istereo2
diff libs/libpng/pngpread.c @ 2:81d35769f546
added the tunnel effect source
author | John Tsiombikas <nuclear@member.fsf.org> |
---|---|
date | Sat, 19 Sep 2015 05:51:51 +0300 |
parents | |
children |
line diff
1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/libs/libpng/pngpread.c Sat Sep 19 05:51:51 2015 +0300 1.3 @@ -0,0 +1,1594 @@ 1.4 + 1.5 +/* pngpread.c - read a png file in push mode 1.6 + * 1.7 + * Last changed in libpng 1.2.32 [September 18, 2008] 1.8 + * For conditions of distribution and use, see copyright notice in png.h 1.9 + * Copyright (c) 1998-2008 Glenn Randers-Pehrson 1.10 + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 1.11 + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 1.12 + */ 1.13 + 1.14 +#define PNG_INTERNAL 1.15 +#include "png.h" 1.16 +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1.17 + 1.18 +/* push model modes */ 1.19 +#define PNG_READ_SIG_MODE 0 1.20 +#define PNG_READ_CHUNK_MODE 1 1.21 +#define PNG_READ_IDAT_MODE 2 1.22 +#define PNG_SKIP_MODE 3 1.23 +#define PNG_READ_tEXt_MODE 4 1.24 +#define PNG_READ_zTXt_MODE 5 1.25 +#define PNG_READ_DONE_MODE 6 1.26 +#define PNG_READ_iTXt_MODE 7 1.27 +#define PNG_ERROR_MODE 8 1.28 + 1.29 +void PNGAPI 1.30 +png_process_data(png_structp png_ptr, png_infop info_ptr, 1.31 + png_bytep buffer, png_size_t buffer_size) 1.32 +{ 1.33 + if (png_ptr == NULL || info_ptr == NULL) return; 1.34 + png_push_restore_buffer(png_ptr, buffer, buffer_size); 1.35 + 1.36 + while (png_ptr->buffer_size) 1.37 + { 1.38 + png_process_some_data(png_ptr, info_ptr); 1.39 + } 1.40 +} 1.41 + 1.42 +/* What we do with the incoming data depends on what we were previously 1.43 + * doing before we ran out of data... 1.44 + */ 1.45 +void /* PRIVATE */ 1.46 +png_process_some_data(png_structp png_ptr, png_infop info_ptr) 1.47 +{ 1.48 + if (png_ptr == NULL) return; 1.49 + switch (png_ptr->process_mode) 1.50 + { 1.51 + case PNG_READ_SIG_MODE: 1.52 + { 1.53 + png_push_read_sig(png_ptr, info_ptr); 1.54 + break; 1.55 + } 1.56 + case PNG_READ_CHUNK_MODE: 1.57 + { 1.58 + png_push_read_chunk(png_ptr, info_ptr); 1.59 + break; 1.60 + } 1.61 + case PNG_READ_IDAT_MODE: 1.62 + { 1.63 + png_push_read_IDAT(png_ptr); 1.64 + break; 1.65 + } 1.66 +#if defined(PNG_READ_tEXt_SUPPORTED) 1.67 + case PNG_READ_tEXt_MODE: 1.68 + { 1.69 + png_push_read_tEXt(png_ptr, info_ptr); 1.70 + break; 1.71 + } 1.72 +#endif 1.73 +#if defined(PNG_READ_zTXt_SUPPORTED) 1.74 + case PNG_READ_zTXt_MODE: 1.75 + { 1.76 + png_push_read_zTXt(png_ptr, info_ptr); 1.77 + break; 1.78 + } 1.79 +#endif 1.80 +#if defined(PNG_READ_iTXt_SUPPORTED) 1.81 + case PNG_READ_iTXt_MODE: 1.82 + { 1.83 + png_push_read_iTXt(png_ptr, info_ptr); 1.84 + break; 1.85 + } 1.86 +#endif 1.87 + case PNG_SKIP_MODE: 1.88 + { 1.89 + png_push_crc_finish(png_ptr); 1.90 + break; 1.91 + } 1.92 + default: 1.93 + { 1.94 + png_ptr->buffer_size = 0; 1.95 + break; 1.96 + } 1.97 + } 1.98 +} 1.99 + 1.100 +/* Read any remaining signature bytes from the stream and compare them with 1.101 + * the correct PNG signature. It is possible that this routine is called 1.102 + * with bytes already read from the signature, either because they have been 1.103 + * checked by the calling application, or because of multiple calls to this 1.104 + * routine. 1.105 + */ 1.106 +void /* PRIVATE */ 1.107 +png_push_read_sig(png_structp png_ptr, png_infop info_ptr) 1.108 +{ 1.109 + png_size_t num_checked = png_ptr->sig_bytes, 1.110 + num_to_check = 8 - num_checked; 1.111 + 1.112 + if (png_ptr->buffer_size < num_to_check) 1.113 + { 1.114 + num_to_check = png_ptr->buffer_size; 1.115 + } 1.116 + 1.117 + png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), 1.118 + num_to_check); 1.119 + png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check); 1.120 + 1.121 + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) 1.122 + { 1.123 + if (num_checked < 4 && 1.124 + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) 1.125 + png_error(png_ptr, "Not a PNG file"); 1.126 + else 1.127 + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); 1.128 + } 1.129 + else 1.130 + { 1.131 + if (png_ptr->sig_bytes >= 8) 1.132 + { 1.133 + png_ptr->process_mode = PNG_READ_CHUNK_MODE; 1.134 + } 1.135 + } 1.136 +} 1.137 + 1.138 +void /* PRIVATE */ 1.139 +png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) 1.140 +{ 1.141 +#ifdef PNG_USE_LOCAL_ARRAYS 1.142 + PNG_CONST PNG_IHDR; 1.143 + PNG_CONST PNG_IDAT; 1.144 + PNG_CONST PNG_IEND; 1.145 + PNG_CONST PNG_PLTE; 1.146 +#if defined(PNG_READ_bKGD_SUPPORTED) 1.147 + PNG_CONST PNG_bKGD; 1.148 +#endif 1.149 +#if defined(PNG_READ_cHRM_SUPPORTED) 1.150 + PNG_CONST PNG_cHRM; 1.151 +#endif 1.152 +#if defined(PNG_READ_gAMA_SUPPORTED) 1.153 + PNG_CONST PNG_gAMA; 1.154 +#endif 1.155 +#if defined(PNG_READ_hIST_SUPPORTED) 1.156 + PNG_CONST PNG_hIST; 1.157 +#endif 1.158 +#if defined(PNG_READ_iCCP_SUPPORTED) 1.159 + PNG_CONST PNG_iCCP; 1.160 +#endif 1.161 +#if defined(PNG_READ_iTXt_SUPPORTED) 1.162 + PNG_CONST PNG_iTXt; 1.163 +#endif 1.164 +#if defined(PNG_READ_oFFs_SUPPORTED) 1.165 + PNG_CONST PNG_oFFs; 1.166 +#endif 1.167 +#if defined(PNG_READ_pCAL_SUPPORTED) 1.168 + PNG_CONST PNG_pCAL; 1.169 +#endif 1.170 +#if defined(PNG_READ_pHYs_SUPPORTED) 1.171 + PNG_CONST PNG_pHYs; 1.172 +#endif 1.173 +#if defined(PNG_READ_sBIT_SUPPORTED) 1.174 + PNG_CONST PNG_sBIT; 1.175 +#endif 1.176 +#if defined(PNG_READ_sCAL_SUPPORTED) 1.177 + PNG_CONST PNG_sCAL; 1.178 +#endif 1.179 +#if defined(PNG_READ_sRGB_SUPPORTED) 1.180 + PNG_CONST PNG_sRGB; 1.181 +#endif 1.182 +#if defined(PNG_READ_sPLT_SUPPORTED) 1.183 + PNG_CONST PNG_sPLT; 1.184 +#endif 1.185 +#if defined(PNG_READ_tEXt_SUPPORTED) 1.186 + PNG_CONST PNG_tEXt; 1.187 +#endif 1.188 +#if defined(PNG_READ_tIME_SUPPORTED) 1.189 + PNG_CONST PNG_tIME; 1.190 +#endif 1.191 +#if defined(PNG_READ_tRNS_SUPPORTED) 1.192 + PNG_CONST PNG_tRNS; 1.193 +#endif 1.194 +#if defined(PNG_READ_zTXt_SUPPORTED) 1.195 + PNG_CONST PNG_zTXt; 1.196 +#endif 1.197 +#endif /* PNG_USE_LOCAL_ARRAYS */ 1.198 + /* First we make sure we have enough data for the 4 byte chunk name 1.199 + * and the 4 byte chunk length before proceeding with decoding the 1.200 + * chunk data. To fully decode each of these chunks, we also make 1.201 + * sure we have enough data in the buffer for the 4 byte CRC at the 1.202 + * end of every chunk (except IDAT, which is handled separately). 