/* pngwutil.c - utilities to write a PNG file
*
- * Last changed in libpng 1.2.43 [February 25, 2010]
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
+ * Copyright (c) 1996-1997 Andreas Dilger
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*/
-#define PNG_INTERNAL
-#define PNG_NO_PEDANTIC_WARNINGS
-#include "png.h"
+#include "pngpriv.h"
+
#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
/* Place a 32-bit number into a buffer in PNG byte order. We work
* with unsigned numbers for convenience, although one supported
* ancillary chunk uses signed (two's complement) numbers.
void PNGAPI
png_save_uint_32(png_bytep buf, png_uint_32 i)
{
- buf[0] = (png_byte)((i >> 24) & 0xff);
- buf[1] = (png_byte)((i >> 16) & 0xff);
- buf[2] = (png_byte)((i >> 8) & 0xff);
- buf[3] = (png_byte)(i & 0xff);
-}
-
-/* The png_save_int_32 function assumes integers are stored in two's
- * complement format. If this isn't the case, then this routine needs to
- * be modified to write data in two's complement format.
- */
-void PNGAPI
-png_save_int_32(png_bytep buf, png_int_32 i)
-{
- buf[0] = (png_byte)((i >> 24) & 0xff);
- buf[1] = (png_byte)((i >> 16) & 0xff);
- buf[2] = (png_byte)((i >> 8) & 0xff);
- buf[3] = (png_byte)(i & 0xff);
+ buf[0] = (png_byte)((i >> 24) & 0xffU);
+ buf[1] = (png_byte)((i >> 16) & 0xffU);
+ buf[2] = (png_byte)((i >> 8) & 0xffU);
+ buf[3] = (png_byte)( i & 0xffU);
}
/* Place a 16-bit number into a buffer in PNG byte order.
void PNGAPI
png_save_uint_16(png_bytep buf, unsigned int i)
{
- buf[0] = (png_byte)((i >> 8) & 0xff);
- buf[1] = (png_byte)(i & 0xff);
+ buf[0] = (png_byte)((i >> 8) & 0xffU);
+ buf[1] = (png_byte)( i & 0xffU);
}
+#endif
/* Simple function to write the signature. If we have already written
* the magic bytes of the signature, or more likely, the PNG stream is
* we should call png_set_sig_bytes() to tell libpng how many of the
* bytes have already been written.
*/
-void /* PRIVATE */
-png_write_sig(png_structp png_ptr)
+void PNGAPI
+png_write_sig(png_structrp png_ptr)
{
png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the signature is being written */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
+#endif
+
/* Write the rest of the 8 byte signature */
png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
- (png_size_t)(8 - png_ptr->sig_bytes));
+ (size_t)(8 - png_ptr->sig_bytes));
+
if (png_ptr->sig_bytes < 3)
png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
}
-/* Write a PNG chunk all at once. The type is an array of ASCII characters
- * representing the chunk name. The array must be at least 4 bytes in
- * length, and does not need to be null terminated. To be safe, pass the
- * pre-defined chunk names here, and if you need a new one, define it
- * where the others are defined. The length is the length of the data.
- * All the data must be present. If that is not possible, use the
- * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
- * functions instead.
- */
-void PNGAPI
-png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
- png_bytep data, png_size_t length)
-{
- if (png_ptr == NULL)
- return;
- png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
- png_write_chunk_data(png_ptr, data, (png_size_t)length);
- png_write_chunk_end(png_ptr);
-}
-
/* Write the start of a PNG chunk. The type is the chunk type.
* The total_length is the sum of the lengths of all the data you will be
* passing in png_write_chunk_data().
*/
-void PNGAPI
-png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
- png_uint_32 length)
+static void
+png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name,
+ png_uint_32 length)
{
png_byte buf[8];
- png_debug2(0, "Writing %s chunk, length = %lu", chunk_name,
- (unsigned long)length);
+#if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
+ PNG_CSTRING_FROM_CHUNK(buf, chunk_name);
+ png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);
+#endif
if (png_ptr == NULL)
return;
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the chunk header is being written.
+ * PNG_IO_CHUNK_HDR requires a single I/O call.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
+#endif
/* Write the length and the chunk name */
png_save_uint_32(buf, length);
- png_memcpy(buf + 4, chunk_name, 4);
- png_write_data(png_ptr, buf, (png_size_t)8);
+ png_save_uint_32(buf + 4, chunk_name);
+ png_write_data(png_ptr, buf, 8);
+
/* Put the chunk name into png_ptr->chunk_name */
- png_memcpy(png_ptr->chunk_name, chunk_name, 4);
+ png_ptr->chunk_name = chunk_name;
+
/* Reset the crc and run it over the chunk name */
png_reset_crc(png_ptr);
- png_calculate_crc(png_ptr, chunk_name, (png_size_t)4);
+
+ png_calculate_crc(png_ptr, buf + 4, 4);
+
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that chunk data will (possibly) be written.
+ * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
+#endif
+}
+
+void PNGAPI
+png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string,
+ png_uint_32 length)
+{
+ png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);
}
-/* Write the data of a PNG chunk started with png_write_chunk_start().
+/* Write the data of a PNG chunk started with png_write_chunk_header().
* Note that multiple calls to this function are allowed, and that the
* sum of the lengths from these calls *must* add up to the total_length
- * given to png_write_chunk_start().
+ * given to png_write_chunk_header().
*/
void PNGAPI
-png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
+png_write_chunk_data(png_structrp png_ptr, png_const_bytep data, size_t length)
{
/* Write the data, and run the CRC over it */
if (png_ptr == NULL)
return;
+
if (data != NULL && length > 0)
{
png_write_data(png_ptr, data, length);
+
/* Update the CRC after writing the data,
- * in case that the user I/O routine alters it.
+ * in case the user I/O routine alters it.
*/
png_calculate_crc(png_ptr, data, length);
}
}
-/* Finish a chunk started with png_write_chunk_start(). */
+/* Finish a chunk started with png_write_chunk_header(). */
void PNGAPI
-png_write_chunk_end(png_structp png_ptr)
+png_write_chunk_end(png_structrp png_ptr)
{
png_byte buf[4];
if (png_ptr == NULL) return;
+#ifdef PNG_IO_STATE_SUPPORTED
+ /* Inform the I/O callback that the chunk CRC is being written.
+ * PNG_IO_CHUNK_CRC requires a single I/O function call.
+ */
+ png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
+#endif
+
/* Write the crc in a single operation */
png_save_uint_32(buf, png_ptr->crc);
- png_write_data(png_ptr, buf, (png_size_t)4);
+ png_write_data(png_ptr, buf, 4);
}
-#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
-/* This pair of functions encapsulates the operation of (a) compressing a
- * text string, and (b) issuing it later as a series of chunk data writes.
- * The compression_state structure is shared context for these functions
- * set up by the caller in order to make the whole mess thread-safe.
+/* Write a PNG chunk all at once. The type is an array of ASCII characters
+ * representing the chunk name. The array must be at least 4 bytes in
+ * length, and does not need to be null terminated. To be safe, pass the
+ * pre-defined chunk names here, and if you need a new one, define it
+ * where the others are defined. The length is the length of the data.
+ * All the data must be present. If that is not possible, use the
+ * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
+ * functions instead.
*/
-
-typedef struct
+static void
+png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name,
+ png_const_bytep data, size_t length)
{
- char *input; /* The uncompressed input data */
- int input_len; /* Its length */
- int num_output_ptr; /* Number of output pointers used */
- int max_output_ptr; /* Size of output_ptr */
- png_charpp output_ptr; /* Array of pointers to output */
-} compression_state;
+ if (png_ptr == NULL)
+ return;
+
+ /* On 64-bit architectures 'length' may not fit in a png_uint_32. */
+ if (length > PNG_UINT_31_MAX)
+ png_error(png_ptr, "length exceeds PNG maximum");
-/* Compress given text into storage in the png_ptr structure */
-static int /* PRIVATE */
-png_text_compress(png_structp png_ptr,
- png_charp text, png_size_t text_len, int compression,
- compression_state *comp)
+ png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
+ png_write_chunk_data(png_ptr, data, length);
+ png_write_chunk_end(png_ptr);
+}
+
+/* This is the API that calls the internal function above. */
+void PNGAPI
+png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string,
+ png_const_bytep data, size_t length)
{
- int ret;
+ png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
+ length);
+}
- comp->num_output_ptr = 0;
- comp->max_output_ptr = 0;
- comp->output_ptr = NULL;
- comp->input = NULL;
- comp->input_len = 0;
+/* This is used below to find the size of an image to pass to png_deflate_claim,
+ * so it only needs to be accurate if the size is less than 16384 bytes (the
+ * point at which a lower LZ window size can be used.)
+ */
+static png_alloc_size_t
+png_image_size(png_structrp png_ptr)
+{
+ /* Only return sizes up to the maximum of a png_uint_32; do this by limiting
+ * the width and height used to 15 bits.
+ */
+ png_uint_32 h = png_ptr->height;
- /* We may just want to pass the text right through */
- if (compression == PNG_TEXT_COMPRESSION_NONE)
+ if (png_ptr->rowbytes < 32768 && h < 32768)
{
- comp->input = text;
- comp->input_len = text_len;
- return((int)text_len);
+ if (png_ptr->interlaced != 0)
+ {
+ /* Interlacing makes the image larger because of the replication of
+ * both the filter byte and the padding to a byte boundary.
+ */
+ png_uint_32 w = png_ptr->width;
+ unsigned int pd = png_ptr->pixel_depth;
+ png_alloc_size_t cb_base;
+ int pass;
+
+ for (cb_base=0, pass=0; pass<=6; ++pass)
+ {
+ png_uint_32 pw = PNG_PASS_COLS(w, pass);
+
+ if (pw > 0)
+ cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
+ }
+
+ return cb_base;
+ }
+
+ else
+ return (png_ptr->rowbytes+1) * h;
}
- if (compression >= PNG_TEXT_COMPRESSION_LAST)
+ else
+ return 0xffffffffU;
+}
+
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ /* This is the code to hack the first two bytes of the deflate stream (the
+ * deflate header) to correct the windowBits value to match the actual data
+ * size. Note that the second argument is the *uncompressed* size but the
+ * first argument is the *compressed* data (and it must be deflate
+ * compressed.)
+ */
+static void
+optimize_cmf(png_bytep data, png_alloc_size_t data_size)
+{
+ /* Optimize the CMF field in the zlib stream. The resultant zlib stream is
+ * still compliant to the stream specification.
+ */
+ if (data_size <= 16384) /* else windowBits must be 15 */
{
-#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
- char msg[50];
- png_snprintf(msg, 50, "Unknown compression type %d", compression);
- png_warning(png_ptr, msg);
-#else
- png_warning(png_ptr, "Unknown compression type");
-#endif
+ unsigned int z_cmf = data[0]; /* zlib compression method and flags */
+
+ if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+ {
+ unsigned int z_cinfo;
+ unsigned int half_z_window_size;
+
+ z_cinfo = z_cmf >> 4;
+ half_z_window_size = 1U << (z_cinfo + 7);
+
+ if (data_size <= half_z_window_size) /* else no change */
+ {
+ unsigned int tmp;
+
+ do
+ {
+ half_z_window_size >>= 1;
+ --z_cinfo;
+ }
+ while (z_cinfo > 0 && data_size <= half_z_window_size);
+
+ z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
+
+ data[0] = (png_byte)z_cmf;
+ tmp = data[1] & 0xe0;
+ tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
+ data[1] = (png_byte)tmp;
+ }
+ }
}
+}
+#endif /* WRITE_OPTIMIZE_CMF */
- /* We can't write the chunk until we find out how much data we have,
- * which means we need to run the compressor first and save the
- * output. This shouldn't be a problem, as the vast majority of
- * comments should be reasonable, but we will set up an array of
- * malloc'd pointers to be sure.
- *
- * If we knew the application was well behaved, we could simplify this
- * greatly by assuming we can always malloc an output buffer large
- * enough to hold the compressed text ((1001 * text_len / 1000) + 12)
- * and malloc this directly. The only time this would be a bad idea is
- * if we can't malloc more than 64K and we have 64K of random input
- * data, or if the input string is incredibly large (although this
- * wouldn't cause a failure, just a slowdown due to swapping).
- */
+/* Initialize the compressor for the appropriate type of compression. */
+static int
+png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
+ png_alloc_size_t data_size)
+{
+ if (png_ptr->zowner != 0)
+ {
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
+ char msg[64];
+
+ PNG_STRING_FROM_CHUNK(msg, owner);
+ msg[4] = ':';
+ msg[5] = ' ';
+ PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner);
+ /* So the message that results is "<chunk> using zstream"; this is an
+ * internal error, but is very useful for debugging. i18n requirements
+ * are minimal.
+ */
+ (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
+#endif
+#if PNG_RELEASE_BUILD
+ png_warning(png_ptr, msg);
+
+ /* Attempt sane error recovery */
+ if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */
+ {
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT");
+ return Z_STREAM_ERROR;
+ }
- /* Set up the compression buffers */
- png_ptr->zstream.avail_in = (uInt)text_len;
- png_ptr->zstream.next_in = (Bytef *)text;
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;
+ png_ptr->zowner = 0;
+#else
+ png_error(png_ptr, msg);
+#endif
+ }
- /* This is the same compression loop as in png_write_row() */
- do
{
- /* Compress the data */
- ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
- if (ret != Z_OK)
+ int level = png_ptr->zlib_level;
+ int method = png_ptr->zlib_method;
+ int windowBits = png_ptr->zlib_window_bits;
+ int memLevel = png_ptr->zlib_mem_level;
+ int strategy; /* set below */
+ int ret; /* zlib return code */
+
+ if (owner == png_IDAT)
{
- /* Error */
- if (png_ptr->zstream.msg != NULL)
- png_error(png_ptr, png_ptr->zstream.msg);
+ if ((png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) != 0)
+ strategy = png_ptr->zlib_strategy;
+
+ else if (png_ptr->do_filter != PNG_FILTER_NONE)
+ strategy = PNG_Z_DEFAULT_STRATEGY;
+
else
- png_error(png_ptr, "zlib error");
+ strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY;
}
- /* Check to see if we need more room */
- if (!(png_ptr->zstream.avail_out))
+
+ else
{
- /* Make sure the output array has room */
- if (comp->num_output_ptr >= comp->max_output_ptr)
- {
- int old_max;
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+ level = png_ptr->zlib_text_level;
+ method = png_ptr->zlib_text_method;
+ windowBits = png_ptr->zlib_text_window_bits;
+ memLevel = png_ptr->zlib_text_mem_level;
+ strategy = png_ptr->zlib_text_strategy;
+#else
+ /* If customization is not supported the values all come from the
+ * IDAT values except for the strategy, which is fixed to the
+ * default. (This is the pre-1.6.0 behavior too, although it was
+ * implemented in a very different way.)
