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Guy Schalnat0d580581995-07-20 02:43:20 -05001
Andreas Dilger47a0c421997-05-16 02:46:07 -05002/* pngwutil.c - utilities to write a PNG file
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06003 *
Glenn Randers-Pehrsond60b8fa2006-04-20 21:31:14 -05004 * Last changed in libpng 1.4.0 April 20, 2006
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06005 * For conditions of distribution and use, see copyright notice in png.h
Glenn Randers-Pehrson9c3ab682006-02-20 22:09:05 -06006 * Copyright (c) 1998-2006 Glenn Randers-Pehrson
Glenn Randers-Pehrsond4366722000-06-04 14:29:29 -05007 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06009 */
Andreas Dilger47a0c421997-05-16 02:46:07 -050010
Guy Schalnat0d580581995-07-20 02:43:20 -050011#include "png.h"
Glenn Randers-Pehrson3097f612001-05-07 14:52:45 -050012#ifdef PNG_WRITE_SUPPORTED
Glenn Randers-Pehrson17218292006-04-20 07:20:46 -050013#include "pngintrn.h"
Guy Schalnat0d580581995-07-20 02:43:20 -050014
Andreas Dilger47a0c421997-05-16 02:46:07 -050015/* Place a 32-bit number into a buffer in PNG byte order. We work
16 * with unsigned numbers for convenience, although one supported
17 * ancillary chunk uses signed (two's complement) numbers.
18 */
Glenn Randers-Pehrson9c3ab682006-02-20 22:09:05 -060019void PNGAPI
Guy Schalnat6d764711995-12-19 03:22:19 -060020png_save_uint_32(png_bytep buf, png_uint_32 i)
Guy Schalnat0d580581995-07-20 02:43:20 -050021{
22 buf[0] = (png_byte)((i >> 24) & 0xff);
23 buf[1] = (png_byte)((i >> 16) & 0xff);
24 buf[2] = (png_byte)((i >> 8) & 0xff);
25 buf[3] = (png_byte)(i & 0xff);
26}
27
Andreas Dilger47a0c421997-05-16 02:46:07 -050028/* The png_save_int_32 function assumes integers are stored in two's
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -060029 * complement format. If this isn't the case, then this routine needs to
30 * be modified to write data in two's complement format.
31 */
Glenn Randers-Pehrson9c3ab682006-02-20 22:09:05 -060032void PNGAPI
Andreas Dilger47a0c421997-05-16 02:46:07 -050033png_save_int_32(png_bytep buf, png_int_32 i)
34{
35 buf[0] = (png_byte)((i >> 24) & 0xff);
36 buf[1] = (png_byte)((i >> 16) & 0xff);
37 buf[2] = (png_byte)((i >> 8) & 0xff);
38 buf[3] = (png_byte)(i & 0xff);
39}
Andreas Dilger47a0c421997-05-16 02:46:07 -050040
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -060041/* Place a 16-bit number into a buffer in PNG byte order.
42 * The parameter is declared unsigned int, not png_uint_16,
43 * just to avoid potential problems on pre-ANSI C compilers.
44 */
Glenn Randers-Pehrson9c3ab682006-02-20 22:09:05 -060045void PNGAPI
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -060046png_save_uint_16(png_bytep buf, unsigned int i)
Guy Schalnat0d580581995-07-20 02:43:20 -050047{
48 buf[0] = (png_byte)((i >> 8) & 0xff);
49 buf[1] = (png_byte)(i & 0xff);
50}
51
Andreas Dilger47a0c421997-05-16 02:46:07 -050052/* Write a PNG chunk all at once. The type is an array of ASCII characters
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -060053 * representing the chunk name. The array must be at least 4 bytes in
54 * length, and does not need to be null terminated. To be safe, pass the
55 * pre-defined chunk names here, and if you need a new one, define it
56 * where the others are defined. The length is the length of the data.
57 * All the data must be present. If that is not possible, use the
58 * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
59 * functions instead.
60 */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -050061void PNGAPI
Andreas Dilger02ad0ef1997-01-17 01:34:35 -060062png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
Andreas Dilger47a0c421997-05-16 02:46:07 -050063 png_bytep data, png_size_t length)
Guy Schalnat0d580581995-07-20 02:43:20 -050064{
Andreas Dilger47a0c421997-05-16 02:46:07 -050065 png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
Andreas Dilger02ad0ef1997-01-17 01:34:35 -060066 png_write_chunk_data(png_ptr, data, length);
67 png_write_chunk_end(png_ptr);
Guy Schalnat0d580581995-07-20 02:43:20 -050068}
69
Andreas Dilger47a0c421997-05-16 02:46:07 -050070/* Write the start of a PNG chunk. The type is the chunk type.
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -060071 * The total_length is the sum of the lengths of all the data you will be
72 * passing in png_write_chunk_data().
73 */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -050074void PNGAPI
Andreas Dilger02ad0ef1997-01-17 01:34:35 -060075png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
76 png_uint_32 length)
Guy Schalnat0d580581995-07-20 02:43:20 -050077{
Andreas Dilger47a0c421997-05-16 02:46:07 -050078 png_byte buf[4];
Glenn Randers-Pehrson4766a242000-07-17 06:17:09 -050079 png_debug2(0, "Writing %s chunk (%lu bytes)\n", chunk_name, length);
Andreas Dilger47a0c421997-05-16 02:46:07 -050080
Guy Schalnat0d580581995-07-20 02:43:20 -050081 /* write the length */
Andreas Dilger47a0c421997-05-16 02:46:07 -050082 png_save_uint_32(buf, length);
83 png_write_data(png_ptr, buf, (png_size_t)4);
84
Guy Schalnat0d580581995-07-20 02:43:20 -050085 /* write the chunk name */
Andreas Dilger47a0c421997-05-16 02:46:07 -050086 png_write_data(png_ptr, chunk_name, (png_size_t)4);
Guy Schalnat0d580581995-07-20 02:43:20 -050087 /* reset the crc and run it over the chunk name */
88 png_reset_crc(png_ptr);
Andreas Dilger47a0c421997-05-16 02:46:07 -050089 png_calculate_crc(png_ptr, chunk_name, (png_size_t)4);
Guy Schalnat0d580581995-07-20 02:43:20 -050090}
91
Andreas Dilger47a0c421997-05-16 02:46:07 -050092/* Write the data of a PNG chunk started with png_write_chunk_start().
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -060093 * Note that multiple calls to this function are allowed, and that the
94 * sum of the lengths from these calls *must* add up to the total_length
95 * given to png_write_chunk_start().
96 */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -050097void PNGAPI
Andreas Dilger47a0c421997-05-16 02:46:07 -050098png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
Guy Schalnat0d580581995-07-20 02:43:20 -050099{
Andreas Dilger47a0c421997-05-16 02:46:07 -0500100 /* write the data, and run the CRC over it */
101 if (data != NULL && length > 0)
Guy Schalnat0d580581995-07-20 02:43:20 -0500102 {
103 png_calculate_crc(png_ptr, data, length);
Guy Schalnat6d764711995-12-19 03:22:19 -0600104 png_write_data(png_ptr, data, length);
Guy Schalnat0d580581995-07-20 02:43:20 -0500105 }
106}
107
Andreas Dilger47a0c421997-05-16 02:46:07 -0500108/* Finish a chunk started with png_write_chunk_start(). */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500109void PNGAPI
Guy Schalnat6d764711995-12-19 03:22:19 -0600110png_write_chunk_end(png_structp png_ptr)
Guy Schalnat0d580581995-07-20 02:43:20 -0500111{
Andreas Dilger47a0c421997-05-16 02:46:07 -0500112 png_byte buf[4];
113
Guy Schalnat0d580581995-07-20 02:43:20 -0500114 /* write the crc */
Andreas Dilger47a0c421997-05-16 02:46:07 -0500115 png_save_uint_32(buf, png_ptr->crc);
Andreas Dilger47a0c421997-05-16 02:46:07 -0500116
117 png_write_data(png_ptr, buf, (png_size_t)4);
Guy Schalnat0d580581995-07-20 02:43:20 -0500118}
119
Andreas Dilger02ad0ef1997-01-17 01:34:35 -0600120/* Simple function to write the signature. If we have already written
121 * the magic bytes of the signature, or more likely, the PNG stream is
122 * being embedded into another stream and doesn't need its own signature,
123 * we should call png_set_sig_bytes() to tell libpng how many of the
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -0600124 * bytes have already been written.
125 */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500126void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -0600127png_write_sig(png_structp png_ptr)
Guy Schalnat0d580581995-07-20 02:43:20 -0500128{
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -0600129 png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
Andreas Dilger02ad0ef1997-01-17 01:34:35 -0600130 /* write the rest of the 8 byte signature */
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -0600131 png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
Andreas Dilger47a0c421997-05-16 02:46:07 -0500132 (png_size_t)8 - png_ptr->sig_bytes);
Glenn Randers-Pehrson408b4212000-12-18 09:33:57 -0600133 if(png_ptr->sig_bytes < 3)
134 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
Guy Schalnat0d580581995-07-20 02:43:20 -0500135}
136
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600137#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600138/*
139 * This pair of functions encapsulates the operation of (a) compressing a
140 * text string, and (b) issuing it later as a series of chunk data writes.
141 * The compression_state structure is shared context for these functions
142 * set up by the caller in order to make the whole mess thread-safe.
143 */
144
145typedef struct
146{
147 char *input; /* the uncompressed input data */
148 int input_len; /* its length */
149 int num_output_ptr; /* number of output pointers used */
150 int max_output_ptr; /* size of output_ptr */
151 png_charpp output_ptr; /* array of pointers to output */
152} compression_state;
153
154/* compress given text into storage in the png_ptr structure */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500155static int /* PRIVATE */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600156png_text_compress(png_structp png_ptr,
157 png_charp text, png_size_t text_len, int compression,
158 compression_state *comp)
159{
160 int ret;
161
Glenn Randers-Pehrson9c3ab682006-02-20 22:09:05 -0600162 comp->num_output_ptr = 0;
163 comp->max_output_ptr = 0;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600164 comp->output_ptr = NULL;
165 comp->input = NULL;
Glenn Randers-Pehrson9c3ab682006-02-20 22:09:05 -0600166 comp->input_len = 0;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600167
168 /* we may just want to pass the text right through */
169 if (compression == PNG_TEXT_COMPRESSION_NONE)
170 {
171 comp->input = text;
172 comp->input_len = text_len;
Glenn Randers-Pehrson6942d532000-05-01 09:31:54 -0500173 return((int)text_len);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600174 }
175
176 if (compression >= PNG_TEXT_COMPRESSION_LAST)
177 {
Glenn Randers-Pehrson17218292006-04-20 07:20:46 -0500178#ifndef PNG_NO_STDIO
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600179 char msg[50];
Glenn Randers-Pehrson17218292006-04-20 07:20:46 -0500180 png_sprintf(msg, "Unknown compression type %d", compression);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600181 png_warning(png_ptr, msg);
182#else
183 png_warning(png_ptr, "Unknown compression type");
184#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600185 }
186
187 /* We can't write the chunk until we find out how much data we have,
188 * which means we need to run the compressor first and save the
189 * output. This shouldn't be a problem, as the vast majority of
190 * comments should be reasonable, but we will set up an array of
191 * malloc'd pointers to be sure.
192 *
193 * If we knew the application was well behaved, we could simplify this
194 * greatly by assuming we can always malloc an output buffer large
195 * enough to hold the compressed text ((1001 * text_len / 1000) + 12)
196 * and malloc this directly. The only time this would be a bad idea is
197 * if we can't malloc more than 64K and we have 64K of random input
198 * data, or if the input string is incredibly large (although this
199 * wouldn't cause a failure, just a slowdown due to swapping).
200 */
201
202 /* set up the compression buffers */
203 png_ptr->zstream.avail_in = (uInt)text_len;
204 png_ptr->zstream.next_in = (Bytef *)text;
205 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
206 png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;
207
208 /* this is the same compression loop as in png_write_row() */
209 do
210 {
211 /* compress the data */
212 ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
213 if (ret != Z_OK)
214 {
215 /* error */
216 if (png_ptr->zstream.msg != NULL)
217 png_error(png_ptr, png_ptr->zstream.msg);
218 else
219 png_error(png_ptr, "zlib error");
220 }
221 /* check to see if we need more room */
Glenn Randers-Pehrson16e11662004-11-01 14:13:40 -0600222 if (!(png_ptr->zstream.avail_out))
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600223 {
224 /* make sure the output array has room */
225 if (comp->num_output_ptr >= comp->max_output_ptr)
226 {
227 int old_max;
228
229 old_max = comp->max_output_ptr;
230 comp->max_output_ptr = comp->num_output_ptr + 4;
231 if (comp->output_ptr != NULL)
232 {
233 png_charpp old_ptr;
234
235 old_ptr = comp->output_ptr;
236 comp->output_ptr = (png_charpp)png_malloc(png_ptr,
Glenn Randers-Pehrson5fea36f2004-07-28 08:20:44 -0500237 (png_uint_32)(comp->max_output_ptr *
238 png_sizeof (png_charpp)));
Glenn Randers-Pehrson3097f612001-05-07 14:52:45 -0500239 png_memcpy(comp->output_ptr, old_ptr, old_max
Glenn Randers-Pehrson5fea36f2004-07-28 08:20:44 -0500240 * png_sizeof (png_charp));
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600241 png_free(png_ptr, old_ptr);
242 }
243 else
244 comp->output_ptr = (png_charpp)png_malloc(png_ptr,
Glenn Randers-Pehrson5fea36f2004-07-28 08:20:44 -0500245 (png_uint_32)(comp->max_output_ptr *
246 png_sizeof (png_charp)));
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600247 }
248
249 /* save the data */
250 comp->output_ptr[comp->num_output_ptr] = (png_charp)png_malloc(png_ptr,
251 (png_uint_32)png_ptr->zbuf_size);
Glenn Randers-Pehrson82ae3832001-04-20 10:32:10 -0500252 png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
253 png_ptr->zbuf_size);
254 comp->num_output_ptr++;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600255
256 /* and reset the buffer */
257 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
258 png_ptr->zstream.next_out = png_ptr->zbuf;
259 }
260 /* continue until we don't have any more to compress */
261 } while (png_ptr->zstream.avail_in);
262
263 /* finish the compression */
264 do
265 {
266 /* tell zlib we are finished */
267 ret = deflate(&png_ptr->zstream, Z_FINISH);
Glenn Randers-Pehrson104622b2000-05-29 08:58:03 -0500268
269 if (ret == Z_OK)
270 {
271 /* check to see if we need more room */
272 if (!(png_ptr->zstream.avail_out))
273 {
274 /* check to make sure our output array has room */
275 if (comp->num_output_ptr >= comp->max_output_ptr)
276 {
277 int old_max;
278
279 old_max = comp->max_output_ptr;
280 comp->max_output_ptr = comp->num_output_ptr + 4;
281 if (comp->output_ptr != NULL)
282 {
283 png_charpp old_ptr;
284
285 old_ptr = comp->output_ptr;
286 /* This could be optimized to realloc() */
287 comp->output_ptr = (png_charpp)png_malloc(png_ptr,
Glenn Randers-Pehrson5fea36f2004-07-28 08:20:44 -0500288 (png_uint_32)(comp->max_output_ptr *
289 png_sizeof (png_charpp)));
Glenn Randers-Pehrson82ae3832001-04-20 10:32:10 -0500290 png_memcpy(comp->output_ptr, old_ptr,
Glenn Randers-Pehrson5fea36f2004-07-28 08:20:44 -0500291 old_max * png_sizeof (png_charp));
Glenn Randers-Pehrson104622b2000-05-29 08:58:03 -0500292 png_free(png_ptr, old_ptr);
293 }
294 else
295 comp->output_ptr = (png_charpp)png_malloc(png_ptr,
Glenn Randers-Pehrson5fea36f2004-07-28 08:20:44 -0500296 (png_uint_32)(comp->max_output_ptr *
297 png_sizeof (png_charp)));
Glenn Randers-Pehrson104622b2000-05-29 08:58:03 -0500298 }
299
300 /* save off the data */
301 comp->output_ptr[comp->num_output_ptr] =
302 (png_charp)png_malloc(png_ptr, (png_uint_32)png_ptr->zbuf_size);
Glenn Randers-Pehrson82ae3832001-04-20 10:32:10 -0500303 png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
304 png_ptr->zbuf_size);
305 comp->num_output_ptr++;
Glenn Randers-Pehrson104622b2000-05-29 08:58:03 -0500306
307 /* and reset the buffer pointers */
308 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
309 png_ptr->zstream.next_out = png_ptr->zbuf;
310 }
311 }
312 else if (ret != Z_STREAM_END)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600313 {
314 /* we got an error */
315 if (png_ptr->zstream.msg != NULL)
316 png_error(png_ptr, png_ptr->zstream.msg);
317 else
318 png_error(png_ptr, "zlib error");
319 }
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600320 } while (ret != Z_STREAM_END);
321
322 /* text length is number of buffers plus last buffer */
323 text_len = png_ptr->zbuf_size * comp->num_output_ptr;
324 if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
325 text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
326
Glenn Randers-Pehrson6942d532000-05-01 09:31:54 -0500327 return((int)text_len);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600328}
329
330/* ship the compressed text out via chunk writes */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500331static void /* PRIVATE */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600332png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
333{
334 int i;
335
336 /* handle the no-compression case */
337 if (comp->input)
338 {
Glenn Randers-Pehrsonb1828932001-06-23 08:03:17 -0500339 png_write_chunk_data(png_ptr, (png_bytep)comp->input,
340 (png_size_t)comp->input_len);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600341 return;
342 }
343
344 /* write saved output buffers, if any */
345 for (i = 0; i < comp->num_output_ptr; i++)
346 {
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600347 png_write_chunk_data(png_ptr,(png_bytep)comp->output_ptr[i],
348 png_ptr->zbuf_size);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600349 png_free(png_ptr, comp->output_ptr[i]);
Glenn Randers-Pehrson4766a242000-07-17 06:17:09 -0500350 comp->output_ptr[i]=NULL;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600351 }
352 if (comp->max_output_ptr != 0)
353 png_free(png_ptr, comp->output_ptr);
Glenn Randers-Pehrson4766a242000-07-17 06:17:09 -0500354 comp->output_ptr=NULL;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600355 /* write anything left in zbuf */
356 if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
357 png_write_chunk_data(png_ptr, png_ptr->zbuf,
358 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
359
Glenn Randers-Pehrson878b31e2004-11-12 22:04:56 -0600360 /* reset zlib for another zTXt/iTXt or image data */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600361 deflateReset(&png_ptr->zstream);
Glenn Randers-Pehrson878b31e2004-11-12 22:04:56 -0600362 png_ptr->zstream.data_type = Z_BINARY;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600363}
364#endif
365
Guy Schalnat0d580581995-07-20 02:43:20 -0500366/* Write the IHDR chunk, and update the png_struct with the necessary
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -0600367 * information. Note that the rest of this code depends upon this
368 * information being correct.
