code == 16)␊ |
| 485 | ␉␉{ // repeat previous␊ |
| 486 | ␉␉␉uint32_t value; // set value to the previous code␊ |
| 487 | ␉␉␉if (*bp >> 3 >= inlength)␊ |
| 488 | ␉␉␉{␊ |
| 489 | ␉␉␉␉Inflator_error = 50; // error, bit pointer jumps past memory␊ |
| 490 | ␉␉␉␉return;␊ |
| 491 | ␉␉␉}␊ |
| 492 | ␉␉␉replength = 3 + Zlib_readBitsFromStream(bp, in, 2);␊ |
| 493 | ␊ |
| 494 | ␉␉␉if ((i - 1) < HLIT)␊ |
| 495 | ␉␉␉␉value = bitlen->data[i - 1];␊ |
| 496 | ␉␉␉else␊ |
| 497 | ␉␉␉␉value = bitlenD->data[i - HLIT - 1];␊ |
| 498 | ␉␉␉for (n = 0; n < replength; n++)␊ |
| 499 | ␉␉␉{ // repeat this value in the next lengths␊ |
| 500 | ␉␉␉␉if (i >= HLIT + HDIST)␊ |
| 501 | ␉␉␉␉{␊ |
| 502 | ␉␉␉␉␉Inflator_error = 13; // error: i is larger than the amount of codes␊ |
| 503 | ␉␉␉␉␉return;␊ |
| 504 | ␉␉␉␉}␊ |
| 505 | ␉␉␉␉if (i < HLIT)␊ |
| 506 | ␉␉␉␉␉bitlen->data[i++] = value;␊ |
| 507 | ␉␉␉␉else␊ |
| 508 | ␉␉␉␉␉bitlenD->data[i++ - HLIT] = value;␊ |
| 509 | ␉␉␉}␊ |
| 510 | ␉␉}␊ |
| 511 | ␉␉else if (code == 17)␊ |
| 512 | ␉␉{ // repeat "0" 3-10 times␊ |
| 513 | ␉␉␉if (*bp >> 3 >= inlength)␊ |
| 514 | ␉␉␉{␊ |
| 515 | ␉␉␉␉Inflator_error = 50; // error, bit pointer jumps past memory␊ |
| 516 | ␉␉␉␉return;␊ |
| 517 | ␉␉␉}␊ |
| 518 | ␉␉␉replength = 3 + Zlib_readBitsFromStream(bp, in, 3);␊ |
| 519 | ␉␉␉for (n = 0; n < replength; n++)␊ |
| 520 | ␉␉␉{ // repeat this value in the next lengths␊ |
| 521 | ␉␉␉␉if (i >= HLIT + HDIST) {␊ |
| 522 | ␉␉␉␉␉Inflator_error = 14; // error: i is larger than the amount of codes␊ |
| 523 | ␉␉␉␉␉return;␊ |
| 524 | ␉␉␉␉}␊ |
| 525 | ␉␉␉␉if (i < HLIT)␊ |
| 526 | ␉␉␉␉{␊ |
| 527 | ␉␉␉␉␉bitlen->data[i++] = 0;␊ |
| 528 | ␉␉␉␉}␊ |
| 529 | ␉␉␉␉else␊ |
| 530 | ␉␉␉␉{␊ |
| 531 | ␉␉␉␉␉bitlenD->data[i++ - HLIT] = 0;␊ |
| 532 | ␉␉␉␉}␊ |
| 533 | ␉␉␉}␊ |
| 534 | ␉␉}␊ |
| 535 | ␉␉else if (code == 18)␊ |
| 536 | ␉␉{ // repeat "0" 11-138 times␊ |
| 537 | ␉␉␉if (*bp >> 3 >= inlength)␊ |
| 538 | ␉␉␉{␊ |
| 539 | ␉␉␉␉Inflator_error = 50; // error, bit pointer jumps past memory␊ |
| 540 | ␉␉␉␉return;␊ |
| 541 | ␉␉␉}␊ |
| 542 | ␉␉␉replength = 11 + Zlib_readBitsFromStream(bp, in, 7);␊ |
| 543 | ␉␉␉for (n = 0; n < replength; n++)␊ |
| 544 | ␉␉␉{ // repeat this value in the next lengths␊ |
| 545 | ␉␉␉␉if (i >= HLIT + HDIST)␊ |
| 546 | ␉␉␉␉{␊ |
| 547 | ␉␉␉␉␉Inflator_error = 15; // error: i is larger than the amount of codes␊ |
| 548 | ␉␉␉␉␉return;␊ |
| 549 | ␉␉␉␉}␊ |
| 550 | ␉␉␉␉if (i < HLIT)␊ |
| 551 | ␉␉␉␉{␊ |
| 552 | ␉␉␉␉␉bitlen->data[i++] = 0;␊ |
| 553 | ␉␉␉␉}␊ |
| 554 | ␉␉␉␉else␊ |
| 555 | ␉␉␉␉{␊ |
| 556 | ␉␉␉␉␉bitlenD->data[i++ - HLIT] = 0;␊ |
| 557 | ␉␉␉␉}␊ |
| 558 | ␉␉␉}␊ |
| 559 | ␉␉}␊ |
| 560 | ␉␉else␊ |
| 561 | ␉␉{␊ |
| 562 | ␉␉␉Inflator_error = 16; // error: an nonexitent code appeared. This can never happen.␊ |
| 563 | ␉␉␉return;␊ |
| 564 | ␉␉}␊ |
| 565 | ␉}␊ |
| 566 | ␉if (bitlen->data[256] == 0)␊ |
| 567 | ␉{␊ |
| 568 | ␉␉Inflator_error = 64; // the length of the end code 256 must be larger than 0␊ |
| 569 | ␉␉return;␊ |
| 570 | ␉}␊ |
| 571 | ␉// now we've finally got HLIT and HDIST, so generate the code trees, and the function is done␊ |
| 572 | ␉Inflator_error = HuffmanTree_makeFromLengths(tree, bitlen, 15);␊ |
| 573 | ␉if (Inflator_error)␊ |
| 574 | ␉␉return;␊ |
| 575 | ␉Inflator_error = HuffmanTree_makeFromLengths(treeD, bitlenD, 15);␊ |
| 576 | ␉if (Inflator_error)␊ |
| 577 | ␉␉return;␊ |
| 578 | }␊ |
| 579 | ␊ |
| 580 | void Inflator_inflateHuffmanBlock(vector8_t *out, const uint8_t *in, size_t *bp, size_t *pos,␊ |
| 581 | ␉␉size_t inlength, uint32_t btype)␊ |
| 582 | {␊ |
| 583 | ␉HuffmanTree *codetree, *codetreeD; // the code tree for Huffman codes, dist codes␊ |
| 584 | ␉codetree = HuffmanTree_new();␊ |
| 585 | ␉codetreeD = HuffmanTree_new();␊ |
| 586 | ␉if (btype == 1)␊ |
| 587 | ␉␉Inflator_generateFixedTrees(codetree, codetreeD);␊ |
| 588 | ␉else if (btype == 2)␊ |
| 589 | ␉{␊ |
| 590 | ␉␉Inflator_getTreeInflateDynamic(codetree, codetreeD, in, bp, inlength);␊ |
| 591 | ␉␉if (Inflator_error)␊ |
| 592 | ␉␉␉return;␊ |
| 593 | ␉}␊ |
| 594 | ␉for (;;)␊ |
| 595 | ␉{␊ |
| 596 | ␉␉uint32_t code = Inflator_huffmanDecodeSymbol(in, bp, codetree, inlength);␊ |
| 597 | ␉␉if (Inflator_error)␊ |
| 598 | ␉␉␉return;␊ |
| 599 | ␉␉if (code == 256) // end code␊ |
| 600 | ␉␉{␊ |
| 601 | ␉␉␉return;␊ |
| 602 | ␉␉}␊ |
| 603 | ␉␉else if (code <= 255) { // literal symbol␊ |
| 604 | ␉␉␉if (*pos >= out->size)␊ |
| 605 | ␉␉␉{␊ |
| 606 | ␉␉␉␉vector8_resize(out, (*pos + 1) * 2); // reserve more room␊ |