1.203 + */ 1.204 + if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) 1.205 + { 1.206 + png_byte chunk_length[4]; 1.207 + 1.208 + if (png_ptr->buffer_size < 8) 1.209 + { 1.210 + png_push_save_buffer(png_ptr); 1.211 + return; 1.212 + } 1.213 + 1.214 + png_push_fill_buffer(png_ptr, chunk_length, 4); 1.215 + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); 1.216 + png_reset_crc(png_ptr); 1.217 + png_crc_read(png_ptr, png_ptr->chunk_name, 4); 1.218 + png_check_chunk_name(png_ptr, png_ptr->chunk_name); 1.219 + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; 1.220 + } 1.221 + 1.222 + if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) 1.223 + if (png_ptr->mode & PNG_AFTER_IDAT) 1.224 + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; 1.225 + 1.226 + if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) 1.227 + { 1.228 + if (png_ptr->push_length != 13) 1.229 + png_error(png_ptr, "Invalid IHDR length"); 1.230 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.231 + { 1.232 + png_push_save_buffer(png_ptr); 1.233 + return; 1.234 + } 1.235 + png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); 1.236 + } 1.237 + else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) 1.238 + { 1.239 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.240 + { 1.241 + png_push_save_buffer(png_ptr); 1.242 + return; 1.243 + } 1.244 + png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); 1.245 + 1.246 + png_ptr->process_mode = PNG_READ_DONE_MODE; 1.247 + png_push_have_end(png_ptr, info_ptr); 1.248 + } 1.249 +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 1.250 + else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name)) 1.251 + { 1.252 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.253 + { 1.254 + png_push_save_buffer(png_ptr); 1.255 + return; 1.256 + } 1.257 + if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) 1.258 + png_ptr->mode |= PNG_HAVE_IDAT; 1.259 + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); 1.260 + if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) 1.261 + png_ptr->mode |= PNG_HAVE_PLTE; 1.262 + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) 1.263 + { 1.264 + if (!(png_ptr->mode & PNG_HAVE_IHDR)) 1.265 + png_error(png_ptr, "Missing IHDR before IDAT"); 1.266 + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && 1.267 + !(png_ptr->mode & PNG_HAVE_PLTE)) 1.268 + png_error(png_ptr, "Missing PLTE before IDAT"); 1.269 + } 1.270 + } 1.271 +#endif 1.272 + else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) 1.273 + { 1.274 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.275 + { 1.276 + png_push_save_buffer(png_ptr); 1.277 + return; 1.278 + } 1.279 + png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); 1.280 + } 1.281 + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) 1.282 + { 1.283 + /* If we reach an IDAT chunk, this means we have read all of the 1.284 + * header chunks, and we can start reading the image (or if this 1.285 + * is called after the image has been read - we have an error). 1.286 + */ 1.287 + if (!(png_ptr->mode & PNG_HAVE_IHDR)) 1.288 + png_error(png_ptr, "Missing IHDR before IDAT"); 1.289 + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && 1.290 + !(png_ptr->mode & PNG_HAVE_PLTE)) 1.291 + png_error(png_ptr, "Missing PLTE before IDAT"); 1.292 + 1.293 + if (png_ptr->mode & PNG_HAVE_IDAT) 1.294 + { 1.295 + if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) 1.296 + if (png_ptr->push_length == 0) 1.297 + return; 1.298 + 1.299 + if (png_ptr->mode & PNG_AFTER_IDAT) 1.300 + png_error(png_ptr, "Too many IDAT's found"); 1.301 + } 1.302 + 1.303 + png_ptr->idat_size = png_ptr->push_length; 1.304 + png_ptr->mode |= PNG_HAVE_IDAT; 1.305 + png_ptr->process_mode = PNG_READ_IDAT_MODE; 1.306 + png_push_have_info(png_ptr, info_ptr); 1.307 + png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; 1.308 + png_ptr->zstream.next_out = png_ptr->row_buf; 1.309 + return; 1.310 + } 1.311 +#if defined(PNG_READ_gAMA_SUPPORTED) 1.312 + else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) 1.313 + { 1.314 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.315 + { 1.316 + png_push_save_buffer(png_ptr); 1.317 + return; 1.318 + } 1.319 + png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); 1.320 + } 1.321 +#endif 1.322 +#if defined(PNG_READ_sBIT_SUPPORTED) 1.323 + else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) 1.324 + { 1.325 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.326 + { 1.327 + png_push_save_buffer(png_ptr); 1.328 + return; 1.329 + } 1.330 + png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); 1.331 + } 1.332 +#endif 1.333 +#if defined(PNG_READ_cHRM_SUPPORTED) 1.334 + else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) 1.335 + { 1.336 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.337 + { 1.338 + png_push_save_buffer(png_ptr); 1.339 + return; 1.340 + } 1.341 + png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); 1.342 + } 1.343 +#endif 1.344 +#if defined(PNG_READ_sRGB_SUPPORTED) 1.345 + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) 1.346 + { 1.347 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.348 + { 1.349 + png_push_save_buffer(png_ptr); 1.350 + return; 1.351 + } 1.352 + png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); 1.353 + } 1.354 +#endif 1.355 +#if defined(PNG_READ_iCCP_SUPPORTED) 1.356 + else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) 1.357 + { 1.358 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.359 + { 1.360 + png_push_save_buffer(png_ptr); 1.361 + return; 1.362 + } 1.363 + png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length); 1.364 + } 1.365 +#endif 1.366 +#if defined(PNG_READ_sPLT_SUPPORTED) 1.367 + else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) 1.368 + { 1.369 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.370 + { 1.371 + png_push_save_buffer(png_ptr); 1.372 + return; 1.373 + } 1.374 + png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length); 1.375 + } 1.376 +#endif 1.377 +#if defined(PNG_READ_tRNS_SUPPORTED) 1.378 + else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) 1.379 + { 1.380 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.381 + { 1.382 + png_push_save_buffer(png_ptr); 1.383 + return; 1.384 + } 1.385 + png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); 1.386 + } 1.387 +#endif 1.388 +#if defined(PNG_READ_bKGD_SUPPORTED) 1.389 + else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) 1.390 + { 1.391 