+ */
+ strategy = Z_DEFAULT_STRATEGY;
+#endif
+ }
- old_max = comp->max_output_ptr;
- comp->max_output_ptr = comp->num_output_ptr + 4;
- if (comp->output_ptr != NULL)
- {
- png_charpp old_ptr;
-
- old_ptr = comp->output_ptr;
- comp->output_ptr = (png_charpp)png_malloc(png_ptr,
- (png_uint_32)
- (comp->max_output_ptr * png_sizeof(png_charpp)));
- png_memcpy(comp->output_ptr, old_ptr, old_max
- * png_sizeof(png_charp));
- png_free(png_ptr, old_ptr);
- }
- else
- comp->output_ptr = (png_charpp)png_malloc(png_ptr,
- (png_uint_32)
- (comp->max_output_ptr * png_sizeof(png_charp)));
+ /* Adjust 'windowBits' down if larger than 'data_size'; to stop this
+ * happening just pass 32768 as the data_size parameter. Notice that zlib
+ * requires an extra 262 bytes in the window in addition to the data to be
+ * able to see the whole of the data, so if data_size+262 takes us to the
+ * next windowBits size we need to fix up the value later. (Because even
+ * though deflate needs the extra window, inflate does not!)
+ */
+ if (data_size <= 16384)
+ {
+ /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to
+ * work round a Microsoft Visual C misbehavior which, contrary to C-90,
+ * widens the result of the following shift to 64-bits if (and,
+ * apparently, only if) it is used in a test.
+ */
+ unsigned int half_window_size = 1U << (windowBits-1);
+
+ while (data_size + 262 <= half_window_size)
+ {
+ half_window_size >>= 1;
+ --windowBits;
}
+ }
+
+ /* Check against the previous initialized values, if any. */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0 &&
+ (png_ptr->zlib_set_level != level ||
+ png_ptr->zlib_set_method != method ||
+ png_ptr->zlib_set_window_bits != windowBits ||
+ png_ptr->zlib_set_mem_level != memLevel ||
+ png_ptr->zlib_set_strategy != strategy))
+ {
+ if (deflateEnd(&png_ptr->zstream) != Z_OK)
+ png_warning(png_ptr, "deflateEnd failed (ignored)");
- /* Save the data */
- comp->output_ptr[comp->num_output_ptr] =
- (png_charp)png_malloc(png_ptr,
- (png_uint_32)png_ptr->zbuf_size);
- png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
- png_ptr->zbuf_size);
- comp->num_output_ptr++;
-
- /* and reset the buffer */
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED;
}
- /* Continue until we don't have any more to compress */
- } while (png_ptr->zstream.avail_in);
- /* Finish the compression */
- do
- {
- /* Tell zlib we are finished */
- ret = deflate(&png_ptr->zstream, Z_FINISH);
+ /* For safety clear out the input and output pointers (currently zlib
+ * doesn't use them on Init, but it might in the future).
+ */
+ png_ptr->zstream.next_in = NULL;
+ png_ptr->zstream.avail_in = 0;
+ png_ptr->zstream.next_out = NULL;
+ png_ptr->zstream.avail_out = 0;
+
+ /* Now initialize if required, setting the new parameters, otherwise just
+ * do a simple reset to the previous parameters.
+ */
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
+ ret = deflateReset(&png_ptr->zstream);
+ else
+ {
+ ret = deflateInit2(&png_ptr->zstream, level, method, windowBits,
+ memLevel, strategy);
+
+ if (ret == Z_OK)
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
+ }
+
+ /* The return code is from either deflateReset or deflateInit2; they have
+ * pretty much the same set of error codes.
+ */
if (ret == Z_OK)
+ png_ptr->zowner = owner;
+
+ else
+ png_zstream_error(png_ptr, ret);
+
+ return ret;
+ }
+}
+
+/* Clean up (or trim) a linked list of compression buffers. */
+void /* PRIVATE */
+png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
+{
+ png_compression_bufferp list = *listp;
+
+ if (list != NULL)
+ {
+ *listp = NULL;
+
+ do
+ {
+ png_compression_bufferp next = list->next;
+
+ png_free(png_ptr, list);
+ list = next;
+ }
+ while (list != NULL);
+ }
+}
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+/* This pair of functions encapsulates the operation of (a) compressing a
+ * text string, and (b) issuing it later as a series of chunk data writes.
+ * The compression_state structure is shared context for these functions
+ * set up by the caller to allow access to the relevant local variables.
+ *
+ * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size
+ * temporary buffers. From 1.6.0 it is retained in png_struct so that it will
+ * be correctly freed in the event of a write error (previous implementations
+ * just leaked memory.)
+ */
+typedef struct
+{
+ png_const_bytep input; /* The uncompressed input data */
+ png_alloc_size_t input_len; /* Its length */
+ png_uint_32 output_len; /* Final compressed length */
+ png_byte output[1024]; /* First block of output */
+} compression_state;
+
+static void
+png_text_compress_init(compression_state *comp, png_const_bytep input,
+ png_alloc_size_t input_len)
+{
+ comp->input = input;
+ comp->input_len = input_len;
+ comp->output_len = 0;
+}
+
+/* Compress the data in the compression state input */
+static int
+png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
+ compression_state *comp, png_uint_32 prefix_len)
+{
+ int ret;
+
+ /* To find the length of the output it is necessary to first compress the
+ * input. The result is buffered rather than using the two-pass algorithm
+ * that is used on the inflate side; deflate is assumed to be slower and a
+ * PNG writer is assumed to have more memory available than a PNG reader.
+ *
+ * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an
+ * upper limit on the output size, but it is always bigger than the input
+ * size so it is likely to be more efficient to use this linked-list
+ * approach.
+ */
+ ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len);
+
+ if (ret != Z_OK)
+ return ret;
+
+ /* Set up the compression buffers, we need a loop here to avoid overflowing a
+ * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited
+ * by the output buffer size, so there is no need to check that. Since this
+ * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits
+ * in size.
+ */
+ {
+ png_compression_bufferp *end = &png_ptr->zbuffer_list;
+ png_alloc_size_t input_len = comp->input_len; /* may be zero! */
+ png_uint_32 output_len;
+
+ /* zlib updates these for us: */
+ png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input);
+ png_ptr->zstream.avail_in = 0; /* Set below */
+ png_ptr->zstream.next_out = comp->output;
+ png_ptr->zstream.avail_out = (sizeof comp->output);
+
+ output_len = png_ptr->zstream.avail_out;
+
+ do
{
- /* Check to see if we need more room */
- if (!(png_ptr->zstream.avail_out))
+ uInt avail_in = ZLIB_IO_MAX;
+
+ if (avail_in > input_len)
+ avail_in = (uInt)input_len;
+
+ input_len -= avail_in;
+
+ png_ptr->zstream.avail_in = avail_in;
+
+ if (png_ptr->zstream.avail_out == 0)
{
- /* Check to make sure our output array has room */
- if (comp->num_output_ptr >= comp->max_output_ptr)
+ png_compression_buffer *next;
+
+ /* Chunk data is limited to 2^31 bytes in length, so the prefix
+ * length must be counted here.
+ */
+ if (output_len + prefix_len > PNG_UINT_31_MAX)
+ {
+ ret = Z_MEM_ERROR;
+ break;
+ }
+
+ /* Need a new (malloc'ed) buffer, but there may be one present
+ * already.
+ */
+ next = *end;
+ if (next == NULL)
{
- int old_max;
+ next = png_voidcast(png_compression_bufferp, png_malloc_base
+ (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
- old_max = comp->max_output_ptr;
- comp->max_output_ptr = comp->num_output_ptr + 4;
- if (comp->output_ptr != NULL)
+ if (next == NULL)
{
- png_charpp old_ptr;
-
- old_ptr = comp->output_ptr;
- /* This could be optimized to realloc() */
- comp->output_ptr = (png_charpp)png_malloc(png_ptr,
- (png_uint_32)(comp->max_output_ptr *
- png_sizeof(png_charp)));
- png_memcpy(comp->output_ptr, old_ptr,
- old_max * png_sizeof(png_charp));
- png_free(png_ptr, old_ptr);
+ ret = Z_MEM_ERROR;
+ break;
}
- else
- comp->output_ptr = (png_charpp)png_malloc(png_ptr,
- (png_uint_32)(comp->max_output_ptr *
- png_sizeof(png_charp)));
+
+ /* Link in this buffer (so that it will be freed later) */
+ next->next = NULL;
+ *end = next;
}
- /* Save the data */
- comp->output_ptr[comp->num_output_ptr] =
- (png_charp)png_malloc(png_ptr,
- (png_uint_32)png_ptr->zbuf_size);
- png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
- png_ptr->zbuf_size);
- comp->num_output_ptr++;
-
- /* and reset the buffer pointers */
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.next_out = next->output;
+ png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
+ output_len += png_ptr->zstream.avail_out;
+
+ /* Move 'end' to the next buffer pointer. */
+ end = &next->next;
}
+
+ /* Compress the data */
+ ret = deflate(&png_ptr->zstream,
+ input_len > 0 ? Z_NO_FLUSH : Z_FINISH);
+
+ /* Claw back input data that was not consumed (because avail_in is
+ * reset above every time round the loop).
+ */
+ input_len += png_ptr->zstream.avail_in;
+ png_ptr->zstream.avail_in = 0; /* safety */
}
- else if (ret != Z_STREAM_END)
+ while (ret == Z_OK);
+
+ /* There may be some space left in the last output buffer. This needs to
+ * be subtracted from output_len.
+ */
+ output_len -= png_ptr->zstream.avail_out;
+ png_ptr->zstream.avail_out = 0; /* safety */
+ comp->output_len = output_len;
+
+ /* Now double check the output length, put in a custom message if it is
+ * too long. Otherwise ensure the z_stream::msg pointer is set to
+ * something.
+ */
+ if (output_len + prefix_len >= PNG_UINT_31_MAX)
{
- /* We got an error */
- if (png_ptr->zstream.msg != NULL)
- png_error(png_ptr, png_ptr->zstream.msg);
- else
- png_error(png_ptr, "zlib error");
+ png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long");
+ ret = Z_MEM_ERROR;
}
- } while (ret != Z_STREAM_END);
- /* Text length is number of buffers plus last buffer */
- text_len = png_ptr->zbuf_size * comp->num_output_ptr;
- if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
- text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
+ else
+ png_zstream_error(png_ptr, ret);
+
+ /* Reset zlib for another zTXt/iTXt or image data */
+ png_ptr->zowner = 0;
+
+ /* The only success case is Z_STREAM_END, input_len must be 0; if not this
+ * is an internal error.
+ */
+ if (ret == Z_STREAM_END && input_len == 0)
+ {
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ /* Fix up the deflate header, if required */
+ optimize_cmf(comp->output, comp->input_len);
+#endif
+ /* But Z_OK is returned, not Z_STREAM_END; this allows the claim
+ * function above to return Z_STREAM_END on an error (though it never
+ * does in the current versions of zlib.)
+ */
+ return Z_OK;
+ }
- return((int)text_len);
+ else
+ return ret;
+ }
}
/* Ship the compressed text out via chunk writes */
-static void /* PRIVATE */
-png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
+static void
+png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
{
- int i;
+ png_uint_32 output_len = comp->output_len;
+ png_const_bytep output = comp->output;
+ png_uint_32 avail = (sizeof comp->output);
+ png_compression_buffer *next = png_ptr->zbuffer_list;
- /* Handle the no-compression case */
- if (comp->input)
+ for (;;)
{
- png_write_chunk_data(png_ptr, (png_bytep)comp->input,
- (png_size_t)comp->input_len);
- return;
- }
+ if (avail > output_len)
+ avail = output_len;
- /* Write saved output buffers, if any */
- for (i = 0; i < comp->num_output_ptr; i++)
- {
- png_write_chunk_data(png_ptr, (png_bytep)comp->output_ptr[i],
- (png_size_t)png_ptr->zbuf_size);
- png_free(png_ptr, comp->output_ptr[i]);
- comp->output_ptr[i]=NULL;
+ png_write_chunk_data(png_ptr, output, avail);
+
+ output_len -= avail;
+
+ if (output_len == 0 || next == NULL)
+ break;
+
+ avail = png_ptr->zbuffer_size;
+ output = next->output;
+ next = next->next;
}
- if (comp->max_output_ptr != 0)
- png_free(png_ptr, comp->output_ptr);
- comp->output_ptr=NULL;
- /* Write anything left in zbuf */
- if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
- png_write_chunk_data(png_ptr, png_ptr->zbuf,
- (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
- /* Reset zlib for another zTXt/iTXt or image data */
- deflateReset(&png_ptr->zstream);
- png_ptr->zstream.data_type = Z_BINARY;
+ /* This is an internal error; 'next' must have been NULL! */
+ if (output_len > 0)
+ png_error(png_ptr, "error writing ancillary chunked compressed data");
}
-#endif
+#endif /* WRITE_COMPRESSED_TEXT */
/* Write the IHDR chunk, and update the png_struct with the necessary
* information. Note that the rest of this code depends upon this
* information being correct.