| 607 | ␉␉␉}␊ |
| 608 | ␉␉␉out->data[(*pos)++] = (uint8_t) code;␊ |
| 609 | ␉␉} else if (code >= 257 && code <= 285)␊ |
| 610 | ␉␉{ // length code␊ |
| 611 | ␉␉␉size_t length = LENBASE[code - 257], numextrabits = LENEXTRA[code - 257];␊ |
| 612 | ␉␉␉if ((*bp >> 3) >= inlength)␊ |
| 613 | ␉␉␉{␊ |
| 614 | ␉␉␉␉Inflator_error = 51; // error, bit pointer will jump past memory␊ |
| 615 | ␉␉␉␉return;␊ |
| 616 | ␉␉␉}␊ |
| 617 | ␉␉␉length += Zlib_readBitsFromStream(bp, in, numextrabits);␊ |
| 618 | ␉␉␉uint32_t codeD = Inflator_huffmanDecodeSymbol(in, bp, codetreeD, inlength);␊ |
| 619 | ␉␉␉if (Inflator_error)␊ |
| 620 | ␉␉␉␉return;␊ |
| 621 | ␉␉␉if (codeD > 29) {␊ |
| 622 | ␉␉␉␉Inflator_error = 18; // error: invalid dist code (30-31 are never used)␊ |
| 623 | ␉␉␉␉return;␊ |
| 624 | ␉␉␉}␊ |
| 625 | ␉␉␉uint32_t dist = DISTBASE[codeD], numextrabitsD = DISTEXTRA[codeD];␊ |
| 626 | ␉␉␉if ((*bp >> 3) >= inlength) {␊ |
| 627 | ␉␉␉␉Inflator_error = 51; // error, bit pointer will jump past memory␊ |
| 628 | ␉␉␉␉return;␊ |
| 629 | ␉␉␉}␊ |
| 630 | ␉␉␉dist += Zlib_readBitsFromStream(bp, in, numextrabitsD);␊ |
| 631 | ␉␉␉size_t start = *pos, back = start - dist; // backwards␊ |
| 632 | ␉␉␉if (*pos + length >= out->size)␊ |
| 633 | ␉␉␉␉vector8_resize(out, (*pos + length) * 2); // reserve more room␊ |
| 634 | ␉␉␉size_t i;␊ |
| 635 | ␉␉␉for (i = 0; i < length; i++) {␊ |
| 636 | ␉␉␉␉out->data[(*pos)++] = out->data[back++];␊ |
| 637 | ␉␉␉␉if (back >= start)␊ |
| 638 | ␉␉␉␉␉back = start - dist;␊ |
| 639 | ␉␉␉}␊ |
| 640 | ␉␉}␊ |
| 641 | ␉}␊ |
| 642 | }␊ |
| 643 | ␊ |
| 644 | void Inflator_inflateNoCompression(vector8_t *out, const uint8_t *in, size_t *bp, size_t *pos,␊ |
| 645 | ␉␉size_t inlength)␊ |
| 646 | {␊ |
| 647 | ␉while ((*bp & 0x7) != 0)␊ |
| 648 | ␉␉(*bp)++; // go to first boundary of byte␊ |
| 649 | ␉size_t p = *bp / 8;␊ |
| 650 | ␉if (p >= inlength - 4) {␊ |
| 651 | ␉␉Inflator_error = 52; // error, bit pointer will jump past memory␊ |
| 652 | ␉␉return;␊ |
| 653 | ␉}␊ |
| 654 | ␉uint32_t LEN = in[p] + 256 * in[p + 1], NLEN = in[p + 2] + 256 * in[p + 3];␊ |
| 655 | ␉p += 4;␊ |
| 656 | ␉if (LEN + NLEN != 65535) {␊ |
| 657 | ␉␉Inflator_error = 21; // error: NLEN is not one's complement of LEN␊ |
| 658 | ␉␉return;␊ |
| 659 | ␉}␊ |
| 660 | ␉if (*pos + LEN >= out->size)␊ |
| 661 | ␉␉vector8_resize(out, *pos + LEN);␊ |
| 662 | ␉if (p + LEN > inlength) {␊ |
| 663 | ␉␉Inflator_error = 23; // error: reading outside of in buffer␊ |
| 664 | ␉␉return;␊ |
| 665 | ␉}␊ |
| 666 | ␉uint32_t n;␊ |
| 667 | ␉for (n = 0; n < LEN; n++)␊ |
| 668 | ␉␉out->data[(*pos)++] = in[p++]; // read LEN bytes of literal data␊ |
| 669 | ␉*bp = p * 8;␊ |
| 670 | }␊ |
| 671 | ␊ |
| 672 | void Inflator_inflate(vector8_t *out, const vector8_t *in, size_t inpos)␊ |
| 673 | {␊ |
| 674 | ␉size_t bp = 0, pos = 0; // bit pointer and byte pointer␊ |
| 675 | ␉Inflator_error = 0;␊ |
| 676 | ␉uint32_t BFINAL = 0;␊ |
| 677 | ␉while (!BFINAL && !Inflator_error) {␊ |
| 678 | ␉␉if (bp >> 3 >= in->size) {␊ |
| 679 | ␉␉␉Inflator_error = 52; // error, bit pointer will jump past memory␊ |
| 680 | ␉␉␉return;␊ |
| 681 | ␉␉}␊ |
| 682 | ␉␉BFINAL = Zlib_readBitFromStream(&bp, &in->data[inpos]);␊ |
| 683 | ␉␉uint32_t BTYPE = Zlib_readBitFromStream(&bp, &in->data[inpos]);␊ |
| 684 | ␉␉BTYPE += 2 * Zlib_readBitFromStream(&bp, &in->data[inpos]);␊ |
| 685 | ␉␉if (BTYPE == 3) {␊ |
| 686 | ␉␉␉Inflator_error = 20; // error: invalid BTYPE␊ |
| 687 | ␉␉␉return;␊ |
| 688 | ␉␉}␊ |
| 689 | ␉␉else if (BTYPE == 0)␊ |
| 690 | ␉␉␉Inflator_inflateNoCompression(out, &in->data[inpos], &bp, &pos, in->size);␊ |
| 691 | ␉␉else␊ |
| 692 | ␉␉␉Inflator_inflateHuffmanBlock(out, &in->data[inpos], &bp, &pos, in->size, BTYPE);␊ |
| 693 | ␉}␊ |
| 694 | ␉if (!Inflator_error)␊ |
| 695 | ␉␉vector8_resize(out, pos); // Only now we know the true size of out, resize it to that␊ |
| 696 | }␊ |
| 697 | ␊ |
| 698 | /*************************************************************************************************/␊ |
| 699 | ␊ |
| 700 | int Zlib_decompress(vector8_t *out, const vector8_t *in) // returns error value␊ |
| 701 | {␊ |
| 702 | ␉if (in->size < 2)␊ |
| 703 | ␉␉return 53; // error, size of zlib data too small␊ |
| 704 | ␉if ((in->data[0] * 256 + in->data[1]) % 31 != 0)␊ |
| 705 | ␉␉// error: 256 * in->data[0] + in->data[1] must be a multiple of 31, the FCHECK value is␊ |
| 706 | ␉␉// supposed to be made that way␊ |
| 707 | ␉␉return 24;␊ |