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.392 + { 1.393 + png_push_save_buffer(png_ptr); 1.394 + return; 1.395 + } 1.396 + png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); 1.397 + } 1.398 +#endif 1.399 +#if defined(PNG_READ_hIST_SUPPORTED) 1.400 + else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) 1.401 + { 1.402 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.403 + { 1.404 + png_push_save_buffer(png_ptr); 1.405 + return; 1.406 + } 1.407 + png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); 1.408 + } 1.409 +#endif 1.410 +#if defined(PNG_READ_pHYs_SUPPORTED) 1.411 + else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) 1.412 + { 1.413 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.414 + { 1.415 + png_push_save_buffer(png_ptr); 1.416 + return; 1.417 + } 1.418 + png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); 1.419 + } 1.420 +#endif 1.421 +#if defined(PNG_READ_oFFs_SUPPORTED) 1.422 + else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) 1.423 + { 1.424 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.425 + { 1.426 + png_push_save_buffer(png_ptr); 1.427 + return; 1.428 + } 1.429 + png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); 1.430 + } 1.431 +#endif 1.432 +#if defined(PNG_READ_pCAL_SUPPORTED) 1.433 + else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) 1.434 + { 1.435 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.436 + { 1.437 + png_push_save_buffer(png_ptr); 1.438 + return; 1.439 + } 1.440 + png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); 1.441 + } 1.442 +#endif 1.443 +#if defined(PNG_READ_sCAL_SUPPORTED) 1.444 + else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) 1.445 + { 1.446 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.447 + { 1.448 + png_push_save_buffer(png_ptr); 1.449 + return; 1.450 + } 1.451 + png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length); 1.452 + } 1.453 +#endif 1.454 +#if defined(PNG_READ_tIME_SUPPORTED) 1.455 + else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) 1.456 + { 1.457 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.458 + { 1.459 + png_push_save_buffer(png_ptr); 1.460 + return; 1.461 + } 1.462 + png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); 1.463 + } 1.464 +#endif 1.465 +#if defined(PNG_READ_tEXt_SUPPORTED) 1.466 + else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) 1.467 + { 1.468 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.469 + { 1.470 + png_push_save_buffer(png_ptr); 1.471 + return; 1.472 + } 1.473 + png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); 1.474 + } 1.475 +#endif 1.476 +#if defined(PNG_READ_zTXt_SUPPORTED) 1.477 + else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) 1.478 + { 1.479 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.480 + { 1.481 + png_push_save_buffer(png_ptr); 1.482 + return; 1.483 + } 1.484 + png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); 1.485 + } 1.486 +#endif 1.487 +#if defined(PNG_READ_iTXt_SUPPORTED) 1.488 + else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4)) 1.489 + { 1.490 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.491 + { 1.492 + png_push_save_buffer(png_ptr); 1.493 + return; 1.494 + } 1.495 + png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); 1.496 + } 1.497 +#endif 1.498 + else 1.499 + { 1.500 + if (png_ptr->push_length + 4 > png_ptr->buffer_size) 1.501 + { 1.502 + png_push_save_buffer(png_ptr); 1.503 + return; 1.504 + } 1.505 + png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); 1.506 + } 1.507 + 1.508 + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; 1.509 +} 1.510 + 1.511 +void /* PRIVATE */ 1.512 +png_push_crc_skip(png_structp png_ptr, png_uint_32 skip) 1.513 +{ 1.514 + png_ptr->process_mode = PNG_SKIP_MODE; 1.515 + png_ptr->skip_length = skip; 1.516 +} 1.517 + 1.518 +void /* PRIVATE */ 1.519 +png_push_crc_finish(png_structp png_ptr) 1.520 +{ 1.521 + if (png_ptr->skip_length && png_ptr->save_buffer_size) 1.522 + { 1.523 + png_size_t save_size; 1.524 + 1.525 + if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size) 1.526 + save_size = (png_size_t)png_ptr->skip_length; 1.527 + else 1.528 + save_size = png_ptr->save_buffer_size; 1.529 + 1.530 + png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); 1.531 + 1.532 + png_ptr->skip_length -= save_size; 1.533 + png_ptr->buffer_size -= save_size; 1.534 + png_ptr->save_buffer_size -= save_size; 1.535 + png_ptr->save_buffer_ptr += save_size; 1.536 + } 1.537 + if (png_ptr->skip_length && png_ptr->current_buffer_size) 1.538 + { 1.539 + png_size_t save_size; 1.540 + 1.541 + if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size) 1.542 + save_size = (png_size_t)png_ptr->skip_length; 1.543 + else 1.544 + save_size = png_ptr->current_buffer_size; 1.545 + 1.546 + png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); 1.547 + 1.548 + png_ptr->skip_length -= save_size; 1.549 + png_ptr->buffer_size -= save_size; 1.550 + png_ptr->current_buffer_size -= save_size; 1.551 + png_ptr->current_buffer_ptr += save_size; 1.552 + } 1.553 + if (!png_ptr->skip_length) 1.554 + { 1.555 + if (png_ptr->buffer_size < 4) 1.556 + { 1.557 + png_push_save_buffer(png_ptr); 1.558 + return; 1.559 + } 1.560 + 1.561 + png_crc_finish(png_ptr, 0); 1.562 + png_ptr->process_mode = PNG_READ_CHUNK_MODE; 1.563 + } 1.564 +} 1.565 + 1.566 +void PNGAPI 1.567 +png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) 1.568 +{ 1.569 + png_bytep ptr; 1.570 + 1.571 + if (png_ptr == NULL) return; 1.572 + ptr = buffer; 1.573 + if (png_ptr->save_buffer_size) 1.574 + { 1.575 + png_size_t save_size; 1.576 + 1.577 + if (length < png_ptr->save_buffer_size) 1.578 + save_size = length; 1.579 + else 1.580 + save_size = png_ptr->save_buffer_size; 1.581 + 1.582 + png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size); 1.583 + length -= save_size; 1.584 + ptr += save_size; 1.585 + png_ptr->buffer_size -= save_size; 1.586 + png_ptr->save_buffer_size -= save_size; 1.587 + png_ptr->save_buffer_ptr += save_size; 1.588 + } 1.589 + if (length && png_ptr->current_buffer_size) 1.590 + { 1.591 + png_size_t save_size; 1.592 + 1.593 + if (length < png_ptr->current_buffer_size) 1.594 + save_size = length; 1.595 + else 1.596 + save_size = png_ptr->current_buffer_size; 1.597 + 1.598 + png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size); 1.599 + png_ptr->buffer_size -= save_size; 