2
/* pngwutil.c - utilities to write a PNG file
4
* libpng version 1.2.8 - December 3, 2004
5
* For conditions of distribution and use, see copyright notice in png.h
6
* Copyright (c) 1998-2004 Glenn Randers-Pehrson
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* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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#ifdef PNG_WRITE_SUPPORTED
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/* Place a 32-bit number into a buffer in PNG byte order. We work
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* with unsigned numbers for convenience, although one supported
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* ancillary chunk uses signed (two's complement) numbers.
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png_save_uint_32(png_bytep buf, png_uint_32 i)
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buf[0] = (png_byte)((i >> 24) & 0xff);
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buf[1] = (png_byte)((i >> 16) & 0xff);
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buf[2] = (png_byte)((i >> 8) & 0xff);
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buf[3] = (png_byte)(i & 0xff);
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#if defined(PNG_WRITE_pCAL_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
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/* The png_save_int_32 function assumes integers are stored in two's
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* complement format. If this isn't the case, then this routine needs to
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* be modified to write data in two's complement format.
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png_save_int_32(png_bytep buf, png_int_32 i)
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buf[0] = (png_byte)((i >> 24) & 0xff);
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buf[1] = (png_byte)((i >> 16) & 0xff);
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buf[2] = (png_byte)((i >> 8) & 0xff);
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buf[3] = (png_byte)(i & 0xff);
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/* Place a 16-bit number into a buffer in PNG byte order.
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* The parameter is declared unsigned int, not png_uint_16,
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* just to avoid potential problems on pre-ANSI C compilers.
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png_save_uint_16(png_bytep buf, unsigned int i)
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buf[0] = (png_byte)((i >> 8) & 0xff);
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buf[1] = (png_byte)(i & 0xff);
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/* Write a PNG chunk all at once. The type is an array of ASCII characters
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* representing the chunk name. The array must be at least 4 bytes in
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* length, and does not need to be null terminated. To be safe, pass the
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* pre-defined chunk names here, and if you need a new one, define it
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* where the others are defined. The length is the length of the data.
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* All the data must be present. If that is not possible, use the
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* png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
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png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
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png_bytep data, png_size_t length)
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png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
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png_write_chunk_data(png_ptr, data, length);
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png_write_chunk_end(png_ptr);
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/* Write the start of a PNG chunk. The type is the chunk type.
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* The total_length is the sum of the lengths of all the data you will be
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* passing in png_write_chunk_data().
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png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
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png_debug2(0, "Writing %s chunk (%lu bytes)\n", chunk_name, length);
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/* write the length */
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png_save_uint_32(buf, length);
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png_write_data(png_ptr, buf, (png_size_t)4);
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/* write the chunk name */
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png_write_data(png_ptr, chunk_name, (png_size_t)4);
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/* reset the crc and run it over the chunk name */
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png_reset_crc(png_ptr);
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png_calculate_crc(png_ptr, chunk_name, (png_size_t)4);
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/* Write the data of a PNG chunk started with png_write_chunk_start().
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* Note that multiple calls to this function are allowed, and that the
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* sum of the lengths from these calls *must* add up to the total_length
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* given to png_write_chunk_start().
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png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
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/* write the data, and run the CRC over it */
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if (data != NULL && length > 0)
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png_calculate_crc(png_ptr, data, length);
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png_write_data(png_ptr, data, length);
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/* Finish a chunk started with png_write_chunk_start(). */
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png_write_chunk_end(png_structp png_ptr)
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png_save_uint_32(buf, png_ptr->crc);
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png_write_data(png_ptr, buf, (png_size_t)4);
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/* Simple function to write the signature. If we have already written
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* the magic bytes of the signature, or more likely, the PNG stream is
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* being embedded into another stream and doesn't need its own signature,
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* we should call png_set_sig_bytes() to tell libpng how many of the
126
* bytes have already been written.
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png_write_sig(png_structp png_ptr)
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png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
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/* write the rest of the 8 byte signature */
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png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
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(png_size_t)8 - png_ptr->sig_bytes);
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if(png_ptr->sig_bytes < 3)
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png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
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#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
141
* This pair of functions encapsulates the operation of (a) compressing a
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* text string, and (b) issuing it later as a series of chunk data writes.
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* The compression_state structure is shared context for these functions
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* set up by the caller in order to make the whole mess thread-safe.
149
char *input; /* the uncompressed input data */
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int input_len; /* its length */
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int num_output_ptr; /* number of output pointers used */
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int max_output_ptr; /* size of output_ptr */
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png_charpp output_ptr; /* array of pointers to output */
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/* compress given text into storage in the png_ptr structure */
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static int /* PRIVATE */
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png_text_compress(png_structp png_ptr,
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png_charp text, png_size_t text_len, int compression,
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compression_state *comp)
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comp->num_output_ptr = comp->max_output_ptr = 0;
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comp->output_ptr = NULL;
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/* we may just want to pass the text right through */
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if (compression == PNG_TEXT_COMPRESSION_NONE)
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comp->input_len = text_len;
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return((int)text_len);
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if (compression >= PNG_TEXT_COMPRESSION_LAST)
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#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
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sprintf(msg, "Unknown compression type %d", compression);
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png_warning(png_ptr, msg);
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png_warning(png_ptr, "Unknown compression type");
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/* We can't write the chunk until we find out how much data we have,
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* which means we need to run the compressor first and save the
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* output. This shouldn't be a problem, as the vast majority of
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* comments should be reasonable, but we will set up an array of
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* malloc'd pointers to be sure.
193
* If we knew the application was well behaved, we could simplify this
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* greatly by assuming we can always malloc an output buffer large
195
* enough to hold the compressed text ((1001 * text_len / 1000) + 12)
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* 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
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* wouldn't cause a failure, just a slowdown due to swapping).
