| 1 | ␍␊ |
| 2 | /* pngwutil.c - utilities to write a PNG file␍␊ |
| 3 | *␍␊ |
| 4 | * Last changed in libpng 1.5.10 [March 8, 2012]␍␊ |
| 5 | * Copyright (c) 1998-2012 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 | #include "pngpriv.h"␍␊ |
| 15 | ␍␊ |
| 16 | #ifdef PNG_WRITE_SUPPORTED␍␊ |
| 17 | ␍␊ |
| 18 | #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED␍␊ |
| 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. Note that,␍␊ |
| 36 | * the following works correctly even if png_int_32 has more than 32 bits␍␊ |
| 37 | * (compare the more complex code required on read for sign extention.)␍␊ |
| 38 | */␍␊ |
| 39 | void PNGAPI␍␊ |
| 40 | png_save_int_32(png_bytep buf, png_int_32 i)␍␊ |
| 41 | {␍␊ |
| 42 | buf[0] = (png_byte)((i >> 24) & 0xff);␍␊ |
| 43 | buf[1] = (png_byte)((i >> 16) & 0xff);␍␊ |
| 44 | buf[2] = (png_byte)((i >> 8) & 0xff);␍␊ |
| 45 | buf[3] = (png_byte)(i & 0xff);␍␊ |
| 46 | }␍␊ |
| 47 | #endif␍␊ |
| 48 | ␍␊ |
| 49 | /* Place a 16-bit number into a buffer in PNG byte order.␍␊ |
| 50 | * The parameter is declared unsigned int, not png_uint_16,␍␊ |
| 51 | * just to avoid potential problems on pre-ANSI C compilers.␍␊ |
| 52 | */␍␊ |
| 53 | void PNGAPI␍␊ |
| 54 | png_save_uint_16(png_bytep buf, unsigned int i)␍␊ |
| 55 | {␍␊ |
| 56 | buf[0] = (png_byte)((i >> 8) & 0xff);␍␊ |
| 57 | buf[1] = (png_byte)(i & 0xff);␍␊ |
| 58 | }␍␊ |
| 59 | #endif␍␊ |
| 60 | ␍␊ |
| 61 | /* Simple function to write the signature. If we have already written␍␊ |
| 62 | * the magic bytes of the signature, or more likely, the PNG stream is␍␊ |
| 63 | * being embedded into another stream and doesn't need its own signature,␍␊ |
| 64 | * we should call png_set_sig_bytes() to tell libpng how many of the␍␊ |
| 65 | * bytes have already been written.␍␊ |
| 66 | */␍␊ |
| 67 | void PNGAPI␍␊ |
| 68 | png_write_sig(png_structp png_ptr)␍␊ |
| 69 | {␍␊ |
| 70 | png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};␍␊ |
| 71 | ␍␊ |
| 72 | #ifdef PNG_IO_STATE_SUPPORTED␍␊ |
| 73 | /* Inform the I/O callback that the signature is being written */␍␊ |
| 74 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;␍␊ |
| 75 | #endif␍␊ |
| 76 | ␍␊ |
| 77 | /* Write the rest of the 8 byte signature */␍␊ |
| 78 | png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],␍␊ |
| 79 | (png_size_t)(8 - png_ptr->sig_bytes));␍␊ |
| 80 | ␍␊ |
| 81 | if (png_ptr->sig_bytes < 3)␍␊ |
| 82 | png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;␍␊ |
| 83 | }␍␊ |
| 84 | ␍␊ |
| 85 | /* Write the start of a PNG chunk. The type is the chunk type.␍␊ |
| 86 | * The total_length is the sum of the lengths of all the data you will be␍␊ |
| 87 | * passing in png_write_chunk_data().␍␊ |
| 88 | */␍␊ |
| 89 | static void␍␊ |
| 90 | png_write_chunk_header(png_structp png_ptr, png_uint_32 chunk_name,␍␊ |
| 91 | png_uint_32 length)␍␊ |
| 92 | {␍␊ |
| 93 | png_byte buf[8];␍␊ |
| 94 | ␍␊ |
| 95 | #if defined(PNG_DEBUG) && (PNG_DEBUG > 0)␍␊ |
| 96 | PNG_CSTRING_FROM_CHUNK(buf, chunk_name);␍␊ |
| 97 | png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);␍␊ |
| 98 | #endif␍␊ |
| 99 | ␍␊ |
| 100 | if (png_ptr == NULL)␍␊ |
| 101 | return;␍␊ |
| 102 | ␍␊ |
| 103 | #ifdef PNG_IO_STATE_SUPPORTED␍␊ |
| 104 | /* Inform the I/O callback that the chunk header is being written.␍␊ |
| 105 | * PNG_IO_CHUNK_HDR requires a single I/O call.␍␊ |
| 106 | */␍␊ |
| 107 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;␍␊ |
| 108 | #endif␍␊ |
| 109 | ␍␊ |
| 110 | /* Write the length and the chunk name */␍␊ |
| 111 | png_save_uint_32(buf, length);␍␊ |
| 112 | png_save_uint_32(buf + 4, chunk_name);␍␊ |
| 113 | png_write_data(png_ptr, buf, 8);␍␊ |
| 114 | ␍␊ |
| 115 | /* Put the chunk name into png_ptr->chunk_name */␍␊ |
| 116 | png_ptr->chunk_name = chunk_name;␍␊ |
| 117 | ␍␊ |
| 118 | /* Reset the crc and run it over the chunk name */␍␊ |
| 119 | png_reset_crc(png_ptr);␍␊ |
| 120 | ␍␊ |
| 121 | png_calculate_crc(png_ptr, buf + 4, 4);␍␊ |
| 122 | ␍␊ |
| 123 | #ifdef PNG_IO_STATE_SUPPORTED␍␊ |
| 124 | /* Inform the I/O callback that chunk data will (possibly) be written.␍␊ |
| 125 | * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.␍␊ |
| 126 | */␍␊ |
| 127 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;␍␊ |
| 128 | #endif␍␊ |
| 129 | }␍␊ |
| 130 | ␍␊ |
| 131 | void PNGAPI␍␊ |
| 132 | png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_string,␍␊ |
| 133 | png_uint_32 length)␍␊ |
| 134 | {␍␊ |
| 135 | png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);␍␊ |
| 136 | }␍␊ |
| 137 | ␍␊ |
| 138 | /* Write the data of a PNG chunk started with png_write_chunk_header().␍␊ |
| 139 | * Note that multiple calls to this function are allowed, and that the␍␊ |
| 140 | * sum of the lengths from these calls *must* add up to the total_length␍␊ |
| 141 | * given to png_write_chunk_header().␍␊ |
| 142 | */␍␊ |
| 143 | void PNGAPI␍␊ |
| 144 | png_write_chunk_data(png_structp png_ptr, png_const_bytep data,␍␊ |
| 145 | png_size_t length)␍␊ |
| 146 | {␍␊ |
| 147 | /* Write the data, and run the CRC over it */␍␊ |
| 148 | if (png_ptr == NULL)␍␊ |
| 149 | return;␍␊ |
| 150 | ␍␊ |
| 151 | if (data != NULL && length > 0)␍␊ |
| 152 | {␍␊ |
| 153 | png_write_data(png_ptr, data, length);␍␊ |
| 154 | ␍␊ |
| 155 | /* Update the CRC after writing the data,␍␊ |
| 156 | * in case that the user I/O routine alters it.␍␊ |
| 157 | */␍␊ |
| 158 | png_calculate_crc(png_ptr, data, length);␍␊ |
| 159 | }␍␊ |
| 160 | }␍␊ |
| 161 | ␍␊ |
| 162 | /* Finish a chunk started with png_write_chunk_header(). */␍␊ |
| 163 | void PNGAPI␍␊ |
| 164 | png_write_chunk_end(png_structp png_ptr)␍␊ |
| 165 | {␍␊ |
| 166 | png_byte buf[4];␍␊ |
| 167 | ␍␊ |
| 168 | if (png_ptr == NULL) return;␍␊ |
| 169 | ␍␊ |
| 170 | #ifdef PNG_IO_STATE_SUPPORTED␍␊ |
| 171 | /* Inform the I/O callback that the chunk CRC is being written.␍␊ |
| 172 | * PNG_IO_CHUNK_CRC requires a single I/O function call.␍␊ |
| 173 | */␍␊ |
| 174 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;␍␊ |
| 175 | #endif␍␊ |
| 176 | ␍␊ |
| 177 | /* Write the crc in a single operation */␍␊ |
| 178 | png_save_uint_32(buf, png_ptr->crc);␍␊ |
| 179 | ␍␊ |
| 180 | png_write_data(png_ptr, buf, (png_size_t)4);␍␊ |
| 181 | }␍␊ |
| 182 | ␍␊ |
| 183 | /* Write a PNG chunk all at once. The type is an array of ASCII characters␍␊ |
| 184 | * representing the chunk name. The array must be at least 4 bytes in␍␊ |
| 185 | * length, and does not need to be null terminated. To be safe, pass the␍␊ |
| 186 | * pre-defined chunk names here, and if you need a new one, define it␍␊ |
| 187 | * where the others are defined. The length is the length of the data.␍␊ |
| 188 | * All the data must be present. If that is not possible, use the␍␊ |
| 189 | * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()␍␊ |
| 190 | * functions instead.␍␊ |
| 191 | */␍␊ |
| 192 | static void␍␊ |
| 193 | png_write_complete_chunk(png_structp png_ptr, png_uint_32 chunk_name,␍␊ |
| 194 | png_const_bytep data, png_size_t length)␍␊ |
| 195 | {␍␊ |
| 196 | if (png_ptr == NULL)␍␊ |
| 197 | return;␍␊ |
| 198 | ␍␊ |
| 199 | /* On 64 bit architectures 'length' may not fit in a png_uint_32. */␍␊ |
| 200 | if (length > PNG_UINT_32_MAX)␍␊ |
| 201 | png_error(png_ptr, "length exceeds PNG maxima");␍␊ |
| 202 | ␍␊ |
| 203 | png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);␍␊ |
| 204 | png_write_chunk_data(png_ptr, data, length);␍␊ |
| 205 | png_write_chunk_end(png_ptr);␍␊ |
| 206 | }␍␊ |
| 207 | ␍␊ |
| 208 | /* This is the API that calls the internal function above. */␍␊ |
| 209 | void PNGAPI␍␊ |
| 210 | png_write_chunk(png_structp png_ptr, png_const_bytep chunk_string,␍␊ |
| 211 | png_const_bytep data, png_size_t length)␍␊ |
| 212 | {␍␊ |
| 213 | png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,␍␊ |
| 214 | length);␍␊ |
| 215 | }␍␊ |
| 216 | ␍␊ |
| 217 | /* Initialize the compressor for the appropriate type of compression. */␍␊ |
| 218 | static void␍␊ |
| 219 | png_zlib_claim(png_structp png_ptr, png_uint_32 state)␍␊ |
| 220 | {␍␊ |
| 221 | if (!(png_ptr->zlib_state & PNG_ZLIB_IN_USE))␍␊ |
| 222 | {␍␊ |
| 223 | /* If already initialized for 'state' do not re-init. */␍␊ |
| 224 | if (png_ptr->zlib_state != state)␍␊ |
| 225 | {␍␊ |
| 226 | int ret = Z_OK;␍␊ |
| 227 | png_const_charp who = "-";␍␊ |
| 228 | ␍␊ |
| 229 | /* If actually initialized for another state do a deflateEnd. */␍␊ |
| 230 | if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)␍␊ |
| 231 | {␍␊ |
| 232 | ret = deflateEnd(&png_ptr->zstream);␍␊ |
| 233 | who = "end";␍␊ |
| 234 | png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED;␍␊ |
| 235 | }␍␊ |
| 236 | ␍␊ |
| 237 | /* zlib itself detects an incomplete state on deflateEnd */␍␊ |
| 238 | if (ret == Z_OK) switch (state)␍␊ |
| 239 | {␍␊ |
| 240 | # ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED␍␊ |
| 241 | case PNG_ZLIB_FOR_TEXT:␍␊ |
| 242 | ret = deflateInit2(&png_ptr->zstream,␍␊ |
| 243 | png_ptr->zlib_text_level, png_ptr->zlib_text_method,␍␊ |
| 244 | png_ptr->zlib_text_window_bits,␍␊ |
| 245 | png_ptr->zlib_text_mem_level, png_ptr->zlib_text_strategy);␍␊ |
| 246 | who = "text";␍␊ |
| 247 | break;␍␊ |
| 248 | # endif␍␊ |
| 249 | ␍␊ |
| 250 | case PNG_ZLIB_FOR_IDAT:␍␊ |
| 251 | ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,␍␊ |
| 252 | png_ptr->zlib_method, png_ptr->zlib_window_bits,␍␊ |
| 253 | png_ptr->zlib_mem_level, png_ptr->zlib_strategy);␍␊ |
| 254 | who = "IDAT";␍␊ |
| 255 | break;␍␊ |
| 256 | ␍␊ |
| 257 | default:␍␊ |
| 258 | png_error(png_ptr, "invalid zlib state");␍␊ |
| 259 | }␍␊ |
| 260 | ␍␊ |
| 261 | if (ret == Z_OK)␍␊ |
| 262 | png_ptr->zlib_state = state;␍␊ |
| 263 | ␍␊ |
| 264 | else /* an error in deflateEnd or deflateInit2 */␍␊ |
| 265 | {␍␊ |
| 266 | size_t pos = 0;␍␊ |
| 267 | char msg[64];␍␊ |
| 268 | ␍␊ |
| 269 | pos = png_safecat(msg, sizeof msg, pos,␍␊ |
| 270 | "zlib failed to initialize compressor (");␍␊ |
| 271 | pos = png_safecat(msg, sizeof msg, pos, who);␍␊ |
| 272 | ␍␊ |
| 273 | switch (ret)␍␊ |
| 274 | {␍␊ |
| 275 | case Z_VERSION_ERROR:␍␊ |
| 276 | pos = png_safecat(msg, sizeof msg, pos, ") version error");␍␊ |
| 277 | break;␍␊ |
| 278 | ␍␊ |
| 279 | case Z_STREAM_ERROR:␍␊ |
| 280 | pos = png_safecat(msg, sizeof msg, pos, ") stream error");␍␊ |
| 281 | break;␍␊ |
| 282 | ␍␊ |
| 283 | case Z_MEM_ERROR:␍␊ |
| 284 | pos = png_safecat(msg, sizeof msg, pos, ") memory error");␍␊ |
| 285 | break;␍␊ |
| 286 | ␍␊ |
| 287 | default:␍␊ |
| 288 | pos = png_safecat(msg, sizeof msg, pos, ") unknown error");␍␊ |
| 289 | break;␍␊ |
| 290 | }␍␊ |
| 291 | ␍␊ |
| 292 | png_error(png_ptr, msg);␍␊ |
| 293 | }␍␊ |
| 294 | }␍␊ |
| 295 | ␍␊ |
| 296 | /* Here on success, claim the zstream: */␍␊ |
| 297 | png_ptr->zlib_state |= PNG_ZLIB_IN_USE;␍␊ |
| 298 | }␍␊ |
| 299 | ␍␊ |
| 300 | else␍␊ |
| 301 | png_error(png_ptr, "zstream already in use (internal error)");␍␊ |
| 302 | }␍␊ |
| 303 | ␍␊ |
| 304 | /* The opposite: release the stream. It is also reset, this API will warn on␍␊ |
| 305 | * error but will not fail.␍␊ |
| 306 | */␍␊ |
| 307 | static void␍␊ |
| 308 | png_zlib_release(png_structp png_ptr)␍␊ |
| 309 | {␍␊ |
| 310 | if (png_ptr->zlib_state & PNG_ZLIB_IN_USE)␍␊ |
| 311 | {␍␊ |
| 312 | int ret = deflateReset(&png_ptr->zstream);␍␊ |
| 313 | ␍␊ |
| 314 | png_ptr->zlib_state &= ~PNG_ZLIB_IN_USE;␍␊ |
| 315 | ␍␊ |
| 316 | if (ret != Z_OK)␍␊ |
| 317 | {␍␊ |
| 318 | png_const_charp err;␍␊ |
| 319 | PNG_WARNING_PARAMETERS(p)␍␊ |
| 320 | ␍␊ |
| 321 | switch (ret)␍␊ |
| 322 | {␍␊ |
| 323 | case Z_VERSION_ERROR:␍␊ |
| 324 | err = "version";␍␊ |
| 325 | break;␍␊ |
| 326 | ␍␊ |
| 327 | case Z_STREAM_ERROR:␍␊ |
| 328 | err = "stream";␍␊ |
| 329 | break;␍␊ |
| 330 | ␍␊ |
| 331 | case Z_MEM_ERROR:␍␊ |
| 332 | err = "memory";␍␊ |
| 333 | break;␍␊ |
| 334 | ␍␊ |
| 335 | default:␍␊ |
| 336 | err = "unknown";␍␊ |
| 337 | break;␍␊ |
| 338 | }␍␊ |
| 339 | ␍␊ |
| 340 | png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, ret);␍␊ |
| 341 | png_warning_parameter(p, 2, err);␍␊ |
| 342 | ␍␊ |
| 343 | if (png_ptr->zstream.msg)␍␊ |
| 344 | err = png_ptr->zstream.msg;␍␊ |
| 345 | else␍␊ |
| 346 | err = "[no zlib message]";␍␊ |
| 347 | ␍␊ |
| 348 | png_warning_parameter(p, 3, err);␍␊ |
| 349 | ␍␊ |
| 350 | png_formatted_warning(png_ptr, p,␍␊ |
| 351 | "zlib failed to reset compressor: @1(@2): @3");␍␊ |
| 352 | }␍␊ |
| 353 | }␍␊ |
| 354 | ␍␊ |
| 355 | else␍␊ |
| 356 | png_warning(png_ptr, "zstream not in use (internal error)");␍␊ |
| 357 | }␍␊ |
| 358 | ␍␊ |
| 359 | #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED␍␊ |
| 360 | /* This pair of functions encapsulates the operation of (a) compressing a␍␊ |
| 361 | * text string, and (b) issuing it later as a series of chunk data writes.␍␊ |
| 362 | * The compression_state structure is shared context for these functions␍␊ |
| 363 | * set up by the caller in order to make the whole mess thread-safe.␍␊ |
| 364 | */␍␊ |
| 365 | ␍␊ |
| 366 | typedef struct␍␊ |
| 367 | {␍␊ |
| 368 | png_const_bytep input; /* The uncompressed input data */␍␊ |
| 369 | png_size_t input_len; /* Its length */␍␊ |
| 370 | int num_output_ptr; /* Number of output pointers used */␍␊ |
| 371 | int max_output_ptr; /* Size of output_ptr */␍␊ |
| 372 | png_bytep *output_ptr; /* Array of pointers to output */␍␊ |
| 373 | } compression_state;␍␊ |
| 374 | ␍␊ |
| 375 | /* Compress given text into storage in the png_ptr structure */␍␊ |
| 376 | static int /* PRIVATE */␍␊ |
| 377 | png_text_compress(png_structp png_ptr,␍␊ |
| 378 | png_const_charp text, png_size_t text_len, int compression,␍␊ |
| 379 | compression_state *comp)␍␊ |
| 380 | {␍␊ |
| 381 | int ret;␍␊ |
| 382 | ␍␊ |
| 383 | comp->num_output_ptr = 0;␍␊ |
| 384 | comp->max_output_ptr = 0;␍␊ |
| 385 | comp->output_ptr = NULL;␍␊ |
| 386 | comp->input = NULL;␍␊ |
| 387 | comp->input_len = text_len;␍␊ |
| 388 | ␍␊ |
| 389 | /* We may just want to pass the text right through */␍␊ |
| 390 | if (compression == PNG_TEXT_COMPRESSION_NONE)␍␊ |
| 391 | {␍␊ |
| 392 | comp->input = (png_const_bytep)text;␍␊ |
| 393 | return((int)text_len);␍␊ |
| 394 | }␍␊ |
| 395 | ␍␊ |
| 396 | if (compression >= PNG_TEXT_COMPRESSION_LAST)␍␊ |
| 397 | {␍␊ |
| 398 | PNG_WARNING_PARAMETERS(p)␍␊ |
| 399 | ␍␊ |
| 400 | png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d,␍␊ |
| 401 | compression);␍␊ |
