Igor Sarkisov | fcf9f77 | 2020-10-06 06:14:19 -0700 | [diff] [blame] | 1 | |
| 2 | /* pngwutil.c - utilities to write a PNG file |
| 3 | * |
| 4 | * Last changed in libpng 1.4.1 [February 25, 2010] |
| 5 | * Copyright (c) 1998-2010 Glenn Randers-Pehrson |
| 6 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
| 7 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
| 8 | * |
| 9 | * This code is released under the libpng license. |
| 10 | * For conditions of distribution and use, see the disclaimer |
| 11 | * and license in png.h |
| 12 | */ |
| 13 | |
| 14 | #define PNG_NO_PEDANTIC_WARNINGS |
| 15 | #include "png.h" |
| 16 | #ifdef PNG_WRITE_SUPPORTED |
| 17 | #include "pngpriv.h" |
| 18 | |
| 19 | /* Place a 32-bit number into a buffer in PNG byte order. We work |
| 20 | * with unsigned numbers for convenience, although one supported |
| 21 | * ancillary chunk uses signed (two's complement) numbers. |
| 22 | */ |
| 23 | void PNGAPI |
| 24 | png_save_uint_32(png_bytep buf, png_uint_32 i) |
| 25 | { |
| 26 | buf[0] = (png_byte)((i >> 24) & 0xff); |
| 27 | buf[1] = (png_byte)((i >> 16) & 0xff); |
| 28 | buf[2] = (png_byte)((i >> 8) & 0xff); |
| 29 | buf[3] = (png_byte)(i & 0xff); |
| 30 | } |
| 31 | |
| 32 | #ifdef PNG_SAVE_INT_32_SUPPORTED |
| 33 | /* The png_save_int_32 function assumes integers are stored in two's |
| 34 | * complement format. If this isn't the case, then this routine needs to |
| 35 | * be modified to write data in two's complement format. |
| 36 | */ |
| 37 | void PNGAPI |
| 38 | png_save_int_32(png_bytep buf, png_int_32 i) |
| 39 | { |
| 40 | buf[0] = (png_byte)((i >> 24) & 0xff); |
| 41 | buf[1] = (png_byte)((i >> 16) & 0xff); |
| 42 | buf[2] = (png_byte)((i >> 8) & 0xff); |
| 43 | buf[3] = (png_byte)(i & 0xff); |
| 44 | } |
| 45 | #endif |
| 46 | |
| 47 | /* Place a 16-bit number into a buffer in PNG byte order. |
| 48 | * The parameter is declared unsigned int, not png_uint_16, |
| 49 | * just to avoid potential problems on pre-ANSI C compilers. |
| 50 | */ |
| 51 | void PNGAPI |
| 52 | png_save_uint_16(png_bytep buf, unsigned int i) |
| 53 | { |
| 54 | buf[0] = (png_byte)((i >> 8) & 0xff); |
| 55 | buf[1] = (png_byte)(i & 0xff); |
| 56 | } |
| 57 | |
| 58 | /* Simple function to write the signature. If we have already written |
| 59 | * the magic bytes of the signature, or more likely, the PNG stream is |
| 60 | * being embedded into another stream and doesn't need its own signature, |
| 61 | * we should call png_set_sig_bytes() to tell libpng how many of the |
| 62 | * bytes have already been written. |
| 63 | */ |
| 64 | void PNGAPI |
| 65 | png_write_sig(png_structp png_ptr) |
| 66 | { |
| 67 | png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; |
| 68 | |
| 69 | #ifdef PNG_IO_STATE_SUPPORTED |
| 70 | /* Inform the I/O callback that the signature is being written */ |
| 71 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE; |
| 72 | #endif |
| 73 | |
| 74 | /* Write the rest of the 8 byte signature */ |
| 75 | png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes], |
| 76 | (png_size_t)(8 - png_ptr->sig_bytes)); |
| 77 | if (png_ptr->sig_bytes < 3) |
| 78 | png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; |
| 79 | } |
| 80 | |
| 81 | /* Write a PNG chunk all at once. The type is an array of ASCII characters |
| 82 | * representing the chunk name. The array must be at least 4 bytes in |
| 83 | * length, and does not need to be null terminated. To be safe, pass the |
| 84 | * pre-defined chunk names here, and if you need a new one, define it |
| 85 | * where the others are defined. The length is the length of the data. |
| 86 | * All the data must be present. If that is not possible, use the |
| 87 | * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() |
| 88 | * functions instead. |
| 89 | */ |
| 90 | void PNGAPI |
| 91 | png_write_chunk(png_structp png_ptr, png_bytep chunk_name, |
| 92 | png_bytep data, png_size_t length) |
| 93 | { |
| 94 | if (png_ptr == NULL) |
| 95 | return; |
| 96 | png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length); |
| 97 | png_write_chunk_data(png_ptr, data, (png_size_t)length); |
| 98 | png_write_chunk_end(png_ptr); |
| 99 | } |
| 100 | |
| 101 | /* Write the start of a PNG chunk. The type is the chunk type. |
| 102 | * The total_length is the sum of the lengths of all the data you will be |
| 103 | * passing in png_write_chunk_data(). |
| 104 | */ |
| 105 | void PNGAPI |
| 106 | png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name, |
| 107 | png_uint_32 length) |
| 108 | { |
| 109 | png_byte buf[8]; |
| 110 | |
| 111 | png_debug2(0, "Writing %s chunk, length = %lu", chunk_name, |
| 112 | (unsigned long)length); |
| 113 | |
| 114 | if (png_ptr == NULL) |
| 115 | return; |
| 116 | |
| 117 | #ifdef PNG_IO_STATE_SUPPORTED |
| 118 | /* Inform the I/O callback that the chunk header is being written. |
| 119 | * PNG_IO_CHUNK_HDR requires a single I/O call. |
| 120 | */ |
| 121 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR; |
| 122 | #endif |
| 123 | |
| 124 | /* Write the length and the chunk name */ |
| 125 | png_save_uint_32(buf, length); |
| 126 | png_memcpy(buf + 4, chunk_name, 4); |
| 127 | png_write_data(png_ptr, buf, (png_size_t)8); |
| 128 | /* Put the chunk name into png_ptr->chunk_name */ |
| 129 | png_memcpy(png_ptr->chunk_name, chunk_name, 4); |
| 130 | /* Reset the crc and run it over the chunk name */ |
| 131 | png_reset_crc(png_ptr); |
| 132 | png_calculate_crc(png_ptr, chunk_name, 4); |
| 133 | |
| 134 | #ifdef PNG_IO_STATE_SUPPORTED |
| 135 | /* Inform the I/O callback that chunk data will (possibly) be written. |
| 136 | * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls. |
| 137 | */ |
| 138 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA; |
| 139 | #endif |
| 140 | } |
| 141 | |
| 142 | /* Write the data of a PNG chunk started with png_write_chunk_start(). |
| 143 | * Note that multiple calls to this function are allowed, and that the |
| 144 | * sum of the lengths from these calls *must* add up to the total_length |
| 145 | * given to png_write_chunk_start(). |
| 146 | */ |
| 147 | void PNGAPI |
| 148 | png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length) |
| 149 | { |
| 150 | /* Write the data, and run the CRC over it */ |
| 151 | if (png_ptr == NULL) |
| 152 | return; |
| 153 | if (data != NULL && length > 0) |
| 154 | { |
| 155 | png_write_data(png_ptr, data, length); |
| 156 | /* Update the CRC after writing the data, |
| 157 | * in case that the user I/O routine alters it. |
| 158 | */ |
| 159 | png_calculate_crc(png_ptr, data, length); |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | /* Finish a chunk started with png_write_chunk_start(). */ |
| 164 | void PNGAPI |
| 165 | png_write_chunk_end(png_structp png_ptr) |
| 166 | { |
| 167 | png_byte buf[4]; |
| 168 | |
| 169 | if (png_ptr == NULL) return; |
| 170 | |
| 171 | #ifdef PNG_IO_STATE_SUPPORTED |
| 172 | /* Inform the I/O callback that the chunk CRC is being written. |
| 173 | * PNG_IO_CHUNK_CRC requires a single I/O function call. |
| 174 | */ |
| 175 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC; |
| 176 | #endif |
| 177 | |
| 178 | /* Write the crc in a single operation */ |
| 179 | png_save_uint_32(buf, png_ptr->crc); |
| 180 | |
| 181 | png_write_data(png_ptr, buf, (png_size_t)4); |
| 182 | } |
| 183 | |
| 184 | #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED) |
| 185 | /* This pair of functions encapsulates the operation of (a) compressing a |
| 186 | * text string, and (b) issuing it later as a series of chunk data writes. |
| 187 | * The compression_state structure is shared context for these functions |
| 188 | * set up by the caller in order to make the whole mess thread-safe. |
| 189 | */ |
| 190 | |
| 191 | typedef struct |
| 192 | { |
| 193 | char *input; /* The uncompressed input data */ |
| 194 | int input_len; /* Its length */ |
| 195 | int num_output_ptr; /* Number of output pointers used */ |
| 196 | int max_output_ptr; /* Size of output_ptr */ |
| 197 | png_charpp output_ptr; /* Array of pointers to output */ |
| 198 | } compression_state; |
| 199 | |
| 200 | /* Compress given text into storage in the png_ptr structure */ |
| 201 | static int /* PRIVATE */ |
| 202 | png_text_compress(png_structp png_ptr, |
| 203 | png_charp text, png_size_t text_len, int compression, |
| 204 | compression_state *comp) |
| 205 | { |
| 206 | int ret; |
| 207 | |
| 208 | comp->num_output_ptr = 0; |
| 209 | comp->max_output_ptr = 0; |
| 210 | comp->output_ptr = NULL; |
| 211 | comp->input = NULL; |
| 212 | comp->input_len = 0; |
| 213 | |
| 214 | /* We may just want to pass the text right through */ |
| 215 | if (compression == PNG_TEXT_COMPRESSION_NONE) |
| 216 | { |
| 217 | comp->input = text; |
| 218 | comp->input_len = text_len; |
| 219 | return((int)text_len); |
| 220 | } |
| 221 | |
| 222 | if (compression >= PNG_TEXT_COMPRESSION_LAST) |
| 223 | { |
| 224 | #ifdef PNG_STDIO_SUPPORTED |
| 225 | char msg[50]; |
| 226 | png_snprintf(msg, 50, "Unknown compression type %d", compression); |
| 227 | png_warning(png_ptr, msg); |
| 228 | #else |
| 229 | png_warning(png_ptr, "Unknown compression type"); |
| 230 | #endif |
| 231 | } |
| 232 | |
| 233 | /* We can't write the chunk until we find out how much data we have, |
| 234 | * which means we need to run the compressor first and save the |
| 235 | * output. This shouldn't be a problem, as the vast majority of |
| 236 | * comments should be reasonable, but we will set up an array of |
| 237 | * malloc'd pointers to be sure. |
| 238 | * |
| 239 | * If we knew the application was well behaved, we could simplify this |
| 240 | * greatly by assuming we can always malloc an output buffer large |
| 241 | * enough to hold the compressed text ((1001 * text_len / 1000) + 12) |
| 242 | * and malloc this directly. The only time this would be a bad idea is |
| 243 | * if we can't malloc more than 64K and we have 64K of random input |
| 244 | * data, or if the input string is incredibly large (although this |
| 245 | * wouldn't cause a failure, just a slowdown due to swapping). |
| 246 | */ |
| 247 | |
| 248 | /* Set up the compression buffers */ |
| 249 | png_ptr->zstream.avail_in = (uInt)text_len; |
| 250 | png_ptr->zstream.next_in = (Bytef *)text; |
| 251 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| 252 | png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf; |
| 253 | |
| 254 | /* This is the same compression loop as in png_write_row() */ |
| 255 | do |
| 256 | { |
| 257 | /* Compress the data */ |
| 258 | ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); |
| 259 | if (ret != Z_OK) |
| 260 | { |
| 261 | /* Error */ |
| 262 | if (png_ptr->zstream.msg != NULL) |
| 263 | png_error(png_ptr, png_ptr->zstream.msg); |
| 264 | else |
| 265 | png_error(png_ptr, "zlib error"); |
| 266 | } |
| 267 | /* Check to see if we need more room */ |
| 268 | if (!(png_ptr->zstream.avail_out)) |
| 269 | { |
| 270 | /* Make sure the output array has room */ |
| 271 | if (comp->num_output_ptr >= comp->max_output_ptr) |
| 272 | { |
| 273 | int old_max; |
| 274 | |
| 275 | old_max = comp->max_output_ptr; |
| 276 | comp->max_output_ptr = comp->num_output_ptr + 4; |
| 277 | if (comp->output_ptr != NULL) |
| 278 | { |
| 279 | png_charpp old_ptr; |
| 280 | |
| 281 | old_ptr = comp->output_ptr; |
| 282 | comp->output_ptr = (png_charpp)png_malloc(png_ptr, |
| 283 | (png_alloc_size_t) |
| 284 | (comp->max_output_ptr * png_sizeof(png_charpp))); |
| 285 | png_memcpy(comp->output_ptr, old_ptr, old_max |
| 286 | * png_sizeof(png_charp)); |
| 287 | png_free(png_ptr, old_ptr); |
| 288 | } |
| 289 | else |
| 290 | comp->output_ptr = (png_charpp)png_malloc(png_ptr, |
| 291 | (png_alloc_size_t) |
| 292 | (comp->max_output_ptr * png_sizeof(png_charp))); |
| 293 | } |
| 294 | |
| 295 | /* Save the data */ |
| 296 | comp->output_ptr[comp->num_output_ptr] = |
| 297 | (png_charp)png_malloc(png_ptr, |
| 298 | (png_alloc_size_t)png_ptr->zbuf_size); |
| 299 | png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, |
| 300 | png_ptr->zbuf_size); |
| 301 | comp->num_output_ptr++; |
| 302 | |
| 303 | /* and reset the buffer */ |
| 304 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| 305 | png_ptr->zstream.next_out = png_ptr->zbuf; |
| 306 | } |
| 307 | /* Continue until we don't have any more to compress */ |