| 708 | ␉uint32_t CM = in->data[0] & 15, CINFO = (in->data[0] >> 4) & 15, FDICT = (in->data[1] >> 5) & 1;␊ |
| 709 | ␉if (CM != 8 || CINFO > 7){␊ |
| 710 | ␉␉// error: only compression method 8: inflate with sliding window of 32k is supported by␊ |
| 711 | ␉␉// the PNG spec␊ |
| 712 | ␊ |
| 713 | ␉␉return 25;␊ |
| 714 | ␉}␊ |
| 715 | ␉if (FDICT != 0){␊ |
| 716 | ␉␉// error: the specification of PNG says about the zlib stream: "The additional flags shall␊ |
| 717 | ␉␉// not specify a preset dictionary."␊ |
| 718 | ␉␉return 26;␊ |
| 719 | ␉}␊ |
| 720 | ␉Inflator_inflate(out, in, 2);␊ |
| 721 | ␉return Inflator_error; // note: adler32 checksum was skipped and ignored␊ |
| 722 | }␊ |
| 723 | ␊ |
| 724 | /*************************************************************************************************/␊ |
| 725 | ␊ |
| 726 | #define PNG_SIGNATURE␉0x0a1a0a0d474e5089ull␊ |
| 727 | ␊ |
| 728 | #define CHUNK_IHDR␉␉0x52444849␊ |
| 729 | #define CHUNK_IDAT␉␉0x54414449␊ |
| 730 | #define CHUNK_IEND␉␉0x444e4549␊ |
| 731 | #define CHUNK_PLTE␉␉0x45544c50␊ |
| 732 | #define CHUNK_tRNS␉␉0x534e5274␊ |
| 733 | ␊ |
| 734 | int PNG_error;␊ |
| 735 | ␊ |
| 736 | uint32_t PNG_readBitFromReversedStream(size_t *bitp, const uint8_t *bits)␊ |
| 737 | {␊ |
| 738 | ␉uint32_t result = (bits[*bitp >> 3] >> (7 - (*bitp & 0x7))) & 1;␊ |
| 739 | ␉(*bitp)++;␊ |
| 740 | ␉return result;␊ |
| 741 | }␊ |
| 742 | ␊ |
| 743 | uint32_t PNG_readBitsFromReversedStream(size_t *bitp, const uint8_t *bits, uint32_t nbits)␊ |
| 744 | {␊ |
| 745 | ␉uint32_t i, result = 0;␊ |
| 746 | ␉for (i = nbits - 1; i < nbits; i--)␊ |
| 747 | ␉␉result += ((PNG_readBitFromReversedStream(bitp, bits)) << i);␊ |
| 748 | ␉return result;␊ |
| 749 | }␊ |
| 750 | ␊ |
| 751 | void PNG_setBitOfReversedStream(size_t *bitp, uint8_t *bits, uint32_t bit)␊ |
| 752 | {␊ |
| 753 | ␉bits[*bitp >> 3] |= (bit << (7 - (*bitp & 0x7)));␊ |
| 754 | ␉(*bitp)++;␊ |
| 755 | }␊ |
| 756 | ␊ |
| 757 | uint32_t PNG_read32bitInt(const uint8_t *buffer)␊ |
| 758 | {␊ |
| 759 | ␉return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];␊ |
| 760 | }␊ |
| 761 | ␊ |
| 762 | int PNG_checkColorValidity(uint32_t colorType, uint32_t bd) // return type is a LodePNG error code␊ |
| 763 | {␊ |
| 764 | ␉if ((colorType == 2 || colorType == 4 || colorType == 6)) {␊ |
| 765 | ␉␉if (!(bd == 8 || bd == 16))␊ |
| 766 | ␉␉␉return 37;␊ |
| 767 | ␉␉else␊ |
| 768 | ␉␉␉return 0;␊ |
| 769 | ␉} else if (colorType == 0) {␊ |
| 770 | ␉␉if (!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16))␊ |
| 771 | ␉␉␉return 37;␊ |
| 772 | ␉␉else␊ |
| 773 | ␉␉␉return 0;␊ |
| 774 | ␉} else if (colorType == 3) {␊ |
| 775 | ␉␉if (!(bd == 1 || bd == 2 || bd == 4 || bd == 8))␊ |
| 776 | ␉␉␉return 37;␊ |
| 777 | ␉␉else␊ |
| 778 | ␉␉␉return 0;␊ |
| 779 | ␉} else␊ |
| 780 | ␉␉return 31; // nonexistent color type␊ |
| 781 | }␊ |
| 782 | ␊ |
| 783 | uint32_t PNG_getBpp(const PNG_info_t *info)␊ |
| 784 | {␊ |
| 785 | ␉uint32_t bitDepth, colorType;␊ |
| 786 | ␉bitDepth = info->bitDepth;␊ |
| 787 | ␉colorType = info->colorType;␊ |
| 788 | ␉if (colorType == 2)␊ |
| 789 | ␉{␊ |
| 790 | ␉␉return (3 * bitDepth);␊ |
| 791 | ␉}␊ |
| 792 | ␉else if (colorType >= 4)␊ |
| 793 | ␉{␊ |
| 794 | ␉␉return (colorType - 2) * bitDepth;␊ |
| 795 | ␉}␊ |
| 796 | ␉else␊ |
| 797 | ␉{␊ |
| 798 | ␉␉return bitDepth;␊ |
| 799 | ␉}␊ |
| 800 | }␊ |
| 801 | ␊ |
| 802 | void PNG_readPngHeader(PNG_info_t *info, const uint8_t *in, size_t inlength)␊ |
| 803 | {␉// read the information from the header and store it in the Info␊ |
| 804 | ␉if (inlength < 29) {␊ |
| 805 | ␉␉PNG_error = 27; // error: the data length is smaller than the length of the header␊ |
| 806 | ␉␉return;␊ |
| 807 | ␉}␊ |
| 808 | ␉if (*(uint64_t *) in != PNG_SIGNATURE) {␊ |
| 809 | ␉␉PNG_error = 28; // no PNG signature␊ |
| 810 | ␉␉return;␊ |
| 811 | ␉}␊ |
| 812 | ␉if (*(uint32_t *) &in[12] != CHUNK_IHDR) {␊ |
| 813 | ␉␉PNG_error = 29; // error: it doesn't start with a IHDR chunk!␊ |
| 814 | ␉␉return;␊ |
| 815 | ␉}␊ |
| 816 | ␉info->width = PNG_read32bitInt(&in[16]);␊ |
| 817 | ␉info->height = PNG_read32bitInt(&in[20]);␊ |
| 818 | ␉info->bitDepth = in[24];␊ |
| 819 | ␉info->colorType = in[25];␊ |
| 820 | ␉info->compressionMethod = in[26];␊ |
| 821 | ␉if (in[26] != 0) {␊ |
| 822 | ␉␉PNG_error = 32; // error: only compression method 0 is allowed in the specification␊ |
| 823 | ␉␉return;␊ |
| 824 | ␉}␊ |
| 825 | ␉info->filterMethod = in[27];␊ |