369 */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500370void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -0600371png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
Guy Schalnat0d580581995-07-20 02:43:20 -0500372 int bit_depth, int color_type, int compression_type, int filter_type,
373 int interlace_type)
374{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -0600375#ifdef PNG_USE_LOCAL_ARRAYS
376 PNG_IHDR;
377#endif
Guy Schalnat0d580581995-07-20 02:43:20 -0500378 png_byte buf[13]; /* buffer to store the IHDR info */
379
Andreas Dilger47a0c421997-05-16 02:46:07 -0500380 png_debug(1, "in png_write_IHDR\n");
Guy Schalnate5a37791996-06-05 15:50:50 -0500381 /* Check that we have valid input data from the application info */
382 switch (color_type)
383 {
Andreas Dilger47a0c421997-05-16 02:46:07 -0500384 case PNG_COLOR_TYPE_GRAY:
Guy Schalnate5a37791996-06-05 15:50:50 -0500385 switch (bit_depth)
386 {
387 case 1:
388 case 2:
389 case 4:
390 case 8:
391 case 16: png_ptr->channels = 1; break;
Andreas Dilger47a0c421997-05-16 02:46:07 -0500392 default: png_error(png_ptr,"Invalid bit depth for grayscale image");
Guy Schalnate5a37791996-06-05 15:50:50 -0500393 }
394 break;
Andreas Dilger47a0c421997-05-16 02:46:07 -0500395 case PNG_COLOR_TYPE_RGB:
Guy Schalnate5a37791996-06-05 15:50:50 -0500396 if (bit_depth != 8 && bit_depth != 16)
397 png_error(png_ptr, "Invalid bit depth for RGB image");
398 png_ptr->channels = 3;
399 break;
Andreas Dilger47a0c421997-05-16 02:46:07 -0500400 case PNG_COLOR_TYPE_PALETTE:
Guy Schalnate5a37791996-06-05 15:50:50 -0500401 switch (bit_depth)
402 {
403 case 1:
404 case 2:
405 case 4:
406 case 8: png_ptr->channels = 1; break;
407 default: png_error(png_ptr, "Invalid bit depth for paletted image");
408 }
409 break;
Andreas Dilger47a0c421997-05-16 02:46:07 -0500410 case PNG_COLOR_TYPE_GRAY_ALPHA:
Guy Schalnate5a37791996-06-05 15:50:50 -0500411 if (bit_depth != 8 && bit_depth != 16)
412 png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
413 png_ptr->channels = 2;
414 break;
Andreas Dilger47a0c421997-05-16 02:46:07 -0500415 case PNG_COLOR_TYPE_RGB_ALPHA:
Guy Schalnate5a37791996-06-05 15:50:50 -0500416 if (bit_depth != 8 && bit_depth != 16)
417 png_error(png_ptr, "Invalid bit depth for RGBA image");
418 png_ptr->channels = 4;
419 break;
420 default:
421 png_error(png_ptr, "Invalid image color type specified");
422 }
423
Andreas Dilger47a0c421997-05-16 02:46:07 -0500424 if (compression_type != PNG_COMPRESSION_TYPE_BASE)
Guy Schalnate5a37791996-06-05 15:50:50 -0500425 {
426 png_warning(png_ptr, "Invalid compression type specified");
Andreas Dilger47a0c421997-05-16 02:46:07 -0500427 compression_type = PNG_COMPRESSION_TYPE_BASE;
Guy Schalnate5a37791996-06-05 15:50:50 -0500428 }
429
Glenn Randers-Pehrson408b4212000-12-18 09:33:57 -0600430 /* Write filter_method 64 (intrapixel differencing) only if
431 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
432 * 2. Libpng did not write a PNG signature (this filter_method is only
433 * used in PNG datastreams that are embedded in MNG datastreams) and
434 * 3. The application called png_permit_mng_features with a mask that
435 * included PNG_FLAG_MNG_FILTER_64 and
436 * 4. The filter_method is 64 and
437 * 5. The color_type is RGB or RGBA
438 */
Glenn Randers-Pehrson2ad31ae2000-12-15 08:54:42 -0600439 if (
440#if defined(PNG_MNG_FEATURES_SUPPORTED)
441 !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
Glenn Randers-Pehrson408b4212000-12-18 09:33:57 -0600442 ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
Glenn Randers-Pehrson3097f612001-05-07 14:52:45 -0500443 (color_type == PNG_COLOR_TYPE_RGB ||
Glenn Randers-Pehrson408b4212000-12-18 09:33:57 -0600444 color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
Glenn Randers-Pehrson2ad31ae2000-12-15 08:54:42 -0600445 (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
446#endif
447 filter_type != PNG_FILTER_TYPE_BASE)
Guy Schalnate5a37791996-06-05 15:50:50 -0500448 {
449 png_warning(png_ptr, "Invalid filter type specified");
Andreas Dilger47a0c421997-05-16 02:46:07 -0500450 filter_type = PNG_FILTER_TYPE_BASE;
Guy Schalnate5a37791996-06-05 15:50:50 -0500451 }
452
Glenn Randers-Pehrson46f61e21998-01-30 21:45:12 -0600453#ifdef PNG_WRITE_INTERLACING_SUPPORTED
Andreas Dilger47a0c421997-05-16 02:46:07 -0500454 if (interlace_type != PNG_INTERLACE_NONE &&
455 interlace_type != PNG_INTERLACE_ADAM7)
Guy Schalnate5a37791996-06-05 15:50:50 -0500456 {
457 png_warning(png_ptr, "Invalid interlace type specified");
Andreas Dilger47a0c421997-05-16 02:46:07 -0500458 interlace_type = PNG_INTERLACE_ADAM7;
Guy Schalnate5a37791996-06-05 15:50:50 -0500459 }
Glenn Randers-Pehrson46f61e21998-01-30 21:45:12 -0600460#else
461 interlace_type=PNG_INTERLACE_NONE;
462#endif
Guy Schalnate5a37791996-06-05 15:50:50 -0500463
464 /* save off the relevent information */
465 png_ptr->bit_depth = (png_byte)bit_depth;
466 png_ptr->color_type = (png_byte)color_type;
467 png_ptr->interlaced = (png_byte)interlace_type;
Glenn Randers-Pehrson8b6a8892001-05-18 04:54:50 -0500468#if defined(PNG_MNG_FEATURES_SUPPORTED)
Glenn Randers-Pehrson2ad31ae2000-12-15 08:54:42 -0600469 png_ptr->filter_type = (png_byte)filter_type;
Glenn Randers-Pehrson8b6a8892001-05-18 04:54:50 -0500470#endif
Glenn Randers-Pehrson5b5dcf82004-07-17 22:45:44 -0500471 png_ptr->compression_type = (png_byte)compression_type;
Guy Schalnate5a37791996-06-05 15:50:50 -0500472 png_ptr->width = width;
473 png_ptr->height = height;
474
475 png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
Glenn Randers-Pehrson272489d2004-08-04 06:34:52 -0500476 png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
Guy Schalnate5a37791996-06-05 15:50:50 -0500477 /* set the usr info, so any transformations can modify it */
478 png_ptr->usr_width = png_ptr->width;
479 png_ptr->usr_bit_depth = png_ptr->bit_depth;
480 png_ptr->usr_channels = png_ptr->channels;
481
Guy Schalnat0d580581995-07-20 02:43:20 -0500482 /* pack the header information into the buffer */
483 png_save_uint_32(buf, width);
484 png_save_uint_32(buf + 4, height);
Guy Schalnatb2e01bd1996-01-26 01:38:47 -0600485 buf[8] = (png_byte)bit_depth;
486 buf[9] = (png_byte)color_type;
487 buf[10] = (png_byte)compression_type;
488 buf[11] = (png_byte)filter_type;
489 buf[12] = (png_byte)interlace_type;
Guy Schalnat0d580581995-07-20 02:43:20 -0500490
491 /* write the chunk */
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -0600492 png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500493
Andreas Dilger47a0c421997-05-16 02:46:07 -0500494 /* initialize zlib with PNG info */
Andreas Dilger02ad0ef1997-01-17 01:34:35 -0600495 png_ptr->zstream.zalloc = png_zalloc;
496 png_ptr->zstream.zfree = png_zfree;
497 png_ptr->zstream.opaque = (voidpf)png_ptr;
Guy Schalnate5a37791996-06-05 15:50:50 -0500498 if (!(png_ptr->do_filter))
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500499 {
Andreas Dilger47a0c421997-05-16 02:46:07 -0500500 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
501 png_ptr->bit_depth < 8)
Guy Schalnate5a37791996-06-05 15:50:50 -0500502 png_ptr->do_filter = PNG_FILTER_NONE;
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500503 else
Guy Schalnate5a37791996-06-05 15:50:50 -0500504 png_ptr->do_filter = PNG_ALL_FILTERS;
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500505 }
Guy Schalnate5a37791996-06-05 15:50:50 -0500506 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500507 {
Guy Schalnate5a37791996-06-05 15:50:50 -0500508 if (png_ptr->do_filter != PNG_FILTER_NONE)
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500509 png_ptr->zlib_strategy = Z_FILTERED;
510 else
511 png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
512 }
Guy Schalnate5a37791996-06-05 15:50:50 -0500513 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500514 png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
Guy Schalnate5a37791996-06-05 15:50:50 -0500515 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500516 png_ptr->zlib_mem_level = 8;
Guy Schalnate5a37791996-06-05 15:50:50 -0500517 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
Glenn Randers-Pehrson5b779162004-09-04 13:25:08 -0500518 png_ptr->zlib_window_bits = 15;
Guy Schalnate5a37791996-06-05 15:50:50 -0500519 if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500520 png_ptr->zlib_method = 8;
Andreas Dilger02ad0ef1997-01-17 01:34:35 -0600521 deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
Andreas Dilger47a0c421997-05-16 02:46:07 -0500522 png_ptr->zlib_method, png_ptr->zlib_window_bits,
523 png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
Andreas Dilger02ad0ef1997-01-17 01:34:35 -0600524 png_ptr->zstream.next_out = png_ptr->zbuf;
525 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
Glenn Randers-Pehrson878b31e2004-11-12 22:04:56 -0600526 /* libpng is not interested in zstream.data_type */
527 /* set it to a predefined value, to avoid its evaluation inside zlib */
528 png_ptr->zstream.data_type = Z_BINARY;
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500529
Guy Schalnate5a37791996-06-05 15:50:50 -0500530 png_ptr->mode = PNG_HAVE_IHDR;
Guy Schalnat0d580581995-07-20 02:43:20 -0500531}
532
533/* write the palette. We are careful not to trust png_color to be in the
Glenn Randers-Pehrson345bc271998-06-14 14:43:31 -0500534 * correct order for PNG, so people can redefine it to any convenient
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -0600535 * structure.