| 308 | } while (png_ptr->zstream.avail_in); |
| 309 | |
| 310 | /* Finish the compression */ |
| 311 | do |
| 312 | { |
| 313 | /* Tell zlib we are finished */ |
| 314 | ret = deflate(&png_ptr->zstream, Z_FINISH); |
| 315 | |
| 316 | if (ret == Z_OK) |
| 317 | { |
| 318 | /* Check to see if we need more room */ |
| 319 | if (!(png_ptr->zstream.avail_out)) |
| 320 | { |
| 321 | /* Check to make sure our output array has room */ |
| 322 | if (comp->num_output_ptr >= comp->max_output_ptr) |
| 323 | { |
| 324 | int old_max; |
| 325 | |
| 326 | old_max = comp->max_output_ptr; |
| 327 | comp->max_output_ptr = comp->num_output_ptr + 4; |
| 328 | if (comp->output_ptr != NULL) |
| 329 | { |
| 330 | png_charpp old_ptr; |
| 331 | |
| 332 | old_ptr = comp->output_ptr; |
| 333 | /* This could be optimized to realloc() */ |
| 334 | comp->output_ptr = (png_charpp)png_malloc(png_ptr, |
| 335 | (png_alloc_size_t)(comp->max_output_ptr * |
| 336 | png_sizeof(png_charp))); |
| 337 | png_memcpy(comp->output_ptr, old_ptr, |
| 338 | old_max * png_sizeof(png_charp)); |
| 339 | png_free(png_ptr, old_ptr); |
| 340 | } |
| 341 | else |
| 342 | comp->output_ptr = (png_charpp)png_malloc(png_ptr, |
| 343 | (png_alloc_size_t)(comp->max_output_ptr * |
| 344 | png_sizeof(png_charp))); |
| 345 | } |
| 346 | |
| 347 | /* Save the data */ |
| 348 | comp->output_ptr[comp->num_output_ptr] = |
| 349 | (png_charp)png_malloc(png_ptr, |
| 350 | (png_alloc_size_t)png_ptr->zbuf_size); |
| 351 | png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, |
| 352 | png_ptr->zbuf_size); |
| 353 | comp->num_output_ptr++; |
| 354 | |
| 355 | /* and reset the buffer pointers */ |
| 356 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| 357 | png_ptr->zstream.next_out = png_ptr->zbuf; |
| 358 | } |
| 359 | } |
| 360 | else if (ret != Z_STREAM_END) |
| 361 | { |
| 362 | /* We got an error */ |
| 363 | if (png_ptr->zstream.msg != NULL) |
| 364 | png_error(png_ptr, png_ptr->zstream.msg); |
| 365 | else |
| 366 | png_error(png_ptr, "zlib error"); |
| 367 | } |
| 368 | } while (ret != Z_STREAM_END); |
| 369 | |
| 370 | /* Text length is number of buffers plus last buffer */ |
| 371 | text_len = png_ptr->zbuf_size * comp->num_output_ptr; |
| 372 | if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) |
| 373 | text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out; |
| 374 | |
| 375 | return((int)text_len); |
| 376 | } |
| 377 | |
| 378 | /* Ship the compressed text out via chunk writes */ |
| 379 | static void /* PRIVATE */ |
| 380 | png_write_compressed_data_out(png_structp png_ptr, compression_state *comp) |
| 381 | { |
| 382 | int i; |
| 383 | |
| 384 | /* Handle the no-compression case */ |
| 385 | if (comp->input) |
| 386 | { |
| 387 | png_write_chunk_data(png_ptr, (png_bytep)comp->input, |
| 388 | (png_size_t)comp->input_len); |
| 389 | return; |
| 390 | } |
| 391 | |
| 392 | /* Write saved output buffers, if any */ |
| 393 | for (i = 0; i < comp->num_output_ptr; i++) |
| 394 | { |
| 395 | png_write_chunk_data(png_ptr, (png_bytep)comp->output_ptr[i], |
| 396 | (png_size_t)png_ptr->zbuf_size); |
| 397 | png_free(png_ptr, comp->output_ptr[i]); |
| 398 | } |
| 399 | if (comp->max_output_ptr != 0) |
| 400 | png_free(png_ptr, comp->output_ptr); |
| 401 | /* Write anything left in zbuf */ |
| 402 | if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size) |
| 403 | png_write_chunk_data(png_ptr, png_ptr->zbuf, |
| 404 | (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out)); |
| 405 | |
| 406 | /* Reset zlib for another zTXt/iTXt or image data */ |
| 407 | deflateReset(&png_ptr->zstream); |
| 408 | png_ptr->zstream.data_type = Z_BINARY; |
| 409 | } |
| 410 | #endif |
| 411 | |
| 412 | /* Write the IHDR chunk, and update the png_struct with the necessary |
| 413 | * information. Note that the rest of this code depends upon this |
| 414 | * information being correct. |
| 415 | */ |
| 416 | void /* PRIVATE */ |
| 417 | png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, |
| 418 | int bit_depth, int color_type, int compression_type, int filter_type, |
| 419 | int interlace_type) |
| 420 | { |
| 421 | PNG_IHDR; |
| 422 | int ret; |
| 423 | |
| 424 | png_byte buf[13]; /* Buffer to store the IHDR info */ |
| 425 | |
| 426 | png_debug(1, "in png_write_IHDR"); |
| 427 | |
| 428 | /* Check that we have valid input data from the application info */ |
| 429 | switch (color_type) |
| 430 | { |
| 431 | case PNG_COLOR_TYPE_GRAY: |
| 432 | switch (bit_depth) |
| 433 | { |
| 434 | case 1: |
| 435 | case 2: |
| 436 | case 4: |
| 437 | case 8: |
| 438 | case 16: png_ptr->channels = 1; break; |
| 439 | default: png_error(png_ptr, |
| 440 | "Invalid bit depth for grayscale image"); |
| 441 | } |
| 442 | break; |
| 443 | case PNG_COLOR_TYPE_RGB: |
| 444 | if (bit_depth != 8 && bit_depth != 16) |
| 445 | png_error(png_ptr, "Invalid bit depth for RGB image"); |
| 446 | png_ptr->channels = 3; |
| 447 | break; |
| 448 | case PNG_COLOR_TYPE_PALETTE: |
| 449 | switch (bit_depth) |
| 450 | { |
| 451 | case 1: |
| 452 | case 2: |
| 453 | case 4: |
| 454 | case 8: png_ptr->channels = 1; break; |
| 455 | default: png_error(png_ptr, "Invalid bit depth for paletted image"); |
| 456 | } |
| 457 | break; |
| 458 | case PNG_COLOR_TYPE_GRAY_ALPHA: |
| 459 | if (bit_depth != 8 && bit_depth != 16) |
| 460 | png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); |
| 461 | png_ptr->channels = 2; |
| 462 | break; |
| 463 | case PNG_COLOR_TYPE_RGB_ALPHA: |
| 464 | if (bit_depth != 8 && bit_depth != 16) |
| 465 | png_error(png_ptr, "Invalid bit depth for RGBA image"); |
| 466 | png_ptr->channels = 4; |
| 467 | break; |
| 468 | default: |
| 469 | png_error(png_ptr, "Invalid image color type specified"); |
| 470 | } |
| 471 | |
| 472 | if (compression_type != PNG_COMPRESSION_TYPE_BASE) |
| 473 | { |
| 474 | png_warning(png_ptr, "Invalid compression type specified"); |
| 475 | compression_type = PNG_COMPRESSION_TYPE_BASE; |
| 476 | } |
| 477 | |
| 478 | /* Write filter_method 64 (intrapixel differencing) only if |
| 479 | * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and |
| 480 | * 2. Libpng did not write a PNG signature (this filter_method is only |
| 481 | * used in PNG datastreams that are embedded in MNG datastreams) and |
| 482 | * 3. The application called png_permit_mng_features with a mask that |
| 483 | * included PNG_FLAG_MNG_FILTER_64 and |
| 484 | * 4. The filter_method is 64 and |
| 485 | * 5. The color_type is RGB or RGBA |
| 486 | */ |
| 487 | if ( |
| 488 | #ifdef PNG_MNG_FEATURES_SUPPORTED |
| 489 | !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && |
| 490 | ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) && |
| 491 | (color_type == PNG_COLOR_TYPE_RGB || |
| 492 | color_type == PNG_COLOR_TYPE_RGB_ALPHA) && |
| 493 | (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) && |
| 494 | #endif |
| 495 | filter_type != PNG_FILTER_TYPE_BASE) |
| 496 | { |
| 497 | png_warning(png_ptr, "Invalid filter type specified"); |
| 498 | filter_type = PNG_FILTER_TYPE_BASE; |
| 499 | } |
| 500 | |
| 501 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| 502 | if (interlace_type != PNG_INTERLACE_NONE && |
| 503 | interlace_type != PNG_INTERLACE_ADAM7) |
| 504 | { |
| 505 | png_warning(png_ptr, "Invalid interlace type specified"); |
| 506 | interlace_type = PNG_INTERLACE_ADAM7; |
| 507 | } |
| 508 | #else |
| 509 | interlace_type=PNG_INTERLACE_NONE; |
| 510 | #endif |
| 511 | |
| 512 | /* Save the relevent information */ |
| 513 | png_ptr->bit_depth = (png_byte)bit_depth; |
| 514 | png_ptr->color_type = (png_byte)color_type; |
| 515 | png_ptr->interlaced = (png_byte)interlace_type; |
| 516 | #ifdef PNG_MNG_FEATURES_SUPPORTED |
| 517 | png_ptr->filter_type = (png_byte)filter_type; |
| 518 | #endif |
| 519 | png_ptr->compression_type = (png_byte)compression_type; |
| 520 | png_ptr->width = width; |
| 521 | png_ptr->height = height; |
| 522 | |
| 523 | png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); |
| 524 | png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); |
| 525 | /* Set the usr info, so any transformations can modify it */ |
| 526 | png_ptr->usr_width = png_ptr->width; |
| 527 | png_ptr->usr_bit_depth = png_ptr->bit_depth; |
| 528 | png_ptr->usr_channels = png_ptr->channels; |
| 529 | |
| 530 | /* Pack the header information into the buffer */ |
| 531 | png_save_uint_32(buf, width); |
| 532 | png_save_uint_32(buf + 4, height); |
| 533 | buf[8] = (png_byte)bit_depth; |
| 534 | buf[9] = (png_byte)color_type; |
| 535 | buf[10] = (png_byte)compression_type; |
| 536 | buf[11] = (png_byte)filter_type; |
| 537 | buf[12] = (png_byte)interlace_type; |
| 538 | |
| 539 | /* Write the chunk */ |
| 540 | png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13); |
| 541 | |
| 542 | /* Initialize zlib with PNG info */ |
| 543 | png_ptr->zstream.zalloc = png_zalloc; |
| 544 | png_ptr->zstream.zfree = png_zfree; |
| 545 | png_ptr->zstream.opaque = (voidpf)png_ptr; |
| 546 | if (!(png_ptr->do_filter)) |
| 547 | { |
| 548 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || |
| 549 | png_ptr->bit_depth < 8) |
| 550 | png_ptr->do_filter = PNG_FILTER_NONE; |
| 551 | else |
| 552 | png_ptr->do_filter = PNG_ALL_FILTERS; |
| 553 | } |
| 554 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)) |
| 555 | { |
| 556 | if (png_ptr->do_filter != PNG_FILTER_NONE) |
| 557 | png_ptr->zlib_strategy = Z_FILTERED; |
| 558 | else |
| 559 | png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY; |
| 560 | } |
| 561 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL)) |
| 562 | png_ptr->zlib_level = Z_DEFAULT_COMPRESSION; |
| 563 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL)) |
| 564 | png_ptr->zlib_mem_level = 8; |
| 565 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS)) |
| 566 | png_ptr->zlib_window_bits = 15; |
| 567 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD)) |
| 568 | png_ptr->zlib_method = 8; |
| 569 | ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, |
| 570 | png_ptr->zlib_method, png_ptr->zlib_window_bits, |
| 571 | png_ptr->zlib_mem_level, png_ptr->zlib_strategy); |
| 572 | if (ret != Z_OK) |
| 573 | { |
| 574 | if (ret == Z_VERSION_ERROR) png_error(png_ptr, |
| 575 | "zlib failed to initialize compressor -- version error"); |
| 576 | if (ret == Z_STREAM_ERROR) png_error(png_ptr, |
| 577 | "zlib failed to initialize compressor -- stream error"); |
| 578 | if (ret == Z_MEM_ERROR) png_error(png_ptr, |
| 579 | "zlib failed to initialize compressor -- mem error"); |
| 580 | png_error(png_ptr, "zlib failed to initialize compressor"); |
| 581 | } |
| 582 | png_ptr->zstream.next_out = png_ptr->zbuf; |
| 583 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| 584 | /* libpng is not interested in zstream.data_type */ |
| 585 | /* Set it to a predefined value, to avoid its evaluation inside zlib */ |
| 586 | png_ptr->zstream.data_type = Z_BINARY; |
| 587 | |
| 588 | png_ptr->mode = PNG_HAVE_IHDR; |
| 589 | } |
| 590 | |
| 591 | /* Write the palette. We are careful not to trust png_color to be in the |
| 592 | * correct order for PNG, so people can redefine it to any convenient |
| 593 | * structure. |
| 594 | */ |
| 595 | void /* PRIVATE */ |
| 596 | png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal) |
| 597 | { |
| 598 | PNG_PLTE; |
| 599 | png_uint_32 i; |
| 600 | png_colorp pal_ptr; |
| 601 | png_byte buf[3]; |
| 602 | |
| 603 | png_debug(1, "in png_write_PLTE"); |
| 604 | |
| 605 | if (( |
| 606 | #ifdef PNG_MNG_FEATURES_SUPPORTED |
| 607 | !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) && |
| 608 | #endif |
| 609 | num_pal == 0) || num_pal > 256) |
| 610 | { |
| 611 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 612 | { |
| 613 | png_error(png_ptr, "Invalid number of colors in palette"); |
| 614 | } |
| 615 | else |
| 616 | { |
| 617 | png_warning(png_ptr, "Invalid number of colors in palette"); |
| 618 | return; |
| 619 | } |
| 620 | } |
| 621 | |
| 622 | if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) |
| 623 | { |
| 624 | png_warning(png_ptr, |
| 625 | "Ignoring request to write a PLTE chunk in grayscale PNG"); |
| 626 | return; |
| 627 | } |
| 628 | |
| 629 | png_ptr->num_palette = (png_uint_16)num_pal; |
| 630 | png_debug1(3, "num_palette = %d", png_ptr->num_palette); |
| 631 | |