| 826 | ␉if (in[27] != 0) {␊ |
| 827 | ␉␉PNG_error = 33; // error: only filter method 0 is allowed in the specification␊ |
| 828 | ␉␉return;␊ |
| 829 | ␉}␊ |
| 830 | ␉info->interlaceMethod = in[28];␊ |
| 831 | ␉if (in[28] > 1) {␊ |
| 832 | ␉␉PNG_error = 34; // error: only interlace methods 0 and 1 exist in the specification␊ |
| 833 | ␉␉return;␊ |
| 834 | ␉}␊ |
| 835 | ␉PNG_error = PNG_checkColorValidity(info->colorType, info->bitDepth);␊ |
| 836 | }␊ |
| 837 | ␊ |
| 838 | int PNG_paethPredictor(int a, int b, int c) // Paeth predicter, used by PNG filter type 4␊ |
| 839 | {␊ |
| 840 | ␉int p, pa, pb, pc;␊ |
| 841 | ␉p = a + b - c;␊ |
| 842 | ␉pa = p > a ? (p - a) : (a - p);␊ |
| 843 | ␉pb = p > b ? (p - b) : (b - p);␊ |
| 844 | ␉pc = p > c ? (p - c) : (c - p);␊ |
| 845 | ␉return (pa <= pb && pa <= pc) ? a : (pb <= pc ? b : c);␊ |
| 846 | }␊ |
| 847 | ␊ |
| 848 | void PNG_unFilterScanline(uint8_t *recon, const uint8_t *scanline, const uint8_t *precon,␊ |
| 849 | ␉␉size_t bytewidth, uint32_t filterType, size_t length)␊ |
| 850 | {␊ |
| 851 | ␉size_t i;␊ |
| 852 | ␉switch (filterType) {␊ |
| 853 | ␉case 0:␊ |
| 854 | ␉␉for (i = 0; i < length; i++)␊ |
| 855 | ␉␉␉recon[i] = scanline[i];␊ |
| 856 | ␉␉break;␊ |
| 857 | ␉case 1:␊ |
| 858 | ␉␉for (i = 0; i < bytewidth; i++)␊ |
| 859 | ␉␉␉recon[i] = scanline[i];␊ |
| 860 | ␉␉for (i = bytewidth; i < length; i++)␊ |
| 861 | ␉␉␉recon[i] = scanline[i] + recon[i - bytewidth];␊ |
| 862 | ␉␉break;␊ |
| 863 | ␉case 2:␊ |
| 864 | ␉␉if (precon)␊ |
| 865 | ␉␉␉for (i = 0; i < length; i++)␊ |
| 866 | ␉␉␉␉recon[i] = scanline[i] + precon[i];␊ |
| 867 | ␉␉else␊ |
| 868 | ␉␉␉for (i = 0; i < length; i++)␊ |
| 869 | ␉␉␉␉recon[i] = scanline[i];␊ |
| 870 | ␉␉break;␊ |
| 871 | ␉case 3:␊ |
| 872 | ␉␉if (precon) {␊ |
| 873 | ␉␉␉for (i = 0; i < bytewidth; i++)␊ |
| 874 | ␉␉␉␉recon[i] = scanline[i] + precon[i] / 2;␊ |
| 875 | ␉␉␉for (i = bytewidth; i < length; i++)␊ |
| 876 | ␉␉␉␉recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2);␊ |
| 877 | ␉␉} else {␊ |
| 878 | ␉␉␉for (i = 0; i < bytewidth; i++)␊ |
| 879 | ␉␉␉␉recon[i] = scanline[i];␊ |
| 880 | ␉␉␉for (i = bytewidth; i < length; i++)␊ |
| 881 | ␉␉␉␉recon[i] = scanline[i] + recon[i - bytewidth] / 2;␊ |
| 882 | ␉␉}␊ |
| 883 | ␉␉break;␊ |
| 884 | ␉case 4:␊ |
| 885 | ␉␉if (precon) {␊ |
| 886 | ␉␉␉for (i = 0; i < bytewidth; i++)␊ |
| 887 | ␉␉␉␉recon[i] = (uint8_t) (scanline[i] + PNG_paethPredictor(0, precon[i], 0));␊ |
| 888 | ␉␉␉for (i = bytewidth; i < length; i++)␊ |
| 889 | ␉␉␉␉recon[i] = (uint8_t) (scanline[i] + PNG_paethPredictor(recon[i - bytewidth],␊ |
| 890 | ␉␉␉␉␉␉precon[i], precon[i - bytewidth]));␊ |
| 891 | ␉␉} else {␊ |
| 892 | ␉␉␉for (i = 0; i < bytewidth; i++)␊ |
| 893 | ␉␉␉␉recon[i] = scanline[i];␊ |
| 894 | ␉␉␉for (i = bytewidth; i < length; i++)␊ |
| 895 | ␉␉␉␉recon[i] = (uint8_t) (scanline[i] + PNG_paethPredictor(recon[i - bytewidth], 0, 0));␊ |
| 896 | ␉␉}␊ |
| 897 | ␉␉break;␊ |
| 898 | ␉default:␊ |
| 899 | ␉␉PNG_error = 36; // error: nonexistent filter type given␊ |
| 900 | ␉␉return;␊ |
| 901 | ␉}␊ |
| 902 | }␊ |
| 903 | ␊ |
| 904 | void PNG_adam7Pass(uint8_t *out, uint8_t *linen, uint8_t *lineo, const uint8_t *in, uint32_t w,␊ |
| 905 | ␉␉size_t passleft, size_t passtop, size_t spacex, size_t spacey, size_t passw, size_t passh,␊ |
| 906 | ␉␉uint32_t bpp)␊ |
| 907 | {␉// filter and reposition the pixels into the output when the image is Adam7 interlaced. This␊ |
| 908 | ␉// function can only do it after the full image is already decoded. The out buffer must have␊ |
| 909 | ␉// the correct allocated memory size already.␊ |
| 910 | ␉if (passw == 0)␊ |
| 911 | ␉␉return;␊ |
| 912 | ␉size_t bytewidth = (bpp + 7) / 8, linelength = 1 + ((bpp * passw + 7) / 8);␊ |
| 913 | ␉uint32_t y;␊ |
| 914 | ␉for (y = 0; y < passh; y++) {␊ |
| 915 | ␉␉size_t i, b;␊ |
| 916 | ␉␉uint8_t filterType = in[y * linelength], *prevline = (y == 0) ? 0 : lineo;␊ |
| 917 | ␉␉PNG_unFilterScanline(linen, &in[y * linelength + 1], prevline, bytewidth, filterType,␊ |
| 918 | ␉␉␉␉(w * bpp + 7) / 8);␊ |
| 919 | ␉␉if (PNG_error)␊ |
| 920 | ␉␉␉return;␊ |
| 921 | ␉␉if (bpp >= 8)␊ |
| 922 | ␉␉␉for (i = 0; i < passw; i++)␊ |
| 923 | ␉␉␉␉for (b = 0; b < bytewidth; b++) // b = current byte of this pixel␊ |
| 924 | ␉␉␉␉␉out[bytewidth * w * (passtop + spacey * y) + bytewidth *␊ |
| 925 | ␉␉␉␉␉␉␉(passleft + spacex * i) + b] = linen[bytewidth * i + b];␊ |
| 926 | ␉␉else␊ |
| 927 | ␉␉␉for (i = 0; i < passw; i++)␊ |