| 402 | png_formatted_warning(png_ptr, p, "Unknown compression type @1");␍␊ |
| 403 | }␍␊ |
| 404 | ␍␊ |
| 405 | /* We can't write the chunk until we find out how much data we have,␍␊ |
| 406 | * which means we need to run the compressor first and save the␍␊ |
| 407 | * output. This shouldn't be a problem, as the vast majority of␍␊ |
| 408 | * comments should be reasonable, but we will set up an array of␍␊ |
| 409 | * malloc'd pointers to be sure.␍␊ |
| 410 | *␍␊ |
| 411 | * If we knew the application was well behaved, we could simplify this␍␊ |
| 412 | * greatly by assuming we can always malloc an output buffer large␍␊ |
| 413 | * enough to hold the compressed text ((1001 * text_len / 1000) + 12)␍␊ |
| 414 | * and malloc this directly. The only time this would be a bad idea is␍␊ |
| 415 | * if we can't malloc more than 64K and we have 64K of random input␍␊ |
| 416 | * data, or if the input string is incredibly large (although this␍␊ |
| 417 | * wouldn't cause a failure, just a slowdown due to swapping).␍␊ |
| 418 | */␍␊ |
| 419 | png_zlib_claim(png_ptr, PNG_ZLIB_FOR_TEXT);␍␊ |
| 420 | ␍␊ |
| 421 | /* Set up the compression buffers */␍␊ |
| 422 | /* TODO: the following cast hides a potential overflow problem. */␍␊ |
| 423 | png_ptr->zstream.avail_in = (uInt)text_len;␍␊ |
| 424 | ␍␊ |
| 425 | /* NOTE: assume zlib doesn't overwrite the input */␍␊ |
| 426 | png_ptr->zstream.next_in = (Bytef *)text;␍␊ |
| 427 | png_ptr->zstream.avail_out = png_ptr->zbuf_size;␍␊ |
| 428 | png_ptr->zstream.next_out = png_ptr->zbuf;␍␊ |
| 429 | ␍␊ |
| 430 | /* This is the same compression loop as in png_write_row() */␍␊ |
| 431 | do␍␊ |
| 432 | {␍␊ |
| 433 | /* Compress the data */␍␊ |
| 434 | ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);␍␊ |
| 435 | ␍␊ |
| 436 | if (ret != Z_OK)␍␊ |
| 437 | {␍␊ |
| 438 | /* Error */␍␊ |
| 439 | if (png_ptr->zstream.msg != NULL)␍␊ |
| 440 | png_error(png_ptr, png_ptr->zstream.msg);␍␊ |
| 441 | ␍␊ |
| 442 | else␍␊ |
| 443 | png_error(png_ptr, "zlib error");␍␊ |
| 444 | }␍␊ |
| 445 | ␍␊ |
| 446 | /* Check to see if we need more room */␍␊ |
| 447 | if (!(png_ptr->zstream.avail_out))␍␊ |
| 448 | {␍␊ |
| 449 | /* Make sure the output array has room */␍␊ |
| 450 | if (comp->num_output_ptr >= comp->max_output_ptr)␍␊ |
| 451 | {␍␊ |
| 452 | int old_max;␍␊ |
| 453 | ␍␊ |
| 454 | old_max = comp->max_output_ptr;␍␊ |
| 455 | comp->max_output_ptr = comp->num_output_ptr + 4;␍␊ |
| 456 | if (comp->output_ptr != NULL)␍␊ |
| 457 | {␍␊ |
| 458 | png_bytepp old_ptr;␍␊ |
| 459 | ␍␊ |
| 460 | old_ptr = comp->output_ptr;␍␊ |
| 461 | ␍␊ |
| 462 | comp->output_ptr = (png_bytepp)png_malloc(png_ptr,␍␊ |
| 463 | (png_alloc_size_t)␍␊ |
| 464 | (comp->max_output_ptr * png_sizeof(png_charpp)));␍␊ |
| 465 | ␍␊ |
| 466 | png_memcpy(comp->output_ptr, old_ptr, old_max␍␊ |
| 467 | * png_sizeof(png_charp));␍␊ |
| 468 | ␍␊ |
| 469 | png_free(png_ptr, old_ptr);␍␊ |
| 470 | }␍␊ |
| 471 | else␍␊ |
| 472 | comp->output_ptr = (png_bytepp)png_malloc(png_ptr,␍␊ |
| 473 | (png_alloc_size_t)␍␊ |
| 474 | (comp->max_output_ptr * png_sizeof(png_charp)));␍␊ |
| 475 | }␍␊ |
| 476 | ␍␊ |
| 477 | /* Save the data */␍␊ |
| 478 | comp->output_ptr[comp->num_output_ptr] =␍␊ |
| 479 | (png_bytep)png_malloc(png_ptr,␍␊ |
| 480 | (png_alloc_size_t)png_ptr->zbuf_size);␍␊ |
| 481 | ␍␊ |
| 482 | png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,␍␊ |
| 483 | png_ptr->zbuf_size);␍␊ |
| 484 | ␍␊ |
| 485 | comp->num_output_ptr++;␍␊ |
| 486 | ␍␊ |
| 487 | /* and reset the buffer */␍␊ |
| 488 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;␍␊ |
| 489 | png_ptr->zstream.next_out = png_ptr->zbuf;␍␊ |
| 490 | }␍␊ |
| 491 | /* Continue until we don't have any more to compress */␍␊ |
| 492 | } while (png_ptr->zstream.avail_in);␍␊ |
| 493 | ␍␊ |
| 494 | /* Finish the compression */␍␊ |
| 495 | do␍␊ |
| 496 | {␍␊ |
| 497 | /* Tell zlib we are finished */␍␊ |
| 498 | ret = deflate(&png_ptr->zstream, Z_FINISH);␍␊ |
| 499 | ␍␊ |
| 500 | if (ret == Z_OK)␍␊ |
| 501 | {␍␊ |
| 502 | /* Check to see if we need more room */␍␊ |
| 503 | if (!(png_ptr->zstream.avail_out))␍␊ |
| 504 | {␍␊ |
| 505 | /* Check to make sure our output array has room */␍␊ |
| 506 | if (comp->num_output_ptr >= comp->max_output_ptr)␍␊ |
| 507 | {␍␊ |
| 508 | int old_max;␍␊ |
| 509 | ␍␊ |
| 510 | old_max = comp->max_output_ptr;␍␊ |
| 511 | comp->max_output_ptr = comp->num_output_ptr + 4;␍␊ |
| 512 | if (comp->output_ptr != NULL)␍␊ |
| 513 | {␍␊ |
| 514 | png_bytepp old_ptr;␍␊ |
| 515 | ␍␊ |
| 516 | old_ptr = comp->output_ptr;␍␊ |
| 517 | ␍␊ |
| 518 | /* This could be optimized to realloc() */␍␊ |
| 519 | comp->output_ptr = (png_bytepp)png_malloc(png_ptr,␍␊ |
| 520 | (png_alloc_size_t)(comp->max_output_ptr *␍␊ |
| 521 | png_sizeof(png_charp)));␍␊ |
| 522 | ␍␊ |
| 523 | png_memcpy(comp->output_ptr, old_ptr,␍␊ |
| 524 | old_max * png_sizeof(png_charp));␍␊ |
| 525 | ␍␊ |
| 526 | png_free(png_ptr, old_ptr);␍␊ |
| 527 | }␍␊ |
| 528 | ␍␊ |
| 529 | else␍␊ |
| 530 | comp->output_ptr = (png_bytepp)png_malloc(png_ptr,␍␊ |
| 531 | (png_alloc_size_t)(comp->max_output_ptr *␍␊ |
| 532 | png_sizeof(png_charp)));␍␊ |
| 533 | }␍␊ |
| 534 | ␍␊ |
| 535 | /* Save the data */␍␊ |
| 536 | comp->output_ptr[comp->num_output_ptr] =␍␊ |
| 537 | (png_bytep)png_malloc(png_ptr,␍␊ |
| 538 | (png_alloc_size_t)png_ptr->zbuf_size);␍␊ |
| 539 | ␍␊ |
| 540 | png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,␍␊ |
| 541 | png_ptr->zbuf_size);␍␊ |
| 542 | ␍␊ |
| 543 | comp->num_output_ptr++;␍␊ |
| 544 | ␍␊ |
| 545 | /* and reset the buffer pointers */␍␊ |
| 546 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;␍␊ |
| 547 | png_ptr->zstream.next_out = png_ptr->zbuf;␍␊ |
| 548 | }␍␊ |
| 549 | }␍␊ |
| 550 | else if (ret != Z_STREAM_END)␍␊ |
| 551 | {␍␊ |
| 552 | /* We got an error */␍␊ |
| 553 | if (png_ptr->zstream.msg != NULL)␍␊ |
| 554 | png_error(png_ptr, png_ptr->zstream.msg);␍␊ |
| 555 | ␍␊ |
| 556 | else␍␊ |
| 557 | png_error(png_ptr, "zlib error");␍␊ |
| 558 | }␍␊ |
| 559 | } while (ret != Z_STREAM_END);␍␊ |
| 560 | ␍␊ |
| 561 | /* Text length is number of buffers plus last buffer */␍␊ |
| 562 | text_len = png_ptr->zbuf_size * comp->num_output_ptr;␍␊ |
| 563 | ␍␊ |
| 564 | if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)␍␊ |
| 565 | text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;␍␊ |
| 566 | ␍␊ |
| 567 | return((int)text_len);␍␊ |
| 568 | }␍␊ |
| 569 | ␍␊ |
| 570 | /* Ship the compressed text out via chunk writes */␍␊ |
| 571 | static void /* PRIVATE */␍␊ |
| 572 | png_write_compressed_data_out(png_structp png_ptr, compression_state *comp,␍␊ |
| 573 | png_size_t data_len)␍␊ |
| 574 | {␍␊ |
| 575 | int i;␍␊ |
| 576 | ␍␊ |
| 577 | /* Handle the no-compression case */␍␊ |
| 578 | if (comp->input)␍␊ |
| 579 | {␍␊ |
| 580 | png_write_chunk_data(png_ptr, comp->input, data_len);␍␊ |
| 581 | ␍␊ |
| 582 | return;␍␊ |
| 583 | }␍␊ |
| 584 | ␍␊ |
| 585 | #ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED␍␊ |
| 586 | /* The zbuf_size test is because the code below doesn't work if zbuf_size is␍␊ |
| 587 | * '1'; simply skip it to avoid memory overwrite.␍␊ |
| 588 | */␍␊ |
| 589 | if (data_len >= 2 && comp->input_len < 16384 && png_ptr->zbuf_size > 1)␍␊ |
| 590 | {␍␊ |
| 591 | unsigned int z_cmf; /* zlib compression method and flags */␍␊ |
| 592 | ␍␊ |
| 593 | /* Optimize the CMF field in the zlib stream. This hack of the zlib␍␊ |
| 594 | * stream is compliant to the stream specification.␍␊ |
| 595 | */␍␊ |
| 596 | ␍␊ |
| 597 | if (comp->num_output_ptr)␍␊ |
| 598 | z_cmf = comp->output_ptr[0][0];␍␊ |
| 599 | else␍␊ |
| 600 | z_cmf = png_ptr->zbuf[0];␍␊ |
| 601 | ␍␊ |
| 602 | if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)␍␊ |
| 603 | {␍␊ |
| 604 | unsigned int z_cinfo;␍␊ |
| 605 | unsigned int half_z_window_size;␍␊ |
| 606 | png_size_t uncompressed_text_size = comp->input_len;␍␊ |
| 607 | ␍␊ |
| 608 | z_cinfo = z_cmf >> 4;␍␊ |
| 609 | half_z_window_size = 1 << (z_cinfo + 7);␍␊ |
| 610 | ␍␊ |
| 611 | while (uncompressed_text_size <= half_z_window_size &&␍␊ |
| 612 | half_z_window_size >= 256)␍␊ |
| 613 | {␍␊ |
| 614 | z_cinfo--;␍␊ |
| 615 | half_z_window_size >>= 1;␍␊ |
| 616 | }␍␊ |
| 617 | ␍␊ |
| 618 | z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);␍␊ |
| 619 | ␍␊ |
| 620 | if (comp->num_output_ptr)␍␊ |
| 621 | {␍␊ |
| 622 | ␍␊ |
| 623 | if (comp->output_ptr[0][0] != z_cmf)␍␊ |
| 624 | {␍␊ |
| 625 | int tmp;␍␊ |
| 626 | ␍␊ |
| 627 | comp->output_ptr[0][0] = (png_byte)z_cmf;␍␊ |
| 628 | tmp = comp->output_ptr[0][1] & 0xe0;␍␊ |
| 629 | tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;␍␊ |
| 630 | comp->output_ptr[0][1] = (png_byte)tmp;␍␊ |
| 631 | }␍␊ |
| 632 | }␍␊ |
| 633 | else␍␊ |
| 634 | {␍␊ |
| 635 | int tmp;␍␊ |
| 636 | ␍␊ |
| 637 | png_ptr->zbuf[0] = (png_byte)z_cmf;␍␊ |
| 638 | tmp = png_ptr->zbuf[1] & 0xe0;␍␊ |
| 639 | tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;␍␊ |
| 640 | png_ptr->zbuf[1] = (png_byte)tmp;␍␊ |
| 641 | }␍␊ |
| 642 | }␍␊ |
| 643 | ␍␊ |
| 644 | else␍␊ |
| 645 | png_error(png_ptr,␍␊ |
| 646 | "Invalid zlib compression method or flags in non-IDAT chunk");␍␊ |
| 647 | }␍␊ |
| 648 | #endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */␍␊ |
| 649 | ␍␊ |
| 650 | /* Write saved output buffers, if any */␍␊ |
| 651 | for (i = 0; i < comp->num_output_ptr; i++)␍␊ |
| 652 | {␍␊ |
| 653 | png_write_chunk_data(png_ptr, comp->output_ptr[i],␍␊ |
| 654 | (png_size_t)png_ptr->zbuf_size);␍␊ |
| 655 | ␍␊ |
| 656 | png_free(png_ptr, comp->output_ptr[i]);␍␊ |
| 657 | }␍␊ |
| 658 | ␍␊ |
| 659 | if (comp->max_output_ptr != 0)␍␊ |
| 660 | png_free(png_ptr, comp->output_ptr);␍␊ |
| 661 | ␍␊ |
| 662 | /* Write anything left in zbuf */␍␊ |
| 663 | if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)␍␊ |
| 664 | png_write_chunk_data(png_ptr, png_ptr->zbuf,␍␊ |
| 665 | (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));␍␊ |
| 666 | ␍␊ |
| 667 | /* Reset zlib for another zTXt/iTXt or image data */␍␊ |
| 668 | png_zlib_release(png_ptr);␍␊ |
| 669 | }␍␊ |
| 670 | #endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */␍␊ |
| 671 | ␍␊ |
| 672 | /* Write the IHDR chunk, and update the png_struct with the necessary␍␊ |
| 673 | * information. Note that the rest of this code depends upon this␍␊ |
| 674 | * information being correct.␍␊ |
| 675 | */␍␊ |
| 676 | void /* PRIVATE */␍␊ |
| 677 | png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,␍␊ |
| 678 | int bit_depth, int color_type, int compression_type, int filter_type,␍␊ |
| 679 | int interlace_type)␍␊ |
| 680 | {␍␊ |
| 681 | png_byte buf[13]; /* Buffer to store the IHDR info */␍␊ |
| 682 | ␍␊ |
| 683 | png_debug(1, "in png_write_IHDR");␍␊ |
| 684 | ␍␊ |
| 685 | /* Check that we have valid input data from the application info */␍␊ |
| 686 | switch (color_type)␍␊ |
| 687 | {␍␊ |
| 688 | case PNG_COLOR_TYPE_GRAY:␍␊ |
| 689 | switch (bit_depth)␍␊ |
| 690 | {␍␊ |
| 691 | case 1:␍␊ |
| 692 | case 2:␍␊ |
| 693 | case 4:␍␊ |
| 694 | case 8:␍␊ |
| 695 | #ifdef PNG_WRITE_16BIT_SUPPORTED␍␊ |
| 696 | case 16:␍␊ |
| 697 | #endif␍␊ |
| 698 | png_ptr->channels = 1; break;␍␊ |
| 699 | ␍␊ |
| 700 | default:␍␊ |
| 701 | png_error(png_ptr,␍␊ |
| 702 | "Invalid bit depth for grayscale image");␍␊ |
| 703 | }␍␊ |
| 704 | break;␍␊ |
| 705 | ␍␊ |
| 706 | case PNG_COLOR_TYPE_RGB:␍␊ |
| 707 | #ifdef PNG_WRITE_16BIT_SUPPORTED␍␊ |
| 708 | if (bit_depth != 8 && bit_depth != 16)␍␊ |
| 709 | #else␍␊ |
| 710 | if (bit_depth != 8)␍␊ |
| 711 | #endif␍␊ |
| 712 | png_error(png_ptr, "Invalid bit depth for RGB image");␍␊ |
| 713 | ␍␊ |
| 714 | png_ptr->channels = 3;␍␊ |
| 715 | break;␍␊ |
| 716 | ␍␊ |
| 717 | case PNG_COLOR_TYPE_PALETTE:␍␊ |
| 718 | switch (bit_depth)␍␊ |
| 719 | {␍␊ |
| 720 | case 1:␍␊ |
| 721 | case 2:␍␊ |
| 722 | case 4:␍␊ |
| 723 | case 8:␍␊ |
| 724 | png_ptr->channels = 1;␍␊ |
| 725 | break;␍␊ |
| 726 | ␍␊ |
| 727 | default:␍␊ |
| 728 | png_error(png_ptr, "Invalid bit depth for paletted image");␍␊ |
| 729 | }␍␊ |
| 730 | break;␍␊ |
| 731 | ␍␊ |
| 732 | case PNG_COLOR_TYPE_GRAY_ALPHA:␍␊ |
| 733 | if (bit_depth != 8 && bit_depth != 16)␍␊ |
| 734 | png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");␍␊ |
| 735 | ␍␊ |
| 736 | png_ptr->channels = 2;␍␊ |
| 737 | break;␍␊ |
| 738 | ␍␊ |
| 739 | case PNG_COLOR_TYPE_RGB_ALPHA:␍␊ |
| 740 | #ifdef PNG_WRITE_16BIT_SUPPORTED␍␊ |
| 741 | if (bit_depth != 8 && bit_depth != 16)␍␊ |
| 742 | #else␍␊ |
| 743 | if (bit_depth != 8)␍␊ |
| 744 | #endif␍␊ |
| 745 | png_error(png_ptr, "Invalid bit depth for RGBA image");␍␊ |
| 746 | ␍␊ |
| 747 | png_ptr->channels = 4;␍␊ |
| 748 | break;␍␊ |
| 749 | ␍␊ |
| 750 | default:␍␊ |
| 751 | png_error(png_ptr, "Invalid image color type specified");␍␊ |
| 752 | }␍␊ |
| 753 | ␍␊ |
| 754 | if (compression_type != PNG_COMPRESSION_TYPE_BASE)␍␊ |
| 755 | {␍␊ |
| 756 | png_warning(png_ptr, "Invalid compression type specified");␍␊ |
| 757 | compression_type = PNG_COMPRESSION_TYPE_BASE;␍␊ |
| 758 | }␍␊ |
| 759 | ␍␊ |
| 760 | /* Write filter_method 64 (intrapixel differencing) only if␍␊ |
| 761 | * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and␍␊ |
| 762 | * 2. Libpng did not write a PNG signature (this filter_method is only␍␊ |
| 763 | * used in PNG datastreams that are embedded in MNG datastreams) and␍␊ |
| 764 | * 3. The application called png_permit_mng_features with a mask that␍␊ |
| 765 | * included PNG_FLAG_MNG_FILTER_64 and␍␊ |
| 766 | * 4. The filter_method is 64 and␍␊ |
| 767 | * 5. The color_type is RGB or RGBA␍␊ |
| 768 | */␍␊ |
| 769 | if (␍␊ |
| 770 | #ifdef PNG_MNG_FEATURES_SUPPORTED␍␊ |
| 771 | !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&␍␊ |
| 772 | ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&␍␊ |
| 773 | (color_type == PNG_COLOR_TYPE_RGB ||␍␊ |
| 774 | color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&␍␊ |
| 775 | (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&␍␊ |
| 776 | #endif␍␊ |
| 777 | filter_type != PNG_FILTER_TYPE_BASE)␍␊ |
| 778 | {␍␊ |
| 779 | png_warning(png_ptr, "Invalid filter type specified");␍␊ |
| 780 | filter_type = PNG_FILTER_TYPE_BASE;␍␊ |
| 781 | }␍␊ |
| 782 | ␍␊ |
| 783 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED␍␊ |
| 784 | if (interlace_type != PNG_INTERLACE_NONE &&␍␊ |
| 785 | interlace_type != PNG_INTERLACE_ADAM7)␍␊ |
| 786 | {␍␊ |
| 787 | png_warning(png_ptr, "Invalid interlace type specified");␍␊ |