| 632 | png_write_chunk_start(png_ptr, (png_bytep)png_PLTE, |
| 633 | (png_uint_32)(num_pal * 3)); |
| 634 | #ifdef PNG_POINTER_INDEXING_SUPPORTED |
| 635 | for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) |
| 636 | { |
| 637 | buf[0] = pal_ptr->red; |
| 638 | buf[1] = pal_ptr->green; |
| 639 | buf[2] = pal_ptr->blue; |
| 640 | png_write_chunk_data(png_ptr, buf, (png_size_t)3); |
| 641 | } |
| 642 | #else |
| 643 | /* This is a little slower but some buggy compilers need to do this |
| 644 | * instead |
| 645 | */ |
| 646 | pal_ptr=palette; |
| 647 | for (i = 0; i < num_pal; i++) |
| 648 | { |
| 649 | buf[0] = pal_ptr[i].red; |
| 650 | buf[1] = pal_ptr[i].green; |
| 651 | buf[2] = pal_ptr[i].blue; |
| 652 | png_write_chunk_data(png_ptr, buf, (png_size_t)3); |
| 653 | } |
| 654 | #endif |
| 655 | png_write_chunk_end(png_ptr); |
| 656 | png_ptr->mode |= PNG_HAVE_PLTE; |
| 657 | } |
| 658 | |
| 659 | /* Write an IDAT chunk */ |
| 660 | void /* PRIVATE */ |
| 661 | png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) |
| 662 | { |
| 663 | PNG_IDAT; |
| 664 | |
| 665 | png_debug(1, "in png_write_IDAT"); |
| 666 | |
| 667 | /* Optimize the CMF field in the zlib stream. */ |
| 668 | /* This hack of the zlib stream is compliant to the stream specification. */ |
| 669 | if (!(png_ptr->mode & PNG_HAVE_IDAT) && |
| 670 | png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) |
| 671 | { |
| 672 | unsigned int z_cmf = data[0]; /* zlib compression method and flags */ |
| 673 | if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) |
| 674 | { |
| 675 | /* Avoid memory underflows and multiplication overflows. |
| 676 | * |
| 677 | * The conditions below are practically always satisfied; |
| 678 | * however, they still must be checked. |
| 679 | */ |
| 680 | if (length >= 2 && |
| 681 | png_ptr->height < 16384 && png_ptr->width < 16384) |
| 682 | { |
| 683 | png_uint_32 uncompressed_idat_size = png_ptr->height * |
| 684 | ((png_ptr->width * |
| 685 | png_ptr->channels * png_ptr->bit_depth + 15) >> 3); |
| 686 | unsigned int z_cinfo = z_cmf >> 4; |
| 687 | unsigned int half_z_window_size = 1 << (z_cinfo + 7); |
| 688 | while (uncompressed_idat_size <= half_z_window_size && |
| 689 | half_z_window_size >= 256) |
| 690 | { |
| 691 | z_cinfo--; |
| 692 | half_z_window_size >>= 1; |
| 693 | } |
| 694 | z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); |
| 695 | if (data[0] != (png_byte)z_cmf) |
| 696 | { |
| 697 | data[0] = (png_byte)z_cmf; |
| 698 | data[1] &= 0xe0; |
| 699 | data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f); |
| 700 | } |
| 701 | } |
| 702 | } |
| 703 | else |
| 704 | png_error(png_ptr, |
| 705 | "Invalid zlib compression method or flags in IDAT"); |
| 706 | } |
| 707 | |
| 708 | png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length); |
| 709 | png_ptr->mode |= PNG_HAVE_IDAT; |
| 710 | } |
| 711 | |
| 712 | /* Write an IEND chunk */ |
| 713 | void /* PRIVATE */ |
| 714 | png_write_IEND(png_structp png_ptr) |
| 715 | { |
| 716 | PNG_IEND; |
| 717 | |
| 718 | png_debug(1, "in png_write_IEND"); |
| 719 | |
| 720 | png_write_chunk(png_ptr, (png_bytep)png_IEND, NULL, |
| 721 | (png_size_t)0); |
| 722 | png_ptr->mode |= PNG_HAVE_IEND; |
| 723 | } |
| 724 | |
| 725 | #ifdef PNG_WRITE_gAMA_SUPPORTED |
| 726 | /* Write a gAMA chunk */ |
| 727 | #ifdef PNG_FLOATING_POINT_SUPPORTED |
| 728 | void /* PRIVATE */ |
| 729 | png_write_gAMA(png_structp png_ptr, double file_gamma) |
| 730 | { |
| 731 | PNG_gAMA; |
| 732 | png_uint_32 igamma; |
| 733 | png_byte buf[4]; |
| 734 | |
| 735 | png_debug(1, "in png_write_gAMA"); |
| 736 | |
| 737 | /* file_gamma is saved in 1/100,000ths */ |
| 738 | igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5); |
| 739 | png_save_uint_32(buf, igamma); |
| 740 | png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4); |
| 741 | } |
| 742 | #endif |
| 743 | #ifdef PNG_FIXED_POINT_SUPPORTED |
| 744 | void /* PRIVATE */ |
| 745 | png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma) |
| 746 | { |
| 747 | PNG_gAMA; |
| 748 | png_byte buf[4]; |
| 749 | |
| 750 | png_debug(1, "in png_write_gAMA"); |
| 751 | |
| 752 | /* file_gamma is saved in 1/100,000ths */ |
| 753 | png_save_uint_32(buf, (png_uint_32)file_gamma); |
| 754 | png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4); |
| 755 | } |
| 756 | #endif |
| 757 | #endif |
| 758 | |
| 759 | #ifdef PNG_WRITE_sRGB_SUPPORTED |
| 760 | /* Write a sRGB chunk */ |
| 761 | void /* PRIVATE */ |
| 762 | png_write_sRGB(png_structp png_ptr, int srgb_intent) |
| 763 | { |
| 764 | PNG_sRGB; |
| 765 | png_byte buf[1]; |
| 766 | |
| 767 | png_debug(1, "in png_write_sRGB"); |
| 768 | |
| 769 | if (srgb_intent >= PNG_sRGB_INTENT_LAST) |
| 770 | png_warning(png_ptr, |
| 771 | "Invalid sRGB rendering intent specified"); |
| 772 | buf[0]=(png_byte)srgb_intent; |
| 773 | png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1); |
| 774 | } |
| 775 | #endif |
| 776 | |
| 777 | #ifdef PNG_WRITE_iCCP_SUPPORTED |
| 778 | /* Write an iCCP chunk */ |
| 779 | void /* PRIVATE */ |
| 780 | png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type, |
| 781 | png_charp profile, int profile_len) |
| 782 | { |
| 783 | PNG_iCCP; |
| 784 | png_size_t name_len; |
| 785 | png_charp new_name; |
| 786 | compression_state comp; |
| 787 | int embedded_profile_len = 0; |
| 788 | |
| 789 | png_debug(1, "in png_write_iCCP"); |
| 790 | |
| 791 | comp.num_output_ptr = 0; |
| 792 | comp.max_output_ptr = 0; |
| 793 | comp.output_ptr = NULL; |
| 794 | comp.input = NULL; |
| 795 | comp.input_len = 0; |
| 796 | |
| 797 | if ((name_len = png_check_keyword(png_ptr, name, |
| 798 | &new_name)) == 0) |
| 799 | return; |
| 800 | |
| 801 | if (compression_type != PNG_COMPRESSION_TYPE_BASE) |
| 802 | png_warning(png_ptr, "Unknown compression type in iCCP chunk"); |
| 803 | |
| 804 | if (profile == NULL) |
| 805 | profile_len = 0; |
| 806 | |
| 807 | if (profile_len > 3) |
| 808 | embedded_profile_len = |
| 809 | ((*( (png_bytep)profile ))<<24) | |
| 810 | ((*( (png_bytep)profile + 1))<<16) | |
| 811 | ((*( (png_bytep)profile + 2))<< 8) | |
| 812 | ((*( (png_bytep)profile + 3)) ); |
| 813 | |
| 814 | if (embedded_profile_len < 0) |
| 815 | { |
| 816 | png_warning(png_ptr, |
| 817 | "Embedded profile length in iCCP chunk is negative"); |
| 818 | png_free(png_ptr, new_name); |
| 819 | return; |
| 820 | } |
| 821 | |
| 822 | if (profile_len < embedded_profile_len) |
| 823 | { |
| 824 | png_warning(png_ptr, |
| 825 | "Embedded profile length too large in iCCP chunk"); |
| 826 | png_free(png_ptr, new_name); |
| 827 | return; |
| 828 | } |
| 829 | |
| 830 | if (profile_len > embedded_profile_len) |
| 831 | { |
| 832 | png_warning(png_ptr, |
| 833 | "Truncating profile to actual length in iCCP chunk"); |
| 834 | profile_len = embedded_profile_len; |
| 835 | } |
| 836 | |
| 837 | if (profile_len) |
| 838 | profile_len = png_text_compress(png_ptr, profile, |
| 839 | (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp); |
| 840 | |
| 841 | /* Make sure we include the NULL after the name and the compression type */ |
| 842 | png_write_chunk_start(png_ptr, (png_bytep)png_iCCP, |
| 843 | (png_uint_32)(name_len + profile_len + 2)); |
| 844 | new_name[name_len + 1] = 0x00; |
| 845 | png_write_chunk_data(png_ptr, (png_bytep)new_name, |
| 846 | (png_size_t)(name_len + 2)); |
| 847 | |
| 848 | if (profile_len) |
| 849 | png_write_compressed_data_out(png_ptr, &comp); |
| 850 | |
| 851 | png_write_chunk_end(png_ptr); |
| 852 | png_free(png_ptr, new_name); |
| 853 | } |
| 854 | #endif |
| 855 | |
| 856 | #ifdef PNG_WRITE_sPLT_SUPPORTED |
| 857 | /* Write a sPLT chunk */ |
| 858 | void /* PRIVATE */ |
| 859 | png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette) |
| 860 | { |
| 861 | PNG_sPLT; |
| 862 | png_size_t name_len; |
| 863 | png_charp new_name; |
| 864 | png_byte entrybuf[10]; |
| 865 | png_size_t entry_size = (spalette->depth == 8 ? 6 : 10); |
| 866 | png_size_t palette_size = entry_size * spalette->nentries; |
| 867 | png_sPLT_entryp ep; |
| 868 | #ifndef PNG_POINTER_INDEXING_SUPPORTED |
| 869 | int i; |
| 870 | #endif |
| 871 | |
| 872 | png_debug(1, "in png_write_sPLT"); |
| 873 | |
| 874 | if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0) |
| 875 | return; |
| 876 | |
| 877 | /* Make sure we include the NULL after the name */ |
| 878 | png_write_chunk_start(png_ptr, (png_bytep)png_sPLT, |
| 879 | (png_uint_32)(name_len + 2 + palette_size)); |
| 880 | png_write_chunk_data(png_ptr, (png_bytep)new_name, |
| 881 | (png_size_t)(name_len + 1)); |
| 882 | png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, (png_size_t)1); |
| 883 | |
| 884 | /* Loop through each palette entry, writing appropriately */ |
| 885 | #ifdef PNG_POINTER_INDEXING_SUPPORTED |
| 886 | for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++) |
| 887 | { |
| 888 | if (spalette->depth == 8) |
| 889 | { |
| 890 | entrybuf[0] = (png_byte)ep->red; |
| 891 | entrybuf[1] = (png_byte)ep->green; |
| 892 | entrybuf[2] = (png_byte)ep->blue; |
| 893 | entrybuf[3] = (png_byte)ep->alpha; |
| 894 | png_save_uint_16(entrybuf + 4, ep->frequency); |
| 895 | } |
| 896 | else |
| 897 | { |
| 898 | png_save_uint_16(entrybuf + 0, ep->red); |
| 899 | png_save_uint_16(entrybuf + 2, ep->green); |
| 900 | png_save_uint_16(entrybuf + 4, ep->blue); |
| 901 | png_save_uint_16(entrybuf + 6, ep->alpha); |
| 902 | png_save_uint_16(entrybuf + 8, ep->frequency); |
| 903 | } |
| 904 | png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); |
| 905 | } |
| 906 | #else |
| 907 | ep=spalette->entries; |
| 908 | for (i=0; i>spalette->nentries; i++) |
| 909 | { |
| 910 | if (spalette->depth == 8) |
| 911 | { |
| 912 | entrybuf[0] = (png_byte)ep[i].red; |
| 913 | entrybuf[1] = (png_byte)ep[i].green; |
| 914 | entrybuf[2] = (png_byte)ep[i].blue; |
| 915 | entrybuf[3] = (png_byte)ep[i].alpha; |
| 916 | png_save_uint_16(entrybuf + 4, ep[i].frequency); |
| 917 | } |
| 918 | else |
| 919 | { |
| 920 | png_save_uint_16(entrybuf + 0, ep[i].red); |
| 921 | png_save_uint_16(entrybuf + 2, ep[i].green); |
| 922 | png_save_uint_16(entrybuf + 4, ep[i].blue); |
| 923 | png_save_uint_16(entrybuf + 6, ep[i].alpha); |
| 924 | png_save_uint_16(entrybuf + 8, ep[i].frequency); |
| 925 | } |
| 926 | png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); |
| 927 | } |
| 928 | #endif |
| 929 | |
| 930 | png_write_chunk_end(png_ptr); |
| 931 | png_free(png_ptr, new_name); |
| 932 | } |
| 933 | #endif |
| 934 | |
| 935 | #ifdef PNG_WRITE_sBIT_SUPPORTED |
| 936 | /* Write the sBIT chunk */ |
| 937 | void /* PRIVATE */ |
| 938 | png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type) |
| 939 | { |
| 940 | PNG_sBIT; |
| 941 | png_byte buf[4]; |
| 942 | png_size_t size; |
| 943 | |
| 944 | png_debug(1, "in png_write_sBIT"); |
| 945 | |
| 946 | /* Make sure we don't depend upon the order of PNG_COLOR_8 */ |
| 947 | if (color_type & PNG_COLOR_MASK_COLOR) |
| 948 | { |
| 949 | png_byte maxbits; |
| 950 | |
| 951 | maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 : |
| 952 | png_ptr->usr_bit_depth); |
| 953 | if (sbit->red == 0 || sbit->red > maxbits || |
| 954 | sbit->green == 0 || sbit->green > maxbits || |
| 955 | sbit->blue == 0 || sbit->blue > maxbits) |
| 956 | { |
| 957 | png_warning(png_ptr, "Invalid sBIT depth specified"); |
| 958 | return; |
| 959 | } |
| 960 | buf[0] = sbit->red; |
| 961 | buf[1] = sbit->green; |
| 962 | buf[2] = sbit->blue; |
| 963 | size = 3; |
| 964 | } |
| 965 | else |
| 966 | { |
| 967 | if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) |
| 968 | { |
| 969 | png_warning(png_ptr, "Invalid sBIT depth specified"); |
| 970 | return; |
| 971 | } |
| 972 | buf[0] = sbit->gray; |
| 973 | size = 1; |
| 974 | } |
| 975 | |
| 976 | if (color_type & PNG_COLOR_MASK_ALPHA) |
| 977 | { |
| 978 | if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) |
| 979 | { |
| 980 | png_warning(png_ptr, "Invalid sBIT depth specified"); |
| 981 | return; |
| 982 | } |
| 983 | buf[size++] = sbit->alpha; |
| 984 | } |
| 985 | |
| 986 | png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size); |
| 987 | } |
| 988 | #endif |
| 989 | |
| 990 | #ifdef PNG_WRITE_cHRM_SUPPORTED |
| 991 | /* Write the cHRM chunk */ |
| 992 | #ifdef PNG_FLOATING_POINT_SUPPORTED |
| 993 | void /* PRIVATE */ |
| 994 | png_write_cHRM(png_structp png_ptr, double white_x, double white_y, |