*/
void /* PRIVATE */
-png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
- int bit_depth, int color_type, int compression_type, int filter_type,
- int interlace_type)
+png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height,
+ int bit_depth, int color_type, int compression_type, int filter_type,
+ int interlace_type)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_IHDR;
-#endif
- int ret;
-
png_byte buf[13]; /* Buffer to store the IHDR info */
+ int is_invalid_depth;
png_debug(1, "in png_write_IHDR");
case 2:
case 4:
case 8:
- case 16: png_ptr->channels = 1; break;
- default: png_error(png_ptr,
- "Invalid bit depth for grayscale image");
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ case 16:
+#endif
+ png_ptr->channels = 1; break;
+
+ default:
+ png_error(png_ptr,
+ "Invalid bit depth for grayscale image");
}
break;
+
case PNG_COLOR_TYPE_RGB:
- if (bit_depth != 8 && bit_depth != 16)
+ is_invalid_depth = (bit_depth != 8);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ is_invalid_depth = (is_invalid_depth && bit_depth != 16);
+#endif
+ if (is_invalid_depth)
png_error(png_ptr, "Invalid bit depth for RGB image");
+
png_ptr->channels = 3;
break;
+
case PNG_COLOR_TYPE_PALETTE:
switch (bit_depth)
{
case 1:
case 2:
case 4:
- case 8: png_ptr->channels = 1; break;
- default: png_error(png_ptr, "Invalid bit depth for paletted image");
+ case 8:
+ png_ptr->channels = 1;
+ break;
+
+ default:
+ png_error(png_ptr, "Invalid bit depth for paletted image");
}
break;
+
case PNG_COLOR_TYPE_GRAY_ALPHA:
- if (bit_depth != 8 && bit_depth != 16)
+ is_invalid_depth = (bit_depth != 8);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ is_invalid_depth = (is_invalid_depth && bit_depth != 16);
+#endif
+ if (is_invalid_depth)
png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
+
png_ptr->channels = 2;
break;
+
case PNG_COLOR_TYPE_RGB_ALPHA:
- if (bit_depth != 8 && bit_depth != 16)
+ is_invalid_depth = (bit_depth != 8);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ is_invalid_depth = (is_invalid_depth && bit_depth != 16);
+#endif
+ if (is_invalid_depth)
png_error(png_ptr, "Invalid bit depth for RGBA image");
+
png_ptr->channels = 4;
break;
+
default:
png_error(png_ptr, "Invalid image color type specified");
}
*/
if (
#ifdef PNG_MNG_FEATURES_SUPPORTED
- !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
- ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
- (color_type == PNG_COLOR_TYPE_RGB ||
- color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
- (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
+ !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+ ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+ (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
+ (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
#endif
- filter_type != PNG_FILTER_TYPE_BASE)
+ filter_type != PNG_FILTER_TYPE_BASE)
{
png_warning(png_ptr, "Invalid filter type specified");
filter_type = PNG_FILTER_TYPE_BASE;
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
if (interlace_type != PNG_INTERLACE_NONE &&
- interlace_type != PNG_INTERLACE_ADAM7)
+ interlace_type != PNG_INTERLACE_ADAM7)
{
png_warning(png_ptr, "Invalid interlace type specified");
interlace_type = PNG_INTERLACE_ADAM7;
interlace_type=PNG_INTERLACE_NONE;
#endif
- /* Save the relevent information */
+ /* Save the relevant information */
png_ptr->bit_depth = (png_byte)bit_depth;
png_ptr->color_type = (png_byte)color_type;
png_ptr->interlaced = (png_byte)interlace_type;
buf[12] = (png_byte)interlace_type;
/* Write the chunk */
- png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
+ png_write_complete_chunk(png_ptr, png_IHDR, buf, 13);
- /* Initialize zlib with PNG info */
- png_ptr->zstream.zalloc = png_zalloc;
- png_ptr->zstream.zfree = png_zfree;
- png_ptr->zstream.opaque = (voidpf)png_ptr;
- if (!(png_ptr->do_filter))
+ if ((png_ptr->do_filter) == PNG_NO_FILTERS)
{
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
- png_ptr->bit_depth < 8)
+ png_ptr->bit_depth < 8)
png_ptr->do_filter = PNG_FILTER_NONE;
+
else
png_ptr->do_filter = PNG_ALL_FILTERS;
}
- if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
- {
- if (png_ptr->do_filter != PNG_FILTER_NONE)
- png_ptr->zlib_strategy = Z_FILTERED;
- else
- png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
- }
- if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
- png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
- if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
- png_ptr->zlib_mem_level = 8;
- if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
- png_ptr->zlib_window_bits = 15;
- if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
- png_ptr->zlib_method = 8;
- ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
- png_ptr->zlib_method, png_ptr->zlib_window_bits,
- png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
- if (ret != Z_OK)
- {
- if (ret == Z_VERSION_ERROR) png_error(png_ptr,
- "zlib failed to initialize compressor -- version error");
- if (ret == Z_STREAM_ERROR) png_error(png_ptr,
- "zlib failed to initialize compressor -- stream error");
- if (ret == Z_MEM_ERROR) png_error(png_ptr,
- "zlib failed to initialize compressor -- mem error");
- png_error(png_ptr, "zlib failed to initialize compressor");
- }
- png_ptr->zstream.next_out = png_ptr->zbuf;
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- /* libpng is not interested in zstream.data_type */
- /* Set it to a predefined value, to avoid its evaluation inside zlib */
- png_ptr->zstream.data_type = Z_BINARY;
-
- png_ptr->mode = PNG_HAVE_IHDR;
+
+ png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */
}
/* Write the palette. We are careful not to trust png_color to be in the
* structure.
*/
void /* PRIVATE */
-png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
+png_write_PLTE(png_structrp png_ptr, png_const_colorp palette,
+ png_uint_32 num_pal)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_PLTE;
-#endif
- png_uint_32 i;
- png_colorp pal_ptr;
+ png_uint_32 max_palette_length, i;
+ png_const_colorp pal_ptr;
png_byte buf[3];
png_debug(1, "in png_write_PLTE");
+ max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
+ (1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
+
if ((
#ifdef PNG_MNG_FEATURES_SUPPORTED
- !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
+ (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 &&
#endif
- num_pal == 0) || num_pal > 256)
+ num_pal == 0) || num_pal > max_palette_length)
{
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_error(png_ptr, "Invalid number of colors in palette");
- }
- else
- {
- png_warning(png_ptr, "Invalid number of colors in palette");
- return;
- }
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_error(png_ptr, "Invalid number of colors in palette");
+ }
+
+ else
+ {
+ png_warning(png_ptr, "Invalid number of colors in palette");
+ return;
+ }
}
- if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
+ if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
{
png_warning(png_ptr,
- "Ignoring request to write a PLTE chunk in grayscale PNG");
+ "Ignoring request to write a PLTE chunk in grayscale PNG");
+
return;
}
png_ptr->num_palette = (png_uint_16)num_pal;
png_debug1(3, "num_palette = %d", png_ptr->num_palette);
- png_write_chunk_start(png_ptr, (png_bytep)png_PLTE,
- (png_uint_32)(num_pal * 3));
+ png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));
#ifdef PNG_POINTER_INDEXING_SUPPORTED
+
for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
{
buf[0] = pal_ptr->red;
buf[1] = pal_ptr->green;
buf[2] = pal_ptr->blue;
- png_write_chunk_data(png_ptr, buf, (png_size_t)3);
+ png_write_chunk_data(png_ptr, buf, 3);
}
+
#else
/* This is a little slower but some buggy compilers need to do this
* instead
*/
pal_ptr=palette;
+
for (i = 0; i < num_pal; i++)
{
buf[0] = pal_ptr[i].red;
buf[1] = pal_ptr[i].green;
buf[2] = pal_ptr[i].blue;
- png_write_chunk_data(png_ptr, buf, (png_size_t)3);
+ png_write_chunk_data(png_ptr, buf, 3);
}
+
#endif
png_write_chunk_end(png_ptr);
png_ptr->mode |= PNG_HAVE_PLTE;
}
-/* Write an IDAT chunk */
+/* This is similar to png_text_compress, above, except that it does not require
+ * all of the data at once and, instead of buffering the compressed result,
+ * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out
+ * because it calls the write interface. As a result it does its own error
+ * reporting and does not return an error code. In the event of error it will
+ * just call png_error. The input data length may exceed 32-bits. The 'flush'
+ * parameter is exactly the same as that to deflate, with the following
+ * meanings:
+ *
+ * Z_NO_FLUSH: normal incremental output of compressed data
+ * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush
+ * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up
+ *
+ * The routine manages the acquire and release of the png_ptr->zstream by
+ * checking and (at the end) clearing png_ptr->zowner; it does some sanity
+ * checks on the 'mode' flags while doing this.
+ */
void /* PRIVATE */
-png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
+png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
+ png_alloc_size_t input_len, int flush)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_IDAT;
-#endif
+ if (png_ptr->zowner != png_IDAT)
+ {
+ /* First time. Ensure we have a temporary buffer for compression and
+ * trim the buffer list if it has more than one entry to free memory.
+ * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been
+ * created at this point, but the check here is quick and safe.
+ */
+ if (png_ptr->zbuffer_list == NULL)
+ {
+ png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp,
+ png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
+ png_ptr->zbuffer_list->next = NULL;
+ }
- png_debug(1, "in png_write_IDAT");
+ else
+ png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next);
+
+ /* It is a terminal error if we can't claim the zstream. */
+ if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ /* The output state is maintained in png_ptr->zstream, so it must be
+ * initialized here after the claim.
+ */
+ png_ptr->zstream.next_out = png_ptr->zbuffer_list->output;
+ png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
+ }
- /* Optimize the CMF field in the zlib stream. */
- /* This hack of the zlib stream is compliant to the stream specification. */
- if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
- png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+ /* Now loop reading and writing until all the input is consumed or an error
+ * terminates the operation. The _out values are maintained across calls to
+ * this function, but the input must be reset each time.
+ */
+ png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
+ png_ptr->zstream.avail_in = 0; /* set below */
+ for (;;)
{
- unsigned int z_cmf = data[0]; /* zlib compression method and flags */
- if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+ int ret;
+
+ /* INPUT: from the row data */
+ uInt avail = ZLIB_IO_MAX;
+
+ if (avail > input_len)
+ avail = (uInt)input_len; /* safe because of the check */
+
+ png_ptr->zstream.avail_in = avail;
+ input_len -= avail;
+
+ ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush);
+
+ /* Include as-yet unconsumed input */
+ input_len += png_ptr->zstream.avail_in;
+ png_ptr->zstream.avail_in = 0;
+
+ /* OUTPUT: write complete IDAT chunks when avail_out drops to zero. Note
+ * that these two zstream fields are preserved across the calls, therefore
+ * there is no need to set these up on entry to the loop.
+ */
+ if (png_ptr->zstream.avail_out == 0)
+ {
+ png_bytep data = png_ptr->zbuffer_list->output;
+ uInt size = png_ptr->zbuffer_size;
+
+ /* Write an IDAT containing the data then reset the buffer. The
+ * first IDAT may need deflate header optimization.
+ */
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 &&
+ png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+ optimize_cmf(data, png_image_size(png_ptr));
+#endif
+
+ if (size > 0)
+ png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+ png_ptr->mode |= PNG_HAVE_IDAT;
+
+ png_ptr->zstream.next_out = data;
+ png_ptr->zstream.avail_out = size;
+
+ /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with
+ * the same flush parameter until it has finished output, for NO_FLUSH
+ * it doesn't matter.
+ */
+ if (ret == Z_OK && flush != Z_NO_FLUSH)
+ continue;
+ }
+
+ /* The order of these checks doesn't matter much; it just affects which
+ * possible error might be detected if multiple things go wrong at once.
+ */
+ if (ret == Z_OK) /* most likely return code! */
{
- /* Avoid memory underflows and multiplication overflows.
- *
- * The conditions below are practically always satisfied;
- * however, they still must be checked.
+ /* If all the input has been consumed then just return. If Z_FINISH
+ * was used as the flush parameter something has gone wrong if we get
+ * here.
*/
- if (length >= 2 &&
- png_ptr->height < 16384 && png_ptr->width < 16384)
+ if (input_len == 0)
{
- png_uint_32 uncompressed_idat_size = png_ptr->height *
- ((png_ptr->width *
- png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
- unsigned int z_cinfo = z_cmf >> 4;
- unsigned int half_z_window_size = 1 << (z_cinfo + 7);
- while (uncompressed_idat_size <= half_z_window_size &&
- half_z_window_size >= 256)
- {
- z_cinfo--;
- half_z_window_size >>= 1;
- }
- z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
- if (data[0] != (png_byte)z_cmf)
- {
- data[0] = (png_byte)z_cmf;
- data[1] &= 0xe0;
- data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f);
- }
+ if (flush == Z_FINISH)
+ png_error(png_ptr, "Z_OK on Z_FINISH with output space");
+
+ return;
}
}
+
+ else if (ret == Z_STREAM_END && flush == Z_FINISH)
+ {
+ /* This is the end of the IDAT data; any pending output must be
+ * flushed. For small PNG files we may still be at the beginning.
+ */
+ png_bytep data = png_ptr->zbuffer_list->output;
+ uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out;
+
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 &&
+ png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+ optimize_cmf(data, png_image_size(png_ptr));
+#endif
+
+ if (size > 0)
+ png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+ png_ptr->zstream.avail_out = 0;
+ png_ptr->zstream.next_out = NULL;
+ png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT;
+
+ png_ptr->zowner = 0; /* Release the stream */
+ return;
+ }
+
else
- png_error(png_ptr,
- "Invalid zlib compression method or flags in IDAT");
+ {
+ /* This is an error condition. */
+ png_zstream_error(png_ptr, ret);
+ png_error(png_ptr, png_ptr->zstream.msg);
+ }
}
-
- png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
- png_ptr->mode |= PNG_HAVE_IDAT;
}
/* Write an IEND chunk */
void /* PRIVATE */
-png_write_IEND(png_structp png_ptr)
+png_write_IEND(png_structrp png_ptr)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_IEND;
-#endif
-
png_debug(1, "in png_write_IEND");
- png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,
- (png_size_t)0);
+ png_write_complete_chunk(png_ptr, png_IEND, NULL, 0);
png_ptr->mode |= PNG_HAVE_IEND;
}
#ifdef PNG_WRITE_gAMA_SUPPORTED
/* Write a gAMA chunk */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-void /* PRIVATE */
-png_write_gAMA(png_structp png_ptr, double file_gamma)
-{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_gAMA;
-#endif
- png_uint_32 igamma;
- png_byte buf[4];
-
- png_debug(1, "in png_write_gAMA");
-
- /* file_gamma is saved in 1/100,000ths */
- igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
- png_save_uint_32(buf, igamma);
- png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
-}
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED
void /* PRIVATE */
-png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
+png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_gAMA;
-#endif
png_byte buf[4];
png_debug(1, "in png_write_gAMA");
/* file_gamma is saved in 1/100,000ths */
png_save_uint_32(buf, (png_uint_32)file_gamma);
- png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
+ png_write_complete_chunk(png_ptr, png_gAMA, buf, 4);
}
#endif
-#endif
#ifdef PNG_WRITE_sRGB_SUPPORTED
/* Write a sRGB chunk */
void /* PRIVATE */
-png_write_sRGB(png_structp png_ptr, int srgb_intent)
+png_write_sRGB(png_structrp png_ptr, int srgb_intent)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_sRGB;
-#endif
png_byte buf[1];
png_debug(1, "in png_write_sRGB");
if (srgb_intent >= PNG_sRGB_INTENT_LAST)
- png_warning(png_ptr,
- "Invalid sRGB rendering intent specified");
+ png_warning(png_ptr,
+ "Invalid sRGB rendering intent specified");
+
buf[0]=(png_byte)srgb_intent;
- png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
+ png_write_complete_chunk(png_ptr, png_sRGB, buf, 1);
}
#endif
#ifdef PNG_WRITE_iCCP_SUPPORTED
/* Write an iCCP chunk */
void /* PRIVATE */
-png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
- png_charp profile, int profile_len)
+png_write_iCCP(png_structrp png_ptr, png_const_charp name,
+ png_const_bytep profile)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_iCCP;
-#endif
- png_size_t name_len;
- png_charp new_name;
+ png_uint_32 name_len;
+ png_uint_32 profile_len;
+ png_byte new_name[81]; /* 1 byte for the compression byte */
compression_state comp;
- int embedded_profile_len = 0;
+ png_uint_32 temp;
png_debug(1, "in png_write_iCCP");
- comp.num_output_ptr = 0;
- comp.max_output_ptr = 0;
- comp.output_ptr = NULL;
- comp.input = NULL;
- comp.input_len = 0;
-
- if ((name_len = png_check_keyword(png_ptr, name,
- &new_name)) == 0)
- return;
+ /* These are all internal problems: the profile should have been checked
+ * before when it was stored.