1.600 + png_ptr->current_buffer_size -= save_size; 1.601 + png_ptr->current_buffer_ptr += save_size; 1.602 + } 1.603 +} 1.604 + 1.605 +void /* PRIVATE */ 1.606 +png_push_save_buffer(png_structp png_ptr) 1.607 +{ 1.608 + if (png_ptr->save_buffer_size) 1.609 + { 1.610 + if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) 1.611 + { 1.612 + png_size_t i, istop; 1.613 + png_bytep sp; 1.614 + png_bytep dp; 1.615 + 1.616 + istop = png_ptr->save_buffer_size; 1.617 + for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; 1.618 + i < istop; i++, sp++, dp++) 1.619 + { 1.620 + *dp = *sp; 1.621 + } 1.622 + } 1.623 + } 1.624 + if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > 1.625 + png_ptr->save_buffer_max) 1.626 + { 1.627 + png_size_t new_max; 1.628 + png_bytep old_buffer; 1.629 + 1.630 + if (png_ptr->save_buffer_size > PNG_SIZE_MAX - 1.631 + (png_ptr->current_buffer_size + 256)) 1.632 + { 1.633 + png_error(png_ptr, "Potential overflow of save_buffer"); 1.634 + } 1.635 + new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; 1.636 + old_buffer = png_ptr->save_buffer; 1.637 + png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr, 1.638 + (png_uint_32)new_max); 1.639 + png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); 1.640 + png_free(png_ptr, old_buffer); 1.641 + png_ptr->save_buffer_max = new_max; 1.642 + } 1.643 + if (png_ptr->current_buffer_size) 1.644 + { 1.645 + png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, 1.646 + png_ptr->current_buffer_ptr, png_ptr->current_buffer_size); 1.647 + png_ptr->save_buffer_size += png_ptr->current_buffer_size; 1.648 + png_ptr->current_buffer_size = 0; 1.649 + } 1.650 + png_ptr->save_buffer_ptr = png_ptr->save_buffer; 1.651 + png_ptr->buffer_size = 0; 1.652 +} 1.653 + 1.654 +void /* PRIVATE */ 1.655 +png_push_restore_buffer(png_structp png_ptr, png_bytep buffer, 1.656 + png_size_t buffer_length) 1.657 +{ 1.658 + png_ptr->current_buffer = buffer; 1.659 + png_ptr->current_buffer_size = buffer_length; 1.660 + png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size; 1.661 + png_ptr->current_buffer_ptr = png_ptr->current_buffer; 1.662 +} 1.663 + 1.664 +void /* PRIVATE */ 1.665 +png_push_read_IDAT(png_structp png_ptr) 1.666 +{ 1.667 +#ifdef PNG_USE_LOCAL_ARRAYS 1.668 + PNG_CONST PNG_IDAT; 1.669 +#endif 1.670 + if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) 1.671 + { 1.672 + png_byte chunk_length[4]; 1.673 + 1.674 + if (png_ptr->buffer_size < 8) 1.675 + { 1.676 + png_push_save_buffer(png_ptr); 1.677 + return; 1.678 + } 1.679 + 1.680 + png_push_fill_buffer(png_ptr, chunk_length, 4); 1.681 + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); 1.682 + png_reset_crc(png_ptr); 1.683 + png_crc_read(png_ptr, png_ptr->chunk_name, 4); 1.684 + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; 1.685 + 1.686 + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) 1.687 + { 1.688 + png_ptr->process_mode = PNG_READ_CHUNK_MODE; 1.689 + if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) 1.690 + png_error(png_ptr, "Not enough compressed data"); 1.691 + return; 1.692 + } 1.693 + 1.694 + png_ptr->idat_size = png_ptr->push_length; 1.695 + } 1.696 + if (png_ptr->idat_size && png_ptr->save_buffer_size) 1.697 + { 1.698 + png_size_t save_size; 1.699 + 1.700 + if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size) 1.701 + { 1.702 + save_size = (png_size_t)png_ptr->idat_size; 1.703 + /* check for overflow */ 1.704 + if ((png_uint_32)save_size != png_ptr->idat_size) 1.705 + png_error(png_ptr, "save_size overflowed in pngpread"); 1.706 + } 1.707 + else 1.708 + save_size = png_ptr->save_buffer_size; 1.709 + 1.710 + png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); 1.711 + if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) 1.712 + png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); 1.713 + png_ptr->idat_size -= save_size; 1.714 + png_ptr->buffer_size -= save_size; 1.715 + png_ptr->save_buffer_size -= save_size; 1.716 + png_ptr->save_buffer_ptr += save_size; 1.717 + } 1.718 + if (png_ptr->idat_size && png_ptr->current_buffer_size) 1.719 + { 1.720 + png_size_t save_size; 1.721 + 1.722 + if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size) 1.723 + { 1.724 + save_size = (png_size_t)png_ptr->idat_size; 1.725 + /* check for overflow */ 1.726 + if ((png_uint_32)save_size != png_ptr->idat_size) 1.727 + png_error(png_ptr, "save_size overflowed in pngpread"); 1.728 + } 1.729 + else 1.730 + save_size = png_ptr->current_buffer_size; 1.731 + 1.732 + png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); 1.733 + if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) 1.734 + png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); 1.735 + 1.736 + png_ptr->idat_size -= save_size; 1.737 + png_ptr->buffer_size -= save_size; 1.738 + png_ptr->current_buffer_size -= save_size; 1.739 + png_ptr->current_buffer_ptr += save_size; 1.740 + } 1.741 + if (!png_ptr->idat_size) 1.742 + { 1.743 + if (png_ptr->buffer_size < 4) 1.744 + { 1.745 + png_push_save_buffer(png_ptr); 1.746 + return; 1.747 + } 1.748 + 1.749 + png_crc_finish(png_ptr, 0); 1.750 + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; 1.751 + png_ptr->mode |= PNG_AFTER_IDAT; 1.752 + } 1.753 +} 1.754 + 1.755 +void /* PRIVATE */ 1.756 +png_process_IDAT_data(png_structp png_ptr, png_bytep buffer, 1.757 + png_size_t buffer_length) 1.758 +{ 1.759 + int ret; 1.760 + 1.761 + if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length) 1.762 + png_error(png_ptr, "Extra compression data"); 1.763 + 1.764 + png_ptr->zstream.next_in = buffer; 1.765 + png_ptr->zstream.avail_in = (uInt)buffer_length; 1.766 + for (;;) 1.767 + { 1.768 + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); 1.769 + if (ret != Z_OK) 1.770 + { 1.771 + if (ret == Z_STREAM_END) 1.772 + { 1.773 + if (png_ptr->zstream.avail_in) 1.774 + png_error(png_ptr, "Extra compressed data"); 1.775 + if (!(png_ptr->zstream.avail_out)) 1.776 + { 1.777 + png_push_process_row(png_ptr); 1.778 + } 1.779 + 1.780 + png_ptr->mode |= PNG_AFTER_IDAT; 1.781 + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; 1.782 + break; 1.783 + } 1.784 + else if (ret == Z_BUF_ERROR) 1.785 + break; 1.786 + else 1.787 + png_error(png_ptr, "Decompression Error"); 1.788 + } 1.789 + if (!