| 995 | double red_x, double red_y, double green_x, double green_y, |
| 996 | double blue_x, double blue_y) |
| 997 | { |
| 998 | PNG_cHRM; |
| 999 | png_byte buf[32]; |
| 1000 | |
| 1001 | png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y, |
| 1002 | int_green_x, int_green_y, int_blue_x, int_blue_y; |
| 1003 | |
| 1004 | png_debug(1, "in png_write_cHRM"); |
| 1005 | |
| 1006 | int_white_x = (png_uint_32)(white_x * 100000.0 + 0.5); |
| 1007 | int_white_y = (png_uint_32)(white_y * 100000.0 + 0.5); |
| 1008 | int_red_x = (png_uint_32)(red_x * 100000.0 + 0.5); |
| 1009 | int_red_y = (png_uint_32)(red_y * 100000.0 + 0.5); |
| 1010 | int_green_x = (png_uint_32)(green_x * 100000.0 + 0.5); |
| 1011 | int_green_y = (png_uint_32)(green_y * 100000.0 + 0.5); |
| 1012 | int_blue_x = (png_uint_32)(blue_x * 100000.0 + 0.5); |
| 1013 | int_blue_y = (png_uint_32)(blue_y * 100000.0 + 0.5); |
| 1014 | |
| 1015 | #ifdef PNG_CHECK_cHRM_SUPPORTED |
| 1016 | if (png_check_cHRM_fixed(png_ptr, int_white_x, int_white_y, |
| 1017 | int_red_x, int_red_y, int_green_x, int_green_y, int_blue_x, int_blue_y)) |
| 1018 | #endif |
| 1019 | { |
| 1020 | /* Each value is saved in 1/100,000ths */ |
| 1021 | |
| 1022 | png_save_uint_32(buf, int_white_x); |
| 1023 | png_save_uint_32(buf + 4, int_white_y); |
| 1024 | |
| 1025 | png_save_uint_32(buf + 8, int_red_x); |
| 1026 | png_save_uint_32(buf + 12, int_red_y); |
| 1027 | |
| 1028 | png_save_uint_32(buf + 16, int_green_x); |
| 1029 | png_save_uint_32(buf + 20, int_green_y); |
| 1030 | |
| 1031 | png_save_uint_32(buf + 24, int_blue_x); |
| 1032 | png_save_uint_32(buf + 28, int_blue_y); |
| 1033 | |
| 1034 | png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32); |
| 1035 | } |
| 1036 | } |
| 1037 | #endif |
| 1038 | #ifdef PNG_FIXED_POINT_SUPPORTED |
| 1039 | void /* PRIVATE */ |
| 1040 | png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, |
| 1041 | png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y, |
| 1042 | png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x, |
| 1043 | png_fixed_point blue_y) |
| 1044 | { |
| 1045 | PNG_cHRM; |
| 1046 | png_byte buf[32]; |
| 1047 | |
| 1048 | png_debug(1, "in png_write_cHRM"); |
| 1049 | |
| 1050 | /* Each value is saved in 1/100,000ths */ |
| 1051 | #ifdef PNG_CHECK_cHRM_SUPPORTED |
| 1052 | if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y, |
| 1053 | green_x, green_y, blue_x, blue_y)) |
| 1054 | #endif |
| 1055 | { |
| 1056 | png_save_uint_32(buf, (png_uint_32)white_x); |
| 1057 | png_save_uint_32(buf + 4, (png_uint_32)white_y); |
| 1058 | |
| 1059 | png_save_uint_32(buf + 8, (png_uint_32)red_x); |
| 1060 | png_save_uint_32(buf + 12, (png_uint_32)red_y); |
| 1061 | |
| 1062 | png_save_uint_32(buf + 16, (png_uint_32)green_x); |
| 1063 | png_save_uint_32(buf + 20, (png_uint_32)green_y); |
| 1064 | |
| 1065 | png_save_uint_32(buf + 24, (png_uint_32)blue_x); |
| 1066 | png_save_uint_32(buf + 28, (png_uint_32)blue_y); |
| 1067 | |
| 1068 | png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32); |
| 1069 | } |
| 1070 | } |
| 1071 | #endif |
| 1072 | #endif |
| 1073 | |
| 1074 | #ifdef PNG_WRITE_tRNS_SUPPORTED |
| 1075 | /* Write the tRNS chunk */ |
| 1076 | void /* PRIVATE */ |
| 1077 | png_write_tRNS(png_structp png_ptr, png_bytep trans_alpha, png_color_16p tran, |
| 1078 | int num_trans, int color_type) |
| 1079 | { |
| 1080 | PNG_tRNS; |
| 1081 | png_byte buf[6]; |
| 1082 | |
| 1083 | png_debug(1, "in png_write_tRNS"); |
| 1084 | |
| 1085 | if (color_type == PNG_COLOR_TYPE_PALETTE) |
| 1086 | { |
| 1087 | if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) |
| 1088 | { |
| 1089 | png_warning(png_ptr, "Invalid number of transparent colors specified"); |
| 1090 | return; |
| 1091 | } |
| 1092 | /* Write the chunk out as it is */ |
| 1093 | png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans_alpha, |
| 1094 | (png_size_t)num_trans); |
| 1095 | } |
| 1096 | else if (color_type == PNG_COLOR_TYPE_GRAY) |
| 1097 | { |
| 1098 | /* One 16 bit value */ |
| 1099 | if (tran->gray >= (1 << png_ptr->bit_depth)) |
| 1100 | { |
| 1101 | png_warning(png_ptr, |
| 1102 | "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); |
| 1103 | return; |
| 1104 | } |
| 1105 | png_save_uint_16(buf, tran->gray); |
| 1106 | png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2); |
| 1107 | } |
| 1108 | else if (color_type == PNG_COLOR_TYPE_RGB) |
| 1109 | { |
| 1110 | /* Three 16 bit values */ |
| 1111 | png_save_uint_16(buf, tran->red); |
| 1112 | png_save_uint_16(buf + 2, tran->green); |
| 1113 | png_save_uint_16(buf + 4, tran->blue); |
| 1114 | if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) |
| 1115 | { |
| 1116 | png_warning(png_ptr, |
| 1117 | "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); |
| 1118 | return; |
| 1119 | } |
| 1120 | png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6); |
| 1121 | } |
| 1122 | else |
| 1123 | { |
| 1124 | png_warning(png_ptr, "Can't write tRNS with an alpha channel"); |
| 1125 | } |
| 1126 | } |
| 1127 | #endif |
| 1128 | |
| 1129 | #ifdef PNG_WRITE_bKGD_SUPPORTED |
| 1130 | /* Write the background chunk */ |
| 1131 | void /* PRIVATE */ |
| 1132 | png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type) |
| 1133 | { |
| 1134 | PNG_bKGD; |
| 1135 | png_byte buf[6]; |
| 1136 | |
| 1137 | png_debug(1, "in png_write_bKGD"); |
| 1138 | |
| 1139 | if (color_type == PNG_COLOR_TYPE_PALETTE) |
| 1140 | { |
| 1141 | if ( |
| 1142 | #ifdef PNG_MNG_FEATURES_SUPPORTED |
| 1143 | (png_ptr->num_palette || |
| 1144 | (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) && |
| 1145 | #endif |
| 1146 | back->index >= png_ptr->num_palette) |
| 1147 | { |
| 1148 | png_warning(png_ptr, "Invalid background palette index"); |
| 1149 | return; |
| 1150 | } |
| 1151 | buf[0] = back->index; |
| 1152 | png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1); |
| 1153 | } |
| 1154 | else if (color_type & PNG_COLOR_MASK_COLOR) |
| 1155 | { |
| 1156 | png_save_uint_16(buf, back->red); |
| 1157 | png_save_uint_16(buf + 2, back->green); |
| 1158 | png_save_uint_16(buf + 4, back->blue); |
| 1159 | if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) |
| 1160 | { |
| 1161 | png_warning(png_ptr, |
| 1162 | "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); |
| 1163 | return; |
| 1164 | } |
| 1165 | png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6); |
| 1166 | } |
| 1167 | else |
| 1168 | { |
| 1169 | if (back->gray >= (1 << png_ptr->bit_depth)) |
| 1170 | { |
| 1171 | png_warning(png_ptr, |
| 1172 | "Ignoring attempt to write bKGD chunk out-of-range for bit_depth"); |
| 1173 | return; |
| 1174 | } |
| 1175 | png_save_uint_16(buf, back->gray); |
| 1176 | png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2); |
| 1177 | } |
| 1178 | } |
| 1179 | #endif |
| 1180 | |
| 1181 | #ifdef PNG_WRITE_hIST_SUPPORTED |
| 1182 | /* Write the histogram */ |
| 1183 | void /* PRIVATE */ |
| 1184 | png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist) |
| 1185 | { |
| 1186 | PNG_hIST; |
| 1187 | int i; |
| 1188 | png_byte buf[3]; |
| 1189 | |
| 1190 | png_debug(1, "in png_write_hIST"); |
| 1191 | |
| 1192 | if (num_hist > (int)png_ptr->num_palette) |
| 1193 | { |
| 1194 | png_debug2(3, "num_hist = %d, num_palette = %d", num_hist, |
| 1195 | png_ptr->num_palette); |
| 1196 | png_warning(png_ptr, "Invalid number of histogram entries specified"); |
| 1197 | return; |
| 1198 | } |
| 1199 | |
| 1200 | png_write_chunk_start(png_ptr, (png_bytep)png_hIST, |
| 1201 | (png_uint_32)(num_hist * 2)); |
| 1202 | for (i = 0; i < num_hist; i++) |
| 1203 | { |
| 1204 | png_save_uint_16(buf, hist[i]); |
| 1205 | png_write_chunk_data(png_ptr, buf, (png_size_t)2); |
| 1206 | } |
| 1207 | png_write_chunk_end(png_ptr); |
| 1208 | } |
| 1209 | #endif |
| 1210 | |
| 1211 | #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \ |
| 1212 | defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) |
| 1213 | /* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, |
| 1214 | * and if invalid, correct the keyword rather than discarding the entire |
| 1215 | * chunk. The PNG 1.0 specification requires keywords 1-79 characters in |
| 1216 | * length, forbids leading or trailing whitespace, multiple internal spaces, |
| 1217 | * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. |
| 1218 | * |
| 1219 | * The new_key is allocated to hold the corrected keyword and must be freed |
| 1220 | * by the calling routine. This avoids problems with trying to write to |
| 1221 | * static keywords without having to have duplicate copies of the strings. |
| 1222 | */ |
| 1223 | png_size_t /* PRIVATE */ |
| 1224 | png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key) |
| 1225 | { |
| 1226 | png_size_t key_len; |
| 1227 | png_charp kp, dp; |
| 1228 | int kflag; |
| 1229 | int kwarn=0; |
| 1230 | |
| 1231 | png_debug(1, "in png_check_keyword"); |
| 1232 | |
| 1233 | *new_key = NULL; |
| 1234 | |
| 1235 | if (key == NULL || (key_len = png_strlen(key)) == 0) |
| 1236 | { |
| 1237 | png_warning(png_ptr, "zero length keyword"); |
| 1238 | return ((png_size_t)0); |
| 1239 | } |
| 1240 | |
| 1241 | png_debug1(2, "Keyword to be checked is '%s'", key); |
| 1242 | |
| 1243 | *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2)); |
| 1244 | if (*new_key == NULL) |
| 1245 | { |
| 1246 | png_warning(png_ptr, "Out of memory while procesing keyword"); |
| 1247 | return ((png_size_t)0); |
| 1248 | } |
| 1249 | |
| 1250 | /* Replace non-printing characters with a blank and print a warning */ |
| 1251 | for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++) |
| 1252 | { |
| 1253 | if ((png_byte)*kp < 0x20 || |
| 1254 | ((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1)) |
| 1255 | { |
| 1256 | #ifdef PNG_STDIO_SUPPORTED |
| 1257 | char msg[40]; |
| 1258 | |
| 1259 | png_snprintf(msg, 40, |
| 1260 | "invalid keyword character 0x%02X", (png_byte)*kp); |
| 1261 | png_warning(png_ptr, msg); |
| 1262 | #else |
| 1263 | png_warning(png_ptr, "invalid character in keyword"); |
| 1264 | #endif |
| 1265 | *dp = ' '; |
| 1266 | } |
| 1267 | else |
| 1268 | { |
| 1269 | *dp = *kp; |
| 1270 | } |
| 1271 | } |
| 1272 | *dp = '\0'; |
| 1273 | |
| 1274 | /* Remove any trailing white space. */ |
| 1275 | kp = *new_key + key_len - 1; |
| 1276 | if (*kp == ' ') |
| 1277 | { |
| 1278 | png_warning(png_ptr, "trailing spaces removed from keyword"); |
| 1279 | |
| 1280 | while (*kp == ' ') |
| 1281 | { |
| 1282 | *(kp--) = '\0'; |
| 1283 | key_len--; |
| 1284 | } |
| 1285 | } |
| 1286 | |
| 1287 | /* Remove any leading white space. */ |
| 1288 | kp = *new_key; |
| 1289 | if (*kp == ' ') |
| 1290 | { |
| 1291 | png_warning(png_ptr, "leading spaces removed from keyword"); |
| 1292 | |
| 1293 | while (*kp == ' ') |
| 1294 | { |
| 1295 | kp++; |
| 1296 | key_len--; |
| 1297 | } |
| 1298 | } |
| 1299 | |
| 1300 | png_debug1(2, "Checking for multiple internal spaces in '%s'", kp); |
| 1301 | |
| 1302 | /* Remove multiple internal spaces. */ |
| 1303 | for (kflag = 0, dp = *new_key; *kp != '\0'; kp++) |
| 1304 | { |
| 1305 | if (*kp == ' ' && kflag == 0) |
| 1306 | { |
| 1307 | *(dp++) = *kp; |
| 1308 | kflag = 1; |
| 1309 | } |
| 1310 | else if (*kp == ' ') |
| 1311 | { |
| 1312 | key_len--; |
| 1313 | kwarn=1; |
| 1314 | } |
| 1315 | else |
| 1316 | { |
| 1317 | *(dp++) = *kp; |
| 1318 | kflag = 0; |
| 1319 | } |
| 1320 | } |
| 1321 | *dp = '\0'; |
| 1322 | if (kwarn) |
| 1323 | png_warning(png_ptr, "extra interior spaces removed from keyword"); |
| 1324 | |
| 1325 | if (key_len == 0) |
| 1326 | { |
| 1327 | png_free(png_ptr, *new_key); |
| 1328 | png_warning(png_ptr, "Zero length keyword"); |
| 1329 | } |
| 1330 | |
| 1331 | if (key_len > 79) |
| 1332 | { |
| 1333 | png_warning(png_ptr, "keyword length must be 1 - 79 characters"); |
| 1334 | (*new_key)[79] = '\0'; |
| 1335 | key_len = 79; |
| 1336 | } |
| 1337 | |
| 1338 | return (key_len); |
| 1339 | } |
| 1340 | #endif |
| 1341 | |
| 1342 | #ifdef PNG_WRITE_tEXt_SUPPORTED |
| 1343 | /* Write a tEXt chunk */ |
| 1344 | void /* PRIVATE */ |
| 1345 | png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text, |
| 1346 | png_size_t text_len) |
| 1347 | { |
| 1348 | PNG_tEXt; |
| 1349 | png_size_t key_len; |
| 1350 | png_charp new_key; |
| 1351 | |
| 1352 | png_debug(1, "in png_write_tEXt"); |
| 1353 | |