+ */
+ if (profile == NULL)
+ png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */
- if (compression_type != PNG_COMPRESSION_TYPE_BASE)
- png_warning(png_ptr, "Unknown compression type in iCCP chunk");
+ profile_len = png_get_uint_32(profile);
- if (profile == NULL)
- profile_len = 0;
+ if (profile_len < 132)
+ png_error(png_ptr, "ICC profile too short");
- if (profile_len > 3)
- embedded_profile_len =
- ((*( (png_bytep)profile ))<<24) |
- ((*( (png_bytep)profile + 1))<<16) |
- ((*( (png_bytep)profile + 2))<< 8) |
- ((*( (png_bytep)profile + 3)) );
+ temp = (png_uint_32) (*(profile+8));
+ if (temp > 3 && (profile_len & 0x03))
+ png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)");
- if (embedded_profile_len < 0)
{
- png_warning(png_ptr,
- "Embedded profile length in iCCP chunk is negative");
- png_free(png_ptr, new_name);
- return;
- }
+ png_uint_32 embedded_profile_len = png_get_uint_32(profile);
- if (profile_len < embedded_profile_len)
- {
- png_warning(png_ptr,
- "Embedded profile length too large in iCCP chunk");
- png_free(png_ptr, new_name);
- return;
+ if (profile_len != embedded_profile_len)
+ png_error(png_ptr, "Profile length does not match profile");
}
- if (profile_len > embedded_profile_len)
- {
- png_warning(png_ptr,
- "Truncating profile to actual length in iCCP chunk");
- profile_len = embedded_profile_len;
- }
+ name_len = png_check_keyword(png_ptr, name, new_name);
- if (profile_len)
- profile_len = png_text_compress(png_ptr, profile,
- (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
+ if (name_len == 0)
+ png_error(png_ptr, "iCCP: invalid keyword");
+
+ new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE;
/* Make sure we include the NULL after the name and the compression type */
- png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
- (png_uint_32)(name_len + profile_len + 2));
- new_name[name_len + 1] = 0x00;
- png_write_chunk_data(png_ptr, (png_bytep)new_name,
- (png_size_t)(name_len + 2));
+ ++name_len;
- if (profile_len)
- png_write_compressed_data_out(png_ptr, &comp);
+ png_text_compress_init(&comp, profile, profile_len);
+
+ /* Allow for keyword terminator and compression byte */
+ if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len);
+
+ png_write_chunk_data(png_ptr, new_name, name_len);
+
+ png_write_compressed_data_out(png_ptr, &comp);
png_write_chunk_end(png_ptr);
- png_free(png_ptr, new_name);
}
#endif
#ifdef PNG_WRITE_sPLT_SUPPORTED
/* Write a sPLT chunk */
void /* PRIVATE */
-png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
+png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_sPLT;
-#endif
- png_size_t name_len;
- png_charp new_name;
+ png_uint_32 name_len;
+ png_byte new_name[80];
png_byte entrybuf[10];
- int entry_size = (spalette->depth == 8 ? 6 : 10);
- int palette_size = entry_size * spalette->nentries;
+ size_t entry_size = (spalette->depth == 8 ? 6 : 10);
+ size_t palette_size = entry_size * (size_t)spalette->nentries;
png_sPLT_entryp ep;
#ifndef PNG_POINTER_INDEXING_SUPPORTED
int i;
png_debug(1, "in png_write_sPLT");
- if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)
- return;
+ name_len = png_check_keyword(png_ptr, spalette->name, new_name);
+
+ if (name_len == 0)
+ png_error(png_ptr, "sPLT: invalid keyword");
/* Make sure we include the NULL after the name */
- png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
- (png_uint_32)(name_len + 2 + palette_size));
- png_write_chunk_data(png_ptr, (png_bytep)new_name,
- (png_size_t)(name_len + 1));
- png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, (png_size_t)1);
+ png_write_chunk_header(png_ptr, png_sPLT,
+ (png_uint_32)(name_len + 2 + palette_size));
+
+ png_write_chunk_data(png_ptr, (png_bytep)new_name, (size_t)(name_len + 1));
+
+ png_write_chunk_data(png_ptr, &spalette->depth, 1);
/* Loop through each palette entry, writing appropriately */
#ifdef PNG_POINTER_INDEXING_SUPPORTED
{
if (spalette->depth == 8)
{
- entrybuf[0] = (png_byte)ep->red;
- entrybuf[1] = (png_byte)ep->green;
- entrybuf[2] = (png_byte)ep->blue;
- entrybuf[3] = (png_byte)ep->alpha;
- png_save_uint_16(entrybuf + 4, ep->frequency);
+ entrybuf[0] = (png_byte)ep->red;
+ entrybuf[1] = (png_byte)ep->green;
+ entrybuf[2] = (png_byte)ep->blue;
+ entrybuf[3] = (png_byte)ep->alpha;
+ png_save_uint_16(entrybuf + 4, ep->frequency);
}
+
else
{
- png_save_uint_16(entrybuf + 0, ep->red);
- png_save_uint_16(entrybuf + 2, ep->green);
- png_save_uint_16(entrybuf + 4, ep->blue);
- png_save_uint_16(entrybuf + 6, ep->alpha);
- png_save_uint_16(entrybuf + 8, ep->frequency);
+ png_save_uint_16(entrybuf + 0, ep->red);
+ png_save_uint_16(entrybuf + 2, ep->green);
+ png_save_uint_16(entrybuf + 4, ep->blue);
+ png_save_uint_16(entrybuf + 6, ep->alpha);
+ png_save_uint_16(entrybuf + 8, ep->frequency);
}
- png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
+
+ png_write_chunk_data(png_ptr, entrybuf, entry_size);
}
#else
ep=spalette->entries;
- for (i=0; i>spalette->nentries; i++)
+ for (i = 0; i>spalette->nentries; i++)
{
if (spalette->depth == 8)
{
- entrybuf[0] = (png_byte)ep[i].red;
- entrybuf[1] = (png_byte)ep[i].green;
- entrybuf[2] = (png_byte)ep[i].blue;
- entrybuf[3] = (png_byte)ep[i].alpha;
- png_save_uint_16(entrybuf + 4, ep[i].frequency);
+ entrybuf[0] = (png_byte)ep[i].red;
+ entrybuf[1] = (png_byte)ep[i].green;
+ entrybuf[2] = (png_byte)ep[i].blue;
+ entrybuf[3] = (png_byte)ep[i].alpha;
+ png_save_uint_16(entrybuf + 4, ep[i].frequency);
}
+
else
{
- png_save_uint_16(entrybuf + 0, ep[i].red);
- png_save_uint_16(entrybuf + 2, ep[i].green);
- png_save_uint_16(entrybuf + 4, ep[i].blue);
- png_save_uint_16(entrybuf + 6, ep[i].alpha);
- png_save_uint_16(entrybuf + 8, ep[i].frequency);
+ png_save_uint_16(entrybuf + 0, ep[i].red);
+ png_save_uint_16(entrybuf + 2, ep[i].green);
+ png_save_uint_16(entrybuf + 4, ep[i].blue);
+ png_save_uint_16(entrybuf + 6, ep[i].alpha);
+ png_save_uint_16(entrybuf + 8, ep[i].frequency);
}
- png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
+
+ png_write_chunk_data(png_ptr, entrybuf, entry_size);
}
#endif
png_write_chunk_end(png_ptr);
- png_free(png_ptr, new_name);
}
#endif
#ifdef PNG_WRITE_sBIT_SUPPORTED
/* Write the sBIT chunk */
void /* PRIVATE */
-png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
+png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_sBIT;
-#endif
png_byte buf[4];
- png_size_t size;
+ size_t size;
png_debug(1, "in png_write_sBIT");
/* Make sure we don't depend upon the order of PNG_COLOR_8 */
- if (color_type & PNG_COLOR_MASK_COLOR)
+ if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
{
png_byte maxbits;
maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
- png_ptr->usr_bit_depth);
+ png_ptr->usr_bit_depth);
+
if (sbit->red == 0 || sbit->red > maxbits ||
sbit->green == 0 || sbit->green > maxbits ||
sbit->blue == 0 || sbit->blue > maxbits)
png_warning(png_ptr, "Invalid sBIT depth specified");
return;
}
+
buf[0] = sbit->red;
buf[1] = sbit->green;
buf[2] = sbit->blue;
size = 3;
}
+
else
{
if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
png_warning(png_ptr, "Invalid sBIT depth specified");
return;
}
+
buf[0] = sbit->gray;
size = 1;
}
- if (color_type & PNG_COLOR_MASK_ALPHA)
+ if ((color_type & PNG_COLOR_MASK_ALPHA) != 0)
{
if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
{
png_warning(png_ptr, "Invalid sBIT depth specified");
return;
}
+
buf[size++] = sbit->alpha;
}
- png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
+ png_write_complete_chunk(png_ptr, png_sBIT, buf, size);
}
#endif
#ifdef PNG_WRITE_cHRM_SUPPORTED
/* Write the cHRM chunk */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-void /* PRIVATE */
-png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
- double red_x, double red_y, double green_x, double green_y,
- double blue_x, double blue_y)
-{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_cHRM;
-#endif
- png_byte buf[32];
-
- png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y,
- int_green_x, int_green_y, int_blue_x, int_blue_y;
-
- png_debug(1, "in png_write_cHRM");
-
- int_white_x = (png_uint_32)(white_x * 100000.0 + 0.5);
- int_white_y = (png_uint_32)(white_y * 100000.0 + 0.5);
- int_red_x = (png_uint_32)(red_x * 100000.0 + 0.5);
- int_red_y = (png_uint_32)(red_y * 100000.0 + 0.5);
- int_green_x = (png_uint_32)(green_x * 100000.0 + 0.5);
- int_green_y = (png_uint_32)(green_y * 100000.0 + 0.5);
- int_blue_x = (png_uint_32)(blue_x * 100000.0 + 0.5);
- int_blue_y = (png_uint_32)(blue_y * 100000.0 + 0.5);
-
-#ifdef PNG_CHECK_cHRM_SUPPORTED
- if (png_check_cHRM_fixed(png_ptr, int_white_x, int_white_y,
- int_red_x, int_red_y, int_green_x, int_green_y, int_blue_x, int_blue_y))
-#endif
- {
- /* Each value is saved in 1/100,000ths */
-
- png_save_uint_32(buf, int_white_x);
- png_save_uint_32(buf + 4, int_white_y);
-
- png_save_uint_32(buf + 8, int_red_x);
- png_save_uint_32(buf + 12, int_red_y);
-
- png_save_uint_32(buf + 16, int_green_x);
- png_save_uint_32(buf + 20, int_green_y);
-
- png_save_uint_32(buf + 24, int_blue_x);
- png_save_uint_32(buf + 28, int_blue_y);
-
- png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
- }
-}
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED
void /* PRIVATE */
-png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
- png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
- png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
- png_fixed_point blue_y)
+png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_cHRM;
-#endif
png_byte buf[32];
png_debug(1, "in png_write_cHRM");
/* Each value is saved in 1/100,000ths */
-#ifdef PNG_CHECK_cHRM_SUPPORTED
- if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,
- green_x, green_y, blue_x, blue_y))
-#endif
- {
- png_save_uint_32(buf, (png_uint_32)white_x);
- png_save_uint_32(buf + 4, (png_uint_32)white_y);
+ png_save_int_32(buf, xy->whitex);
+ png_save_int_32(buf + 4, xy->whitey);
- png_save_uint_32(buf + 8, (png_uint_32)red_x);
- png_save_uint_32(buf + 12, (png_uint_32)red_y);
+ png_save_int_32(buf + 8, xy->redx);
+ png_save_int_32(buf + 12, xy->redy);
- png_save_uint_32(buf + 16, (png_uint_32)green_x);
- png_save_uint_32(buf + 20, (png_uint_32)green_y);
+ png_save_int_32(buf + 16, xy->greenx);
+ png_save_int_32(buf + 20, xy->greeny);
- png_save_uint_32(buf + 24, (png_uint_32)blue_x);
- png_save_uint_32(buf + 28, (png_uint_32)blue_y);
+ png_save_int_32(buf + 24, xy->bluex);
+ png_save_int_32(buf + 28, xy->bluey);
- png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
- }
+ png_write_complete_chunk(png_ptr, png_cHRM, buf, 32);
}
#endif
-#endif
#ifdef PNG_WRITE_tRNS_SUPPORTED
/* Write the tRNS chunk */
void /* PRIVATE */
-png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
- int num_trans, int color_type)
+png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
+ png_const_color_16p tran, int num_trans, int color_type)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_tRNS;
-#endif
png_byte buf[6];
png_debug(1, "in png_write_tRNS");
{
if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
{
- png_warning(png_ptr, "Invalid number of transparent colors specified");
+ png_app_warning(png_ptr,
+ "Invalid number of transparent colors specified");
return;
}
+
/* Write the chunk out as it is */
- png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans,
- (png_size_t)num_trans);
+ png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,
+ (size_t)num_trans);
}
+
else if (color_type == PNG_COLOR_TYPE_GRAY)
{
- /* One 16 bit value */
+ /* One 16-bit value */
if (tran->gray >= (1 << png_ptr->bit_depth))
{
- png_warning(png_ptr,
- "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
+ png_app_warning(png_ptr,
+ "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
+
return;
}
+
png_save_uint_16(buf, tran->gray);
- png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
+ png_write_complete_chunk(png_ptr, png_tRNS, buf, 2);
}
+
else if (color_type == PNG_COLOR_TYPE_RGB)
{
- /* Three 16 bit values */
+ /* Three 16-bit values */
png_save_uint_16(buf, tran->red);
png_save_uint_16(buf + 2, tran->green);
png_save_uint_16(buf + 4, tran->blue);
- if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0)
+#else
+ if ((buf[0] | buf[2] | buf[4]) != 0)
+#endif
{
- png_warning(png_ptr,
- "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
+ png_app_warning(png_ptr,
+ "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
return;
}
- png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
+
+ png_write_complete_chunk(png_ptr, png_tRNS, buf, 6);
}
+
else
{
- png_warning(png_ptr, "Can't write tRNS with an alpha channel");
+ png_app_warning(png_ptr, "Can't write tRNS with an alpha channel");
}
}
#endif
#ifdef PNG_WRITE_bKGD_SUPPORTED
/* Write the background chunk */
void /* PRIVATE */
-png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
+png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_bKGD;
-#endif
png_byte buf[6];
png_debug(1, "in png_write_bKGD");
{
if (
#ifdef PNG_MNG_FEATURES_SUPPORTED
- (png_ptr->num_palette ||
- (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
+ (png_ptr->num_palette != 0 ||
+ (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0) &&
#endif
back->index >= png_ptr->num_palette)
{
png_warning(png_ptr, "Invalid background palette index");
return;
}
+
buf[0] = back->index;
- png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
+ png_write_complete_chunk(png_ptr, png_bKGD, buf, 1);
}
- else if (color_type & PNG_COLOR_MASK_COLOR)
+
+ else if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
{
png_save_uint_16(buf, back->red);
png_save_uint_16(buf + 2, back->green);
png_save_uint_16(buf + 4, back->blue);
- if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0)
+#else
+ if ((buf[0] | buf[2] | buf[4]) != 0)
+#endif
{
png_warning(png_ptr,
- "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
+ "Ignoring attempt to write 16-bit bKGD chunk "
+ "when bit_depth is 8");
+
return;
}
- png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
+
+ png_write_complete_chunk(png_ptr, png_bKGD, buf, 6);
}
+
else
{
if (back->gray >= (1 << png_ptr->bit_depth))
{
png_warning(png_ptr,
- "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
+ "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
+
return;
}
+
png_save_uint_16(buf, back->gray);
- png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
+ png_write_complete_chunk(png_ptr, png_bKGD, buf, 2);
}
}
#endif
-#ifdef PNG_WRITE_hIST_SUPPORTED
-/* Write the histogram */
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+/* Write the Exif data */
void /* PRIVATE */
-png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
+png_write_eXIf(png_structrp png_ptr, png_bytep exif, int num_exif)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_hIST;
-#endif
int i;
- png_byte buf[3];
+ png_byte buf[1];
- png_debug(1, "in png_write_hIST");
+ png_debug(1, "in png_write_eXIf");
- if (num_hist > (int)png_ptr->num_palette)
- {
- png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
- png_ptr->num_palette);
- png_warning(png_ptr, "Invalid number of histogram entries specified");
- return;
- }
+ png_write_chunk_header(png_ptr, png_eXIf, (png_uint_32)(num_exif));
- png_write_chunk_start(png_ptr, (png_bytep)png_hIST,
- (png_uint_32)(num_hist * 2));
- for (i = 0; i < num_hist; i++)
+ for (i = 0; i < num_exif; i++)
{
- png_save_uint_16(buf, hist[i]);
- png_write_chunk_data(png_ptr, buf, (png_size_t)2);
+ buf[0] = exif[i];
+ png_write_chunk_data(png_ptr, buf, 1);
}
+
png_write_chunk_end(png_ptr);
}
#endif
-#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
- defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
-/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
- * and if invalid, correct the keyword rather than discarding the entire
- * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
- * length, forbids leading or trailing whitespace, multiple internal spaces,
- * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
- *
- * The new_key is allocated to hold the corrected keyword and must be freed
- * by the calling routine. This avoids problems with trying to write to
- * static keywords without having to have duplicate copies of the strings.