| 928 | ␉␉␉{␊ |
| 929 | ␉␉␉␉size_t obp, bp;␊ |
| 930 | ␉␉␉␉obp = bpp * w * (passtop + spacey * y) + bpp * (passleft + spacex * i);␊ |
| 931 | ␉␉␉␉bp = i * bpp;␊ |
| 932 | ␉␉␉␉for (b = 0; b < bpp; b++)␊ |
| 933 | ␉␉␉␉␉PNG_setBitOfReversedStream(&obp, out, PNG_readBitFromReversedStream(&bp, linen));␊ |
| 934 | ␉␉␉}␊ |
| 935 | ␉␉uint8_t *temp = linen;␊ |
| 936 | ␉␉linen = lineo;␊ |
| 937 | ␉␉lineo = temp; // swap the two buffer pointers "line old" and "line new"␊ |
| 938 | ␉}␊ |
| 939 | }␊ |
| 940 | ␊ |
| 941 | int PNG_convert(const PNG_info_t *info, vector8_t *out, const uint8_t *in)␊ |
| 942 | {␉// converts from any color type to 32-bit. return value = LodePNG error code␊ |
| 943 | ␉size_t i, c;␊ |
| 944 | ␉uint32_t bitDepth, colorType;␊ |
| 945 | ␉bitDepth = info->bitDepth;␊ |
| 946 | ␉colorType = info->colorType;␊ |
| 947 | ␉size_t numpixels = info->width * info->height, bp = 0;␊ |
| 948 | ␉vector8_resize(out, numpixels * 4);␊ |
| 949 | ␉uint8_t *out_data = out->size ? out->data : 0;␊ |
| 950 | ␉if (bitDepth == 8 && colorType == 0) // greyscale␊ |
| 951 | ␉␉for (i = 0; i < numpixels; i++)␊ |
| 952 | ␉␉{␊ |
| 953 | ␉␉␉out_data[4 * i + 0] = out_data[4 * i + 1] = out_data[4 * i + 2] = in[i];␊ |
| 954 | ␉␉␉out_data[4 * i + 3] = (info->key_defined && (in[i] == info->key_r)) ? 0 : 255;␊ |
| 955 | ␉␉}␊ |
| 956 | ␉else if (bitDepth == 8 && colorType == 2) // RGB color␊ |
| 957 | ␉␉for (i = 0; i < numpixels; i++)␊ |
| 958 | ␉␉{␊ |
| 959 | ␉␉␉for (c = 0; c < 3; c++)␊ |
| 960 | ␉␉␉␉out_data[4 * i + c] = in[3 * i + c];␊ |
| 961 | ␉␉␉out_data[4 * i + 3] = (info->key_defined && (in[3 * i + 0] == info->key_r) &&␊ |
| 962 | ␉␉␉␉␉(in[3 * i + 1] == info->key_g) && (in[3 * i + 2] == info->key_b)) ? 0 : 255;␊ |
| 963 | ␉␉}␊ |
| 964 | ␉else if (bitDepth == 8 && colorType == 3) // indexed color (palette)␊ |
| 965 | ␉␉for (i = 0; i < numpixels; i++)␊ |
| 966 | ␉␉{␊ |
| 967 | ␉␉␉if (4U * in[i] >= info->palette->size)␊ |
| 968 | ␉␉␉␉return 46;␊ |
| 969 | ␉␉␉for (c = 0; c < 4; c++) // get rgb colors from the palette␊ |
| 970 | ␉␉␉␉out_data[4 * i + c] = info->palette->data[4 * in[i] + c];␊ |
| 971 | ␉␉}␊ |
| 972 | ␉else if (bitDepth == 8 && colorType == 4) // greyscale with alpha␊ |
| 973 | ␉␉for (i = 0; i < numpixels; i++) {␊ |
| 974 | ␉␉␉out_data[4 * i + 0] = out_data[4 * i + 1] = out_data[4 * i + 2] = in[2 * i + 0];␊ |
| 975 | ␉␉␉out_data[4 * i + 3] = in[2 * i + 1];␊ |
| 976 | ␉␉}␊ |
| 977 | ␉else if (bitDepth == 8 && colorType == 6)␊ |
| 978 | ␉␉for (i = 0; i < numpixels; i++)␊ |
| 979 | ␉␉␉for (c = 0; c < 4; c++)␊ |
| 980 | ␉␉␉␉out_data[4 * i + c] = in[4 * i + c]; // RGB with alpha␊ |
| 981 | ␉else if (bitDepth == 16 && colorType == 0) // greyscale␊ |
| 982 | ␉␉for (i = 0; i < numpixels; i++) {␊ |
| 983 | ␉␉␉out_data[4 * i + 0] = out_data[4 * i + 1] = out_data[4 * i + 2] = in[2 * i];␊ |
| 984 | ␉␉␉out_data[4 * i + 3] = (info->key_defined && (256U * in[i] + in[i + 1] == info->key_r))␊ |
| 985 | ␉␉␉␉␉? 0 : 255;␊ |
| 986 | ␉␉}␊ |
| 987 | ␉else if (bitDepth == 16 && colorType == 2) // RGB color␊ |
| 988 | ␉␉for (i = 0; i < numpixels; i++) {␊ |
| 989 | ␉␉␉for (c = 0; c < 3; c++)␊ |
| 990 | ␉␉␉␉out_data[4 * i + c] = in[6 * i + 2 * c];␊ |
| 991 | ␉␉␉out_data[4 * i + 3] = (info->key_defined &&␊ |
| 992 | ␉␉␉␉␉(256U * in[6 * i + 0] + in[6 * i + 1] == info->key_r) &&␊ |
| 993 | ␉␉␉␉␉(256U * in[6 * i + 2] + in[6 * i + 3] == info->key_g) &&␊ |
| 994 | ␉␉␉␉␉(256U * in[6 * i + 4] + in[6 * i + 5] == info->key_b)) ? 0 : 255;␊ |
| 995 | ␉␉}␊ |
| 996 | ␉else if (bitDepth == 16 && colorType == 4) // greyscale with alpha␊ |
| 997 | ␉␉for (i = 0; i < numpixels; i++) {␊ |
| 998 | ␉␉␉out_data[4 * i + 0] = out_data[4 * i + 1] = out_data[4 * i + 2] = in[4 * i]; // msb␊ |
| 999 | ␉␉␉out_data[4 * i + 3] = in[4 * i + 2];␊ |
| 1000 | ␉␉}␊ |
| 1001 | ␉else if (bitDepth == 16 && colorType == 6)␊ |
| 1002 | ␉␉for (i = 0; i < numpixels; i++)␊ |
| 1003 | ␉␉␉for (c = 0; c < 4; c++)␊ |
| 1004 | ␉␉␉␉out_data[4 * i + c] = in[8 * i + 2 * c]; // RGB with alpha␊ |
| 1005 | ␉else if (bitDepth < 8 && colorType == 0) // greyscale␊ |
| 1006 | ␉␉for (i = 0; i < numpixels; i++) {␊ |
| 1007 | ␉␉␉uint32_t value = (PNG_readBitsFromReversedStream(&bp, in, bitDepth) * 255) /␊ |
| 1008 | ␉␉␉␉␉((1 << bitDepth) - 1); // scale value from 0 to 255␊ |
| 1009 | ␉␉␉out_data[4 * i + 0] = out_data[4 * i + 1] = out_data[4 * i + 2] = (uint8_t) value;␊ |
| 1010 | ␉␉␉out_data[4 * i + 3] = (info->key_defined && value &&␊ |
