2
/* pngwutil.c - utilities to write a PNG file
4
* libpng 1.2.5 - October 2, 2002
5
* For conditions of distribution and use, see copyright notice in png.h
6
* Copyright (c) 1998-2002 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
31
* 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;
139
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
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* 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.
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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)
180
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.
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* 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
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* 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 */
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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() */
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/* 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 && png_ptr->zstream.avail_in)
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 * sizeof (png_charpp)));
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png_memcpy(comp->output_ptr, old_ptr, old_max
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* sizeof (png_charp));
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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 * 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 */
255
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
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png_ptr->zstream.next_out = png_ptr->zbuf;
258
/* continue until we don't have any more to compress */
259
} while (png_ptr->zstream.avail_in);
261
/* finish the compression */
264
/* tell zlib we are finished */
265
ret = deflate(&png_ptr->zstream, Z_FINISH);
269
/* check to see if we need more room */
270
if (!(png_ptr->zstream.avail_out))
272
/* check to make sure our output array has room */
273
if (comp->num_output_ptr >= comp->max_output_ptr)
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old_max = comp->max_output_ptr;
278
comp->max_output_ptr = comp->num_output_ptr + 4;
279
if (comp->output_ptr != NULL)
283
old_ptr = comp->output_ptr;
284
/* This could be optimized to realloc() */
285
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
286
(png_uint_32)(comp->max_output_ptr * sizeof (png_charpp)));
287
png_memcpy(comp->output_ptr, old_ptr,
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old_max * sizeof (png_charp));
289
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 * sizeof (png_charp)));
296
/* save off the data */
297
comp->output_ptr[comp->num_output_ptr] =
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(png_charp)png_malloc(png_ptr, (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 pointers */
304
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
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png_ptr->zstream.next_out = png_ptr->zbuf;
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else if (ret != Z_STREAM_END)
310
/* we got an error */
311
if (png_ptr->zstream.msg != NULL)
312
png_error(png_ptr, png_ptr->zstream.msg);
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png_error(png_ptr, "zlib error");
316
} while (ret != Z_STREAM_END);
318
/* text length is number of buffers plus last buffer */
319
text_len = png_ptr->zbuf_size * comp->num_output_ptr;
320
if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
321
text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
323
return((int)text_len);
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/* ship the compressed text out via chunk writes */
327
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 */
335
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)
349
png_free(png_ptr, comp->output_ptr);
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comp->output_ptr=NULL;
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/* write anything left in zbuf */
352
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 the image data */
357
deflateReset(&png_ptr->zstream);
362
/* Write the IHDR chunk, and update the png_struct with the necessary
363
* information. Note that the rest of this code depends upon this
364
* information being correct.
367
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,
371
#ifdef PNG_USE_LOCAL_ARRAYS
374
png_byte buf[13]; /* buffer to store the IHDR info */
376
png_debug(1, "in png_write_IHDR\n");
377
/* Check that we have valid input data from the application info */
380
case PNG_COLOR_TYPE_GRAY:
387
case 16: png_ptr->channels = 1; break;
388
default: png_error(png_ptr,"Invalid bit depth for grayscale image");
391
case PNG_COLOR_TYPE_RGB:
392
if (bit_depth != 8 && bit_depth != 16)
393
png_error(png_ptr, "Invalid bit depth for RGB image");
394
png_ptr->channels = 3;
396
case PNG_COLOR_TYPE_PALETTE:
402
case 8: png_ptr->channels = 1; break;
403
default: png_error(png_ptr, "Invalid bit depth for paletted image");
406
case PNG_COLOR_TYPE_GRAY_ALPHA:
407
if (bit_depth != 8 && bit_depth != 16)
408
png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
409
png_ptr->channels = 2;
411
case PNG_COLOR_TYPE_RGB_ALPHA:
412
if (bit_depth != 8 && bit_depth != 16)
413
png_error(png_ptr, "Invalid bit depth for RGBA image");
414
png_ptr->channels = 4;
417
png_error(png_ptr, "Invalid image color type specified");
420
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
422
png_warning(png_ptr, "Invalid compression type specified");
423
compression_type = PNG_COMPRESSION_TYPE_BASE;
426
/* Write filter_method 64 (intrapixel differencing) only if
427
* 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
428
* 2. Libpng did not write a PNG signature (this filter_method is only
429
* used in PNG datastreams that are embedded in MNG datastreams) and
430
* 3. The application called png_permit_mng_features with a mask that
431
* included PNG_FLAG_MNG_FILTER_64 and
432
* 4. The filter_method is 64 and
433
* 5. The color_type is RGB or RGBA
436
#if defined(PNG_MNG_FEATURES_SUPPORTED)
437
!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
438
((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
439
(color_type == PNG_COLOR_TYPE_RGB ||
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color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
441
(filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
443
filter_type != PNG_FILTER_TYPE_BASE)
445
png_warning(png_ptr, "Invalid filter type specified");
446
filter_type = PNG_FILTER_TYPE_BASE;
449
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
450
if (interlace_type != PNG_INTERLACE_NONE &&
451
interlace_type != PNG_INTERLACE_ADAM7)
453
png_warning(png_ptr, "Invalid interlace type specified");
454
interlace_type = PNG_INTERLACE_ADAM7;
457
interlace_type=PNG_INTERLACE_NONE;
460
/* save off the relevent information */
461
png_ptr->bit_depth = (png_byte)bit_depth;
462
png_ptr->color_type = (png_byte)color_type;