(png_ptr->zstream.avail_out)) 1.790 + { 1.791 + if (( 1.792 +#if defined(PNG_READ_INTERLACING_SUPPORTED) 1.793 + png_ptr->interlaced && png_ptr->pass > 6) || 1.794 + (!png_ptr->interlaced && 1.795 +#endif 1.796 + png_ptr->row_number == png_ptr->num_rows)) 1.797 + { 1.798 + if (png_ptr->zstream.avail_in) 1.799 + png_warning(png_ptr, "Too much data in IDAT chunks"); 1.800 + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; 1.801 + break; 1.802 + } 1.803 + png_push_process_row(png_ptr); 1.804 + png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; 1.805 + png_ptr->zstream.next_out = png_ptr->row_buf; 1.806 + } 1.807 + else 1.808 + break; 1.809 + } 1.810 +} 1.811 + 1.812 +void /* PRIVATE */ 1.813 +png_push_process_row(png_structp png_ptr) 1.814 +{ 1.815 + png_ptr->row_info.color_type = png_ptr->color_type; 1.816 + png_ptr->row_info.width = png_ptr->iwidth; 1.817 + png_ptr->row_info.channels = png_ptr->channels; 1.818 + png_ptr->row_info.bit_depth = png_ptr->bit_depth; 1.819 + png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; 1.820 + 1.821 + png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, 1.822 + png_ptr->row_info.width); 1.823 + 1.824 + png_read_filter_row(png_ptr, &(png_ptr->row_info), 1.825 + png_ptr->row_buf + 1, png_ptr->prev_row + 1, 1.826 + (int)(png_ptr->row_buf[0])); 1.827 + 1.828 + png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf, 1.829 + png_ptr->rowbytes + 1); 1.830 + 1.831 + if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) 1.832 + png_do_read_transformations(png_ptr); 1.833 + 1.834 +#if defined(PNG_READ_INTERLACING_SUPPORTED) 1.835 + /* blow up interlaced rows to full size */ 1.836 + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) 1.837 + { 1.838 + if (png_ptr->pass < 6) 1.839 +/* old interface (pre-1.0.9): 1.840 + png_do_read_interlace(&(png_ptr->row_info), 1.841 + png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); 1.842 + */ 1.843 + png_do_read_interlace(png_ptr); 1.844 + 1.845 + switch (png_ptr->pass) 1.846 + { 1.847 + case 0: 1.848 + { 1.849 + int i; 1.850 + for (i = 0; i < 8 && png_ptr->pass == 0; i++) 1.851 + { 1.852 + png_push_have_row(png_ptr, png_ptr->row_buf + 1); 1.853 + png_read_push_finish_row(png_ptr); /* updates png_ptr->pass */ 1.854 + } 1.855 + if (png_ptr->pass == 2) /* pass 1 might be empty */ 1.856 + { 1.857 + for (i = 0; i < 4 && png_ptr->pass == 2; i++) 1.858 + { 1.859 + png_push_have_row(png_ptr, png_bytep_NULL); 1.860 + png_read_push_finish_row(png_ptr); 1.861 + } 1.862 + } 1.863 + if (png_ptr->pass == 4 && png_ptr->height <= 4) 1.864 + { 1.865 + for (i = 0; i < 2 && png_ptr->pass == 4; i++) 1.866 + { 1.867 + png_push_have_row(png_ptr, png_bytep_NULL); 1.868 + png_read_push_finish_row(png_ptr); 1.869 + } 1.870 + } 1.871 + if (png_ptr->pass == 6 && png_ptr->height <= 4) 1.872 + { 1.873 + png_push_have_row(png_ptr, png_bytep_NULL); 1.874 + png_read_push_finish_row(png_ptr); 1.875 + } 1.876 + break; 1.877 + } 1.878 + case 1: 1.879 + { 1.880 + int i; 1.881 + for (i = 0; i < 8 && png_ptr->pass == 1; i++) 1.882 + { 1.883 + png_push_have_row(png_ptr, png_ptr->row_buf + 1); 1.884 + png_read_push_finish_row(png_ptr); 1.885 + } 1.886 + if (png_ptr->pass == 2) /* skip top 4 generated rows */ 1.887 + { 1.888 + for (i = 0; i < 4 && png_ptr->pass == 2; i++) 1.889 + { 1.890 + png_push_have_row(png_ptr, png_bytep_NULL); 1.891 + png_read_push_finish_row(png_ptr); 1.892 + } 1.893 + } 1.894 + break; 1.895 + } 1.896 + case 2: 1.897 + { 1.898 + int i; 1.899 + for (i = 0; i < 4 && png_ptr->pass == 2; i++) 1.900 + { 1.901 + png_push_have_row(png_ptr, png_ptr->row_buf + 1); 1.902 + png_read_push_finish_row(png_ptr); 1.903 + } 1.904 + for (i = 0; i < 4 && png_ptr->pass == 2; i++) 1.905 + { 1.906 + png_push_have_row(png_ptr, png_bytep_NULL); 1.907 + png_read_push_finish_row(png_ptr); 1.908 + } 1.909 + if (png_ptr->pass == 4) /* pass 3 might be empty */ 1.910 + { 1.911 + for (i = 0; i < 2 && png_ptr->pass == 4; i++) 1.912 + { 1.913 + png_push_have_row(png_ptr, png_bytep_NULL); 1.914 + png_read_push_finish_row(png_ptr); 1.915 + } 1.916 + } 1.917 + break; 1.918 + } 1.919 + case 3: 1.920 + { 1.921 + int i; 1.922 + for (i = 0; i < 4 && png_ptr->pass == 3; i++) 1.923 + { 1.924 + png_push_have_row(png_ptr, png_ptr->row_buf + 1); 1.925 + png_read_push_finish_row(png_ptr); 1.926 + } 1.927 + if (png_ptr->pass == 4) /* skip top two generated rows */ 1.928 + { 1.929 + for (i = 0; i < 2 && png_ptr->pass == 4; i++) 1.930 + { 1.931 + png_push_have_row(png_ptr, png_bytep_NULL); 1.932 + png_read_push_finish_row(png_ptr); 1.933 + } 1.934 + } 1.935 + break; 1.936 + } 1.937 + case 4: 1.938 + { 1.939 + int i; 1.940 + for (i = 0; i < 2 && png_ptr->pass == 4; i++) 1.941 + { 1.942 + png_push_have_row(png_ptr, png_ptr->row_buf + 1); 1.943 + png_read_push_finish_row(png_ptr); 1.944 + } 1.945 + for (i = 0; i < 2 && png_ptr->pass == 4; i++) 1.946 + { 1.947 + png_push_have_row(png_ptr, png_bytep_NULL); 1.948 + png_read_push_finish_row(png_ptr); 1.949 + } 1.950 + if (png_ptr->pass == 6) /* pass 5 might be empty */ 1.951 + { 1.952 + png_push_have_row(png_ptr, png_bytep_NULL); 1.953 + png_read_push_finish_row(png_ptr); 1.954 + } 1.955 + break; 1.956 + } 1.957 + case 5: 1.958 + { 1.959 + int i; 1.960 + for (i = 0; i < 2 && png_ptr->pass == 5; i++) 1.961 + { 1.962 + png_push_have_row(png_ptr, png_ptr->row_buf + 1); 1.963 + png_read_push_finish_row(png_ptr); 1.964 + } 1.965 + if (png_ptr->pass == 6) /* skip top generated row */ 1.966 + { 1.967 + png_push_have_row(png_ptr, png_bytep_NULL); 1.968 + png_read_push_finish_row(png_ptr); 1.969 + } 1.970 + break; 1.971 + } 1.972 + case 6: 1.973 + { 1.974 + png_push_have_row(png_ptr, png_ptr->row_buf + 1); 1.975 + png_read_push_finish_row(png_ptr); 1.976 + if (png_ptr->pass != 6) 1.977 + break; 1.978 + png_push_have_row(png_ptr, png_bytep_NULL); 1.979 + png_read_push_finish_row(png_ptr); 1.980 + } 1.981 + } 1.982 + } 1.983 + else 1.984 +#endif 1.985 + { 1.986 + png_push_have_row(png_ptr, png_ptr->row_buf + 1); 1.987 + png_read_push_finish_row(png_ptr); 1.988 + } 1.989 +} 1.990 + 1.991 +void /* PRIVATE */ 1.992 +png_read_push_finish_row(png_structp png_ptr) 1.993 +{ 1.994 +#ifdef PNG_USE_LOCAL_ARRAYS 1.995 + /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ 1.996 + 1.997 + /* start of interlace block */ 1.998 + PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; 1.999 + 1.1000 + /* offset to next interlace block */ 1.1001 + PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; 1.1002 + 1.1003 + /* start of interlace block in the y direction */ 1.1004 + PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; 