| 1011 | ␉␉␉␉␉(((1U << bitDepth) - 1U) == info->key_r) && ((1U << bitDepth) - 1U)) ? 0 : 255;␊ |
| 1012 | ␉␉}␊ |
| 1013 | ␉else if (bitDepth < 8 && colorType == 3) // palette␊ |
| 1014 | ␉␉for (i = 0; i < numpixels; i++)␊ |
| 1015 | ␉␉{␊ |
| 1016 | ␉␉␉uint32_t value = PNG_readBitsFromReversedStream(&bp, in, bitDepth);␊ |
| 1017 | ␉␉␉if (4 * value >= info->palette->size)␊ |
| 1018 | ␉␉␉␉return 47;␊ |
| 1019 | ␉␉␉for (c = 0; c < 4; c++) // get rgb colors from the palette␊ |
| 1020 | ␉␉␉␉out_data[4 * i + c] = info->palette->data[4 * value + c];␊ |
| 1021 | ␉␉}␊ |
| 1022 | ␉return 0;␊ |
| 1023 | }␊ |
| 1024 | ␊ |
| 1025 | PNG_info_t *PNG_info_new()␊ |
| 1026 | {␊ |
| 1027 | ␉PNG_info_t *info = png_alloc_malloc(sizeof (PNG_info_t));␊ |
| 1028 | ␉if (!info)␊ |
| 1029 | ␉{␊ |
| 1030 | ␉␉return NULL;␊ |
| 1031 | ␉}␊ |
| 1032 | ␉uint32_t i;␊ |
| 1033 | ␉for (i = 0; i < sizeof (PNG_info_t); i++)␊ |
| 1034 | ␉␉((uint8_t *) info)[i] = 0;␊ |
| 1035 | ␉info->palette = vector8_new(0, 0);␊ |
| 1036 | ␉info->image = vector8_new(0, 0);␊ |
| 1037 | ␉return info;␊ |
| 1038 | }␊ |
| 1039 | ␊ |
| 1040 | PNG_info_t *PNG_decode(const uint8_t *in, uint32_t size)␊ |
| 1041 | {␊ |
| 1042 | ␉PNG_info_t *info;␊ |
| 1043 | ␉PNG_error = 0;␊ |
| 1044 | ␉if (size == 0 || in == 0) {␊ |
| 1045 | ␉␉PNG_error = 48; // the given data is empty␊ |
| 1046 | ␉␉return NULL;␊ |
| 1047 | ␉}␊ |
| 1048 | ␉info = PNG_info_new();␊ |
| 1049 | ␉PNG_readPngHeader(info, in, size);␊ |
| 1050 | ␉if (PNG_error)␊ |
| 1051 | ␉␉return NULL;␊ |
| 1052 | ␉size_t pos = 33; // first byte of the first chunk after the header␊ |
| 1053 | ␉vector8_t *idat = NULL; // the data from idat chunks␊ |
| 1054 | ␉bool IEND = false, known_type = true;␊ |
| 1055 | ␉info->key_defined = false;␊ |
| 1056 | ␉// loop through the chunks, ignoring unknown chunks and stopping at IEND chunk. IDAT data is␊ |
| 1057 | ␉// put at the start of the in buffer␊ |
| 1058 | ␉while (!IEND) {␊ |
| 1059 | ␉␉size_t i, j;␊ |
| 1060 | ␉␉if (pos + 8 >= size) {␊ |
| 1061 | ␉␉␉PNG_error = 30; // error: size of the in buffer too small to contain next chunk␊ |
| 1062 | ␉␉␉return NULL;␊ |
| 1063 | ␉␉}␊ |
| 1064 | ␉␉size_t chunkLength = PNG_read32bitInt(&in[pos]);␊ |
| 1065 | ␉␉pos += 4;␊ |
| 1066 | ␉␉if (chunkLength > 0x7fffffff) {␊ |
| 1067 | ␉␉␉PNG_error = 63;␊ |
| 1068 | ␉␉␉return NULL;␊ |
| 1069 | ␉␉}␊ |
| 1070 | ␉␉if (pos + chunkLength >= size) {␊ |
| 1071 | ␉␉␉PNG_error = 35; // error: size of the in buffer too small to contain next chunk␊ |
| 1072 | ␉␉␉return NULL;␊ |
| 1073 | ␉␉}␊ |
| 1074 | ␉␉uint32_t chunkType = *(uint32_t *) &in[pos];␊ |
| 1075 | ␉␉if (chunkType == CHUNK_IDAT) { // IDAT: compressed image data chunk␊ |
| 1076 | ␉␉␉size_t offset = 0;␊ |
| 1077 | ␉␉␉if (idat) {␊ |
| 1078 | ␉␉␉␉offset = idat->size;␊ |
| 1079 | ␉␉␉␉vector8_resize(idat, offset + chunkLength);␊ |
| 1080 | ␉␉␉} else␊ |
| 1081 | ␉␉␉␉idat = vector8_new(chunkLength, 0);␊ |
| 1082 | ␊ |
| 1083 | ␉␉␉if (!idat)␊ |
| 1084 | ␉␉␉{␊ |
| 1085 | ␉␉␉␉PNG_error = 1;␊ |
| 1086 | ␉␉␉␉return NULL;␊ |
| 1087 | ␉␉␉}␊ |
| 1088 | ␉␉␉for (i = 0; i < chunkLength; i++)␊ |
| 1089 | ␉␉␉␉idat->data[offset + i] = in[pos + 4 + i];␊ |
| 1090 | ␉␉␉pos += (4 + chunkLength);␊ |
| 1091 | ␉␉} else if (chunkType == CHUNK_IEND) { // IEND␊ |
| 1092 | ␉␉␉pos += 4;␊ |
| 1093 | ␉␉␉IEND = true;␊ |
| 1094 | ␉␉} else if (chunkType == CHUNK_PLTE) { // PLTE: palette chunk␊ |
| 1095 | ␉␉␉pos += 4; // go after the 4 letters␊ |
| 1096 | ␉␉␉vector8_resize(info->palette, 4 * (chunkLength / 3));␊ |
| 1097 | ␉␉␉if (info->palette->size > (4 * 256)) {␊ |
| 1098 | ␉␉␉␉PNG_error = 38; // error: palette too big␊ |
| 1099 | ␉␉␉␉return NULL;␊ |
| 1100 | ␉␉␉}␊ |
| 1101 | ␉␉␉for (i = 0; i < info->palette->size; i += 4) {␊ |
| 1102 | ␉␉␉␉for (j = 0; j < 3; j++)␊ |
| 1103 | ␉␉␉␉␉info->palette->data[i + j] = in[pos++]; // RGB␊ |
| 1104 | ␉␉␉␉info->palette->data[i + 3] = 255; // alpha␊ |
| 1105 | ␉␉␉}␊ |
| 1106 | ␉␉} else if (chunkType == CHUNK_tRNS) { // tRNS: palette transparency chunk␊ |
| 1107 | ␉␉␉pos += 4; // go after the 4 letters␊ |
| 1108 | ␉␉␉if (info->colorType == 3) {␊ |
| 1109 | ␉␉␉␉if (4 * chunkLength > info->palette->size) {␊ |
| 1110 | ␉␉␉␉␉PNG_error = 39; // error: more alpha values given than there are palette entries␊ |
| 1111 | ␉␉␉␉␉return NULL;␊ |
| 1112 | ␉␉␉␉}␊ |
| 1113 | ␉␉␉␉for (i = 0; i < chunkLength; i++)␊ |
| 1114 | ␉␉␉␉␉info->palette->data[4 * i + 3] = in[pos++];␊ |
| 1115 | ␉␉␉} else if (info->colorType == 0) {␊ |