| 788 | interlace_type = PNG_INTERLACE_ADAM7;␍␊ |
| 789 | }␍␊ |
| 790 | #else␍␊ |
| 791 | interlace_type=PNG_INTERLACE_NONE;␍␊ |
| 792 | #endif␍␊ |
| 793 | ␍␊ |
| 794 | /* Save the relevent information */␍␊ |
| 795 | png_ptr->bit_depth = (png_byte)bit_depth;␍␊ |
| 796 | png_ptr->color_type = (png_byte)color_type;␍␊ |
| 797 | png_ptr->interlaced = (png_byte)interlace_type;␍␊ |
| 798 | #ifdef PNG_MNG_FEATURES_SUPPORTED␍␊ |
| 799 | png_ptr->filter_type = (png_byte)filter_type;␍␊ |
| 800 | #endif␍␊ |
| 801 | png_ptr->compression_type = (png_byte)compression_type;␍␊ |
| 802 | png_ptr->width = width;␍␊ |
| 803 | png_ptr->height = height;␍␊ |
| 804 | ␍␊ |
| 805 | png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);␍␊ |
| 806 | png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);␍␊ |
| 807 | /* Set the usr info, so any transformations can modify it */␍␊ |
| 808 | png_ptr->usr_width = png_ptr->width;␍␊ |
| 809 | png_ptr->usr_bit_depth = png_ptr->bit_depth;␍␊ |
| 810 | png_ptr->usr_channels = png_ptr->channels;␍␊ |
| 811 | ␍␊ |
| 812 | /* Pack the header information into the buffer */␍␊ |
| 813 | png_save_uint_32(buf, width);␍␊ |
| 814 | png_save_uint_32(buf + 4, height);␍␊ |
| 815 | buf[8] = (png_byte)bit_depth;␍␊ |
| 816 | buf[9] = (png_byte)color_type;␍␊ |
| 817 | buf[10] = (png_byte)compression_type;␍␊ |
| 818 | buf[11] = (png_byte)filter_type;␍␊ |
| 819 | buf[12] = (png_byte)interlace_type;␍␊ |
| 820 | ␍␊ |
| 821 | /* Write the chunk */␍␊ |
| 822 | png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);␍␊ |
| 823 | ␍␊ |
| 824 | /* Initialize zlib with PNG info */␍␊ |
| 825 | png_ptr->zstream.zalloc = png_zalloc;␍␊ |
| 826 | png_ptr->zstream.zfree = png_zfree;␍␊ |
| 827 | png_ptr->zstream.opaque = (voidpf)png_ptr;␍␊ |
| 828 | ␍␊ |
| 829 | if (!(png_ptr->do_filter))␍␊ |
| 830 | {␍␊ |
| 831 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||␍␊ |
| 832 | png_ptr->bit_depth < 8)␍␊ |
| 833 | png_ptr->do_filter = PNG_FILTER_NONE;␍␊ |
| 834 | ␍␊ |
| 835 | else␍␊ |
| 836 | png_ptr->do_filter = PNG_ALL_FILTERS;␍␊ |
| 837 | }␍␊ |
| 838 | ␍␊ |
| 839 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))␍␊ |
| 840 | {␍␊ |
| 841 | if (png_ptr->do_filter != PNG_FILTER_NONE)␍␊ |
| 842 | png_ptr->zlib_strategy = Z_FILTERED;␍␊ |
| 843 | ␍␊ |
| 844 | else␍␊ |
| 845 | png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;␍␊ |
| 846 | }␍␊ |
| 847 | ␍␊ |
| 848 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))␍␊ |
| 849 | png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;␍␊ |
| 850 | ␍␊ |
| 851 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))␍␊ |
| 852 | png_ptr->zlib_mem_level = 8;␍␊ |
| 853 | ␍␊ |
| 854 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))␍␊ |
| 855 | png_ptr->zlib_window_bits = 15;␍␊ |
| 856 | ␍␊ |
| 857 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))␍␊ |
| 858 | png_ptr->zlib_method = 8;␍␊ |
| 859 | ␍␊ |
| 860 | #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED␍␊ |
| 861 | #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED␍␊ |
| 862 | if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_STRATEGY))␍␊ |
| 863 | png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY;␍␊ |
| 864 | ␍␊ |
| 865 | if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_LEVEL))␍␊ |
| 866 | png_ptr->zlib_text_level = png_ptr->zlib_level;␍␊ |
| 867 | ␍␊ |
| 868 | if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL))␍␊ |
| 869 | png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level;␍␊ |
| 870 | ␍␊ |
| 871 | if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS))␍␊ |
| 872 | png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits;␍␊ |
| 873 | ␍␊ |
| 874 | if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_METHOD))␍␊ |
| 875 | png_ptr->zlib_text_method = png_ptr->zlib_method;␍␊ |
| 876 | #else␍␊ |
| 877 | png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY;␍␊ |
| 878 | png_ptr->zlib_text_level = png_ptr->zlib_level;␍␊ |
| 879 | png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level;␍␊ |
| 880 | png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits;␍␊ |
| 881 | png_ptr->zlib_text_method = png_ptr->zlib_method;␍␊ |
| 882 | #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */␍␊ |
| 883 | #endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */␍␊ |
| 884 | ␍␊ |
| 885 | /* Record that the compressor has not yet been initialized. */␍␊ |
| 886 | png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED;␍␊ |
| 887 | ␍␊ |
| 888 | png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */␍␊ |
| 889 | }␍␊ |
| 890 | ␍␊ |
| 891 | /* Write the palette. We are careful not to trust png_color to be in the␍␊ |
| 892 | * correct order for PNG, so people can redefine it to any convenient␍␊ |
| 893 | * structure.␍␊ |
| 894 | */␍␊ |
| 895 | void /* PRIVATE */␍␊ |
| 896 | png_write_PLTE(png_structp png_ptr, png_const_colorp palette,␍␊ |
| 897 | png_uint_32 num_pal)␍␊ |
| 898 | {␍␊ |
| 899 | png_uint_32 i;␍␊ |
| 900 | png_const_colorp pal_ptr;␍␊ |
| 901 | png_byte buf[3];␍␊ |
| 902 | ␍␊ |
| 903 | png_debug(1, "in png_write_PLTE");␍␊ |
| 904 | ␍␊ |
| 905 | if ((␍␊ |
| 906 | #ifdef PNG_MNG_FEATURES_SUPPORTED␍␊ |
| 907 | !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&␍␊ |
| 908 | #endif␍␊ |
| 909 | num_pal == 0) || num_pal > 256)␍␊ |
| 910 | {␍␊ |
| 911 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)␍␊ |
| 912 | {␍␊ |
| 913 | png_error(png_ptr, "Invalid number of colors in palette");␍␊ |
| 914 | }␍␊ |
| 915 | ␍␊ |
| 916 | else␍␊ |
| 917 | {␍␊ |
| 918 | png_warning(png_ptr, "Invalid number of colors in palette");␍␊ |
| 919 | return;␍␊ |
| 920 | }␍␊ |
| 921 | }␍␊ |
| 922 | ␍␊ |
| 923 | if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))␍␊ |
| 924 | {␍␊ |
| 925 | png_warning(png_ptr,␍␊ |
| 926 | "Ignoring request to write a PLTE chunk in grayscale PNG");␍␊ |
| 927 | ␍␊ |
| 928 | return;␍␊ |
| 929 | }␍␊ |
| 930 | ␍␊ |
| 931 | png_ptr->num_palette = (png_uint_16)num_pal;␍␊ |
| 932 | png_debug1(3, "num_palette = %d", png_ptr->num_palette);␍␊ |
| 933 | ␍␊ |
| 934 | png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));␍␊ |
| 935 | #ifdef PNG_POINTER_INDEXING_SUPPORTED␍␊ |
| 936 | ␍␊ |
| 937 | for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)␍␊ |
| 938 | {␍␊ |
| 939 | buf[0] = pal_ptr->red;␍␊ |
| 940 | buf[1] = pal_ptr->green;␍␊ |
| 941 | buf[2] = pal_ptr->blue;␍␊ |
| 942 | png_write_chunk_data(png_ptr, buf, (png_size_t)3);␍␊ |
| 943 | }␍␊ |
| 944 | ␍␊ |
| 945 | #else␍␊ |
| 946 | /* This is a little slower but some buggy compilers need to do this␍␊ |
| 947 | * instead␍␊ |
| 948 | */␍␊ |
| 949 | pal_ptr=palette;␍␊ |
| 950 | ␍␊ |
| 951 | for (i = 0; i < num_pal; i++)␍␊ |
| 952 | {␍␊ |
| 953 | buf[0] = pal_ptr[i].red;␍␊ |
| 954 | buf[1] = pal_ptr[i].green;␍␊ |
| 955 | buf[2] = pal_ptr[i].blue;␍␊ |
| 956 | png_write_chunk_data(png_ptr, buf, (png_size_t)3);␍␊ |
| 957 | }␍␊ |
| 958 | ␍␊ |
| 959 | #endif␍␊ |
| 960 | png_write_chunk_end(png_ptr);␍␊ |
| 961 | png_ptr->mode |= PNG_HAVE_PLTE;␍␊ |
| 962 | }␍␊ |
| 963 | ␍␊ |
| 964 | /* Write an IDAT chunk */␍␊ |
| 965 | void /* PRIVATE */␍␊ |
| 966 | png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)␍␊ |
| 967 | {␍␊ |
| 968 | png_debug(1, "in png_write_IDAT");␍␊ |
| 969 | ␍␊ |
| 970 | #ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED␍␊ |
| 971 | if (!(png_ptr->mode & PNG_HAVE_IDAT) &&␍␊ |
| 972 | png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)␍␊ |
| 973 | {␍␊ |
| 974 | /* Optimize the CMF field in the zlib stream. This hack of the zlib␍␊ |
| 975 | * stream is compliant to the stream specification.␍␊ |
| 976 | */␍␊ |
| 977 | unsigned int z_cmf = data[0]; /* zlib compression method and flags */␍␊ |
| 978 | ␍␊ |
| 979 | if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)␍␊ |
| 980 | {␍␊ |
| 981 | /* Avoid memory underflows and multiplication overflows.␍␊ |
| 982 | *␍␊ |
| 983 | * The conditions below are practically always satisfied;␍␊ |
| 984 | * however, they still must be checked.␍␊ |
| 985 | */␍␊ |
| 986 | if (length >= 2 &&␍␊ |
| 987 | png_ptr->height < 16384 && png_ptr->width < 16384)␍␊ |
| 988 | {␍␊ |
| 989 | /* Compute the maximum possible length of the datastream */␍␊ |
| 990 | ␍␊ |
| 991 | /* Number of pixels, plus for each row a filter byte␍␊ |
| 992 | * and possibly a padding byte, so increase the maximum␍␊ |
| 993 | * size to account for these.␍␊ |
| 994 | */␍␊ |
| 995 | unsigned int z_cinfo;␍␊ |
| 996 | unsigned int half_z_window_size;␍␊ |
| 997 | png_uint_32 uncompressed_idat_size = png_ptr->height *␍␊ |
| 998 | ((png_ptr->width *␍␊ |
| 999 | png_ptr->channels * png_ptr->bit_depth + 15) >> 3);␍␊ |
| 1000 | ␍␊ |
| 1001 | /* If it's interlaced, each block of 8 rows is sent as up to␍␊ |
| 1002 | * 14 rows, i.e., 6 additional rows, each with a filter byte␍␊ |
| 1003 | * and possibly a padding byte␍␊ |
| 1004 | */␍␊ |
| 1005 | if (png_ptr->interlaced)␍␊ |
| 1006 | uncompressed_idat_size += ((png_ptr->height + 7)/8) *␍␊ |
| 1007 | (png_ptr->bit_depth < 8 ? 12 : 6);␍␊ |
| 1008 | ␍␊ |
| 1009 | z_cinfo = z_cmf >> 4;␍␊ |
| 1010 | half_z_window_size = 1 << (z_cinfo + 7);␍␊ |
| 1011 | ␍␊ |
| 1012 | while (uncompressed_idat_size <= half_z_window_size &&␍␊ |
| 1013 | half_z_window_size >= 256)␍␊ |
| 1014 | {␍␊ |
| 1015 | z_cinfo--;␍␊ |
| 1016 | half_z_window_size >>= 1;␍␊ |
| 1017 | }␍␊ |
| 1018 | ␍␊ |
| 1019 | z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);␍␊ |
| 1020 | ␍␊ |
| 1021 | if (data[0] != z_cmf)␍␊ |
| 1022 | {␍␊ |
| 1023 | int tmp;␍␊ |
| 1024 | data[0] = (png_byte)z_cmf;␍␊ |
| 1025 | tmp = data[1] & 0xe0;␍␊ |
| 1026 | tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;␍␊ |
| 1027 | data[1] = (png_byte)tmp;␍␊ |
| 1028 | }␍␊ |
| 1029 | }␍␊ |
| 1030 | }␍␊ |
| 1031 | ␍␊ |
| 1032 | else␍␊ |
| 1033 | png_error(png_ptr,␍␊ |
| 1034 | "Invalid zlib compression method or flags in IDAT");␍␊ |
| 1035 | }␍␊ |
| 1036 | #endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */␍␊ |
| 1037 | ␍␊ |
| 1038 | png_write_complete_chunk(png_ptr, png_IDAT, data, length);␍␊ |
| 1039 | png_ptr->mode |= PNG_HAVE_IDAT;␍␊ |
| 1040 | ␍␊ |
| 1041 | /* Prior to 1.5.4 this code was replicated in every caller (except at the␍␊ |
| 1042 | * end, where it isn't technically necessary). Since this function has␍␊ |
| 1043 | * flushed the data we can safely reset the zlib output buffer here.␍␊ |
| 1044 | */␍␊ |
| 1045 | png_ptr->zstream.next_out = png_ptr->zbuf;␍␊ |
| 1046 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;␍␊ |
| 1047 | }␍␊ |
| 1048 | ␍␊ |
| 1049 | /* Write an IEND chunk */␍␊ |
| 1050 | void /* PRIVATE */␍␊ |
| 1051 | png_write_IEND(png_structp png_ptr)␍␊ |
| 1052 | {␍␊ |
| 1053 | png_debug(1, "in png_write_IEND");␍␊ |
| 1054 | ␍␊ |
| 1055 | png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0);␍␊ |
| 1056 | png_ptr->mode |= PNG_HAVE_IEND;␍␊ |
| 1057 | }␍␊ |
| 1058 | ␍␊ |
| 1059 | #ifdef PNG_WRITE_gAMA_SUPPORTED␍␊ |
| 1060 | /* Write a gAMA chunk */␍␊ |
| 1061 | void /* PRIVATE */␍␊ |
| 1062 | png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)␍␊ |
| 1063 | {␍␊ |
| 1064 | png_byte buf[4];␍␊ |
| 1065 | ␍␊ |
| 1066 | png_debug(1, "in png_write_gAMA");␍␊ |
| 1067 | ␍␊ |
| 1068 | /* file_gamma is saved in 1/100,000ths */␍␊ |
| 1069 | png_save_uint_32(buf, (png_uint_32)file_gamma);␍␊ |
| 1070 | png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);␍␊ |
| 1071 | }␍␊ |
| 1072 | #endif␍␊ |
| 1073 | ␍␊ |
| 1074 | #ifdef PNG_WRITE_sRGB_SUPPORTED␍␊ |
| 1075 | /* Write a sRGB chunk */␍␊ |
| 1076 | void /* PRIVATE */␍␊ |
| 1077 | png_write_sRGB(png_structp png_ptr, int srgb_intent)␍␊ |
| 1078 | {␍␊ |
| 1079 | png_byte buf[1];␍␊ |
| 1080 | ␍␊ |
| 1081 | png_debug(1, "in png_write_sRGB");␍␊ |
| 1082 | ␍␊ |
| 1083 | if (srgb_intent >= PNG_sRGB_INTENT_LAST)␍␊ |
| 1084 | png_warning(png_ptr,␍␊ |
| 1085 | "Invalid sRGB rendering intent specified");␍␊ |
| 1086 | ␍␊ |
| 1087 | buf[0]=(png_byte)srgb_intent;␍␊ |
| 1088 | png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);␍␊ |
| 1089 | }␍␊ |
| 1090 | #endif␍␊ |
| 1091 | ␍␊ |
| 1092 | #ifdef PNG_WRITE_iCCP_SUPPORTED␍␊ |
| 1093 | /* Write an iCCP chunk */␍␊ |
| 1094 | void /* PRIVATE */␍␊ |
| 1095 | png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type,␍␊ |
| 1096 | png_const_charp profile, int profile_len)␍␊ |
| 1097 | {␍␊ |
| 1098 | png_size_t name_len;␍␊ |
| 1099 | png_charp new_name;␍␊ |
| 1100 | compression_state comp;␍␊ |
| 1101 | int embedded_profile_len = 0;␍␊ |
| 1102 | ␍␊ |
| 1103 | png_debug(1, "in png_write_iCCP");␍␊ |
| 1104 | ␍␊ |
| 1105 | comp.num_output_ptr = 0;␍␊ |
| 1106 | comp.max_output_ptr = 0;␍␊ |
| 1107 | comp.output_ptr = NULL;␍␊ |
| 1108 | comp.input = NULL;␍␊ |
| 1109 | comp.input_len = 0;␍␊ |
| 1110 | ␍␊ |
| 1111 | if ((name_len = png_check_keyword(png_ptr, name, &new_name)) == 0)␍␊ |
| 1112 | return;␍␊ |
| 1113 | ␍␊ |
| 1114 | if (compression_type != PNG_COMPRESSION_TYPE_BASE)␍␊ |
| 1115 | png_warning(png_ptr, "Unknown compression type in iCCP chunk");␍␊ |
| 1116 | ␍␊ |
| 1117 | if (profile == NULL)␍␊ |
| 1118 | profile_len = 0;␍␊ |
| 1119 | ␍␊ |
| 1120 | if (profile_len > 3)␍␊ |
| 1121 | embedded_profile_len =␍␊ |
| 1122 | ((*( (png_const_bytep)profile ))<<24) |␍␊ |
| 1123 | ((*( (png_const_bytep)profile + 1))<<16) |␍␊ |
| 1124 | ((*( (png_const_bytep)profile + 2))<< 8) |␍␊ |
| 1125 | ((*( (png_const_bytep)profile + 3)) );␍␊ |
| 1126 | ␍␊ |
| 1127 | if (embedded_profile_len < 0)␍␊ |
| 1128 | {␍␊ |
| 1129 | png_warning(png_ptr,␍␊ |
| 1130 | "Embedded profile length in iCCP chunk is negative");␍␊ |
| 1131 | ␍␊ |
| 1132 | png_free(png_ptr, new_name);␍␊ |
| 1133 | return;␍␊ |
| 1134 | }␍␊ |
| 1135 | ␍␊ |
| 1136 | if (profile_len < embedded_profile_len)␍␊ |
| 1137 | {␍␊ |
| 1138 | png_warning(png_ptr,␍␊ |
| 1139 | "Embedded profile length too large in iCCP chunk");␍␊ |
| 1140 | ␍␊ |
| 1141 | png_free(png_ptr, new_name);␍␊ |
| 1142 | return;␍␊ |
| 1143 | }␍␊ |
| 1144 | ␍␊ |
| 1145 | if (profile_len > embedded_profile_len)␍␊ |
| 1146 | {␍␊ |
| 1147 | png_warning(png_ptr,␍␊ |
| 1148 | "Truncating profile to actual length in iCCP chunk");␍␊ |
| 1149 | ␍␊ |
| 1150 | profile_len = embedded_profile_len;␍␊ |
| 1151 | }␍␊ |
| 1152 | ␍␊ |
| 1153 | if (profile_len)␍␊ |
| 1154 | profile_len = png_text_compress(png_ptr, profile,␍␊ |
| 1155 | (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);␍␊ |
| 1156 | ␍␊ |