1.1005 + 1.1006 + /* offset to next interlace block in the y direction */ 1.1007 + PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; 1.1008 + 1.1009 + /* Height of interlace block. This is not currently used - if you need 1.1010 + * it, uncomment it here and in png.h 1.1011 + PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; 1.1012 + */ 1.1013 +#endif 1.1014 + 1.1015 + png_ptr->row_number++; 1.1016 + if (png_ptr->row_number < png_ptr->num_rows) 1.1017 + return; 1.1018 + 1.1019 + if (png_ptr->interlaced) 1.1020 + { 1.1021 + png_ptr->row_number = 0; 1.1022 + png_memset_check(png_ptr, png_ptr->prev_row, 0, 1.1023 + png_ptr->rowbytes + 1); 1.1024 + do 1.1025 + { 1.1026 + png_ptr->pass++; 1.1027 + if ((png_ptr->pass == 1 && png_ptr->width < 5) || 1.1028 + (png_ptr->pass == 3 && png_ptr->width < 3) || 1.1029 + (png_ptr->pass == 5 && png_ptr->width < 2)) 1.1030 + png_ptr->pass++; 1.1031 + 1.1032 + if (png_ptr->pass > 7) 1.1033 + png_ptr->pass--; 1.1034 + if (png_ptr->pass >= 7) 1.1035 + break; 1.1036 + 1.1037 + png_ptr->iwidth = (png_ptr->width + 1.1038 + png_pass_inc[png_ptr->pass] - 1 - 1.1039 + png_pass_start[png_ptr->pass]) / 1.1040 + png_pass_inc[png_ptr->pass]; 1.1041 + 1.1042 + png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, 1.1043 + png_ptr->iwidth) + 1; 1.1044 + 1.1045 + if (png_ptr->transformations & PNG_INTERLACE) 1.1046 + break; 1.1047 + 1.1048 + png_ptr->num_rows = (png_ptr->height + 1.1049 + png_pass_yinc[png_ptr->pass] - 1 - 1.1050 + png_pass_ystart[png_ptr->pass]) / 1.1051 + png_pass_yinc[png_ptr->pass]; 1.1052 + 1.1053 + } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0); 1.1054 + } 1.1055 +} 1.1056 + 1.1057 +#if defined(PNG_READ_tEXt_SUPPORTED) 1.1058 +void /* PRIVATE */ 1.1059 +png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 1.1060 + length) 1.1061 +{ 1.1062 + if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) 1.1063 + { 1.1064 + png_error(png_ptr, "Out of place tEXt"); 1.1065 + info_ptr = info_ptr; /* to quiet some compiler warnings */ 1.1066 + } 1.1067 + 1.1068 +#ifdef PNG_MAX_MALLOC_64K 1.1069 + png_ptr->skip_length = 0; /* This may not be necessary */ 1.1070 + 1.1071 + if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ 1.1072 + { 1.1073 + png_warning(png_ptr, "tEXt chunk too large to fit in memory"); 1.1074 + png_ptr->skip_length = length - (png_uint_32)65535L; 1.1075 + length = (png_uint_32)65535L; 1.1076 + } 1.1077 +#endif 1.1078 + 1.1079 + png_ptr->current_text = (png_charp)png_malloc(png_ptr, 1.1080 + (png_uint_32)(length + 1)); 1.1081 + png_ptr->current_text[length] = '\0'; 1.1082 + png_ptr->current_text_ptr = png_ptr->current_text; 1.1083 + png_ptr->current_text_size = (png_size_t)length; 1.1084 + png_ptr->current_text_left = (png_size_t)length; 1.1085 + png_ptr->process_mode = PNG_READ_tEXt_MODE; 1.1086 +} 1.1087 + 1.1088 +void /* PRIVATE */ 1.1089 +png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr) 1.1090 +{ 1.1091 + if (png_ptr->buffer_size && png_ptr->current_text_left) 1.1092 + { 1.1093 + png_size_t text_size; 1.1094 + 1.1095 + if (png_ptr->buffer_size < png_ptr->current_text_left) 1.1096 + text_size = png_ptr->buffer_size; 1.1097 + else 1.1098 + text_size = png_ptr->current_text_left; 1.1099 + png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); 1.1100 + png_ptr->current_text_left -= text_size; 1.1101 + png_ptr->current_text_ptr += text_size; 1.1102 + } 1.1103 + if (!(png_ptr->current_text_left)) 1.1104 + { 1.1105 + png_textp text_ptr; 1.1106 + png_charp text; 1.1107 + png_charp key; 1.1108 + int ret; 1.1109 + 1.1110 + if (png_ptr->buffer_size < 4) 1.1111 + { 1.1112 + png_push_save_buffer(png_ptr); 1.1113 + return; 1.1114 + } 1.1115 + 1.1116 + png_push_crc_finish(png_ptr); 1.1117 + 1.1118 +#if defined(PNG_MAX_MALLOC_64K) 1.1119 + if (png_ptr->skip_length) 1.1120 + return; 1.1121 +#endif 1.1122 + 1.1123 + key = png_ptr->current_text; 1.1124 + 1.1125 + for (text = key; *text; text++) 1.1126 + /* empty loop */ ; 1.1127 + 1.1128 + if (text < key + png_ptr->current_text_size) 1.1129 + text++; 1.1130 + 1.1131 + text_ptr = (png_textp)png_malloc(png_ptr, 1.1132 + (png_uint_32)png_sizeof(png_text)); 1.1133 + text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; 1.1134 + text_ptr->key = key; 1.1135 +#ifdef PNG_iTXt_SUPPORTED 1.1136 + text_ptr->lang = NULL; 1.1137 + text_ptr->lang_key = NULL; 1.1138 +#endif 1.1139 + text_ptr->text = text; 1.1140 + 1.1141 + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); 1.1142 + 1.1143 + png_free(png_ptr, key); 1.1144 + png_free(png_ptr, text_ptr); 1.1145 + png_ptr->current_text = NULL; 1.1146 + 1.1147 + if (ret) 1.1148 + png_warning(png_ptr, "Insufficient memory to store text chunk."); 1.1149 + } 1.1150 +} 1.1151 +#endif 1.1152 + 1.1153 +#if defined(PNG_READ_zTXt_SUPPORTED) 1.1154 +void /* PRIVATE */ 1.1155 +png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 1.1156 + length) 1.1157 +{ 1.1158 + if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) 1.1159 + { 1.1160 + png_error(png_ptr, "Out of place zTXt"); 1.1161 + info_ptr = info_ptr; /* to quiet some compiler warnings */ 1.1162 + } 1.1163 + 1.1164 +#ifdef PNG_MAX_MALLOC_64K 1.1165 + /* We can't handle zTXt chunks > 64K, since we don't have enough space 1.1166 + * to be able to store the uncompressed data. Actually, the threshold 1.1167 + * is probably around 32K, but it isn't as definite as 64K is. 1.1168 + */ 1.1169 + if (length > (png_uint_32)65535L) 1.1170 + { 1.1171 + png_warning(png_ptr, "zTXt chunk too large to fit in memory"); 1.1172 + png_push_crc_skip(png_ptr, length); 1.1173 + return; 1.1174 + } 1.1175 +#endif 1.1176 + 1.1177 + png_ptr->current_text = (png_charp)png_malloc(png_ptr, 1.1178 + (png_uint_32)(length + 1)); 1.1179 + png_ptr->current_text[length] = '\0'; 1.1180 + png_ptr->current_text_ptr = png_ptr->current_text; 1.1181 + png_ptr->current_text_size = (png_size_t)length; 1.1182 + png_ptr->current_text_left = (png_size_t)length; 1.1183 + png_ptr->process_mode = PNG_READ_zTXt_MODE; 1.1184 +} 1.1185 + 1.1186 +void /* PRIVATE */ 1.1187 +png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr) 1.1188 +{ 1.1189 + if (png_ptr->buffer_size && png_ptr->current_text_left) 1.1190 + { 1.1191 + png_size_t text_size; 1.1192 + 1.1193 + if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left) 1.1194 + text_size = png_ptr->buffer_size; 1.1195 + else 1.1196 + text_size = png_ptr->current_text_left; 1.1197 + png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); 1.1198 + png_ptr->current_text_left -= text_size; 1.1199 + png_ptr->current_text_ptr += text_size; 1.1200 + } 1.1201 + if (!