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/* set up the compression buffers */
203
png_ptr->zstream.avail_in = (uInt)text_len;
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png_ptr->zstream.next_in = (Bytef *)text;
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png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
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png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;
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/* this is the same compression loop as in png_write_row() */
211
/* compress the data */
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ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
216
if (png_ptr->zstream.msg != NULL)
217
png_error(png_ptr, png_ptr->zstream.msg);
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png_error(png_ptr, "zlib error");
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/* check to see if we need more room */
222
if (!(png_ptr->zstream.avail_out))
224
/* make sure the output array has room */
225
if (comp->num_output_ptr >= comp->max_output_ptr)
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old_max = comp->max_output_ptr;
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comp->max_output_ptr = comp->num_output_ptr + 4;
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if (comp->output_ptr != NULL)
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old_ptr = comp->output_ptr;
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comp->output_ptr = (png_charpp)png_malloc(png_ptr,
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(png_uint_32)(comp->max_output_ptr *
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png_sizeof (png_charpp)));
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png_memcpy(comp->output_ptr, old_ptr, old_max
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* png_sizeof (png_charp));
241
png_free(png_ptr, old_ptr);
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comp->output_ptr = (png_charpp)png_malloc(png_ptr,
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(png_uint_32)(comp->max_output_ptr *
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png_sizeof (png_charp)));
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comp->output_ptr[comp->num_output_ptr] = (png_charp)png_malloc(png_ptr,
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(png_uint_32)png_ptr->zbuf_size);
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png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
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comp->num_output_ptr++;
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/* and reset the buffer */
257
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
258
png_ptr->zstream.next_out = png_ptr->zbuf;
260
/* continue until we don't have any more to compress */
261
} while (png_ptr->zstream.avail_in);
263
/* finish the compression */
266
/* tell zlib we are finished */
267
ret = deflate(&png_ptr->zstream, Z_FINISH);
271
/* check to see if we need more room */
272
if (!(png_ptr->zstream.avail_out))
274
/* check to make sure our output array has room */
275
if (comp->num_output_ptr >= comp->max_output_ptr)
279
old_max = comp->max_output_ptr;
280
comp->max_output_ptr = comp->num_output_ptr + 4;
281
if (comp->output_ptr != NULL)
285
old_ptr = comp->output_ptr;
286
/* This could be optimized to realloc() */
287
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
288
(png_uint_32)(comp->max_output_ptr *
289
png_sizeof (png_charpp)));
290
png_memcpy(comp->output_ptr, old_ptr,
291
old_max * png_sizeof (png_charp));
292
png_free(png_ptr, old_ptr);
295
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
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(png_uint_32)(comp->max_output_ptr *
297
png_sizeof (png_charp)));
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);
303
png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
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comp->num_output_ptr++;
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;
312
else if (ret != Z_STREAM_END)
314
/* we got an error */
315
if (png_ptr->zstream.msg != NULL)
316
png_error(png_ptr, png_ptr->zstream.msg);
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png_error(png_ptr, "zlib error");
320
} while (ret != Z_STREAM_END);
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)
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text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
327
return((int)text_len);
330
/* ship the compressed text out via chunk writes */
331
static void /* PRIVATE */
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png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
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/* handle the no-compression case */
339
png_write_chunk_data(png_ptr, (png_bytep)comp->input,
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(png_size_t)comp->input_len);
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/* write saved output buffers, if any */
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for (i = 0; i < comp->num_output_ptr; i++)
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png_write_chunk_data(png_ptr,(png_bytep)comp->output_ptr[i],
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png_free(png_ptr, comp->output_ptr[i]);
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comp->output_ptr[i]=NULL;
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if (comp->max_output_ptr != 0)
353
png_free(png_ptr, comp->output_ptr);
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comp->output_ptr=NULL;
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/* write anything left in zbuf */
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if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
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png_write_chunk_data(png_ptr, png_ptr->zbuf,
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png_ptr->zbuf_size - png_ptr->zstream.avail_out);
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/* reset zlib for another zTXt/iTXt or image data */
361
deflateReset(&png_ptr->zstream);
362
png_ptr->zstream.data_type = Z_BINARY;
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/* Write the IHDR chunk, and update the png_struct with the necessary
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* information. Note that the rest of this code depends upon this
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* information being correct.
371
png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
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int bit_depth, int color_type, int compression_type, int filter_type,
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#ifdef PNG_USE_LOCAL_ARRAYS
378
png_byte buf[13]; /* buffer to store the IHDR info */
380
png_debug(1, "in png_write_IHDR\n");
381
/* Check that we have valid input data from the application info */
384
case PNG_COLOR_TYPE_GRAY:
391
case 16: png_ptr->channels = 1; break;
392
default: png_error(png_ptr,"Invalid bit depth for grayscale image");
395
case PNG_COLOR_TYPE_RGB:
396
if (bit_depth != 8 && bit_depth != 16)
397
png_error(png_ptr, "Invalid bit depth for RGB image");
398
png_ptr->channels = 3;
400
case PNG_COLOR_TYPE_PALETTE:
406
case 8: png_ptr->channels = 1; break;
407
default: png_error(png_ptr, "Invalid bit depth for paletted image");
410
case PNG_COLOR_TYPE_GRAY_ALPHA:
411
if (bit_depth != 8 && bit_depth != 16)
412
png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
413
png_ptr->channels = 2;
415
case PNG_COLOR_TYPE_RGB_ALPHA:
416
if (bit_depth != 8 && bit_depth != 16)
417
png_error(png_ptr, "Invalid bit depth for RGBA image");
418
png_ptr->channels = 4;
421
png_error(png_ptr, "Invalid image color type specified");
424
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
426
png_warning(png_ptr, "Invalid compression type specified");
427
compression_type = PNG_COMPRESSION_TYPE_BASE;
430
/* 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
440
#if defined(PNG_MNG_FEATURES_SUPPORTED)
441
!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
442
((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
443
(color_type == PNG_COLOR_TYPE_RGB ||
444
color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
445
(filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
447
filter_type != PNG_FILTER_TYPE_BASE)
449
png_warning(png_ptr, "Invalid filter type specified");
450
filter_type = PNG_FILTER_TYPE_BASE;
453
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
454
if (interlace_type != PNG_INTERLACE_NONE &&
455
interlace_type != PNG_INTERLACE_ADAM7)
457
png_warning(png_ptr, "Invalid interlace type specified");
458
interlace_type = PNG_INTERLACE_ADAM7;
461