| 1157 | /* Make sure we include the NULL after the name and the compression type */␍␊ |
| 1158 | png_write_chunk_header(png_ptr, png_iCCP,␍␊ |
| 1159 | (png_uint_32)(name_len + profile_len + 2));␍␊ |
| 1160 | ␍␊ |
| 1161 | new_name[name_len + 1] = 0x00;␍␊ |
| 1162 | ␍␊ |
| 1163 | png_write_chunk_data(png_ptr, (png_bytep)new_name,␍␊ |
| 1164 | (png_size_t)(name_len + 2));␍␊ |
| 1165 | ␍␊ |
| 1166 | if (profile_len)␍␊ |
| 1167 | {␍␊ |
| 1168 | png_write_compressed_data_out(png_ptr, &comp, profile_len);␍␊ |
| 1169 | }␍␊ |
| 1170 | ␍␊ |
| 1171 | png_write_chunk_end(png_ptr);␍␊ |
| 1172 | png_free(png_ptr, new_name);␍␊ |
| 1173 | }␍␊ |
| 1174 | #endif␍␊ |
| 1175 | ␍␊ |
| 1176 | #ifdef PNG_WRITE_sPLT_SUPPORTED␍␊ |
| 1177 | /* Write a sPLT chunk */␍␊ |
| 1178 | void /* PRIVATE */␍␊ |
| 1179 | png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette)␍␊ |
| 1180 | {␍␊ |
| 1181 | png_size_t name_len;␍␊ |
| 1182 | png_charp new_name;␍␊ |
| 1183 | png_byte entrybuf[10];␍␊ |
| 1184 | png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);␍␊ |
| 1185 | png_size_t palette_size = entry_size * spalette->nentries;␍␊ |
| 1186 | png_sPLT_entryp ep;␍␊ |
| 1187 | #ifndef PNG_POINTER_INDEXING_SUPPORTED␍␊ |
| 1188 | int i;␍␊ |
| 1189 | #endif␍␊ |
| 1190 | ␍␊ |
| 1191 | png_debug(1, "in png_write_sPLT");␍␊ |
| 1192 | ␍␊ |
| 1193 | if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)␍␊ |
| 1194 | return;␍␊ |
| 1195 | ␍␊ |
| 1196 | /* Make sure we include the NULL after the name */␍␊ |
| 1197 | png_write_chunk_header(png_ptr, png_sPLT,␍␊ |
| 1198 | (png_uint_32)(name_len + 2 + palette_size));␍␊ |
| 1199 | ␍␊ |
| 1200 | png_write_chunk_data(png_ptr, (png_bytep)new_name,␍␊ |
| 1201 | (png_size_t)(name_len + 1));␍␊ |
| 1202 | ␍␊ |
| 1203 | png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1);␍␊ |
| 1204 | ␍␊ |
| 1205 | /* Loop through each palette entry, writing appropriately */␍␊ |
| 1206 | #ifdef PNG_POINTER_INDEXING_SUPPORTED␍␊ |
| 1207 | for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)␍␊ |
| 1208 | {␍␊ |
| 1209 | if (spalette->depth == 8)␍␊ |
| 1210 | {␍␊ |
| 1211 | entrybuf[0] = (png_byte)ep->red;␍␊ |
| 1212 | entrybuf[1] = (png_byte)ep->green;␍␊ |
| 1213 | entrybuf[2] = (png_byte)ep->blue;␍␊ |
| 1214 | entrybuf[3] = (png_byte)ep->alpha;␍␊ |
| 1215 | png_save_uint_16(entrybuf + 4, ep->frequency);␍␊ |
| 1216 | }␍␊ |
| 1217 | ␍␊ |
| 1218 | else␍␊ |
| 1219 | {␍␊ |
| 1220 | png_save_uint_16(entrybuf + 0, ep->red);␍␊ |
| 1221 | png_save_uint_16(entrybuf + 2, ep->green);␍␊ |
| 1222 | png_save_uint_16(entrybuf + 4, ep->blue);␍␊ |
| 1223 | png_save_uint_16(entrybuf + 6, ep->alpha);␍␊ |
| 1224 | png_save_uint_16(entrybuf + 8, ep->frequency);␍␊ |
| 1225 | }␍␊ |
| 1226 | ␍␊ |
| 1227 | png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);␍␊ |
| 1228 | }␍␊ |
| 1229 | #else␍␊ |
| 1230 | ep=spalette->entries;␍␊ |
| 1231 | for (i = 0; i>spalette->nentries; i++)␍␊ |
| 1232 | {␍␊ |
| 1233 | if (spalette->depth == 8)␍␊ |
| 1234 | {␍␊ |
| 1235 | entrybuf[0] = (png_byte)ep[i].red;␍␊ |
| 1236 | entrybuf[1] = (png_byte)ep[i].green;␍␊ |
| 1237 | entrybuf[2] = (png_byte)ep[i].blue;␍␊ |
| 1238 | entrybuf[3] = (png_byte)ep[i].alpha;␍␊ |
| 1239 | png_save_uint_16(entrybuf + 4, ep[i].frequency);␍␊ |
| 1240 | }␍␊ |
| 1241 | ␍␊ |
| 1242 | else␍␊ |
| 1243 | {␍␊ |
| 1244 | png_save_uint_16(entrybuf + 0, ep[i].red);␍␊ |
| 1245 | png_save_uint_16(entrybuf + 2, ep[i].green);␍␊ |
| 1246 | png_save_uint_16(entrybuf + 4, ep[i].blue);␍␊ |
| 1247 | png_save_uint_16(entrybuf + 6, ep[i].alpha);␍␊ |
| 1248 | png_save_uint_16(entrybuf + 8, ep[i].frequency);␍␊ |
| 1249 | }␍␊ |
| 1250 | ␍␊ |
| 1251 | png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);␍␊ |
| 1252 | }␍␊ |
| 1253 | #endif␍␊ |
| 1254 | ␍␊ |
| 1255 | png_write_chunk_end(png_ptr);␍␊ |
| 1256 | png_free(png_ptr, new_name);␍␊ |
| 1257 | }␍␊ |
| 1258 | #endif␍␊ |
| 1259 | ␍␊ |
| 1260 | #ifdef PNG_WRITE_sBIT_SUPPORTED␍␊ |
| 1261 | /* Write the sBIT chunk */␍␊ |
| 1262 | void /* PRIVATE */␍␊ |
| 1263 | png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type)␍␊ |
| 1264 | {␍␊ |
| 1265 | png_byte buf[4];␍␊ |
| 1266 | png_size_t size;␍␊ |
| 1267 | ␍␊ |
| 1268 | png_debug(1, "in png_write_sBIT");␍␊ |
| 1269 | ␍␊ |
| 1270 | /* Make sure we don't depend upon the order of PNG_COLOR_8 */␍␊ |
| 1271 | if (color_type & PNG_COLOR_MASK_COLOR)␍␊ |
| 1272 | {␍␊ |
| 1273 | png_byte maxbits;␍␊ |
| 1274 | ␍␊ |
| 1275 | maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :␍␊ |
| 1276 | png_ptr->usr_bit_depth);␍␊ |
| 1277 | ␍␊ |
| 1278 | if (sbit->red == 0 || sbit->red > maxbits ||␍␊ |
| 1279 | sbit->green == 0 || sbit->green > maxbits ||␍␊ |
| 1280 | sbit->blue == 0 || sbit->blue > maxbits)␍␊ |
| 1281 | {␍␊ |
| 1282 | png_warning(png_ptr, "Invalid sBIT depth specified");␍␊ |
| 1283 | return;␍␊ |
| 1284 | }␍␊ |
| 1285 | ␍␊ |
| 1286 | buf[0] = sbit->red;␍␊ |
| 1287 | buf[1] = sbit->green;␍␊ |
| 1288 | buf[2] = sbit->blue;␍␊ |
| 1289 | size = 3;␍␊ |
| 1290 | }␍␊ |
| 1291 | ␍␊ |
| 1292 | else␍␊ |
| 1293 | {␍␊ |
| 1294 | if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)␍␊ |
| 1295 | {␍␊ |
| 1296 | png_warning(png_ptr, "Invalid sBIT depth specified");␍␊ |
| 1297 | return;␍␊ |
| 1298 | }␍␊ |
| 1299 | ␍␊ |
| 1300 | buf[0] = sbit->gray;␍␊ |
| 1301 | size = 1;␍␊ |
| 1302 | }␍␊ |
| 1303 | ␍␊ |
| 1304 | if (color_type & PNG_COLOR_MASK_ALPHA)␍␊ |
| 1305 | {␍␊ |
| 1306 | if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)␍␊ |
| 1307 | {␍␊ |
| 1308 | png_warning(png_ptr, "Invalid sBIT depth specified");␍␊ |
| 1309 | return;␍␊ |
| 1310 | }␍␊ |
| 1311 | ␍␊ |
| 1312 | buf[size++] = sbit->alpha;␍␊ |
| 1313 | }␍␊ |
| 1314 | ␍␊ |
| 1315 | png_write_complete_chunk(png_ptr, png_sBIT, buf, size);␍␊ |
| 1316 | }␍␊ |
| 1317 | #endif␍␊ |
| 1318 | ␍␊ |
| 1319 | #ifdef PNG_WRITE_cHRM_SUPPORTED␍␊ |
| 1320 | /* Write the cHRM chunk */␍␊ |
| 1321 | void /* PRIVATE */␍␊ |
| 1322 | png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,␍␊ |
| 1323 | png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,␍␊ |
| 1324 | png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,␍␊ |
| 1325 | png_fixed_point blue_y)␍␊ |
| 1326 | {␍␊ |
| 1327 | png_byte buf[32];␍␊ |
| 1328 | ␍␊ |
| 1329 | png_debug(1, "in png_write_cHRM");␍␊ |
| 1330 | ␍␊ |
| 1331 | /* Each value is saved in 1/100,000ths */␍␊ |
| 1332 | #ifdef PNG_CHECK_cHRM_SUPPORTED␍␊ |
| 1333 | if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,␍␊ |
| 1334 | green_x, green_y, blue_x, blue_y))␍␊ |
| 1335 | #endif␍␊ |
| 1336 | {␍␊ |
| 1337 | png_save_uint_32(buf, (png_uint_32)white_x);␍␊ |
| 1338 | png_save_uint_32(buf + 4, (png_uint_32)white_y);␍␊ |
| 1339 | ␍␊ |
| 1340 | png_save_uint_32(buf + 8, (png_uint_32)red_x);␍␊ |
| 1341 | png_save_uint_32(buf + 12, (png_uint_32)red_y);␍␊ |
| 1342 | ␍␊ |
| 1343 | png_save_uint_32(buf + 16, (png_uint_32)green_x);␍␊ |
| 1344 | png_save_uint_32(buf + 20, (png_uint_32)green_y);␍␊ |
| 1345 | ␍␊ |
| 1346 | png_save_uint_32(buf + 24, (png_uint_32)blue_x);␍␊ |
| 1347 | png_save_uint_32(buf + 28, (png_uint_32)blue_y);␍␊ |
| 1348 | ␍␊ |
| 1349 | png_write_complete_chunk(png_ptr, png_cHRM, buf, (png_size_t)32);␍␊ |
| 1350 | }␍␊ |
| 1351 | }␍␊ |
| 1352 | #endif␍␊ |
| 1353 | ␍␊ |
| 1354 | #ifdef PNG_WRITE_tRNS_SUPPORTED␍␊ |
| 1355 | /* Write the tRNS chunk */␍␊ |
| 1356 | void /* PRIVATE */␍␊ |
| 1357 | png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha,␍␊ |
| 1358 | png_const_color_16p tran, int num_trans, int color_type)␍␊ |
| 1359 | {␍␊ |
| 1360 | png_byte buf[6];␍␊ |
| 1361 | ␍␊ |
| 1362 | png_debug(1, "in png_write_tRNS");␍␊ |
| 1363 | ␍␊ |
| 1364 | if (color_type == PNG_COLOR_TYPE_PALETTE)␍␊ |
| 1365 | {␍␊ |
| 1366 | if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)␍␊ |
| 1367 | {␍␊ |
| 1368 | png_warning(png_ptr, "Invalid number of transparent colors specified");␍␊ |
| 1369 | return;␍␊ |
| 1370 | }␍␊ |
| 1371 | ␍␊ |
| 1372 | /* Write the chunk out as it is */␍␊ |
| 1373 | png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,␍␊ |
| 1374 | (png_size_t)num_trans);␍␊ |
| 1375 | }␍␊ |
| 1376 | ␍␊ |
| 1377 | else if (color_type == PNG_COLOR_TYPE_GRAY)␍␊ |
| 1378 | {␍␊ |
| 1379 | /* One 16 bit value */␍␊ |
| 1380 | if (tran->gray >= (1 << png_ptr->bit_depth))␍␊ |
| 1381 | {␍␊ |
| 1382 | png_warning(png_ptr,␍␊ |
| 1383 | "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");␍␊ |
| 1384 | ␍␊ |
| 1385 | return;␍␊ |
| 1386 | }␍␊ |
| 1387 | ␍␊ |
| 1388 | png_save_uint_16(buf, tran->gray);␍␊ |
| 1389 | png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);␍␊ |
| 1390 | }␍␊ |
| 1391 | ␍␊ |
| 1392 | else if (color_type == PNG_COLOR_TYPE_RGB)␍␊ |
| 1393 | {␍␊ |
| 1394 | /* Three 16 bit values */␍␊ |
| 1395 | png_save_uint_16(buf, tran->red);␍␊ |
| 1396 | png_save_uint_16(buf + 2, tran->green);␍␊ |
| 1397 | png_save_uint_16(buf + 4, tran->blue);␍␊ |
| 1398 | #ifdef PNG_WRITE_16BIT_SUPPORTED␍␊ |
| 1399 | if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))␍␊ |
| 1400 | #else␍␊ |
| 1401 | if (buf[0] | buf[2] | buf[4])␍␊ |
| 1402 | #endif␍␊ |
| 1403 | {␍␊ |
| 1404 | png_warning(png_ptr,␍␊ |
| 1405 | "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");␍␊ |
| 1406 | return;␍␊ |
| 1407 | }␍␊ |
| 1408 | ␍␊ |
| 1409 | png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);␍␊ |
| 1410 | }␍␊ |
| 1411 | ␍␊ |
| 1412 | else␍␊ |
| 1413 | {␍␊ |
| 1414 | png_warning(png_ptr, "Can't write tRNS with an alpha channel");␍␊ |
| 1415 | }␍␊ |
| 1416 | }␍␊ |
| 1417 | #endif␍␊ |
| 1418 | ␍␊ |
| 1419 | #ifdef PNG_WRITE_bKGD_SUPPORTED␍␊ |
| 1420 | /* Write the background chunk */␍␊ |
| 1421 | void /* PRIVATE */␍␊ |
| 1422 | png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type)␍␊ |
| 1423 | {␍␊ |
| 1424 | png_byte buf[6];␍␊ |
| 1425 | ␍␊ |
| 1426 | png_debug(1, "in png_write_bKGD");␍␊ |
| 1427 | ␍␊ |
| 1428 | if (color_type == PNG_COLOR_TYPE_PALETTE)␍␊ |
| 1429 | {␍␊ |
| 1430 | if (␍␊ |
| 1431 | #ifdef PNG_MNG_FEATURES_SUPPORTED␍␊ |
| 1432 | (png_ptr->num_palette ||␍␊ |
| 1433 | (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&␍␊ |
| 1434 | #endif␍␊ |
| 1435 | back->index >= png_ptr->num_palette)␍␊ |
| 1436 | {␍␊ |
| 1437 | png_warning(png_ptr, "Invalid background palette index");␍␊ |
| 1438 | return;␍␊ |
| 1439 | }␍␊ |
| 1440 | ␍␊ |
| 1441 | buf[0] = back->index;␍␊ |
| 1442 | png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);␍␊ |
| 1443 | }␍␊ |
| 1444 | ␍␊ |
| 1445 | else if (color_type & PNG_COLOR_MASK_COLOR)␍␊ |
| 1446 | {␍␊ |
| 1447 | png_save_uint_16(buf, back->red);␍␊ |
| 1448 | png_save_uint_16(buf + 2, back->green);␍␊ |
| 1449 | png_save_uint_16(buf + 4, back->blue);␍␊ |
| 1450 | #ifdef PNG_WRITE_16BIT_SUPPORTED␍␊ |
| 1451 | if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))␍␊ |
| 1452 | #else␍␊ |
| 1453 | if (buf[0] | buf[2] | buf[4])␍␊ |
| 1454 | #endif␍␊ |
| 1455 | {␍␊ |
| 1456 | png_warning(png_ptr,␍␊ |
| 1457 | "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");␍␊ |
| 1458 | ␍␊ |
| 1459 | return;␍␊ |
| 1460 | }␍␊ |
| 1461 | ␍␊ |
| 1462 | png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);␍␊ |
| 1463 | }␍␊ |
| 1464 | ␍␊ |
| 1465 | else␍␊ |
| 1466 | {␍␊ |
| 1467 | if (back->gray >= (1 << png_ptr->bit_depth))␍␊ |
| 1468 | {␍␊ |
| 1469 | png_warning(png_ptr,␍␊ |
| 1470 | "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");␍␊ |
| 1471 | ␍␊ |
| 1472 | return;␍␊ |
| 1473 | }␍␊ |
| 1474 | ␍␊ |
| 1475 | png_save_uint_16(buf, back->gray);␍␊ |
| 1476 | png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);␍␊ |
| 1477 | }␍␊ |
| 1478 | }␍␊ |
| 1479 | #endif␍␊ |
| 1480 | ␍␊ |
| 1481 | #ifdef PNG_WRITE_hIST_SUPPORTED␍␊ |
| 1482 | /* Write the histogram */␍␊ |
| 1483 | void /* PRIVATE */␍␊ |
| 1484 | png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist)␍␊ |
| 1485 | {␍␊ |
| 1486 | int i;␍␊ |
| 1487 | png_byte buf[3];␍␊ |
| 1488 | ␍␊ |
| 1489 | png_debug(1, "in png_write_hIST");␍␊ |
| 1490 | ␍␊ |
| 1491 | if (num_hist > (int)png_ptr->num_palette)␍␊ |
| 1492 | {␍␊ |
| 1493 | png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,␍␊ |
| 1494 | png_ptr->num_palette);␍␊ |
| 1495 | ␍␊ |
| 1496 | png_warning(png_ptr, "Invalid number of histogram entries specified");␍␊ |
| 1497 | return;␍␊ |
| 1498 | }␍␊ |
| 1499 | ␍␊ |
| 1500 | png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));␍␊ |
| 1501 | ␍␊ |
| 1502 | for (i = 0; i < num_hist; i++)␍␊ |
| 1503 | {␍␊ |
| 1504 | png_save_uint_16(buf, hist[i]);␍␊ |
| 1505 | png_write_chunk_data(png_ptr, buf, (png_size_t)2);␍␊ |
| 1506 | }␍␊ |
| 1507 | ␍␊ |
| 1508 | png_write_chunk_end(png_ptr);␍␊ |
| 1509 | }␍␊ |
| 1510 | #endif␍␊ |
| 1511 | ␍␊ |
| 1512 | #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \␍␊ |
| 1513 | defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)␍␊ |
| 1514 | /* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,␍␊ |
| 1515 | * and if invalid, correct the keyword rather than discarding the entire␍␊ |
| 1516 | * chunk. The PNG 1.0 specification requires keywords 1-79 characters in␍␊ |
| 1517 | * length, forbids leading or trailing whitespace, multiple internal spaces,␍␊ |
| 1518 | * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.␍␊ |
| 1519 | *␍␊ |
| 1520 | * The new_key is allocated to hold the corrected keyword and must be freed␍␊ |
| 1521 | * by the calling routine. This avoids problems with trying to write to␍␊ |
| 1522 | * static keywords without having to have duplicate copies of the strings.␍␊ |
| 1523 | */␍␊ |
| 1524 | png_size_t /* PRIVATE */␍␊ |
| 1525 | png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key)␍␊ |
| 1526 | {␍␊ |
| 1527 | png_size_t key_len;␍␊ |
| 1528 | png_const_charp ikp;␍␊ |
| 1529 | png_charp kp, dp;␍␊ |
| 1530 | int kflag;␍␊ |
| 1531 | int kwarn=0;␍␊ |
| 1532 | ␍␊ |
| 1533 | png_debug(1, "in png_check_keyword");␍␊ |
| 1534 | ␍␊ |
| 1535 | *new_key = NULL;␍␊ |
| 1536 | ␍␊ |
| 1537 | if (key == NULL || (key_len = png_strlen(key)) == 0)␍␊ |
| 1538 | {␍␊ |
| 1539 | png_warning(png_ptr, "zero length keyword");␍␊ |
| 1540 | return ((png_size_t)0);␍␊ |
| 1541 | }␍␊ |
| 1542 | ␍␊ |
| 1543 | png_debug1(2, "Keyword to be checked is '%s'", key);␍␊ |
| 1544 | ␍␊ |
| 1545 | *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));␍␊ |
| 1546 | ␍␊ |
| 1547 | if (*new_key == NULL)␍␊ |
| 1548 | {␍␊ |
| 1549 | png_warning(png_ptr, "Out of memory while procesing keyword");␍␊ |
| 1550 | return ((png_size_t)0);␍␊ |