463
png_ptr->interlaced = (png_byte)interlace_type;
464
#if defined(PNG_MNG_FEATURES_SUPPORTED)
465
png_ptr->filter_type = (png_byte)filter_type;
467
png_ptr->width = width;
468
png_ptr->height = height;
470
png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
471
png_ptr->rowbytes = ((width * (png_size_t)png_ptr->pixel_depth + 7) >> 3);
472
/* set the usr info, so any transformations can modify it */
473
png_ptr->usr_width = png_ptr->width;
474
png_ptr->usr_bit_depth = png_ptr->bit_depth;
475
png_ptr->usr_channels = png_ptr->channels;
477
/* pack the header information into the buffer */
478
png_save_uint_32(buf, width);
479
png_save_uint_32(buf + 4, height);
480
buf[8] = (png_byte)bit_depth;
481
buf[9] = (png_byte)color_type;
482
buf[10] = (png_byte)compression_type;
483
buf[11] = (png_byte)filter_type;
484
buf[12] = (png_byte)interlace_type;
486
/* write the chunk */
487
png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
489
/* initialize zlib with PNG info */
490
png_ptr->zstream.zalloc = png_zalloc;
491
png_ptr->zstream.zfree = png_zfree;
492
png_ptr->zstream.opaque = (voidpf)png_ptr;
493
if (!(png_ptr->do_filter))
495
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
496
png_ptr->bit_depth < 8)
497
png_ptr->do_filter = PNG_FILTER_NONE;
499
png_ptr->do_filter = PNG_ALL_FILTERS;
501
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
503
if (png_ptr->do_filter != PNG_FILTER_NONE)
504
png_ptr->zlib_strategy = Z_FILTERED;
506
png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
508
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
509
png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
510
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
511
png_ptr->zlib_mem_level = 8;
512
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
513
png_ptr->zlib_window_bits = 15;
514
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
515
png_ptr->zlib_method = 8;
516
deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
517
png_ptr->zlib_method, png_ptr->zlib_window_bits,
518
png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
519
png_ptr->zstream.next_out = png_ptr->zbuf;
520
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
522
png_ptr->mode = PNG_HAVE_IHDR;
525
/* write the palette. We are careful not to trust png_color to be in the
526
* correct order for PNG, so people can redefine it to any convenient
530
png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
532
#ifdef PNG_USE_LOCAL_ARRAYS
539
png_debug(1, "in png_write_PLTE\n");
541
#if defined(PNG_MNG_FEATURES_SUPPORTED)
542
!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
544
num_pal == 0) || num_pal > 256)
546
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
548
png_error(png_ptr, "Invalid number of colors in palette");
552
png_warning(png_ptr, "Invalid number of colors in palette");
557
if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
560
"Ignoring request to write a PLTE chunk in grayscale PNG");
564
png_ptr->num_palette = (png_uint_16)num_pal;
565
png_debug1(3, "num_palette = %d\n", png_ptr->num_palette);
567
png_write_chunk_start(png_ptr, (png_bytep)png_PLTE, num_pal * 3);
568
#ifndef PNG_NO_POINTER_INDEXING
569
for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
571
buf[0] = pal_ptr->red;
572
buf[1] = pal_ptr->green;
573
buf[2] = pal_ptr->blue;
574
png_write_chunk_data(png_ptr, buf, (png_size_t)3);
577
/* This is a little slower but some buggy compilers need to do this instead */
579
for (i = 0; i < num_pal; i++)
581
buf[0] = pal_ptr[i].red;
582
buf[1] = pal_ptr[i].green;
583
buf[2] = pal_ptr[i].blue;
584
png_write_chunk_data(png_ptr, buf, (png_size_t)3);
587
png_write_chunk_end(png_ptr);
588
png_ptr->mode |= PNG_HAVE_PLTE;
591
/* write an IDAT chunk */
593
png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
595
#ifdef PNG_USE_LOCAL_ARRAYS
598
png_debug(1, "in png_write_IDAT\n");
599
png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
600
png_ptr->mode |= PNG_HAVE_IDAT;
603
/* write an IEND chunk */
605
png_write_IEND(png_structp png_ptr)
607
#ifdef PNG_USE_LOCAL_ARRAYS
610
png_debug(1, "in png_write_IEND\n");
611
png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,
613
png_ptr->mode |= PNG_HAVE_IEND;
616
#if defined(PNG_WRITE_gAMA_SUPPORTED)
617
/* write a gAMA chunk */
618
#ifdef PNG_FLOATING_POINT_SUPPORTED
620
png_write_gAMA(png_structp png_ptr, double file_gamma)
622
#ifdef PNG_USE_LOCAL_ARRAYS
628
png_debug(1, "in png_write_gAMA\n");
629
/* file_gamma is saved in 1/100,000ths */
630
igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
631
png_save_uint_32(buf, igamma);
632
png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
635
#ifdef PNG_FIXED_POINT_SUPPORTED
637
png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
639
#ifdef PNG_USE_LOCAL_ARRAYS
644
png_debug(1, "in png_write_gAMA\n");
645
/* file_gamma is saved in 1/100,000ths */
646
png_save_uint_32(buf, (png_uint_32)file_gamma);
647
png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
652
#if defined(PNG_WRITE_sRGB_SUPPORTED)
653
/* write a sRGB chunk */
655
png_write_sRGB(png_structp png_ptr, int srgb_intent)
657
#ifdef PNG_USE_LOCAL_ARRAYS
662
png_debug(1, "in png_write_sRGB\n");
663
if(srgb_intent >= PNG_sRGB_INTENT_LAST)
665
"Invalid sRGB rendering intent specified");
666
buf[0]=(png_byte)srgb_intent;
667
png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
671
#if defined(PNG_WRITE_iCCP_SUPPORTED)
672
/* write an iCCP chunk */
674
png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
675
png_charp profile, int profile_len)
677
#ifdef PNG_USE_LOCAL_ARRAYS
682
compression_state comp;
684
png_debug(1, "in png_write_iCCP\n");
685
if (name == NULL || (name_len = png_check_keyword(png_ptr, name,
688
png_warning(png_ptr, "Empty keyword in iCCP chunk");
692
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
693
png_warning(png_ptr, "Unknown compression type in iCCP chunk");
699
profile_len = png_text_compress(png_ptr, profile, (png_size_t)profile_len,
700
PNG_COMPRESSION_TYPE_BASE, &comp);
702
/* make sure we include the NULL after the name and the compression type */
703
png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
704
(png_uint_32)name_len+profile_len+2);
705
new_name[name_len+1]=0x00;
706
png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 2);
709
png_write_compressed_data_out(png_ptr, &comp);
711
png_write_chunk_end(png_ptr);
712
png_free(png_ptr, new_name);
716
#if defined(PNG_WRITE_sPLT_SUPPORTED)
717
/* write a sPLT chunk */
719
png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
721
#ifdef PNG_USE_LOCAL_ARRAYS
726
png_byte entrybuf[10];
727
int entry_size = (spalette->depth == 8 ? 6 : 10);
728
int palette_size = entry_size * spalette->nentries;
730
#ifdef PNG_NO_POINTER_INDEXING
734
png_debug(1, "in png_write_sPLT\n");
735
if (spalette->name == NULL || (name_len = png_check_keyword(png_ptr,
736
spalette->name, &new_name))==0)
738
png_warning(png_ptr, "Empty keyword in sPLT chunk");
742
/* make sure we include the NULL after the name */
743
png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
744
(png_uint_32)(name_len + 2 + palette_size));
745
png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 1);
746
png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, 1);
748
/* loop through each palette entry, writing appropriately */
749
#ifndef PNG_NO_POINTER_INDEXING
750
for (ep = spalette->entries; ep<spalette->entries+spalette->nentries; ep++)
752
if (spalette->depth == 8)
754
entrybuf[0] = (png_byte)ep->red;
755
entrybuf[1] = (png_byte)ep->green;
756
entrybuf[2] = (png_byte)ep->blue;
757
entrybuf[3] = (png_byte)ep->alpha;
758
png_save_uint_16(entrybuf + 4, ep->frequency);
762
png_save_uint_16(entrybuf + 0, ep->red);
763
png_save_uint_16(entrybuf + 2, ep->green);
764
png_save_uint_16(entrybuf + 4, ep->blue);
765
png_save_uint_16(entrybuf + 6, ep->alpha);
766
png_save_uint_16(entrybuf + 8, ep->frequency);
768
png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
771
ep=spalette->entries;
772
for (i=0; i>spalette->nentries; i++)
774
if (spalette->depth == 8)
776
entrybuf[0] = (png_byte)ep[i].red;
777
entrybuf[1] = (png_byte)ep[i].green;
778
entrybuf[2] = (png_byte)ep[i].blue;
779
entrybuf[3] = (png_byte)ep[i].alpha;
780
png_save_uint_16(entrybuf + 4, ep[i].frequency);
784
png_save_uint_16(entrybuf + 0, ep[i].red);
785
png_save_uint_16(entrybuf + 2, ep[i].green);
786
png_save_uint_16(entrybuf + 4, ep[i].blue);
787
png_save_uint_16(entrybuf + 6, ep[i].alpha);
788
png_save_uint_16(entrybuf + 8, ep[i].frequency);
790
png_write_chunk_data(png_ptr, entrybuf, entry_size);
794
png_write_chunk_end(png_ptr);
795
png_free(png_ptr, new_name);
799
#if defined(PNG_WRITE_sBIT_SUPPORTED)
800
/* write the sBIT chunk */
802
png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
804
#ifdef PNG_USE_LOCAL_ARRAYS
810
png_debug(1, "in png_write_sBIT\n");
811
/* make sure we don't depend upon the order of PNG_COLOR_8 */
812
if (color_type & PNG_COLOR_MASK_COLOR)
816
maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
817
png_ptr->usr_bit_depth);
818
if (sbit->red == 0 || sbit->red > maxbits ||
819
sbit->green == 0 || sbit->green > maxbits ||
820
sbit->blue == 0 || sbit->blue > maxbits)
822
png_warning(png_ptr, "Invalid sBIT depth specified");
826
buf[1] = sbit->green;
832
if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
834
png_warning(png_ptr, "Invalid sBIT depth specified");
841
if (color_type & PNG_COLOR_MASK_ALPHA)
843
if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
845
png_warning(png_ptr, "Invalid sBIT depth specified");
848
buf[size++] = sbit->alpha;
851
png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
855
#if defined(PNG_WRITE_cHRM_SUPPORTED)
856
/* write the cHRM chunk */
857
#ifdef PNG_FLOATING_POINT_SUPPORTED
859
png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
860
double red_x, double red_y, double green_x, double green_y,
861
double blue_x, double blue_y)
863
#ifdef PNG_USE_LOCAL_ARRAYS
869
png_debug(1, "in png_write_cHRM\n");
870
/* each value is saved in 1/100,000ths */
871
if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 ||
872
white_x + white_y > 1.0)
874
png_warning(png_ptr, "Invalid cHRM white point specified");
875
#if !defined(PNG_NO_CONSOLE_IO)
876
fprintf(stderr,"white_x=%f, white_y=%f\n",white_x, white_y);
880
itemp = (png_uint_32)(white_x * 100000.0 + 0.5);
881
png_save_uint_32(buf, itemp);
882
itemp = (png_uint_32)(white_y * 100000.0 + 0.5);
883
png_save_uint_32(buf + 4, itemp);
885
if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 ||
888
png_warning(png_ptr, "Invalid cHRM red point specified");
891
itemp = (png_uint_32)(red_x * 100000.0 + 0.5);
892
png_save_uint_32(buf + 8, itemp);
893
itemp = (png_uint_32)(red_y * 100000.0 + 0.5);
894
png_save_uint_32(buf + 12, itemp);
896
if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 ||
897
green_x + green_y > 1.0)
899
png_warning(png_ptr, "Invalid cHRM green point specified");
902
itemp = (png_uint_32)(green_x * 100000.0 + 0.5);
903
png_save_uint_32(buf + 16, itemp);
904
itemp = (png_uint_32)(green_y * 100000.0 + 0.5);
905
png_save_uint_32(buf + 20, itemp);
907
if (blue_x < 0 || blue_x > 0.8 || blue_y < 0 || blue_y > 0.8 ||
908
blue_x + blue_y > 1.0)
910
png_warning(png_ptr, "Invalid cHRM blue point specified");
913
itemp = (png_uint_32)(blue_x * 100000.0 + 0.5);
914
png_save_uint_32(buf + 24, itemp);
915
itemp = (png_uint_32)(blue_y * 100000.0 + 0.5);
916
png_save_uint_32(buf + 28, itemp);
918
png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
921
#ifdef PNG_FIXED_POINT_SUPPORTED
923
png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
924
png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
925
png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
926
png_fixed_point blue_y)
928
#ifdef PNG_USE_LOCAL_ARRAYS
933
png_debug(1, "in png_write_cHRM\n");
934
/* each value is saved in 1/100,000ths */
935
if (white_x > 80000L || white_y > 80000L || white_x + white_y > 100000L)
937
png_warning(png_ptr, "Invalid fixed cHRM white point specified");
938
#if !defined(PNG_NO_CONSOLE_IO)
939
fprintf(stderr,"white_x=%ld, white_y=%ld\n",white_x, white_y);
943
png_save_uint_32(buf, (png_uint_32)white_x);
944
png_save_uint_32(buf + 4, (png_uint_32)white_y);
946
if (red_x > 80000L || red_y > 80000L || red_x + red_y > 100000L)
948
png_warning(png_ptr, "Invalid cHRM fixed red point specified");
951
png_save_uint_32(buf + 8, (png_uint_32)red_x);
952
png_save_uint_32(buf + 12, (png_uint_32)red_y);
954
if (green_x > 80000L || green_y > 80000L || green_x + green_y > 100000L)
956
png_warning(png_ptr, "Invalid fixed cHRM green point specified");
959
png_save_uint_32(buf + 16, (png_uint_32)green_x);
960
png_save_uint_32(buf + 20, (png_uint_32)green_y);
962
if (blue_x > 80000L || blue_y > 80000L || blue_x + blue_y > 100000L)
964
png_warning(png_ptr, "Invalid fixed cHRM blue point specified");
967
png_save_uint_32(buf + 24, (png_uint_32)blue_x);
968
png_save_uint_32(buf + 28, (png_uint_32)blue_y);
970
png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
975
#if defined(PNG_WRITE_tRNS_SUPPORTED)
976
/* write the tRNS chunk */
978
png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
979
int num_trans, int color_type)
981
#ifdef PNG_USE_LOCAL_ARRAYS
986
png_debug(1, "in png_write_tRNS\n");
987
if (color_type == PNG_COLOR_TYPE_PALETTE)
989
if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
991
png_warning(png_ptr,"Invalid number of transparent colors specified");
994
/* write the chunk out as it is */
995
png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans, (png_size_t)num_trans);
997
else if (color_type == PNG_COLOR_TYPE_GRAY)
999
/* one 16 bit value */
1000
if(tran->gray >= (1 << png_ptr->bit_depth))
1002
png_warning(png_ptr,
1003
"Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
1006
png_save_uint_16(buf, tran->gray);
1007
png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
1009
else if (color_type == PNG_COLOR_TYPE_RGB)
1011
/* three 16 bit values */
1012
png_save_uint_16(buf, tran->red);
1013
png_save_uint_16(buf + 2, tran->green);
1014
png_save_uint_16(buf + 4, tran->blue);
1015
if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1017
png_warning(png_ptr,
1018
"Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
1021
png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
1025
png_warning(png_ptr, "Can't write tRNS with an alpha channel");
1030
#if defined(PNG_WRITE_bKGD_SUPPORTED)
1031
/* write the background chunk */
1033
png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
1035
#ifdef PNG_USE_LOCAL_ARRAYS
1040
png_debug(1, "in png_write_bKGD\n");
1041
if (color_type == PNG_COLOR_TYPE_PALETTE)
1044
#if defined(PNG_MNG_FEATURES_SUPPORTED)
1045
(png_ptr->num_palette ||
1046
(!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
1048
back->index > png_ptr->num_palette)
1050
png_warning(png_ptr, "Invalid background palette index");
1053
buf[0] = back->index;
1054
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
1056
else if (color_type & PNG_COLOR_MASK_COLOR)
1058
png_save_uint_16(buf, back->red);
1059
png_save_uint_16(buf + 2, back->green);
1060
png_save_uint_16(buf + 4, back->blue);
1061
if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
1063
png_warning(png_ptr,
1064
"Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
1067
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
1071
if(back->gray >= (1 << png_ptr->bit_depth))
1073
png_warning(png_ptr,
1074
"Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
1077
png_save_uint_16(buf, back->gray);
1078
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
1083
#if defined(PNG_WRITE_hIST_SUPPORTED)
1084
/* write the histogram */
1086
png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
1088
#ifdef PNG_USE_LOCAL_ARRAYS
1094
png_debug(1, "in png_write_hIST\n");
1095
if (num_hist > (int)png_ptr->num_palette)
1097
png_debug2(3, "num_hist = %d, num_palette = %d\n", num_hist,
1098
png_ptr->num_palette);
1099
png_warning(png_ptr, "Invalid number of histogram entries specified");
1103
png_write_chunk_start(png_ptr, (png_bytep)png_hIST, (png_uint_32)(num_hist * 2));
1104
for (i = 0; i < num_hist; i++)
1106
png_save_uint_16(buf, hist[i]);
1107
png_write_chunk_data(png_ptr, buf, (png_size_t)2);
1109
png_write_chunk_end(png_ptr);
1113
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
1114
defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
1115
/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
1116
* and if invalid, correct the keyword rather than discarding the entire
1117
* chunk. The PNG 1.0 specification requires keywords 1-79 characters in
1118
* length, forbids leading or trailing whitespace, multiple internal spaces,
1119
* and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
1121
* The new_key is allocated to hold the corrected keyword and must be freed
1122
* by the calling routine. This avoids problems with trying to write to
1123
* static keywords without having to have duplicate copies of the strings.
1125
png_size_t /* PRIVATE */
1126
png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
1133
png_debug(1, "in png_check_keyword\n");
1136
if (key == NULL || (key_len = png_strlen(key)) == 0)
1138
png_warning(png_ptr, "zero length keyword");
1139
return ((png_size_t)0);
1142
png_debug1(2, "Keyword to be checked is '%s'\n", key);
1144
*new_key = (png_charp)png_malloc(png_ptr, (png_uint_32)(key_len + 2));
1146
/* Replace non-printing characters with a blank and print a warning */
1147
for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
1149
if (*kp < 0x20 || (*kp > 0x7E && (png_byte)*kp < 0xA1))
1151
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
1154
sprintf(msg, "invalid keyword character 0x%02X", *kp);
1155
png_warning(png_ptr, msg);
1157
png_warning(png_ptr, "invalid character in keyword");
1168
/* Remove any trailing white space. */
1169
kp = *new_key + key_len - 1;
1172
png_warning(png_ptr, "trailing spaces removed from keyword");
1181
/* Remove any leading white space. */
1185
png_warning(png_ptr, "leading spaces removed from keyword");
1194
png_debug1(2, "Checking for multiple internal spaces in '%s'\n", kp);
1196
/* Remove multiple internal spaces. */
1197
for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
1199
if (*kp == ' ' && kflag == 0)
1204
else if (*kp == ' ')
1217
png_warning(png_ptr, "extra interior spaces removed from keyword");
1221
png_free(png_ptr, *new_key);
1223
png_warning(png_ptr, "Zero length keyword");
1228
png_warning(png_ptr, "keyword length must be 1 - 79 characters");
1237
#if defined(PNG_WRITE_tEXt_SUPPORTED)
1238
/* write a tEXt chunk */
1240
png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
1241
png_size_t text_len)
1243
#ifdef PNG_USE_LOCAL_ARRAYS
1249
png_debug(1, "in png_write_tEXt\n");
1250
if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1252
png_warning(png_ptr, "Empty keyword in tEXt chunk");
1256
if (text == NULL || *text == '\0')
1259
text_len = png_strlen(text);
1261
/* make sure we include the 0 after the key */
1262
png_write_chunk_start(png_ptr, (png_bytep)png_tEXt, (png_uint_32)key_len+text_len+1);
1264
* We leave it to the application to meet PNG-1.0 requirements on the
1265
* contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1266
* any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1267
* The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1269
png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
1271
png_write_chunk_data(png_ptr, (png_bytep)text, text_len);
1273
png_write_chunk_end(png_ptr);
1274
png_free(png_ptr, new_key);
1278
#if defined(PNG_WRITE_zTXt_SUPPORTED)
1279
/* write a compressed text chunk */
1281
png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
1282
png_size_t text_len, int compression)
1284
#ifdef PNG_USE_LOCAL_ARRAYS
1290
compression_state comp;
1292
png_debug(1, "in png_write_zTXt\n");
1294
if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1296
png_warning(png_ptr, "Empty keyword in zTXt chunk");
1300
if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
1302
png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
1303
png_free(png_ptr, new_key);
1307
text_len = png_strlen(text);
1309
png_free(png_ptr, new_key);
1311
/* compute the compressed data; do it now for the length */
1312
text_len = png_text_compress(png_ptr, text, text_len, compression,
1315
/* write start of chunk */
1316
png_write_chunk_start(png_ptr, (png_bytep)png_zTXt, (png_uint_32)
1317
(key_len+text_len+2));
1319
png_write_chunk_data(png_ptr, (png_bytep)key, key_len + 1);
1320
buf[0] = (png_byte)compression;
1321
/* write compression */
1322
png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);
1323
/* write the compressed data */
1324
png_write_compressed_data_out(png_ptr, &comp);
1326
/* close the chunk */
1327
png_write_chunk_end(png_ptr);
1331
#if defined(PNG_WRITE_iTXt_SUPPORTED)
1332
/* write an iTXt chunk */
1334
png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
1335
png_charp lang, png_charp lang_key, png_charp text)
1337
#ifdef PNG_USE_LOCAL_ARRAYS
1340