536 */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500537void /* PRIVATE */
Andreas Dilger47a0c421997-05-16 02:46:07 -0500538png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
Guy Schalnat0d580581995-07-20 02:43:20 -0500539{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -0600540#ifdef PNG_USE_LOCAL_ARRAYS
541 PNG_PLTE;
542#endif
Andreas Dilger47a0c421997-05-16 02:46:07 -0500543 png_uint_32 i;
Guy Schalnatb2e01bd1996-01-26 01:38:47 -0600544 png_colorp pal_ptr;
Guy Schalnat0d580581995-07-20 02:43:20 -0500545 png_byte buf[3];
546
Andreas Dilger47a0c421997-05-16 02:46:07 -0500547 png_debug(1, "in png_write_PLTE\n");
Glenn Randers-Pehrson4393a9a1999-09-17 12:27:26 -0500548 if ((
Glenn Randers-Pehrson1fd5fb32001-05-06 05:34:26 -0500549#if defined(PNG_MNG_FEATURES_SUPPORTED)
Glenn Randers-Pehrson5e5c1e12000-11-10 12:26:19 -0600550 !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
Glenn Randers-Pehrson4393a9a1999-09-17 12:27:26 -0500551#endif
552 num_pal == 0) || num_pal > 256)
Glenn Randers-Pehrson3097f612001-05-07 14:52:45 -0500553 {
554 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
Glenn Randers-Pehrson4393a9a1999-09-17 12:27:26 -0500555 {
Glenn Randers-Pehrson3097f612001-05-07 14:52:45 -0500556 png_error(png_ptr, "Invalid number of colors in palette");
557 }
558 else
559 {
560 png_warning(png_ptr, "Invalid number of colors in palette");
561 return;
562 }
563 }
564
565 if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
566 {
567 png_warning(png_ptr,
568 "Ignoring request to write a PLTE chunk in grayscale PNG");
569 return;
Guy Schalnate5a37791996-06-05 15:50:50 -0500570 }
571
Andreas Dilger47a0c421997-05-16 02:46:07 -0500572 png_ptr->num_palette = (png_uint_16)num_pal;
573 png_debug1(3, "num_palette = %d\n", png_ptr->num_palette);
Guy Schalnate5a37791996-06-05 15:50:50 -0500574
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -0600575 png_write_chunk_start(png_ptr, (png_bytep)png_PLTE, num_pal * 3);
Glenn Randers-Pehrsond4366722000-06-04 14:29:29 -0500576#ifndef PNG_NO_POINTER_INDEXING
Andreas Dilger47a0c421997-05-16 02:46:07 -0500577 for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
Guy Schalnat0d580581995-07-20 02:43:20 -0500578 {
579 buf[0] = pal_ptr->red;
580 buf[1] = pal_ptr->green;
581 buf[2] = pal_ptr->blue;
Andreas Dilger47a0c421997-05-16 02:46:07 -0500582 png_write_chunk_data(png_ptr, buf, (png_size_t)3);
Guy Schalnat0d580581995-07-20 02:43:20 -0500583 }
Glenn Randers-Pehrsond4366722000-06-04 14:29:29 -0500584#else
585 /* This is a little slower but some buggy compilers need to do this instead */
586 pal_ptr=palette;
587 for (i = 0; i < num_pal; i++)
588 {
589 buf[0] = pal_ptr[i].red;
590 buf[1] = pal_ptr[i].green;
591 buf[2] = pal_ptr[i].blue;
592 png_write_chunk_data(png_ptr, buf, (png_size_t)3);
593 }
594#endif
Guy Schalnat0d580581995-07-20 02:43:20 -0500595 png_write_chunk_end(png_ptr);
Guy Schalnate5a37791996-06-05 15:50:50 -0500596 png_ptr->mode |= PNG_HAVE_PLTE;
Guy Schalnat0d580581995-07-20 02:43:20 -0500597}
598
599/* write an IDAT chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500600void /* PRIVATE */
Andreas Dilger47a0c421997-05-16 02:46:07 -0500601png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
Guy Schalnat0d580581995-07-20 02:43:20 -0500602{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -0600603#ifdef PNG_USE_LOCAL_ARRAYS
604 PNG_IDAT;
605#endif
Andreas Dilger47a0c421997-05-16 02:46:07 -0500606 png_debug(1, "in png_write_IDAT\n");
Glenn Randers-Pehrson5b5dcf82004-07-17 22:45:44 -0500607
Glenn Randers-Pehrson5b779162004-09-04 13:25:08 -0500608 /* Optimize the CMF field in the zlib stream. */
609 /* This hack of the zlib stream is compliant to the stream specification. */
610 if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
611 png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
612 {
613 unsigned int z_cmf = data[0]; /* zlib compression method and flags */
614 if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
615 {
616 /* Avoid memory underflows and multiplication overflows. */
617 /* The conditions below are practically always satisfied;
618 however, they still must be checked. */
619 if (length >= 2 &&
620 png_ptr->height < 16384 && png_ptr->width < 16384)
621 {
622 png_uint_32 uncompressed_idat_size = png_ptr->height *
623 ((png_ptr->width *
624 png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
625 unsigned int z_cinfo = z_cmf >> 4;
626 unsigned int half_z_window_size = 1 << (z_cinfo + 7);
627 while (uncompressed_idat_size <= half_z_window_size &&
628 half_z_window_size >= 256)
629 {
630 z_cinfo--;
631 half_z_window_size >>= 1;
632 }
633 z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
634 if (data[0] != (png_byte)z_cmf)
635 {
636 data[0] = (png_byte)z_cmf;
637 data[1] &= 0xe0;
638 data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f);
639 }
640 }
641 }
642 else
643 png_error(png_ptr,
644 "Invalid zlib compression method or flags in IDAT");
645 }
646
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -0600647 png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
Guy Schalnate5a37791996-06-05 15:50:50 -0500648 png_ptr->mode |= PNG_HAVE_IDAT;
Guy Schalnat0d580581995-07-20 02:43:20 -0500649}
650
651/* write an IEND chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500652void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -0600653png_write_IEND(png_structp png_ptr)
Guy Schalnat0d580581995-07-20 02:43:20 -0500654{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -0600655#ifdef PNG_USE_LOCAL_ARRAYS
656 PNG_IEND;
657#endif
Andreas Dilger47a0c421997-05-16 02:46:07 -0500658 png_debug(1, "in png_write_IEND\n");
Glenn Randers-Pehrson3f549252001-10-27 07:35:13 -0500659 png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,
Glenn Randers-Pehrson6c97ddb2001-10-24 22:01:19 -0500660 (png_size_t)0);
Andreas Dilger02ad0ef1997-01-17 01:34:35 -0600661 png_ptr->mode |= PNG_HAVE_IEND;
Guy Schalnat0d580581995-07-20 02:43:20 -0500662}
663
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500664#if defined(PNG_WRITE_gAMA_SUPPORTED)
Guy Schalnat0d580581995-07-20 02:43:20 -0500665/* write a gAMA chunk */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600666#ifdef PNG_FLOATING_POINT_SUPPORTED
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500667void /* PRIVATE */
Andreas Dilger47a0c421997-05-16 02:46:07 -0500668png_write_gAMA(png_structp png_ptr, double file_gamma)
Guy Schalnat0d580581995-07-20 02:43:20 -0500669{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -0600670#ifdef PNG_USE_LOCAL_ARRAYS
671 PNG_gAMA;
672#endif
Guy Schalnat0d580581995-07-20 02:43:20 -0500673 png_uint_32 igamma;
674 png_byte buf[4];
675
Andreas Dilger47a0c421997-05-16 02:46:07 -0500676 png_debug(1, "in png_write_gAMA\n");
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600677 /* file_gamma is saved in 1/100,000ths */
Glenn Randers-Pehrson397100e1998-03-07 19:45:37 -0600678 igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
Guy Schalnat0d580581995-07-20 02:43:20 -0500679 png_save_uint_32(buf, igamma);
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -0600680 png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
Guy Schalnat0d580581995-07-20 02:43:20 -0500681}
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500682#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600683#ifdef PNG_FIXED_POINT_SUPPORTED
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500684void /* PRIVATE */
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600685png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600686{
687#ifdef PNG_USE_LOCAL_ARRAYS
688 PNG_gAMA;
689#endif
690 png_byte buf[4];
691
692 png_debug(1, "in png_write_gAMA\n");
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600693 /* file_gamma is saved in 1/100,000ths */
Glenn Randers-Pehrsonb1828932001-06-23 08:03:17 -0500694 png_save_uint_32(buf, (png_uint_32)file_gamma);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600695 png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
696}
697#endif
698#endif
Guy Schalnat0d580581995-07-20 02:43:20 -0500699
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -0600700#if defined(PNG_WRITE_sRGB_SUPPORTED)
701/* write a sRGB chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500702void /* PRIVATE */
Glenn Randers-Pehrsonc4a2ae61998-01-16 22:06:18 -0600703png_write_sRGB(png_structp png_ptr, int srgb_intent)
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -0600704{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -0600705#ifdef PNG_USE_LOCAL_ARRAYS
706 PNG_sRGB;
707#endif
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -0600708 png_byte buf[1];
709
710 png_debug(1, "in png_write_sRGB\n");
Glenn Randers-Pehrson46f61e21998-01-30 21:45:12 -0600711 if(srgb_intent >= PNG_sRGB_INTENT_LAST)
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -0600712 png_warning(png_ptr,
713 "Invalid sRGB rendering intent specified");
Glenn Randers-Pehrsonc4a2ae61998-01-16 22:06:18 -0600714 buf[0]=(png_byte)srgb_intent;
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -0600715 png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -0600716}
717#endif
718
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600719#if defined(PNG_WRITE_iCCP_SUPPORTED)
720/* write an iCCP chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500721void /* PRIVATE */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600722png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
723 png_charp profile, int profile_len)
724{
725#ifdef PNG_USE_LOCAL_ARRAYS
726 PNG_iCCP;
727#endif
728 png_size_t name_len;
729 png_charp new_name;
730 compression_state comp;
731
732 png_debug(1, "in png_write_iCCP\n");
Glenn Randers-Pehrson9c3ab682006-02-20 22:09:05 -0600733
734 comp.num_output_ptr = 0;
735 comp.max_output_ptr = 0;
736 comp.output_ptr = NULL;
737 comp.input = NULL;
738 comp.input_len = 0;
739
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600740 if (name == NULL || (name_len = png_check_keyword(png_ptr, name,
741 &new_name)) == 0)
742 {
743 png_warning(png_ptr, "Empty keyword in iCCP chunk");
744 return;
745 }
746
Glenn Randers-Pehrson76e5fd62000-12-28 07:50:05 -0600747 if (compression_type != PNG_COMPRESSION_TYPE_BASE)
Glenn Randers-Pehrson520a7642000-03-21 05:13:06 -0600748 png_warning(png_ptr, "Unknown compression type in iCCP chunk");
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600749
Glenn Randers-Pehrson13944802000-06-24 07:42:42 -0500750 if (profile == NULL)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600751 profile_len = 0;
752
753 if (profile_len)
Glenn Randers-Pehrson6942d532000-05-01 09:31:54 -0500754 profile_len = png_text_compress(png_ptr, profile, (png_size_t)profile_len,
Glenn Randers-Pehrson76e5fd62000-12-28 07:50:05 -0600755 PNG_COMPRESSION_TYPE_BASE, &comp);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600756
757 /* make sure we include the NULL after the name and the compression type */
758 png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
759 (png_uint_32)name_len+profile_len+2);
Glenn Randers-Pehrson5e5c1e12000-11-10 12:26:19 -0600760 new_name[name_len+1]=0x00;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600761 png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 2);
762
763 if (profile_len)
764 png_write_compressed_data_out(png_ptr, &comp);
765
766 png_write_chunk_end(png_ptr);
767 png_free(png_ptr, new_name);
768}
769#endif
770
771#if defined(PNG_WRITE_sPLT_SUPPORTED)
772/* write a sPLT chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500773void /* PRIVATE */
Glenn Randers-Pehrson520a7642000-03-21 05:13:06 -0600774png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600775{
776#ifdef PNG_USE_LOCAL_ARRAYS
777 PNG_sPLT;
778#endif
779 png_size_t name_len;
780 png_charp new_name;
781 png_byte entrybuf[10];
782 int entry_size = (spalette->depth == 8 ? 6 : 10);
783 int palette_size = entry_size * spalette->nentries;
Glenn Randers-Pehrson520a7642000-03-21 05:13:06 -0600784 png_sPLT_entryp ep;
Glenn Randers-Pehrsond4366722000-06-04 14:29:29 -0500785#ifdef PNG_NO_POINTER_INDEXING
786 int i;
787#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600788
789 png_debug(1, "in png_write_sPLT\n");
Glenn Randers-Pehrson520a7642000-03-21 05:13:06 -0600790 if (spalette->name == NULL || (name_len = png_check_keyword(png_ptr,
791 spalette->name, &new_name))==0)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600792 {
793 png_warning(png_ptr, "Empty keyword in sPLT chunk");
794 return;
795 }
796
797 /* make sure we include the NULL after the name */
Glenn Randers-Pehrson3097f612001-05-07 14:52:45 -0500798 png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600799 (png_uint_32)(name_len + 2 + palette_size));
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600800 png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 1);
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600801 png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, 1);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600802
803 /* loop through each palette entry, writing appropriately */
Glenn Randers-Pehrsond4366722000-06-04 14:29:29 -0500804#ifndef PNG_NO_POINTER_INDEXING
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600805 for (ep = spalette->entries; ep<spalette->entries+spalette->nentries; ep++)
806 {
807 if (spalette->depth == 8)
808 {
809 entrybuf[0] = (png_byte)ep->red;
810 entrybuf[1] = (png_byte)ep->green;
811 entrybuf[2] = (png_byte)ep->blue;
812 entrybuf[3] = (png_byte)ep->alpha;
813 png_save_uint_16(entrybuf + 4, ep->frequency);
814 }
815 else
816 {
817 png_save_uint_16(entrybuf + 0, ep->red);
818 png_save_uint_16(entrybuf + 2, ep->green);
819 png_save_uint_16(entrybuf + 4, ep->blue);
820 png_save_uint_16(entrybuf + 6, ep->alpha);
821 png_save_uint_16(entrybuf + 8, ep->frequency);
822 }
Glenn Randers-Pehrsonb1828932001-06-23 08:03:17 -0500823 png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600824 }
Glenn Randers-Pehrsond4366722000-06-04 14:29:29 -0500825#else
826 ep=spalette->entries;
827 for (i=0; i>spalette->nentries; i++)
828 {
829 if (spalette->depth == 8)
830 {
831 entrybuf[0] = (png_byte)ep[i].red;
832 entrybuf[1] = (png_byte)ep[i].green;
833 entrybuf[2] = (png_byte)ep[i].blue;
834 entrybuf[3] = (png_byte)ep[i].alpha;
835 png_save_uint_16(entrybuf + 4, ep[i].frequency);
836 }
837 else
838 {
839 png_save_uint_16(entrybuf + 0, ep[i].red);
840 png_save_uint_16(entrybuf + 2, ep[i].green);
841 png_save_uint_16(entrybuf + 4, ep[i].blue);
842 png_save_uint_16(entrybuf + 6, ep[i].alpha);
843 png_save_uint_16(entrybuf + 8, ep[i].frequency);
844 }
845 png_write_chunk_data(png_ptr, entrybuf, entry_size);
846 }
847#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600848
849 png_write_chunk_end(png_ptr);
850 png_free(png_ptr, new_name);
851}
852#endif
853
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500854#if defined(PNG_WRITE_sBIT_SUPPORTED)
Guy Schalnat0d580581995-07-20 02:43:20 -0500855/* write the sBIT chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500856void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -0600857png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
Guy Schalnat0d580581995-07-20 02:43:20 -0500858{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -0600859#ifdef PNG_USE_LOCAL_ARRAYS
860 PNG_sBIT;
861#endif
Guy Schalnat0d580581995-07-20 02:43:20 -0500862 png_byte buf[4];
Andreas Dilger47a0c421997-05-16 02:46:07 -0500863 png_size_t size;
Guy Schalnat0d580581995-07-20 02:43:20 -0500864
Andreas Dilger47a0c421997-05-16 02:46:07 -0500865 png_debug(1, "in png_write_sBIT\n");
Guy Schalnat6d764711995-12-19 03:22:19 -0600866 /* make sure we don't depend upon the order of PNG_COLOR_8 */
Guy Schalnat0d580581995-07-20 02:43:20 -0500867 if (color_type & PNG_COLOR_MASK_COLOR)
868 {
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -0600869 png_byte maxbits;
Guy Schalnate5a37791996-06-05 15:50:50 -0500870
Glenn Randers-Pehrson860ab2b1999-10-14 07:43:10 -0500871 maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
872 png_ptr->usr_bit_depth);
Glenn Randers-Pehrson5c6aeb21998-12-29 11:47:59 -0600873 if (sbit->red == 0 || sbit->red > maxbits ||
874 sbit->green == 0 || sbit->green > maxbits ||
Guy Schalnate5a37791996-06-05 15:50:50 -0500875 sbit->blue == 0 || sbit->blue > maxbits)
876 {
877 png_warning(png_ptr, "Invalid sBIT depth specified");
878 return;
879 }
Guy Schalnat0d580581995-07-20 02:43:20 -0500880 buf[0] = sbit->red;
881 buf[1] = sbit->green;
882 buf[2] = sbit->blue;
883 size = 3;
884 }
885 else
886 {
Guy Schalnate5a37791996-06-05 15:50:50 -0500887 if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
888 {
889 png_warning(png_ptr, "Invalid sBIT depth specified");
890 return;
891 }