| 1551 | }␍␊ |
| 1552 | ␍␊ |
| 1553 | /* Replace non-printing characters with a blank and print a warning */␍␊ |
| 1554 | for (ikp = key, dp = *new_key; *ikp != '\0'; ikp++, dp++)␍␊ |
| 1555 | {␍␊ |
| 1556 | if ((png_byte)*ikp < 0x20 ||␍␊ |
| 1557 | ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1))␍␊ |
| 1558 | {␍␊ |
| 1559 | PNG_WARNING_PARAMETERS(p)␍␊ |
| 1560 | ␍␊ |
| 1561 | png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_02x,␍␊ |
| 1562 | (png_byte)*ikp);␍␊ |
| 1563 | png_formatted_warning(png_ptr, p, "invalid keyword character 0x@1");␍␊ |
| 1564 | *dp = ' ';␍␊ |
| 1565 | }␍␊ |
| 1566 | ␍␊ |
| 1567 | else␍␊ |
| 1568 | {␍␊ |
| 1569 | *dp = *ikp;␍␊ |
| 1570 | }␍␊ |
| 1571 | }␍␊ |
| 1572 | *dp = '\0';␍␊ |
| 1573 | ␍␊ |
| 1574 | /* Remove any trailing white space. */␍␊ |
| 1575 | kp = *new_key + key_len - 1;␍␊ |
| 1576 | if (*kp == ' ')␍␊ |
| 1577 | {␍␊ |
| 1578 | png_warning(png_ptr, "trailing spaces removed from keyword");␍␊ |
| 1579 | ␍␊ |
| 1580 | while (*kp == ' ')␍␊ |
| 1581 | {␍␊ |
| 1582 | *(kp--) = '\0';␍␊ |
| 1583 | key_len--;␍␊ |
| 1584 | }␍␊ |
| 1585 | }␍␊ |
| 1586 | ␍␊ |
| 1587 | /* Remove any leading white space. */␍␊ |
| 1588 | kp = *new_key;␍␊ |
| 1589 | if (*kp == ' ')␍␊ |
| 1590 | {␍␊ |
| 1591 | png_warning(png_ptr, "leading spaces removed from keyword");␍␊ |
| 1592 | ␍␊ |
| 1593 | while (*kp == ' ')␍␊ |
| 1594 | {␍␊ |
| 1595 | kp++;␍␊ |
| 1596 | key_len--;␍␊ |
| 1597 | }␍␊ |
| 1598 | }␍␊ |
| 1599 | ␍␊ |
| 1600 | png_debug1(2, "Checking for multiple internal spaces in '%s'", kp);␍␊ |
| 1601 | ␍␊ |
| 1602 | /* Remove multiple internal spaces. */␍␊ |
| 1603 | for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)␍␊ |
| 1604 | {␍␊ |
| 1605 | if (*kp == ' ' && kflag == 0)␍␊ |
| 1606 | {␍␊ |
| 1607 | *(dp++) = *kp;␍␊ |
| 1608 | kflag = 1;␍␊ |
| 1609 | }␍␊ |
| 1610 | ␍␊ |
| 1611 | else if (*kp == ' ')␍␊ |
| 1612 | {␍␊ |
| 1613 | key_len--;␍␊ |
| 1614 | kwarn = 1;␍␊ |
| 1615 | }␍␊ |
| 1616 | ␍␊ |
| 1617 | else␍␊ |
| 1618 | {␍␊ |
| 1619 | *(dp++) = *kp;␍␊ |
| 1620 | kflag = 0;␍␊ |
| 1621 | }␍␊ |
| 1622 | }␍␊ |
| 1623 | *dp = '\0';␍␊ |
| 1624 | if (kwarn)␍␊ |
| 1625 | png_warning(png_ptr, "extra interior spaces removed from keyword");␍␊ |
| 1626 | ␍␊ |
| 1627 | if (key_len == 0)␍␊ |
| 1628 | {␍␊ |
| 1629 | png_free(png_ptr, *new_key);␍␊ |
| 1630 | png_warning(png_ptr, "Zero length keyword");␍␊ |
| 1631 | }␍␊ |
| 1632 | ␍␊ |
| 1633 | if (key_len > 79)␍␊ |
| 1634 | {␍␊ |
| 1635 | png_warning(png_ptr, "keyword length must be 1 - 79 characters");␍␊ |
| 1636 | (*new_key)[79] = '\0';␍␊ |
| 1637 | key_len = 79;␍␊ |
| 1638 | }␍␊ |
| 1639 | ␍␊ |
| 1640 | return (key_len);␍␊ |
| 1641 | }␍␊ |
| 1642 | #endif␍␊ |
| 1643 | ␍␊ |
| 1644 | #ifdef PNG_WRITE_tEXt_SUPPORTED␍␊ |
| 1645 | /* Write a tEXt chunk */␍␊ |
| 1646 | void /* PRIVATE */␍␊ |
| 1647 | png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text,␍␊ |
| 1648 | png_size_t text_len)␍␊ |
| 1649 | {␍␊ |
| 1650 | png_size_t key_len;␍␊ |
| 1651 | png_charp new_key;␍␊ |
| 1652 | ␍␊ |
| 1653 | png_debug(1, "in png_write_tEXt");␍␊ |
| 1654 | ␍␊ |
| 1655 | if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)␍␊ |
| 1656 | return;␍␊ |
| 1657 | ␍␊ |
| 1658 | if (text == NULL || *text == '\0')␍␊ |
| 1659 | text_len = 0;␍␊ |
| 1660 | ␍␊ |
| 1661 | else␍␊ |
| 1662 | text_len = png_strlen(text);␍␊ |
| 1663 | ␍␊ |
| 1664 | /* Make sure we include the 0 after the key */␍␊ |
| 1665 | png_write_chunk_header(png_ptr, png_tEXt,␍␊ |
| 1666 | (png_uint_32)(key_len + text_len + 1));␍␊ |
| 1667 | /*␍␊ |
| 1668 | * We leave it to the application to meet PNG-1.0 requirements on the␍␊ |
| 1669 | * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of␍␊ |
| 1670 | * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.␍␊ |
| 1671 | * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.␍␊ |
| 1672 | */␍␊ |
| 1673 | png_write_chunk_data(png_ptr, (png_bytep)new_key,␍␊ |
| 1674 | (png_size_t)(key_len + 1));␍␊ |
| 1675 | ␍␊ |
| 1676 | if (text_len)␍␊ |
| 1677 | png_write_chunk_data(png_ptr, (png_const_bytep)text,␍␊ |
| 1678 | (png_size_t)text_len);␍␊ |
| 1679 | ␍␊ |
| 1680 | png_write_chunk_end(png_ptr);␍␊ |
| 1681 | png_free(png_ptr, new_key);␍␊ |
| 1682 | }␍␊ |
| 1683 | #endif␍␊ |
| 1684 | ␍␊ |
| 1685 | #ifdef PNG_WRITE_zTXt_SUPPORTED␍␊ |
| 1686 | /* Write a compressed text chunk */␍␊ |
| 1687 | void /* PRIVATE */␍␊ |
| 1688 | png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text,␍␊ |
| 1689 | png_size_t text_len, int compression)␍␊ |
| 1690 | {␍␊ |
| 1691 | png_size_t key_len;␍␊ |
| 1692 | png_byte buf;␍␊ |
| 1693 | png_charp new_key;␍␊ |
| 1694 | compression_state comp;␍␊ |
| 1695 | ␍␊ |
| 1696 | png_debug(1, "in png_write_zTXt");␍␊ |
| 1697 | ␍␊ |
| 1698 | comp.num_output_ptr = 0;␍␊ |
| 1699 | comp.max_output_ptr = 0;␍␊ |
| 1700 | comp.output_ptr = NULL;␍␊ |
| 1701 | comp.input = NULL;␍␊ |
| 1702 | comp.input_len = 0;␍␊ |
| 1703 | ␍␊ |
| 1704 | if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0)␍␊ |
| 1705 | {␍␊ |
| 1706 | png_free(png_ptr, new_key);␍␊ |
| 1707 | return;␍␊ |
| 1708 | }␍␊ |
| 1709 | ␍␊ |
| 1710 | if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)␍␊ |
| 1711 | {␍␊ |
| 1712 | png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);␍␊ |
| 1713 | png_free(png_ptr, new_key);␍␊ |
| 1714 | return;␍␊ |
| 1715 | }␍␊ |
| 1716 | ␍␊ |
| 1717 | text_len = png_strlen(text);␍␊ |
| 1718 | ␍␊ |
| 1719 | /* Compute the compressed data; do it now for the length */␍␊ |
| 1720 | text_len = png_text_compress(png_ptr, text, text_len, compression,␍␊ |
| 1721 | &comp);␍␊ |
| 1722 | ␍␊ |
| 1723 | /* Write start of chunk */␍␊ |
| 1724 | png_write_chunk_header(png_ptr, png_zTXt,␍␊ |
| 1725 | (png_uint_32)(key_len+text_len + 2));␍␊ |
| 1726 | ␍␊ |
| 1727 | /* Write key */␍␊ |
| 1728 | png_write_chunk_data(png_ptr, (png_bytep)new_key,␍␊ |
| 1729 | (png_size_t)(key_len + 1));␍␊ |
| 1730 | ␍␊ |
| 1731 | png_free(png_ptr, new_key);␍␊ |
| 1732 | ␍␊ |
| 1733 | buf = (png_byte)compression;␍␊ |
| 1734 | ␍␊ |
| 1735 | /* Write compression */␍␊ |
| 1736 | png_write_chunk_data(png_ptr, &buf, (png_size_t)1);␍␊ |
| 1737 | ␍␊ |
| 1738 | /* Write the compressed data */␍␊ |
| 1739 | png_write_compressed_data_out(png_ptr, &comp, text_len);␍␊ |
| 1740 | ␍␊ |
| 1741 | /* Close the chunk */␍␊ |
| 1742 | png_write_chunk_end(png_ptr);␍␊ |
| 1743 | }␍␊ |
| 1744 | #endif␍␊ |
| 1745 | ␍␊ |
| 1746 | #ifdef PNG_WRITE_iTXt_SUPPORTED␍␊ |
| 1747 | /* Write an iTXt chunk */␍␊ |
| 1748 | void /* PRIVATE */␍␊ |
| 1749 | png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key,␍␊ |
| 1750 | png_const_charp lang, png_const_charp lang_key, png_const_charp text)␍␊ |
| 1751 | {␍␊ |
| 1752 | png_size_t lang_len, key_len, lang_key_len, text_len;␍␊ |
| 1753 | png_charp new_lang;␍␊ |
| 1754 | png_charp new_key = NULL;␍␊ |
| 1755 | png_byte cbuf[2];␍␊ |
| 1756 | compression_state comp;␍␊ |
| 1757 | ␍␊ |
| 1758 | png_debug(1, "in png_write_iTXt");␍␊ |
| 1759 | ␍␊ |
| 1760 | comp.num_output_ptr = 0;␍␊ |
| 1761 | comp.max_output_ptr = 0;␍␊ |
| 1762 | comp.output_ptr = NULL;␍␊ |
| 1763 | comp.input = NULL;␍␊ |
| 1764 | ␍␊ |
| 1765 | if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0)␍␊ |
| 1766 | return;␍␊ |
| 1767 | ␍␊ |
| 1768 | if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang)) == 0)␍␊ |
| 1769 | {␍␊ |
| 1770 | png_warning(png_ptr, "Empty language field in iTXt chunk");␍␊ |
| 1771 | new_lang = NULL;␍␊ |
| 1772 | lang_len = 0;␍␊ |
| 1773 | }␍␊ |
| 1774 | ␍␊ |
| 1775 | if (lang_key == NULL)␍␊ |
| 1776 | lang_key_len = 0;␍␊ |
| 1777 | ␍␊ |
| 1778 | else␍␊ |
| 1779 | lang_key_len = png_strlen(lang_key);␍␊ |
| 1780 | ␍␊ |
| 1781 | if (text == NULL)␍␊ |
| 1782 | text_len = 0;␍␊ |
| 1783 | ␍␊ |
| 1784 | else␍␊ |
| 1785 | text_len = png_strlen(text);␍␊ |
| 1786 | ␍␊ |
| 1787 | /* Compute the compressed data; do it now for the length */␍␊ |
| 1788 | text_len = png_text_compress(png_ptr, text, text_len, compression - 2,␍␊ |
| 1789 | &comp);␍␊ |
| 1790 | ␍␊ |
| 1791 | ␍␊ |
| 1792 | /* Make sure we include the compression flag, the compression byte,␍␊ |
| 1793 | * and the NULs after the key, lang, and lang_key parts␍␊ |
| 1794 | */␍␊ |
| 1795 | ␍␊ |
| 1796 | png_write_chunk_header(png_ptr, png_iTXt, (png_uint_32)(␍␊ |
| 1797 | 5 /* comp byte, comp flag, terminators for key, lang and lang_key */␍␊ |
| 1798 | + key_len␍␊ |
| 1799 | + lang_len␍␊ |
| 1800 | + lang_key_len␍␊ |
| 1801 | + text_len));␍␊ |
| 1802 | ␍␊ |
| 1803 | /* We leave it to the application to meet PNG-1.0 requirements on the␍␊ |
| 1804 | * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of␍␊ |
| 1805 | * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.␍␊ |
| 1806 | * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.␍␊ |
| 1807 | */␍␊ |
| 1808 | png_write_chunk_data(png_ptr, (png_bytep)new_key, (png_size_t)(key_len + 1));␍␊ |
| 1809 | ␍␊ |
| 1810 | /* Set the compression flag */␍␊ |
| 1811 | if (compression == PNG_ITXT_COMPRESSION_NONE ||␍␊ |
| 1812 | compression == PNG_TEXT_COMPRESSION_NONE)␍␊ |
| 1813 | cbuf[0] = 0;␍␊ |
| 1814 | ␍␊ |
| 1815 | else /* compression == PNG_ITXT_COMPRESSION_zTXt */␍␊ |
| 1816 | cbuf[0] = 1;␍␊ |
| 1817 | ␍␊ |
| 1818 | /* Set the compression method */␍␊ |
| 1819 | cbuf[1] = 0;␍␊ |
| 1820 | ␍␊ |
| 1821 | png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);␍␊ |
| 1822 | ␍␊ |
| 1823 | cbuf[0] = 0;␍␊ |
| 1824 | png_write_chunk_data(png_ptr, (new_lang ? (png_const_bytep)new_lang : cbuf),␍␊ |
| 1825 | (png_size_t)(lang_len + 1));␍␊ |
| 1826 | ␍␊ |
| 1827 | png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf),␍␊ |
| 1828 | (png_size_t)(lang_key_len + 1));␍␊ |
| 1829 | ␍␊ |
| 1830 | png_write_compressed_data_out(png_ptr, &comp, text_len);␍␊ |
| 1831 | ␍␊ |
| 1832 | png_write_chunk_end(png_ptr);␍␊ |
| 1833 | ␍␊ |
| 1834 | png_free(png_ptr, new_key);␍␊ |
| 1835 | png_free(png_ptr, new_lang);␍␊ |
| 1836 | }␍␊ |
| 1837 | #endif␍␊ |
| 1838 | ␍␊ |
| 1839 | #ifdef PNG_WRITE_oFFs_SUPPORTED␍␊ |
| 1840 | /* Write the oFFs chunk */␍␊ |
| 1841 | void /* PRIVATE */␍␊ |
| 1842 | png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,␍␊ |
| 1843 | int unit_type)␍␊ |
| 1844 | {␍␊ |
| 1845 | png_byte buf[9];␍␊ |
| 1846 | ␍␊ |
| 1847 | png_debug(1, "in png_write_oFFs");␍␊ |
| 1848 | ␍␊ |
| 1849 | if (unit_type >= PNG_OFFSET_LAST)␍␊ |
| 1850 | png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");␍␊ |
| 1851 | ␍␊ |
| 1852 | png_save_int_32(buf, x_offset);␍␊ |
| 1853 | png_save_int_32(buf + 4, y_offset);␍␊ |
| 1854 | buf[8] = (png_byte)unit_type;␍␊ |
| 1855 | ␍␊ |
| 1856 | png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);␍␊ |
| 1857 | }␍␊ |
| 1858 | #endif␍␊ |
| 1859 | #ifdef PNG_WRITE_pCAL_SUPPORTED␍␊ |
| 1860 | /* Write the pCAL chunk (described in the PNG extensions document) */␍␊ |
| 1861 | void /* PRIVATE */␍␊ |
| 1862 | png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,␍␊ |
| 1863 | png_int_32 X1, int type, int nparams, png_const_charp units,␍␊ |
| 1864 | png_charpp params)␍␊ |
| 1865 | {␍␊ |
| 1866 | png_size_t purpose_len, units_len, total_len;␍␊ |
| 1867 | png_size_tp params_len;␍␊ |
| 1868 | png_byte buf[10];␍␊ |
| 1869 | png_charp new_purpose;␍␊ |
| 1870 | int i;␍␊ |
| 1871 | ␍␊ |
| 1872 | png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);␍␊ |
| 1873 | ␍␊ |
| 1874 | if (type >= PNG_EQUATION_LAST)␍␊ |
| 1875 | png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");␍␊ |
| 1876 | ␍␊ |
| 1877 | purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;␍␊ |
| 1878 | png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);␍␊ |
| 1879 | units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);␍␊ |
| 1880 | png_debug1(3, "pCAL units length = %d", (int)units_len);␍␊ |
| 1881 | total_len = purpose_len + units_len + 10;␍␊ |
| 1882 | ␍␊ |
| 1883 | params_len = (png_size_tp)png_malloc(png_ptr,␍␊ |
| 1884 | (png_alloc_size_t)(nparams * png_sizeof(png_size_t)));␍␊ |
| 1885 | ␍␊ |
| 1886 | /* Find the length of each parameter, making sure we don't count the␍␊ |
| 1887 | * null terminator for the last parameter.␍␊ |
| 1888 | */␍␊ |
| 1889 | for (i = 0; i < nparams; i++)␍␊ |
| 1890 | {␍␊ |
| 1891 | params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);␍␊ |
| 1892 | png_debug2(3, "pCAL parameter %d length = %lu", i,␍␊ |
| 1893 | (unsigned long)params_len[i]);␍␊ |
| 1894 | total_len += params_len[i];␍␊ |
| 1895 | }␍␊ |
| 1896 | ␍␊ |
| 1897 | png_debug1(3, "pCAL total length = %d", (int)total_len);␍␊ |
| 1898 | png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);␍␊ |
| 1899 | png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, purpose_len);␍␊ |
| 1900 | png_save_int_32(buf, X0);␍␊ |
| 1901 | png_save_int_32(buf + 4, X1);␍␊ |
| 1902 | buf[8] = (png_byte)type;␍␊ |
| 1903 | buf[9] = (png_byte)nparams;␍␊ |
| 1904 | png_write_chunk_data(png_ptr, buf, (png_size_t)10);␍␊ |
| 1905 | png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len);␍␊ |
| 1906 | ␍␊ |
| 1907 | png_free(png_ptr, new_purpose);␍␊ |
| 1908 | ␍␊ |
| 1909 | for (i = 0; i < nparams; i++)␍␊ |
| 1910 | {␍␊ |
| 1911 | png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);␍␊ |
| 1912 | }␍␊ |
| 1913 | ␍␊ |
| 1914 | png_free(png_ptr, params_len);␍␊ |
| 1915 | png_write_chunk_end(png_ptr);␍␊ |
| 1916 | }␍␊ |
| 1917 | #endif␍␊ |
| 1918 | ␍␊ |
| 1919 | #ifdef PNG_WRITE_sCAL_SUPPORTED␍␊ |
| 1920 | /* Write the sCAL chunk */␍␊ |
| 1921 | void /* PRIVATE */␍␊ |
| 1922 | png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width,␍␊ |
| 1923 | png_const_charp height)␍␊ |
| 1924 | {␍␊ |
| 1925 | png_byte buf[64];␍␊ |
| 1926 | png_size_t wlen, hlen, total_len;␍␊ |
| 1927 | ␍␊ |
| 1928 | png_debug(1, "in png_write_sCAL_s");␍␊ |
| 1929 | ␍␊ |
| 1930 | wlen = png_strlen(width);␍␊ |
| 1931 | hlen = png_strlen(height);␍␊ |
| 1932 | total_len = wlen + hlen + 2;␍␊ |
| 1933 | ␍␊ |
| 1934 | if (total_len > 64)␍␊ |
| 1935 | {␍␊ |
| 1936 | png_warning(png_ptr, "Can't write sCAL (buffer too small)");␍␊ |
| 1937 | return;␍␊ |
| 1938 | }␍␊ |
| 1939 | ␍␊ |
| 1940 | buf[0] = (png_byte)unit;␍␊ |
| 1941 | png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */␍␊ |
| 1942 | png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */␍␊ |
| 1943 | ␍␊ |
| 1944 | png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);␍␊ |
| 1945 | png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);␍␊ |
| 1946 | }␍␊ |
| 1947 | #endif␍␊ |
| 1948 | ␍␊ |