interlace_type=PNG_INTERLACE_NONE;
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;
468
#if defined(PNG_MNG_FEATURES_SUPPORTED)
469
png_ptr->filter_type = (png_byte)filter_type;
471
png_ptr->compression_type = (png_byte)compression_type;
472
png_ptr->width = width;
473
png_ptr->height = height;
475
png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
476
png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
477
/* 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;
482
/* pack the header information into the buffer */
483
png_save_uint_32(buf, width);
484
png_save_uint_32(buf + 4, height);
485
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;
491
/* write the chunk */
492
png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
494
/* initialize zlib with PNG info */
495
png_ptr->zstream.zalloc = png_zalloc;
496
png_ptr->zstream.zfree = png_zfree;
497
png_ptr->zstream.opaque = (voidpf)png_ptr;
498
if (!(png_ptr->do_filter))
500
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
501
png_ptr->bit_depth < 8)
502
png_ptr->do_filter = PNG_FILTER_NONE;
504
png_ptr->do_filter = PNG_ALL_FILTERS;
506
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
508
if (png_ptr->do_filter != PNG_FILTER_NONE)
509
png_ptr->zlib_strategy = Z_FILTERED;
511
png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
513
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
514
png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
515
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
516
png_ptr->zlib_mem_level = 8;
517
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
518
png_ptr->zlib_window_bits = 15;
519
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
520
png_ptr->zlib_method = 8;
521
deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
522
png_ptr->zlib_method, png_ptr->zlib_window_bits,
523
png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
524
png_ptr->zstream.next_out = png_ptr->zbuf;
525
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
526
/* 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;
530
png_ptr->mode = PNG_HAVE_IHDR;
533
/* write the palette. We are careful not to trust png_color to be in the
534
* correct order for PNG, so people can redefine it to any convenient
538
png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
540
#ifdef PNG_USE_LOCAL_ARRAYS
547
png_debug(1, "in png_write_PLTE\n");
549
#if defined(PNG_MNG_FEATURES_SUPPORTED)
550
!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
552
num_pal == 0) || num_pal > 256)
554
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
556
png_error(png_ptr, "Invalid number of colors in palette");
560
png_warning(png_ptr, "Invalid number of colors in palette");
565
if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
568
"Ignoring request to write a PLTE chunk in grayscale PNG");
572
png_ptr->num_palette = (png_uint_16)num_pal;
573
png_debug1(3, "num_palette = %d\n", png_ptr->num_palette);
575
png_write_chunk_start(png_ptr, (png_bytep)png_PLTE, num_pal * 3);
576
#ifndef PNG_NO_POINTER_INDEXING
577
for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
579
buf[0] = pal_ptr->red;
580
buf[1] = pal_ptr->green;
581
buf[2] = pal_ptr->blue;
582
png_write_chunk_data(png_ptr, buf, (png_size_t)3);
585
/* This is a little slower but some buggy compilers need to do this instead */
587
for (i = 0; i < num_pal; i++)
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);
595
png_write_chunk_end(png_ptr);
596
png_ptr->mode |= PNG_HAVE_PLTE;
599
/* write an IDAT chunk */
601
png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
603
#ifdef PNG_USE_LOCAL_ARRAYS
606
png_debug(1, "in png_write_IDAT\n");
608
/* 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)
613
unsigned int z_cmf = data[0]; /* zlib compression method and flags */
614
if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
616
/* Avoid memory underflows and multiplication overflows. */
617
/* The conditions below are practically always satisfied;
618
however, they still must be checked. */
620
png_ptr->height < 16384 && png_ptr->width < 16384)
622
png_uint_32 uncompressed_idat_size = png_ptr->height *
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)
631
half_z_window_size >>= 1;
633
z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
634
if (data[0] != (png_byte)z_cmf)
636
data[0] = (png_byte)z_cmf;
638
data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f);
644
"Invalid zlib compression method or flags in IDAT");
647
png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
648
png_ptr->mode |= PNG_HAVE_IDAT;
651
/* write an IEND chunk */
653
png_write_IEND(png_structp png_ptr)
655
#ifdef PNG_USE_LOCAL_ARRAYS
658
png_debug(1, "in png_write_IEND\n");
659
png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,
661
png_ptr->mode |= PNG_HAVE_IEND;
664
#if defined(PNG_WRITE_gAMA_SUPPORTED)
665
/* write a gAMA chunk */
666
#ifdef PNG_FLOATING_POINT_SUPPORTED
668
png_write_gAMA(png_structp png_ptr, double file_gamma)
670
#ifdef PNG_USE_LOCAL_ARRAYS
676
png_debug(1, "in png_write_gAMA\n");
677
/* file_gamma is saved in 1/100,000ths */
678
igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
679
png_save_uint_32(buf, igamma);
680
png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
683
#ifdef PNG_FIXED_POINT_SUPPORTED
685
png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
687
#ifdef PNG_USE_LOCAL_ARRAYS
692
png_debug(1, "in png_write_gAMA\n");
693
/* file_gamma is saved in 1/100,000ths */
694
png_save_uint_32(buf, (png_uint_32)file_gamma);
695
png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
700
#if defined(PNG_WRITE_sRGB_SUPPORTED)
701
/* write a sRGB chunk */
703
png_write_sRGB(png_structp png_ptr, int srgb_intent)
705
#ifdef PNG_USE_LOCAL_ARRAYS
710
png_debug(1, "in png_write_sRGB\n");
711
if(srgb_intent >= PNG_sRGB_INTENT_LAST)
713
"Invalid sRGB rendering intent specified");
714
buf[0]=(png_byte)srgb_intent;
715
png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
719
#if defined(PNG_WRITE_iCCP_SUPPORTED)
720
/* write an iCCP chunk */
722
png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
723
png_charp profile, int profile_len)
725
#ifdef PNG_USE_LOCAL_ARRAYS
730
compression_state comp;
732
png_debug(1, "in png_write_iCCP\n");
733
if (name == NULL || (name_len = png_check_keyword(png_ptr, name,
736
png_warning(png_ptr, "Empty keyword in iCCP chunk");
740
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
741
png_warning(png_ptr, "Unknown compression type in iCCP chunk");
747
profile_len = png_text_compress(png_ptr, profile, (png_size_t)profile_len,
748
PNG_COMPRESSION_TYPE_BASE, &comp);
750
/* make sure we include the NULL after the name and the compression type */
751
png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
752
(png_uint_32)name_len+profile_len+2);
753
new_name[name_len+1]=0x00;
754
png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 2);
757
png_write_compressed_data_out(png_ptr, &comp);
759
png_write_chunk_end(png_ptr);
760
png_free(png_ptr, new_name);
764
#if defined(PNG_WRITE_sPLT_SUPPORTED)
765
/* write a sPLT chunk */
767
png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
769
#ifdef PNG_USE_LOCAL_ARRAYS
774
png_byte entrybuf[10];
775
int entry_size = (spalette->depth == 8 ? 6 : 10);
776
int palette_size = entry_size * spalette->nentries;
778
#ifdef PNG_NO_POINTER_INDEXING
782
png_debug(1, "in png_write_sPLT\n");
783
if (spalette->name == NULL || (name_len = png_check_keyword(png_ptr,
784
spalette->name, &new_name))==0)
786
png_warning(png_ptr, "Empty keyword in sPLT chunk");
790
/* make sure we include the NULL after the name */
791
png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
792
(png_uint_32)(name_len + 2 + palette_size));
793
png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 1);
794
png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, 1);
796
/* loop through each palette entry, writing appropriately */
797
#ifndef PNG_NO_POINTER_INDEXING
798
for (ep = spalette->entries; ep<spalette->entries+spalette->nentries; ep++)
800
if (spalette->depth == 8)
802
entrybuf[0] = (png_byte)ep->red;
803
entrybuf[1] = (png_byte)ep->green;
804
entrybuf[2] = (png_byte)ep->blue;
805
entrybuf[3] = (png_byte)ep->alpha;
806
png_save_uint_16(entrybuf + 4, ep->frequency);
810
png_save_uint_16(entrybuf + 0, ep->red);
811
png_save_uint_16(entrybuf + 2, ep->green);
812
png_save_uint_16(entrybuf + 4, ep->blue);
813
png_save_uint_16(entrybuf + 6, ep->alpha);
814
png_save_uint_16(entrybuf + 8, ep->frequency);
816
png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
819
ep=spalette->entries;
820
for (i=0; i>spalette->nentries; i++)
822
if (spalette->depth == 8)
824
entrybuf[0] = (png_byte)ep[i].red;
825
entrybuf[1] = (png_byte)ep[i].green;
826
entrybuf[2] = (png_byte)ep[i].blue;
827
entrybuf[3] = (png_byte)ep[i].alpha;
