The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 1 | /*--------------------------------------------------------------------------- |
| 2 | |
| 3 | wpng - simple PNG-writing program writepng.c |
| 4 | |
| 5 | --------------------------------------------------------------------------- |
| 6 | |
| 7 | Copyright (c) 1998-2007 Greg Roelofs. All rights reserved. |
| 8 | |
| 9 | This software is provided "as is," without warranty of any kind, |
| 10 | express or implied. In no event shall the author or contributors |
| 11 | be held liable for any damages arising in any way from the use of |
| 12 | this software. |
| 13 | |
| 14 | The contents of this file are DUAL-LICENSED. You may modify and/or |
| 15 | redistribute this software according to the terms of one of the |
| 16 | following two licenses (at your option): |
| 17 | |
| 18 | |
| 19 | LICENSE 1 ("BSD-like with advertising clause"): |
| 20 | |
| 21 | Permission is granted to anyone to use this software for any purpose, |
| 22 | including commercial applications, and to alter it and redistribute |
| 23 | it freely, subject to the following restrictions: |
| 24 | |
| 25 | 1. Redistributions of source code must retain the above copyright |
| 26 | notice, disclaimer, and this list of conditions. |
| 27 | 2. Redistributions in binary form must reproduce the above copyright |
| 28 | notice, disclaimer, and this list of conditions in the documenta- |
| 29 | tion and/or other materials provided with the distribution. |
| 30 | 3. All advertising materials mentioning features or use of this |
| 31 | software must display the following acknowledgment: |
| 32 | |
| 33 | This product includes software developed by Greg Roelofs |
| 34 | and contributors for the book, "PNG: The Definitive Guide," |
| 35 | published by O'Reilly and Associates. |
| 36 | |
| 37 | |
| 38 | LICENSE 2 (GNU GPL v2 or later): |
| 39 | |
| 40 | This program is free software; you can redistribute it and/or modify |
| 41 | it under the terms of the GNU General Public License as published by |
| 42 | the Free Software Foundation; either version 2 of the License, or |
| 43 | (at your option) any later version. |
| 44 | |
| 45 | This program is distributed in the hope that it will be useful, |
| 46 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 47 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 48 | GNU General Public License for more details. |
| 49 | |
| 50 | You should have received a copy of the GNU General Public License |
| 51 | along with this program; if not, write to the Free Software Foundation, |
| 52 | Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 53 | |
| 54 | ---------------------------------------------------------------------------*/ |
| 55 | |
| 56 | |
| 57 | #include <stdlib.h> /* for exit() prototype */ |
| 58 | |
| 59 | #include "png.h" /* libpng header; includes zlib.h and setjmp.h */ |
| 60 | #include "writepng.h" /* typedefs, common macros, public prototypes */ |
| 61 | |
| 62 | |
| 63 | /* local prototype */ |
| 64 | |
| 65 | static void writepng_error_handler(png_structp png_ptr, png_const_charp msg); |
| 66 | |
| 67 | |
| 68 | |
| 69 | void writepng_version_info(void) |
| 70 | { |
| 71 | fprintf(stderr, " Compiled with libpng %s; using libpng %s.\n", |
| 72 | PNG_LIBPNG_VER_STRING, png_libpng_ver); |
| 73 | fprintf(stderr, " Compiled with zlib %s; using zlib %s.\n", |
| 74 | ZLIB_VERSION, zlib_version); |
| 75 | } |
| 76 | |
| 77 | |
| 78 | |
| 79 | |
| 80 | /* returns 0 for success, 2 for libpng problem, 4 for out of memory, 11 for |
| 81 | * unexpected pnmtype; note that outfile might be stdout */ |
| 82 | |
| 83 | int writepng_init(mainprog_info *mainprog_ptr) |
| 84 | { |
| 85 | png_structp png_ptr; /* note: temporary variables! */ |
| 86 | png_infop info_ptr; |
| 87 | int color_type, interlace_type; |
| 88 | |
| 89 | |
| 90 | /* could also replace libpng warning-handler (final NULL), but no need: */ |
| 91 | |
| 92 | png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr, |
| 93 | writepng_error_handler, NULL); |
| 94 | if (!png_ptr) |
| 95 | return 4; /* out of memory */ |
| 96 | |
| 97 | info_ptr = png_create_info_struct(png_ptr); |
| 98 | if (!info_ptr) { |
| 99 | png_destroy_write_struct(&png_ptr, NULL); |
| 100 | return 4; /* out of memory */ |
| 101 | } |
| 102 | |
| 103 | |
| 104 | /* setjmp() must be called in every function that calls a PNG-writing |
| 105 | * libpng function, unless an alternate error handler was installed-- |
| 106 | * but compatible error handlers must either use longjmp() themselves |
| 107 | * (as in this program) or exit immediately, so here we go: */ |
| 108 | |
| 109 | if (setjmp(mainprog_ptr->jmpbuf)) { |
| 110 | png_destroy_write_struct(&png_ptr, &info_ptr); |
| 111 | return 2; |
| 112 | } |
| 113 | |
| 114 | |
| 115 | /* make sure outfile is (re)opened in BINARY mode */ |
| 116 | |
| 117 | png_init_io(png_ptr, mainprog_ptr->outfile); |
| 118 | |
| 119 | |
| 120 | /* set the compression levels--in general, always want to leave filtering |
| 121 | * turned on (except for palette images) and allow all of the filters, |
| 122 | * which is the default; want 32K zlib window, unless entire image buffer |
| 123 | * is 16K or smaller (unknown here)--also the default; usually want max |
| 124 | * compression (NOT the default); and remaining compression flags should |
| 125 | * be left alone */ |
| 126 | |
| 127 | png_set_compression_level(png_ptr, Z_BEST_COMPRESSION); |
| 128 | /* |
| 129 | >> this is default for no filtering; Z_FILTERED is default otherwise: |
| 130 | png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY); |
| 131 | >> these are all defaults: |
| 132 | png_set_compression_mem_level(png_ptr, 8); |
| 133 | png_set_compression_window_bits(png_ptr, 15); |
| 134 | png_set_compression_method(png_ptr, 8); |
| 135 | */ |
| 136 | |
| 137 | |
| 138 | /* set the image parameters appropriately */ |
| 139 | |
| 140 | if (mainprog_ptr->pnmtype == 5) |
| 141 | color_type = PNG_COLOR_TYPE_GRAY; |
| 142 | else if (mainprog_ptr->pnmtype == 6) |
| 143 | color_type = PNG_COLOR_TYPE_RGB; |
| 144 | else if (mainprog_ptr->pnmtype == 8) |
| 145 | color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
| 146 | else { |
| 147 | png_destroy_write_struct(&png_ptr, &info_ptr); |
| 148 | return 11; |
| 149 | } |
| 150 | |
| 151 | interlace_type = mainprog_ptr->interlaced? PNG_INTERLACE_ADAM7 : |
| 152 | PNG_INTERLACE_NONE; |
| 153 | |
| 154 | png_set_IHDR(png_ptr, info_ptr, mainprog_ptr->width, mainprog_ptr->height, |
| 155 | mainprog_ptr->sample_depth, color_type, interlace_type, |
| 156 | PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); |
| 157 | |
| 158 | if (mainprog_ptr->gamma > 0.0) |
| 159 | png_set_gAMA(png_ptr, info_ptr, mainprog_ptr->gamma); |
| 160 | |
| 161 | if (mainprog_ptr->have_bg) { /* we know it's RGBA, not gray+alpha */ |
| 162 | png_color_16 background; |
| 163 | |
| 164 | background.red = mainprog_ptr->bg_red; |
| 165 | background.green = mainprog_ptr->bg_green; |
| 166 | background.blue = mainprog_ptr->bg_blue; |
| 167 | png_set_bKGD(png_ptr, info_ptr, &background); |
| 168 | } |
| 169 | |
| 170 | if (mainprog_ptr->have_time) { |
| 171 | png_time modtime; |
| 172 | |
| 173 | png_convert_from_time_t(&modtime, mainprog_ptr->modtime); |
| 174 | png_set_tIME(png_ptr, info_ptr, &modtime); |
| 175 | } |
| 176 | |
| 177 | if (mainprog_ptr->have_text) { |
| 178 | png_text text[6]; |
| 179 | int num_text = 0; |
| 180 | |
| 181 | if (mainprog_ptr->have_text & TEXT_TITLE) { |
| 182 | text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; |
| 183 | text[num_text].key = "Title"; |
| 184 | text[num_text].text = mainprog_ptr->title; |
| 185 | ++num_text; |
| 186 | } |
| 187 | if (mainprog_ptr->have_text & TEXT_AUTHOR) { |
| 188 | text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; |
| 189 | text[num_text].key = "Author"; |
| 190 | text[num_text].text = mainprog_ptr->author; |
| 191 | ++num_text; |
| 192 | } |
| 193 | if (mainprog_ptr->have_text & TEXT_DESC) { |
| 194 | text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; |
| 195 | text[num_text].key = "Description"; |
| 196 | text[num_text].text = mainprog_ptr->desc; |
| 197 | ++num_text; |
| 198 | } |
| 199 | if (mainprog_ptr->have_text & TEXT_COPY) { |
| 200 | text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; |
| 201 | text[num_text].key = "Copyright"; |
| 202 | text[num_text].text = mainprog_ptr->copyright; |
| 203 | ++num_text; |
| 204 | } |
| 205 | if (mainprog_ptr->have_text & TEXT_EMAIL) { |
| 206 | text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; |
| 207 | text[num_text].key = "E-mail"; |
| 208 | text[num_text].text = mainprog_ptr->email; |
| 209 | ++num_text; |
| 210 | } |
| 211 | if (mainprog_ptr->have_text & TEXT_URL) { |
| 212 | text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; |
| 213 | text[num_text].key = "URL"; |
| 214 | text[num_text].text = mainprog_ptr->url; |
| 215 | ++num_text; |
| 216 | } |
| 217 | png_set_text(png_ptr, info_ptr, text, num_text); |
| 218 | } |
| 219 | |
| 220 | |
| 221 | /* write all chunks up to (but not including) first IDAT */ |
| 222 | |
| 223 | png_write_info(png_ptr, info_ptr); |
| 224 | |
| 225 | |
| 226 | /* if we wanted to write any more text info *after* the image data, we |
| 227 | * would set up text struct(s) here and call png_set_text() again, with |
| 228 | * just the new data; png_set_tIME() could also go here, but it would |
| 229 | * have no effect since we already called it above (only one tIME chunk |
| 230 | * allowed) */ |
| 231 | |
| 232 | |
| 233 | /* set up the transformations: for now, just pack low-bit-depth pixels |
| 234 | * into bytes (one, two or four pixels per byte) */ |
| 235 | |
| 236 | png_set_packing(png_ptr); |
| 237 | /* png_set_shift(png_ptr, &sig_bit); to scale low-bit-depth values */ |
| 238 | |
| 239 | |
| 240 | /* make sure we save our pointers for use in writepng_encode_image() */ |
| 241 | |
| 242 | mainprog_ptr->png_ptr = png_ptr; |
| 243 | mainprog_ptr->info_ptr = info_ptr; |
| 244 | |
| 245 | |
| 246 | /* OK, that's all we need to do for now; return happy */ |
| 247 | |
| 248 | return 0; |
| 249 | } |
| 250 | |
| 251 | |
| 252 | |
| 253 | |
| 254 | |
| 255 | /* returns 0 for success, 2 for libpng (longjmp) problem */ |
| 256 | |
| 257 | int writepng_encode_image(mainprog_info *mainprog_ptr) |
| 258 | { |
| 259 | png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr; |
| 260 | png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr; |
| 261 | |
| 262 | |
| 263 | /* as always, setjmp() must be called in every function that calls a |
| 264 | * PNG-writing libpng function */ |
| 265 | |
| 266 | if (setjmp(mainprog_ptr->jmpbuf)) { |
| 267 | png_destroy_write_struct(&png_ptr, &info_ptr); |
| 268 | mainprog_ptr->png_ptr = NULL; |
| 269 | mainprog_ptr->info_ptr = NULL; |
| 270 | return 2; |
| 271 | } |
| 272 | |
| 273 | |
| 274 | /* and now we just write the whole image; libpng takes care of interlacing |
| 275 | * for us */ |
| 276 | |
| 277 | png_write_image(png_ptr, mainprog_ptr->row_pointers); |
| 278 | |
| 279 | |
| 280 | /* since that's it, we also close out the end of the PNG file now--if we |
| 281 | * had any text or time info to write after the IDATs, second argument |
| 282 | * would be info_ptr, but we optimize slightly by sending NULL pointer: */ |
| 283 | |
| 284 | png_write_end(png_ptr, NULL); |
| 285 | |
| 286 | return 0; |
| 287 | } |
| 288 | |
| 289 | |
| 290 | |
| 291 | |
| 292 | |
| 293 | /* returns 0 if succeeds, 2 if libpng problem */ |
| 294 | |
| 295 | int writepng_encode_row(mainprog_info *mainprog_ptr) /* NON-interlaced only! */ |
| 296 | { |
| 297 | png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr; |
| 298 | png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr; |
| 299 | |
| 300 | |
| 301 | /* as always, setjmp() must be called in every function that calls a |
| 302 | * PNG-writing libpng function */ |
| 303 | |
| 304 | if (setjmp(mainprog_ptr->jmpbuf)) { |
| 305 | png_destroy_write_struct(&png_ptr, &info_ptr); |
| 306 | mainprog_ptr->png_ptr = NULL; |
| 307 | mainprog_ptr->info_ptr = NULL; |
| 308 | return 2; |
| 309 | } |
| 310 | |
| 311 | |
| 312 | /* image_data points at our one row of image data */ |
| 313 | |
| 314 | png_write_row(png_ptr, mainprog_ptr->image_data); |
| 315 | |
| 316 | return 0; |
| 317 | } |
| 318 | |
| 319 | |
| 320 | |
| 321 | |
| 322 | |
| 323 | /* returns 0 if succeeds, 2 if libpng problem */ |
| 324 | |
| 325 | int writepng_encode_finish(mainprog_info *mainprog_ptr) /* NON-interlaced! */ |
| 326 | { |
| 327 | png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr; |
| 328 | png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr; |
| 329 | |
| 330 | |
| 331 | /* as always, setjmp() must be called in every function that calls a |
| 332 | * PNG-writing libpng function */ |
| 333 | |
| 334 | if (setjmp(mainprog_ptr->jmpbuf)) { |
| 335 | png_destroy_write_struct(&png_ptr, &info_ptr); |
| 336 | mainprog_ptr->png_ptr = NULL; |
| 337 | mainprog_ptr->info_ptr = NULL; |
| 338 | return 2; |
| 339 | } |
| 340 | |
| 341 | |
| 342 | /* close out PNG file; if we had any text or time info to write after |
| 343 | * the IDATs, second argument would be info_ptr: */ |
| 344 | |
| 345 | png_write_end(png_ptr, NULL); |
| 346 | |
| 347 | return 0; |
| 348 | } |
| 349 | |
| 350 | |
| 351 | |
| 352 | |
| 353 | |
| 354 | void writepng_cleanup(mainprog_info *mainprog_ptr) |
| 355 | { |
| 356 | png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr; |
| 357 | png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr; |
| 358 | |
| 359 | if (png_ptr && info_ptr) |
| 360 | png_destroy_write_struct(&png_ptr, &info_ptr); |
| 361 | } |
| 362 | |
| 363 | |
| 364 | |
| 365 | |
| 366 | |
| 367 | static void writepng_error_handler(png_structp png_ptr, png_const_charp msg) |
| 368 | { |
| 369 | mainprog_info *mainprog_ptr; |
| 370 | |
| 371 | /* This function, aside from the extra step of retrieving the "error |
| 372 | * pointer" (below) and the fact that it exists within the application |
| 373 | * rather than within libpng, is essentially identical to libpng's |
| 374 | * default error handler. The second point is critical: since both |
| 375 | * setjmp() and longjmp() are called from the same code, they are |
| 376 | * guaranteed to have compatible notions of how big a jmp_buf is, |
| 377 | * regardless of whether _BSD_SOURCE or anything else has (or has not) |
| 378 | * been defined. */ |
| 379 | |
| 380 | fprintf(stderr, "writepng libpng error: %s\n", msg); |
| 381 | fflush(stderr); |
| 382 | |
| 383 | mainprog_ptr = png_get_error_ptr(png_ptr); |
| 384 | if (mainprog_ptr == NULL) { /* we are completely hosed now */ |
| 385 | fprintf(stderr, |
| 386 | "writepng severe error: jmpbuf not recoverable; terminating.\n"); |
| 387 | fflush(stderr); |
| 388 | exit(99); |
| 389 | } |
| 390 | |
| 391 | longjmp(mainprog_ptr->jmpbuf, 1); |
| 392 | } |