| 1354 | if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0) |
| 1355 | return; |
| 1356 | |
| 1357 | if (text == NULL || *text == '\0') |
| 1358 | text_len = 0; |
| 1359 | else |
| 1360 | text_len = png_strlen(text); |
| 1361 | |
| 1362 | /* Make sure we include the 0 after the key */ |
| 1363 | png_write_chunk_start(png_ptr, (png_bytep)png_tEXt, |
| 1364 | (png_uint_32)(key_len + text_len + 1)); |
| 1365 | /* |
| 1366 | * We leave it to the application to meet PNG-1.0 requirements on the |
| 1367 | * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of |
| 1368 | * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. |
| 1369 | * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. |
| 1370 | */ |
| 1371 | png_write_chunk_data(png_ptr, (png_bytep)new_key, |
| 1372 | (png_size_t)(key_len + 1)); |
| 1373 | if (text_len) |
| 1374 | png_write_chunk_data(png_ptr, (png_bytep)text, (png_size_t)text_len); |
| 1375 | |
| 1376 | png_write_chunk_end(png_ptr); |
| 1377 | png_free(png_ptr, new_key); |
| 1378 | } |
| 1379 | #endif |
| 1380 | |
| 1381 | #ifdef PNG_WRITE_zTXt_SUPPORTED |
| 1382 | /* Write a compressed text chunk */ |
| 1383 | void /* PRIVATE */ |
| 1384 | png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text, |
| 1385 | png_size_t text_len, int compression) |
| 1386 | { |
| 1387 | PNG_zTXt; |
| 1388 | png_size_t key_len; |
| 1389 | char buf[1]; |
| 1390 | png_charp new_key; |
| 1391 | compression_state comp; |
| 1392 | |
| 1393 | png_debug(1, "in png_write_zTXt"); |
| 1394 | |
| 1395 | comp.num_output_ptr = 0; |
| 1396 | comp.max_output_ptr = 0; |
| 1397 | comp.output_ptr = NULL; |
| 1398 | comp.input = NULL; |
| 1399 | comp.input_len = 0; |
| 1400 | |
| 1401 | if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0) |
| 1402 | { |
| 1403 | png_free(png_ptr, new_key); |
| 1404 | return; |
| 1405 | } |
| 1406 | |
| 1407 | if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE) |
| 1408 | { |
| 1409 | png_write_tEXt(png_ptr, new_key, text, (png_size_t)0); |
| 1410 | png_free(png_ptr, new_key); |
| 1411 | return; |
| 1412 | } |
| 1413 | |
| 1414 | text_len = png_strlen(text); |
| 1415 | |
| 1416 | /* Compute the compressed data; do it now for the length */ |
| 1417 | text_len = png_text_compress(png_ptr, text, text_len, compression, |
| 1418 | &comp); |
| 1419 | |
| 1420 | /* Write start of chunk */ |
| 1421 | png_write_chunk_start(png_ptr, (png_bytep)png_zTXt, |
| 1422 | (png_uint_32)(key_len+text_len + 2)); |
| 1423 | /* Write key */ |
| 1424 | png_write_chunk_data(png_ptr, (png_bytep)new_key, |
| 1425 | (png_size_t)(key_len + 1)); |
| 1426 | png_free(png_ptr, new_key); |
| 1427 | |
| 1428 | buf[0] = (png_byte)compression; |
| 1429 | /* Write compression */ |
| 1430 | png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1); |
| 1431 | /* Write the compressed data */ |
| 1432 | png_write_compressed_data_out(png_ptr, &comp); |
| 1433 | |
| 1434 | /* Close the chunk */ |
| 1435 | png_write_chunk_end(png_ptr); |
| 1436 | } |
| 1437 | #endif |
| 1438 | |
| 1439 | #ifdef PNG_WRITE_iTXt_SUPPORTED |
| 1440 | /* Write an iTXt chunk */ |
| 1441 | void /* PRIVATE */ |
| 1442 | png_write_iTXt(png_structp png_ptr, int compression, png_charp key, |
| 1443 | png_charp lang, png_charp lang_key, png_charp text) |
| 1444 | { |
| 1445 | PNG_iTXt; |
| 1446 | png_size_t lang_len, key_len, lang_key_len, text_len; |
| 1447 | png_charp new_lang; |
| 1448 | png_charp new_key = NULL; |
| 1449 | png_byte cbuf[2]; |
| 1450 | compression_state comp; |
| 1451 | |
| 1452 | png_debug(1, "in png_write_iTXt"); |
| 1453 | |
| 1454 | comp.num_output_ptr = 0; |
| 1455 | comp.max_output_ptr = 0; |
| 1456 | comp.output_ptr = NULL; |
| 1457 | comp.input = NULL; |
| 1458 | |
| 1459 | if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0) |
| 1460 | return; |
| 1461 | |
| 1462 | if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0) |
| 1463 | { |
| 1464 | png_warning(png_ptr, "Empty language field in iTXt chunk"); |
| 1465 | new_lang = NULL; |
| 1466 | lang_len = 0; |
| 1467 | } |
| 1468 | |
| 1469 | if (lang_key == NULL) |
| 1470 | lang_key_len = 0; |
| 1471 | else |
| 1472 | lang_key_len = png_strlen(lang_key); |
| 1473 | |
| 1474 | if (text == NULL) |
| 1475 | text_len = 0; |
| 1476 | else |
| 1477 | text_len = png_strlen(text); |
| 1478 | |
| 1479 | /* Compute the compressed data; do it now for the length */ |
| 1480 | text_len = png_text_compress(png_ptr, text, text_len, compression-2, |
| 1481 | &comp); |
| 1482 | |
| 1483 | |
| 1484 | /* Make sure we include the compression flag, the compression byte, |
| 1485 | * and the NULs after the key, lang, and lang_key parts */ |
| 1486 | |
| 1487 | png_write_chunk_start(png_ptr, (png_bytep)png_iTXt, |
| 1488 | (png_uint_32)( |
| 1489 | 5 /* comp byte, comp flag, terminators for key, lang and lang_key */ |
| 1490 | + key_len |
| 1491 | + lang_len |
| 1492 | + lang_key_len |
| 1493 | + text_len)); |
| 1494 | |
| 1495 | /* We leave it to the application to meet PNG-1.0 requirements on the |
| 1496 | * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of |
| 1497 | * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. |
| 1498 | * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. |
| 1499 | */ |
| 1500 | png_write_chunk_data(png_ptr, (png_bytep)new_key, |
| 1501 | (png_size_t)(key_len + 1)); |
| 1502 | |
| 1503 | /* Set the compression flag */ |
| 1504 | if (compression == PNG_ITXT_COMPRESSION_NONE || \ |
| 1505 | compression == PNG_TEXT_COMPRESSION_NONE) |
| 1506 | cbuf[0] = 0; |
| 1507 | else /* compression == PNG_ITXT_COMPRESSION_zTXt */ |
| 1508 | cbuf[0] = 1; |
| 1509 | /* Set the compression method */ |
| 1510 | cbuf[1] = 0; |
| 1511 | png_write_chunk_data(png_ptr, cbuf, (png_size_t)2); |
| 1512 | |
| 1513 | cbuf[0] = 0; |
| 1514 | png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf), |
| 1515 | (png_size_t)(lang_len + 1)); |
| 1516 | png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf), |
| 1517 | (png_size_t)(lang_key_len + 1)); |
| 1518 | png_write_compressed_data_out(png_ptr, &comp); |
| 1519 | |
| 1520 | png_write_chunk_end(png_ptr); |
| 1521 | png_free(png_ptr, new_key); |
| 1522 | png_free(png_ptr, new_lang); |
| 1523 | } |
| 1524 | #endif |
| 1525 | |
| 1526 | #ifdef PNG_WRITE_oFFs_SUPPORTED |
| 1527 | /* Write the oFFs chunk */ |
| 1528 | void /* PRIVATE */ |
| 1529 | png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, |
| 1530 | int unit_type) |
| 1531 | { |
| 1532 | PNG_oFFs; |
| 1533 | png_byte buf[9]; |
| 1534 | |
| 1535 | png_debug(1, "in png_write_oFFs"); |
| 1536 | |
| 1537 | if (unit_type >= PNG_OFFSET_LAST) |
| 1538 | png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); |
| 1539 | |
| 1540 | png_save_int_32(buf, x_offset); |
| 1541 | png_save_int_32(buf + 4, y_offset); |
| 1542 | buf[8] = (png_byte)unit_type; |
| 1543 | |
| 1544 | png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9); |
| 1545 | } |
| 1546 | #endif |
| 1547 | #ifdef PNG_WRITE_pCAL_SUPPORTED |
| 1548 | /* Write the pCAL chunk (described in the PNG extensions document) */ |
| 1549 | void /* PRIVATE */ |
| 1550 | png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, |
| 1551 | png_int_32 X1, int type, int nparams, png_charp units, png_charpp params) |
| 1552 | { |
| 1553 | PNG_pCAL; |
| 1554 | png_size_t purpose_len, units_len, total_len; |
| 1555 | png_uint_32p params_len; |
| 1556 | png_byte buf[10]; |
| 1557 | png_charp new_purpose; |
| 1558 | int i; |
| 1559 | |
| 1560 | png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); |
| 1561 | |
| 1562 | if (type >= PNG_EQUATION_LAST) |
| 1563 | png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); |
| 1564 | |
| 1565 | purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1; |
| 1566 | png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); |
| 1567 | units_len = png_strlen(units) + (nparams == 0 ? 0 : 1); |
| 1568 | png_debug1(3, "pCAL units length = %d", (int)units_len); |
| 1569 | total_len = purpose_len + units_len + 10; |
| 1570 | |
| 1571 | params_len = (png_uint_32p)png_malloc(png_ptr, |
| 1572 | (png_alloc_size_t)(nparams * png_sizeof(png_uint_32))); |
| 1573 | |
| 1574 | /* Find the length of each parameter, making sure we don't count the |
| 1575 | null terminator for the last parameter. */ |
| 1576 | for (i = 0; i < nparams; i++) |
| 1577 | { |
| 1578 | params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1); |
| 1579 | png_debug2(3, "pCAL parameter %d length = %lu", i, |
| 1580 | (unsigned long) params_len[i]); |
| 1581 | total_len += (png_size_t)params_len[i]; |
| 1582 | } |
| 1583 | |
| 1584 | png_debug1(3, "pCAL total length = %d", (int)total_len); |
| 1585 | png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len); |
| 1586 | png_write_chunk_data(png_ptr, (png_bytep)new_purpose, |
| 1587 | (png_size_t)purpose_len); |
| 1588 | png_save_int_32(buf, X0); |
| 1589 | png_save_int_32(buf + 4, X1); |
| 1590 | buf[8] = (png_byte)type; |
| 1591 | buf[9] = (png_byte)nparams; |
| 1592 | png_write_chunk_data(png_ptr, buf, (png_size_t)10); |
| 1593 | png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len); |
| 1594 | |
| 1595 | png_free(png_ptr, new_purpose); |
| 1596 | |
| 1597 | for (i = 0; i < nparams; i++) |
| 1598 | { |
| 1599 | png_write_chunk_data(png_ptr, (png_bytep)params[i], |
| 1600 | (png_size_t)params_len[i]); |
| 1601 | } |
| 1602 | |
| 1603 | png_free(png_ptr, params_len); |
| 1604 | png_write_chunk_end(png_ptr); |
| 1605 | } |
| 1606 | #endif |
| 1607 | |
| 1608 | #ifdef PNG_WRITE_sCAL_SUPPORTED |
| 1609 | /* Write the sCAL chunk */ |
| 1610 | #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED) |
| 1611 | void /* PRIVATE */ |
| 1612 | png_write_sCAL(png_structp png_ptr, int unit, double width, double height) |
| 1613 | { |
| 1614 | PNG_sCAL; |
| 1615 | char buf[64]; |
| 1616 | png_size_t total_len; |
| 1617 | |
| 1618 | png_debug(1, "in png_write_sCAL"); |
| 1619 | |
| 1620 | buf[0] = (char)unit; |
| 1621 | png_snprintf(buf + 1, 63, "%12.12e", width); |
| 1622 | total_len = 1 + png_strlen(buf + 1) + 1; |
| 1623 | png_snprintf(buf + total_len, 64-total_len, "%12.12e", height); |
| 1624 | total_len += png_strlen(buf + total_len); |
| 1625 | |
| 1626 | png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); |
| 1627 | png_write_chunk(png_ptr, (png_bytep)png_sCAL, (png_bytep)buf, total_len); |
| 1628 | } |
| 1629 | #else |
| 1630 | #ifdef PNG_FIXED_POINT_SUPPORTED |
| 1631 | void /* PRIVATE */ |
| 1632 | png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width, |
| 1633 | png_charp height) |
| 1634 | { |
| 1635 | PNG_sCAL; |
| 1636 | png_byte buf[64]; |
| 1637 | png_size_t wlen, hlen, total_len; |
| 1638 | |
| 1639 | png_debug(1, "in png_write_sCAL_s"); |
| 1640 | |
| 1641 | wlen = png_strlen(width); |
| 1642 | hlen = png_strlen(height); |
| 1643 | total_len = wlen + hlen + 2; |
| 1644 | if (total_len > 64) |
| 1645 | { |
| 1646 | png_warning(png_ptr, "Can't write sCAL (buffer too small)"); |
| 1647 | return; |
| 1648 | } |
| 1649 | |
| 1650 | buf[0] = (png_byte)unit; |
| 1651 | png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ |
| 1652 | png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ |
| 1653 | |
| 1654 | png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); |
| 1655 | png_write_chunk(png_ptr, (png_bytep)png_sCAL, buf, total_len); |
| 1656 | } |
| 1657 | #endif |
| 1658 | #endif |
| 1659 | #endif |
| 1660 | |
| 1661 | #ifdef PNG_WRITE_pHYs_SUPPORTED |
| 1662 | /* Write the pHYs chunk */ |
| 1663 | void /* PRIVATE */ |
| 1664 | png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, |
| 1665 | png_uint_32 y_pixels_per_unit, |
| 1666 | int unit_type) |
| 1667 | { |
| 1668 | PNG_pHYs; |
| 1669 | png_byte buf[9]; |
| 1670 | |
| 1671 | png_debug(1, "in png_write_pHYs"); |
| 1672 | |
| 1673 | if (unit_type >= PNG_RESOLUTION_LAST) |
| 1674 | png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); |
| 1675 | |
| 1676 | png_save_uint_32(buf, x_pixels_per_unit); |
| 1677 | png_save_uint_32(buf + 4, y_pixels_per_unit); |
| 1678 | buf[8] = (png_byte)unit_type; |
| 1679 | |
| 1680 | png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9); |
| 1681 | } |
| 1682 | #endif |
| 1683 | |
| 1684 | #ifdef PNG_WRITE_tIME_SUPPORTED |
| 1685 | /* Write the tIME chunk. Use either png_convert_from_struct_tm() |
| 1686 | * or png_convert_from_time_t(), or fill in the structure yourself. |
| 1687 | */ |
| 1688 | void /* PRIVATE */ |
| 1689 | png_write_tIME(png_structp png_ptr, png_timep mod_time) |
| 1690 | { |
| 1691 | PNG_tIME; |
| 1692 | png_byte buf[7]; |
| 1693 | |
| 1694 | png_debug(1, "in png_write_tIME"); |
| 1695 | |
| 1696 | if (mod_time->month > 12 || mod_time->month < 1 || |
| 1697 | mod_time->day > 31 || mod_time->day < 1 || |
| 1698 | mod_time->hour > 23 || mod_time->second > 60) |
| 1699 | { |
| 1700 | png_warning(png_ptr, "Invalid time specified for tIME chunk"); |
| 1701 | return; |
| 1702 | } |
| 1703 | |
| 1704 | png_save_uint_16(buf, mod_time->year); |
| 1705 | buf[2] = mod_time->month; |
| 1706 | buf[3] = mod_time->day; |
| 1707 | buf[4] = mod_time->hour; |
| 1708 | buf[5] = mod_time->minute; |
| 1709 | buf[6] = mod_time->second; |
| 1710 | |
| 1711 | png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7); |
| 1712 | } |
| 1713 | #endif |
| 1714 | |
| 1715 | /* Initializes the row writing capability of libpng */ |
| 1716 | void /* PRIVATE */ |
| 1717 | png_write_start_row(png_structp png_ptr) |
| 1718 | { |
| 1719 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| 1720 | /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
| 1721 | |
| 1722 | /* Start of interlace block */ |
| 1723 | int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; |
| 1724 | |
| 1725 | /* Offset to next interlace block */ |
| 1726 | int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
| 1727 | |
| 1728 | /* Start of interlace block in the y direction */ |
| 1729 | int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; |
| 1730 | |
| 1731 | /* Offset to next interlace block in the y direction */ |
| 1732 | int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; |
| 1733 | #endif |
| 1734 | |
| 1735 | png_size_t buf_size; |
| 1736 | |
| 1737 | png_debug(1, "in png_write_start_row"); |
| 1738 | |
| 1739 | buf_size = (png_size_t)(PNG_ROWBYTES( |
| 1740 | png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1); |
| 1741 | |
| 1742 | /* Set up row buffer */ |
| 1743 | png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, |
| 1744 | (png_alloc_size_t)buf_size); |
| 1745 | png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; |
| 1746 | |
| 1747 | #ifdef PNG_WRITE_FILTER_SUPPORTED |
| 1748 | /* Set up filtering buffer, if using this filter */ |
| 1749 | if (png_ptr->do_filter & PNG_FILTER_SUB) |
| 1750 | { |
| 1751 | png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, |
| 1752 | (png_alloc_size_t)(png_ptr->rowbytes + 1)); |
| 1753 | png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; |
| 1754 | } |
| 1755 | |
| 1756 | /* We only need to keep the previous row if we are using one of these. */ |
| 1757 | if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) |
| 1758 | { |
| 1759 | /* Set up previous row buffer */ |
| 1760 | png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, |
| 1761 | (png_alloc_size_t)buf_size); |
| 1762 | |
| 1763 | if (png_ptr->do_filter & PNG_FILTER_UP) |
| 1764 | { |
| 1765 | png_ptr->up_row = (png_bytep)png_malloc(png_ptr, |
| 1766 | (png_size_t)(png_ptr->rowbytes + 1)); |
| 1767 | png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; |
| 1768 | } |
| 1769 | |
| 1770 | if (png_ptr->do_filter & PNG_FILTER_AVG) |
| 1771 | { |
| 1772 | png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, |
| 1773 | (png_alloc_size_t)(png_ptr->rowbytes + 1)); |
| 1774 | png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; |
| 1775 | } |
| 1776 | |
| 1777 | if (png_ptr->do_filter & PNG_FILTER_PAETH) |
| 1778 | { |
| 1779 | png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, |
| 1780 | (png_size_t)(png_ptr->rowbytes + 1)); |
| 1781 | png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; |
| 1782 | } |
| 1783 | } |
| 1784 | #endif /* PNG_WRITE_FILTER_SUPPORTED */ |
| 1785 | |
| 1786 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| 1787 | /* If interlaced, we need to set up width and height of pass */ |
| 1788 | if (png_ptr->interlaced) |
| 1789 | { |
| 1790 | if (!(png_ptr->transformations & PNG_INTERLACE)) |
| 1791 | { |
| 1792 | png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - |
| 1793 | png_pass_ystart[0]) / png_pass_yinc[0]; |
| 1794 | png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - |
| 1795 | png_pass_start[0]) / png_pass_inc[0]; |
| 1796 | } |
| 1797 | else |
| 1798 | { |
| 1799 | png_ptr->num_rows = png_ptr->height; |
| 1800 | png_ptr->usr_width = png_ptr->width; |
| 1801 | } |
| 1802 | } |
| 1803 | else |
| 1804 | #endif |
| 1805 | { |
| 1806 | png_ptr->num_rows = png_ptr->height; |
| 1807 | png_ptr->usr_width = png_ptr->width; |
| 1808 | } |
| 1809 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| 1810 | png_ptr->zstream.next_out = png_ptr->zbuf; |
| 1811 | } |
| 1812 | |
| 1813 | /* Internal use only. Called when finished processing a row of data. */ |
| 1814 | void /* PRIVATE */ |
| 1815 | png_write_finish_row(png_structp png_ptr) |
| 1816 | { |
| 1817 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| 1818 | /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
| 1819 | |
| 1820 | /* Start of interlace block */ |
| 1821 | int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; |
| 1822 | |
| 1823 | /* Offset to next interlace block */ |
| 1824 | int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
| 1825 | |
| 1826 | /* Start of interlace block in the y direction */ |
| 1827 | int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; |
| 1828 | |
| 1829 | /* Offset to next interlace block in the y direction */ |
| 1830 | int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; |
| 1831 | #endif |
| 1832 | |
| 1833 | int ret; |
| 1834 | |
| 1835 | png_debug(1, "in png_write_finish_row"); |
| 1836 | |
| 1837 | /* Next row */ |
| 1838 | png_ptr->row_number++; |
| 1839 | |
| 1840 | /* See if we are done */ |
| 1841 | if (png_ptr->row_number < png_ptr->num_rows) |
| 1842 | return; |
| 1843 | |
| 1844 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| 1845 | /* If interlaced, go to next pass */ |
| 1846 | if (png_ptr->interlaced) |
| 1847 | { |
| 1848 | png_ptr->row_number = 0; |
| 1849 | if (png_ptr->transformations & PNG_INTERLACE) |
| 1850 | { |
| 1851 | png_ptr->pass++; |
| 1852 | } |
| 1853 | else |
| 1854 | { |
| 1855 | /* Loop until we find a non-zero width or height pass */ |
| 1856 | do |
| 1857 | { |
| 1858 | png_ptr->pass++; |
| 1859 | if (png_ptr->pass >= 7) |
| 1860 | break; |
| 1861 | png_ptr->usr_width = (png_ptr->width + |
| 1862 | png_pass_inc[png_ptr->pass] - 1 - |
| 1863 | png_pass_start[png_ptr->pass]) / |
| 1864 | png_pass_inc[png_ptr->pass]; |
| 1865 | png_ptr->num_rows = (png_ptr->height + |
| 1866 | png_pass_yinc[png_ptr->pass] - 1 - |
| 1867 | png_pass_ystart[png_ptr->pass]) / |
| 1868 | png_pass_yinc[png_ptr->pass]; |
| 1869 | if (png_ptr->transformations & PNG_INTERLACE) |
| 1870 | break; |
| 1871 | } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); |
| 1872 | |
| 1873 | } |
| 1874 | |
| 1875 | /* Reset the row above the image for the next pass */ |
| 1876 | if (png_ptr->pass < 7) |
| 1877 | { |
| 1878 | if (png_ptr->prev_row != NULL) |
| 1879 | png_memset(png_ptr->prev_row, 0, |
| 1880 | (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels* |
| 1881 | png_ptr->usr_bit_depth, png_ptr->width)) + 1); |
| 1882 | return; |
| 1883 | } |
| 1884 | } |
| 1885 | #endif |
| 1886 | |
| 1887 | /* If we get here, we've just written the last row, so we need |
| 1888 | to flush the compressor */ |
| 1889 | do |
| 1890 | { |
| 1891 | /* Tell the compressor we are done */ |
| 1892 | ret = deflate(&png_ptr->zstream, Z_FINISH); |
| 1893 | /* Check for an error */ |
| 1894 | if (ret == Z_OK) |
| 1895 | { |
| 1896 | /* Check to see if we need more room */ |
| 1897 | if (!(png_ptr->zstream.avail_out)) |
| 1898 | { |
| 1899 | png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); |
| 1900 | png_ptr->zstream.next_out = png_ptr->zbuf; |
| 1901 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| 1902 | } |
| 1903 | } |
| 1904 | else if (ret != Z_STREAM_END) |
| 1905 | { |
| 1906 | if (png_ptr->zstream.msg != NULL) |
| 1907 | png_error(png_ptr, png_ptr->zstream.msg); |
| 1908 | else |
| 1909 | png_error(png_ptr, "zlib error"); |
| 1910 | } |
| 1911 | } while (ret != Z_STREAM_END); |
| 1912 | |
| 1913 | /* Write any extra space */ |
| 1914 | if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) |
| 1915 | { |
| 1916 | png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size - |
| 1917 | png_ptr->zstream.avail_out); |
| 1918 | } |
| 1919 | |
| 1920 | deflateReset(&png_ptr->zstream); |
| 1921 | png_ptr->zstream.data_type = Z_BINARY; |
| 1922 | } |
| 1923 | |
| 1924 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
| 1925 | /* Pick out the correct pixels for the interlace pass. |
| 1926 | * The basic idea here is to go through the row with a source |
| 1927 | * pointer and a destination pointer (sp and dp), and copy the |
| 1928 | * correct pixels for the pass. As the row gets compacted, |
| 1929 | * sp will always be >= dp, so we should never overwrite anything. |
| 1930 | * See the default: case for the easiest code to understand. |
| 1931 | */ |
| 1932 | void /* PRIVATE */ |
| 1933 | png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) |
| 1934 | { |
| 1935 | /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
| 1936 | |
| 1937 | /* Start of interlace block */ |
| 1938 | int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; |
| 1939 | |
| 1940 | /* Offset to next interlace block */ |
| 1941 | int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
| 1942 | |
| 1943 | png_debug(1, "in png_do_write_interlace"); |
| 1944 | |
| 1945 | /* We don't have to do anything on the last pass (6) */ |
| 1946 | if (pass < 6) |
| 1947 | { |
| 1948 | /* Each pixel depth is handled separately */ |
| 1949 | switch (row_info->pixel_depth) |
| 1950 | { |
| 1951 | case 1: |
| 1952 | { |
| 1953 | png_bytep sp; |
| 1954 | png_bytep dp; |
| 1955 | int shift; |
| 1956 | int d; |
| 1957 | int value; |
| 1958 | png_uint_32 i; |
| 1959 | png_uint_32 row_width = row_info->width; |
| 1960 | |
| 1961 | dp = row; |
| 1962 | d = 0; |
| 1963 | shift = 7; |
| 1964 | for (i = png_pass_start[pass]; i < row_width; |
| 1965 | i += png_pass_inc[pass]) |
| 1966 | { |
| 1967 | sp = row + (png_size_t)(i >> 3); |
| 1968 | value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01; |
| 1969 | d |= (value << shift); |
| 1970 | |
| 1971 | if (shift == 0) |
| 1972 | { |
| 1973 | shift = 7; |
| 1974 | *dp++ = (png_byte)d; |
| 1975 | d = 0; |
| 1976 | } |
| 1977 | else |
| 1978 | shift--; |
| 1979 | |
| 1980 | } |
| 1981 | if (shift != 7) |
| 1982 | *dp = (png_byte)d; |
| 1983 | break; |
| 1984 | } |
| 1985 | case 2: |
| 1986 | { |
| 1987 | png_bytep sp; |
| 1988 | png_bytep dp; |
| 1989 | int shift; |
| 1990 | int d; |
| 1991 | int value; |
| 1992 | png_uint_32 i; |
| 1993 | png_uint_32 row_width = row_info->width; |
| 1994 | |
| 1995 | dp = row; |
| 1996 | shift = 6; |
| 1997 | d = 0; |
| 1998 | for (i = png_pass_start[pass]; i < row_width; |
| 1999 | i += png_pass_inc[pass]) |
| 2000 | { |
| 2001 | sp = row + (png_size_t)(i >> 2); |
| 2002 | value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03; |
| 2003 | d |= (value << shift); |
| 2004 | |
| 2005 | if (shift == 0) |
| 2006 | { |
| 2007 | shift = 6; |
| 2008 | *dp++ = (png_byte)d; |
| 2009 | d = 0; |
| 2010 | } |
| 2011 | else |
| 2012 | shift -= 2; |
| 2013 | } |
| 2014 | if (shift != 6) |
| 2015 | *dp = (png_byte)d; |
| 2016 | break; |
| 2017 | } |
| 2018 | case 4: |
| 2019 | { |
| 2020 | png_bytep sp; |
| 2021 | png_bytep dp; |
| 2022 | int shift; |
| 2023 | int d; |
| 2024 | int value; |
| 2025 | png_uint_32 i; |
| 2026 | png_uint_32 row_width = row_info->width; |
| 2027 | |
| 2028 | dp = row; |
| 2029 | shift = 4; |
| 2030 | d = 0; |
| 2031 | for (i = png_pass_start[pass]; i < row_width; |
| 2032 | i += png_pass_inc[pass]) |
| 2033 | { |
| 2034 | sp = row + (png_size_t)(i >> 1); |
| 2035 | value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f; |
| 2036 | d |= (value << shift); |
| 2037 | |
| 2038 | if (shift == 0) |
| 2039 | { |
| 2040 | shift = 4; |
| 2041 | *dp++ = (png_byte)d; |
| 2042 | d = 0; |
| 2043 | } |
| 2044 | else |
| 2045 | shift -= 4; |
| 2046 | } |
| 2047 | if (shift != 4) |
| 2048 | *dp = (png_byte)d; |
| 2049 | break; |
| 2050 | } |