828
png_save_uint_16(entrybuf + 4, ep[i].frequency);
832
png_save_uint_16(entrybuf + 0, ep[i].red);
833
png_save_uint_16(entrybuf + 2, ep[i].green);
834
png_save_uint_16(entrybuf + 4, ep[i].blue);
835
png_save_uint_16(entrybuf + 6, ep[i].alpha);
836
png_save_uint_16(entrybuf + 8, ep[i].frequency);
838
png_write_chunk_data(png_ptr, entrybuf, entry_size);
842
png_write_chunk_end(png_ptr);
843
png_free(png_ptr, new_name);
847
#if defined(PNG_WRITE_sBIT_SUPPORTED)
848
/* write the sBIT chunk */
850
png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
852
#ifdef PNG_USE_LOCAL_ARRAYS
858
png_debug(1, "in png_write_sBIT\n");
859
/* make sure we don't depend upon the order of PNG_COLOR_8 */
860
if (color_type & PNG_COLOR_MASK_COLOR)
864
maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
865
png_ptr->usr_bit_depth);
866
if (sbit->red == 0 || sbit->red > maxbits ||
867
sbit->green == 0 || sbit->green > maxbits ||
868
sbit->blue == 0 || sbit->blue > maxbits)
870
png_warning(png_ptr, "Invalid sBIT depth specified");
874
buf[1] = sbit->green;
880
if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
882
png_warning(png_ptr, "Invalid sBIT depth specified");
889
if (color_type & PNG_COLOR_MASK_ALPHA)
891
if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
893
png_warning(png_ptr, "Invalid sBIT depth specified");
896
buf[size++] = sbit->alpha;
899
png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
903
#if defined(PNG_WRITE_cHRM_SUPPORTED)
904
/* write the cHRM chunk */
905
#ifdef PNG_FLOATING_POINT_SUPPORTED
907
png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
908
double red_x, double red_y, double green_x, double green_y,
909
double blue_x, double blue_y)
911
#ifdef PNG_USE_LOCAL_ARRAYS
917
png_debug(1, "in png_write_cHRM\n");
918
/* each value is saved in 1/100,000ths */
919
if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 ||
920
white_x + white_y > 1.0)
922
png_warning(png_ptr, "Invalid cHRM white point specified");
923
#if !defined(PNG_NO_CONSOLE_IO)
924
fprintf(stderr,"white_x=%f, white_y=%f\n",white_x, white_y);
928
itemp = (png_uint_32)(white_x * 100000.0 + 0.5);
929
png_save_uint_32(buf, itemp);
930
itemp = (png_uint_32)(white_y * 100000.0 + 0.5);
931
png_save_uint_32(buf + 4, itemp);
933
if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 ||
936
png_warning(png_ptr, "Invalid cHRM red point specified");
939
itemp = (png_uint_32)(red_x * 100000.0 + 0.5);
940
png_save_uint_32(buf + 8, itemp);
941
itemp = (png_uint_32)(red_y * 100000.0 + 0.5);
942
png_save_uint_32(buf + 12, itemp);
944
if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 ||
945
green_x + green_y > 1.0)
947
png_warning(png_ptr, "Invalid cHRM green point specified");
950
itemp = (png_uint_32)(green_x * 100000.0 + 0.5);
951
png_save_uint_32(buf + 16, itemp);
952
itemp = (png_uint_32)(green_y * 100000.0 + 0.5);
953
png_save_uint_32(buf + 20, itemp);
955
if (blue_x < 0 || blue_x > 0.8 || blue_y < 0 || blue_y > 0.8 ||
956
blue_x + blue_y > 1.0)
958
png_warning(png_ptr, "Invalid cHRM blue point specified");
961
itemp = (png_uint_32)(blue_x * 100000.0 + 0.5);
962
png_save_uint_32(buf + 24, itemp);
963
itemp = (png_uint_32)(blue_y * 100000.0 + 0.5);
964
png_save_uint_32(buf + 28, itemp);
966
png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
969
#ifdef PNG_FIXED_POINT_SUPPORTED
971
png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
972
png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
973
png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
974
png_fixed_point blue_y)
976
#ifdef PNG_USE_LOCAL_ARRAYS
981
png_debug(1, "in png_write_cHRM\n");
982
/* each value is saved in 1/100,000ths */
983
if (white_x > 80000L || white_y > 80000L || white_x + white_y > 100000L)
985
png_warning(png_ptr, "Invalid fixed cHRM white point specified");
986
#if !defined(PNG_NO_CONSOLE_IO)
987
fprintf(stderr,"white_x=%ld, white_y=%ld\n",white_x, white_y);
991
png_save_uint_32(buf, (png_uint_32)white_x);
992
png_save_uint_32(buf + 4, (png_uint_32)white_y);
994
if (red_x > 80000L || red_y > 80000L || red_x + red_y > 100000L)
996
png_warning(png_ptr, "Invalid cHRM fixed red point specified");
999
png_save_uint_32(buf + 8, (png_uint_32)red_x);
1000
png_save_uint_32(buf + 12, (png_uint_32)red_y);
1002
if (green_x > 80000L || green_y > 80000L || green_x + green_y > 100000L)
1004
png_warning(png_ptr, "Invalid fixed cHRM green point specified");
1007
png_save_uint_32(buf + 16, (png_uint_32)green_x);
1008
png_save_uint_32(buf + 20, (png_uint_32)green_y);
1010
if (blue_x > 80000L || blue_y > 80000L || blue_x + blue_y > 100000L)
1012
png_warning(png_ptr, "Invalid fixed cHRM blue point specified");
1015
png_save_uint_32(buf + 24, (png_uint_32)blue_x);
1016
png_save_uint_32(buf + 28, (png_uint_32)blue_y);
1018
png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
1023
#if defined(PNG_WRITE_tRNS_SUPPORTED)
1024
/* write the tRNS chunk */
1026
png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
1027
int num_trans, int color_type)
1029
#ifdef PNG_USE_LOCAL_ARRAYS
1034
png_debug(1, "in png_write_tRNS\n");
1035
if (color_type == PNG_COLOR_TYPE_PALETTE)
1037
if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
1039
png_warning(png_ptr,"Invalid number of transparent colors specified");
1042
/* write the chunk out as it is */
1043
png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans, (png_size_t)num_trans);
1045
else if (color_type == PNG_COLOR_TYPE_GRAY)
1047
/* one 16 bit value */
1048
if(tran->gray >= (1 << png_ptr->bit_depth))
1050
png_warning(png_ptr,
1051
"Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
1054
png_save_uint_16(buf, tran->gray);
1055
png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
1057
else if (color_type == PNG_COLOR_TYPE_RGB)
1059
/* three 16 bit values */
1060
png_save_uint_16(buf, tran->red);
1061
png_save_uint_16(buf + 2, tran->green);
1062
png_save_uint_16(buf + 4, tran->blue);
1063
if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1065
png_warning(png_ptr,
1066
"Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
1069
png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
1073
png_warning(png_ptr, "Can't write tRNS with an alpha channel");
1078
#if defined(PNG_WRITE_bKGD_SUPPORTED)
1079
/* write the background chunk */
1081
png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
1083
#ifdef PNG_USE_LOCAL_ARRAYS
1088
png_debug(1, "in png_write_bKGD\n");
1089
if (color_type == PNG_COLOR_TYPE_PALETTE)
1092
#if defined(PNG_MNG_FEATURES_SUPPORTED)
1093
(png_ptr->num_palette ||
1094
(!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
1096
back->index > png_ptr->num_palette)
1098
png_warning(png_ptr, "Invalid background palette index");
1101
buf[0] = back->index;
1102
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
1104
else if (color_type & PNG_COLOR_MASK_COLOR)
1106
png_save_uint_16(buf, back->red);
1107
png_save_uint_16(buf + 2, back->green);
1108
png_save_uint_16(buf + 4, back->blue);
1109
if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1111
png_warning(png_ptr,
1112
"Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
1115
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
1119
if(back->gray >= (1 << png_ptr->bit_depth))
1121
png_warning(png_ptr,
1122
"Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
1125
png_save_uint_16(buf, back->gray);
1126
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
1131
#if defined(PNG_WRITE_hIST_SUPPORTED)
1132
/* write the histogram */
1134
png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
1136
#ifdef PNG_USE_LOCAL_ARRAYS
1142
png_debug(1, "in png_write_hIST\n");
1143
if (num_hist > (int)png_ptr->num_palette)
1145
png_debug2(3, "num_hist = %d, num_palette = %d\n", num_hist,
1146
png_ptr->num_palette);
1147
png_warning(png_ptr, "Invalid number of histogram entries specified");
1151
png_write_chunk_start(png_ptr, (png_bytep)png_hIST, (png_uint_32)(num_hist * 2));
1152
for (i = 0; i < num_hist; i++)
1154
png_save_uint_16(buf, hist[i]);
1155
png_write_chunk_data(png_ptr, buf, (png_size_t)2);
1157
png_write_chunk_end(png_ptr);
1161
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
1162
defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
1163
/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
1164
* and if invalid, correct the keyword rather than discarding the entire
1165
* chunk. The PNG 1.0 specification requires keywords 1-79 characters in
1166
* length, forbids leading or trailing whitespace, multiple internal spaces,
1167
* and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
1169
* The new_key is allocated to hold the corrected keyword and must be freed
1170
* by the calling routine. This avoids problems with trying to write to
1171
* static keywords without having to have duplicate copies of the strings.