Guy Schalnat0d580581995-07-20 02:43:20 -0500892 buf[0] = sbit->gray;
893 size = 1;
894 }
895
896 if (color_type & PNG_COLOR_MASK_ALPHA)
897 {
Guy Schalnate5a37791996-06-05 15:50:50 -0500898 if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
899 {
900 png_warning(png_ptr, "Invalid sBIT depth specified");
901 return;
902 }
Guy Schalnat0d580581995-07-20 02:43:20 -0500903 buf[size++] = sbit->alpha;
904 }
905
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -0600906 png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
Guy Schalnat0d580581995-07-20 02:43:20 -0500907}
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500908#endif
Guy Schalnat0d580581995-07-20 02:43:20 -0500909
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500910#if defined(PNG_WRITE_cHRM_SUPPORTED)
Guy Schalnat0d580581995-07-20 02:43:20 -0500911/* write the cHRM chunk */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600912#ifdef PNG_FLOATING_POINT_SUPPORTED
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500913void /* PRIVATE */
Andreas Dilger47a0c421997-05-16 02:46:07 -0500914png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
Guy Schalnatb2e01bd1996-01-26 01:38:47 -0600915 double red_x, double red_y, double green_x, double green_y,
916 double blue_x, double blue_y)
Guy Schalnat0d580581995-07-20 02:43:20 -0500917{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -0600918#ifdef PNG_USE_LOCAL_ARRAYS
919 PNG_cHRM;
920#endif
Guy Schalnat0d580581995-07-20 02:43:20 -0500921 png_byte buf[32];
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600922 png_uint_32 itemp;
Guy Schalnat0d580581995-07-20 02:43:20 -0500923
Andreas Dilger47a0c421997-05-16 02:46:07 -0500924 png_debug(1, "in png_write_cHRM\n");
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600925 /* each value is saved in 1/100,000ths */
Guy Schalnate5a37791996-06-05 15:50:50 -0500926 if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 ||
927 white_x + white_y > 1.0)
928 {
929 png_warning(png_ptr, "Invalid cHRM white point specified");
Glenn Randers-Pehrson316f97a2000-07-08 13:19:41 -0500930#if !defined(PNG_NO_CONSOLE_IO)
931 fprintf(stderr,"white_x=%f, white_y=%f\n",white_x, white_y);
Glenn Randers-Pehrson68ea2432000-04-01 21:10:05 -0600932#endif
Guy Schalnate5a37791996-06-05 15:50:50 -0500933 return;
934 }
Glenn Randers-Pehrson397100e1998-03-07 19:45:37 -0600935 itemp = (png_uint_32)(white_x * 100000.0 + 0.5);
Guy Schalnat0d580581995-07-20 02:43:20 -0500936 png_save_uint_32(buf, itemp);
Glenn Randers-Pehrson397100e1998-03-07 19:45:37 -0600937 itemp = (png_uint_32)(white_y * 100000.0 + 0.5);
Guy Schalnat0d580581995-07-20 02:43:20 -0500938 png_save_uint_32(buf + 4, itemp);
Guy Schalnate5a37791996-06-05 15:50:50 -0500939
Glenn Randers-Pehrsonddfebd32006-02-22 09:19:25 -0600940 if (red_x < 0 || red_y < 0 || red_x + red_y > 1.0)
Guy Schalnate5a37791996-06-05 15:50:50 -0500941 {
942 png_warning(png_ptr, "Invalid cHRM red point specified");
943 return;
944 }
Glenn Randers-Pehrson397100e1998-03-07 19:45:37 -0600945 itemp = (png_uint_32)(red_x * 100000.0 + 0.5);
Guy Schalnat0d580581995-07-20 02:43:20 -0500946 png_save_uint_32(buf + 8, itemp);
Glenn Randers-Pehrson397100e1998-03-07 19:45:37 -0600947 itemp = (png_uint_32)(red_y * 100000.0 + 0.5);
Guy Schalnat0d580581995-07-20 02:43:20 -0500948 png_save_uint_32(buf + 12, itemp);
Guy Schalnate5a37791996-06-05 15:50:50 -0500949
Glenn Randers-Pehrsonddfebd32006-02-22 09:19:25 -0600950 if (green_x < 0 || green_y < 0 || green_x + green_y > 1.0)
Guy Schalnate5a37791996-06-05 15:50:50 -0500951 {
952 png_warning(png_ptr, "Invalid cHRM green point specified");
953 return;
954 }
Glenn Randers-Pehrson397100e1998-03-07 19:45:37 -0600955 itemp = (png_uint_32)(green_x * 100000.0 + 0.5);
Guy Schalnat0d580581995-07-20 02:43:20 -0500956 png_save_uint_32(buf + 16, itemp);
Glenn Randers-Pehrson397100e1998-03-07 19:45:37 -0600957 itemp = (png_uint_32)(green_y * 100000.0 + 0.5);
Guy Schalnat0d580581995-07-20 02:43:20 -0500958 png_save_uint_32(buf + 20, itemp);
Guy Schalnate5a37791996-06-05 15:50:50 -0500959
Glenn Randers-Pehrsonddfebd32006-02-22 09:19:25 -0600960 if (blue_x < 0 || blue_y < 0 || blue_x + blue_y > 1.0)
Guy Schalnate5a37791996-06-05 15:50:50 -0500961 {
962 png_warning(png_ptr, "Invalid cHRM blue point specified");
963 return;
964 }
Glenn Randers-Pehrson397100e1998-03-07 19:45:37 -0600965 itemp = (png_uint_32)(blue_x * 100000.0 + 0.5);
Guy Schalnat0d580581995-07-20 02:43:20 -0500966 png_save_uint_32(buf + 24, itemp);
Glenn Randers-Pehrson397100e1998-03-07 19:45:37 -0600967 itemp = (png_uint_32)(blue_y * 100000.0 + 0.5);
Guy Schalnat0d580581995-07-20 02:43:20 -0500968 png_save_uint_32(buf + 28, itemp);
Guy Schalnate5a37791996-06-05 15:50:50 -0500969
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -0600970 png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
Guy Schalnat0d580581995-07-20 02:43:20 -0500971}
Guy Schalnat51f0eb41995-09-26 05:22:39 -0500972#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600973#ifdef PNG_FIXED_POINT_SUPPORTED
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -0500974void /* PRIVATE */
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600975png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
976 png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
977 png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
978 png_fixed_point blue_y)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600979{
980#ifdef PNG_USE_LOCAL_ARRAYS
981 PNG_cHRM;
982#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600983 png_byte buf[32];
984
985 png_debug(1, "in png_write_cHRM\n");
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600986 /* each value is saved in 1/100,000ths */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600987 if (white_x > 80000L || white_y > 80000L || white_x + white_y > 100000L)
988 {
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -0600989 png_warning(png_ptr, "Invalid fixed cHRM white point specified");
Glenn Randers-Pehrson316f97a2000-07-08 13:19:41 -0500990#if !defined(PNG_NO_CONSOLE_IO)
991 fprintf(stderr,"white_x=%ld, white_y=%ld\n",white_x, white_y);
Glenn Randers-Pehrson68ea2432000-04-01 21:10:05 -0600992#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600993 return;
994 }
Glenn Randers-Pehrsonb1828932001-06-23 08:03:17 -0500995 png_save_uint_32(buf, (png_uint_32)white_x);
996 png_save_uint_32(buf + 4, (png_uint_32)white_y);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600997
Glenn Randers-Pehrsonddfebd32006-02-22 09:19:25 -0600998 if (red_x + red_y > 100000L)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -0600999 {
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001000 png_warning(png_ptr, "Invalid cHRM fixed red point specified");
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001001 return;
1002 }
Glenn Randers-Pehrsonb1828932001-06-23 08:03:17 -05001003 png_save_uint_32(buf + 8, (png_uint_32)red_x);
1004 png_save_uint_32(buf + 12, (png_uint_32)red_y);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001005
Glenn Randers-Pehrsonddfebd32006-02-22 09:19:25 -06001006 if (green_x + green_y > 100000L)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001007 {
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001008 png_warning(png_ptr, "Invalid fixed cHRM green point specified");
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001009 return;
1010 }
Glenn Randers-Pehrsonb1828932001-06-23 08:03:17 -05001011 png_save_uint_32(buf + 16, (png_uint_32)green_x);
1012 png_save_uint_32(buf + 20, (png_uint_32)green_y);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001013
Glenn Randers-Pehrsonddfebd32006-02-22 09:19:25 -06001014 if (blue_x + blue_y > 100000L)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001015 {
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001016 png_warning(png_ptr, "Invalid fixed cHRM blue point specified");
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001017 return;
1018 }
Glenn Randers-Pehrsonb1828932001-06-23 08:03:17 -05001019 png_save_uint_32(buf + 24, (png_uint_32)blue_x);
1020 png_save_uint_32(buf + 28, (png_uint_32)blue_y);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001021
1022 png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
1023}
1024#endif
1025#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001026
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001027#if defined(PNG_WRITE_tRNS_SUPPORTED)
Guy Schalnat0d580581995-07-20 02:43:20 -05001028/* write the tRNS chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001029void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -06001030png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
Guy Schalnat0d580581995-07-20 02:43:20 -05001031 int num_trans, int color_type)
1032{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001033#ifdef PNG_USE_LOCAL_ARRAYS
1034 PNG_tRNS;
1035#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001036 png_byte buf[6];
1037
Andreas Dilger47a0c421997-05-16 02:46:07 -05001038 png_debug(1, "in png_write_tRNS\n");
Guy Schalnat0d580581995-07-20 02:43:20 -05001039 if (color_type == PNG_COLOR_TYPE_PALETTE)
1040 {
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001041 if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
Guy Schalnate5a37791996-06-05 15:50:50 -05001042 {
1043 png_warning(png_ptr,"Invalid number of transparent colors specified");
1044 return;
1045 }
Guy Schalnat0d580581995-07-20 02:43:20 -05001046 /* write the chunk out as it is */
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001047 png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans, (png_size_t)num_trans);
Guy Schalnat0d580581995-07-20 02:43:20 -05001048 }
1049 else if (color_type == PNG_COLOR_TYPE_GRAY)
1050 {
1051 /* one 16 bit value */
Glenn Randers-Pehrson1ea0ff32001-08-07 22:25:59 -05001052 if(tran->gray >= (1 << png_ptr->bit_depth))
1053 {
1054 png_warning(png_ptr,
1055 "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
1056 return;
1057 }
Guy Schalnat0d580581995-07-20 02:43:20 -05001058 png_save_uint_16(buf, tran->gray);
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001059 png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
Guy Schalnat0d580581995-07-20 02:43:20 -05001060 }
1061 else if (color_type == PNG_COLOR_TYPE_RGB)
1062 {
1063 /* three 16 bit values */
1064 png_save_uint_16(buf, tran->red);
1065 png_save_uint_16(buf + 2, tran->green);
1066 png_save_uint_16(buf + 4, tran->blue);
Glenn Randers-Pehrson1ea0ff32001-08-07 22:25:59 -05001067 if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1068 {
1069 png_warning(png_ptr,
1070 "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
1071 return;
1072 }
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001073 png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
Guy Schalnat0d580581995-07-20 02:43:20 -05001074 }
Guy Schalnate5a37791996-06-05 15:50:50 -05001075 else
1076 {
Glenn Randers-Pehrsonc4a2ae61998-01-16 22:06:18 -06001077 png_warning(png_ptr, "Can't write tRNS with an alpha channel");
Guy Schalnate5a37791996-06-05 15:50:50 -05001078 }
Guy Schalnat0d580581995-07-20 02:43:20 -05001079}
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001080#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001081
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001082#if defined(PNG_WRITE_bKGD_SUPPORTED)
Guy Schalnat0d580581995-07-20 02:43:20 -05001083/* write the background chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001084void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -06001085png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
Guy Schalnat0d580581995-07-20 02:43:20 -05001086{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001087#ifdef PNG_USE_LOCAL_ARRAYS
1088 PNG_bKGD;
1089#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001090 png_byte buf[6];
1091
Andreas Dilger47a0c421997-05-16 02:46:07 -05001092 png_debug(1, "in png_write_bKGD\n");
Guy Schalnat0d580581995-07-20 02:43:20 -05001093 if (color_type == PNG_COLOR_TYPE_PALETTE)
1094 {
Glenn Randers-Pehrson4393a9a1999-09-17 12:27:26 -05001095 if (
Glenn Randers-Pehrson1fd5fb32001-05-06 05:34:26 -05001096#if defined(PNG_MNG_FEATURES_SUPPORTED)
Glenn Randers-Pehrson5e5c1e12000-11-10 12:26:19 -06001097 (png_ptr->num_palette ||
1098 (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
Glenn Randers-Pehrson4393a9a1999-09-17 12:27:26 -05001099#endif
1100 back->index > png_ptr->num_palette)
Guy Schalnate5a37791996-06-05 15:50:50 -05001101 {
1102 png_warning(png_ptr, "Invalid background palette index");
1103 return;
1104 }
Guy Schalnat0d580581995-07-20 02:43:20 -05001105 buf[0] = back->index;
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001106 png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
Guy Schalnat0d580581995-07-20 02:43:20 -05001107 }
1108 else if (color_type & PNG_COLOR_MASK_COLOR)
1109 {
1110 png_save_uint_16(buf, back->red);
1111 png_save_uint_16(buf + 2, back->green);
1112 png_save_uint_16(buf + 4, back->blue);
Glenn Randers-Pehrson1ea0ff32001-08-07 22:25:59 -05001113 if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1114 {
1115 png_warning(png_ptr,
1116 "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
1117 return;
1118 }
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001119 png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
Guy Schalnat0d580581995-07-20 02:43:20 -05001120 }
1121 else
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001122 {
Glenn Randers-Pehrson1ea0ff32001-08-07 22:25:59 -05001123 if(back->gray >= (1 << png_ptr->bit_depth))
1124 {
1125 png_warning(png_ptr,
1126 "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
1127 return;
1128 }
Guy Schalnat0d580581995-07-20 02:43:20 -05001129 png_save_uint_16(buf, back->gray);
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001130 png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
Guy Schalnat0d580581995-07-20 02:43:20 -05001131 }
1132}
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001133#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001134
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001135#if defined(PNG_WRITE_hIST_SUPPORTED)
Guy Schalnat0d580581995-07-20 02:43:20 -05001136/* write the histogram */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001137void /* PRIVATE */
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001138png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
Guy Schalnat0d580581995-07-20 02:43:20 -05001139{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001140#ifdef PNG_USE_LOCAL_ARRAYS
1141 PNG_hIST;
1142#endif
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001143 int i;
Guy Schalnat0d580581995-07-20 02:43:20 -05001144 png_byte buf[3];
1145
Andreas Dilger47a0c421997-05-16 02:46:07 -05001146 png_debug(1, "in png_write_hIST\n");
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001147 if (num_hist > (int)png_ptr->num_palette)
Guy Schalnate5a37791996-06-05 15:50:50 -05001148 {
Andreas Dilger47a0c421997-05-16 02:46:07 -05001149 png_debug2(3, "num_hist = %d, num_palette = %d\n", num_hist,
1150 png_ptr->num_palette);
Guy Schalnate5a37791996-06-05 15:50:50 -05001151 png_warning(png_ptr, "Invalid number of histogram entries specified");
1152 return;
1153 }
1154
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001155 png_write_chunk_start(png_ptr, (png_bytep)png_hIST, (png_uint_32)(num_hist * 2));
Andreas Dilger47a0c421997-05-16 02:46:07 -05001156 for (i = 0; i < num_hist; i++)
Guy Schalnat0d580581995-07-20 02:43:20 -05001157 {
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001158 png_save_uint_16(buf, hist[i]);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001159 png_write_chunk_data(png_ptr, buf, (png_size_t)2);
Guy Schalnat0d580581995-07-20 02:43:20 -05001160 }
1161 png_write_chunk_end(png_ptr);
1162}
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001163#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001164
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001165#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
1166 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001167/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
1168 * and if invalid, correct the keyword rather than discarding the entire
1169 * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
1170 * length, forbids leading or trailing whitespace, multiple internal spaces,
1171 * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
Andreas Dilger47a0c421997-05-16 02:46:07 -05001172 *
1173 * The new_key is allocated to hold the corrected keyword and must be freed
1174 * by the calling routine. This avoids problems with trying to write to
1175 * static keywords without having to have duplicate copies of the strings.