png_size_t lang_len, key_len, lang_key_len, text_len;
1341
png_charp new_lang, new_key;
1343
compression_state comp;
1345
png_debug(1, "in png_write_iTXt\n");
1347
if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1349
png_warning(png_ptr, "Empty keyword in iTXt chunk");
1352
if (lang == NULL || (lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
1354
png_warning(png_ptr, "Empty language field in iTXt chunk");
1359
if (lang_key == NULL)
1362
lang_key_len = png_strlen(lang_key);
1367
text_len = png_strlen(text);
1369
/* compute the compressed data; do it now for the length */
1370
text_len = png_text_compress(png_ptr, text, text_len, compression-2,
1374
/* make sure we include the compression flag, the compression byte,
1375
* and the NULs after the key, lang, and lang_key parts */
1377
png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
1379
5 /* comp byte, comp flag, terminators for key, lang and lang_key */
1386
* We leave it to the application to meet PNG-1.0 requirements on the
1387
* contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
1388
* any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
1389
* The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1391
png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
1393
/* set the compression flag */
1394
if (compression == PNG_ITXT_COMPRESSION_NONE || \
1395
compression == PNG_TEXT_COMPRESSION_NONE)
1397
else /* compression == PNG_ITXT_COMPRESSION_zTXt */
1399
/* set the compression method */
1401
png_write_chunk_data(png_ptr, cbuf, 2);
1404
png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf), lang_len + 1);
1405
png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf), lang_key_len + 1);
1406
png_write_compressed_data_out(png_ptr, &comp);
1408
png_write_chunk_end(png_ptr);
1409
png_free(png_ptr, new_key);
1411
png_free(png_ptr, new_lang);
1415
#if defined(PNG_WRITE_oFFs_SUPPORTED)
1416
/* write the oFFs chunk */
1418
png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
1421
#ifdef PNG_USE_LOCAL_ARRAYS
1426
png_debug(1, "in png_write_oFFs\n");
1427
if (unit_type >= PNG_OFFSET_LAST)
1428
png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
1430
png_save_int_32(buf, x_offset);
1431
png_save_int_32(buf + 4, y_offset);
1432
buf[8] = (png_byte)unit_type;
1434
png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
1438
#if defined(PNG_WRITE_pCAL_SUPPORTED)
1439
/* write the pCAL chunk (described in the PNG extensions document) */
1441
png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
1442
png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
1444
#ifdef PNG_USE_LOCAL_ARRAYS
1447
png_size_t purpose_len, units_len, total_len;
1448
png_uint_32p params_len;
1450
png_charp new_purpose;
1453
png_debug1(1, "in png_write_pCAL (%d parameters)\n", nparams);
1454
if (type >= PNG_EQUATION_LAST)
1455
png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
1457
purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
1458
png_debug1(3, "pCAL purpose length = %d\n", (int)purpose_len);
1459
units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
1460
png_debug1(3, "pCAL units length = %d\n", (int)units_len);
1461
total_len = purpose_len + units_len + 10;
1463
params_len = (png_uint_32p)png_malloc(png_ptr, (png_uint_32)(nparams
1464
*sizeof(png_uint_32)));
1466
/* Find the length of each parameter, making sure we don't count the
1467
null terminator for the last parameter. */
1468
for (i = 0; i < nparams; i++)
1470
params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
1471
png_debug2(3, "pCAL parameter %d length = %lu\n", i, params_len[i]);
1472
total_len += (png_size_t)params_len[i];
1475
png_debug1(3, "pCAL total length = %d\n", (int)total_len);
1476
png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
1477
png_write_chunk_data(png_ptr, (png_bytep)new_purpose, purpose_len);
1478
png_save_int_32(buf, X0);
1479
png_save_int_32(buf + 4, X1);
1480
buf[8] = (png_byte)type;
1481
buf[9] = (png_byte)nparams;
1482
png_write_chunk_data(png_ptr, buf, (png_size_t)10);
1483
png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);
1485
png_free(png_ptr, new_purpose);
1487
for (i = 0; i < nparams; i++)
1489
png_write_chunk_data(png_ptr, (png_bytep)params[i],
1490
(png_size_t)params_len[i]);
1493
png_free(png_ptr, params_len);
1494
png_write_chunk_end(png_ptr);
1498
#if defined(PNG_WRITE_sCAL_SUPPORTED)
1499
/* write the sCAL chunk */
1500
#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
1502
png_write_sCAL(png_structp png_ptr, int unit, double width,double height)
1504
#ifdef PNG_USE_LOCAL_ARRAYS
1507
png_size_t total_len;
1508
char wbuf[32], hbuf[32];
1510
png_debug(1, "in png_write_sCAL\n");
1512
#if defined(_WIN32_WCE)
1513
/* sprintf() function is not supported on WindowsCE */
1516
swprintf(wc_buf, TEXT("%12.12e"), width);
1517
WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, wbuf, 32, NULL, NULL);
1518
swprintf(wc_buf, TEXT("%12.12e"), height);
1519
WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, hbuf, 32, NULL, NULL);
1522
sprintf(wbuf, "%12.12e", width);
1523
sprintf(hbuf, "%12.12e", height);
1525
total_len = 1 + png_strlen(wbuf)+1 + png_strlen(hbuf);
1527
png_debug1(3, "sCAL total length = %d\n", (int)total_len);
1528
png_write_chunk_start(png_ptr, (png_bytep)png_sCAL, (png_uint_32)total_len);
1529
png_write_chunk_data(png_ptr, (png_bytep)&unit, 1);
1530
png_write_chunk_data(png_ptr, (png_bytep)wbuf, png_strlen(wbuf)+1);
1531
png_write_chunk_data(png_ptr, (png_bytep)hbuf, png_strlen(hbuf));
1533
png_write_chunk_end(png_ptr);
1536
#ifdef PNG_FIXED_POINT_SUPPORTED
1538
png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
1541
#ifdef PNG_USE_LOCAL_ARRAYS
1544
png_size_t total_len;
1545
char wbuf[32], hbuf[32];
1547
png_debug(1, "in png_write_sCAL_s\n");
1549
png_strcpy(wbuf,(const char *)width);
1550
png_strcpy(hbuf,(const char *)height);
1551
total_len = 1 + png_strlen(wbuf)+1 + png_strlen(hbuf);
1553
png_debug1(3, "sCAL total length = %d\n", total_len);
1554
png_write_chunk_start(png_ptr, (png_bytep)png_sCAL, (png_uint_32)total_len);
1555
png_write_chunk_data(png_ptr, (png_bytep)&unit, 1);
1556
png_write_chunk_data(png_ptr, (png_bytep)wbuf, png_strlen(wbuf)+1);
1557
png_write_chunk_data(png_ptr, (png_bytep)hbuf, png_strlen(hbuf));
1559
png_write_chunk_end(png_ptr);
1565
#if defined(PNG_WRITE_pHYs_SUPPORTED)
1566
/* write the pHYs chunk */
1568
png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
1569
png_uint_32 y_pixels_per_unit,
1572
#ifdef PNG_USE_LOCAL_ARRAYS
1577
png_debug(1, "in png_write_pHYs\n");
1578
if (unit_type >= PNG_RESOLUTION_LAST)
1579
png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
1581
png_save_uint_32(buf, x_pixels_per_unit);
1582
png_save_uint_32(buf + 4, y_pixels_per_unit);
1583
buf[8] = (png_byte)unit_type;
1585
png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
1589
#if defined(PNG_WRITE_tIME_SUPPORTED)
1590
/* Write the tIME chunk. Use either png_convert_from_struct_tm()
1591
* or png_convert_from_time_t(), or fill in the structure yourself.