- */
-png_size_t /* PRIVATE */
-png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
+#ifdef PNG_WRITE_hIST_SUPPORTED
+/* Write the histogram */
+void /* PRIVATE */
+png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist)
{
- png_size_t key_len;
- png_charp kp, dp;
- int kflag;
- int kwarn=0;
-
- png_debug(1, "in png_check_keyword");
-
- *new_key = NULL;
-
- if (key == NULL || (key_len = png_strlen(key)) == 0)
- {
- png_warning(png_ptr, "zero length keyword");
- return ((png_size_t)0);
- }
-
- png_debug1(2, "Keyword to be checked is '%s'", key);
-
- *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
- if (*new_key == NULL)
- {
- png_warning(png_ptr, "Out of memory while procesing keyword");
- return ((png_size_t)0);
- }
-
- /* Replace non-printing characters with a blank and print a warning */
- for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
- {
- if ((png_byte)*kp < 0x20 ||
- ((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1))
- {
-#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
- char msg[40];
-
- png_snprintf(msg, 40,
- "invalid keyword character 0x%02X", (png_byte)*kp);
- png_warning(png_ptr, msg);
-#else
- png_warning(png_ptr, "invalid character in keyword");
-#endif
- *dp = ' ';
- }
- else
- {
- *dp = *kp;
- }
- }
- *dp = '\0';
-
- /* Remove any trailing white space. */
- kp = *new_key + key_len - 1;
- if (*kp == ' ')
- {
- png_warning(png_ptr, "trailing spaces removed from keyword");
+ int i;
+ png_byte buf[3];
- while (*kp == ' ')
- {
- *(kp--) = '\0';
- key_len--;
- }
- }
+ png_debug(1, "in png_write_hIST");
- /* Remove any leading white space. */
- kp = *new_key;
- if (*kp == ' ')
+ if (num_hist > (int)png_ptr->num_palette)
{
- png_warning(png_ptr, "leading spaces removed from keyword");
-
- while (*kp == ' ')
- {
- kp++;
- key_len--;
- }
- }
-
- png_debug1(2, "Checking for multiple internal spaces in '%s'", kp);
+ png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
+ png_ptr->num_palette);
- /* Remove multiple internal spaces. */
- for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
- {
- if (*kp == ' ' && kflag == 0)
- {
- *(dp++) = *kp;
- kflag = 1;
- }
- else if (*kp == ' ')
- {
- key_len--;
- kwarn=1;
- }
- else
- {
- *(dp++) = *kp;
- kflag = 0;
- }
+ png_warning(png_ptr, "Invalid number of histogram entries specified");
+ return;
}
- *dp = '\0';
- if (kwarn)
- png_warning(png_ptr, "extra interior spaces removed from keyword");
- if (key_len == 0)
- {
- png_free(png_ptr, *new_key);
- *new_key=NULL;
- png_warning(png_ptr, "Zero length keyword");
- }
+ png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
- if (key_len > 79)
+ for (i = 0; i < num_hist; i++)
{
- png_warning(png_ptr, "keyword length must be 1 - 79 characters");
- (*new_key)[79] = '\0';
- key_len = 79;
+ png_save_uint_16(buf, hist[i]);
+ png_write_chunk_data(png_ptr, buf, 2);
}
- return (key_len);
+ png_write_chunk_end(png_ptr);
}
#endif
#ifdef PNG_WRITE_tEXt_SUPPORTED
/* Write a tEXt chunk */
void /* PRIVATE */
-png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
- png_size_t text_len)
+png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
+ size_t text_len)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_tEXt;
-#endif
- png_size_t key_len;
- png_charp new_key;
+ png_uint_32 key_len;
+ png_byte new_key[80];
png_debug(1, "in png_write_tEXt");
- if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
- return;
+ key_len = png_check_keyword(png_ptr, key, new_key);
+
+ if (key_len == 0)
+ png_error(png_ptr, "tEXt: invalid keyword");
if (text == NULL || *text == '\0')
text_len = 0;
+
else
- text_len = png_strlen(text);
+ text_len = strlen(text);
+
+ if (text_len > PNG_UINT_31_MAX - (key_len+1))
+ png_error(png_ptr, "tEXt: text too long");
/* Make sure we include the 0 after the key */
- png_write_chunk_start(png_ptr, (png_bytep)png_tEXt,
- (png_uint_32)(key_len + text_len + 1));
+ png_write_chunk_header(png_ptr, png_tEXt,
+ (png_uint_32)/*checked above*/(key_len + text_len + 1));
/*
* We leave it to the application to meet PNG-1.0 requirements on the
* contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
* any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
* The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
*/
- png_write_chunk_data(png_ptr, (png_bytep)new_key,
- (png_size_t)(key_len + 1));
- if (text_len)
- png_write_chunk_data(png_ptr, (png_bytep)text, (png_size_t)text_len);
+ png_write_chunk_data(png_ptr, new_key, key_len + 1);
+
+ if (text_len != 0)
+ png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len);
png_write_chunk_end(png_ptr);
- png_free(png_ptr, new_key);
}
#endif
#ifdef PNG_WRITE_zTXt_SUPPORTED
/* Write a compressed text chunk */
void /* PRIVATE */
-png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
- png_size_t text_len, int compression)
+png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
+ int compression)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_zTXt;
-#endif
- png_size_t key_len;
- char buf[1];
- png_charp new_key;
+ png_uint_32 key_len;
+ png_byte new_key[81];
compression_state comp;
png_debug(1, "in png_write_zTXt");
- comp.num_output_ptr = 0;
- comp.max_output_ptr = 0;
- comp.output_ptr = NULL;
- comp.input = NULL;
- comp.input_len = 0;
-
- if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
+ if (compression == PNG_TEXT_COMPRESSION_NONE)
{
- png_free(png_ptr, new_key);
+ png_write_tEXt(png_ptr, key, text, 0);
return;
}
- if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
- {
- png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
- png_free(png_ptr, new_key);
- return;
- }
+ if (compression != PNG_TEXT_COMPRESSION_zTXt)
+ png_error(png_ptr, "zTXt: invalid compression type");
- text_len = png_strlen(text);
+ key_len = png_check_keyword(png_ptr, key, new_key);
+
+ if (key_len == 0)
+ png_error(png_ptr, "zTXt: invalid keyword");
+
+ /* Add the compression method and 1 for the keyword separator. */
+ new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
+ ++key_len;
/* Compute the compressed data; do it now for the length */
- text_len = png_text_compress(png_ptr, text, text_len, compression,
- &comp);
+ png_text_compress_init(&comp, (png_const_bytep)text,
+ text == NULL ? 0 : strlen(text));
+
+ if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
/* Write start of chunk */
- png_write_chunk_start(png_ptr, (png_bytep)png_zTXt,
- (png_uint_32)(key_len+text_len + 2));
+ png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len);
+
/* Write key */
- png_write_chunk_data(png_ptr, (png_bytep)new_key,
- (png_size_t)(key_len + 1));
- png_free(png_ptr, new_key);
+ png_write_chunk_data(png_ptr, new_key, key_len);
- buf[0] = (png_byte)compression;
- /* Write compression */
- png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);
/* Write the compressed data */
png_write_compressed_data_out(png_ptr, &comp);
#ifdef PNG_WRITE_iTXt_SUPPORTED
/* Write an iTXt chunk */
void /* PRIVATE */
-png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
- png_charp lang, png_charp lang_key, png_charp text)
+png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
+ png_const_charp lang, png_const_charp lang_key, png_const_charp text)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_iTXt;
-#endif
- png_size_t lang_len, key_len, lang_key_len, text_len;
- png_charp new_lang;
- png_charp new_key = NULL;
- png_byte cbuf[2];
+ png_uint_32 key_len, prefix_len;
+ size_t lang_len, lang_key_len;
+ png_byte new_key[82];
compression_state comp;
png_debug(1, "in png_write_iTXt");
- comp.num_output_ptr = 0;
- comp.max_output_ptr = 0;
- comp.output_ptr = NULL;
- comp.input = NULL;
+ key_len = png_check_keyword(png_ptr, key, new_key);
- if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
- return;
+ if (key_len == 0)
+ png_error(png_ptr, "iTXt: invalid keyword");
- if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
+ /* Set the compression flag */
+ switch (compression)
{
- png_warning(png_ptr, "Empty language field in iTXt chunk");
- new_lang = NULL;
- lang_len = 0;
+ case PNG_ITXT_COMPRESSION_NONE:
+ case PNG_TEXT_COMPRESSION_NONE:
+ compression = new_key[++key_len] = 0; /* no compression */
+ break;
+
+ case PNG_TEXT_COMPRESSION_zTXt:
+ case PNG_ITXT_COMPRESSION_zTXt:
+ compression = new_key[++key_len] = 1; /* compressed */
+ break;
+
+ default:
+ png_error(png_ptr, "iTXt: invalid compression");
}
- if (lang_key == NULL)
- lang_key_len = 0;
+ new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
+ ++key_len; /* for the keywod separator */
+
+ /* We leave it to the application to meet PNG-1.0 requirements on the
+ * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
+ * any non-Latin-1 characters except for NEWLINE. ISO PNG, however,
+ * specifies that the text is UTF-8 and this really doesn't require any
+ * checking.
+ *
+ * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+ *
+ * TODO: validate the language tag correctly (see the spec.)