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001176 */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001177png_size_t /* PRIVATE */
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06001178png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001179{
Andreas Dilger47a0c421997-05-16 02:46:07 -05001180 png_size_t key_len;
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06001181 png_charp kp, dp;
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001182 int kflag;
Glenn Randers-Pehrsonf6b4f452000-12-01 09:23:06 -06001183 int kwarn=0;
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001184
Andreas Dilger47a0c421997-05-16 02:46:07 -05001185 png_debug(1, "in png_check_keyword\n");
1186 *new_key = NULL;
1187
1188 if (key == NULL || (key_len = png_strlen(key)) == 0)
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001189 {
Glenn Randers-Pehrsonf6b4f452000-12-01 09:23:06 -06001190 png_warning(png_ptr, "zero length keyword");
Glenn Randers-Pehrsonb2120021998-01-31 20:07:59 -06001191 return ((png_size_t)0);
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001192 }
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001193
Andreas Dilger47a0c421997-05-16 02:46:07 -05001194 png_debug1(2, "Keyword to be checked is '%s'\n", key);
1195
Glenn Randers-Pehrson5fea36f2004-07-28 08:20:44 -05001196 *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
1197 if (*new_key == NULL)
1198 {
1199 png_warning(png_ptr, "Out of memory while procesing keyword");
1200 return ((png_size_t)0);
1201 }
Glenn Randers-Pehrsone68f5a32001-05-14 09:20:53 -05001202
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001203 /* Replace non-printing characters with a blank and print a warning */
Andreas Dilger47a0c421997-05-16 02:46:07 -05001204 for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001205 {
Glenn Randers-Pehrson70e3f541998-01-03 22:40:55 -06001206 if (*kp < 0x20 || (*kp > 0x7E && (png_byte)*kp < 0xA1))
Andreas Dilger47a0c421997-05-16 02:46:07 -05001207 {
Glenn Randers-Pehrson17218292006-04-20 07:20:46 -05001208#ifndef PNG_NO_STDIO
Andreas Dilger47a0c421997-05-16 02:46:07 -05001209 char msg[40];
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001210
Glenn Randers-Pehrson17218292006-04-20 07:20:46 -05001211 png_sprintf(msg, "invalid keyword character 0x%02X", *kp);
Glenn Randers-Pehrsonf6b4f452000-12-01 09:23:06 -06001212 png_warning(png_ptr, msg);
Glenn Randers-Pehrson70e3f541998-01-03 22:40:55 -06001213#else
Glenn Randers-Pehrsonf6b4f452000-12-01 09:23:06 -06001214 png_warning(png_ptr, "invalid character in keyword");
Glenn Randers-Pehrson70e3f541998-01-03 22:40:55 -06001215#endif
Andreas Dilger47a0c421997-05-16 02:46:07 -05001216 *dp = ' ';
1217 }
1218 else
1219 {
1220 *dp = *kp;
1221 }
1222 }
1223 *dp = '\0';
1224
1225 /* Remove any trailing white space. */
1226 kp = *new_key + key_len - 1;
1227 if (*kp == ' ')
1228 {
Glenn Randers-Pehrsonf6b4f452000-12-01 09:23:06 -06001229 png_warning(png_ptr, "trailing spaces removed from keyword");
Andreas Dilger47a0c421997-05-16 02:46:07 -05001230
1231 while (*kp == ' ')
1232 {
1233 *(kp--) = '\0';
1234 key_len--;
1235 }
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001236 }
1237
1238 /* Remove any leading white space. */
Andreas Dilger47a0c421997-05-16 02:46:07 -05001239 kp = *new_key;
1240 if (*kp == ' ')
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001241 {
Glenn Randers-Pehrsonf6b4f452000-12-01 09:23:06 -06001242 png_warning(png_ptr, "leading spaces removed from keyword");
Andreas Dilger47a0c421997-05-16 02:46:07 -05001243
1244 while (*kp == ' ')
1245 {
1246 kp++;
1247 key_len--;
1248 }
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001249 }
1250
Andreas Dilger47a0c421997-05-16 02:46:07 -05001251 png_debug1(2, "Checking for multiple internal spaces in '%s'\n", kp);
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001252
Andreas Dilger47a0c421997-05-16 02:46:07 -05001253 /* Remove multiple internal spaces. */
1254 for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001255 {
Andreas Dilger47a0c421997-05-16 02:46:07 -05001256 if (*kp == ' ' && kflag == 0)
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001257 {
Andreas Dilger47a0c421997-05-16 02:46:07 -05001258 *(dp++) = *kp;
1259 kflag = 1;
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001260 }
Andreas Dilger47a0c421997-05-16 02:46:07 -05001261 else if (*kp == ' ')
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001262 {
1263 key_len--;
Glenn Randers-Pehrsonf6b4f452000-12-01 09:23:06 -06001264 kwarn=1;
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001265 }
1266 else
1267 {
Andreas Dilger47a0c421997-05-16 02:46:07 -05001268 *(dp++) = *kp;
1269 kflag = 0;
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001270 }
1271 }
Andreas Dilger47a0c421997-05-16 02:46:07 -05001272 *dp = '\0';
Glenn Randers-Pehrsonf6b4f452000-12-01 09:23:06 -06001273 if(kwarn)
1274 png_warning(png_ptr, "extra interior spaces removed from keyword");
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001275
1276 if (key_len == 0)
Andreas Dilger47a0c421997-05-16 02:46:07 -05001277 {
Glenn Randers-Pehrson6d8f3b01999-10-23 08:39:18 -05001278 png_free(png_ptr, *new_key);
1279 *new_key=NULL;
Glenn Randers-Pehrsonf6b4f452000-12-01 09:23:06 -06001280 png_warning(png_ptr, "Zero length keyword");
Andreas Dilger47a0c421997-05-16 02:46:07 -05001281 }
1282
1283 if (key_len > 79)
1284 {
Glenn Randers-Pehrsonf6b4f452000-12-01 09:23:06 -06001285 png_warning(png_ptr, "keyword length must be 1 - 79 characters");
Andreas Dilger47a0c421997-05-16 02:46:07 -05001286 new_key[79] = '\0';
1287 key_len = 79;
1288 }
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001289
Glenn Randers-Pehrsonb2120021998-01-31 20:07:59 -06001290 return (key_len);
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001291}
1292#endif
1293
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001294#if defined(PNG_WRITE_tEXt_SUPPORTED)
Guy Schalnat0d580581995-07-20 02:43:20 -05001295/* write a tEXt chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001296void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -06001297png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
Andreas Dilger47a0c421997-05-16 02:46:07 -05001298 png_size_t text_len)
Guy Schalnat0d580581995-07-20 02:43:20 -05001299{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001300#ifdef PNG_USE_LOCAL_ARRAYS
1301 PNG_tEXt;
1302#endif
Andreas Dilger47a0c421997-05-16 02:46:07 -05001303 png_size_t key_len;
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06001304 png_charp new_key;
Guy Schalnat0d580581995-07-20 02:43:20 -05001305
Andreas Dilger47a0c421997-05-16 02:46:07 -05001306 png_debug(1, "in png_write_tEXt\n");
1307 if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1308 {
Glenn Randers-Pehrson70e3f541998-01-03 22:40:55 -06001309 png_warning(png_ptr, "Empty keyword in tEXt chunk");
Guy Schalnate5a37791996-06-05 15:50:50 -05001310 return;
Andreas Dilger47a0c421997-05-16 02:46:07 -05001311 }
Guy Schalnate5a37791996-06-05 15:50:50 -05001312
Andreas Dilger47a0c421997-05-16 02:46:07 -05001313 if (text == NULL || *text == '\0')
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001314 text_len = 0;
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001315 else
1316 text_len = png_strlen(text);
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001317
1318 /* make sure we include the 0 after the key */
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001319 png_write_chunk_start(png_ptr, (png_bytep)png_tEXt, (png_uint_32)key_len+text_len+1);
Glenn Randers-Pehrson4393a9a1999-09-17 12:27:26 -05001320 /*
1321 * We leave it to the application to meet PNG-1.0 requirements on the
1322 * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1323 * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001324 * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
Glenn Randers-Pehrson4393a9a1999-09-17 12:27:26 -05001325 */
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06001326 png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001327 if (text_len)
Andreas Dilger47a0c421997-05-16 02:46:07 -05001328 png_write_chunk_data(png_ptr, (png_bytep)text, text_len);
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001329
Guy Schalnat0d580581995-07-20 02:43:20 -05001330 png_write_chunk_end(png_ptr);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001331 png_free(png_ptr, new_key);
Guy Schalnat0d580581995-07-20 02:43:20 -05001332}
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001333#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001334
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001335#if defined(PNG_WRITE_zTXt_SUPPORTED)
Andreas Dilger47a0c421997-05-16 02:46:07 -05001336/* write a compressed text chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001337void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -06001338png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
Andreas Dilger47a0c421997-05-16 02:46:07 -05001339 png_size_t text_len, int compression)
Guy Schalnat0d580581995-07-20 02:43:20 -05001340{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001341#ifdef PNG_USE_LOCAL_ARRAYS
1342 PNG_zTXt;
1343#endif
Andreas Dilger47a0c421997-05-16 02:46:07 -05001344 png_size_t key_len;
Guy Schalnat0d580581995-07-20 02:43:20 -05001345 char buf[1];
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06001346 png_charp new_key;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001347 compression_state comp;
Guy Schalnat0d580581995-07-20 02:43:20 -05001348
Andreas Dilger47a0c421997-05-16 02:46:07 -05001349 png_debug(1, "in png_write_zTXt\n");
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001350
Glenn Randers-Pehrson9c3ab682006-02-20 22:09:05 -06001351 comp.num_output_ptr = 0;
1352 comp.max_output_ptr = 0;
1353 comp.output_ptr = NULL;
1354 comp.input = NULL;
1355 comp.input_len = 0;
1356
Andreas Dilger47a0c421997-05-16 02:46:07 -05001357 if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
Guy Schalnate5a37791996-06-05 15:50:50 -05001358 {
Glenn Randers-Pehrson70e3f541998-01-03 22:40:55 -06001359 png_warning(png_ptr, "Empty keyword in zTXt chunk");
Andreas Dilger47a0c421997-05-16 02:46:07 -05001360 return;
Guy Schalnate5a37791996-06-05 15:50:50 -05001361 }
1362
Andreas Dilger47a0c421997-05-16 02:46:07 -05001363 if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
1364 {
1365 png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
1366 png_free(png_ptr, new_key);
1367 return;
1368 }
1369
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001370 text_len = png_strlen(text);
1371
Andreas Dilger47a0c421997-05-16 02:46:07 -05001372 png_free(png_ptr, new_key);
1373
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001374 /* compute the compressed data; do it now for the length */
Glenn Randers-Pehrson6942d532000-05-01 09:31:54 -05001375 text_len = png_text_compress(png_ptr, text, text_len, compression,
1376 &comp);
Guy Schalnat0d580581995-07-20 02:43:20 -05001377
1378 /* write start of chunk */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001379 png_write_chunk_start(png_ptr, (png_bytep)png_zTXt, (png_uint_32)
1380 (key_len+text_len+2));
Guy Schalnat0d580581995-07-20 02:43:20 -05001381 /* write key */
Andreas Dilger47a0c421997-05-16 02:46:07 -05001382 png_write_chunk_data(png_ptr, (png_bytep)key, key_len + 1);
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001383 buf[0] = (png_byte)compression;
Guy Schalnat0d580581995-07-20 02:43:20 -05001384 /* write compression */
Andreas Dilger47a0c421997-05-16 02:46:07 -05001385 png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001386 /* write the compressed data */
1387 png_write_compressed_data_out(png_ptr, &comp);
Guy Schalnat0d580581995-07-20 02:43:20 -05001388
Guy Schalnat0d580581995-07-20 02:43:20 -05001389 /* close the chunk */
1390 png_write_chunk_end(png_ptr);
Guy Schalnat0d580581995-07-20 02:43:20 -05001391}
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001392#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001393
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001394#if defined(PNG_WRITE_iTXt_SUPPORTED)
1395/* write an iTXt chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001396void /* PRIVATE */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001397png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001398 png_charp lang, png_charp lang_key, png_charp text)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001399{
1400#ifdef PNG_USE_LOCAL_ARRAYS
1401 PNG_iTXt;
1402#endif
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001403 png_size_t lang_len, key_len, lang_key_len, text_len;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001404 png_charp new_lang, new_key;
1405 png_byte cbuf[2];
1406 compression_state comp;
1407
1408 png_debug(1, "in png_write_iTXt\n");
1409
Glenn Randers-Pehrson9c3ab682006-02-20 22:09:05 -06001410 comp.num_output_ptr = 0;
1411 comp.max_output_ptr = 0;
1412 comp.output_ptr = NULL;
1413 comp.input = NULL;
1414
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001415 if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1416 {
1417 png_warning(png_ptr, "Empty keyword in iTXt chunk");
1418 return;
1419 }
Glenn Randers-Pehrson73d57cb2002-03-25 18:49:08 -06001420 if (lang == NULL || (lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001421 {
1422 png_warning(png_ptr, "Empty language field in iTXt chunk");
Glenn Randers-Pehrson73d57cb2002-03-25 18:49:08 -06001423 new_lang = NULL;
Glenn Randers-Pehrson5b5dcf82004-07-17 22:45:44 -05001424 lang_len = 0;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001425 }
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001426
Glenn Randers-Pehrson73d57cb2002-03-25 18:49:08 -06001427 if (lang_key == NULL)
1428 lang_key_len = 0;
1429 else
1430 lang_key_len = png_strlen(lang_key);
1431
1432 if (text == NULL)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001433 text_len = 0;
Glenn Randers-Pehrson73d57cb2002-03-25 18:49:08 -06001434 else
1435 text_len = png_strlen(text);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001436
1437 /* compute the compressed data; do it now for the length */
Glenn Randers-Pehrson6942d532000-05-01 09:31:54 -05001438 text_len = png_text_compress(png_ptr, text, text_len, compression-2,
1439 &comp);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001440
Glenn Randers-Pehrson73d57cb2002-03-25 18:49:08 -06001441
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001442 /* make sure we include the compression flag, the compression byte,
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001443 * and the NULs after the key, lang, and lang_key parts */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001444
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001445 png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
1446 (png_uint_32)(
1447 5 /* comp byte, comp flag, terminators for key, lang and lang_key */
1448 + key_len
1449 + lang_len
1450 + lang_key_len
1451 + text_len));
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001452
1453 /*
1454 * We leave it to the application to meet PNG-1.0 requirements on the
1455 * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1456 * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1457 * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1458 */
1459 png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001460
1461 /* set the compression flag */
1462 if (compression == PNG_ITXT_COMPRESSION_NONE || \
1463 compression == PNG_TEXT_COMPRESSION_NONE)
1464 cbuf[0] = 0;
1465 else /* compression == PNG_ITXT_COMPRESSION_zTXt */
1466 cbuf[0] = 1;
1467 /* set the compression method */
1468 cbuf[1] = 0;
1469 png_write_chunk_data(png_ptr, cbuf, 2);
1470
Glenn Randers-Pehrson73d57cb2002-03-25 18:49:08 -06001471 cbuf[0] = 0;
1472 png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf), lang_len + 1);
1473 png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf), lang_key_len + 1);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001474 png_write_compressed_data_out(png_ptr, &comp);
1475
1476 png_write_chunk_end(png_ptr);
1477 png_free(png_ptr, new_key);
Glenn Randers-Pehrson73d57cb2002-03-25 18:49:08 -06001478 if (new_lang)
1479 png_free(png_ptr, new_lang);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001480}
1481#endif
Andreas Dilger47a0c421997-05-16 02:46:07 -05001482
1483#if defined(PNG_WRITE_oFFs_SUPPORTED)
1484/* write the oFFs chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001485void /* PRIVATE */
Glenn Randers-Pehrsonb1828932001-06-23 08:03:17 -05001486png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
Andreas Dilger47a0c421997-05-16 02:46:07 -05001487 int unit_type)
1488{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001489#ifdef PNG_USE_LOCAL_ARRAYS
1490 PNG_oFFs;
1491#endif
Andreas Dilger47a0c421997-05-16 02:46:07 -05001492 png_byte buf[9];
1493
1494 png_debug(1, "in png_write_oFFs\n");
1495 if (unit_type >= PNG_OFFSET_LAST)
1496 png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
1497
Glenn Randers-Pehrsonb1828932001-06-23 08:03:17 -05001498 png_save_int_32(buf, x_offset);
1499 png_save_int_32(buf + 4, y_offset);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001500 buf[8] = (png_byte)unit_type;
1501
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001502 png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001503}
1504#endif
1505
1506#if defined(PNG_WRITE_pCAL_SUPPORTED)
Glenn Randers-Pehrsonff9c9472000-07-11 07:12:36 -05001507/* write the pCAL chunk (described in the PNG extensions document) */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001508void /* PRIVATE */
Andreas Dilger47a0c421997-05-16 02:46:07 -05001509png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
1510 png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
1511{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001512#ifdef PNG_USE_LOCAL_ARRAYS
1513 PNG_pCAL;
1514#endif
Glenn Randers-Pehrson5c6aeb21998-12-29 11:47:59 -06001515 png_size_t purpose_len, units_len, total_len;
Andreas Dilger47a0c421997-05-16 02:46:07 -05001516 png_uint_32p params_len;
1517 png_byte buf[10];
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06001518 png_charp new_purpose;
Andreas Dilger47a0c421997-05-16 02:46:07 -05001519 int i;
1520
1521 png_debug1(1, "in png_write_pCAL (%d parameters)\n", nparams);
1522 if (type >= PNG_EQUATION_LAST)
1523 png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
1524
1525 purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
Glenn Randers-Pehrson8b6a8892001-05-18 04:54:50 -05001526 png_debug1(3, "pCAL purpose length = %d\n", (int)purpose_len);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001527 units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
Glenn Randers-Pehrson8b6a8892001-05-18 04:54:50 -05001528 png_debug1(3, "pCAL units length = %d\n", (int)units_len);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001529 total_len = purpose_len + units_len + 10;
1530
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001531 params_len = (png_uint_32p)png_malloc(png_ptr, (png_uint_32)(nparams
Glenn Randers-Pehrson5fea36f2004-07-28 08:20:44 -05001532 *png_sizeof(png_uint_32)));
Andreas Dilger47a0c421997-05-16 02:46:07 -05001533
1534 /* Find the length of each parameter, making sure we don't count the
1535 null terminator for the last parameter. */
1536 for (i = 0; i < nparams; i++)
1537 {
1538 params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
Glenn Randers-Pehrson4766a242000-07-17 06:17:09 -05001539 png_debug2(3, "pCAL parameter %d length = %lu\n", i, params_len[i]);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001540 total_len += (png_size_t)params_len[i];
1541 }
1542
Glenn Randers-Pehrson8b6a8892001-05-18 04:54:50 -05001543 png_debug1(3, "pCAL total length = %d\n", (int)total_len);
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001544 png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06001545 png_write_chunk_data(png_ptr, (png_bytep)new_purpose, purpose_len);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001546 png_save_int_32(buf, X0);
1547 png_save_int_32(buf + 4, X1);
1548 buf[8] = (png_byte)type;
1549 buf[9] = (png_byte)nparams;
1550 png_write_chunk_data(png_ptr, buf, (png_size_t)10);
1551 png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);
1552
1553 png_free(png_ptr, new_purpose);
1554
1555 for (i = 0; i < nparams; i++)
1556 {
1557 png_write_chunk_data(png_ptr, (png_bytep)params[i],
1558 (png_size_t)params_len[i]);
1559 }
1560
Glenn Randers-Pehrsonc4a2ae61998-01-16 22:06:18 -06001561 png_free(png_ptr, params_len);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001562 png_write_chunk_end(png_ptr);
1563}
1564#endif
1565
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001566#if defined(PNG_WRITE_sCAL_SUPPORTED)
1567/* write the sCAL chunk */
Glenn Randers-Pehrson68ea2432000-04-01 21:10:05 -06001568#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001569void /* PRIVATE */
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001570png_write_sCAL(png_structp png_ptr, int unit, double width,double height)
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001571{
1572#ifdef PNG_USE_LOCAL_ARRAYS
1573 PNG_sCAL;
1574#endif
1575 png_size_t total_len;
1576 char wbuf[32], hbuf[32];
Glenn Randers-Pehrson9c3ab682006-02-20 22:09:05 -06001577 png_byte bunit = (png_byte)unit;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001578
1579 png_debug(1, "in png_write_sCAL\n");
1580
Glenn Randers-Pehrson17218292006-04-20 07:20:46 -05001581 png_sprintf(wbuf, "%12.12e", width);
1582 png_sprintf(hbuf, "%12.12e", height);
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001583 total_len = 1 + png_strlen(wbuf)+1 + png_strlen(hbuf);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001584
Glenn Randers-Pehrson8b6a8892001-05-18 04:54:50 -05001585 png_debug1(3, "sCAL total length = %d\n", (int)total_len);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001586 png_write_chunk_start(png_ptr, (png_bytep)png_sCAL, (png_uint_32)total_len);
Glenn Randers-Pehrson67864af2004-08-28 23:30:07 -05001587 png_write_chunk_data(png_ptr, (png_bytep)&bunit, 1);
Glenn Randers-Pehrson3097f612001-05-07 14:52:45 -05001588 png_write_chunk_data(png_ptr, (png_bytep)wbuf, png_strlen(wbuf)+1);
1589 png_write_chunk_data(png_ptr, (png_bytep)hbuf, png_strlen(hbuf));
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001590
1591 png_write_chunk_end(png_ptr);
1592}
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001593#else
1594#ifdef PNG_FIXED_POINT_SUPPORTED
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001595void /* PRIVATE */
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001596png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001597 png_charp height)
1598{
1599#ifdef PNG_USE_LOCAL_ARRAYS
1600 PNG_sCAL;
1601#endif
1602 png_size_t total_len;
1603 char wbuf[32], hbuf[32];
Glenn Randers-Pehrson67864af2004-08-28 23:30:07 -05001604 png_byte bunit = unit;
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001605
Glenn Randers-Pehrson68ea2432000-04-01 21:10:05 -06001606 png_debug(1, "in png_write_sCAL_s\n");
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001607
Glenn Randers-Pehrson3097f612001-05-07 14:52:45 -05001608 png_strcpy(wbuf,(const char *)width);
1609 png_strcpy(hbuf,(const char *)height);
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001610 total_len = 1 + png_strlen(wbuf)+1 + png_strlen(hbuf);
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001611
1612 png_debug1(3, "sCAL total length = %d\n", total_len);
1613 png_write_chunk_start(png_ptr, (png_bytep)png_sCAL, (png_uint_32)total_len);
Glenn Randers-Pehrson67864af2004-08-28 23:30:07 -05001614 png_write_chunk_data(png_ptr, (png_bytep)&bunit, 1);
Glenn Randers-Pehrson3097f612001-05-07 14:52:45 -05001615 png_write_chunk_data(png_ptr, (png_bytep)wbuf, png_strlen(wbuf)+1);
1616 png_write_chunk_data(png_ptr, (png_bytep)hbuf, png_strlen(hbuf));
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001617
1618 png_write_chunk_end(png_ptr);
1619}
1620#endif
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001621#endif
1622#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001623
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001624#if defined(PNG_WRITE_pHYs_SUPPORTED)
Guy Schalnat0d580581995-07-20 02:43:20 -05001625/* write the pHYs chunk */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001626void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -06001627png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
Guy Schalnat0d580581995-07-20 02:43:20 -05001628 png_uint_32 y_pixels_per_unit,
1629 int unit_type)
1630{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001631#ifdef PNG_USE_LOCAL_ARRAYS
1632 PNG_pHYs;
1633#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001634 png_byte buf[9];
1635
Andreas Dilger47a0c421997-05-16 02:46:07 -05001636 png_debug(1, "in png_write_pHYs\n");
Guy Schalnate5a37791996-06-05 15:50:50 -05001637 if (unit_type >= PNG_RESOLUTION_LAST)
1638 png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
1639
Guy Schalnat0d580581995-07-20 02:43:20 -05001640 png_save_uint_32(buf, x_pixels_per_unit);
1641 png_save_uint_32(buf + 4, y_pixels_per_unit);
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001642 buf[8] = (png_byte)unit_type;
Guy Schalnat0d580581995-07-20 02:43:20 -05001643
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001644 png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
Guy Schalnat0d580581995-07-20 02:43:20 -05001645}
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001646#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001647
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001648#if defined(PNG_WRITE_tIME_SUPPORTED)
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06001649/* Write the tIME chunk. Use either png_convert_from_struct_tm()
1650 * or png_convert_from_time_t(), or fill in the structure yourself.