1594
png_write_tIME(png_structp png_ptr, png_timep mod_time)
1596
#ifdef PNG_USE_LOCAL_ARRAYS
1601
png_debug(1, "in png_write_tIME\n");
1602
if (mod_time->month > 12 || mod_time->month < 1 ||
1603
mod_time->day > 31 || mod_time->day < 1 ||
1604
mod_time->hour > 23 || mod_time->second > 60)
1606
png_warning(png_ptr, "Invalid time specified for tIME chunk");
1610
png_save_uint_16(buf, mod_time->year);
1611
buf[2] = mod_time->month;
1612
buf[3] = mod_time->day;
1613
buf[4] = mod_time->hour;
1614
buf[5] = mod_time->minute;
1615
buf[6] = mod_time->second;
1617
png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
1621
/* initializes the row writing capability of libpng */
1623
png_write_start_row(png_structp png_ptr)
1625
#ifdef PNG_USE_LOCAL_ARRAYS
1626
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1628
/* start of interlace block */
1629
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1631
/* offset to next interlace block */
1632
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1634
/* start of interlace block in the y direction */
1635
int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1637
/* offset to next interlace block in the y direction */
1638
int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1641
png_size_t buf_size;
1643
png_debug(1, "in png_write_start_row\n");
1644
buf_size = (png_size_t)(((png_ptr->width * png_ptr->usr_channels *
1645
png_ptr->usr_bit_depth + 7) >> 3) + 1);
1647
/* set up row buffer */
1648
png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
1649
png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
1651
/* set up filtering buffer, if using this filter */
1652
if (png_ptr->do_filter & PNG_FILTER_SUB)
1654
png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1655
(png_ptr->rowbytes + 1));
1656
png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1659
/* We only need to keep the previous row if we are using one of these. */
1660
if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
1662
/* set up previous row buffer */
1663
png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
1664
png_memset(png_ptr->prev_row, 0, buf_size);
1666
if (png_ptr->do_filter & PNG_FILTER_UP)
1668
png_ptr->up_row = (png_bytep )png_malloc(png_ptr,
1669
(png_ptr->rowbytes + 1));
1670
png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1673
if (png_ptr->do_filter & PNG_FILTER_AVG)
1675
png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1676
(png_ptr->rowbytes + 1));
1677
png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1680
if (png_ptr->do_filter & PNG_FILTER_PAETH)
1682
png_ptr->paeth_row = (png_bytep )png_malloc(png_ptr,
1683
(png_ptr->rowbytes + 1));
1684
png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1688
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1689
/* if interlaced, we need to set up width and height of pass */
1690
if (png_ptr->interlaced)
1692
if (!(png_ptr->transformations & PNG_INTERLACE))
1694
png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
1695
png_pass_ystart[0]) / png_pass_yinc[0];
1696
png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
1697
png_pass_start[0]) / png_pass_inc[0];
1701
png_ptr->num_rows = png_ptr->height;
1702
png_ptr->usr_width = png_ptr->width;
1708
png_ptr->num_rows = png_ptr->height;
1709
png_ptr->usr_width = png_ptr->width;
1711
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1712
png_ptr->zstream.next_out = png_ptr->zbuf;
1715
/* Internal use only. Called when finished processing a row of data. */
1717
png_write_finish_row(png_structp png_ptr)
1719
#ifdef PNG_USE_LOCAL_ARRAYS
1720
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1722
/* start of interlace block */
1723
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1725
/* offset to next interlace block */
1726
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1728
/* start of interlace block in the y direction */
1729
int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1731
/* offset to next interlace block in the y direction */
1732
int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1737
png_debug(1, "in png_write_finish_row\n");
1739
png_ptr->row_number++;
1741
/* see if we are done */
1742
if (png_ptr->row_number < png_ptr->num_rows)
1745
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1746
/* if interlaced, go to next pass */
1747
if (png_ptr->interlaced)
1749
png_ptr->row_number = 0;
1750
if (png_ptr->transformations & PNG_INTERLACE)
1756
/* loop until we find a non-zero width or height pass */
1760
if (png_ptr->pass >= 7)
1762
png_ptr->usr_width = (png_ptr->width +
1763
png_pass_inc[png_ptr->pass] - 1 -
1764
png_pass_start[png_ptr->pass]) /
1765
png_pass_inc[png_ptr->pass];
1766
png_ptr->num_rows = (png_ptr->height +
1767
png_pass_yinc[png_ptr->pass] - 1 -
1768
png_pass_ystart[png_ptr->pass]) /
1769
png_pass_yinc[png_ptr->pass];
1770
if (png_ptr->transformations & PNG_INTERLACE)
1772
} while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
1776
/* reset the row above the image for the next pass */
1777
if (png_ptr->pass < 7)
1779
if (png_ptr->prev_row != NULL)
1780
png_memset(png_ptr->prev_row, 0,
1781
(png_size_t) (((png_uint_32)png_ptr->usr_channels *
1782
(png_uint_32)png_ptr->usr_bit_depth *
1783
png_ptr->width + 7) >> 3) + 1);
1789
/* if we get here, we've just written the last row, so we need
1790
to flush the compressor */
1793
/* tell the compressor we are done */
1794
ret = deflate(&png_ptr->zstream, Z_FINISH);
1795
/* check for an error */
1798
/* check to see if we need more room */
1799
if (!(png_ptr->zstream.avail_out))
1801
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
1802
png_ptr->zstream.next_out = png_ptr->zbuf;
1803
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1806
else if (ret != Z_STREAM_END)
1808
if (png_ptr->zstream.msg != NULL)
1809
png_error(png_ptr, png_ptr->zstream.msg);
1811
png_error(png_ptr, "zlib error");
1813
} while (ret != Z_STREAM_END);
1815
/* write any extra space */
1816
if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
1818
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
1819
png_ptr->zstream.avail_out);
1822
deflateReset(&png_ptr->zstream);
1825
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
1826
/* Pick out the correct pixels for the interlace pass.
1827
* The basic idea here is to go through the row with a source
1828
* pointer and a destination pointer (sp and dp), and copy the
1829
* correct pixels for the pass. As the row gets compacted,
1830
* sp will always be >= dp, so we should never overwrite anything.
1831
* See the default: case for the easiest code to understand.
1834
png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
1836
#ifdef PNG_USE_LOCAL_ARRAYS
1837
/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1839
/* start of interlace block */
1840
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1842
/* offset to next interlace block */
1843
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1846
png_debug(1, "in png_do_write_interlace\n");
1847
/* we don't have to do anything on the last pass (6) */
1848
#if defined(PNG_USELESS_TESTS_SUPPORTED)
1849
if (row != NULL && row_info != NULL && pass < 6)
1854
/* each pixel depth is handled separately */
1855
switch (row_info->pixel_depth)
1865
png_uint_32 row_width = row_info->width;
1870
for (i = png_pass_start[pass]; i < row_width;
1871
i += png_pass_inc[pass])
1873
sp = row + (png_size_t)(i >> 3);
1874
value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
1875
d |= (value << shift);
1880
*dp++ = (png_byte)d;
1899
png_uint_32 row_width = row_info->width;
1904
for (i = png_pass_start[pass]; i < row_width;
1905
i += png_pass_inc[pass])
1907
sp = row + (png_size_t)(i >> 2);
1908
value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
1909
d |= (value << shift);
1914
*dp++ = (png_byte)d;
1932
png_uint_32 row_width = row_info->width;
1937
for (i = png_pass_start[pass]; i < row_width;
1938
i += png_pass_inc[pass])
1940
sp = row + (png_size_t)(i >> 1);
1941
value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
1942
d |= (value << shift);
1947
*dp++ = (png_byte)d;
1962
png_uint_32 row_width = row_info->width;
1963
png_size_t pixel_bytes;
1965
/* start at the beginning */
1967
/* find out how many bytes each pixel takes up */
1968
pixel_bytes = (row_info->pixel_depth >> 3);
1969
/* loop through the row, only looking at the pixels that
1971
for (i = png_pass_start[pass]; i < row_width;
1972
i += png_pass_inc[pass])
1974
/* find out where the original pixel is */
1975
sp = row + (png_size_t)i * pixel_bytes;
1976
/* move the pixel */
1978
png_memcpy(dp, sp, pixel_bytes);
1985
/* set new row width */
1986
row_info->width = (row_info->width +
1987
png_pass_inc[pass] - 1 -
1988
png_pass_start[pass]) /
1990
row_info->rowbytes = ((row_info->width *
1991
row_info->pixel_depth + 7) >> 3);
1996
/* This filters the row, chooses which filter to use, if it has not already
1997
* been specified by the application, and then writes the row out with the
2000
#define PNG_MAXSUM (~((png_uint_32)0) >> 1)
2001
#define PNG_HISHIFT 10
2002
#define PNG_LOMASK ((png_uint_32)0xffffL)
2003
#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
2005
png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
2007
png_bytep prev_row, best_row, row_buf;
2008
png_uint_32 mins, bpp;
2009
png_byte filter_to_do = png_ptr->do_filter;
2010
png_uint_32 row_bytes = row_info->rowbytes;
2011
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2012
int num_p_filters = (int)png_ptr->num_prev_filters;
2015
png_debug(1, "in png_write_find_filter\n");
2016
/* find out how many bytes offset each pixel is */
2017
bpp = (row_info->pixel_depth + 7) / 8;
2019
prev_row = png_ptr->prev_row;
2020
best_row = row_buf = png_ptr->row_buf;
2023
/* The prediction method we use is to find which method provides the
2024
* smallest value when summing the absolute values of the distances
2025
* from zero, using anything >= 128 as negative numbers. This is known
2026
* as the "minimum sum of absolute differences" heuristic. Other
2027
* heuristics are the "weighted minimum sum of absolute differences"
2028
* (experimental and can in theory improve compression), and the "zlib
2029
* predictive" method (not implemented yet), which does test compressions
2030
* of lines using different filter methods, and then chooses the
2031
* (series of) filter(s) that give minimum compressed data size (VERY
2032
* computationally expensive).
2034
* GRR 980525: consider also
2035
* (1) minimum sum of absolute differences from running average (i.e.,
2036
* keep running sum of non-absolute differences & count of bytes)
2037
* [track dispersion, too? restart average if dispersion too large?]
2038
* (1b) minimum sum of absolute differences from sliding average, probably
2039
* with window size <= deflate window (usually 32K)
2040
* (2) minimum sum of squared differences from zero or running average
2041
* (i.e., ~ root-mean-square approach)
2045
/* We don't need to test the 'no filter' case if this is the only filter
2046
* that has been chosen, as it doesn't actually do anything to the data.
2048
if ((filter_to_do & PNG_FILTER_NONE) &&
2049
filter_to_do != PNG_FILTER_NONE)
2052
png_uint_32 sum = 0;
2056
for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
2059
sum += (v < 128) ? v : 256 - v;
2062
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2063
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2065
png_uint_32 sumhi, sumlo;
2067
sumlo = sum & PNG_LOMASK;
2068
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
2070
/* Reduce the sum if we match any of the previous rows */
2071
for (j = 0; j < num_p_filters; j++)
2073
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2075
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2077
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2082
/* Factor in the cost of this filter (this is here for completeness,
2083
* but it makes no sense to have a "cost" for the NONE filter, as
2084
* it has the minimum possible computational cost - none).
2086
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2088
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
2091
if (sumhi > PNG_HIMASK)
2094
sum = (sumhi << PNG_HISHIFT) + sumlo;
2101
if (filter_to_do == PNG_FILTER_SUB)
2102
/* it's the only filter so no testing is needed */
2104
png_bytep rp, lp, dp;
2106
for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2111
for (lp = row_buf + 1; i < row_bytes;
2112
i++, rp++, lp++, dp++)
2114
*dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2116
best_row = png_ptr->sub_row;
2119
else if (filter_to_do & PNG_FILTER_SUB)
2121
png_bytep rp, dp, lp;
2122
png_uint_32 sum = 0, lmins = mins;
2126
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2127
/* We temporarily increase the "minimum sum" by the factor we
2128
* would reduce the sum of this filter, so that we can do the
2129
* early exit comparison without scaling the sum each time.