| 2051 | default: |
| 2052 | { |
| 2053 | png_bytep sp; |
| 2054 | png_bytep dp; |
| 2055 | png_uint_32 i; |
| 2056 | png_uint_32 row_width = row_info->width; |
| 2057 | png_size_t pixel_bytes; |
| 2058 | |
| 2059 | /* Start at the beginning */ |
| 2060 | dp = row; |
| 2061 | /* Find out how many bytes each pixel takes up */ |
| 2062 | pixel_bytes = (row_info->pixel_depth >> 3); |
| 2063 | /* Loop through the row, only looking at the pixels that |
| 2064 | matter */ |
| 2065 | for (i = png_pass_start[pass]; i < row_width; |
| 2066 | i += png_pass_inc[pass]) |
| 2067 | { |
| 2068 | /* Find out where the original pixel is */ |
| 2069 | sp = row + (png_size_t)i * pixel_bytes; |
| 2070 | /* Move the pixel */ |
| 2071 | if (dp != sp) |
| 2072 | png_memcpy(dp, sp, pixel_bytes); |
| 2073 | /* Next pixel */ |
| 2074 | dp += pixel_bytes; |
| 2075 | } |
| 2076 | break; |
| 2077 | } |
| 2078 | } |
| 2079 | /* Set new row width */ |
| 2080 | row_info->width = (row_info->width + |
| 2081 | png_pass_inc[pass] - 1 - |
| 2082 | png_pass_start[pass]) / |
| 2083 | png_pass_inc[pass]; |
| 2084 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, |
| 2085 | row_info->width); |
| 2086 | } |
| 2087 | } |
| 2088 | #endif |
| 2089 | |
| 2090 | /* This filters the row, chooses which filter to use, if it has not already |
| 2091 | * been specified by the application, and then writes the row out with the |
| 2092 | * chosen filter. |
| 2093 | */ |
| 2094 | #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1) |
| 2095 | #define PNG_HISHIFT 10 |
| 2096 | #define PNG_LOMASK ((png_uint_32)0xffffL) |
| 2097 | #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT)) |
| 2098 | void /* PRIVATE */ |
| 2099 | png_write_find_filter(png_structp png_ptr, png_row_infop row_info) |
| 2100 | { |
| 2101 | png_bytep best_row; |
| 2102 | #ifdef PNG_WRITE_FILTER_SUPPORTED |
| 2103 | png_bytep prev_row, row_buf; |
| 2104 | png_uint_32 mins, bpp; |
| 2105 | png_byte filter_to_do = png_ptr->do_filter; |
| 2106 | png_uint_32 row_bytes = row_info->rowbytes; |
| 2107 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2108 | int num_p_filters = (int)png_ptr->num_prev_filters; |
| 2109 | #endif |
| 2110 | |
| 2111 | png_debug(1, "in png_write_find_filter"); |
| 2112 | |
| 2113 | #ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2114 | if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS) |
| 2115 | { |
| 2116 | /* These will never be selected so we need not test them. */ |
| 2117 | filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH); |
| 2118 | } |
| 2119 | #endif |
| 2120 | |
| 2121 | /* Find out how many bytes offset each pixel is */ |
| 2122 | bpp = (row_info->pixel_depth + 7) >> 3; |
| 2123 | |
| 2124 | prev_row = png_ptr->prev_row; |
| 2125 | #endif |
| 2126 | best_row = png_ptr->row_buf; |
| 2127 | #ifdef PNG_WRITE_FILTER_SUPPORTED |
| 2128 | row_buf = best_row; |
| 2129 | mins = PNG_MAXSUM; |
| 2130 | |
| 2131 | /* The prediction method we use is to find which method provides the |
| 2132 | * smallest value when summing the absolute values of the distances |
| 2133 | * from zero, using anything >= 128 as negative numbers. This is known |
| 2134 | * as the "minimum sum of absolute differences" heuristic. Other |
| 2135 | * heuristics are the "weighted minimum sum of absolute differences" |
| 2136 | * (experimental and can in theory improve compression), and the "zlib |
| 2137 | * predictive" method (not implemented yet), which does test compressions |
| 2138 | * of lines using different filter methods, and then chooses the |
| 2139 | * (series of) filter(s) that give minimum compressed data size (VERY |
| 2140 | * computationally expensive). |
| 2141 | * |
| 2142 | * GRR 980525: consider also |
| 2143 | * (1) minimum sum of absolute differences from running average (i.e., |
| 2144 | * keep running sum of non-absolute differences & count of bytes) |
| 2145 | * [track dispersion, too? restart average if dispersion too large?] |
| 2146 | * (1b) minimum sum of absolute differences from sliding average, probably |
| 2147 | * with window size <= deflate window (usually 32K) |
| 2148 | * (2) minimum sum of squared differences from zero or running average |
| 2149 | * (i.e., ~ root-mean-square approach) |
| 2150 | */ |
| 2151 | |
| 2152 | |
| 2153 | /* We don't need to test the 'no filter' case if this is the only filter |
| 2154 | * that has been chosen, as it doesn't actually do anything to the data. |
| 2155 | */ |
| 2156 | if ((filter_to_do & PNG_FILTER_NONE) && |
| 2157 | filter_to_do != PNG_FILTER_NONE) |
| 2158 | { |
| 2159 | png_bytep rp; |
| 2160 | png_uint_32 sum = 0; |
| 2161 | png_uint_32 i; |
| 2162 | int v; |
| 2163 | |
| 2164 | for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) |
| 2165 | { |
| 2166 | v = *rp; |
| 2167 | sum += (v < 128) ? v : 256 - v; |
| 2168 | } |
| 2169 | |
| 2170 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2171 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
| 2172 | { |
| 2173 | png_uint_32 sumhi, sumlo; |
| 2174 | int j; |
| 2175 | sumlo = sum & PNG_LOMASK; |
| 2176 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */ |
| 2177 | |
| 2178 | /* Reduce the sum if we match any of the previous rows */ |
| 2179 | for (j = 0; j < num_p_filters; j++) |
| 2180 | { |
| 2181 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) |
| 2182 | { |
| 2183 | sumlo = (sumlo * png_ptr->filter_weights[j]) >> |
| 2184 | PNG_WEIGHT_SHIFT; |
| 2185 | sumhi = (sumhi * png_ptr->filter_weights[j]) >> |
| 2186 | PNG_WEIGHT_SHIFT; |
| 2187 | } |
| 2188 | } |
| 2189 | |
| 2190 | /* Factor in the cost of this filter (this is here for completeness, |
| 2191 | * but it makes no sense to have a "cost" for the NONE filter, as |
| 2192 | * it has the minimum possible computational cost - none). |
| 2193 | */ |
| 2194 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> |
| 2195 | PNG_COST_SHIFT; |
| 2196 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> |
| 2197 | PNG_COST_SHIFT; |
| 2198 | |
| 2199 | if (sumhi > PNG_HIMASK) |
| 2200 | sum = PNG_MAXSUM; |
| 2201 | else |
| 2202 | sum = (sumhi << PNG_HISHIFT) + sumlo; |
| 2203 | } |
| 2204 | #endif |
| 2205 | mins = sum; |
| 2206 | } |
| 2207 | |
| 2208 | /* Sub filter */ |
| 2209 | if (filter_to_do == PNG_FILTER_SUB) |
| 2210 | /* It's the only filter so no testing is needed */ |
| 2211 | { |
| 2212 | png_bytep rp, lp, dp; |
| 2213 | png_uint_32 i; |
| 2214 | for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; |
| 2215 | i++, rp++, dp++) |
| 2216 | { |
| 2217 | *dp = *rp; |
| 2218 | } |
| 2219 | for (lp = row_buf + 1; i < row_bytes; |
| 2220 | i++, rp++, lp++, dp++) |
| 2221 | { |
| 2222 | *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); |
| 2223 | } |
| 2224 | best_row = png_ptr->sub_row; |
| 2225 | } |
| 2226 | |
| 2227 | else if (filter_to_do & PNG_FILTER_SUB) |
| 2228 | { |
| 2229 | png_bytep rp, dp, lp; |
| 2230 | png_uint_32 sum = 0, lmins = mins; |
| 2231 | png_uint_32 i; |
| 2232 | int v; |
| 2233 | |
| 2234 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2235 | /* We temporarily increase the "minimum sum" by the factor we |
| 2236 | * would reduce the sum of this filter, so that we can do the |
| 2237 | * early exit comparison without scaling the sum each time. |
| 2238 | */ |
| 2239 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
| 2240 | { |
| 2241 | int j; |
| 2242 | png_uint_32 lmhi, lmlo; |
| 2243 | lmlo = lmins & PNG_LOMASK; |
| 2244 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; |
| 2245 | |
| 2246 | for (j = 0; j < num_p_filters; j++) |
| 2247 | { |
| 2248 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) |
| 2249 | { |
| 2250 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> |
| 2251 | PNG_WEIGHT_SHIFT; |
| 2252 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> |
| 2253 | PNG_WEIGHT_SHIFT; |
| 2254 | } |
| 2255 | } |
| 2256 | |
| 2257 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> |
| 2258 | PNG_COST_SHIFT; |
| 2259 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> |
| 2260 | PNG_COST_SHIFT; |
| 2261 | |
| 2262 | if (lmhi > PNG_HIMASK) |
| 2263 | lmins = PNG_MAXSUM; |
| 2264 | else |
| 2265 | lmins = (lmhi << PNG_HISHIFT) + lmlo; |
| 2266 | } |
| 2267 | #endif |
| 2268 | |
| 2269 | for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; |
| 2270 | i++, rp++, dp++) |
| 2271 | { |
| 2272 | v = *dp = *rp; |
| 2273 | |
| 2274 | sum += (v < 128) ? v : 256 - v; |
| 2275 | } |
| 2276 | for (lp = row_buf + 1; i < row_bytes; |
| 2277 | i++, rp++, lp++, dp++) |
| 2278 | { |
| 2279 | v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); |
| 2280 | |
| 2281 | sum += (v < 128) ? v : 256 - v; |
| 2282 | |
| 2283 | if (sum > lmins) /* We are already worse, don't continue. */ |
| 2284 | break; |
| 2285 | } |
| 2286 | |
| 2287 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2288 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
| 2289 | { |
| 2290 | int j; |
| 2291 | png_uint_32 sumhi, sumlo; |
| 2292 | sumlo = sum & PNG_LOMASK; |
| 2293 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; |
| 2294 | |
| 2295 | for (j = 0; j < num_p_filters; j++) |
| 2296 | { |
| 2297 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) |
| 2298 | { |
| 2299 | sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >> |
| 2300 | PNG_WEIGHT_SHIFT; |
| 2301 | sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >> |
| 2302 | PNG_WEIGHT_SHIFT; |
| 2303 | } |
| 2304 | } |
| 2305 | |
| 2306 | sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> |
| 2307 | PNG_COST_SHIFT; |
| 2308 | sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> |
| 2309 | PNG_COST_SHIFT; |
| 2310 | |
| 2311 | if (sumhi > PNG_HIMASK) |
| 2312 | sum = PNG_MAXSUM; |
| 2313 | else |
| 2314 | sum = (sumhi << PNG_HISHIFT) + sumlo; |
| 2315 | } |
| 2316 | #endif |
| 2317 | |
| 2318 | if (sum < mins) |
| 2319 | { |
| 2320 | mins = sum; |
| 2321 | best_row = png_ptr->sub_row; |
| 2322 | } |
| 2323 | } |
| 2324 | |
| 2325 | /* Up filter */ |
| 2326 | if (filter_to_do == PNG_FILTER_UP) |
| 2327 | { |
| 2328 | png_bytep rp, dp, pp; |
| 2329 | png_uint_32 i; |
| 2330 | |
| 2331 | for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, |
| 2332 | pp = prev_row + 1; i < row_bytes; |
| 2333 | i++, rp++, pp++, dp++) |
| 2334 | { |
| 2335 | *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); |
| 2336 | } |
| 2337 | best_row = png_ptr->up_row; |
| 2338 | } |
| 2339 | |
| 2340 | else if (filter_to_do & PNG_FILTER_UP) |
| 2341 | { |
| 2342 | png_bytep rp, dp, pp; |
| 2343 | png_uint_32 sum = 0, lmins = mins; |
| 2344 | png_uint_32 i; |
| 2345 | int v; |
| 2346 | |
| 2347 | |
| 2348 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2349 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
| 2350 | { |
| 2351 | int j; |
| 2352 | png_uint_32 lmhi, lmlo; |
| 2353 | lmlo = lmins & PNG_LOMASK; |
| 2354 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; |
| 2355 | |
| 2356 | for (j = 0; j < num_p_filters; j++) |
| 2357 | { |
| 2358 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) |
| 2359 | { |
| 2360 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> |
| 2361 | PNG_WEIGHT_SHIFT; |
| 2362 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> |
| 2363 | PNG_WEIGHT_SHIFT; |
| 2364 | } |
| 2365 | } |
| 2366 | |
| 2367 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> |
| 2368 | PNG_COST_SHIFT; |
| 2369 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> |
| 2370 | PNG_COST_SHIFT; |
| 2371 | |
| 2372 | if (lmhi > PNG_HIMASK) |
| 2373 | lmins = PNG_MAXSUM; |
| 2374 | else |
| 2375 | lmins = (lmhi << PNG_HISHIFT) + lmlo; |
| 2376 | } |
| 2377 | #endif |
| 2378 | |
| 2379 | for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, |
| 2380 | pp = prev_row + 1; i < row_bytes; i++) |
| 2381 | { |
| 2382 | v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); |
| 2383 | |
| 2384 | sum += (v < 128) ? v : 256 - v; |
| 2385 | |
| 2386 | if (sum > lmins) /* We are already worse, don't continue. */ |
| 2387 | break; |
| 2388 | } |
| 2389 | |
| 2390 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2391 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
| 2392 | { |
| 2393 | int j; |
| 2394 | png_uint_32 sumhi, sumlo; |
| 2395 | sumlo = sum & PNG_LOMASK; |
| 2396 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; |
| 2397 | |
| 2398 | for (j = 0; j < num_p_filters; j++) |
| 2399 | { |
| 2400 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) |
| 2401 | { |
| 2402 | sumlo = (sumlo * png_ptr->filter_weights[j]) >> |
| 2403 | PNG_WEIGHT_SHIFT; |
| 2404 | sumhi = (sumhi * png_ptr->filter_weights[j]) >> |
| 2405 | PNG_WEIGHT_SHIFT; |
| 2406 | } |
| 2407 | } |
| 2408 | |
| 2409 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> |
| 2410 | PNG_COST_SHIFT; |
| 2411 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> |
| 2412 | PNG_COST_SHIFT; |
| 2413 | |
| 2414 | if (sumhi > PNG_HIMASK) |
| 2415 | sum = PNG_MAXSUM; |
| 2416 | else |
| 2417 | sum = (sumhi << PNG_HISHIFT) + sumlo; |
| 2418 | } |
| 2419 | #endif |
| 2420 | |
| 2421 | if (sum < mins) |
| 2422 | { |
| 2423 | mins = sum; |
| 2424 | best_row = png_ptr->up_row; |
| 2425 | } |
| 2426 | } |
| 2427 | |
| 2428 | /* Avg filter */ |
| 2429 | if (filter_to_do == PNG_FILTER_AVG) |
| 2430 | { |
| 2431 | png_bytep rp, dp, pp, lp; |
| 2432 | png_uint_32 i; |
| 2433 | for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, |
| 2434 | pp = prev_row + 1; i < bpp; i++) |
| 2435 | { |
| 2436 | *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); |
| 2437 | } |
| 2438 | for (lp = row_buf + 1; i < row_bytes; i++) |
| 2439 | { |
| 2440 | *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) |
| 2441 | & 0xff); |
| 2442 | } |
| 2443 | best_row = png_ptr->avg_row; |
| 2444 | } |
| 2445 | |
| 2446 | else if (filter_to_do & PNG_FILTER_AVG) |
| 2447 | { |
| 2448 | png_bytep rp, dp, pp, lp; |
| 2449 | png_uint_32 sum = 0, lmins = mins; |
| 2450 | png_uint_32 i; |
| 2451 | int v; |
| 2452 | |
| 2453 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2454 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
| 2455 | { |
| 2456 | int j; |
| 2457 | png_uint_32 lmhi, lmlo; |
| 2458 | lmlo = lmins & PNG_LOMASK; |
| 2459 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; |
| 2460 | |
| 2461 | for (j = 0; j < num_p_filters; j++) |
| 2462 | { |
| 2463 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG) |
| 2464 | { |
| 2465 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> |
| 2466 | PNG_WEIGHT_SHIFT; |
| 2467 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> |
| 2468 | PNG_WEIGHT_SHIFT; |
| 2469 | } |
| 2470 | } |
| 2471 | |
| 2472 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> |
| 2473 | PNG_COST_SHIFT; |
| 2474 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> |
| 2475 | PNG_COST_SHIFT; |
| 2476 | |
| 2477 | if (lmhi > PNG_HIMASK) |
| 2478 | lmins = PNG_MAXSUM; |
| 2479 | else |
| 2480 | lmins = (lmhi << PNG_HISHIFT) + lmlo; |
| 2481 | } |
| 2482 | #endif |
| 2483 | |
| 2484 | for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, |
| 2485 | pp = prev_row + 1; i < bpp; i++) |
| 2486 | { |
| 2487 | v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); |
| 2488 | |
| 2489 | sum += (v < 128) ? v : 256 - v; |
| 2490 | } |
| 2491 | for (lp = row_buf + 1; i < row_bytes; i++) |
| 2492 | { |
| 2493 | v = *dp++ = |
| 2494 | (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff); |
| 2495 | |
| 2496 | sum += (v < 128) ? v : 256 - v; |
| 2497 | |
| 2498 | if (sum > lmins) /* We are already worse, don't continue. */ |
| 2499 | break; |
| 2500 | } |
| 2501 | |
| 2502 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2503 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
| 2504 | { |
| 2505 | int j; |
| 2506 | png_uint_32 sumhi, sumlo; |
| 2507 | sumlo = sum & PNG_LOMASK; |
| 2508 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; |
| 2509 | |
| 2510 | for (j = 0; j < num_p_filters; j++) |
| 2511 | { |
| 2512 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) |
| 2513 | { |
| 2514 | sumlo = (sumlo * png_ptr->filter_weights[j]) >> |
| 2515 | PNG_WEIGHT_SHIFT; |
| 2516 | sumhi = (sumhi * png_ptr->filter_weights[j]) >> |
| 2517 | PNG_WEIGHT_SHIFT; |
| 2518 | } |
| 2519 | } |
| 2520 | |
| 2521 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> |
| 2522 | PNG_COST_SHIFT; |
| 2523 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> |
| 2524 | PNG_COST_SHIFT; |
| 2525 | |
| 2526 | if (sumhi > PNG_HIMASK) |
| 2527 | sum = PNG_MAXSUM; |
| 2528 | else |
| 2529 | sum = (sumhi << PNG_HISHIFT) + sumlo; |
| 2530 | } |
| 2531 | #endif |
| 2532 | |
| 2533 | if (sum < mins) |
| 2534 | { |
| 2535 | mins = sum; |
| 2536 | best_row = png_ptr->avg_row; |
| 2537 | } |
| 2538 | } |
| 2539 | |
| 2540 | /* Paeth filter */ |
| 2541 | if (filter_to_do == PNG_FILTER_PAETH) |
| 2542 | { |
| 2543 | png_bytep rp, dp, pp, cp, lp; |
| 2544 | png_uint_32 i; |
| 2545 | for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, |
| 2546 | pp = prev_row + 1; i < bpp; i++) |
| 2547 | { |
| 2548 | *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); |
| 2549 | } |
| 2550 | |
| 2551 | for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) |
| 2552 | { |
| 2553 | int a, b, c, pa, pb, pc, p; |
| 2554 | |
| 2555 | b = *pp++; |
| 2556 | c = *cp++; |
| 2557 | a = *lp++; |
| 2558 | |
| 2559 | p = b - c; |
| 2560 | pc = a - c; |
| 2561 | |
| 2562 | #ifdef PNG_USE_ABS |
| 2563 | pa = abs(p); |
| 2564 | pb = abs(pc); |
| 2565 | pc = abs(p + pc); |
| 2566 | #else |
| 2567 | pa = p < 0 ? -p : p; |
| 2568 | pb = pc < 0 ? -pc : pc; |
| 2569 | pc = (p + pc) < 0 ? -(p + pc) : p + pc; |
| 2570 | #endif |
| 2571 | |
| 2572 | p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; |
| 2573 | |
| 2574 | *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); |
| 2575 | } |
| 2576 | best_row = png_ptr->paeth_row; |
| 2577 | } |
| 2578 | |
| 2579 | else if (filter_to_do & PNG_FILTER_PAETH) |
| 2580 | { |
| 2581 | png_bytep rp, dp, pp, cp, lp; |
| 2582 | png_uint_32 sum = 0, lmins = mins; |
| 2583 | png_uint_32 i; |
| 2584 | int v; |
| 2585 | |
| 2586 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2587 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
| 2588 | { |
| 2589 | int j; |
| 2590 | png_uint_32 lmhi, lmlo; |
| 2591 | lmlo = lmins & PNG_LOMASK; |
| 2592 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; |
| 2593 | |
| 2594 | for (j = 0; j < num_p_filters; j++) |
| 2595 | { |
| 2596 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) |
| 2597 | { |
| 2598 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> |
| 2599 | PNG_WEIGHT_SHIFT; |
| 2600 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> |
| 2601 | PNG_WEIGHT_SHIFT; |
| 2602 | } |
| 2603 | } |
| 2604 | |
| 2605 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> |
| 2606 | PNG_COST_SHIFT; |
| 2607 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> |
| 2608 | PNG_COST_SHIFT; |
| 2609 | |
| 2610 | if (lmhi > PNG_HIMASK) |
| 2611 | lmins = PNG_MAXSUM; |
| 2612 | else |
| 2613 | lmins = (lmhi << PNG_HISHIFT) + lmlo; |
| 2614 | } |
| 2615 | #endif |
| 2616 | |
| 2617 | for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, |
| 2618 | pp = prev_row + 1; i < bpp; i++) |
| 2619 | { |
| 2620 | v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); |
| 2621 | |
| 2622 | sum += (v < 128) ? v : 256 - v; |
| 2623 | } |
| 2624 | |
| 2625 | for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) |
| 2626 | { |
| 2627 | int a, b, c, pa, pb, pc, p; |
| 2628 | |
| 2629 | b = *pp++; |
| 2630 | c = *cp++; |
| 2631 | a = *lp++; |
| 2632 | |
| 2633 | #ifndef PNG_SLOW_PAETH |
| 2634 | p = b - c; |
| 2635 | pc = a - c; |
| 2636 | #ifdef PNG_USE_ABS |
| 2637 | pa = abs(p); |
| 2638 | pb = abs(pc); |
| 2639 | pc = abs(p + pc); |
| 2640 | #else |
| 2641 | pa = p < 0 ? -p : p; |
| 2642 | pb = pc < 0 ? -pc : pc; |
| 2643 | pc = (p + pc) < 0 ? -(p + pc) : p + pc; |
| 2644 | #endif |
| 2645 | p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; |
| 2646 | #else /* PNG_SLOW_PAETH */ |
| 2647 | p = a + b - c; |
| 2648 | pa = abs(p - a); |
| 2649 | pb = abs(p - b); |
| 2650 | pc = abs(p - c); |
| 2651 | if (pa <= pb && pa <= pc) |
| 2652 | p = a; |
| 2653 | else if (pb <= pc) |
| 2654 | p = b; |
| 2655 | else |
| 2656 | p = c; |
| 2657 | #endif /* PNG_SLOW_PAETH */ |
| 2658 | |
| 2659 | v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); |
| 2660 | |
| 2661 | sum += (v < 128) ? v : 256 - v; |
| 2662 | |
| 2663 | if (sum > lmins) /* We are already worse, don't continue. */ |
| 2664 | break; |
| 2665 | } |
| 2666 | |
| 2667 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2668 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
| 2669 | { |
| 2670 | int j; |
| 2671 | png_uint_32 sumhi, sumlo; |
| 2672 | sumlo = sum & PNG_LOMASK; |
| 2673 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; |
| 2674 | |
| 2675 | for (j = 0; j < num_p_filters; j++) |
| 2676 | { |
| 2677 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) |
| 2678 | { |
| 2679 | sumlo = (sumlo * png_ptr->filter_weights[j]) >> |
| 2680 | PNG_WEIGHT_SHIFT; |
| 2681 | sumhi = (sumhi * png_ptr->filter_weights[j]) >> |
| 2682 | PNG_WEIGHT_SHIFT; |
| 2683 | } |
| 2684 | } |
| 2685 | |
| 2686 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> |
| 2687 | PNG_COST_SHIFT; |
| 2688 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> |
| 2689 | PNG_COST_SHIFT; |
| 2690 | |
| 2691 | if (sumhi > PNG_HIMASK) |
| 2692 | sum = PNG_MAXSUM; |
| 2693 | else |
| 2694 | sum = (sumhi << PNG_HISHIFT) + sumlo; |
| 2695 | } |
| 2696 | #endif |
| 2697 | |
| 2698 | if (sum < mins) |
| 2699 | { |
| 2700 | best_row = png_ptr->paeth_row; |
| 2701 | } |
| 2702 | } |
| 2703 | #endif /* PNG_WRITE_FILTER_SUPPORTED */ |
| 2704 | /* Do the actual writing of the filtered row data from the chosen filter. */ |
| 2705 | |
| 2706 | png_write_filtered_row(png_ptr, best_row); |
| 2707 | |
| 2708 | #ifdef PNG_WRITE_FILTER_SUPPORTED |
| 2709 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
| 2710 | /* Save the type of filter we picked this time for future calculations */ |
| 2711 | if (png_ptr->num_prev_filters > 0) |
| 2712 | { |
| 2713 | int j; |
| 2714 | for (j = 1; j < num_p_filters; j++) |
| 2715 | { |
| 2716 | png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1]; |
| 2717 | } |
| 2718 | png_ptr->prev_filters[j] = best_row[0]; |
| 2719 | } |
| 2720 | #endif |
| 2721 | #endif /* PNG_WRITE_FILTER_SUPPORTED */ |
| 2722 | } |
| 2723 | |
| 2724 | |
| 2725 | /* Do the actual writing of a previously filtered row. */ |
| 2726 | void /* PRIVATE */ |
| 2727 | png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) |
| 2728 | { |
| 2729 | png_debug(1, "in png_write_filtered_row"); |
| 2730 | |
| 2731 | png_debug1(2, "filter = %d", filtered_row[0]); |
| 2732 | /* Set up the zlib input buffer */ |
| 2733 | |
| 2734 | png_ptr->zstream.next_in = filtered_row; |
| 2735 | png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1; |
| 2736 | /* Repeat until we have compressed all the data */ |
| 2737 | do |
| 2738 | { |
| 2739 | int ret; /* Return of zlib */ |
| 2740 | |
| 2741 | /* Compress the data */ |
| 2742 | ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); |
| 2743 | /* Check for compression errors */ |
| 2744 | if (ret != Z_OK) |
| 2745 | { |
| 2746 | if (png_ptr->zstream.msg != NULL) |
| 2747 | png_error(png_ptr, png_ptr->zstream.msg); |
| 2748 | else |
| 2749 | png_error(png_ptr, "zlib error"); |
| 2750 | } |
| 2751 | |
| 2752 | /* See if it is time to write another IDAT */ |
| 2753 | if (!(png_ptr->zstream.avail_out)) |
| 2754 | { |
| 2755 | /* Write the IDAT and reset the zlib output buffer */ |
| 2756 | png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); |
| 2757 | png_ptr->zstream.next_out = png_ptr->zbuf; |
| 2758 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| 2759 | } |
| 2760 | /* Repeat until all data has been compressed */ |
| 2761 | } while (png_ptr->zstream.avail_in); |
| 2762 | |
| 2763 | /* Swap the current and previous rows */ |
| 2764 | if (png_ptr->prev_row != NULL) |
| 2765 | { |
| 2766 | png_bytep tptr; |
| 2767 | |
| 2768 | tptr = png_ptr->prev_row; |
| 2769 | png_ptr->prev_row = png_ptr->row_buf; |
| 2770 | png_ptr->row_buf = tptr; |
| 2771 | } |
| 2772 | |
| 2773 | /* Finish row - updates counters and flushes zlib if last row */ |
| 2774 | png_write_finish_row(png_ptr); |
| 2775 | |
| 2776 | #ifdef PNG_WRITE_FLUSH_SUPPORTED |
| 2777 | png_ptr->flush_rows++; |
| 2778 | |
| 2779 | if (png_ptr->flush_dist > 0 && |
| 2780 | png_ptr->flush_rows >= png_ptr->flush_dist) |
| 2781 | { |
| 2782 | png_write_flush(png_ptr); |
| 2783 | } |
| 2784 | #endif |
| 2785 | } |
| 2786 | #endif /* PNG_WRITE_SUPPORTED */ |