1651 */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001652void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -06001653png_write_tIME(png_structp png_ptr, png_timep mod_time)
Guy Schalnat0d580581995-07-20 02:43:20 -05001654{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001655#ifdef PNG_USE_LOCAL_ARRAYS
1656 PNG_tIME;
1657#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001658 png_byte buf[7];
1659
Andreas Dilger47a0c421997-05-16 02:46:07 -05001660 png_debug(1, "in png_write_tIME\n");
Guy Schalnate5a37791996-06-05 15:50:50 -05001661 if (mod_time->month > 12 || mod_time->month < 1 ||
1662 mod_time->day > 31 || mod_time->day < 1 ||
1663 mod_time->hour > 23 || mod_time->second > 60)
1664 {
1665 png_warning(png_ptr, "Invalid time specified for tIME chunk");
1666 return;
1667 }
1668
Guy Schalnat0d580581995-07-20 02:43:20 -05001669 png_save_uint_16(buf, mod_time->year);
1670 buf[2] = mod_time->month;
1671 buf[3] = mod_time->day;
1672 buf[4] = mod_time->hour;
1673 buf[5] = mod_time->minute;
1674 buf[6] = mod_time->second;
1675
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001676 png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
Guy Schalnat0d580581995-07-20 02:43:20 -05001677}
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001678#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001679
1680/* initializes the row writing capability of libpng */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001681void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -06001682png_write_start_row(png_structp png_ptr)
Guy Schalnat0d580581995-07-20 02:43:20 -05001683{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001684#ifdef PNG_USE_LOCAL_ARRAYS
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001685 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001686
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001687 /* start of interlace block */
1688 int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001689
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001690 /* offset to next interlace block */
1691 int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001692
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001693 /* start of interlace block in the y direction */
1694 int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001695
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001696 /* offset to next interlace block in the y direction */
1697 int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001698#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001699
Andreas Dilger47a0c421997-05-16 02:46:07 -05001700 png_size_t buf_size;
1701
1702 png_debug(1, "in png_write_start_row\n");
Glenn Randers-Pehrson272489d2004-08-04 06:34:52 -05001703 buf_size = (png_size_t)(PNG_ROWBYTES(
1704 png_ptr->usr_channels*png_ptr->usr_bit_depth,png_ptr->width)+1);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001705
Guy Schalnat0d580581995-07-20 02:43:20 -05001706 /* set up row buffer */
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001707 png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001708 png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
Guy Schalnate5a37791996-06-05 15:50:50 -05001709
1710 /* set up filtering buffer, if using this filter */
1711 if (png_ptr->do_filter & PNG_FILTER_SUB)
Guy Schalnat0d580581995-07-20 02:43:20 -05001712 {
Andreas Dilger47a0c421997-05-16 02:46:07 -05001713 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001714 (png_ptr->rowbytes + 1));
Andreas Dilger47a0c421997-05-16 02:46:07 -05001715 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
Guy Schalnate5a37791996-06-05 15:50:50 -05001716 }
1717
Andreas Dilger47a0c421997-05-16 02:46:07 -05001718 /* We only need to keep the previous row if we are using one of these. */
Guy Schalnate5a37791996-06-05 15:50:50 -05001719 if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
1720 {
1721 /* set up previous row buffer */
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001722 png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
Andreas Dilger47a0c421997-05-16 02:46:07 -05001723 png_memset(png_ptr->prev_row, 0, buf_size);
Guy Schalnate5a37791996-06-05 15:50:50 -05001724
1725 if (png_ptr->do_filter & PNG_FILTER_UP)
1726 {
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001727 png_ptr->up_row = (png_bytep )png_malloc(png_ptr,
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001728 (png_ptr->rowbytes + 1));
Andreas Dilger47a0c421997-05-16 02:46:07 -05001729 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
Guy Schalnate5a37791996-06-05 15:50:50 -05001730 }
1731
1732 if (png_ptr->do_filter & PNG_FILTER_AVG)
1733 {
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001734 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1735 (png_ptr->rowbytes + 1));
Andreas Dilger47a0c421997-05-16 02:46:07 -05001736 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
Guy Schalnate5a37791996-06-05 15:50:50 -05001737 }
1738
1739 if (png_ptr->do_filter & PNG_FILTER_PAETH)
1740 {
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001741 png_ptr->paeth_row = (png_bytep )png_malloc(png_ptr,
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06001742 (png_ptr->rowbytes + 1));
Andreas Dilger47a0c421997-05-16 02:46:07 -05001743 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
Guy Schalnate5a37791996-06-05 15:50:50 -05001744 }
Guy Schalnat0d580581995-07-20 02:43:20 -05001745 }
1746
Glenn Randers-Pehrson46f61e21998-01-30 21:45:12 -06001747#ifdef PNG_WRITE_INTERLACING_SUPPORTED
Guy Schalnat0d580581995-07-20 02:43:20 -05001748 /* if interlaced, we need to set up width and height of pass */
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001749 if (png_ptr->interlaced)
Guy Schalnat0d580581995-07-20 02:43:20 -05001750 {
1751 if (!(png_ptr->transformations & PNG_INTERLACE))
1752 {
1753 png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
1754 png_pass_ystart[0]) / png_pass_yinc[0];
Andreas Dilger47a0c421997-05-16 02:46:07 -05001755 png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
1756 png_pass_start[0]) / png_pass_inc[0];
Guy Schalnat0d580581995-07-20 02:43:20 -05001757 }
1758 else
1759 {
1760 png_ptr->num_rows = png_ptr->height;
1761 png_ptr->usr_width = png_ptr->width;
1762 }
1763 }
1764 else
Glenn Randers-Pehrson46f61e21998-01-30 21:45:12 -06001765#endif
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001766 {
Guy Schalnat0d580581995-07-20 02:43:20 -05001767 png_ptr->num_rows = png_ptr->height;
1768 png_ptr->usr_width = png_ptr->width;
1769 }
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001770 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1771 png_ptr->zstream.next_out = png_ptr->zbuf;
Guy Schalnat0d580581995-07-20 02:43:20 -05001772}
1773
Andreas Dilger47a0c421997-05-16 02:46:07 -05001774/* Internal use only. Called when finished processing a row of data. */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001775void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -06001776png_write_finish_row(png_structp png_ptr)
Guy Schalnat0d580581995-07-20 02:43:20 -05001777{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001778#ifdef PNG_USE_LOCAL_ARRAYS
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001779 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001780
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001781 /* start of interlace block */
1782 int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001783
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001784 /* offset to next interlace block */
1785 int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001786
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001787 /* start of interlace block in the y direction */
1788 int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001789
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001790 /* offset to next interlace block in the y direction */
1791 int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001792#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001793
Guy Schalnat0d580581995-07-20 02:43:20 -05001794 int ret;
1795
Andreas Dilger47a0c421997-05-16 02:46:07 -05001796 png_debug(1, "in png_write_finish_row\n");
Guy Schalnat0d580581995-07-20 02:43:20 -05001797 /* next row */
1798 png_ptr->row_number++;
Guy Schalnatc21f90c1996-06-17 16:24:45 -05001799
Guy Schalnat0d580581995-07-20 02:43:20 -05001800 /* see if we are done */
Guy Schalnat6d764711995-12-19 03:22:19 -06001801 if (png_ptr->row_number < png_ptr->num_rows)
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001802 return;
Guy Schalnat0d580581995-07-20 02:43:20 -05001803
Glenn Randers-Pehrson46f61e21998-01-30 21:45:12 -06001804#ifdef PNG_WRITE_INTERLACING_SUPPORTED
Guy Schalnat0d580581995-07-20 02:43:20 -05001805 /* if interlaced, go to next pass */
1806 if (png_ptr->interlaced)
1807 {
1808 png_ptr->row_number = 0;
1809 if (png_ptr->transformations & PNG_INTERLACE)
1810 {
1811 png_ptr->pass++;
1812 }
1813 else
1814 {
1815 /* loop until we find a non-zero width or height pass */
1816 do
1817 {
1818 png_ptr->pass++;
1819 if (png_ptr->pass >= 7)
1820 break;
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001821 png_ptr->usr_width = (png_ptr->width +
Guy Schalnat0d580581995-07-20 02:43:20 -05001822 png_pass_inc[png_ptr->pass] - 1 -
1823 png_pass_start[png_ptr->pass]) /
1824 png_pass_inc[png_ptr->pass];
1825 png_ptr->num_rows = (png_ptr->height +
1826 png_pass_yinc[png_ptr->pass] - 1 -
1827 png_pass_ystart[png_ptr->pass]) /
1828 png_pass_yinc[png_ptr->pass];
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001829 if (png_ptr->transformations & PNG_INTERLACE)
1830 break;
Guy Schalnat0d580581995-07-20 02:43:20 -05001831 } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
1832
1833 }
1834
Guy Schalnate5a37791996-06-05 15:50:50 -05001835 /* reset the row above the image for the next pass */
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001836 if (png_ptr->pass < 7)
Guy Schalnatc21f90c1996-06-17 16:24:45 -05001837 {
Andreas Dilger47a0c421997-05-16 02:46:07 -05001838 if (png_ptr->prev_row != NULL)
Glenn Randers-Pehrson5c6aeb21998-12-29 11:47:59 -06001839 png_memset(png_ptr->prev_row, 0,
Glenn Randers-Pehrson272489d2004-08-04 06:34:52 -05001840 (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
1841 png_ptr->usr_bit_depth,png_ptr->width))+1);
Guy Schalnat0d580581995-07-20 02:43:20 -05001842 return;
Guy Schalnatc21f90c1996-06-17 16:24:45 -05001843 }
Guy Schalnat0d580581995-07-20 02:43:20 -05001844 }
Glenn Randers-Pehrson46f61e21998-01-30 21:45:12 -06001845#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001846
1847 /* if we get here, we've just written the last row, so we need
1848 to flush the compressor */
1849 do
1850 {
1851 /* tell the compressor we are done */
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001852 ret = deflate(&png_ptr->zstream, Z_FINISH);
Guy Schalnat0d580581995-07-20 02:43:20 -05001853 /* check for an error */
Glenn Randers-Pehrson104622b2000-05-29 08:58:03 -05001854 if (ret == Z_OK)
1855 {
1856 /* check to see if we need more room */
1857 if (!(png_ptr->zstream.avail_out))
1858 {
1859 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
1860 png_ptr->zstream.next_out = png_ptr->zbuf;
1861 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1862 }
1863 }
1864 else if (ret != Z_STREAM_END)
Guy Schalnat0d580581995-07-20 02:43:20 -05001865 {
Andreas Dilger47a0c421997-05-16 02:46:07 -05001866 if (png_ptr->zstream.msg != NULL)
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001867 png_error(png_ptr, png_ptr->zstream.msg);
Guy Schalnat0d580581995-07-20 02:43:20 -05001868 else
Guy Schalnat6d764711995-12-19 03:22:19 -06001869 png_error(png_ptr, "zlib error");
Guy Schalnat0d580581995-07-20 02:43:20 -05001870 }
Guy Schalnat0d580581995-07-20 02:43:20 -05001871 } while (ret != Z_STREAM_END);
1872
1873 /* write any extra space */
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001874 if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
Guy Schalnat0d580581995-07-20 02:43:20 -05001875 {
1876 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001877 png_ptr->zstream.avail_out);
Guy Schalnat0d580581995-07-20 02:43:20 -05001878 }
1879
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06001880 deflateReset(&png_ptr->zstream);
Glenn Randers-Pehrson878b31e2004-11-12 22:04:56 -06001881 png_ptr->zstream.data_type = Z_BINARY;
Guy Schalnat0d580581995-07-20 02:43:20 -05001882}
1883
Guy Schalnat51f0eb41995-09-26 05:22:39 -05001884#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06001885/* Pick out the correct pixels for the interlace pass.
1886 * The basic idea here is to go through the row with a source
1887 * pointer and a destination pointer (sp and dp), and copy the
1888 * correct pixels for the pass. As the row gets compacted,
1889 * sp will always be >= dp, so we should never overwrite anything.
1890 * See the default: case for the easiest code to understand.