| 1116 | ␉␉␉␉if (chunkLength != 2) {␊ |
| 1117 | ␉␉␉␉␉PNG_error = 40; // error: this chunk must be 2 bytes for greyscale image␊ |
| 1118 | ␉␉␉␉␉return NULL;␊ |
| 1119 | ␉␉␉␉}␊ |
| 1120 | ␉␉␉␉info->key_defined = true;␊ |
| 1121 | ␉␉␉␉info->key_r = info->key_g = info->key_b = 256 * in[pos] + in[pos + 1];␊ |
| 1122 | ␉␉␉␉pos += 2;␊ |
| 1123 | ␉␉␉} else if (info->colorType == 2) {␊ |
| 1124 | ␉␉␉␉if (chunkLength != 6) {␊ |
| 1125 | ␉␉␉␉␉PNG_error = 41; // error: this chunk must be 6 bytes for RGB image␊ |
| 1126 | ␉␉␉␉␉return NULL;␊ |
| 1127 | ␉␉␉␉}␊ |
| 1128 | ␉␉␉␉info->key_defined = true;␊ |
| 1129 | ␉␉␉␉info->key_r = 256 * in[pos] + in[pos + 1];␊ |
| 1130 | ␉␉␉␉pos += 2;␊ |
| 1131 | ␉␉␉␉info->key_g = 256 * in[pos] + in[pos + 1];␊ |
| 1132 | ␉␉␉␉pos += 2;␊ |
| 1133 | ␉␉␉␉info->key_b = 256 * in[pos] + in[pos + 1];␊ |
| 1134 | ␉␉␉␉pos += 2;␊ |
| 1135 | ␉␉␉} else {␊ |
| 1136 | ␉␉␉␉PNG_error = 42; // error: tRNS chunk not allowed for other color models␊ |
| 1137 | ␉␉␉␉return NULL;␊ |
| 1138 | ␉␉␉}␊ |
| 1139 | ␉␉} else { // it's not an implemented chunk type, so ignore it: skip over the data␊ |
| 1140 | ␉␉␉if (!(in[pos + 0] & 32)) {␊ |
| 1141 | ␉␉␉␉// error: unknown critical chunk (5th bit of first byte of chunk type is 0)␊ |
| 1142 | ␉␉␉␉PNG_error = 69;␊ |
| 1143 | ␉␉␉␉return NULL;␊ |
| 1144 | ␉␉␉}␊ |
| 1145 | ␉␉␉pos += (chunkLength + 4); // skip 4 letters and uninterpreted data of unimplemented chunk␊ |
| 1146 | ␉␉␉known_type = false;␊ |
| 1147 | ␉␉}␊ |
| 1148 | ␉␉pos += 4; // step over CRC (which is ignored)␊ |
| 1149 | ␉}␊ |
| 1150 | ␉uint32_t bpp = PNG_getBpp(info);␊ |
| 1151 | ␉vector8_t *scanlines; // now the out buffer will be filled␊ |
| 1152 | ␉scanlines = vector8_new(((info->width * (info->height * bpp + 7)) / 8) + info->height, 0);␊ |
| 1153 | ␉if (!scanlines)␊ |
| 1154 | ␉{␊ |
| 1155 | ␉␉PNG_error = 1;␊ |
| 1156 | ␉␉return NULL;␊ |
| 1157 | ␉}␊ |
| 1158 | ␉PNG_error = Zlib_decompress(scanlines, idat);␊ |
| 1159 | ␉if (PNG_error)␊ |
| 1160 | ␉␉return NULL; // stop if the zlib decompressor returned an error␊ |
| 1161 | ␉size_t bytewidth = (bpp + 7) / 8, outlength = (info->height * info->width * bpp + 7) / 8;␊ |
| 1162 | ␉vector8_resize(info->image, outlength); // time to fill the out buffer␊ |
| 1163 | ␉uint8_t *out_data = outlength ? info->image->data : 0;␊ |
| 1164 | ␉if (info->interlaceMethod == 0) { // no interlace, just filter␊ |
| 1165 | ␉␉size_t y, obp, bp;␊ |
| 1166 | ␉␉size_t linestart, linelength;␊ |
| 1167 | ␉␉linestart = 0;␊ |
| 1168 | ␉␉// length in bytes of a scanline, excluding the filtertype byte␊ |
| 1169 | ␉␉linelength = (info->width * bpp + 7) / 8;␊ |
| 1170 | ␉␉if (bpp >= 8) // byte per byte␊ |
| 1171 | ␉␉␉for (y = 0; y < info->height; y++) {␊ |
| 1172 | ␉␉␉␉uint32_t filterType = scanlines->data[linestart];␊ |
| 1173 | ␉␉␉␉const uint8_t *prevline;␊ |
| 1174 | ␉␉␉␉prevline = (y == 0) ? 0 : &out_data[(y - 1) * info->width * bytewidth];␊ |
| 1175 | ␉␉␉␉PNG_unFilterScanline(&out_data[linestart - y], &scanlines->data[linestart + 1],␊ |
| 1176 | ␉␉␉␉␉␉prevline, bytewidth, filterType, linelength);␊ |
| 1177 | ␉␉␉␉if (PNG_error)␊ |
| 1178 | ␉␉␉␉␉return NULL;␊ |
| 1179 | ␉␉␉␉linestart += (1 + linelength); // go to start of next scanline␊ |
| 1180 | ␉␉} else { // less than 8 bits per pixel, so fill it up bit per bit␊ |
| 1181 | ␉␉␉vector8_t *templine; // only used if bpp < 8␊ |
| 1182 | ␉␉␉templine = vector8_new((info->width * bpp + 7) >> 3, 0);␊ |
| 1183 | ␉␉␉for (y = 0, obp = 0; y < info->height; y++) {␊ |
| 1184 | ␉␉␉␉uint32_t filterType = scanlines->data[linestart];␊ |
| 1185 | ␉␉␉␉const uint8_t *prevline;␊ |
| 1186 | ␉␉␉␉prevline = (y == 0) ? 0 : &out_data[(y - 1) * info->width * bytewidth];␊ |
| 1187 | ␉␉␉␉PNG_unFilterScanline(templine->data, &scanlines->data[linestart + 1], prevline,␊ |
| 1188 | ␉␉␉␉␉␉bytewidth, filterType, linelength);␊ |
| 1189 | ␉␉␉␉if (PNG_error)␊ |
| 1190 | ␉␉␉␉␉return NULL;␊ |
| 1191 | ␉␉␉␉for (bp = 0; bp < info->width * bpp;)␊ |
| 1192 | ␉␉␉␉␉PNG_setBitOfReversedStream(&obp, out_data, PNG_readBitFromReversedStream(&bp,␊ |
| 1193 | ␉␉␉␉␉␉␉templine->data));␊ |
| 1194 | ␉␉␉␉linestart += (1 + linelength); // go to start of next scanline␊ |
| 1195 | ␉␉␉}␊ |
| 1196 | ␉␉}␊ |
| 1197 | ␉} else { // interlaceMethod is 1 (Adam7)␊ |
| 1198 | ␉␉int i;␊ |
| 1199 | ␉␉size_t passw[7] = {␊ |
| 1200 | ␉␉␉(info->width + 7) / 8, (info->width + 3) / 8, (info->width + 3) / 4,␊ |