+ */
+ if (lang == NULL) lang = ""; /* empty language is valid */
+ lang_len = strlen(lang)+1;
+ if (lang_key == NULL) lang_key = ""; /* may be empty */
+ lang_key_len = strlen(lang_key)+1;
+ if (text == NULL) text = ""; /* may be empty */
+
+ prefix_len = key_len;
+ if (lang_len > PNG_UINT_31_MAX-prefix_len)
+ prefix_len = PNG_UINT_31_MAX;
else
- lang_key_len = png_strlen(lang_key);
+ prefix_len = (png_uint_32)(prefix_len + lang_len);
- if (text == NULL)
- text_len = 0;
+ if (lang_key_len > PNG_UINT_31_MAX-prefix_len)
+ prefix_len = PNG_UINT_31_MAX;
else
- text_len = png_strlen(text);
+ prefix_len = (png_uint_32)(prefix_len + lang_key_len);
- /* Compute the compressed data; do it now for the length */
- text_len = png_text_compress(png_ptr, text, text_len, compression-2,
- &comp);
+ png_text_compress_init(&comp, (png_const_bytep)text, strlen(text));
+ if (compression != 0)
+ {
+ if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg);
+ }
- /* Make sure we include the compression flag, the compression byte,
- * and the NULs after the key, lang, and lang_key parts */
+ else
+ {
+ if (comp.input_len > PNG_UINT_31_MAX-prefix_len)
+ png_error(png_ptr, "iTXt: uncompressed text too long");
- png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
- (png_uint_32)(
- 5 /* comp byte, comp flag, terminators for key, lang and lang_key */
- + key_len
- + lang_len
- + lang_key_len
- + text_len));
+ /* So the string will fit in a chunk: */
+ comp.output_len = (png_uint_32)/*SAFE*/comp.input_len;
+ }
- /* We leave it to the application to meet PNG-1.0 requirements on the
- * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
- * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
- * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
- */
- png_write_chunk_data(png_ptr, (png_bytep)new_key,
- (png_size_t)(key_len + 1));
+ png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len);
- /* Set the compression flag */
- if (compression == PNG_ITXT_COMPRESSION_NONE || \
- compression == PNG_TEXT_COMPRESSION_NONE)
- cbuf[0] = 0;
- else /* compression == PNG_ITXT_COMPRESSION_zTXt */
- cbuf[0] = 1;
- /* Set the compression method */
- cbuf[1] = 0;
- png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);
-
- cbuf[0] = 0;
- png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf),
- (png_size_t)(lang_len + 1));
- png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf),
- (png_size_t)(lang_key_len + 1));
- png_write_compressed_data_out(png_ptr, &comp);
+ png_write_chunk_data(png_ptr, new_key, key_len);
+
+ png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len);
+
+ png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len);
+
+ if (compression != 0)
+ png_write_compressed_data_out(png_ptr, &comp);
+
+ else
+ png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.output_len);
png_write_chunk_end(png_ptr);
- png_free(png_ptr, new_key);
- png_free(png_ptr, new_lang);
}
#endif
#ifdef PNG_WRITE_oFFs_SUPPORTED
/* Write the oFFs chunk */
void /* PRIVATE */
-png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
- int unit_type)
+png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
+ int unit_type)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_oFFs;
-#endif
png_byte buf[9];
png_debug(1, "in png_write_oFFs");
png_save_int_32(buf + 4, y_offset);
buf[8] = (png_byte)unit_type;
- png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
+ png_write_complete_chunk(png_ptr, png_oFFs, buf, 9);
}
#endif
#ifdef PNG_WRITE_pCAL_SUPPORTED
/* Write the pCAL chunk (described in the PNG extensions document) */
void /* PRIVATE */
-png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
- png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
+png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0,
+ png_int_32 X1, int type, int nparams, png_const_charp units,
+ png_charpp params)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_pCAL;
-#endif
- png_size_t purpose_len, units_len, total_len;
- png_uint_32p params_len;
+ png_uint_32 purpose_len;
+ size_t units_len, total_len;
+ png_size_tp params_len;
png_byte buf[10];
- png_charp new_purpose;
+ png_byte new_purpose[80];
int i;
png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
if (type >= PNG_EQUATION_LAST)
- png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
+ png_error(png_ptr, "Unrecognized equation type for pCAL chunk");
+
+ purpose_len = png_check_keyword(png_ptr, purpose, new_purpose);
+
+ if (purpose_len == 0)
+ png_error(png_ptr, "pCAL: invalid keyword");
+
+ ++purpose_len; /* terminator */
- purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
- units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
+ units_len = strlen(units) + (nparams == 0 ? 0 : 1);
png_debug1(3, "pCAL units length = %d", (int)units_len);
total_len = purpose_len + units_len + 10;
- params_len = (png_uint_32p)png_malloc(png_ptr,
- (png_uint_32)(nparams * png_sizeof(png_uint_32)));
+ params_len = (png_size_tp)png_malloc(png_ptr,
+ (png_alloc_size_t)((png_alloc_size_t)nparams * (sizeof (size_t))));
/* Find the length of each parameter, making sure we don't count the
- null terminator for the last parameter. */
+ * null terminator for the last parameter.
+ */
for (i = 0; i < nparams; i++)
{
- params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
+ params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
png_debug2(3, "pCAL parameter %d length = %lu", i,
- (unsigned long) params_len[i]);
- total_len += (png_size_t)params_len[i];
+ (unsigned long)params_len[i]);
+ total_len += params_len[i];
}
png_debug1(3, "pCAL total length = %d", (int)total_len);
- png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
- png_write_chunk_data(png_ptr, (png_bytep)new_purpose,
- (png_size_t)purpose_len);
+ png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);
+ png_write_chunk_data(png_ptr, new_purpose, purpose_len);
png_save_int_32(buf, X0);
png_save_int_32(buf + 4, X1);
buf[8] = (png_byte)type;
buf[9] = (png_byte)nparams;
- png_write_chunk_data(png_ptr, buf, (png_size_t)10);
- png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);
-
- png_free(png_ptr, new_purpose);
+ png_write_chunk_data(png_ptr, buf, 10);
+ png_write_chunk_data(png_ptr, (png_const_bytep)units, (size_t)units_len);
for (i = 0; i < nparams; i++)
{
- png_write_chunk_data(png_ptr, (png_bytep)params[i],
- (png_size_t)params_len[i]);
+ png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);
}
png_free(png_ptr, params_len);
#ifdef PNG_WRITE_sCAL_SUPPORTED
/* Write the sCAL chunk */
-#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
-void /* PRIVATE */
-png_write_sCAL(png_structp png_ptr, int unit, double width, double height)
-{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_sCAL;
-#endif
- char buf[64];
- png_size_t total_len;
-
- png_debug(1, "in png_write_sCAL");
-
- buf[0] = (char)unit;
-#ifdef _WIN32_WCE
-/* sprintf() function is not supported on WindowsCE */
- {
- wchar_t wc_buf[32];
- size_t wc_len;
- swprintf(wc_buf, TEXT("%12.12e"), width);
- wc_len = wcslen(wc_buf);
- WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, buf + 1, wc_len, NULL,
- NULL);
- total_len = wc_len + 2;
- swprintf(wc_buf, TEXT("%12.12e"), height);
- wc_len = wcslen(wc_buf);
- WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, buf + total_len, wc_len,
- NULL, NULL);
- total_len += wc_len;
- }
-#else
- png_snprintf(buf + 1, 63, "%12.12e", width);
- total_len = 1 + png_strlen(buf + 1) + 1;
- png_snprintf(buf + total_len, 64-total_len, "%12.12e", height);
- total_len += png_strlen(buf + total_len);
-#endif
-
- png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
- png_write_chunk(png_ptr, (png_bytep)png_sCAL, (png_bytep)buf, total_len);
-}
-#else
-#ifdef PNG_FIXED_POINT_SUPPORTED
void /* PRIVATE */
-png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
- png_charp height)
+png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
+ png_const_charp height)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_sCAL;
-#endif
png_byte buf[64];
- png_size_t wlen, hlen, total_len;
+ size_t wlen, hlen, total_len;
png_debug(1, "in png_write_sCAL_s");
- wlen = png_strlen(width);
- hlen = png_strlen(height);
+ wlen = strlen(width);
+ hlen = strlen(height);
total_len = wlen + hlen + 2;
+
if (total_len > 64)
{
png_warning(png_ptr, "Can't write sCAL (buffer too small)");
}
buf[0] = (png_byte)unit;
- png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
- png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
+ memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
+ memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
- png_write_chunk(png_ptr, (png_bytep)png_sCAL, buf, total_len);
+ png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
}
#endif
-#endif
-#endif
#ifdef PNG_WRITE_pHYs_SUPPORTED
/* Write the pHYs chunk */
void /* PRIVATE */
-png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
- png_uint_32 y_pixels_per_unit,
- int unit_type)
+png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit,
+ png_uint_32 y_pixels_per_unit,
+ int unit_type)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_pHYs;
-#endif
png_byte buf[9];
png_debug(1, "in png_write_pHYs");
png_save_uint_32(buf + 4, y_pixels_per_unit);
buf[8] = (png_byte)unit_type;
- png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
+ png_write_complete_chunk(png_ptr, png_pHYs, buf, 9);
}
#endif
* or png_convert_from_time_t(), or fill in the structure yourself.
*/
void /* PRIVATE */
-png_write_tIME(png_structp png_ptr, png_timep mod_time)
+png_write_tIME(png_structrp png_ptr, png_const_timep mod_time)
{
-#ifdef PNG_USE_LOCAL_ARRAYS
- PNG_tIME;
-#endif
png_byte buf[7];
png_debug(1, "in png_write_tIME");
buf[5] = mod_time->minute;
buf[6] = mod_time->second;
- png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
+ png_write_complete_chunk(png_ptr, png_tIME, buf, 7);
}
#endif
/* Initializes the row writing capability of libpng */
void /* PRIVATE */
-png_write_start_row(png_structp png_ptr)
+png_write_start_row(png_structrp png_ptr)
{
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
/* Start of interlace block */
- int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+ static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
/* Offset to next interlace block */
- int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+ static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
/* Start of interlace block in the y direction */
- int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+ static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
/* Offset to next interlace block in the y direction */
- int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+ static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
#endif
- png_size_t buf_size;
+ png_alloc_size_t buf_size;
+ int usr_pixel_depth;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+ png_byte filters;
+#endif
png_debug(1, "in png_write_start_row");
- buf_size = (png_size_t)(PNG_ROWBYTES(
- png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1);
+ usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;
+ buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
+
+ /* 1.5.6: added to allow checking in the row write code. */
+ png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;
+ png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;
/* Set up row buffer */
- png_ptr->row_buf = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)buf_size);
+ png_ptr->row_buf = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
+
png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
#ifdef PNG_WRITE_FILTER_SUPPORTED
- /* Set up filtering buffer, if using this filter */
- if (png_ptr->do_filter & PNG_FILTER_SUB)
- {
- png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(png_ptr->rowbytes + 1));
- png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
- }
+ filters = png_ptr->do_filter;
+
+ if (png_ptr->height == 1)
+ filters &= 0xff & ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+ if (png_ptr->width == 1)
+ filters &= 0xff & ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+ if (filters == 0)
+ filters = PNG_FILTER_NONE;
- /* We only need to keep the previous row if we are using one of these. */
- if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
+ png_ptr->do_filter = filters;
+
+ if (((filters & (PNG_FILTER_SUB | PNG_FILTER_UP | PNG_FILTER_AVG |
+ PNG_FILTER_PAETH)) != 0) && png_ptr->try_row == NULL)
{
- /* Set up previous row buffer */
- png_ptr->prev_row = (png_bytep)png_calloc(png_ptr,
- (png_uint_32)buf_size);
+ int num_filters = 0;
- if (png_ptr->do_filter & PNG_FILTER_UP)
- {
- png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(png_ptr->rowbytes + 1));
- png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
- }
+ png_ptr->try_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
- if (png_ptr->do_filter & PNG_FILTER_AVG)
- {
- png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(png_ptr->rowbytes + 1));
- png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
- }
+ if (filters & PNG_FILTER_SUB)
+ num_filters++;
- if (png_ptr->do_filter & PNG_FILTER_PAETH)
- {
- png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(png_ptr->rowbytes + 1));
- png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
- }
+ if (filters & PNG_FILTER_UP)
+ num_filters++;
+
+ if (filters & PNG_FILTER_AVG)
+ num_filters++;
+
+ if (filters & PNG_FILTER_PAETH)
+ num_filters++;
+
+ if (num_filters > 1)
+ png_ptr->tst_row = png_voidcast(png_bytep, png_malloc(png_ptr,
+ buf_size));
}
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
+
+ /* We only need to keep the previous row if we are using one of the following
+ * filters.
+ */
+ if ((filters & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) != 0)
+ png_ptr->prev_row = png_voidcast(png_bytep,
+ png_calloc(png_ptr, buf_size));
+#endif /* WRITE_FILTER */
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
/* If interlaced, we need to set up width and height of pass */
- if (png_ptr->interlaced)
+ if (png_ptr->interlaced != 0)
{
- if (!(png_ptr->transformations & PNG_INTERLACE))
+ if ((png_ptr->transformations & PNG_INTERLACE) == 0)
{
png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
- png_pass_ystart[0]) / png_pass_yinc[0];
+ png_pass_ystart[0]) / png_pass_yinc[0];
+
png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
- png_pass_start[0]) / png_pass_inc[0];
+ png_pass_start[0]) / png_pass_inc[0];
}
+
else
{
png_ptr->num_rows = png_ptr->height;
png_ptr->usr_width = png_ptr->width;
}
}
+
else
#endif
{
png_ptr->num_rows = png_ptr->height;
png_ptr->usr_width = png_ptr->width;
}
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- png_ptr->zstream.next_out = png_ptr->zbuf;
}
/* Internal use only. Called when finished processing a row of data. */
void /* PRIVATE */
-png_write_finish_row(png_structp png_ptr)
+png_write_finish_row(png_structrp png_ptr)
{
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
/* Start of interlace block */
- int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+ static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
/* Offset to next interlace block */
- int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+ static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
/* Start of interlace block in the y direction */
- int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+ static const png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
/* Offset to next interlace block in the y direction */
- int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+ static const png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
#endif
- int ret;
-
png_debug(1, "in png_write_finish_row");
/* Next row */
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
/* If interlaced, go to next pass */
- if (png_ptr->interlaced)
+ if (png_ptr->interlaced != 0)
{
png_ptr->row_number = 0;
- if (png_ptr->transformations & PNG_INTERLACE)
+ if ((png_ptr->transformations & PNG_INTERLACE) != 0)
{
png_ptr->pass++;
}
+
else
{
/* Loop until we find a non-zero width or height pass */
do
{
png_ptr->pass++;
+
if (png_ptr->pass >= 7)
break;
+
png_ptr->usr_width = (png_ptr->width +
- png_pass_inc[png_ptr->pass] - 1 -
- png_pass_start[png_ptr->pass]) /
- png_pass_inc[png_ptr->pass];
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
png_ptr->num_rows = (png_ptr->height +
- png_pass_yinc[png_ptr->pass] - 1 -
- png_pass_ystart[png_ptr->pass]) /
- png_pass_yinc[png_ptr->pass];
- if (png_ptr->transformations & PNG_INTERLACE)
+ png_pass_yinc[png_ptr->pass] - 1 -
+ png_pass_ystart[png_ptr->pass]) /
+ png_pass_yinc[png_ptr->pass];
+
+ if ((png_ptr->transformations & PNG_INTERLACE) != 0)
break;
+
} while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
}
if (png_ptr->pass < 7)
{
if (png_ptr->prev_row != NULL)
- png_memset(png_ptr->prev_row, 0,
- (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
- png_ptr->usr_bit_depth, png_ptr->width)) + 1);
+ memset(png_ptr->prev_row, 0,
+ PNG_ROWBYTES(png_ptr->usr_channels *
+ png_ptr->usr_bit_depth, png_ptr->width) + 1);
+
return;
}
}
/* If we get here, we've just written the last row, so we need
to flush the compressor */
- do
- {
- /* Tell the compressor we are done */
- ret = deflate(&png_ptr->zstream, Z_FINISH);
- /* Check for an error */
- if (ret == Z_OK)
- {
- /* Check to see if we need more room */
- if (!(png_ptr->zstream.avail_out))
- {
- png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
- png_ptr->zstream.next_out = png_ptr->zbuf;
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- }
- }
- else if (ret != Z_STREAM_END)
- {
- if (png_ptr->zstream.msg != NULL)
- png_error(png_ptr, png_ptr->zstream.msg);
- else
- png_error(png_ptr, "zlib error");
- }
- } while (ret != Z_STREAM_END);
-
- /* Write any extra space */
- if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
- {
- png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
- png_ptr->zstream.avail_out);
- }
-
- deflateReset(&png_ptr->zstream);
- png_ptr->zstream.data_type = Z_BINARY;
+ png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH);
}
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
/* Start of interlace block */
- int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+ static const png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
/* Offset to next interlace block */
- int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+ static const png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
png_debug(1, "in png_do_write_interlace");
/* We don't have to do anything on the last pass (6) */
-#ifdef PNG_USELESS_TESTS_SUPPORTED
- if (row != NULL && row_info != NULL && pass < 6)
-#else
if (pass < 6)
-#endif
{
/* Each pixel depth is handled separately */
switch (row_info->pixel_depth)
{
png_bytep sp;
png_bytep dp;
- int shift;
+ unsigned int shift;
int d;
int value;
png_uint_32 i;
dp = row;
d = 0;
shift = 7;
+
for (i = png_pass_start[pass]; i < row_width;
i += png_pass_inc[pass])
{
- sp = row + (png_size_t)(i >> 3);
+ sp = row + (size_t)(i >> 3);
value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
d |= (value << shift);
*dp++ = (png_byte)d;
d = 0;
}
+
else
shift--;
}
if (shift != 7)
*dp = (png_byte)d;
+
break;
}
+
case 2:
{
png_bytep sp;
png_bytep dp;
- int shift;
+ unsigned int shift;
int d;
int value;
png_uint_32 i;
dp = row;
shift = 6;
d = 0;
+
for (i = png_pass_start[pass]; i < row_width;
i += png_pass_inc[pass])
{
- sp = row + (png_size_t)(i >> 2);
+ sp = row + (size_t)(i >> 2);
value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
d |= (value << shift);
*dp++ = (png_byte)d;
d = 0;
}
+
else
shift -= 2;
}
if (shift != 6)
- *dp = (png_byte)d;
+ *dp = (png_byte)d;
+
break;
}
+
case 4:
{
png_bytep sp;
png_bytep dp;
- int shift;
+ unsigned int shift;
int d;
int value;
png_uint_32 i;
shift = 4;
d = 0;
for (i = png_pass_start[pass]; i < row_width;
- i += png_pass_inc[pass])
+ i += png_pass_inc[pass])
{
- sp = row + (png_size_t)(i >> 1);
+ sp = row + (size_t)(i >> 1);
value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
d |= (value << shift);
*dp++ = (png_byte)d;
d = 0;
}
+
else
shift -= 4;
}
if (shift != 4)
*dp = (png_byte)d;
+
break;
}
+
default:
{
png_bytep sp;
png_bytep dp;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
- png_size_t pixel_bytes;
+ size_t pixel_bytes;
/* Start at the beginning */
dp = row;
+
/* Find out how many bytes each pixel takes up */
pixel_bytes = (row_info->pixel_depth >> 3);
- /* Loop through the row, only looking at the pixels that
- matter */
+
+ /* Loop through the row, only looking at the pixels that matter */
for (i = png_pass_start[pass]; i < row_width;
i += png_pass_inc[pass])
{
/* Find out where the original pixel is */
- sp = row + (png_size_t)i * pixel_bytes;
+ sp = row + (size_t)i * pixel_bytes;
+
/* Move the pixel */
if (dp != sp)
- png_memcpy(dp, sp, pixel_bytes);
+ memcpy(dp, sp, pixel_bytes);
+
/* Next pixel */
dp += pixel_bytes;
}
}
/* Set new row width */
row_info->width = (row_info->width +
- png_pass_inc[pass] - 1 -
- png_pass_start[pass]) /
- png_pass_inc[pass];
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
- row_info->width);
+ png_pass_inc[pass] - 1 -
+ png_pass_start[pass]) /
+ png_pass_inc[pass];
+
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_info->width);
}
}
#endif
+
/* This filters the row, chooses which filter to use, if it has not already
* been specified by the application, and then writes the row out with the
* chosen filter.
*/
-#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
-#define PNG_HISHIFT 10
-#define PNG_LOMASK ((png_uint_32)0xffffL)
-#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
-void /* PRIVATE */
-png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
-{
- png_bytep best_row;
-#ifdef PNG_WRITE_FILTER_SUPPORTED
- png_bytep prev_row, row_buf;
- png_uint_32 mins, bpp;
- png_byte filter_to_do = png_ptr->do_filter;
- png_uint_32 row_bytes = row_info->rowbytes;
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- int num_p_filters = (int)png_ptr->num_prev_filters;
-#endif
-
- png_debug(1, "in png_write_find_filter");
-
-#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
- {
- /* These will never be selected so we need not test them. */
- filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
- }
-#endif
-
- /* Find out how many bytes offset each pixel is */
- bpp = (row_info->pixel_depth + 7) >> 3;
+static void /* PRIVATE */
+png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
+ size_t row_bytes);
- prev_row = png_ptr->prev_row;
-#endif
- best_row = png_ptr->row_buf;
#ifdef PNG_WRITE_FILTER_SUPPORTED
- row_buf = best_row;
- mins = PNG_MAXSUM;
-
- /* The prediction method we use is to find which method provides the
- * smallest value when summing the absolute values of the distances
- * from zero, using anything >= 128 as negative numbers. This is known
- * as the "minimum sum of absolute differences" heuristic. Other
- * heuristics are the "weighted minimum sum of absolute differences"
- * (experimental and can in theory improve compression), and the "zlib
- * predictive" method (not implemented yet), which does test compressions
- * of lines using different filter methods, and then chooses the
- * (series of) filter(s) that give minimum compressed data size (VERY
- * computationally expensive).
- *
- * GRR 980525: consider also
- * (1) minimum sum of absolute differences from running average (i.e.,
- * keep running sum of non-absolute differences & count of bytes)
- * [track dispersion, too? restart average if dispersion too large?]
- * (1b) minimum sum of absolute differences from sliding average, probably
- * with window size <= deflate window (usually 32K)
- * (2) minimum sum of squared differences from zero or running average
- * (i.e., ~ root-mean-square approach)
- */
+static size_t /* PRIVATE */
+png_setup_sub_row(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes, size_t lmins)
+{
+ png_bytep rp, dp, lp;
+ size_t i;
+ size_t sum = 0;
+ unsigned int v;
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
- /* We don't need to test the 'no filter' case if this is the only filter
- * that has been chosen, as it doesn't actually do anything to the data.
- */
- if ((filter_to_do & PNG_FILTER_NONE) &&
- filter_to_do != PNG_FILTER_NONE)
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp;
+ i++, rp++, dp++)
{
- png_bytep rp;
- png_uint_32 sum = 0;
- png_uint_32 i;
- int v;
+ v = *dp = *rp;
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
+ }
- for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
- {
- v = *rp;
- sum += (v < 128) ? v : 256 - v;
- }
+ for (lp = png_ptr->row_buf + 1; i < row_bytes;
+ i++, rp++, lp++, dp++)
+ {
+ v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- png_uint_32 sumhi, sumlo;
- int j;
- sumlo = sum & PNG_LOMASK;
- sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
- /* Reduce the sum if we match any of the previous rows */
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
- {
- sumlo = (sumlo * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- sumhi = (sumhi * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
+ return (sum);
+}
- /* Factor in the cost of this filter (this is here for completeness,
- * but it makes no sense to have a "cost" for the NONE filter, as
- * it has the minimum possible computational cost - none).
- */
- sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
- PNG_COST_SHIFT;
- sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
- PNG_COST_SHIFT;
+static void /* PRIVATE */
+png_setup_sub_row_only(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes)
+{
+ png_bytep rp, dp, lp;
+ size_t i;
- if (sumhi > PNG_HIMASK)
- sum = PNG_MAXSUM;
- else
- sum = (sumhi << PNG_HISHIFT) + sumlo;
- }
-#endif
- mins = sum;
- }
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
- /* Sub filter */
- if (filter_to_do == PNG_FILTER_SUB)
- /* It's the only filter so no testing is needed */
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp;
+ i++, rp++, dp++)
{
- png_bytep rp, lp, dp;
- png_uint_32 i;
- for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
- i++, rp++, dp++)
- {
- *dp = *rp;
- }
- for (lp = row_buf + 1; i < row_bytes;
- i++, rp++, lp++, dp++)
- {
- *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
- }
- best_row = png_ptr->sub_row;
+ *dp = *rp;
}
- else if (filter_to_do & PNG_FILTER_SUB)
+ for (lp = png_ptr->row_buf + 1; i < row_bytes;
+ i++, rp++, lp++, dp++)
{
- png_bytep rp, dp, lp;
- png_uint_32 sum = 0, lmins = mins;
- png_uint_32 i;
- int v;
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- /* We temporarily increase the "minimum sum" by the factor we
- * would reduce the sum of this filter, so that we can do the
- * early exit comparison without scaling the sum each time.
- */
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 lmhi, lmlo;
- lmlo = lmins & PNG_LOMASK;
- lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+ *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+ }
+}
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
- {
- lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
+static size_t /* PRIVATE */
+png_setup_up_row(png_structrp png_ptr, size_t row_bytes, size_t lmins)
+{
+ png_bytep rp, dp, pp;
+ size_t i;
+ size_t sum = 0;
+ unsigned int v;
- lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
- PNG_COST_SHIFT;
- lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
- PNG_COST_SHIFT;
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
- if (lmhi > PNG_HIMASK)
- lmins = PNG_MAXSUM;
- else
- lmins = (lmhi << PNG_HISHIFT) + lmlo;
- }
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < row_bytes;
+ i++, rp++, pp++, dp++)
+ {
+ v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
#endif
- for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
- i++, rp++, dp++)
- {
- v = *dp = *rp;
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
+ }
- sum += (v < 128) ? v : 256 - v;
- }
- for (lp = row_buf + 1; i < row_bytes;
- i++, rp++, lp++, dp++)
- {
- v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+ return (sum);
+}
+static void /* PRIVATE */
+png_setup_up_row_only(png_structrp png_ptr, size_t row_bytes)
+{
+ png_bytep rp, dp, pp;
+ size_t i;
- sum += (v < 128) ? v : 256 - v;
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
- if (sum > lmins) /* We are already worse, don't continue. */
- break;
- }
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < row_bytes;
+ i++, rp++, pp++, dp++)
+ {
+ *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
+ }
+}
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 sumhi, sumlo;
- sumlo = sum & PNG_LOMASK;
- sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+static size_t /* PRIVATE */
+png_setup_avg_row(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes, size_t lmins)
+{
+ png_bytep rp, dp, pp, lp;
+ png_uint_32 i;
+ size_t sum = 0;
+ unsigned int v;
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
- {
- sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
- sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
- PNG_COST_SHIFT;
- sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
- PNG_COST_SHIFT;
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < bpp; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
- if (sumhi > PNG_HIMASK)
- sum = PNG_MAXSUM;
- else
- sum = (sumhi << PNG_HISHIFT) + sumlo;
- }
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
#endif
-
- if (sum < mins)
- {
- mins = sum;
- best_row = png_ptr->sub_row;
- }
}
- /* Up filter */
- if (filter_to_do == PNG_FILTER_UP)
+ for (lp = png_ptr->row_buf + 1; i < row_bytes; i++)
{
- png_bytep rp, dp, pp;
- png_uint_32 i;
+ v = *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
+ & 0xff);
- for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
- pp = prev_row + 1; i < row_bytes;
- i++, rp++, pp++, dp++)
- {