1891 */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05001892void /* PRIVATE */
Guy Schalnat6d764711995-12-19 03:22:19 -06001893png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
Guy Schalnat0d580581995-07-20 02:43:20 -05001894{
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001895#ifdef PNG_USE_LOCAL_ARRAYS
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001896 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001897
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001898 /* start of interlace block */
1899 int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001900
Glenn Randers-Pehrson5379b241999-11-27 10:22:33 -06001901 /* offset to next interlace block */
1902 int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
Glenn Randers-Pehrson074af5e1999-11-28 23:32:18 -06001903#endif
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06001904
Andreas Dilger47a0c421997-05-16 02:46:07 -05001905 png_debug(1, "in png_do_write_interlace\n");
Guy Schalnat0d580581995-07-20 02:43:20 -05001906 /* we don't have to do anything on the last pass (6) */
Andreas Dilger47a0c421997-05-16 02:46:07 -05001907#if defined(PNG_USELESS_TESTS_SUPPORTED)
1908 if (row != NULL && row_info != NULL && pass < 6)
1909#else
1910 if (pass < 6)
1911#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05001912 {
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05001913 /* each pixel depth is handled separately */
Guy Schalnat0d580581995-07-20 02:43:20 -05001914 switch (row_info->pixel_depth)
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001915 {
Guy Schalnat0d580581995-07-20 02:43:20 -05001916 case 1:
1917 {
Guy Schalnat6d764711995-12-19 03:22:19 -06001918 png_bytep sp;
1919 png_bytep dp;
Guy Schalnat0d580581995-07-20 02:43:20 -05001920 int shift;
1921 int d;
1922 int value;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05001923 png_uint_32 i;
1924 png_uint_32 row_width = row_info->width;
Guy Schalnat0d580581995-07-20 02:43:20 -05001925
1926 dp = row;
1927 d = 0;
1928 shift = 7;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05001929 for (i = png_pass_start[pass]; i < row_width;
Guy Schalnat0d580581995-07-20 02:43:20 -05001930 i += png_pass_inc[pass])
1931 {
1932 sp = row + (png_size_t)(i >> 3);
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001933 value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
Guy Schalnat0d580581995-07-20 02:43:20 -05001934 d |= (value << shift);
1935
1936 if (shift == 0)
1937 {
1938 shift = 7;
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001939 *dp++ = (png_byte)d;
Guy Schalnat0d580581995-07-20 02:43:20 -05001940 d = 0;
1941 }
1942 else
1943 shift--;
1944
1945 }
1946 if (shift != 7)
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001947 *dp = (png_byte)d;
Guy Schalnat0d580581995-07-20 02:43:20 -05001948 break;
1949 }
1950 case 2:
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001951 {
Guy Schalnat6d764711995-12-19 03:22:19 -06001952 png_bytep sp;
1953 png_bytep dp;
Guy Schalnat0d580581995-07-20 02:43:20 -05001954 int shift;
1955 int d;
1956 int value;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05001957 png_uint_32 i;
1958 png_uint_32 row_width = row_info->width;
Guy Schalnat0d580581995-07-20 02:43:20 -05001959
1960 dp = row;
1961 shift = 6;
1962 d = 0;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05001963 for (i = png_pass_start[pass]; i < row_width;
Guy Schalnat0d580581995-07-20 02:43:20 -05001964 i += png_pass_inc[pass])
1965 {
1966 sp = row + (png_size_t)(i >> 2);
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06001967 value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
Guy Schalnat0d580581995-07-20 02:43:20 -05001968 d |= (value << shift);
1969
1970 if (shift == 0)
1971 {
1972 shift = 6;
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001973 *dp++ = (png_byte)d;
Guy Schalnat0d580581995-07-20 02:43:20 -05001974 d = 0;
1975 }
1976 else
1977 shift -= 2;
1978 }
1979 if (shift != 6)
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001980 *dp = (png_byte)d;
Guy Schalnat0d580581995-07-20 02:43:20 -05001981 break;
1982 }
1983 case 4:
1984 {
Guy Schalnat6d764711995-12-19 03:22:19 -06001985 png_bytep sp;
1986 png_bytep dp;
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06001987 int shift;
Guy Schalnat0d580581995-07-20 02:43:20 -05001988 int d;
1989 int value;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05001990 png_uint_32 i;
1991 png_uint_32 row_width = row_info->width;
Guy Schalnat0d580581995-07-20 02:43:20 -05001992
1993 dp = row;
1994 shift = 4;
1995 d = 0;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05001996 for (i = png_pass_start[pass]; i < row_width;
Guy Schalnat0d580581995-07-20 02:43:20 -05001997 i += png_pass_inc[pass])
1998 {
1999 sp = row + (png_size_t)(i >> 1);
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06002000 value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
Guy Schalnat0d580581995-07-20 02:43:20 -05002001 d |= (value << shift);
2002
2003 if (shift == 0)
2004 {
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06002005 shift = 4;
2006 *dp++ = (png_byte)d;
Guy Schalnat0d580581995-07-20 02:43:20 -05002007 d = 0;
2008 }
2009 else
2010 shift -= 4;
2011 }
2012 if (shift != 4)
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06002013 *dp = (png_byte)d;
Guy Schalnat0d580581995-07-20 02:43:20 -05002014 break;
2015 }
2016 default:
2017 {
Guy Schalnat6d764711995-12-19 03:22:19 -06002018 png_bytep sp;
2019 png_bytep dp;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002020 png_uint_32 i;
2021 png_uint_32 row_width = row_info->width;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002022 png_size_t pixel_bytes;
Guy Schalnat0d580581995-07-20 02:43:20 -05002023
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06002024 /* start at the beginning */
Guy Schalnat0d580581995-07-20 02:43:20 -05002025 dp = row;
2026 /* find out how many bytes each pixel takes up */
2027 pixel_bytes = (row_info->pixel_depth >> 3);
2028 /* loop through the row, only looking at the pixels that
2029 matter */
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002030 for (i = png_pass_start[pass]; i < row_width;
Guy Schalnat0d580581995-07-20 02:43:20 -05002031 i += png_pass_inc[pass])
2032 {
2033 /* find out where the original pixel is */
Glenn Randers-Pehrsona357b991998-02-08 20:56:40 -06002034 sp = row + (png_size_t)i * pixel_bytes;
Guy Schalnat0d580581995-07-20 02:43:20 -05002035 /* move the pixel */
2036 if (dp != sp)
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002037 png_memcpy(dp, sp, pixel_bytes);
Guy Schalnat0d580581995-07-20 02:43:20 -05002038 /* next pixel */
2039 dp += pixel_bytes;
2040 }
Guy Schalnatb2e01bd1996-01-26 01:38:47 -06002041 break;
Guy Schalnat0d580581995-07-20 02:43:20 -05002042 }
2043 }
2044 /* set new row width */
2045 row_info->width = (row_info->width +
2046 png_pass_inc[pass] - 1 -
2047 png_pass_start[pass]) /
2048 png_pass_inc[pass];
Glenn Randers-Pehrson272489d2004-08-04 06:34:52 -05002049 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
2050 row_info->width);
Guy Schalnat0d580581995-07-20 02:43:20 -05002051 }
2052}
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002053#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05002054
Andreas Dilger47a0c421997-05-16 02:46:07 -05002055/* This filters the row, chooses which filter to use, if it has not already
2056 * been specified by the application, and then writes the row out with the
Glenn Randers-Pehrsonb6ce43d1998-01-01 07:13:13 -06002057 * chosen filter.
2058 */
Glenn Randers-Pehrson78067772004-11-02 21:49:39 -06002059#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002060#define PNG_HISHIFT 10
Glenn Randers-Pehrsonea3bcd71998-03-07 14:33:00 -06002061#define PNG_LOMASK ((png_uint_32)0xffffL)
2062#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05002063void /* PRIVATE */
Guy Schalnate5a37791996-06-05 15:50:50 -05002064png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
Guy Schalnat0d580581995-07-20 02:43:20 -05002065{
Guy Schalnate5a37791996-06-05 15:50:50 -05002066 png_bytep prev_row, best_row, row_buf;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002067 png_uint_32 mins, bpp;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002068 png_byte filter_to_do = png_ptr->do_filter;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002069 png_uint_32 row_bytes = row_info->rowbytes;
2070#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2071 int num_p_filters = (int)png_ptr->num_prev_filters;
2072#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05002073
Andreas Dilger47a0c421997-05-16 02:46:07 -05002074 png_debug(1, "in png_write_find_filter\n");
Guy Schalnat0d580581995-07-20 02:43:20 -05002075 /* find out how many bytes offset each pixel is */
Glenn Randers-Pehrson272489d2004-08-04 06:34:52 -05002076 bpp = (row_info->pixel_depth + 7) >> 3;
Guy Schalnate5a37791996-06-05 15:50:50 -05002077
2078 prev_row = png_ptr->prev_row;
2079 best_row = row_buf = png_ptr->row_buf;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002080 mins = PNG_MAXSUM;
Guy Schalnat0d580581995-07-20 02:43:20 -05002081
Andreas Dilger47a0c421997-05-16 02:46:07 -05002082 /* The prediction method we use is to find which method provides the
2083 * smallest value when summing the absolute values of the distances
Glenn Randers-Pehrson8686fff1998-05-21 09:27:50 -05002084 * from zero, using anything >= 128 as negative numbers. This is known
Andreas Dilger47a0c421997-05-16 02:46:07 -05002085 * as the "minimum sum of absolute differences" heuristic. Other
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002086 * heuristics are the "weighted minimum sum of absolute differences"
Andreas Dilger47a0c421997-05-16 02:46:07 -05002087 * (experimental and can in theory improve compression), and the "zlib
Glenn Randers-Pehrsonf7d1a171998-06-06 15:31:35 -05002088 * predictive" method (not implemented yet), which does test compressions
2089 * of lines using different filter methods, and then chooses the
2090 * (series of) filter(s) that give minimum compressed data size (VERY
Andreas Dilger47a0c421997-05-16 02:46:07 -05002091 * computationally expensive).
Glenn Randers-Pehrsonf7d1a171998-06-06 15:31:35 -05002092 *
2093 * GRR 980525: consider also
2094 * (1) minimum sum of absolute differences from running average (i.e.,
2095 * keep running sum of non-absolute differences & count of bytes)
2096 * [track dispersion, too? restart average if dispersion too large?]
2097 * (1b) minimum sum of absolute differences from sliding average, probably
2098 * with window size <= deflate window (usually 32K)
2099 * (2) minimum sum of squared differences from zero or running average
2100 * (i.e., ~ root-mean-square approach)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002101 */
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002102
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002103
Guy Schalnate5a37791996-06-05 15:50:50 -05002104 /* We don't need to test the 'no filter' case if this is the only filter
Andreas Dilger47a0c421997-05-16 02:46:07 -05002105 * that has been chosen, as it doesn't actually do anything to the data.
2106 */
Glenn Randers-Pehrson61c32d92000-02-04 23:40:16 -06002107 if ((filter_to_do & PNG_FILTER_NONE) &&
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002108 filter_to_do != PNG_FILTER_NONE)
Guy Schalnat0d580581995-07-20 02:43:20 -05002109 {
Guy Schalnate5a37791996-06-05 15:50:50 -05002110 png_bytep rp;
2111 png_uint_32 sum = 0;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002112 png_uint_32 i;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002113 int v;
Guy Schalnat0d580581995-07-20 02:43:20 -05002114
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002115 for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
Guy Schalnate5a37791996-06-05 15:50:50 -05002116 {
2117 v = *rp;
2118 sum += (v < 128) ? v : 256 - v;
2119 }
Andreas Dilger47a0c421997-05-16 02:46:07 -05002120
2121#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2122 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2123 {
2124 png_uint_32 sumhi, sumlo;
Glenn Randers-Pehrsond0dce401998-05-09 10:02:29 -05002125 int j;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002126 sumlo = sum & PNG_LOMASK;
2127 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
2128
2129 /* Reduce the sum if we match any of the previous rows */
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002130 for (j = 0; j < num_p_filters; j++)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002131 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002132 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002133 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002134 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002135 PNG_WEIGHT_SHIFT;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002136 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002137 PNG_WEIGHT_SHIFT;
2138 }
2139 }
2140
2141 /* Factor in the cost of this filter (this is here for completeness,
2142 * but it makes no sense to have a "cost" for the NONE filter, as
2143 * it has the minimum possible computational cost - none).
2144 */
2145 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2146 PNG_COST_SHIFT;
2147 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2148 PNG_COST_SHIFT;
2149
2150 if (sumhi > PNG_HIMASK)
2151 sum = PNG_MAXSUM;
2152 else
2153 sum = (sumhi << PNG_HISHIFT) + sumlo;
2154 }
2155#endif
Guy Schalnate5a37791996-06-05 15:50:50 -05002156 mins = sum;
Guy Schalnat0d580581995-07-20 02:43:20 -05002157 }
2158
Guy Schalnate5a37791996-06-05 15:50:50 -05002159 /* sub filter */
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002160 if (filter_to_do == PNG_FILTER_SUB)
2161 /* it's the only filter so no testing is needed */
2162 {
2163 png_bytep rp, lp, dp;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002164 png_uint_32 i;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002165 for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2166 i++, rp++, dp++)
2167 {
2168 *dp = *rp;
2169 }
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002170 for (lp = row_buf + 1; i < row_bytes;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002171 i++, rp++, lp++, dp++)
2172 {
2173 *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2174 }
2175 best_row = png_ptr->sub_row;
2176 }
2177
2178 else if (filter_to_do & PNG_FILTER_SUB)
Guy Schalnat0d580581995-07-20 02:43:20 -05002179 {
Guy Schalnate5a37791996-06-05 15:50:50 -05002180 png_bytep rp, dp, lp;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002181 png_uint_32 sum = 0, lmins = mins;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002182 png_uint_32 i;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002183 int v;
2184
2185#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002186 /* We temporarily increase the "minimum sum" by the factor we
Andreas Dilger47a0c421997-05-16 02:46:07 -05002187 * would reduce the sum of this filter, so that we can do the
2188 * early exit comparison without scaling the sum each time.