| 1949 | #ifdef PNG_WRITE_pHYs_SUPPORTED␍␊ |
| 1950 | /* Write the pHYs chunk */␍␊ |
| 1951 | void /* PRIVATE */␍␊ |
| 1952 | png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,␍␊ |
| 1953 | png_uint_32 y_pixels_per_unit,␍␊ |
| 1954 | int unit_type)␍␊ |
| 1955 | {␍␊ |
| 1956 | png_byte buf[9];␍␊ |
| 1957 | ␍␊ |
| 1958 | png_debug(1, "in png_write_pHYs");␍␊ |
| 1959 | ␍␊ |
| 1960 | if (unit_type >= PNG_RESOLUTION_LAST)␍␊ |
| 1961 | png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");␍␊ |
| 1962 | ␍␊ |
| 1963 | png_save_uint_32(buf, x_pixels_per_unit);␍␊ |
| 1964 | png_save_uint_32(buf + 4, y_pixels_per_unit);␍␊ |
| 1965 | buf[8] = (png_byte)unit_type;␍␊ |
| 1966 | ␍␊ |
| 1967 | png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);␍␊ |
| 1968 | }␍␊ |
| 1969 | #endif␍␊ |
| 1970 | ␍␊ |
| 1971 | #ifdef PNG_WRITE_tIME_SUPPORTED␍␊ |
| 1972 | /* Write the tIME chunk. Use either png_convert_from_struct_tm()␍␊ |
| 1973 | * or png_convert_from_time_t(), or fill in the structure yourself.␍␊ |
| 1974 | */␍␊ |
| 1975 | void /* PRIVATE */␍␊ |
| 1976 | png_write_tIME(png_structp png_ptr, png_const_timep mod_time)␍␊ |
| 1977 | {␍␊ |
| 1978 | png_byte buf[7];␍␊ |
| 1979 | ␍␊ |
| 1980 | png_debug(1, "in png_write_tIME");␍␊ |
| 1981 | ␍␊ |
| 1982 | if (mod_time->month > 12 || mod_time->month < 1 ||␍␊ |
| 1983 | mod_time->day > 31 || mod_time->day < 1 ||␍␊ |
| 1984 | mod_time->hour > 23 || mod_time->second > 60)␍␊ |
| 1985 | {␍␊ |
| 1986 | png_warning(png_ptr, "Invalid time specified for tIME chunk");␍␊ |
| 1987 | return;␍␊ |
| 1988 | }␍␊ |
| 1989 | ␍␊ |
| 1990 | png_save_uint_16(buf, mod_time->year);␍␊ |
| 1991 | buf[2] = mod_time->month;␍␊ |
| 1992 | buf[3] = mod_time->day;␍␊ |
| 1993 | buf[4] = mod_time->hour;␍␊ |
| 1994 | buf[5] = mod_time->minute;␍␊ |
| 1995 | buf[6] = mod_time->second;␍␊ |
| 1996 | ␍␊ |
| 1997 | png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7);␍␊ |
| 1998 | }␍␊ |
| 1999 | #endif␍␊ |
| 2000 | ␍␊ |
| 2001 | /* Initializes the row writing capability of libpng */␍␊ |
| 2002 | void /* PRIVATE */␍␊ |
| 2003 | png_write_start_row(png_structp png_ptr)␍␊ |
| 2004 | {␍␊ |
| 2005 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED␍␊ |
| 2006 | /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */␍␊ |
| 2007 | ␍␊ |
| 2008 | /* Start of interlace block */␍␊ |
| 2009 | static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};␍␊ |
| 2010 | ␍␊ |
| 2011 | /* Offset to next interlace block */␍␊ |
| 2012 | static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};␍␊ |
| 2013 | ␍␊ |
| 2014 | /* Start of interlace block in the y direction */␍␊ |
| 2015 | static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};␍␊ |
| 2016 | ␍␊ |
| 2017 | /* Offset to next interlace block in the y direction */␍␊ |
| 2018 | static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};␍␊ |
| 2019 | #endif␍␊ |
| 2020 | ␍␊ |
| 2021 | png_alloc_size_t buf_size;␍␊ |
| 2022 | int usr_pixel_depth;␍␊ |
| 2023 | ␍␊ |
| 2024 | png_debug(1, "in png_write_start_row");␍␊ |
| 2025 | ␍␊ |
| 2026 | usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;␍␊ |
| 2027 | buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;␍␊ |
| 2028 | ␍␊ |
| 2029 | /* 1.5.6: added to allow checking in the row write code. */␍␊ |
| 2030 | png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;␍␊ |
| 2031 | png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;␍␊ |
| 2032 | ␍␊ |
| 2033 | /* Set up row buffer */␍␊ |
| 2034 | png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size);␍␊ |
| 2035 | ␍␊ |
| 2036 | png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;␍␊ |
| 2037 | ␍␊ |
| 2038 | #ifdef PNG_WRITE_FILTER_SUPPORTED␍␊ |
| 2039 | /* Set up filtering buffer, if using this filter */␍␊ |
| 2040 | if (png_ptr->do_filter & PNG_FILTER_SUB)␍␊ |
| 2041 | {␍␊ |
| 2042 | png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);␍␊ |
| 2043 | ␍␊ |
| 2044 | png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;␍␊ |
| 2045 | }␍␊ |
| 2046 | ␍␊ |
| 2047 | /* We only need to keep the previous row if we are using one of these. */␍␊ |
| 2048 | if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))␍␊ |
| 2049 | {␍␊ |
| 2050 | /* Set up previous row buffer */␍␊ |
| 2051 | png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size);␍␊ |
| 2052 | ␍␊ |
| 2053 | if (png_ptr->do_filter & PNG_FILTER_UP)␍␊ |
| 2054 | {␍␊ |
| 2055 | png_ptr->up_row = (png_bytep)png_malloc(png_ptr,␍␊ |
| 2056 | png_ptr->rowbytes + 1);␍␊ |
| 2057 | ␍␊ |
| 2058 | png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;␍␊ |
| 2059 | }␍␊ |
| 2060 | ␍␊ |
| 2061 | if (png_ptr->do_filter & PNG_FILTER_AVG)␍␊ |
| 2062 | {␍␊ |
| 2063 | png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,␍␊ |
| 2064 | png_ptr->rowbytes + 1);␍␊ |
| 2065 | ␍␊ |
| 2066 | png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;␍␊ |
| 2067 | }␍␊ |
| 2068 | ␍␊ |
| 2069 | if (png_ptr->do_filter & PNG_FILTER_PAETH)␍␊ |
| 2070 | {␍␊ |
| 2071 | png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,␍␊ |
| 2072 | png_ptr->rowbytes + 1);␍␊ |
| 2073 | ␍␊ |
| 2074 | png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;␍␊ |
| 2075 | }␍␊ |
| 2076 | }␍␊ |
| 2077 | #endif /* PNG_WRITE_FILTER_SUPPORTED */␍␊ |
| 2078 | ␍␊ |
| 2079 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED␍␊ |
| 2080 | /* If interlaced, we need to set up width and height of pass */␍␊ |
| 2081 | if (png_ptr->interlaced)␍␊ |
| 2082 | {␍␊ |
| 2083 | if (!(png_ptr->transformations & PNG_INTERLACE))␍␊ |
| 2084 | {␍␊ |
| 2085 | png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -␍␊ |
| 2086 | png_pass_ystart[0]) / png_pass_yinc[0];␍␊ |
| 2087 | ␍␊ |
| 2088 | png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -␍␊ |
| 2089 | png_pass_start[0]) / png_pass_inc[0];␍␊ |
| 2090 | }␍␊ |
| 2091 | ␍␊ |
| 2092 | else␍␊ |
| 2093 | {␍␊ |
| 2094 | png_ptr->num_rows = png_ptr->height;␍␊ |
| 2095 | png_ptr->usr_width = png_ptr->width;␍␊ |
| 2096 | }␍␊ |
| 2097 | }␍␊ |
| 2098 | ␍␊ |
| 2099 | else␍␊ |
| 2100 | #endif␍␊ |
| 2101 | {␍␊ |
| 2102 | png_ptr->num_rows = png_ptr->height;␍␊ |
| 2103 | png_ptr->usr_width = png_ptr->width;␍␊ |
| 2104 | }␍␊ |
| 2105 | ␍␊ |
| 2106 | png_zlib_claim(png_ptr, PNG_ZLIB_FOR_IDAT);␍␊ |
| 2107 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;␍␊ |
| 2108 | png_ptr->zstream.next_out = png_ptr->zbuf;␍␊ |
| 2109 | }␍␊ |
| 2110 | ␍␊ |
| 2111 | /* Internal use only. Called when finished processing a row of data. */␍␊ |
| 2112 | void /* PRIVATE */␍␊ |
| 2113 | png_write_finish_row(png_structp png_ptr)␍␊ |
| 2114 | {␍␊ |
| 2115 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED␍␊ |
| 2116 | /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */␍␊ |
| 2117 | ␍␊ |
| 2118 | /* Start of interlace block */␍␊ |
| 2119 | static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};␍␊ |
| 2120 | ␍␊ |
| 2121 | /* Offset to next interlace block */␍␊ |
| 2122 | static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};␍␊ |
| 2123 | ␍␊ |
| 2124 | /* Start of interlace block in the y direction */␍␊ |
| 2125 | static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};␍␊ |
| 2126 | ␍␊ |
| 2127 | /* Offset to next interlace block in the y direction */␍␊ |
| 2128 | static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};␍␊ |
| 2129 | #endif␍␊ |
| 2130 | ␍␊ |
| 2131 | int ret;␍␊ |
| 2132 | ␍␊ |
| 2133 | png_debug(1, "in png_write_finish_row");␍␊ |
| 2134 | ␍␊ |
| 2135 | /* Next row */␍␊ |
| 2136 | png_ptr->row_number++;␍␊ |
| 2137 | ␍␊ |
| 2138 | /* See if we are done */␍␊ |
| 2139 | if (png_ptr->row_number < png_ptr->num_rows)␍␊ |
| 2140 | return;␍␊ |
| 2141 | ␍␊ |
| 2142 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED␍␊ |
| 2143 | /* If interlaced, go to next pass */␍␊ |
| 2144 | if (png_ptr->interlaced)␍␊ |
| 2145 | {␍␊ |
| 2146 | png_ptr->row_number = 0;␍␊ |
| 2147 | if (png_ptr->transformations & PNG_INTERLACE)␍␊ |
| 2148 | {␍␊ |
| 2149 | png_ptr->pass++;␍␊ |
| 2150 | }␍␊ |
| 2151 | ␍␊ |
| 2152 | else␍␊ |
| 2153 | {␍␊ |
| 2154 | /* Loop until we find a non-zero width or height pass */␍␊ |
| 2155 | do␍␊ |
| 2156 | {␍␊ |
| 2157 | png_ptr->pass++;␍␊ |
| 2158 | ␍␊ |
| 2159 | if (png_ptr->pass >= 7)␍␊ |
| 2160 | break;␍␊ |
| 2161 | ␍␊ |
| 2162 | png_ptr->usr_width = (png_ptr->width +␍␊ |
| 2163 | png_pass_inc[png_ptr->pass] - 1 -␍␊ |
| 2164 | png_pass_start[png_ptr->pass]) /␍␊ |
| 2165 | png_pass_inc[png_ptr->pass];␍␊ |
| 2166 | ␍␊ |
| 2167 | png_ptr->num_rows = (png_ptr->height +␍␊ |
| 2168 | png_pass_yinc[png_ptr->pass] - 1 -␍␊ |
| 2169 | png_pass_ystart[png_ptr->pass]) /␍␊ |
| 2170 | png_pass_yinc[png_ptr->pass];␍␊ |
| 2171 | ␍␊ |
| 2172 | if (png_ptr->transformations & PNG_INTERLACE)␍␊ |
| 2173 | break;␍␊ |
| 2174 | ␍␊ |
| 2175 | } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);␍␊ |
| 2176 | ␍␊ |
| 2177 | }␍␊ |
| 2178 | ␍␊ |
| 2179 | /* Reset the row above the image for the next pass */␍␊ |
| 2180 | if (png_ptr->pass < 7)␍␊ |
| 2181 | {␍␊ |
| 2182 | if (png_ptr->prev_row != NULL)␍␊ |
| 2183 | png_memset(png_ptr->prev_row, 0,␍␊ |
| 2184 | (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*␍␊ |
| 2185 | png_ptr->usr_bit_depth, png_ptr->width)) + 1);␍␊ |
| 2186 | ␍␊ |
| 2187 | return;␍␊ |
| 2188 | }␍␊ |
| 2189 | }␍␊ |
| 2190 | #endif␍␊ |
| 2191 | ␍␊ |
| 2192 | /* If we get here, we've just written the last row, so we need␍␊ |
| 2193 | to flush the compressor */␍␊ |
| 2194 | do␍␊ |
| 2195 | {␍␊ |
| 2196 | /* Tell the compressor we are done */␍␊ |
| 2197 | ret = deflate(&png_ptr->zstream, Z_FINISH);␍␊ |
| 2198 | ␍␊ |
| 2199 | /* Check for an error */␍␊ |
| 2200 | if (ret == Z_OK)␍␊ |
| 2201 | {␍␊ |
| 2202 | /* Check to see if we need more room */␍␊ |
| 2203 | if (!(png_ptr->zstream.avail_out))␍␊ |
| 2204 | {␍␊ |
| 2205 | png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);␍␊ |
| 2206 | png_ptr->zstream.next_out = png_ptr->zbuf;␍␊ |
| 2207 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;␍␊ |
| 2208 | }␍␊ |
| 2209 | }␍␊ |
| 2210 | ␍␊ |
| 2211 | else if (ret != Z_STREAM_END)␍␊ |
| 2212 | {␍␊ |
| 2213 | if (png_ptr->zstream.msg != NULL)␍␊ |
| 2214 | png_error(png_ptr, png_ptr->zstream.msg);␍␊ |
| 2215 | ␍␊ |
| 2216 | else␍␊ |
| 2217 | png_error(png_ptr, "zlib error");␍␊ |
| 2218 | }␍␊ |
| 2219 | } while (ret != Z_STREAM_END);␍␊ |
| 2220 | ␍␊ |
| 2221 | /* Write any extra space */␍␊ |
| 2222 | if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)␍␊ |
| 2223 | {␍␊ |
| 2224 | png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -␍␊ |
| 2225 | png_ptr->zstream.avail_out);␍␊ |
| 2226 | }␍␊ |
| 2227 | ␍␊ |
| 2228 | png_zlib_release(png_ptr);␍␊ |
| 2229 | png_ptr->zstream.data_type = Z_BINARY;␍␊ |
| 2230 | }␍␊ |
| 2231 | ␍␊ |
| 2232 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED␍␊ |
| 2233 | /* Pick out the correct pixels for the interlace pass.␍␊ |
| 2234 | * The basic idea here is to go through the row with a source␍␊ |
| 2235 | * pointer and a destination pointer (sp and dp), and copy the␍␊ |
| 2236 | * correct pixels for the pass. As the row gets compacted,␍␊ |
| 2237 | * sp will always be >= dp, so we should never overwrite anything.␍␊ |
| 2238 | * See the default: case for the easiest code to understand.␍␊ |
| 2239 | */␍␊ |
| 2240 | void /* PRIVATE */␍␊ |
| 2241 | png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)␍␊ |
| 2242 | {␍␊ |
| 2243 | /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */␍␊ |
| 2244 | ␍␊ |
| 2245 | /* Start of interlace block */␍␊ |
| 2246 | static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};␍␊ |
| 2247 | ␍␊ |
| 2248 | /* Offset to next interlace block */␍␊ |
| 2249 | static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};␍␊ |
| 2250 | ␍␊ |
| 2251 | png_debug(1, "in png_do_write_interlace");␍␊ |
| 2252 | ␍␊ |
| 2253 | /* We don't have to do anything on the last pass (6) */␍␊ |
| 2254 | if (pass < 6)␍␊ |
| 2255 | {␍␊ |
| 2256 | /* Each pixel depth is handled separately */␍␊ |
| 2257 | switch (row_info->pixel_depth)␍␊ |
| 2258 | {␍␊ |
| 2259 | case 1:␍␊ |
| 2260 | {␍␊ |
| 2261 | png_bytep sp;␍␊ |
| 2262 | png_bytep dp;␍␊ |
| 2263 | int shift;␍␊ |
| 2264 | int d;␍␊ |
| 2265 | int value;␍␊ |
| 2266 | png_uint_32 i;␍␊ |
| 2267 | png_uint_32 row_width = row_info->width;␍␊ |
| 2268 | ␍␊ |
| 2269 | dp = row;␍␊ |
| 2270 | d = 0;␍␊ |
| 2271 | shift = 7;␍␊ |
| 2272 | ␍␊ |
| 2273 | for (i = png_pass_start[pass]; i < row_width;␍␊ |
| 2274 | i += png_pass_inc[pass])␍␊ |
| 2275 | {␍␊ |
| 2276 | sp = row + (png_size_t)(i >> 3);␍␊ |
| 2277 | value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;␍␊ |
| 2278 | d |= (value << shift);␍␊ |
| 2279 | ␍␊ |
| 2280 | if (shift == 0)␍␊ |
| 2281 | {␍␊ |
| 2282 | shift = 7;␍␊ |
| 2283 | *dp++ = (png_byte)d;␍␊ |
| 2284 | d = 0;␍␊ |
| 2285 | }␍␊ |
| 2286 | ␍␊ |
| 2287 | else␍␊ |
| 2288 | shift--;␍␊ |
| 2289 | ␍␊ |
| 2290 | }␍␊ |
| 2291 | if (shift != 7)␍␊ |
| 2292 | *dp = (png_byte)d;␍␊ |
| 2293 | ␍␊ |
| 2294 | break;␍␊ |
| 2295 | }␍␊ |
| 2296 | ␍␊ |
| 2297 | case 2:␍␊ |
| 2298 | {␍␊ |
| 2299 | png_bytep sp;␍␊ |
| 2300 | png_bytep dp;␍␊ |
| 2301 | int shift;␍␊ |
| 2302 | int d;␍␊ |
| 2303 | int value;␍␊ |
| 2304 | png_uint_32 i;␍␊ |
| 2305 | png_uint_32 row_width = row_info->width;␍␊ |
| 2306 | ␍␊ |
| 2307 | dp = row;␍␊ |
| 2308 | shift = 6;␍␊ |
| 2309 | d = 0;␍␊ |
| 2310 | ␍␊ |
| 2311 | for (i = png_pass_start[pass]; i < row_width;␍␊ |
| 2312 | i += png_pass_inc[pass])␍␊ |
| 2313 | {␍␊ |
| 2314 | sp = row + (png_size_t)(i >> 2);␍␊ |
| 2315 | value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;␍␊ |
| 2316 | d |= (value << shift);␍␊ |
| 2317 | ␍␊ |
| 2318 | if (shift == 0)␍␊ |
| 2319 | {␍␊ |
| 2320 | shift = 6;␍␊ |
| 2321 | *dp++ = (png_byte)d;␍␊ |
| 2322 | d = 0;␍␊ |
| 2323 | }␍␊ |
| 2324 | ␍␊ |
| 2325 | else␍␊ |
| 2326 | shift -= 2;␍␊ |
| 2327 | }␍␊ |
| 2328 | if (shift != 6)␍␊ |
| 2329 | *dp = (png_byte)d;␍␊ |
| 2330 | ␍␊ |
| 2331 | break;␍␊ |
| 2332 | }␍␊ |
| 2333 | ␍␊ |
| 2334 | case 4:␍␊ |
| 2335 | {␍␊ |
| 2336 | png_bytep sp;␍␊ |
| 2337 | png_bytep dp;␍␊ |
| 2338 | int shift;␍␊ |
| 2339 | int d;␍␊ |
| 2340 | int value;␍␊ |
| 2341 | png_uint_32 i;␍␊ |
| 2342 | png_uint_32 row_width = row_info->width;␍␊ |
| 2343 | ␍␊ |
| 2344 | dp = row;␍␊ |
| 2345 | shift = 4;␍␊ |
| 2346 | d = 0;␍␊ |
| 2347 | for (i = png_pass_start[pass]; i < row_width;␍␊ |
| 2348 | i += png_pass_inc[pass])␍␊ |
| 2349 | {␍␊ |