- *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
- }
- best_row = png_ptr->up_row;
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
+#endif
+
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
}
- else if (filter_to_do & PNG_FILTER_UP)
+ return (sum);
+}
+static void /* PRIVATE */
+png_setup_avg_row_only(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes)
+{
+ png_bytep rp, dp, pp, lp;
+ png_uint_32 i;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < bpp; i++)
{
- png_bytep rp, dp, pp;
- png_uint_32 sum = 0, lmins = mins;
- png_uint_32 i;
- int v;
+ *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+ }
+ for (lp = png_ptr->row_buf + 1; i < row_bytes; i++)
+ {
+ *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
+ & 0xff);
+ }
+}
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 lmhi, lmlo;
- lmlo = lmins & PNG_LOMASK;
- lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+static size_t /* PRIVATE */
+png_setup_paeth_row(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes, size_t lmins)
+{
+ png_bytep rp, dp, pp, cp, lp;
+ size_t i;
+ size_t sum = 0;
+ unsigned int v;
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
- {
- lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
- lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
- PNG_COST_SHIFT;
- lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
- PNG_COST_SHIFT;
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < bpp; i++)
+ {
+ v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
- if (lmhi > PNG_HIMASK)
- lmins = PNG_MAXSUM;
- else
- lmins = (lmhi << PNG_HISHIFT) + lmlo;
- }
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
#endif
+ }
- for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
- pp = prev_row + 1; i < row_bytes; i++)
- {
- v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+ for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes;
+ i++)
+ {
+ int a, b, c, pa, pb, pc, p;
- sum += (v < 128) ? v : 256 - v;
+ b = *pp++;
+ c = *cp++;
+ a = *lp++;
- if (sum > lmins) /* We are already worse, don't continue. */
- break;
- }
+ p = b - c;
+ pc = a - c;
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 sumhi, sumlo;
- sumlo = sum & PNG_LOMASK;
- sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
- {
- sumlo = (sumlo * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- sumhi = (sumhi * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
+ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
- sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
- PNG_COST_SHIFT;
- sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
- PNG_COST_SHIFT;
+ v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
- if (sumhi > PNG_HIMASK)
- sum = PNG_MAXSUM;
- else
- sum = (sumhi << PNG_HISHIFT) + sumlo;
- }
+#ifdef PNG_USE_ABS
+ sum += 128 - abs((int)v - 128);
+#else
+ sum += (v < 128) ? v : 256 - v;
#endif
- if (sum < mins)
- {
- mins = sum;
- best_row = png_ptr->up_row;
- }
+ if (sum > lmins) /* We are already worse, don't continue. */
+ break;
}
- /* Avg filter */
- if (filter_to_do == PNG_FILTER_AVG)
+ return (sum);
+}
+static void /* PRIVATE */
+png_setup_paeth_row_only(png_structrp png_ptr, png_uint_32 bpp,
+ size_t row_bytes)
+{
+ png_bytep rp, dp, pp, cp, lp;
+ size_t i;
+
+ png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
+
+ for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+ pp = png_ptr->prev_row + 1; i < bpp; i++)
{
- png_bytep rp, dp, pp, lp;
- png_uint_32 i;
- for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
- pp = prev_row + 1; i < bpp; i++)
- {
- *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
- }
- for (lp = row_buf + 1; i < row_bytes; i++)
- {
- *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
- & 0xff);
- }
- best_row = png_ptr->avg_row;
+ *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
}
- else if (filter_to_do & PNG_FILTER_AVG)
+ for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes;
+ i++)
{
- png_bytep rp, dp, pp, lp;
- png_uint_32 sum = 0, lmins = mins;
- png_uint_32 i;
- int v;
+ int a, b, c, pa, pb, pc, p;
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 lmhi, lmlo;
- lmlo = lmins & PNG_LOMASK;
- lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+ b = *pp++;
+ c = *cp++;
+ a = *lp++;
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
- {
- lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
+ p = b - c;
+ pc = a - c;
- lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
- PNG_COST_SHIFT;
- lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
- PNG_COST_SHIFT;
-
- if (lmhi > PNG_HIMASK)
- lmins = PNG_MAXSUM;
- else
- lmins = (lmhi << PNG_HISHIFT) + lmlo;
- }
+#ifdef PNG_USE_ABS
+ pa = abs(p);
+ pb = abs(pc);
+ pc = abs(p + pc);
+#else
+ pa = p < 0 ? -p : p;
+ pb = pc < 0 ? -pc : pc;
+ pc = (p + pc) < 0 ? -(p + pc) : p + pc;
#endif
- for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
- pp = prev_row + 1; i < bpp; i++)
- {
- v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
- sum += (v < 128) ? v : 256 - v;
- }
- for (lp = row_buf + 1; i < row_bytes; i++)
- {
- v = *dp++ =
- (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
+ *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+ }
+}
+#endif /* WRITE_FILTER */
- sum += (v < 128) ? v : 256 - v;
+void /* PRIVATE */
+png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
+{
+#ifndef PNG_WRITE_FILTER_SUPPORTED
+ png_write_filtered_row(png_ptr, png_ptr->row_buf, row_info->rowbytes+1);
+#else
+ unsigned int filter_to_do = png_ptr->do_filter;
+ png_bytep row_buf;
+ png_bytep best_row;
+ png_uint_32 bpp;
+ size_t mins;
+ size_t row_bytes = row_info->rowbytes;
- if (sum > lmins) /* We are already worse, don't continue. */
- break;
- }
+ png_debug(1, "in png_write_find_filter");
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 sumhi, sumlo;
- sumlo = sum & PNG_LOMASK;
- sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
+ /* Find out how many bytes offset each pixel is */
+ bpp = (row_info->pixel_depth + 7) >> 3;
- for (j = 0; j < num_p_filters; j++)
- {
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
- {
- sumlo = (sumlo * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- sumhi = (sumhi * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
- }
+ row_buf = png_ptr->row_buf;
+ mins = PNG_SIZE_MAX - 256/* so we can detect potential overflow of the
+ running sum */;
+
+ /* The prediction method we use is to find which method provides the
+ * smallest value when summing the absolute values of the distances
+ * from zero, using anything >= 128 as negative numbers. This is known
+ * as the "minimum sum of absolute differences" heuristic. Other
+ * heuristics are the "weighted minimum sum of absolute differences"
+ * (experimental and can in theory improve compression), and the "zlib
+ * predictive" method (not implemented yet), which does test compressions
+ * of lines using different filter methods, and then chooses the
+ * (series of) filter(s) that give minimum compressed data size (VERY
+ * computationally expensive).
+ *
+ * GRR 980525: consider also
+ *
+ * (1) minimum sum of absolute differences from running average (i.e.,
+ * keep running sum of non-absolute differences & count of bytes)
+ * [track dispersion, too? restart average if dispersion too large?]
+ *
+ * (1b) minimum sum of absolute differences from sliding average, probably
+ * with window size <= deflate window (usually 32K)
+ *
+ * (2) minimum sum of squared differences from zero or running average
+ * (i.e., ~ root-mean-square approach)
+ */
- sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
- PNG_COST_SHIFT;
- sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
- PNG_COST_SHIFT;
- if (sumhi > PNG_HIMASK)
- sum = PNG_MAXSUM;
- else
- sum = (sumhi << PNG_HISHIFT) + sumlo;
- }
-#endif
+ /* We don't need to test the 'no filter' case if this is the only filter
+ * that has been chosen, as it doesn't actually do anything to the data.
+ */
+ best_row = png_ptr->row_buf;
- if (sum < mins)
- {
- mins = sum;
- best_row = png_ptr->avg_row;
- }
+ if (PNG_SIZE_MAX/128 <= row_bytes)
+ {
+ /* Overflow can occur in the calculation, just select the lowest set
+ * filter.
+ */
+ filter_to_do &= 0U-filter_to_do;
}
-
- /* Paeth filter */
- if (filter_to_do == PNG_FILTER_PAETH)
+ else if ((filter_to_do & PNG_FILTER_NONE) != 0 &&
+ filter_to_do != PNG_FILTER_NONE)
{
- png_bytep rp, dp, pp, cp, lp;
- png_uint_32 i;
- for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
- pp = prev_row + 1; i < bpp; i++)
- {
- *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
- }
+ /* Overflow not possible and multiple filters in the list, including the
+ * 'none' filter.
+ */
+ png_bytep rp;
+ size_t sum = 0;
+ size_t i;
+ unsigned int v;
- for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
{
- int a, b, c, pa, pb, pc, p;
-
- b = *pp++;
- c = *cp++;
- a = *lp++;
-
- p = b - c;
- pc = a - c;
-
+ for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
+ {
+ v = *rp;
#ifdef PNG_USE_ABS
- pa = abs(p);
- pb = abs(pc);
- pc = abs(p + pc);
+ sum += 128 - abs((int)v - 128);
#else
- pa = p < 0 ? -p : p;
- pb = pc < 0 ? -pc : pc;
- pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+ sum += (v < 128) ? v : 256 - v;
#endif
+ }
+ }
- p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+ mins = sum;
+ }
- *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
- }
- best_row = png_ptr->paeth_row;
+ /* Sub filter */
+ if (filter_to_do == PNG_FILTER_SUB)
+ /* It's the only filter so no testing is needed */
+ {
+ png_setup_sub_row_only(png_ptr, bpp, row_bytes);
+ best_row = png_ptr->try_row;
}
- else if (filter_to_do & PNG_FILTER_PAETH)
+ else if ((filter_to_do & PNG_FILTER_SUB) != 0)
{
- png_bytep rp, dp, pp, cp, lp;
- png_uint_32 sum = 0, lmins = mins;
- png_uint_32 i;
- int v;
+ size_t sum;
+ size_t lmins = mins;
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
- {
- int j;
- png_uint_32 lmhi, lmlo;
- lmlo = lmins & PNG_LOMASK;
- lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
+ sum = png_setup_sub_row(png_ptr, bpp, row_bytes, lmins);
- for (j = 0; j < num_p_filters; j++)
+ if (sum < mins)
+ {
+ mins = sum;
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
{
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
- {
- lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
}
-
- lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
- PNG_COST_SHIFT;
- lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
- PNG_COST_SHIFT;
-
- if (lmhi > PNG_HIMASK)
- lmins = PNG_MAXSUM;
- else
- lmins = (lmhi << PNG_HISHIFT) + lmlo;
- }
-#endif
-
- for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
- pp = prev_row + 1; i < bpp; i++)
- {
- v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
-
- sum += (v < 128) ? v : 256 - v;
}
+ }
- for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
- {
- int a, b, c, pa, pb, pc, p;
-
- b = *pp++;
- c = *cp++;
- a = *lp++;
-
-#ifndef PNG_SLOW_PAETH
- p = b - c;
- pc = a - c;
-#ifdef PNG_USE_ABS
- pa = abs(p);
- pb = abs(pc);
- pc = abs(p + pc);
-#else
- pa = p < 0 ? -p : p;
- pb = pc < 0 ? -pc : pc;
- pc = (p + pc) < 0 ? -(p + pc) : p + pc;
-#endif
- p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
-#else /* PNG_SLOW_PAETH */
- p = a + b - c;
- pa = abs(p - a);
- pb = abs(p - b);
- pc = abs(p - c);
- if (pa <= pb && pa <= pc)
- p = a;
- else if (pb <= pc)
- p = b;
- else
- p = c;
-#endif /* PNG_SLOW_PAETH */
-
- v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+ /* Up filter */
+ if (filter_to_do == PNG_FILTER_UP)
+ {
+ png_setup_up_row_only(png_ptr, row_bytes);
+ best_row = png_ptr->try_row;
+ }
- sum += (v < 128) ? v : 256 - v;
+ else if ((filter_to_do & PNG_FILTER_UP) != 0)
+ {
+ size_t sum;
+ size_t lmins = mins;
- if (sum > lmins) /* We are already worse, don't continue. */
- break;
- }
+ sum = png_setup_up_row(png_ptr, row_bytes, lmins);
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
+ if (sum < mins)
{
- int j;
- png_uint_32 sumhi, sumlo;
- sumlo = sum & PNG_LOMASK;
- sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
- for (j = 0; j < num_p_filters; j++)
+ mins = sum;
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
{
- if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
- {
- sumlo = (sumlo * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- sumhi = (sumhi * png_ptr->filter_weights[j]) >>
- PNG_WEIGHT_SHIFT;
- }
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
}
+ }
+ }
+
+ /* Avg filter */
+ if (filter_to_do == PNG_FILTER_AVG)
+ {
+ png_setup_avg_row_only(png_ptr, bpp, row_bytes);
+ best_row = png_ptr->try_row;
+ }
- sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
- PNG_COST_SHIFT;
- sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
- PNG_COST_SHIFT;
+ else if ((filter_to_do & PNG_FILTER_AVG) != 0)
+ {
+ size_t sum;
+ size_t lmins = mins;
- if (sumhi > PNG_HIMASK)
- sum = PNG_MAXSUM;
- else
- sum = (sumhi << PNG_HISHIFT) + sumlo;
- }
-#endif
+ sum= png_setup_avg_row(png_ptr, bpp, row_bytes, lmins);
if (sum < mins)
{
- best_row = png_ptr->paeth_row;
+ mins = sum;
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
+ {
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
+ }
}
}
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
- /* Do the actual writing of the filtered row data from the chosen filter. */
- png_write_filtered_row(png_ptr, best_row);
+ /* Paeth filter */
+ if (filter_to_do == PNG_FILTER_PAETH)
+ {
+ png_setup_paeth_row_only(png_ptr, bpp, row_bytes);
+ best_row = png_ptr->try_row;
+ }
-#ifdef PNG_WRITE_FILTER_SUPPORTED
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
- /* Save the type of filter we picked this time for future calculations */
- if (png_ptr->num_prev_filters > 0)
+ else if ((filter_to_do & PNG_FILTER_PAETH) != 0)
{
- int j;
- for (j = 1; j < num_p_filters; j++)
+ size_t sum;
+ size_t lmins = mins;
+
+ sum = png_setup_paeth_row(png_ptr, bpp, row_bytes, lmins);
+
+ if (sum < mins)
{
- png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
+ best_row = png_ptr->try_row;
+ if (png_ptr->tst_row != NULL)
+ {
+ png_ptr->try_row = png_ptr->tst_row;
+ png_ptr->tst_row = best_row;
+ }
}
- png_ptr->prev_filters[j] = best_row[0];
}
-#endif
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
+
+ /* Do the actual writing of the filtered row data from the chosen filter. */
+ png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);
+
+#endif /* WRITE_FILTER */
}
/* Do the actual writing of a previously filtered row. */
-void /* PRIVATE */
-png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
+static void
+png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
+ size_t full_row_length/*includes filter byte*/)
{
png_debug(1, "in png_write_filtered_row");
png_debug1(2, "filter = %d", filtered_row[0]);
- /* Set up the zlib input buffer */
-
- png_ptr->zstream.next_in = filtered_row;
- png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
- /* Repeat until we have compressed all the data */
- do
- {
- int ret; /* Return of zlib */
-
- /* Compress the data */
- ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
- /* Check for compression errors */
- if (ret != Z_OK)
- {
- if (png_ptr->zstream.msg != NULL)
- png_error(png_ptr, png_ptr->zstream.msg);
- else
- png_error(png_ptr, "zlib error");
- }
- /* See if it is time to write another IDAT */
- if (!(png_ptr->zstream.avail_out))
- {
- /* Write the IDAT and reset the zlib output buffer */
- png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
- png_ptr->zstream.next_out = png_ptr->zbuf;
- png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
- }
- /* Repeat until all data has been compressed */
- } while (png_ptr->zstream.avail_in);
+ png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH);
+#ifdef PNG_WRITE_FILTER_SUPPORTED
/* Swap the current and previous rows */
if (png_ptr->prev_row != NULL)
{
png_ptr->prev_row = png_ptr->row_buf;
png_ptr->row_buf = tptr;
}
+#endif /* WRITE_FILTER */
/* Finish row - updates counters and flushes zlib if last row */
png_write_finish_row(png_ptr);
{
png_write_flush(png_ptr);
}
-#endif
+#endif /* WRITE_FLUSH */
}
-#endif /* PNG_WRITE_SUPPORTED */
+#endif /* WRITE */
projects / platform / upstream / libpng.git / blobdiff