2189 */
2190 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2191 {
Glenn Randers-Pehrsond0dce401998-05-09 10:02:29 -05002192 int j;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002193 png_uint_32 lmhi, lmlo;
2194 lmlo = lmins & PNG_LOMASK;
2195 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2196
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002197 for (j = 0; j < num_p_filters; j++)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002198 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002199 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002200 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002201 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002202 PNG_WEIGHT_SHIFT;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002203 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002204 PNG_WEIGHT_SHIFT;
2205 }
2206 }
2207
2208 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2209 PNG_COST_SHIFT;
2210 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2211 PNG_COST_SHIFT;
2212
2213 if (lmhi > PNG_HIMASK)
2214 lmins = PNG_MAXSUM;
2215 else
2216 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2217 }
2218#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05002219
Guy Schalnate5a37791996-06-05 15:50:50 -05002220 for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2221 i++, rp++, dp++)
2222 {
2223 v = *dp = *rp;
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002224
Guy Schalnate5a37791996-06-05 15:50:50 -05002225 sum += (v < 128) ? v : 256 - v;
2226 }
Glenn Randers-Pehrson5b5dcf82004-07-17 22:45:44 -05002227 for (lp = row_buf + 1; i < row_bytes;
Glenn Randers-Pehrson0f881d61998-02-07 10:20:57 -06002228 i++, rp++, lp++, dp++)
Guy Schalnate5a37791996-06-05 15:50:50 -05002229 {
2230 v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002231
Guy Schalnate5a37791996-06-05 15:50:50 -05002232 sum += (v < 128) ? v : 256 - v;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002233
2234 if (sum > lmins) /* We are already worse, don't continue. */
2235 break;
Guy Schalnate5a37791996-06-05 15:50:50 -05002236 }
Andreas Dilger47a0c421997-05-16 02:46:07 -05002237
2238#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2239 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2240 {
Glenn Randers-Pehrsond0dce401998-05-09 10:02:29 -05002241 int j;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002242 png_uint_32 sumhi, sumlo;
2243 sumlo = sum & PNG_LOMASK;
2244 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2245
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002246 for (j = 0; j < num_p_filters; j++)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002247 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002248 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002249 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002250 sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002251 PNG_WEIGHT_SHIFT;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002252 sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002253 PNG_WEIGHT_SHIFT;
2254 }
2255 }
2256
2257 sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2258 PNG_COST_SHIFT;
2259 sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2260 PNG_COST_SHIFT;
2261
2262 if (sumhi > PNG_HIMASK)
2263 sum = PNG_MAXSUM;
2264 else
2265 sum = (sumhi << PNG_HISHIFT) + sumlo;
2266 }
2267#endif
2268
Guy Schalnate5a37791996-06-05 15:50:50 -05002269 if (sum < mins)
2270 {
2271 mins = sum;
2272 best_row = png_ptr->sub_row;
2273 }
Guy Schalnat0d580581995-07-20 02:43:20 -05002274 }
2275
Guy Schalnate5a37791996-06-05 15:50:50 -05002276 /* up filter */
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002277 if (filter_to_do == PNG_FILTER_UP)
2278 {
2279 png_bytep rp, dp, pp;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002280 png_uint_32 i;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002281
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002282 for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002283 pp = prev_row + 1; i < row_bytes;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002284 i++, rp++, pp++, dp++)
2285 {
2286 *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
2287 }
2288 best_row = png_ptr->up_row;
2289 }
2290
2291 else if (filter_to_do & PNG_FILTER_UP)
Guy Schalnat0d580581995-07-20 02:43:20 -05002292 {
Guy Schalnate5a37791996-06-05 15:50:50 -05002293 png_bytep rp, dp, pp;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002294 png_uint_32 sum = 0, lmins = mins;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002295 png_uint_32 i;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002296 int v;
2297
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002298
Andreas Dilger47a0c421997-05-16 02:46:07 -05002299#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2300 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2301 {
Glenn Randers-Pehrsond0dce401998-05-09 10:02:29 -05002302 int j;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002303 png_uint_32 lmhi, lmlo;
2304 lmlo = lmins & PNG_LOMASK;
2305 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2306
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002307 for (j = 0; j < num_p_filters; j++)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002308 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002309 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002310 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002311 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002312 PNG_WEIGHT_SHIFT;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002313 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002314 PNG_WEIGHT_SHIFT;
2315 }
2316 }
2317
2318 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2319 PNG_COST_SHIFT;
2320 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2321 PNG_COST_SHIFT;
2322
2323 if (lmhi > PNG_HIMASK)
2324 lmins = PNG_MAXSUM;
2325 else
2326 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2327 }
2328#endif
Guy Schalnate5a37791996-06-05 15:50:50 -05002329
2330 for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002331 pp = prev_row + 1; i < row_bytes; i++)
Guy Schalnate5a37791996-06-05 15:50:50 -05002332 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002333 v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
Guy Schalnate5a37791996-06-05 15:50:50 -05002334
2335 sum += (v < 128) ? v : 256 - v;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002336
2337 if (sum > lmins) /* We are already worse, don't continue. */
2338 break;
Guy Schalnate5a37791996-06-05 15:50:50 -05002339 }
Andreas Dilger47a0c421997-05-16 02:46:07 -05002340
2341#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2342 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2343 {
Glenn Randers-Pehrsond0dce401998-05-09 10:02:29 -05002344 int j;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002345 png_uint_32 sumhi, sumlo;
2346 sumlo = sum & PNG_LOMASK;
2347 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2348
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002349 for (j = 0; j < num_p_filters; j++)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002350 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002351 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002352 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002353 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002354 PNG_WEIGHT_SHIFT;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002355 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002356 PNG_WEIGHT_SHIFT;
2357 }
2358 }
2359
2360 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2361 PNG_COST_SHIFT;
2362 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2363 PNG_COST_SHIFT;
2364
2365 if (sumhi > PNG_HIMASK)
2366 sum = PNG_MAXSUM;
2367 else
2368 sum = (sumhi << PNG_HISHIFT) + sumlo;
2369 }
2370#endif
2371
Guy Schalnate5a37791996-06-05 15:50:50 -05002372 if (sum < mins)
2373 {
2374 mins = sum;
2375 best_row = png_ptr->up_row;
2376 }
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002377 }
2378
Guy Schalnate5a37791996-06-05 15:50:50 -05002379 /* avg filter */
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002380 if (filter_to_do == PNG_FILTER_AVG)
2381 {
2382 png_bytep rp, dp, pp, lp;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002383 png_uint_32 i;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002384 for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002385 pp = prev_row + 1; i < bpp; i++)
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002386 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002387 *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002388 }
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002389 for (lp = row_buf + 1; i < row_bytes; i++)
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002390 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002391 *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
2392 & 0xff);
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002393 }
2394 best_row = png_ptr->avg_row;
2395 }
2396
2397 else if (filter_to_do & PNG_FILTER_AVG)
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002398 {
Guy Schalnate5a37791996-06-05 15:50:50 -05002399 png_bytep rp, dp, pp, lp;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002400 png_uint_32 sum = 0, lmins = mins;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002401 png_uint_32 i;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002402 int v;
2403
2404#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2405 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2406 {
Glenn Randers-Pehrsond0dce401998-05-09 10:02:29 -05002407 int j;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002408 png_uint_32 lmhi, lmlo;
2409 lmlo = lmins & PNG_LOMASK;
2410 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2411
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002412 for (j = 0; j < num_p_filters; j++)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002413 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002414 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002415 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002416 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002417 PNG_WEIGHT_SHIFT;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002418 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002419 PNG_WEIGHT_SHIFT;
2420 }
2421 }
2422
2423 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2424 PNG_COST_SHIFT;
2425 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2426 PNG_COST_SHIFT;
2427
2428 if (lmhi > PNG_HIMASK)
2429 lmins = PNG_MAXSUM;
2430 else
2431 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2432 }
2433#endif
Guy Schalnate5a37791996-06-05 15:50:50 -05002434
2435 for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002436 pp = prev_row + 1; i < bpp; i++)
Guy Schalnate5a37791996-06-05 15:50:50 -05002437 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002438 v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
Guy Schalnate5a37791996-06-05 15:50:50 -05002439
2440 sum += (v < 128) ? v : 256 - v;
2441 }
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002442 for (lp = row_buf + 1; i < row_bytes; i++)
Guy Schalnate5a37791996-06-05 15:50:50 -05002443 {
Glenn Randers-Pehrson5c6aeb21998-12-29 11:47:59 -06002444 v = *dp++ =
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002445 (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
Guy Schalnate5a37791996-06-05 15:50:50 -05002446
2447 sum += (v < 128) ? v : 256 - v;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002448
2449 if (sum > lmins) /* We are already worse, don't continue. */
2450 break;
Guy Schalnate5a37791996-06-05 15:50:50 -05002451 }
Andreas Dilger47a0c421997-05-16 02:46:07 -05002452
2453#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2454 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2455 {
Glenn Randers-Pehrsond0dce401998-05-09 10:02:29 -05002456 int j;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002457 png_uint_32 sumhi, sumlo;
2458 sumlo = sum & PNG_LOMASK;
2459 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2460
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002461 for (j = 0; j < num_p_filters; j++)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002462 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002463 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002464 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002465 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002466 PNG_WEIGHT_SHIFT;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002467 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002468 PNG_WEIGHT_SHIFT;
2469 }
2470 }
2471
2472 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2473 PNG_COST_SHIFT;
2474 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2475 PNG_COST_SHIFT;
2476
2477 if (sumhi > PNG_HIMASK)
2478 sum = PNG_MAXSUM;
2479 else
2480 sum = (sumhi << PNG_HISHIFT) + sumlo;
2481 }
2482#endif
2483
Guy Schalnate5a37791996-06-05 15:50:50 -05002484 if (sum < mins)
2485 {
2486 mins = sum;
2487 best_row = png_ptr->avg_row;
2488 }
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002489 }
2490
Andreas Dilger47a0c421997-05-16 02:46:07 -05002491 /* Paeth filter */
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002492 if (filter_to_do == PNG_FILTER_PAETH)
2493 {
2494 png_bytep rp, dp, pp, cp, lp;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002495 png_uint_32 i;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002496 for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002497 pp = prev_row + 1; i < bpp; i++)
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002498 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002499 *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002500 }
2501
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002502 for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002503 {
2504 int a, b, c, pa, pb, pc, p;
2505
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002506 b = *pp++;
2507 c = *cp++;
2508 a = *lp++;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002509
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002510 p = b - c;
2511 pc = a - c;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002512
2513#ifdef PNG_USE_ABS
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002514 pa = abs(p);
2515 pb = abs(pc);
2516 pc = abs(p + pc);
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002517#else
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002518 pa = p < 0 ? -p : p;
2519 pb = pc < 0 ? -pc : pc;
2520 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002521#endif
2522
2523 p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2524
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002525 *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002526 }
2527 best_row = png_ptr->paeth_row;
2528 }
2529
2530 else if (filter_to_do & PNG_FILTER_PAETH)
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002531 {
Guy Schalnate5a37791996-06-05 15:50:50 -05002532 png_bytep rp, dp, pp, cp, lp;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002533 png_uint_32 sum = 0, lmins = mins;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002534 png_uint_32 i;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002535 int v;
2536
2537#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2538 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2539 {
Glenn Randers-Pehrsond0dce401998-05-09 10:02:29 -05002540 int j;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002541 png_uint_32 lmhi, lmlo;
2542 lmlo = lmins & PNG_LOMASK;
2543 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2544
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002545 for (j = 0; j < num_p_filters; j++)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002546 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002547 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002548 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002549 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002550 PNG_WEIGHT_SHIFT;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002551 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002552 PNG_WEIGHT_SHIFT;
2553 }
2554 }
2555
2556 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2557 PNG_COST_SHIFT;
2558 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2559 PNG_COST_SHIFT;
2560
2561 if (lmhi > PNG_HIMASK)
2562 lmins = PNG_MAXSUM;
2563 else
2564 lmins = (lmhi << PNG_HISHIFT) + lmlo;
2565 }
2566#endif
Guy Schalnate5a37791996-06-05 15:50:50 -05002567
2568 for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002569 pp = prev_row + 1; i < bpp; i++)
Guy Schalnate5a37791996-06-05 15:50:50 -05002570 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002571 v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
Guy Schalnate5a37791996-06-05 15:50:50 -05002572
2573 sum += (v < 128) ? v : 256 - v;
2574 }
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002575
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002576 for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
Guy Schalnate5a37791996-06-05 15:50:50 -05002577 {
2578 int a, b, c, pa, pb, pc, p;
2579
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002580 b = *pp++;
2581 c = *cp++;
2582 a = *lp++;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002583
2584#ifndef PNG_SLOW_PAETH
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002585 p = b - c;
2586 pc = a - c;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002587#ifdef PNG_USE_ABS
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002588 pa = abs(p);
2589 pb = abs(pc);
2590 pc = abs(p + pc);
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002591#else
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002592 pa = p < 0 ? -p : p;
2593 pb = pc < 0 ? -pc : pc;
2594 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002595#endif
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002596 p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2597#else /* PNG_SLOW_PAETH */
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002598 p = a + b - c;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002599 pa = abs(p - a);
2600 pb = abs(p - b);
2601 pc = abs(p - c);
Guy Schalnate5a37791996-06-05 15:50:50 -05002602 if (pa <= pb && pa <= pc)
2603 p = a;
2604 else if (pb <= pc)
2605 p = b;
2606 else
2607 p = c;
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002608#endif /* PNG_SLOW_PAETH */
Guy Schalnate5a37791996-06-05 15:50:50 -05002609
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002610 v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
Guy Schalnate5a37791996-06-05 15:50:50 -05002611
2612 sum += (v < 128) ? v : 256 - v;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002613
2614 if (sum > lmins) /* We are already worse, don't continue. */
2615 break;
Guy Schalnate5a37791996-06-05 15:50:50 -05002616 }
Andreas Dilger47a0c421997-05-16 02:46:07 -05002617
2618#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2619 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2620 {
Glenn Randers-Pehrsond0dce401998-05-09 10:02:29 -05002621 int j;
Andreas Dilger47a0c421997-05-16 02:46:07 -05002622 png_uint_32 sumhi, sumlo;
2623 sumlo = sum & PNG_LOMASK;
2624 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2625
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002626 for (j = 0; j < num_p_filters; j++)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002627 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002628 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002629 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002630 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002631 PNG_WEIGHT_SHIFT;
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002632 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
Andreas Dilger47a0c421997-05-16 02:46:07 -05002633 PNG_WEIGHT_SHIFT;
2634 }
2635 }
2636
2637 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2638 PNG_COST_SHIFT;
2639 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2640 PNG_COST_SHIFT;
2641
2642 if (sumhi > PNG_HIMASK)
2643 sum = PNG_MAXSUM;
2644 else
2645 sum = (sumhi << PNG_HISHIFT) + sumlo;
2646 }
2647#endif
2648
Guy Schalnate5a37791996-06-05 15:50:50 -05002649 if (sum < mins)
2650 {
2651 best_row = png_ptr->paeth_row;
2652 }
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002653 }
2654
Andreas Dilger47a0c421997-05-16 02:46:07 -05002655 /* Do the actual writing of the filtered row data from the chosen filter. */
Glenn Randers-Pehrson896239b1998-04-21 15:03:57 -05002656
Guy Schalnate5a37791996-06-05 15:50:50 -05002657 png_write_filtered_row(png_ptr, best_row);
Andreas Dilger47a0c421997-05-16 02:46:07 -05002658
2659#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2660 /* Save the type of filter we picked this time for future calculations */
2661 if (png_ptr->num_prev_filters > 0)
2662 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002663 int j;
2664 for (j = 1; j < num_p_filters; j++)
Andreas Dilger47a0c421997-05-16 02:46:07 -05002665 {
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002666 png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
Andreas Dilger47a0c421997-05-16 02:46:07 -05002667 }
Glenn Randers-Pehrson1d963611998-05-02 12:52:25 -05002668 png_ptr->prev_filters[j] = best_row[0];
Andreas Dilger47a0c421997-05-16 02:46:07 -05002669 }
2670#endif
Guy Schalnate5a37791996-06-05 15:50:50 -05002671}
2672
2673
Andreas Dilger47a0c421997-05-16 02:46:07 -05002674/* Do the actual writing of a previously filtered row. */
Glenn Randers-Pehrson75294572000-05-06 14:09:57 -05002675void /* PRIVATE */
Guy Schalnate5a37791996-06-05 15:50:50 -05002676png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
2677{
Andreas Dilger47a0c421997-05-16 02:46:07 -05002678 png_debug(1, "in png_write_filtered_row\n");
2679 png_debug1(2, "filter = %d\n", filtered_row[0]);
Guy Schalnate5a37791996-06-05 15:50:50 -05002680 /* set up the zlib input buffer */
Glenn Randers-Pehrson5e5c1e12000-11-10 12:26:19 -06002681
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06002682 png_ptr->zstream.next_in = filtered_row;
2683 png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
Guy Schalnate5a37791996-06-05 15:50:50 -05002684 /* repeat until we have compressed all the data */
2685 do
Guy Schalnat51f0eb41995-09-26 05:22:39 -05002686 {
Guy Schalnate5a37791996-06-05 15:50:50 -05002687 int ret; /* return of zlib */
Guy Schalnat0d580581995-07-20 02:43:20 -05002688
Guy Schalnate5a37791996-06-05 15:50:50 -05002689 /* compress the data */
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06002690 ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
Guy Schalnate5a37791996-06-05 15:50:50 -05002691 /* check for compression errors */
2692 if (ret != Z_OK)
2693 {
Andreas Dilger47a0c421997-05-16 02:46:07 -05002694 if (png_ptr->zstream.msg != NULL)
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06002695 png_error(png_ptr, png_ptr->zstream.msg);
Guy Schalnate5a37791996-06-05 15:50:50 -05002696 else
2697 png_error(png_ptr, "zlib error");
2698 }
Guy Schalnat0d580581995-07-20 02:43:20 -05002699
Guy Schalnate5a37791996-06-05 15:50:50 -05002700 /* see if it is time to write another IDAT */
Andreas Dilger47a0c421997-05-16 02:46:07 -05002701 if (!(png_ptr->zstream.avail_out))
Guy Schalnate5a37791996-06-05 15:50:50 -05002702 {
2703 /* write the IDAT and reset the zlib output buffer */
2704 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06002705 png_ptr->zstream.next_out = png_ptr->zbuf;
2706 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
Guy Schalnate5a37791996-06-05 15:50:50 -05002707 }
2708 /* repeat until all data has been compressed */
Andreas Dilger02ad0ef1997-01-17 01:34:35 -06002709 } while (png_ptr->zstream.avail_in);
Guy Schalnate5a37791996-06-05 15:50:50 -05002710
Guy Schalnatc21f90c1996-06-17 16:24:45 -05002711 /* swap the current and previous rows */
Andreas Dilger47a0c421997-05-16 02:46:07 -05002712 if (png_ptr->prev_row != NULL)
Guy Schalnatc21f90c1996-06-17 16:24:45 -05002713 {
2714 png_bytep tptr;
2715
2716 tptr = png_ptr->prev_row;
2717 png_ptr->prev_row = png_ptr->row_buf;
2718 png_ptr->row_buf = tptr;
2719 }
2720
Guy Schalnate5a37791996-06-05 15:50:50 -05002721 /* finish row - updates counters and flushes zlib if last row */
2722 png_write_finish_row(png_ptr);
2723
2724#if defined(PNG_WRITE_FLUSH_SUPPORTED)
2725 png_ptr->flush_rows++;
2726
2727 if (png_ptr->flush_dist > 0 &&
2728 png_ptr->flush_rows >= png_ptr->flush_dist)
Guy Schalnat0d580581995-07-20 02:43:20 -05002729 {
Guy Schalnate5a37791996-06-05 15:50:50 -05002730 png_write_flush(png_ptr);
Guy Schalnat0d580581995-07-20 02:43:20 -05002731 }
Glenn Randers-Pehrson166c5a31999-12-10 09:43:02 -06002732#endif
Guy Schalnat0d580581995-07-20 02:43:20 -05002733}
Glenn Randers-Pehrson3097f612001-05-07 14:52:45 -05002734#endif /* PNG_WRITE_SUPPORTED */