1173
png_size_t /* PRIVATE */
1174
png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
1181
png_debug(1, "in png_check_keyword\n");
1184
if (key == NULL || (key_len = png_strlen(key)) == 0)
1186
png_warning(png_ptr, "zero length keyword");
1187
return ((png_size_t)0);
1190
png_debug1(2, "Keyword to be checked is '%s'\n", key);
1192
*new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
1193
if (*new_key == NULL)
1195
png_warning(png_ptr, "Out of memory while procesing keyword");
1196
return ((png_size_t)0);
1199
/* Replace non-printing characters with a blank and print a warning */
1200
for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
1202
if (*kp < 0x20 || (*kp > 0x7E && (png_byte)*kp < 0xA1))
1204
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
1207
sprintf(msg, "invalid keyword character 0x%02X", *kp);
1208
png_warning(png_ptr, msg);
1210
png_warning(png_ptr, "invalid character in keyword");
1221
/* Remove any trailing white space. */
1222
kp = *new_key + key_len - 1;
1225
png_warning(png_ptr, "trailing spaces removed from keyword");
1234
/* Remove any leading white space. */
1238
png_warning(png_ptr, "leading spaces removed from keyword");
1247
png_debug1(2, "Checking for multiple internal spaces in '%s'\n", kp);
1249
/* Remove multiple internal spaces. */
1250
for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
1252
if (*kp == ' ' && kflag == 0)
1257
else if (*kp == ' ')
1270
png_warning(png_ptr, "extra interior spaces removed from keyword");
1274
png_free(png_ptr, *new_key);
1276
png_warning(png_ptr, "Zero length keyword");
1281
png_warning(png_ptr, "keyword length must be 1 - 79 characters");
1290
#if defined(PNG_WRITE_tEXt_SUPPORTED)
1291
/* write a tEXt chunk */
1293
png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
1294
png_size_t text_len)
1296
#ifdef PNG_USE_LOCAL_ARRAYS
1302
png_debug(1, "in png_write_tEXt\n");
1303
if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1305
png_warning(png_ptr, "Empty keyword in tEXt chunk");
1309
if (text == NULL || *text == '\0')
1312
text_len = png_strlen(text);
1314
/* make sure we include the 0 after the key */
1315
png_write_chunk_start(png_ptr, (png_bytep)png_tEXt, (png_uint_32)key_len+text_len+1);
1317
* We leave it to the application to meet PNG-1.0 requirements on the
1318
* contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1319
* any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1320
* The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1322
png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
1324
png_write_chunk_data(png_ptr, (png_bytep)text, text_len);
1326
png_write_chunk_end(png_ptr);
1327
png_free(png_ptr, new_key);
1331
#if defined(PNG_WRITE_zTXt_SUPPORTED)
1332
/* write a compressed text chunk */
1334
png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
1335
png_size_t text_len, int compression)
1337
#ifdef PNG_USE_LOCAL_ARRAYS
1343
compression_state comp;
1345
png_debug(1, "in png_write_zTXt\n");
1347
if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1349
png_warning(png_ptr, "Empty keyword in zTXt chunk");
1353
if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
1355
png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
1356
png_free(png_ptr, new_key);
1360
text_len = png_strlen(text);
1362
png_free(png_ptr, new_key);
1364
/* compute the compressed data; do it now for the length */
1365
text_len = png_text_compress(png_ptr, text, text_len, compression,
1368
/* write start of chunk */
1369
png_write_chunk_start(png_ptr, (png_bytep)png_zTXt, (png_uint_32)
1370
(key_len+text_len+2));
1372
png_write_chunk_data(png_ptr, (png_bytep)key, key_len + 1);
1373
buf[0] = (png_byte)compression;
1374
/* write compression */
1375
png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);
1376
/* write the compressed data */
1377
png_write_compressed_data_out(png_ptr, &comp);
1379
/* close the chunk */
1380
png_write_chunk_end(png_ptr);
1384
#if defined(PNG_WRITE_iTXt_SUPPORTED)
1385
/* write an iTXt chunk */
1387
png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
1388
png_charp lang, png_charp lang_key, png_charp text)
1390
#ifdef PNG_USE_LOCAL_ARRAYS
1393
png_size_t lang_len, key_len, lang_key_len, text_len;
1394
png_charp new_lang, new_key;
1396
compression_state comp;
1398
png_debug(1, "in png_write_iTXt\n");
1400
if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1402
png_warning(png_ptr, "Empty keyword in iTXt chunk");
1405
if (lang == NULL || (lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
1407
png_warning(png_ptr, "Empty language field in iTXt chunk");
1412
if (lang_key == NULL)
1415
lang_key_len = png_strlen(lang_key);
1420
text_len = png_strlen(text);
1422
/* compute the compressed data; do it now for the length */
1423
text_len = png_text_compress(png_ptr, text, text_len, compression-2,
1427
/* make sure we include the compression flag, the compression byte,
1428
* and the NULs after the key, lang, and lang_key parts */
1430
png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
1432
5 /* comp byte, comp flag, terminators for key, lang and lang_key */
1439
* We leave it to the application to meet PNG-1.0 requirements on the
1440
* contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1441
* any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1442
* The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1444
png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
1446
/* set the compression flag */
1447
if (compression == PNG_ITXT_COMPRESSION_NONE || \
1448
compression == PNG_TEXT_COMPRESSION_NONE)
1450
else /* compression == PNG_ITXT_COMPRESSION_zTXt */
1452
/* set the compression method */
1454
png_write_chunk_data(png_ptr, cbuf, 2);
1457
png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf), lang_len + 1);
1458
png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf), lang_key_len + 1);
1459
png_write_compressed_data_out(png_ptr, &comp);
1461
png_write_chunk_end(png_ptr);
1462
png_free(png_ptr, new_key);
1464
png_free(png_ptr, new_lang);
1468
#if defined(PNG_WRITE_oFFs_SUPPORTED)
1469
/* write the oFFs chunk */
1471
png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
1474
#ifdef PNG_USE_LOCAL_ARRAYS
1479
png_debug(1, "in png_write_oFFs\n");
1480
if (unit_type >= PNG_OFFSET_LAST)
1481
png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
1483
png_save_int_32(buf, x_offset);
1484
png_save_int_32(buf + 4, y_offset);
1485
buf[8] = (png_byte)unit_type;
1487
png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
1491
#if defined(PNG_WRITE_pCAL_SUPPORTED)
1492
/* write the pCAL chunk (described in the PNG extensions document) */
1494
png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
1495
png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
1497
#ifdef PNG_USE_LOCAL_ARRAYS
1500
png_size_t purpose_len, units_len, total_len;
1501
png_uint_32p params_len;
1503
png_charp new_purpose;
1506
png_debug1(1, "in png_write_pCAL (%d parameters)\n", nparams);
1507
if (type >= PNG_EQUATION_LAST)
1508
png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
1510
purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
1511
png_debug1(3, "pCAL purpose length = %d\n", (int)purpose_len);
1512
units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
1513
png_debug1(3, "pCAL units length = %d\n", (int)units_len);
1514
total_len = purpose_len + units_len + 10;
1516
params_len = (png_uint_32p)png_malloc(png_ptr, (png_uint_32)(nparams
1517
*png_sizeof(png_uint_32)));
1519
/* Find the length of each parameter, making sure we don't count the
1520
null terminator for the last parameter. */
1521
for (i = 0; i < nparams; i++)
1523
params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
1524
png_debug2(3, "pCAL parameter %d length = %lu\n", i, params_len[i]);
1525
total_len += (png_size_t)params_len[i];
1528
png_debug1(3, "pCAL total length = %d\n", (int)total_len);
1529
png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
1530
png_write_chunk_data(png_ptr, (png_bytep)new_purpose, purpose_len);
1531
png_save_int_32(buf, X0);
1532
png_save_int_32(buf + 4, X1);
1533
buf[8] = (png_byte)type;
1534
buf[9] = (png_byte)nparams;
1535
png_write_chunk_data(png_ptr, buf, (png_size_t)10);
1536
png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);
1538
png_free(png_ptr, new_purpose);
1540
for (i = 0; i < nparams; i++)
1542
png_write_chunk_data(png_ptr, (png_bytep)params[i],
1543
(png_size_t)params_len[i]);
1546
png_free(png_ptr, params_len);
1547
png_write_chunk_end(png_ptr);
1551
#if defined(PNG_WRITE_sCAL_SUPPORTED)
1552
/* write the sCAL chunk */
1553
#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
1555
png_write_sCAL(png_structp png_ptr, int unit, double width,double height)
1557
#ifdef PNG_USE_LOCAL_ARRAYS
1560
png_size_t total_len;
1561