(png_ptr->current_text_left)) 1.1202 + { 1.1203 + png_textp text_ptr; 1.1204 + png_charp text; 1.1205 + png_charp key; 1.1206 + int ret; 1.1207 + png_size_t text_size, key_size; 1.1208 + 1.1209 + if (png_ptr->buffer_size < 4) 1.1210 + { 1.1211 + png_push_save_buffer(png_ptr); 1.1212 + return; 1.1213 + } 1.1214 + 1.1215 + png_push_crc_finish(png_ptr); 1.1216 + 1.1217 + key = png_ptr->current_text; 1.1218 + 1.1219 + for (text = key; *text; text++) 1.1220 + /* empty loop */ ; 1.1221 + 1.1222 + /* zTXt can't have zero text */ 1.1223 + if (text >= key + png_ptr->current_text_size) 1.1224 + { 1.1225 + png_ptr->current_text = NULL; 1.1226 + png_free(png_ptr, key); 1.1227 + return; 1.1228 + } 1.1229 + 1.1230 + text++; 1.1231 + 1.1232 + if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */ 1.1233 + { 1.1234 + png_ptr->current_text = NULL; 1.1235 + png_free(png_ptr, key); 1.1236 + return; 1.1237 + } 1.1238 + 1.1239 + text++; 1.1240 + 1.1241 + png_ptr->zstream.next_in = (png_bytep )text; 1.1242 + png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size - 1.1243 + (text - key)); 1.1244 + png_ptr->zstream.next_out = png_ptr->zbuf; 1.1245 + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; 1.1246 + 1.1247 + key_size = text - key; 1.1248 + text_size = 0; 1.1249 + text = NULL; 1.1250 + ret = Z_STREAM_END; 1.1251 + 1.1252 + while (png_ptr->zstream.avail_in) 1.1253 + { 1.1254 + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); 1.1255 + if (ret != Z_OK && ret != Z_STREAM_END) 1.1256 + { 1.1257 + inflateReset(&png_ptr->zstream); 1.1258 + png_ptr->zstream.avail_in = 0; 1.1259 + png_ptr->current_text = NULL; 1.1260 + png_free(png_ptr, key); 1.1261 + png_free(png_ptr, text); 1.1262 + return; 1.1263 + } 1.1264 + if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END) 1.1265 + { 1.1266 + if (text == NULL) 1.1267 + { 1.1268 + text = (png_charp)png_malloc(png_ptr, 1.1269 + (png_uint_32)(png_ptr->zbuf_size 1.1270 + - png_ptr->zstream.avail_out + key_size + 1)); 1.1271 + png_memcpy(text + key_size, png_ptr->zbuf, 1.1272 + png_ptr->zbuf_size - png_ptr->zstream.avail_out); 1.1273 + png_memcpy(text, key, key_size); 1.1274 + text_size = key_size + png_ptr->zbuf_size - 1.1275 + png_ptr->zstream.avail_out; 1.1276 + *(text + text_size) = '\0'; 1.1277 + } 1.1278 + else 1.1279 + { 1.1280 + png_charp tmp; 1.1281 + 1.1282 + tmp = text; 1.1283 + text = (png_charp)png_malloc(png_ptr, text_size + 1.1284 + (png_uint_32)(png_ptr->zbuf_size 1.1285 + - png_ptr->zstream.avail_out + 1)); 1.1286 + png_memcpy(text, tmp, text_size); 1.1287 + png_free(png_ptr, tmp); 1.1288 + png_memcpy(text + text_size, png_ptr->zbuf, 1.1289 + png_ptr->zbuf_size - png_ptr->zstream.avail_out); 1.1290 + text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; 1.1291 + *(text + text_size) = '\0'; 1.1292 + } 1.1293 + if (ret != Z_STREAM_END) 1.1294 + { 1.1295 + png_ptr->zstream.next_out = png_ptr->zbuf; 1.1296 + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; 1.1297 + } 1.1298 + } 1.1299 + else 1.1300 + { 1.1301 + break; 1.1302 + } 1.1303 + 1.1304 + if (ret == Z_STREAM_END) 1.1305 + break; 1.1306 + } 1.1307 + 1.1308 + inflateReset(&png_ptr->zstream); 1.1309 + png_ptr->zstream.avail_in = 0; 1.1310 + 1.1311 + if (ret != Z_STREAM_END) 1.1312 + { 1.1313 + png_ptr->current_text = NULL; 1.1314 + png_free(png_ptr, key); 1.1315 + png_free(png_ptr, text); 1.1316 + return; 1.1317 + } 1.1318 + 1.1319 + png_ptr->current_text = NULL; 1.1320 + png_free(png_ptr, key); 1.1321 + key = text; 1.1322 + text += key_size; 1.1323 + 1.1324 + text_ptr = (png_textp)png_malloc(png_ptr, 1.1325 + (png_uint_32)png_sizeof(png_text)); 1.1326 + text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt; 1.1327 + text_ptr->key = key; 1.1328 +#ifdef PNG_iTXt_SUPPORTED 1.1329 + text_ptr->lang = NULL; 1.1330 + text_ptr->lang_key = NULL; 1.1331 +#endif 1.1332 + text_ptr->text = text; 1.1333 + 1.1334 + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); 1.1335 + 1.1336 + png_free(png_ptr, key); 1.1337 + png_free(png_ptr, text_ptr); 1.1338 + 1.1339 + if (ret) 1.1340 + png_warning(png_ptr, "Insufficient memory to store text chunk."); 1.1341 + } 1.1342 +} 1.1343 +#endif 1.1344 + 1.1345 +#if defined(PNG_READ_iTXt_SUPPORTED) 1.1346 +void /* PRIVATE */ 1.1347 +png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 1.1348 + length) 1.1349 +{ 1.1350 + if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) 1.1351 + { 1.1352 + png_error(png_ptr, "Out of place iTXt"); 1.1353 + info_ptr = info_ptr; /* to quiet some compiler warnings */ 1.1354 + } 1.1355 + 1.1356 +#ifdef PNG_MAX_MALLOC_64K 1.1357 + png_ptr->skip_length = 0; /* This may not be necessary */ 1.1358 + 1.1359 + if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ 1.1360 + { 1.1361 + png_warning(png_ptr, "iTXt chunk too large to fit in memory"); 1.1362 + png_ptr->skip_length = length - (png_uint_32)65535L; 1.1363 + length = (png_uint_32)65535L; 1.1364 + } 1.1365 +#endif 1.1366 + 1.1367 + png_ptr->current_text = (png_charp)png_malloc(png_ptr, 1.1368 + (png_uint_32)(length + 1)); 1.1369 + png_ptr->current_text[length] = '\0'; 1.1370 + png_ptr->current_text_ptr = png_ptr->current_text; 1.1371 + png_ptr->current_text_size = (png_size_t)length; 1.1372 + png_ptr->current_text_left = (png_size_t)length; 1.1373 + png_ptr->process_mode = PNG_READ_iTXt_MODE; 1.1374 +} 1.1375 + 1.1376 +void /* PRIVATE */ 1.1377 +png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr) 1.1378 +{ 1.1379 + 1.1380 + if (png_ptr->buffer_size && png_ptr->current_text_left) 1.1381 + { 1.1382 + png_size_t text_size; 1.1383 + 1.1384 + if (png_ptr->buffer_size < png_ptr->current_text_left) 1.1385 + text_size = png_ptr->buffer_size; 1.1386 + else 1.1387 + text_size = png_ptr->current_text_left; 1.1388 + png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); 1.1389 + png_ptr->current_text_left -= text_size; 1.1390 + png_ptr->current_text_ptr += text_size; 1.1391 + } 1.1392 + if (!