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 | |