char wbuf[32], hbuf[32];
1562
png_byte bunit = unit;
1564
png_debug(1, "in png_write_sCAL\n");
1566
#if defined(_WIN32_WCE)
1567
/* sprintf() function is not supported on WindowsCE */
1570
swprintf(wc_buf, TEXT("%12.12e"), width);
1571
WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, wbuf, 32, NULL, NULL);
1572
swprintf(wc_buf, TEXT("%12.12e"), height);
1573
WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, hbuf, 32, NULL, NULL);
1576
sprintf(wbuf, "%12.12e", width);
1577
sprintf(hbuf, "%12.12e", height);
1579
total_len = 1 + png_strlen(wbuf)+1 + png_strlen(hbuf);
1581
png_debug1(3, "sCAL total length = %d\n", (int)total_len);
1582
png_write_chunk_start(png_ptr, (png_bytep)png_sCAL, (png_uint_32)total_len);
1583
png_write_chunk_data(png_ptr, (png_bytep)&bunit, 1);
1584
png_write_chunk_data(png_ptr, (png_bytep)wbuf, png_strlen(wbuf)+1);
1585
png_write_chunk_data(png_ptr, (png_bytep)hbuf, png_strlen(hbuf));
1587
png_write_chunk_end(png_ptr);
1590
#ifdef PNG_FIXED_POINT_SUPPORTED
1592
png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
1595
#ifdef PNG_USE_LOCAL_ARRAYS
1598
png_size_t total_len;
1599
char wbuf[32], hbuf[32];
1600
png_byte bunit = unit;
1602
png_debug(1, "in png_write_sCAL_s\n");
1604
png_strcpy(wbuf,(const char *)width);
1605
png_strcpy(hbuf,(const char *)height);
1606
total_len = 1 + png_strlen(wbuf)+1 + png_strlen(hbuf);
1608
png_debug1(3, "sCAL total length = %d\n", total_len);
1609
png_write_chunk_start(png_ptr, (png_bytep)png_sCAL, (png_uint_32)total_len);
1610
png_write_chunk_data(png_ptr, (png_bytep)&bunit, 1);
1611
png_write_chunk_data(png_ptr, (png_bytep)wbuf, png_strlen(wbuf)+1);
1612
png_write_chunk_data(png_ptr, (png_bytep)hbuf, png_strlen(hbuf));
1614
png_write_chunk_end(png_ptr);
1620
#if defined(PNG_WRITE_pHYs_SUPPORTED)
1621
/* write the pHYs chunk */
1623
png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
1624
png_uint_32 y_pixels_per_unit,
1627
#ifdef PNG_USE_LOCAL_ARRAYS
1632
png_debug(1, "in png_write_pHYs\n");
1633
if (unit_type >= PNG_RESOLUTION_LAST)
1634
png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
1636
png_save_uint_32(buf, x_pixels_per_unit);
1637
png_save_uint_32(buf + 4, y_pixels_per_unit);
1638
buf[8] = (png_byte)unit_type;
1640
png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
1644
#if defined(PNG_WRITE_tIME_SUPPORTED)
1645
/* Write the tIME chunk. Use either png_convert_from_struct_tm()
1646
* or png_convert_from_time_t(), or fill in the structure yourself.
1649
png_write_tIME(png_structp png_ptr, png_timep mod_time)
1651
#ifdef PNG_USE_LOCAL_ARRAYS
1656
png_debug(1, "in png_write_tIME\n");
1657
if (mod_time->month > 12 || mod_time->month < 1 ||
1658
mod_time->day > 31 || mod_time->day < 1 ||
1659
mod_time->hour > 23 || mod_time->second > 60)
1661
png_warning(png_ptr, "Invalid time specified for tIME chunk");
1665
png_save_uint_16(buf, mod_time->year);
1666
buf[2] = mod_time->month;
1667
buf[3] = mod_time->day;
1668
buf[4] = mod_time->hour;
1669
buf[5] = mod_time->minute;
1670
buf[6] = mod_time->second;
1672
png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
1676
/* initializes the row writing capability of libpng */
1678
png_write_start_row(png_structp png_ptr)
1680
#ifdef PNG_USE_LOCAL_ARRAYS
1681
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1683
/* start of interlace block */
1684
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1686
/* offset to next interlace block */
1687
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1689
/* start of interlace block in the y direction */
1690
int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1692
/* offset to next interlace block in the y direction */
1693
int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1696
png_size_t buf_size;
1698
png_debug(1, "in png_write_start_row\n");
1699
buf_size = (png_size_t)(PNG_ROWBYTES(
1700
png_ptr->usr_channels*png_ptr->usr_bit_depth,png_ptr->width)+1);
1702
/* set up row buffer */
1703
png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
1704
png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
1706
/* set up filtering buffer, if using this filter */
1707
if (png_ptr->do_filter & PNG_FILTER_SUB)
1709
png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1710
(png_ptr->rowbytes + 1));
1711
png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1714
/* We only need to keep the previous row if we are using one of these. */
1715
if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
1717
/* set up previous row buffer */
1718
png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
1719
png_memset(png_ptr->prev_row, 0, buf_size);
1721
if (png_ptr->do_filter & PNG_FILTER_UP)
1723
png_ptr->up_row = (png_bytep )png_malloc(png_ptr,
1724
(png_ptr->rowbytes + 1));
1725
png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1728
if (png_ptr->do_filter & PNG_FILTER_AVG)
1730
png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1731
(png_ptr->rowbytes + 1));
1732
png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1735
if (png_ptr->do_filter & PNG_FILTER_PAETH)
1737
png_ptr->paeth_row = (png_bytep )png_malloc(png_ptr,
1738
(png_ptr->rowbytes + 1));
1739
png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1743
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1744
/* if interlaced, we need to set up width and height of pass */
1745
if (png_ptr->interlaced)
1747
if (!(png_ptr->transformations & PNG_INTERLACE))
1749
png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
1750
png_pass_ystart[0]) / png_pass_yinc[0];
1751
png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
1752
png_pass_start[0]) / png_pass_inc[0];
1756
png_ptr->num_rows = png_ptr->height;
1757
png_ptr->usr_width = png_ptr->width;
1763
png_ptr->num_rows = png_ptr->height;
1764
png_ptr->usr_width = png_ptr->width;
1766
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1767
png_ptr->zstream.next_out = png_ptr->zbuf;
1770
/* Internal use only. Called when finished processing a row of data. */
1772
png_write_finish_row(png_structp png_ptr)
1774
#ifdef PNG_USE_LOCAL_ARRAYS
1775
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1777
/* start of interlace block */
1778
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1780
/* offset to next interlace block */
1781
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1783
/* start of interlace block in the y direction */
1784
int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1786
/* offset to next interlace block in the y direction */
1787
int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1792
png_debug(1, "in png_write_finish_row\n");
1794
png_ptr->row_number++;
1796
/* see if we are done */
1797
if (png_ptr->row_number < png_ptr->num_rows)
1800
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1801
/* if interlaced, go to next pass */
1802
if (png_ptr->interlaced)
1804
png_ptr->row_number = 0;
1805
if (png_ptr->transformations & PNG_INTERLACE)
1811
/* loop until we find a non-zero width or height pass */
1815
if (png_ptr->pass >= 7)
1817
png_ptr->usr_width = (png_ptr->width +
1818
png_pass_inc[png_ptr->pass] - 1 -
1819
png_pass_start[png_ptr->pass]) /
1820
png_pass_inc[png_ptr->pass];
1821
png_ptr->num_rows = (png_ptr->height +
1822
png_pass_yinc[png_ptr->pass] - 1 -
1823
png_pass_ystart[png_ptr->pass]) /
1824
png_pass_yinc[png_ptr->pass];
1825
if (png_ptr->transformations & PNG_INTERLACE)
1827
} while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
1831
/* reset the row above the image for the next pass */
1832
if (png_ptr->pass < 7)
1834
if (png_ptr->prev_row != NULL)
1835
png_memset(png_ptr->prev_row, 0,
1836
(png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
1837
png_ptr->usr_bit_depth,png_ptr->width))+1);
1843
/* if we get here, we've just written the last row, so we need
1844
to flush the compressor */
1847
/* tell the compressor we are done */
1848
ret = deflate(&png_ptr->zstream, Z_FINISH);
1849
/* check for an error */
1852
/* check to see if we need more room */
1853
if (!(png_ptr->zstream.avail_out))
1855
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
1856
png_ptr->zstream.next_out = png_ptr->zbuf;
1857
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1860
else if (ret != Z_STREAM_END)
1862
if (png_ptr->zstream.msg != NULL)
1863
png_error(png_ptr, png_ptr->zstream.msg);
1865
png_error(png_ptr, "zlib error");
1867
} while (ret != Z_STREAM_END);
1869
/* write any extra space */
1870
if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
1872
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
1873
png_ptr->zstream.avail_out);
1876
deflateReset(&png_ptr->zstream);
1877
png_ptr->zstream.data_type = Z_BINARY;
1880
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
1881
/* Pick out the correct pixels for the interlace pass.
1882
* The basic idea here is to go through the row with a source
1883
* pointer and a destination pointer (sp and dp), and copy the
1884
* correct pixels for the pass. As the row gets compacted,
1885
* sp will always be >= dp, so we should never overwrite anything.
1886
* See the default: case for the easiest code to understand.
1889
png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
1891
#ifdef PNG_USE_LOCAL_ARRAYS
1892
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1894
/* start of interlace block */
1895
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1897
/* offset to next interlace block */
1898
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1901
png_debug(1, "in png_do_write_interlace\n");
1902
/* we don't have to do anything on the last pass (6) */
1903
#if defined(PNG_USELESS_TESTS_SUPPORTED)
1904
if (row != NULL && row_info != NULL && pass < 6)
1909
/* each pixel depth is handled separately */
1910
switch (row_info->pixel_depth)
1920
png_uint_32 row_width = row_info->width;
1925
for (i = png_pass_start[pass]; i < row_width;
1926
i += png_pass_inc[pass])
1928
sp = row + (png_size_t)(i >> 3);
1929
value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
1930
d |= (value << shift);
1935
*dp++ = (png_byte)d;
1954
png_uint_32 row_width = row_info->width;
1959
for (i = png_pass_start[pass]; i < row_width;
1960
i += png_pass_inc[pass])
1962
sp = row + (png_size_t)(i >> 2);
1963
value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
1964
d |= (value << shift);
1969
*dp++ = (png_byte)d;
1987
png_uint_32 row_width = row_info->width;
1992
for (i = png_pass_start[pass]; i < row_width;
1993
i += png_pass_inc[pass])
1995
sp = row + (png_size_t)(i >> 1);
1996
value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
1997
d |= (value << shift);
2002
*dp++ = (png_byte)d;
2017
png_uint_32 row_width = row_info->width;
2018
png_size_t pixel_bytes;
2020
/* start at the beginning */
2022
/* find out how many bytes each pixel takes up */
2023
pixel_bytes = (row_info->pixel_depth >> 3);
2024
/* loop through the row, only looking at the pixels that
2026
for (i = png_pass_start[pass]; i < row_width;
2027
i += png_pass_inc[pass])
2029
/* find out where the original pixel is */
2030
sp = row + (png_size_t)i * pixel_bytes;
2031
/* move the pixel */
2033
png_memcpy(dp, sp, pixel_bytes);
2040
/* set new row width */
2041
row_info->width = (row_info->width +
2042
png_pass_inc[pass] - 1 -
2043
png_pass_start[pass]) /
2045
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
2051
/* This filters the row, chooses which filter to use, if it has not already
2052
* been specified by the application, and then writes the row out with the
2055
#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
2056
#define PNG_HISHIFT 10
2057
#define PNG_LOMASK ((png_uint_32)0xffffL)
2058
#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
2060
png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
2062
png_bytep prev_row, best_row, row_buf;
2063
png_uint_32 mins, bpp;
2064
png_byte filter_to_do = png_ptr->do_filter;
2065
png_uint_32 row_bytes = row_info->rowbytes;
2066
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2067
int num_p_filters = (int)png_ptr->num_prev_filters;
2070
png_debug(1, "in png_write_find_filter\n");
2071
/* find out how many bytes offset each pixel is */
2072
bpp = (row_info->pixel_depth + 7) >> 3;
2074
prev_row = png_ptr->prev_row;
2075
best_row = row_buf = png_ptr->row_buf;
2078
/* The prediction method we use is to find which method provides the
2079
* smallest value when summing the absolute values of the distances
2080
* from zero, using anything >= 128 as negative numbers. This is known
2081
* as the "minimum sum of absolute differences" heuristic. Other
2082
* heuristics are the "weighted minimum sum of absolute differences"
2083
* (experimental and can in theory improve compression), and the "zlib
2084
* predictive" method (not implemented yet), which does test compressions
2085
* of lines using different filter methods, and then chooses the
2086
* (series of) filter(s) that give minimum compressed data size (VERY
2087
* computationally expensive).
2089
* GRR 980525: consider also
2090
* (1) minimum sum of absolute differences from running average (i.e.,
2091
* keep running sum of non-absolute differences & count of bytes)
2092
* [track dispersion, too? restart average if dispersion too large?]
2093
* (1b) minimum sum of absolute differences from sliding average, probably
2094
* with window size <= deflate window (usually 32K)
2095
* (2) minimum sum of squared differences from zero or running average
2096
* (i.e., ~ root-mean-square approach)
2100
/* We don't need to test the 'no filter' case if this is the only filter
2101
* that has been chosen, as it doesn't actually do anything to the data.
2103
if ((filter_to_do & PNG_FILTER_NONE) &&
2104
filter_to_do != PNG_FILTER_NONE)
2107
png_uint_32 sum = 0;
2111
for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
2114
sum += (v < 128) ? v : 256 - v;
2117
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2118
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2120
png_uint_32 sumhi, sumlo;
2122
sumlo = sum & PNG_LOMASK;
2123
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
2125
/* Reduce the sum if we match any of the previous rows */
2126
for (j = 0; j < num_p_filters; j++)
2128
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2130
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2132
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2137
/* Factor in the cost of this filter (this is here for completeness,
2138
* but it makes no sense to have a "cost" for the NONE filter, as
2139
* it has the minimum possible computational cost - none).
2141
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2143
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2146
if (sumhi > PNG_HIMASK)
2149
sum = (sumhi << PNG_HISHIFT) + sumlo;
2156
if (filter_to_do == PNG_FILTER_SUB)
2157
/* it's the only filter so no testing is needed */
2159
png_bytep rp, lp, dp;
2161
for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2166
for (lp = row_buf + 1; i < row_bytes;
2167
i++, rp++, lp++, dp++)
2169
*dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2171
best_row = png_ptr->sub_row;
2174
else if (filter_to_do & PNG_FILTER_SUB)
2176
png_bytep rp, dp, lp;
2177
png_uint_32 sum = 0, lmins = mins;
2181
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2182
/* We temporarily increase the "minimum sum" by the factor we
2183
* would reduce the sum of this filter, so that we can do the
2184
* early exit comparison without scaling the sum each time.
2186
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2189
png_uint_32 lmhi, lmlo;
2190
lmlo = lmins & PNG_LOMASK;
2191
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2193
for (j = 0; j < num_p_filters; j++)
2195
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2197
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2199
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2204
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2206
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2209
if (lmhi > PNG_HIMASK)
2212
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2216
for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2221
sum += (v < 128) ? v : 256 - v;
2223
for (lp = row_buf + 1; i < row_bytes;
2224
i++, rp++, lp++, dp++)
2226
v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2228
sum += (v < 128) ? v : 256 - v;
2230
if (sum > lmins) /* We are already worse, don't continue. */
2234
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2235
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2238
png_uint_32 sumhi, sumlo;
2239
sumlo = sum & PNG_LOMASK;
2240
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2242
for (j = 0; j < num_p_filters; j++)
2244
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2246
sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
2248
sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
2253
sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2255
sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2258
if (sumhi > PNG_HIMASK)
2261
sum = (sumhi << PNG_HISHIFT) + sumlo;
2268
best_row = png_ptr->sub_row;
2273
if (filter_to_do == PNG_FILTER_UP)
2275
png_bytep rp, dp, pp;
2278
for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2279
pp = prev_row + 1; i < row_bytes;
2280
i++, rp++, pp++, dp++)
2282
*dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
2284
best_row = png_ptr->up_row;
2287
else if (filter_to_do & PNG_FILTER_UP)
2289
png_bytep rp, dp, pp;
2290
png_uint_32 sum = 0, lmins = mins;
2295
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2296
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2299
png_uint_32 lmhi, lmlo;
2300
lmlo = lmins & PNG_LOMASK;
2301
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2303
for (j = 0; j < num_p_filters; j++)
2305
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2307
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2309
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2314
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2316
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2319
if (lmhi > PNG_HIMASK)
2322
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2326
for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2327
pp = prev_row + 1; i < row_bytes; i++)
2329
v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2331
sum += (v < 128) ? v : 256 - v;
2333
if (sum > lmins) /* We are already worse, don't continue. */
2337
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2338
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2341
png_uint_32 sumhi, sumlo;
2342
sumlo = sum & PNG_LOMASK;
2343
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2345
for (j = 0; j < num_p_filters; j++)
2347
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2349
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2351
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2356
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2358
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2361
if (sumhi > PNG_HIMASK)
2364
sum = (sumhi << PNG_HISHIFT) + sumlo;
2371
best_row = png_ptr->up_row;
2376
if (filter_to_do == PNG_FILTER_AVG)
2378
png_bytep rp, dp, pp, lp;
2380
for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2381
pp = prev_row + 1; i < bpp; i++)
2383
*dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2385
for (lp = row_buf + 1; i < row_bytes; i++)
2387
*dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
2390
best_row = png_ptr->avg_row;
2393
else if (filter_to_do & PNG_FILTER_AVG)
2395
png_bytep rp, dp, pp, lp;
2396
png_uint_32 sum = 0, lmins = mins;
2400
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2401
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2404
png_uint_32 lmhi, lmlo;
2405
lmlo = lmins & PNG_LOMASK;
2406
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2408
for (j = 0; j < num_p_filters; j++)
2410
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
2412
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2414
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2419
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2421
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2424
if (lmhi > PNG_HIMASK)
2427
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2431
for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2432
pp = prev_row + 1; i < bpp; i++)
2434
v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2436
sum += (v < 128) ? v : 256 - v;
2438
for (lp = row_buf + 1; i < row_bytes; i++)
2441
(png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
2443
sum += (v < 128) ? v : 256 - v;
2445
if (sum > lmins) /* We are already worse, don't continue. */
2449
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2450
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2453
png_uint_32 sumhi, sumlo;
2454
sumlo = sum & PNG_LOMASK;
2455
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2457
for (j = 0; j < num_p_filters; j++)
2459
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2461
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2463
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2468
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2470
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2473
if (sumhi > PNG_HIMASK)
2476
sum = (sumhi << PNG_HISHIFT) + sumlo;
2483
best_row = png_ptr->avg_row;
2488
if (filter_to_do == PNG_FILTER_PAETH)
2490
png_bytep rp, dp, pp, cp, lp;
2492
for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2493
pp = prev_row + 1; i < bpp; i++)
2495
*dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2498
for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2500
int a, b, c, pa, pb, pc, p;
2514
pa = p < 0 ? -p : p;
2515
pb = pc < 0 ? -pc : pc;
2516
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2519
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2521
*dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2523
best_row = png_ptr->paeth_row;
2526
else if (filter_to_do & PNG_FILTER_PAETH)
2528
png_bytep rp, dp, pp, cp, lp;
2529
png_uint_32 sum = 0, lmins = mins;
2533
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2534
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2537
png_uint_32 lmhi, lmlo;
2538
lmlo = lmins & PNG_LOMASK;
2539
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2541
for (j = 0; j < num_p_filters; j++)
2543
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2545
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2547
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2552
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2554
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2557
if (lmhi > PNG_HIMASK)
2560
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2564
for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2565
pp = prev_row + 1; i < bpp; i++)
2567
v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2569
sum += (v < 128) ? v : 256 - v;
2572
for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2574
int a, b, c, pa, pb, pc, p;
2580
#ifndef PNG_SLOW_PAETH
2588
pa = p < 0 ? -p : p;
2589
pb = pc < 0 ? -pc : pc;
2590
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2592
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2593
#else /* PNG_SLOW_PAETH */
2598
if (pa <= pb && pa <= pc)
2604
#endif /* PNG_SLOW_PAETH */
2606
v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2608
sum += (v < 128) ? v : 256 - v;
2610
if (sum > lmins) /* We are already worse, don't continue. */
2614
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2615
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2618
png_uint_32 sumhi, sumlo;
2619
sumlo = sum & PNG_LOMASK;
2620
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2622
for (j = 0; j < num_p_filters; j++)
2624
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2626
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2628
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2633
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2635
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2638
if (sumhi > PNG_HIMASK)
2641
sum = (sumhi << PNG_HISHIFT) + sumlo;
2647
best_row = png_ptr->paeth_row;
2651
/* Do the actual writing of the filtered row data from the chosen filter. */
2653
png_write_filtered_row(png_ptr, best_row);
2655
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2656
/* Save the type of filter we picked this time for future calculations */
2657
if (png_ptr->num_prev_filters > 0)
2660
for (j = 1; j < num_p_filters; j++)
2662
png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
2664
png_ptr->prev_filters[j] = best_row[0];
2670
/* Do the actual writing of a previously filtered row. */
2672
png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
2674
png_debug(1, "in png_write_filtered_row\n");
2675
png_debug1(2, "filter = %d\n", filtered_row[0]);
2676
/* set up the zlib input buffer */
2678
png_ptr->zstream.next_in = filtered_row;
2679
png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
2680
/* repeat until we have compressed all the data */
2683
int ret; /* return of zlib */
2685
/* compress the data */
2686
ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
2687
/* check for compression errors */
2690
if (png_ptr->zstream.msg != NULL)
2691
png_error(png_ptr, png_ptr->zstream.msg);
2693
png_error(png_ptr, "zlib error");
2696
/* see if it is time to write another IDAT */
2697
if (!(png_ptr->zstream.avail_out))
2699
/* write the IDAT and reset the zlib output buffer */
2700
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
2701
png_ptr->zstream.next_out = png_ptr->zbuf;
2702
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
2704
/* repeat until all data has been compressed */
2705
} while (png_ptr->zstream.avail_in);
2707
/* swap the current and previous rows */
2708
if (png_ptr->prev_row != NULL)
2712
tptr = png_ptr->prev_row;
2713
png_ptr->prev_row = png_ptr->row_buf;
2714
png_ptr->row_buf = tptr;
2717
/* finish row - updates counters and flushes zlib if last row */
2718
png_write_finish_row(png_ptr);
2720
#if defined(PNG_WRITE_FLUSH_SUPPORTED)
2721
png_ptr->flush_rows++;
2723
if (png_ptr->flush_dist > 0 &&
2724
png_ptr->flush_rows >= png_ptr->flush_dist)
2726
png_write_flush(png_ptr);
2730
#endif /* PNG_WRITE_SUPPORTED */
added
removed
src/3rdparty/libpng/pngwutil.c