| 2350 | sp = row + (png_size_t)(i >> 1);␍␊ |
| 2351 | value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;␍␊ |
| 2352 | d |= (value << shift);␍␊ |
| 2353 | ␍␊ |
| 2354 | if (shift == 0)␍␊ |
| 2355 | {␍␊ |
| 2356 | shift = 4;␍␊ |
| 2357 | *dp++ = (png_byte)d;␍␊ |
| 2358 | d = 0;␍␊ |
| 2359 | }␍␊ |
| 2360 | ␍␊ |
| 2361 | else␍␊ |
| 2362 | shift -= 4;␍␊ |
| 2363 | }␍␊ |
| 2364 | if (shift != 4)␍␊ |
| 2365 | *dp = (png_byte)d;␍␊ |
| 2366 | ␍␊ |
| 2367 | break;␍␊ |
| 2368 | }␍␊ |
| 2369 | ␍␊ |
| 2370 | default:␍␊ |
| 2371 | {␍␊ |
| 2372 | png_bytep sp;␍␊ |
| 2373 | png_bytep dp;␍␊ |
| 2374 | png_uint_32 i;␍␊ |
| 2375 | png_uint_32 row_width = row_info->width;␍␊ |
| 2376 | png_size_t pixel_bytes;␍␊ |
| 2377 | ␍␊ |
| 2378 | /* Start at the beginning */␍␊ |
| 2379 | dp = row;␍␊ |
| 2380 | ␍␊ |
| 2381 | /* Find out how many bytes each pixel takes up */␍␊ |
| 2382 | pixel_bytes = (row_info->pixel_depth >> 3);␍␊ |
| 2383 | ␍␊ |
| 2384 | /* Loop through the row, only looking at the pixels that matter */␍␊ |
| 2385 | for (i = png_pass_start[pass]; i < row_width;␍␊ |
| 2386 | i += png_pass_inc[pass])␍␊ |
| 2387 | {␍␊ |
| 2388 | /* Find out where the original pixel is */␍␊ |
| 2389 | sp = row + (png_size_t)i * pixel_bytes;␍␊ |
| 2390 | ␍␊ |
| 2391 | /* Move the pixel */␍␊ |
| 2392 | if (dp != sp)␍␊ |
| 2393 | png_memcpy(dp, sp, pixel_bytes);␍␊ |
| 2394 | ␍␊ |
| 2395 | /* Next pixel */␍␊ |
| 2396 | dp += pixel_bytes;␍␊ |
| 2397 | }␍␊ |
| 2398 | break;␍␊ |
| 2399 | }␍␊ |
| 2400 | }␍␊ |
| 2401 | /* Set new row width */␍␊ |
| 2402 | row_info->width = (row_info->width +␍␊ |
| 2403 | png_pass_inc[pass] - 1 -␍␊ |
| 2404 | png_pass_start[pass]) /␍␊ |
| 2405 | png_pass_inc[pass];␍␊ |
| 2406 | ␍␊ |
| 2407 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,␍␊ |
| 2408 | row_info->width);␍␊ |
| 2409 | }␍␊ |
| 2410 | }␍␊ |
| 2411 | #endif␍␊ |
| 2412 | ␍␊ |
| 2413 | /* This filters the row, chooses which filter to use, if it has not already␍␊ |
| 2414 | * been specified by the application, and then writes the row out with the␍␊ |
| 2415 | * chosen filter.␍␊ |
| 2416 | */␍␊ |
| 2417 | static void png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row,␍␊ |
| 2418 | png_size_t row_bytes);␍␊ |
| 2419 | ␍␊ |
| 2420 | #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)␍␊ |
| 2421 | #define PNG_HISHIFT 10␍␊ |
| 2422 | #define PNG_LOMASK ((png_uint_32)0xffffL)␍␊ |
| 2423 | #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))␍␊ |
| 2424 | void /* PRIVATE */␍␊ |
| 2425 | png_write_find_filter(png_structp png_ptr, png_row_infop row_info)␍␊ |
| 2426 | {␍␊ |
| 2427 | png_bytep best_row;␍␊ |
| 2428 | #ifdef PNG_WRITE_FILTER_SUPPORTED␍␊ |
| 2429 | png_bytep prev_row, row_buf;␍␊ |
| 2430 | png_uint_32 mins, bpp;␍␊ |
| 2431 | png_byte filter_to_do = png_ptr->do_filter;␍␊ |
| 2432 | png_size_t row_bytes = row_info->rowbytes;␍␊ |
| 2433 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 2434 | int num_p_filters = png_ptr->num_prev_filters;␍␊ |
| 2435 | #endif␍␊ |
| 2436 | ␍␊ |
| 2437 | png_debug(1, "in png_write_find_filter");␍␊ |
| 2438 | ␍␊ |
| 2439 | #ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 2440 | if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)␍␊ |
| 2441 | {␍␊ |
| 2442 | /* These will never be selected so we need not test them. */␍␊ |
| 2443 | filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);␍␊ |
| 2444 | }␍␊ |
| 2445 | #endif␍␊ |
| 2446 | ␍␊ |
| 2447 | /* Find out how many bytes offset each pixel is */␍␊ |
| 2448 | bpp = (row_info->pixel_depth + 7) >> 3;␍␊ |
| 2449 | ␍␊ |
| 2450 | prev_row = png_ptr->prev_row;␍␊ |
| 2451 | #endif␍␊ |
| 2452 | best_row = png_ptr->row_buf;␍␊ |
| 2453 | #ifdef PNG_WRITE_FILTER_SUPPORTED␍␊ |
| 2454 | row_buf = best_row;␍␊ |
| 2455 | mins = PNG_MAXSUM;␍␊ |
| 2456 | ␍␊ |
| 2457 | /* The prediction method we use is to find which method provides the␍␊ |
| 2458 | * smallest value when summing the absolute values of the distances␍␊ |
| 2459 | * from zero, using anything >= 128 as negative numbers. This is known␍␊ |
| 2460 | * as the "minimum sum of absolute differences" heuristic. Other␍␊ |
| 2461 | * heuristics are the "weighted minimum sum of absolute differences"␍␊ |
| 2462 | * (experimental and can in theory improve compression), and the "zlib␍␊ |
| 2463 | * predictive" method (not implemented yet), which does test compressions␍␊ |
| 2464 | * of lines using different filter methods, and then chooses the␍␊ |
| 2465 | * (series of) filter(s) that give minimum compressed data size (VERY␍␊ |
| 2466 | * computationally expensive).␍␊ |
| 2467 | *␍␊ |
| 2468 | * GRR 980525: consider also␍␊ |
| 2469 | *␍␊ |
| 2470 | * (1) minimum sum of absolute differences from running average (i.e.,␍␊ |
| 2471 | * keep running sum of non-absolute differences & count of bytes)␍␊ |
| 2472 | * [track dispersion, too? restart average if dispersion too large?]␍␊ |
| 2473 | *␍␊ |
| 2474 | * (1b) minimum sum of absolute differences from sliding average, probably␍␊ |
| 2475 | * with window size <= deflate window (usually 32K)␍␊ |
| 2476 | *␍␊ |
| 2477 | * (2) minimum sum of squared differences from zero or running average␍␊ |
| 2478 | * (i.e., ~ root-mean-square approach)␍␊ |
| 2479 | */␍␊ |
| 2480 | ␍␊ |
| 2481 | ␍␊ |
| 2482 | /* We don't need to test the 'no filter' case if this is the only filter␍␊ |
| 2483 | * that has been chosen, as it doesn't actually do anything to the data.␍␊ |
| 2484 | */␍␊ |
| 2485 | if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE)␍␊ |
| 2486 | {␍␊ |
| 2487 | png_bytep rp;␍␊ |
| 2488 | png_uint_32 sum = 0;␍␊ |
| 2489 | png_size_t i;␍␊ |
| 2490 | int v;␍␊ |
| 2491 | ␍␊ |
| 2492 | for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)␍␊ |
| 2493 | {␍␊ |
| 2494 | v = *rp;␍␊ |
| 2495 | sum += (v < 128) ? v : 256 - v;␍␊ |
| 2496 | }␍␊ |
| 2497 | ␍␊ |
| 2498 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 2499 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)␍␊ |
| 2500 | {␍␊ |
| 2501 | png_uint_32 sumhi, sumlo;␍␊ |
| 2502 | int j;␍␊ |
| 2503 | sumlo = sum & PNG_LOMASK;␍␊ |
| 2504 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */␍␊ |
| 2505 | ␍␊ |
| 2506 | /* Reduce the sum if we match any of the previous rows */␍␊ |
| 2507 | for (j = 0; j < num_p_filters; j++)␍␊ |
| 2508 | {␍␊ |
| 2509 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)␍␊ |
| 2510 | {␍␊ |
| 2511 | sumlo = (sumlo * png_ptr->filter_weights[j]) >>␍␊ |
| 2512 | PNG_WEIGHT_SHIFT;␍␊ |
| 2513 | ␍␊ |
| 2514 | sumhi = (sumhi * png_ptr->filter_weights[j]) >>␍␊ |
| 2515 | PNG_WEIGHT_SHIFT;␍␊ |
| 2516 | }␍␊ |
| 2517 | }␍␊ |
| 2518 | ␍␊ |
| 2519 | /* Factor in the cost of this filter (this is here for completeness,␍␊ |
| 2520 | * but it makes no sense to have a "cost" for the NONE filter, as␍␊ |
| 2521 | * it has the minimum possible computational cost - none).␍␊ |
| 2522 | */␍␊ |
| 2523 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>␍␊ |
| 2524 | PNG_COST_SHIFT;␍␊ |
| 2525 | ␍␊ |
| 2526 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>␍␊ |
| 2527 | PNG_COST_SHIFT;␍␊ |
| 2528 | ␍␊ |
| 2529 | if (sumhi > PNG_HIMASK)␍␊ |
| 2530 | sum = PNG_MAXSUM;␍␊ |
| 2531 | ␍␊ |
| 2532 | else␍␊ |
| 2533 | sum = (sumhi << PNG_HISHIFT) + sumlo;␍␊ |
| 2534 | }␍␊ |
| 2535 | #endif␍␊ |
| 2536 | mins = sum;␍␊ |
| 2537 | }␍␊ |
| 2538 | ␍␊ |
| 2539 | /* Sub filter */␍␊ |
| 2540 | if (filter_to_do == PNG_FILTER_SUB)␍␊ |
| 2541 | /* It's the only filter so no testing is needed */␍␊ |
| 2542 | {␍␊ |
| 2543 | png_bytep rp, lp, dp;␍␊ |
| 2544 | png_size_t i;␍␊ |
| 2545 | ␍␊ |
| 2546 | for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;␍␊ |
| 2547 | i++, rp++, dp++)␍␊ |
| 2548 | {␍␊ |
| 2549 | *dp = *rp;␍␊ |
| 2550 | }␍␊ |
| 2551 | ␍␊ |
| 2552 | for (lp = row_buf + 1; i < row_bytes;␍␊ |
| 2553 | i++, rp++, lp++, dp++)␍␊ |
| 2554 | {␍␊ |
| 2555 | *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);␍␊ |
| 2556 | }␍␊ |
| 2557 | ␍␊ |
| 2558 | best_row = png_ptr->sub_row;␍␊ |
| 2559 | }␍␊ |
| 2560 | ␍␊ |
| 2561 | else if (filter_to_do & PNG_FILTER_SUB)␍␊ |
| 2562 | {␍␊ |
| 2563 | png_bytep rp, dp, lp;␍␊ |
| 2564 | png_uint_32 sum = 0, lmins = mins;␍␊ |
| 2565 | png_size_t i;␍␊ |
| 2566 | int v;␍␊ |
| 2567 | ␍␊ |
| 2568 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 2569 | /* We temporarily increase the "minimum sum" by the factor we␍␊ |
| 2570 | * would reduce the sum of this filter, so that we can do the␍␊ |
| 2571 | * early exit comparison without scaling the sum each time.␍␊ |
| 2572 | */␍␊ |
| 2573 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)␍␊ |
| 2574 | {␍␊ |
| 2575 | int j;␍␊ |
| 2576 | png_uint_32 lmhi, lmlo;␍␊ |
| 2577 | lmlo = lmins & PNG_LOMASK;␍␊ |
| 2578 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;␍␊ |
| 2579 | ␍␊ |
| 2580 | for (j = 0; j < num_p_filters; j++)␍␊ |
| 2581 | {␍␊ |
| 2582 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)␍␊ |
| 2583 | {␍␊ |
| 2584 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>␍␊ |
| 2585 | PNG_WEIGHT_SHIFT;␍␊ |
| 2586 | ␍␊ |
| 2587 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>␍␊ |
| 2588 | PNG_WEIGHT_SHIFT;␍␊ |
| 2589 | }␍␊ |
| 2590 | }␍␊ |
| 2591 | ␍␊ |
| 2592 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>␍␊ |
| 2593 | PNG_COST_SHIFT;␍␊ |
| 2594 | ␍␊ |
| 2595 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>␍␊ |
| 2596 | PNG_COST_SHIFT;␍␊ |
| 2597 | ␍␊ |
| 2598 | if (lmhi > PNG_HIMASK)␍␊ |
| 2599 | lmins = PNG_MAXSUM;␍␊ |
| 2600 | ␍␊ |
| 2601 | else␍␊ |
| 2602 | lmins = (lmhi << PNG_HISHIFT) + lmlo;␍␊ |
| 2603 | }␍␊ |
| 2604 | #endif␍␊ |
| 2605 | ␍␊ |
| 2606 | for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;␍␊ |
| 2607 | i++, rp++, dp++)␍␊ |
| 2608 | {␍␊ |
| 2609 | v = *dp = *rp;␍␊ |
| 2610 | ␍␊ |
| 2611 | sum += (v < 128) ? v : 256 - v;␍␊ |
| 2612 | }␍␊ |
| 2613 | ␍␊ |
| 2614 | for (lp = row_buf + 1; i < row_bytes;␍␊ |
| 2615 | i++, rp++, lp++, dp++)␍␊ |
| 2616 | {␍␊ |
| 2617 | v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);␍␊ |
| 2618 | ␍␊ |
| 2619 | sum += (v < 128) ? v : 256 - v;␍␊ |
| 2620 | ␍␊ |
| 2621 | if (sum > lmins) /* We are already worse, don't continue. */␍␊ |
| 2622 | break;␍␊ |
| 2623 | }␍␊ |
| 2624 | ␍␊ |
| 2625 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 2626 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)␍␊ |
| 2627 | {␍␊ |
| 2628 | int j;␍␊ |
| 2629 | png_uint_32 sumhi, sumlo;␍␊ |
| 2630 | sumlo = sum & PNG_LOMASK;␍␊ |
| 2631 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;␍␊ |
| 2632 | ␍␊ |
| 2633 | for (j = 0; j < num_p_filters; j++)␍␊ |
| 2634 | {␍␊ |
| 2635 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)␍␊ |
| 2636 | {␍␊ |
| 2637 | sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>␍␊ |
| 2638 | PNG_WEIGHT_SHIFT;␍␊ |
| 2639 | ␍␊ |
| 2640 | sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>␍␊ |
| 2641 | PNG_WEIGHT_SHIFT;␍␊ |
| 2642 | }␍␊ |
| 2643 | }␍␊ |
| 2644 | ␍␊ |
| 2645 | sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>␍␊ |
| 2646 | PNG_COST_SHIFT;␍␊ |
| 2647 | ␍␊ |
| 2648 | sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>␍␊ |
| 2649 | PNG_COST_SHIFT;␍␊ |
| 2650 | ␍␊ |
| 2651 | if (sumhi > PNG_HIMASK)␍␊ |
| 2652 | sum = PNG_MAXSUM;␍␊ |
| 2653 | ␍␊ |
| 2654 | else␍␊ |
| 2655 | sum = (sumhi << PNG_HISHIFT) + sumlo;␍␊ |
| 2656 | }␍␊ |
| 2657 | #endif␍␊ |
| 2658 | ␍␊ |
| 2659 | if (sum < mins)␍␊ |
| 2660 | {␍␊ |
| 2661 | mins = sum;␍␊ |
| 2662 | best_row = png_ptr->sub_row;␍␊ |
| 2663 | }␍␊ |
| 2664 | }␍␊ |
| 2665 | ␍␊ |
| 2666 | /* Up filter */␍␊ |
| 2667 | if (filter_to_do == PNG_FILTER_UP)␍␊ |
| 2668 | {␍␊ |
| 2669 | png_bytep rp, dp, pp;␍␊ |
| 2670 | png_size_t i;␍␊ |
| 2671 | ␍␊ |
| 2672 | for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,␍␊ |
| 2673 | pp = prev_row + 1; i < row_bytes;␍␊ |
| 2674 | i++, rp++, pp++, dp++)␍␊ |
| 2675 | {␍␊ |
| 2676 | *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);␍␊ |
| 2677 | }␍␊ |
| 2678 | ␍␊ |
| 2679 | best_row = png_ptr->up_row;␍␊ |
| 2680 | }␍␊ |
| 2681 | ␍␊ |
| 2682 | else if (filter_to_do & PNG_FILTER_UP)␍␊ |
| 2683 | {␍␊ |
| 2684 | png_bytep rp, dp, pp;␍␊ |
| 2685 | png_uint_32 sum = 0, lmins = mins;␍␊ |
| 2686 | png_size_t i;␍␊ |
| 2687 | int v;␍␊ |
| 2688 | ␍␊ |
| 2689 | ␍␊ |
| 2690 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 2691 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)␍␊ |
| 2692 | {␍␊ |
| 2693 | int j;␍␊ |
| 2694 | png_uint_32 lmhi, lmlo;␍␊ |
| 2695 | lmlo = lmins & PNG_LOMASK;␍␊ |
| 2696 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;␍␊ |
| 2697 | ␍␊ |
| 2698 | for (j = 0; j < num_p_filters; j++)␍␊ |
| 2699 | {␍␊ |
| 2700 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)␍␊ |
| 2701 | {␍␊ |
| 2702 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>␍␊ |
| 2703 | PNG_WEIGHT_SHIFT;␍␊ |
| 2704 | ␍␊ |
| 2705 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>␍␊ |
| 2706 | PNG_WEIGHT_SHIFT;␍␊ |
| 2707 | }␍␊ |
| 2708 | }␍␊ |
| 2709 | ␍␊ |
| 2710 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>␍␊ |
| 2711 | PNG_COST_SHIFT;␍␊ |
| 2712 | ␍␊ |
| 2713 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>␍␊ |
| 2714 | PNG_COST_SHIFT;␍␊ |
| 2715 | ␍␊ |
| 2716 | if (lmhi > PNG_HIMASK)␍␊ |
| 2717 | lmins = PNG_MAXSUM;␍␊ |
| 2718 | ␍␊ |
| 2719 | else␍␊ |
| 2720 | lmins = (lmhi << PNG_HISHIFT) + lmlo;␍␊ |
| 2721 | }␍␊ |
| 2722 | #endif␍␊ |
| 2723 | ␍␊ |
| 2724 | for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,␍␊ |
| 2725 | pp = prev_row + 1; i < row_bytes; i++)␍␊ |
| 2726 | {␍␊ |
| 2727 | v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);␍␊ |
| 2728 | ␍␊ |
| 2729 | sum += (v < 128) ? v : 256 - v;␍␊ |
| 2730 | ␍␊ |
| 2731 | if (sum > lmins) /* We are already worse, don't continue. */␍␊ |
| 2732 | break;␍␊ |
| 2733 | }␍␊ |
| 2734 | ␍␊ |
| 2735 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 2736 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)␍␊ |
| 2737 | {␍␊ |
| 2738 | int j;␍␊ |
| 2739 | png_uint_32 sumhi, sumlo;␍␊ |
| 2740 | sumlo = sum & PNG_LOMASK;␍␊ |
| 2741 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;␍␊ |
| 2742 | ␍␊ |
| 2743 | for (j = 0; j < num_p_filters; j++)␍␊ |
| 2744 | {␍␊ |
| 2745 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)␍␊ |
| 2746 | {␍␊ |
| 2747 | sumlo = (sumlo * png_ptr->filter_weights[j]) >>␍␊ |
| 2748 | PNG_WEIGHT_SHIFT;␍␊ |
| 2749 | ␍␊ |