| 1201 | ␉␉␉(info->width + 1) / 4, (info->width + 1) / 2, (info->width + 0) / 2,␊ |
| 1202 | ␉␉␉(info->width + 0) / 1␊ |
| 1203 | ␉␉};␊ |
| 1204 | ␉␉size_t passh[7] = {␊ |
| 1205 | ␉␉␉(info->height + 7) / 8, (info->height + 7) / 8, (info->height + 3) / 8,␊ |
| 1206 | ␉␉␉(info->height + 3) / 4, (info->height + 1) / 4, (info->height + 1) / 2,␊ |
| 1207 | ␉␉␉(info->height + 0) / 2␊ |
| 1208 | ␉␉};␊ |
| 1209 | ␉␉size_t passstart[7] = { 0 };␊ |
| 1210 | ␉␉size_t pattern[28] = { 0, 4, 0, 2, 0, 1, 0, 0, 0, 4, 0, 2, 0, 1, 8, 8, 4, 4, 2, 2, 1, 8, 8,␊ |
| 1211 | ␉␉␉␉8, 4, 4, 2, 2 }; // values for the adam7 passes␊ |
| 1212 | ␉␉for (i = 0; i < 6; i++)␊ |
| 1213 | ␉␉␉passstart[i + 1] = passstart[i] + passh[i] * ((passw[i] ? 1 : 0) + (passw[i] * bpp + 7) / 8);␊ |
| 1214 | ␉␉vector8_t *scanlineo, *scanlinen; // "old" and "new" scanline␊ |
| 1215 | ␉␉scanlineo = vector8_new((info->width * bpp + 7) / 8, 0);␊ |
| 1216 | ␉␉scanlinen = vector8_new((info->width * bpp + 7) / 8, 0);␊ |
| 1217 | ␉␉for (i = 0; i < 7; i++)␊ |
| 1218 | ␉␉␉PNG_adam7Pass(out_data, scanlinen->data, scanlineo->data, &scanlines->data[passstart[i]],␊ |
| 1219 | ␉␉␉␉␉info->width, pattern[i], pattern[i + 7], pattern[i + 14], pattern[i + 21],␊ |
| 1220 | ␉␉␉␉␉passw[i], passh[i], bpp);␊ |
| 1221 | ␉}␊ |
| 1222 | ␉if (info->colorType != 6 || info->bitDepth != 8) { // conversion needed␊ |
| 1223 | ␉␉vector8_t *copy = vector8_copy(info->image); // xxx: is this copy necessary?␊ |
| 1224 | ␉␉if (!copy)␊ |
| 1225 | ␉␉{␊ |
| 1226 | ␉␉␉return NULL;␊ |
| 1227 | ␉␉}␊ |
| 1228 | ␉␉PNG_error = PNG_convert(info, info->image, copy->data);␊ |
| 1229 | ␉␉if (PNG_error)␊ |
| 1230 | ␉␉{␊ |
| 1231 | ␉␉␉return NULL;␊ |
| 1232 | ␉ }␊ |
| 1233 | ␉}␊ |
| 1234 | ␉return info;␊ |
| 1235 | }␊ |
| 1236 | ␊ |
| 1237 | /*************************************************************************************************/␊ |
| 1238 | ␊ |
| 1239 | #ifdef TEST␊ |
| 1240 | ␊ |
| 1241 | #include <stdio.h>␊ |
| 1242 | #include <sys/stat.h>␊ |
| 1243 | ␊ |
| 1244 | int main(int argc, char **argv)␊ |
| 1245 | {␊ |
| 1246 | ␉char *fname = (argc > 1) ? argv[1] : "test.png";␊ |
| 1247 | ␉PNG_info_t *info;␊ |
| 1248 | ␉struct stat statbuf;␊ |
| 1249 | ␉uint32_t insize, outsize;␊ |
| 1250 | ␉FILE *infp, *outfp;␊ |
| 1251 | ␉uint8_t *inbuf;␊ |
| 1252 | ␉uint32_t n;␊ |
| 1253 | ␊ |
| 1254 | ␉if (stat(fname, &statbuf) != 0) {␊ |
| 1255 | ␉␉perror("stat");␊ |
| 1256 | ␉␉return 1;␊ |
| 1257 | ␉} else if (!statbuf.st_size) {␊ |
| 1258 | ␉␉printf("file empty\n");␊ |
| 1259 | ␉␉return 1;␊ |
| 1260 | ␉}␊ |
| 1261 | ␉insize = (uint32_t) statbuf.st_size;␊ |
| 1262 | ␉inbuf = malloc(insize);␊ |
| 1263 | ␉infp = fopen(fname, "rb");␊ |
| 1264 | ␉if (!infp) {␊ |
| 1265 | ␉␉perror("fopen");␊ |
| 1266 | ␉␉return 1;␊ |
| 1267 | ␉} else if (fread(inbuf, 1, insize, infp) != insize) {␊ |
| 1268 | ␉␉perror("fread");␊ |
| 1269 | ␉␉return 1;␊ |
| 1270 | ␉}␊ |
| 1271 | ␉fclose(infp);␊ |
| 1272 | ␊ |
| 1273 | ␉printf("input file: %s (size: %d)\n", fname, insize);␊ |
| 1274 | ␊ |
| 1275 | ␉info = PNG_decode(inbuf, insize);␊ |
| 1276 | ␉free(inbuf);␊ |
| 1277 | ␉printf("PNG_error: %d\n", PNG_error);␊ |
| 1278 | ␉if (PNG_error != 0)␊ |
| 1279 | ␉␉return 1;␊ |
| 1280 | ␊ |
| 1281 | ␉printf("width: %d, height: %d\nfirst 16 bytes: ", info->width, info->height);␊ |
| 1282 | ␉for (n = 0; n < 16; n++)␊ |
| 1283 | ␉␉printf("%02x ", info->image->data[n]);␊ |
| 1284 | ␉printf("\n");␊ |
| 1285 | ␊ |
| 1286 | ␉outsize = info->width * info->height * 4;␊ |
| 1287 | ␉printf("image size: %d\n", outsize);␊ |
| 1288 | ␉if (outsize != info->image->size) {␊ |
| 1289 | ␉␉printf("error: image size doesn't match dimensions\n");␊ |
| 1290 | ␉␉return 1;␊ |
| 1291 | ␉}␊ |
| 1292 | ␉outfp = fopen("out.bin", "wb");␊ |
| 1293 | ␉if (!outfp) {␊ |
| 1294 | ␉␉perror("fopen");␊ |
| 1295 | ␉␉return 1;␊ |
| 1296 | ␉} else if (fwrite(info->image->data, 1, outsize, outfp) != outsize) {␊ |
| 1297 | ␉␉perror("fwrite");␊ |
| 1298 | ␉␉return 1;␊ |
| 1299 | ␉}␊ |
| 1300 | ␉fclose(outfp);␊ |
| 1301 | ␊ |
| 1302 | #ifdef ALLOC_DEBUG␊ |
| 1303 | ␉png_alloc_node_t *node;␊ |
| 1304 | ␉for (node = png_alloc_head, n = 1; node; node = node->next, n++)␊ |
| 1305 | ␉␉printf("node %d (%p) addr = %p, size = %ld\n", n, node, node->addr, node->size);␊ |
| 1306 | #endif␊ |
| 1307 | ␉png_alloc_free_all(); // also frees info and image data from PNG_decode␊ |
| 1308 | ␊ |
| 1309 | ␉return 0;␊ |
| 1310 | }␊ |
| 1311 | ␊ |
| 1312 | #endif␊ |
| 1313 | |