2131
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2134
png_uint_32 lmhi, lmlo;
2135
lmlo = lmins & PNG_LOMASK;
2136
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2138
for (j = 0; j < num_p_filters; j++)
2140
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2142
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2144
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2149
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2151
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2154
if (lmhi > PNG_HIMASK)
2157
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2161
for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
2166
sum += (v < 128) ? v : 256 - v;
2168
for (lp = row_buf + 1; i < row_info->rowbytes;
2169
i++, rp++, lp++, dp++)
2171
v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
2173
sum += (v < 128) ? v : 256 - v;
2175
if (sum > lmins) /* We are already worse, don't continue. */
2179
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2180
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2183
png_uint_32 sumhi, sumlo;
2184
sumlo = sum & PNG_LOMASK;
2185
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2187
for (j = 0; j < num_p_filters; j++)
2189
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
2191
sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
2193
sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
2198
sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2200
sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
2203
if (sumhi > PNG_HIMASK)
2206
sum = (sumhi << PNG_HISHIFT) + sumlo;
2213
best_row = png_ptr->sub_row;
2218
if (filter_to_do == PNG_FILTER_UP)
2220
png_bytep rp, dp, pp;
2223
for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2224
pp = prev_row + 1; i < row_bytes;
2225
i++, rp++, pp++, dp++)
2227
*dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
2229
best_row = png_ptr->up_row;
2232
else if (filter_to_do & PNG_FILTER_UP)
2234
png_bytep rp, dp, pp;
2235
png_uint_32 sum = 0, lmins = mins;
2240
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2241
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2244
png_uint_32 lmhi, lmlo;
2245
lmlo = lmins & PNG_LOMASK;
2246
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2248
for (j = 0; j < num_p_filters; j++)
2250
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2252
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2254
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2259
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2261
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
2264
if (lmhi > PNG_HIMASK)
2267
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2271
for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
2272
pp = prev_row + 1; i < row_bytes; i++)
2274
v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2276
sum += (v < 128) ? v : 256 - v;
2278
if (sum > lmins) /* We are already worse, don't continue. */
2282
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2283
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2286
png_uint_32 sumhi, sumlo;
2287
sumlo = sum & PNG_LOMASK;
2288
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2290
for (j = 0; j < num_p_filters; j++)
2292
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
2294
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2296
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2301
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2303
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
2306
if (sumhi > PNG_HIMASK)
2309
sum = (sumhi << PNG_HISHIFT) + sumlo;
2316
best_row = png_ptr->up_row;
2321
if (filter_to_do == PNG_FILTER_AVG)
2323
png_bytep rp, dp, pp, lp;
2325
for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2326
pp = prev_row + 1; i < bpp; i++)
2328
*dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2330
for (lp = row_buf + 1; i < row_bytes; i++)
2332
*dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
2335
best_row = png_ptr->avg_row;
2338
else if (filter_to_do & PNG_FILTER_AVG)
2340
png_bytep rp, dp, pp, lp;
2341
png_uint_32 sum = 0, lmins = mins;
2345
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2346
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2349
png_uint_32 lmhi, lmlo;
2350
lmlo = lmins & PNG_LOMASK;
2351
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2353
for (j = 0; j < num_p_filters; j++)
2355
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
2357
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2359
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2364
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2366
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
2369
if (lmhi > PNG_HIMASK)
2372
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2376
for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
2377
pp = prev_row + 1; i < bpp; i++)
2379
v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
2381
sum += (v < 128) ? v : 256 - v;
2383
for (lp = row_buf + 1; i < row_bytes; i++)
2386
(png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
2388
sum += (v < 128) ? v : 256 - v;
2390
if (sum > lmins) /* We are already worse, don't continue. */
2394
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2395
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2398
png_uint_32 sumhi, sumlo;
2399
sumlo = sum & PNG_LOMASK;
2400
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2402
for (j = 0; j < num_p_filters; j++)
2404
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
2406
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2408
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2413
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2415
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
2418
if (sumhi > PNG_HIMASK)
2421
sum = (sumhi << PNG_HISHIFT) + sumlo;
2428
best_row = png_ptr->avg_row;
2433
if (filter_to_do == PNG_FILTER_PAETH)
2435
png_bytep rp, dp, pp, cp, lp;
2437
for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2438
pp = prev_row + 1; i < bpp; i++)
2440
*dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2443
for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2445
int a, b, c, pa, pb, pc, p;
2459
pa = p < 0 ? -p : p;
2460
pb = pc < 0 ? -pc : pc;
2461
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2464
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2466
*dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2468
best_row = png_ptr->paeth_row;
2471
else if (filter_to_do & PNG_FILTER_PAETH)
2473
png_bytep rp, dp, pp, cp, lp;
2474
png_uint_32 sum = 0, lmins = mins;
2478
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2479
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2482
png_uint_32 lmhi, lmlo;
2483
lmlo = lmins & PNG_LOMASK;
2484
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
2486
for (j = 0; j < num_p_filters; j++)
2488
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2490
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
2492
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
2497
lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2499
lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2502
if (lmhi > PNG_HIMASK)
2505
lmins = (lmhi << PNG_HISHIFT) + lmlo;
2509
for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
2510
pp = prev_row + 1; i < bpp; i++)
2512
v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
2514
sum += (v < 128) ? v : 256 - v;
2517
for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
2519
int a, b, c, pa, pb, pc, p;
2525
#ifndef PNG_SLOW_PAETH
2533
pa = p < 0 ? -p : p;
2534
pb = pc < 0 ? -pc : pc;
2535
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
2537
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
2538
#else /* PNG_SLOW_PAETH */
2543
if (pa <= pb && pa <= pc)
2549
#endif /* PNG_SLOW_PAETH */
2551
v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
2553
sum += (v < 128) ? v : 256 - v;
2555
if (sum > lmins) /* We are already worse, don't continue. */
2559
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2560
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
2563
png_uint_32 sumhi, sumlo;
2564
sumlo = sum & PNG_LOMASK;
2565
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
2567
for (j = 0; j < num_p_filters; j++)
2569
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
2571
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
2573
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
2578
sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2580
sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
2583
if (sumhi > PNG_HIMASK)
2586
sum = (sumhi << PNG_HISHIFT) + sumlo;
2592
best_row = png_ptr->paeth_row;
2596
/* Do the actual writing of the filtered row data from the chosen filter. */
2598
png_write_filtered_row(png_ptr, best_row);
2600
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
2601
/* Save the type of filter we picked this time for future calculations */
2602
if (png_ptr->num_prev_filters > 0)
2605
for (j = 1; j < num_p_filters; j++)
2607
png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
2609
png_ptr->prev_filters[j] = best_row[0];
2615
/* Do the actual writing of a previously filtered row. */
2617
png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
2619
png_debug(1, "in png_write_filtered_row\n");
2620
png_debug1(2, "filter = %d\n", filtered_row[0]);
2621
/* set up the zlib input buffer */
2623
png_ptr->zstream.next_in = filtered_row;
2624
png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
2625
/* repeat until we have compressed all the data */
2628
int ret; /* return of zlib */
2630
/* compress the data */
2631
ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
2632
/* check for compression errors */
2635
if (png_ptr->zstream.msg != NULL)
2636
png_error(png_ptr, png_ptr->zstream.msg);
2638
png_error(png_ptr, "zlib error");
2641
/* see if it is time to write another IDAT */
2642
if (!(png_ptr->zstream.avail_out))
2644
/* write the IDAT and reset the zlib output buffer */
2645
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
2646
png_ptr->zstream.next_out = png_ptr->zbuf;
2647
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
2649
/* repeat until all data has been compressed */
2650
} while (png_ptr->zstream.avail_in);
2652
/* swap the current and previous rows */
2653
if (png_ptr->prev_row != NULL)
2657
tptr = png_ptr->prev_row;
2658
png_ptr->prev_row = png_ptr->row_buf;
2659
png_ptr->row_buf = tptr;
2662
/* finish row - updates counters and flushes zlib if last row */
2663
png_write_finish_row(png_ptr);
2665
#if defined(PNG_WRITE_FLUSH_SUPPORTED)
2666
png_ptr->flush_rows++;
2668
if (png_ptr->flush_dist > 0 &&
2669
png_ptr->flush_rows >= png_ptr->flush_dist)
2671
png_write_flush(png_ptr);
2675
#endif /* PNG_WRITE_SUPPORTED */