| 2750 | sumhi = (sumhi * png_ptr->filter_weights[j]) >>␍␊ |
| 2751 | PNG_WEIGHT_SHIFT;␍␊ |
| 2752 | }␍␊ |
| 2753 | }␍␊ |
| 2754 | ␍␊ |
| 2755 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>␍␊ |
| 2756 | PNG_COST_SHIFT;␍␊ |
| 2757 | ␍␊ |
| 2758 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>␍␊ |
| 2759 | PNG_COST_SHIFT;␍␊ |
| 2760 | ␍␊ |
| 2761 | if (sumhi > PNG_HIMASK)␍␊ |
| 2762 | sum = PNG_MAXSUM;␍␊ |
| 2763 | ␍␊ |
| 2764 | else␍␊ |
| 2765 | sum = (sumhi << PNG_HISHIFT) + sumlo;␍␊ |
| 2766 | }␍␊ |
| 2767 | #endif␍␊ |
| 2768 | ␍␊ |
| 2769 | if (sum < mins)␍␊ |
| 2770 | {␍␊ |
| 2771 | mins = sum;␍␊ |
| 2772 | best_row = png_ptr->up_row;␍␊ |
| 2773 | }␍␊ |
| 2774 | }␍␊ |
| 2775 | ␍␊ |
| 2776 | /* Avg filter */␍␊ |
| 2777 | if (filter_to_do == PNG_FILTER_AVG)␍␊ |
| 2778 | {␍␊ |
| 2779 | png_bytep rp, dp, pp, lp;␍␊ |
| 2780 | png_uint_32 i;␍␊ |
| 2781 | ␍␊ |
| 2782 | for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,␍␊ |
| 2783 | pp = prev_row + 1; i < bpp; i++)␍␊ |
| 2784 | {␍␊ |
| 2785 | *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);␍␊ |
| 2786 | }␍␊ |
| 2787 | ␍␊ |
| 2788 | for (lp = row_buf + 1; i < row_bytes; i++)␍␊ |
| 2789 | {␍␊ |
| 2790 | *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))␍␊ |
| 2791 | & 0xff);␍␊ |
| 2792 | }␍␊ |
| 2793 | best_row = png_ptr->avg_row;␍␊ |
| 2794 | }␍␊ |
| 2795 | ␍␊ |
| 2796 | else if (filter_to_do & PNG_FILTER_AVG)␍␊ |
| 2797 | {␍␊ |
| 2798 | png_bytep rp, dp, pp, lp;␍␊ |
| 2799 | png_uint_32 sum = 0, lmins = mins;␍␊ |
| 2800 | png_size_t i;␍␊ |
| 2801 | int v;␍␊ |
| 2802 | ␍␊ |
| 2803 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 2804 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)␍␊ |
| 2805 | {␍␊ |
| 2806 | int j;␍␊ |
| 2807 | png_uint_32 lmhi, lmlo;␍␊ |
| 2808 | lmlo = lmins & PNG_LOMASK;␍␊ |
| 2809 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;␍␊ |
| 2810 | ␍␊ |
| 2811 | for (j = 0; j < num_p_filters; j++)␍␊ |
| 2812 | {␍␊ |
| 2813 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)␍␊ |
| 2814 | {␍␊ |
| 2815 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>␍␊ |
| 2816 | PNG_WEIGHT_SHIFT;␍␊ |
| 2817 | ␍␊ |
| 2818 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>␍␊ |
| 2819 | PNG_WEIGHT_SHIFT;␍␊ |
| 2820 | }␍␊ |
| 2821 | }␍␊ |
| 2822 | ␍␊ |
| 2823 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>␍␊ |
| 2824 | PNG_COST_SHIFT;␍␊ |
| 2825 | ␍␊ |
| 2826 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>␍␊ |
| 2827 | PNG_COST_SHIFT;␍␊ |
| 2828 | ␍␊ |
| 2829 | if (lmhi > PNG_HIMASK)␍␊ |
| 2830 | lmins = PNG_MAXSUM;␍␊ |
| 2831 | ␍␊ |
| 2832 | else␍␊ |
| 2833 | lmins = (lmhi << PNG_HISHIFT) + lmlo;␍␊ |
| 2834 | }␍␊ |
| 2835 | #endif␍␊ |
| 2836 | ␍␊ |
| 2837 | for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,␍␊ |
| 2838 | pp = prev_row + 1; i < bpp; i++)␍␊ |
| 2839 | {␍␊ |
| 2840 | v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);␍␊ |
| 2841 | ␍␊ |
| 2842 | sum += (v < 128) ? v : 256 - v;␍␊ |
| 2843 | }␍␊ |
| 2844 | ␍␊ |
| 2845 | for (lp = row_buf + 1; i < row_bytes; i++)␍␊ |
| 2846 | {␍␊ |
| 2847 | v = *dp++ =␍␊ |
| 2848 | (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);␍␊ |
| 2849 | ␍␊ |
| 2850 | sum += (v < 128) ? v : 256 - v;␍␊ |
| 2851 | ␍␊ |
| 2852 | if (sum > lmins) /* We are already worse, don't continue. */␍␊ |
| 2853 | break;␍␊ |
| 2854 | }␍␊ |
| 2855 | ␍␊ |
| 2856 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 2857 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)␍␊ |
| 2858 | {␍␊ |
| 2859 | int j;␍␊ |
| 2860 | png_uint_32 sumhi, sumlo;␍␊ |
| 2861 | sumlo = sum & PNG_LOMASK;␍␊ |
| 2862 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;␍␊ |
| 2863 | ␍␊ |
| 2864 | for (j = 0; j < num_p_filters; j++)␍␊ |
| 2865 | {␍␊ |
| 2866 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)␍␊ |
| 2867 | {␍␊ |
| 2868 | sumlo = (sumlo * png_ptr->filter_weights[j]) >>␍␊ |
| 2869 | PNG_WEIGHT_SHIFT;␍␊ |
| 2870 | ␍␊ |
| 2871 | sumhi = (sumhi * png_ptr->filter_weights[j]) >>␍␊ |
| 2872 | PNG_WEIGHT_SHIFT;␍␊ |
| 2873 | }␍␊ |
| 2874 | }␍␊ |
| 2875 | ␍␊ |
| 2876 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>␍␊ |
| 2877 | PNG_COST_SHIFT;␍␊ |
| 2878 | ␍␊ |
| 2879 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>␍␊ |
| 2880 | PNG_COST_SHIFT;␍␊ |
| 2881 | ␍␊ |
| 2882 | if (sumhi > PNG_HIMASK)␍␊ |
| 2883 | sum = PNG_MAXSUM;␍␊ |
| 2884 | ␍␊ |
| 2885 | else␍␊ |
| 2886 | sum = (sumhi << PNG_HISHIFT) + sumlo;␍␊ |
| 2887 | }␍␊ |
| 2888 | #endif␍␊ |
| 2889 | ␍␊ |
| 2890 | if (sum < mins)␍␊ |
| 2891 | {␍␊ |
| 2892 | mins = sum;␍␊ |
| 2893 | best_row = png_ptr->avg_row;␍␊ |
| 2894 | }␍␊ |
| 2895 | }␍␊ |
| 2896 | ␍␊ |
| 2897 | /* Paeth filter */␍␊ |
| 2898 | if (filter_to_do == PNG_FILTER_PAETH)␍␊ |
| 2899 | {␍␊ |
| 2900 | png_bytep rp, dp, pp, cp, lp;␍␊ |
| 2901 | png_size_t i;␍␊ |
| 2902 | ␍␊ |
| 2903 | for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,␍␊ |
| 2904 | pp = prev_row + 1; i < bpp; i++)␍␊ |
| 2905 | {␍␊ |
| 2906 | *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);␍␊ |
| 2907 | }␍␊ |
| 2908 | ␍␊ |
| 2909 | for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)␍␊ |
| 2910 | {␍␊ |
| 2911 | int a, b, c, pa, pb, pc, p;␍␊ |
| 2912 | ␍␊ |
| 2913 | b = *pp++;␍␊ |
| 2914 | c = *cp++;␍␊ |
| 2915 | a = *lp++;␍␊ |
| 2916 | ␍␊ |
| 2917 | p = b - c;␍␊ |
| 2918 | pc = a - c;␍␊ |
| 2919 | ␍␊ |
| 2920 | #ifdef PNG_USE_ABS␍␊ |
| 2921 | pa = abs(p);␍␊ |
| 2922 | pb = abs(pc);␍␊ |
| 2923 | pc = abs(p + pc);␍␊ |
| 2924 | #else␍␊ |
| 2925 | pa = p < 0 ? -p : p;␍␊ |
| 2926 | pb = pc < 0 ? -pc : pc;␍␊ |
| 2927 | pc = (p + pc) < 0 ? -(p + pc) : p + pc;␍␊ |
| 2928 | #endif␍␊ |
| 2929 | ␍␊ |
| 2930 | p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;␍␊ |
| 2931 | ␍␊ |
| 2932 | *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);␍␊ |
| 2933 | }␍␊ |
| 2934 | best_row = png_ptr->paeth_row;␍␊ |
| 2935 | }␍␊ |
| 2936 | ␍␊ |
| 2937 | else if (filter_to_do & PNG_FILTER_PAETH)␍␊ |
| 2938 | {␍␊ |
| 2939 | png_bytep rp, dp, pp, cp, lp;␍␊ |
| 2940 | png_uint_32 sum = 0, lmins = mins;␍␊ |
| 2941 | png_size_t i;␍␊ |
| 2942 | int v;␍␊ |
| 2943 | ␍␊ |
| 2944 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 2945 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)␍␊ |
| 2946 | {␍␊ |
| 2947 | int j;␍␊ |
| 2948 | png_uint_32 lmhi, lmlo;␍␊ |
| 2949 | lmlo = lmins & PNG_LOMASK;␍␊ |
| 2950 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;␍␊ |
| 2951 | ␍␊ |
| 2952 | for (j = 0; j < num_p_filters; j++)␍␊ |
| 2953 | {␍␊ |
| 2954 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)␍␊ |
| 2955 | {␍␊ |
| 2956 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>␍␊ |
| 2957 | PNG_WEIGHT_SHIFT;␍␊ |
| 2958 | ␍␊ |
| 2959 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>␍␊ |
| 2960 | PNG_WEIGHT_SHIFT;␍␊ |
| 2961 | }␍␊ |
| 2962 | }␍␊ |
| 2963 | ␍␊ |
| 2964 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>␍␊ |
| 2965 | PNG_COST_SHIFT;␍␊ |
| 2966 | ␍␊ |
| 2967 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>␍␊ |
| 2968 | PNG_COST_SHIFT;␍␊ |
| 2969 | ␍␊ |
| 2970 | if (lmhi > PNG_HIMASK)␍␊ |
| 2971 | lmins = PNG_MAXSUM;␍␊ |
| 2972 | ␍␊ |
| 2973 | else␍␊ |
| 2974 | lmins = (lmhi << PNG_HISHIFT) + lmlo;␍␊ |
| 2975 | }␍␊ |
| 2976 | #endif␍␊ |
| 2977 | ␍␊ |
| 2978 | for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,␍␊ |
| 2979 | pp = prev_row + 1; i < bpp; i++)␍␊ |
| 2980 | {␍␊ |
| 2981 | v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);␍␊ |
| 2982 | ␍␊ |
| 2983 | sum += (v < 128) ? v : 256 - v;␍␊ |
| 2984 | }␍␊ |
| 2985 | ␍␊ |
| 2986 | for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)␍␊ |
| 2987 | {␍␊ |
| 2988 | int a, b, c, pa, pb, pc, p;␍␊ |
| 2989 | ␍␊ |
| 2990 | b = *pp++;␍␊ |
| 2991 | c = *cp++;␍␊ |
| 2992 | a = *lp++;␍␊ |
| 2993 | ␍␊ |
| 2994 | #ifndef PNG_SLOW_PAETH␍␊ |
| 2995 | p = b - c;␍␊ |
| 2996 | pc = a - c;␍␊ |
| 2997 | #ifdef PNG_USE_ABS␍␊ |
| 2998 | pa = abs(p);␍␊ |
| 2999 | pb = abs(pc);␍␊ |
| 3000 | pc = abs(p + pc);␍␊ |
| 3001 | #else␍␊ |
| 3002 | pa = p < 0 ? -p : p;␍␊ |
| 3003 | pb = pc < 0 ? -pc : pc;␍␊ |
| 3004 | pc = (p + pc) < 0 ? -(p + pc) : p + pc;␍␊ |
| 3005 | #endif␍␊ |
| 3006 | p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;␍␊ |
| 3007 | #else /* PNG_SLOW_PAETH */␍␊ |
| 3008 | p = a + b - c;␍␊ |
| 3009 | pa = abs(p - a);␍␊ |
| 3010 | pb = abs(p - b);␍␊ |
| 3011 | pc = abs(p - c);␍␊ |
| 3012 | ␍␊ |
| 3013 | if (pa <= pb && pa <= pc)␍␊ |
| 3014 | p = a;␍␊ |
| 3015 | ␍␊ |
| 3016 | else if (pb <= pc)␍␊ |
| 3017 | p = b;␍␊ |
| 3018 | ␍␊ |
| 3019 | else␍␊ |
| 3020 | p = c;␍␊ |
| 3021 | #endif /* PNG_SLOW_PAETH */␍␊ |
| 3022 | ␍␊ |
| 3023 | v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);␍␊ |
| 3024 | ␍␊ |
| 3025 | sum += (v < 128) ? v : 256 - v;␍␊ |
| 3026 | ␍␊ |
| 3027 | if (sum > lmins) /* We are already worse, don't continue. */␍␊ |
| 3028 | break;␍␊ |
| 3029 | }␍␊ |
| 3030 | ␍␊ |
| 3031 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 3032 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)␍␊ |
| 3033 | {␍␊ |
| 3034 | int j;␍␊ |
| 3035 | png_uint_32 sumhi, sumlo;␍␊ |
| 3036 | sumlo = sum & PNG_LOMASK;␍␊ |
| 3037 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;␍␊ |
| 3038 | ␍␊ |
| 3039 | for (j = 0; j < num_p_filters; j++)␍␊ |
| 3040 | {␍␊ |
| 3041 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)␍␊ |
| 3042 | {␍␊ |
| 3043 | sumlo = (sumlo * png_ptr->filter_weights[j]) >>␍␊ |
| 3044 | PNG_WEIGHT_SHIFT;␍␊ |
| 3045 | ␍␊ |
| 3046 | sumhi = (sumhi * png_ptr->filter_weights[j]) >>␍␊ |
| 3047 | PNG_WEIGHT_SHIFT;␍␊ |
| 3048 | }␍␊ |
| 3049 | }␍␊ |
| 3050 | ␍␊ |
| 3051 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>␍␊ |
| 3052 | PNG_COST_SHIFT;␍␊ |
| 3053 | ␍␊ |
| 3054 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>␍␊ |
| 3055 | PNG_COST_SHIFT;␍␊ |
| 3056 | ␍␊ |
| 3057 | if (sumhi > PNG_HIMASK)␍␊ |
| 3058 | sum = PNG_MAXSUM;␍␊ |
| 3059 | ␍␊ |
| 3060 | else␍␊ |
| 3061 | sum = (sumhi << PNG_HISHIFT) + sumlo;␍␊ |
| 3062 | }␍␊ |
| 3063 | #endif␍␊ |
| 3064 | ␍␊ |
| 3065 | if (sum < mins)␍␊ |
| 3066 | {␍␊ |
| 3067 | best_row = png_ptr->paeth_row;␍␊ |
| 3068 | }␍␊ |
| 3069 | }␍␊ |
| 3070 | #endif /* PNG_WRITE_FILTER_SUPPORTED */␍␊ |
| 3071 | ␍␊ |
| 3072 | /* Do the actual writing of the filtered row data from the chosen filter. */␍␊ |
| 3073 | png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);␍␊ |
| 3074 | ␍␊ |
| 3075 | #ifdef PNG_WRITE_FILTER_SUPPORTED␍␊ |
| 3076 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED␍␊ |
| 3077 | /* Save the type of filter we picked this time for future calculations */␍␊ |
| 3078 | if (png_ptr->num_prev_filters > 0)␍␊ |
| 3079 | {␍␊ |
| 3080 | int j;␍␊ |
| 3081 | ␍␊ |
| 3082 | for (j = 1; j < num_p_filters; j++)␍␊ |
| 3083 | {␍␊ |
| 3084 | png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];␍␊ |
| 3085 | }␍␊ |
| 3086 | ␍␊ |
| 3087 | png_ptr->prev_filters[j] = best_row[0];␍␊ |
| 3088 | }␍␊ |
| 3089 | #endif␍␊ |
| 3090 | #endif /* PNG_WRITE_FILTER_SUPPORTED */␍␊ |
| 3091 | }␍␊ |
| 3092 | ␍␊ |
| 3093 | ␍␊ |
| 3094 | /* Do the actual writing of a previously filtered row. */␍␊ |
| 3095 | static void␍␊ |
| 3096 | png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row,␍␊ |
| 3097 | png_size_t avail/*includes filter byte*/)␍␊ |
| 3098 | {␍␊ |
| 3099 | png_debug(1, "in png_write_filtered_row");␍␊ |
| 3100 | ␍␊ |
| 3101 | png_debug1(2, "filter = %d", filtered_row[0]);␍␊ |
| 3102 | /* Set up the zlib input buffer */␍␊ |
| 3103 | ␍␊ |
| 3104 | png_ptr->zstream.next_in = filtered_row;␍␊ |
| 3105 | png_ptr->zstream.avail_in = 0;␍␊ |
| 3106 | /* Repeat until we have compressed all the data */␍␊ |
| 3107 | do␍␊ |
| 3108 | {␍␊ |
| 3109 | int ret; /* Return of zlib */␍␊ |
| 3110 | ␍␊ |
| 3111 | /* Record the number of bytes available - zlib supports at least 65535␍␊ |
| 3112 | * bytes at one step, depending on the size of the zlib type 'uInt', the␍␊ |
| 3113 | * maximum size zlib can write at once is ZLIB_IO_MAX (from pngpriv.h).␍␊ |
| 3114 | * Use this because on 16 bit systems 'rowbytes' can be up to 65536 (i.e.␍␊ |
| 3115 | * one more than 16 bits) and, in this case 'rowbytes+1' can overflow a␍␊ |
| 3116 | * uInt. ZLIB_IO_MAX can be safely reduced to cause zlib to be called␍␊ |
| 3117 | * with smaller chunks of data.␍␊ |
| 3118 | */␍␊ |
| 3119 | if (png_ptr->zstream.avail_in == 0)␍␊ |
| 3120 | {␍␊ |
| 3121 | if (avail > ZLIB_IO_MAX)␍␊ |
| 3122 | {␍␊ |
| 3123 | png_ptr->zstream.avail_in = ZLIB_IO_MAX;␍␊ |
| 3124 | avail -= ZLIB_IO_MAX;␍␊ |
| 3125 | }␍␊ |
| 3126 | ␍␊ |
| 3127 | else␍␊ |
| 3128 | {␍␊ |
| 3129 | /* So this will fit in the available uInt space: */␍␊ |
| 3130 | png_ptr->zstream.avail_in = (uInt)avail;␍␊ |
| 3131 | avail = 0;␍␊ |
| 3132 | }␍␊ |
| 3133 | }␍␊ |
| 3134 | ␍␊ |
| 3135 | /* Compress the data */␍␊ |
| 3136 | ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);␍␊ |
| 3137 | ␍␊ |
| 3138 | /* Check for compression errors */␍␊ |
| 3139 | if (ret != Z_OK)␍␊ |
| 3140 | {␍␊ |
| 3141 | if (png_ptr->zstream.msg != NULL)␍␊ |
| 3142 | png_error(png_ptr, png_ptr->zstream.msg);␍␊ |
| 3143 | ␍␊ |
| 3144 | else␍␊ |
| 3145 | png_error(png_ptr, "zlib error");␍␊ |
| 3146 | }␍␊ |
| 3147 | ␍␊ |
| 3148 | /* See if it is time to write another IDAT */␍␊ |
| 3149 | if (!(png_ptr->zstream.avail_out))␍␊ |
| 3150 | {␍␊ |
| 3151 | /* Write the IDAT and reset the zlib output buffer */␍␊ |
| 3152 | png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);␍␊ |
| 3153 | }␍␊ |
| 3154 | /* Repeat until all data has been compressed */␍␊ |
| 3155 | } while (avail > 0 || png_ptr->zstream.avail_in > 0);␍␊ |
| 3156 | ␍␊ |
| 3157 | /* Swap the current and previous rows */␍␊ |
| 3158 | if (png_ptr->prev_row != NULL)␍␊ |
| 3159 | {␍␊ |
| 3160 | png_bytep tptr;␍␊ |
| 3161 | ␍␊ |
| 3162 | tptr = png_ptr->prev_row;␍␊ |
| 3163 | png_ptr->prev_row = png_ptr->row_buf;␍␊ |
| 3164 | png_ptr->row_buf = tptr;␍␊ |
| 3165 | }␍␊ |
| 3166 | ␍␊ |
| 3167 | /* Finish row - updates counters and flushes zlib if last row */␍␊ |
| 3168 | png_write_finish_row(png_ptr);␍␊ |
| 3169 | ␍␊ |
| 3170 | #ifdef PNG_WRITE_FLUSH_SUPPORTED␍␊ |
| 3171 | png_ptr->flush_rows++;␍␊ |
| 3172 | ␍␊ |
| 3173 | if (png_ptr->flush_dist > 0 &&␍␊ |
| 3174 | png_ptr->flush_rows >= png_ptr->flush_dist)␍␊ |
| 3175 | {␍␊ |
| 3176 | png_write_flush(png_ptr);␍␊ |
| 3177 | }␍␊ |
| 3178 | #endif␍␊ |
| 3179 | }␍␊ |
| 3180 | #endif /* PNG_WRITE_SUPPORTED */␍␊ |
| 3181 | |