(png_ptr->current_text_left)) 1.1393 + { 1.1394 + png_textp text_ptr; 1.1395 + png_charp key; 1.1396 + int comp_flag; 1.1397 + png_charp lang; 1.1398 + png_charp lang_key; 1.1399 + png_charp text; 1.1400 + int ret; 1.1401 + 1.1402 + if (png_ptr->buffer_size < 4) 1.1403 + { 1.1404 + png_push_save_buffer(png_ptr); 1.1405 + return; 1.1406 + } 1.1407 + 1.1408 + png_push_crc_finish(png_ptr); 1.1409 + 1.1410 +#if defined(PNG_MAX_MALLOC_64K) 1.1411 + if (png_ptr->skip_length) 1.1412 + return; 1.1413 +#endif 1.1414 + 1.1415 + key = png_ptr->current_text; 1.1416 + 1.1417 + for (lang = key; *lang; lang++) 1.1418 + /* empty loop */ ; 1.1419 + 1.1420 + if (lang < key + png_ptr->current_text_size - 3) 1.1421 + lang++; 1.1422 + 1.1423 + comp_flag = *lang++; 1.1424 + lang++; /* skip comp_type, always zero */ 1.1425 + 1.1426 + for (lang_key = lang; *lang_key; lang_key++) 1.1427 + /* empty loop */ ; 1.1428 + lang_key++; /* skip NUL separator */ 1.1429 + 1.1430 + text=lang_key; 1.1431 + if (lang_key < key + png_ptr->current_text_size - 1) 1.1432 + { 1.1433 + for (; *text; text++) 1.1434 + /* empty loop */ ; 1.1435 + } 1.1436 + 1.1437 + if (text < key + png_ptr->current_text_size) 1.1438 + text++; 1.1439 + 1.1440 + text_ptr = (png_textp)png_malloc(png_ptr, 1.1441 + (png_uint_32)png_sizeof(png_text)); 1.1442 + text_ptr->compression = comp_flag + 2; 1.1443 + text_ptr->key = key; 1.1444 + text_ptr->lang = lang; 1.1445 + text_ptr->lang_key = lang_key; 1.1446 + text_ptr->text = text; 1.1447 + text_ptr->text_length = 0; 1.1448 + text_ptr->itxt_length = png_strlen(text); 1.1449 + 1.1450 + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); 1.1451 + 1.1452 + png_ptr->current_text = NULL; 1.1453 + 1.1454 + png_free(png_ptr, text_ptr); 1.1455 + if (ret) 1.1456 + png_warning(png_ptr, "Insufficient memory to store iTXt chunk."); 1.1457 + } 1.1458 +} 1.1459 +#endif 1.1460 + 1.1461 +/* This function is called when we haven't found a handler for this 1.1462 + * chunk. If there isn't a problem with the chunk itself (ie a bad chunk 1.1463 + * name or a critical chunk), the chunk is (currently) silently ignored. 1.1464 + */ 1.1465 +void /* PRIVATE */ 1.1466 +png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 1.1467 + length) 1.1468 +{ 1.1469 + png_uint_32 skip = 0; 1.1470 + 1.1471 + if (!(png_ptr->chunk_name[0] & 0x20)) 1.1472 + { 1.1473 +#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) 1.1474 + if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != 1.1475 + PNG_HANDLE_CHUNK_ALWAYS 1.1476 +#if defined(PNG_READ_USER_CHUNKS_SUPPORTED) 1.1477 + && png_ptr->read_user_chunk_fn == NULL 1.1478 +#endif 1.1479 + ) 1.1480 +#endif 1.1481 + png_chunk_error(png_ptr, "unknown critical chunk"); 1.1482 + 1.1483 + info_ptr = info_ptr; /* to quiet some compiler warnings */ 1.1484 + } 1.1485 + 1.1486 +#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) 1.1487 + if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) 1.1488 + { 1.1489 +#ifdef PNG_MAX_MALLOC_64K 1.1490 + if (length > (png_uint_32)65535L) 1.1491 + { 1.1492 + png_warning(png_ptr, "unknown chunk too large to fit in memory"); 1.1493 + skip = length - (png_uint_32)65535L; 1.1494 + length = (png_uint_32)65535L; 1.1495 + } 1.1496 +#endif 1.1497 + png_memcpy((png_charp)png_ptr->unknown_chunk.name, 1.1498 + (png_charp)png_ptr->chunk_name, 1.1499 + png_sizeof(png_ptr->unknown_chunk.name)); 1.1500 + png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1] 1.1501 + = '\0'; 1.1502 + 1.1503 + png_ptr->unknown_chunk.size = (png_size_t)length; 1.1504 + if (length == 0) 1.1505 + png_ptr->unknown_chunk.data = NULL; 1.1506 + else 1.1507 + { 1.1508 + png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, 1.1509 + (png_uint_32)length); 1.1510 + png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length); 1.1511 + } 1.1512 +#if defined(PNG_READ_USER_CHUNKS_SUPPORTED) 1.1513 + if (png_ptr->read_user_chunk_fn != NULL) 1.1514 + { 1.1515 + /* callback to user unknown chunk handler */ 1.1516 + int ret; 1.1517 + ret = (*(png_ptr->read_user_chunk_fn)) 1.1518 + (png_ptr, &png_ptr->unknown_chunk); 1.1519 + if (ret < 0) 1.1520 + png_chunk_error(png_ptr, "error in user chunk"); 1.1521 + if (ret == 0) 1.1522 + { 1.1523 + if (!(png_ptr->chunk_name[0] & 0x20)) 1.1524 + if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != 1.1525 + PNG_HANDLE_CHUNK_ALWAYS) 1.1526 + png_chunk_error(png_ptr, "unknown critical chunk"); 1.1527 + png_set_unknown_chunks(png_ptr, info_ptr, 1.1528 + &png_ptr->unknown_chunk, 1); 1.1529 + } 1.1530 + } 1.1531 + else 1.1532 +#endif 1.1533 + png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1); 1.1534 + png_free(png_ptr, png_ptr->unknown_chunk.data); 1.1535 + png_ptr->unknown_chunk.data = NULL; 1.1536 + } 1.1537 + else 1.1538 +#endif 1.1539 + skip=length; 1.1540 + png_push_crc_skip(png_ptr, skip); 1.1541 +} 1.1542 + 1.1543 +void /* PRIVATE */ 1.1544 +png_push_have_info(png_structp png_ptr, png_infop info_ptr) 1.1545 +{ 1.1546 + if (png_ptr->info_fn != NULL) 1.1547 + (*(png_ptr->info_fn))(png_ptr, info_ptr); 1.1548 +} 1.1549 + 1.1550 +void /* PRIVATE */ 1.1551 +png_push_have_end(png_structp png_ptr, png_infop info_ptr) 1.1552 +{ 1.1553 + if (png_ptr->end_fn != NULL) 1.1554 + (*(png_ptr->end_fn))(png_ptr, info_ptr); 1.1555 +} 1.1556 + 1.1557 +void /* PRIVATE */ 1.1558 +png_push_have_row(png_structp png_ptr, png_bytep row) 1.1559 +{ 1.1560 + if (png_ptr->row_fn != NULL) 1.1561 + (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number, 1.1562 + (int)png_ptr->pass); 1.1563 +} 1.1564 + 1.1565 +void PNGAPI 1.1566 +png_progressive_combine_row (png_structp png_ptr, 1.1567 + png_bytep old_row, png_bytep new_row) 1.1568 +{ 1.1569 +#ifdef PNG_USE_LOCAL_ARRAYS 1.1570 + PNG_CONST int FARDATA png_pass_dsp_mask[7] = 1.1571 + {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; 1.1572 +#endif 1.1573 + if (png_ptr == NULL) return; 1.1574 + if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */ 1.1575 + png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]); 1.1576 +} 1.1577 + 1.1578 +void PNGAPI 1.1579 +png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr, 1.1580 + png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, 1.1581 + png_progressive_end_ptr end_fn) 1.1582 +{ 1.1583 + if (png_ptr == NULL) return; 1.1584 + png_ptr->info_fn = info_fn; 1.1585 + png_ptr->row_fn = row_fn; 1.1586 + png_ptr->end_fn = end_fn; 1.1587 + 1.1588 + png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); 1.1589 +} 1.1590 + 1.1591 +png_voidp PNGAPI 1.1592 +png_get_progressive_ptr(png_structp png_ptr) 1.1593 +{ 1.1594 + if (png_ptr == NULL) return (NULL); 1.1595 + return png_ptr->io_ptr; 1.1596 +} 1.1597 +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */