Wei Chang Shen
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by 
Embedded Artists
Diff: png/pngrutil.c
- Revision:
- 2:0e2ef1edf01b
diff -r 2847cc35a84f -r 0e2ef1edf01b png/pngrutil.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/png/pngrutil.c Thu Jun 02 04:52:54 2016 +0000
@@ -0,0 +1,3127 @@
+
+/* pngrutil.c - utilities to read a PNG file
+ *
+ * Last changed in libpng 1.2.15 January 5, 2007
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2007 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.)
+ *
+ * This file contains routines that are only called from within
+ * libpng itself during the course of reading an image.
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+#if defined(PNG_READ_SUPPORTED)
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+# if defined(_WIN32_WCE)
+/* strtod() function is not supported on WindowsCE */
+__inline double png_strtod(png_structp png_ptr, const char *nptr, char **endptr)
+{
+ double result = 0;
+ int len;
+ wchar_t *str, *end;
+
+ len = MultiByteToWideChar(CP_ACP, 0, nptr, -1, NULL, 0);
+ str = (wchar_t *)png_malloc(png_ptr, len * sizeof(wchar_t));
+ if ( NULL != str )
+ {
+ MultiByteToWideChar(CP_ACP, 0, nptr, -1, str, len);
+ result = wcstod(str, &end);
+ len = WideCharToMultiByte(CP_ACP, 0, end, -1, NULL, 0, NULL, NULL);
+ *endptr = (char *)nptr + (png_strlen(nptr) - len + 1);
+ png_free(str);
+ }
+ return result;
+}
+# else
+# define png_strtod(p,a,b) strtod(a,b)
+# endif
+#endif
+
+png_uint_32 PNGAPI
+png_get_uint_31(png_structp png_ptr, png_bytep buf)
+{
+ png_uint_32 i = png_get_uint_32(buf);
+ if (i > PNG_UINT_31_MAX)
+ png_error(png_ptr, "PNG unsigned integer out of range.");
+ return (i);
+}
+#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
+/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
+png_uint_32 PNGAPI
+png_get_uint_32(png_bytep buf)
+{
+ png_uint_32 i = ((png_uint_32)(*buf) << 24) +
+ ((png_uint_32)(*(buf + 1)) << 16) +
+ ((png_uint_32)(*(buf + 2)) << 8) +
+ (png_uint_32)(*(buf + 3));
+
+ return (i);
+}
+
+/* Grab a signed 32-bit integer from a buffer in big-endian format. The
+ * data is stored in the PNG file in two's complement format, and it is
+ * assumed that the machine format for signed integers is the same. */
+png_int_32 PNGAPI
+png_get_int_32(png_bytep buf)
+{
+ png_int_32 i = ((png_int_32)(*buf) << 24) +
+ ((png_int_32)(*(buf + 1)) << 16) +
+ ((png_int_32)(*(buf + 2)) << 8) +
+ (png_int_32)(*(buf + 3));
+
+ return (i);
+}
+
+/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
+png_uint_16 PNGAPI
+png_get_uint_16(png_bytep buf)
+{
+ png_uint_16 i = (png_uint_16)(((png_uint_16)(*buf) << 8) +
+ (png_uint_16)(*(buf + 1)));
+
+ return (i);
+}
+#endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */
+
+/* Read data, and (optionally) run it through the CRC. */
+void /* PRIVATE */
+png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
+{
+ if(png_ptr == NULL) return;
+ png_read_data(png_ptr, buf, length);
+ png_calculate_crc(png_ptr, buf, length);
+}
+
+/* Optionally skip data and then check the CRC. Depending on whether we
+ are reading a ancillary or critical chunk, and how the program has set
+ things up, we may calculate the CRC on the data and print a message.
+ Returns '1' if there was a CRC error, '0' otherwise. */
+int /* PRIVATE */
+png_crc_finish(png_structp png_ptr, png_uint_32 skip)
+{
+ png_size_t i;
+ png_size_t istop = png_ptr->zbuf_size;
+
+ for (i = (png_size_t)skip; i > istop; i -= istop)
+ {
+ png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
+ }
+ if (i)
+ {
+ png_crc_read(png_ptr, png_ptr->zbuf, i);
+ }
+
+ if (png_crc_error(png_ptr))
+ {
+ if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */
+ !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) ||
+ (!(png_ptr->chunk_name[0] & 0x20) && /* Critical */
+ (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)))
+ {
+ png_chunk_warning(png_ptr, "CRC error");
+ }
+ else
+ {
+ png_chunk_error(png_ptr, "CRC error");
+ }
+ return (1);
+ }
+
+ return (0);
+}
+
+/* Compare the CRC stored in the PNG file with that calculated by libpng from
+ the data it has read thus far. */
+int /* PRIVATE */
+png_crc_error(png_structp png_ptr)
+{
+ png_byte crc_bytes[4];
+ png_uint_32 crc;
+ int need_crc = 1;
+
+ if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
+ {
+ if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+ (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+ need_crc = 0;
+ }
+ else /* critical */
+ {
+ if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
+ need_crc = 0;
+ }
+
+ png_read_data(png_ptr, crc_bytes, 4);
+
+ if (need_crc)
+ {
+ crc = png_get_uint_32(crc_bytes);
+ return ((int)(crc != png_ptr->crc));
+ }
+ else
+ return (0);
+}
+
+#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
+ defined(PNG_READ_iCCP_SUPPORTED)
+/*
+ * Decompress trailing data in a chunk. The assumption is that chunkdata
+ * points at an allocated area holding the contents of a chunk with a
+ * trailing compressed part. What we get back is an allocated area
+ * holding the original prefix part and an uncompressed version of the
+ * trailing part (the malloc area passed in is freed).
+ */
+png_charp /* PRIVATE */
+png_decompress_chunk(png_structp png_ptr, int comp_type,
+ png_charp chunkdata, png_size_t chunklength,
+ png_size_t prefix_size, png_size_t *newlength)
+{
+ static char msg[] = "Error decoding compressed text";
+ png_charp text;
+ png_size_t text_size;
+
+ if (comp_type == PNG_COMPRESSION_TYPE_BASE)
+ {
+ int ret = Z_OK;
+ png_ptr->zstream.next_in = (png_bytep)(chunkdata + prefix_size);
+ png_ptr->zstream.avail_in = (uInt)(chunklength - prefix_size);
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+
+ text_size = 0;
+ text = NULL;
+
+ while (png_ptr->zstream.avail_in)
+ {
+ ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+ if (ret != Z_OK && ret != Z_STREAM_END)
+ {
+ if (png_ptr->zstream.msg != NULL)
+ png_warning(png_ptr, png_ptr->zstream.msg);
+ else
+ png_warning(png_ptr, msg);
+ inflateReset(&png_ptr->zstream);
+ png_ptr->zstream.avail_in = 0;
+
+ if (text == NULL)
+ {
+ text_size = prefix_size + png_sizeof(msg) + 1;
+ text = (png_charp)png_malloc_warn(png_ptr, text_size);
+ if (text == NULL)
+ {
+ png_free(png_ptr,chunkdata);
+ png_error(png_ptr,"Not enough memory to decompress chunk");
+ }
+ png_memcpy(text, chunkdata, prefix_size);
+ }
+
+ text[text_size - 1] = 0x00;
+
+ /* Copy what we can of the error message into the text chunk */
+ text_size = (png_size_t)(chunklength - (text - chunkdata) - 1);
+ text_size = png_sizeof(msg) > text_size ? text_size :
+ png_sizeof(msg);
+ png_memcpy(text + prefix_size, msg, text_size + 1);
+ break;
+ }
+ if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END)
+ {
+ if (text == NULL)
+ {
+ text_size = prefix_size +
+ png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+ text = (png_charp)png_malloc_warn(png_ptr, text_size + 1);
+ if (text == NULL)
+ {
+ png_free(png_ptr,chunkdata);
+ png_error(png_ptr,"Not enough memory to decompress chunk.");
+ }
+ png_memcpy(text + prefix_size, png_ptr->zbuf,
+ text_size - prefix_size);
+ png_memcpy(text, chunkdata, prefix_size);
+ *(text + text_size) = 0x00;
+ }
+ else
+ {
+ png_charp tmp;
+
+ tmp = text;
+ text = (png_charp)png_malloc_warn(png_ptr,
+ (png_uint_32)(text_size +
+ png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1));
+ if (text == NULL)
+ {
+ png_free(png_ptr, tmp);
+ png_free(png_ptr, chunkdata);
+ png_error(png_ptr,"Not enough memory to decompress chunk..");
+ }
+ png_memcpy(text, tmp, text_size);
+ png_free(png_ptr, tmp);
+ png_memcpy(text + text_size, png_ptr->zbuf,
+ (png_ptr->zbuf_size - png_ptr->zstream.avail_out));
+ text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+ *(text + text_size) = 0x00;
+ }
+ if (ret == Z_STREAM_END)
+ break;
+ else
+ {
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ }
+ }
+ }
+ if (ret != Z_STREAM_END)
+ {
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+ char umsg[52];
+
+ if (ret == Z_BUF_ERROR)
+ sprintf(umsg,"Buffer error in compressed datastream in %s chunk",
+ png_ptr->chunk_name);
+ else if (ret == Z_DATA_ERROR)
+ sprintf(umsg,"Data error in compressed datastream in %s chunk",
+ png_ptr->chunk_name);
+ else
+ sprintf(umsg,"Incomplete compressed datastream in %s chunk",
+ png_ptr->chunk_name);
+ png_warning(png_ptr, umsg);
+#else
+ png_warning(png_ptr,
+ "Incomplete compressed datastream in chunk other than IDAT");
+#endif
+ text_size=prefix_size;
+ if (text == NULL)
+ {
+ text = (png_charp)png_malloc_warn(png_ptr, text_size+1);
+ if (text == NULL)
+ {
+ png_free(png_ptr, chunkdata);
+ png_error(png_ptr,"Not enough memory for text.");
+ }
+ png_memcpy(text, chunkdata, prefix_size);
+ }
+ *(text + text_size) = 0x00;
+ }
+
+ inflateReset(&png_ptr->zstream);
+ png_ptr->zstream.avail_in = 0;
+
+ png_free(png_ptr, chunkdata);
+ chunkdata = text;
+ *newlength=text_size;
+ }
+ else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
+ {
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+ char umsg[50];
+
+ sprintf(umsg, "Unknown zTXt compression type %d", comp_type);
+ png_warning(png_ptr, umsg);
+#else
+ png_warning(png_ptr, "Unknown zTXt compression type");
+#endif
+
+ *(chunkdata + prefix_size) = 0x00;
+ *newlength=prefix_size;
+ }
+
+ return chunkdata;
+}
+#endif
+
+/* read and check the IDHR chunk */
+void /* PRIVATE */
+png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[13];
+ png_uint_32 width, height;
+ int bit_depth, color_type, compression_type, filter_type;
+ int interlace_type;
+
+ png_debug(1, "in png_handle_IHDR\n");
+
+ if (png_ptr->mode & PNG_HAVE_IHDR)
+ png_error(png_ptr, "Out of place IHDR");
+
+ /* check the length */
+ if (length != 13)
+ png_error(png_ptr, "Invalid IHDR chunk");
+
+ png_ptr->mode |= PNG_HAVE_IHDR;
+
+ png_crc_read(png_ptr, buf, 13);
+ png_crc_finish(png_ptr, 0);
+
+ width = png_get_uint_31(png_ptr, buf);
+ height = png_get_uint_31(png_ptr, buf + 4);
+ bit_depth = buf[8];
+ color_type = buf[9];
+ compression_type = buf[10];
+ filter_type = buf[11];
+ interlace_type = buf[12];
+
+ /* set internal variables */
+ png_ptr->width = width;
+ png_ptr->height = height;
+ png_ptr->bit_depth = (png_byte)bit_depth;
+ png_ptr->interlaced = (png_byte)interlace_type;
+ png_ptr->color_type = (png_byte)color_type;
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+ png_ptr->filter_type = (png_byte)filter_type;
+#endif
+ png_ptr->compression_type = (png_byte)compression_type;
+
+ /* find number of channels */
+ switch (png_ptr->color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ case PNG_COLOR_TYPE_PALETTE:
+ png_ptr->channels = 1;
+ break;
+ case PNG_COLOR_TYPE_RGB:
+ png_ptr->channels = 3;
+ break;
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ png_ptr->channels = 2;
+ break;
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ png_ptr->channels = 4;
+ break;
+ }
+
+ /* set up other useful info */
+ png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
+ png_ptr->channels);
+ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->width);
+ png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth);
+ png_debug1(3,"channels = %d\n", png_ptr->channels);
+ png_debug1(3,"rowbytes = %lu\n", png_ptr->rowbytes);
+ png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
+ color_type, interlace_type, compression_type, filter_type);
+}
+
+/* read and check the palette */
+void /* PRIVATE */
+png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_color palette[PNG_MAX_PALETTE_LENGTH];
+ int num, i;
+#ifndef PNG_NO_POINTER_INDEXING
+ png_colorp pal_ptr;
+#endif
+
+ png_debug(1, "in png_handle_PLTE\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before PLTE");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid PLTE after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ png_error(png_ptr, "Duplicate PLTE chunk");
+
+ png_ptr->mode |= PNG_HAVE_PLTE;
+
+ if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
+ {
+ png_warning(png_ptr,
+ "Ignoring PLTE chunk in grayscale PNG");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
+ if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#endif
+
+ if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
+ {
+ if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ png_warning(png_ptr, "Invalid palette chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else
+ {
+ png_error(png_ptr, "Invalid palette chunk");
+ }
+ }
+
+ num = (int)length / 3;
+
+#ifndef PNG_NO_POINTER_INDEXING
+ for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
+ {
+ png_byte buf[3];
+
+ png_crc_read(png_ptr, buf, 3);
+ pal_ptr->red = buf[0];
+ pal_ptr->green = buf[1];
+ pal_ptr->blue = buf[2];
+ }
+#else
+ for (i = 0; i < num; i++)
+ {
+ png_byte buf[3];
+
+ png_crc_read(png_ptr, buf, 3);
+ /* don't depend upon png_color being any order */
+ palette[i].red = buf[0];
+ palette[i].green = buf[1];
+ palette[i].blue = buf[2];
+ }
+#endif
+
+ /* If we actually NEED the PLTE chunk (ie for a paletted image), we do
+ whatever the normal CRC configuration tells us. However, if we
+ have an RGB image, the PLTE can be considered ancillary, so
+ we will act as though it is. */
+#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#endif
+ {
+ png_crc_finish(png_ptr, 0);
+ }
+#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
+ else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */
+ {
+ /* If we don't want to use the data from an ancillary chunk,
+ we have two options: an error abort, or a warning and we
+ ignore the data in this chunk (which should be OK, since
+ it's considered ancillary for a RGB or RGBA image). */
+ if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE))
+ {
+ if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)
+ {
+ png_chunk_error(png_ptr, "CRC error");
+ }
+ else
+ {
+ png_chunk_warning(png_ptr, "CRC error");
+ return;
+ }
+ }
+ /* Otherwise, we (optionally) emit a warning and use the chunk. */
+ else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN))
+ {
+ png_chunk_warning(png_ptr, "CRC error");
+ }
+ }
+#endif
+
+ png_set_PLTE(png_ptr, info_ptr, palette, num);
+
+#if defined(PNG_READ_tRNS_SUPPORTED)
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+ {
+ if (png_ptr->num_trans > (png_uint_16)num)
+ {
+ png_warning(png_ptr, "Truncating incorrect tRNS chunk length");
+ png_ptr->num_trans = (png_uint_16)num;
+ }
+ if (info_ptr->num_trans > (png_uint_16)num)
+ {
+ png_warning(png_ptr, "Truncating incorrect info tRNS chunk length");
+ info_ptr->num_trans = (png_uint_16)num;
+ }
+ }
+ }
+#endif
+
+}
+
+void /* PRIVATE */
+png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_debug(1, "in png_handle_IEND\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT))
+ {
+ png_error(png_ptr, "No image in file");
+ }
+
+ png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
+
+ if (length != 0)
+ {
+ png_warning(png_ptr, "Incorrect IEND chunk length");
+ }
+ png_crc_finish(png_ptr, length);
+
+ if (&info_ptr == NULL) /* quiet compiler warnings about unused info_ptr */
+ return;
+}
+
+#if defined(PNG_READ_gAMA_SUPPORTED)
+void /* PRIVATE */
+png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_fixed_point igamma;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ float file_gamma;
+#endif
+ png_byte buf[4];
+
+ png_debug(1, "in png_handle_gAMA\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before gAMA");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid gAMA after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place gAMA chunk");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+#if defined(PNG_READ_sRGB_SUPPORTED)
+ && !(info_ptr->valid & PNG_INFO_sRGB)
+#endif
+ )
+ {
+ png_warning(png_ptr, "Duplicate gAMA chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 4)
+ {
+ png_warning(png_ptr, "Incorrect gAMA chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 4);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ igamma = (png_fixed_point)png_get_uint_32(buf);
+ /* check for zero gamma */
+ if (igamma == 0)
+ {
+ png_warning(png_ptr,
+ "Ignoring gAMA chunk with gamma=0");
+ return;
+ }
+
+#if defined(PNG_READ_sRGB_SUPPORTED)
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+ if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
+ {
+ png_warning(png_ptr,
+ "Ignoring incorrect gAMA value when sRGB is also present");
+#ifndef PNG_NO_CONSOLE_IO
+ fprintf(stderr, "gamma = (%d/100000)\n", (int)igamma);
+#endif
+ return;
+ }
+#endif /* PNG_READ_sRGB_SUPPORTED */
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ file_gamma = (float)igamma / (float)100000.0;
+# ifdef PNG_READ_GAMMA_SUPPORTED
+ png_ptr->gamma = file_gamma;
+# endif
+ png_set_gAMA(png_ptr, info_ptr, file_gamma);
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_set_gAMA_fixed(png_ptr, info_ptr, igamma);
+#endif
+}
+#endif
+
+#if defined(PNG_READ_sBIT_SUPPORTED)
+void /* PRIVATE */
+png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_size_t truelen;
+ png_byte buf[4];
+
+ png_debug(1, "in png_handle_sBIT\n");
+
+ buf[0] = buf[1] = buf[2] = buf[3] = 0;
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sBIT");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sBIT after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ {
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place sBIT chunk");
+ }
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT))
+ {
+ png_warning(png_ptr, "Duplicate sBIT chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ truelen = 3;
+ else
+ truelen = (png_size_t)png_ptr->channels;
+
+ if (length != truelen || length > 4)
+ {
+ png_warning(png_ptr, "Incorrect sBIT chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, truelen);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
+ {
+ png_ptr->sig_bit.red = buf[0];
+ png_ptr->sig_bit.green = buf[1];
+ png_ptr->sig_bit.blue = buf[2];
+ png_ptr->sig_bit.alpha = buf[3];
+ }
+ else
+ {
+ png_ptr->sig_bit.gray = buf[0];
+ png_ptr->sig_bit.red = buf[0];
+ png_ptr->sig_bit.green = buf[0];
+ png_ptr->sig_bit.blue = buf[0];
+ png_ptr->sig_bit.alpha = buf[1];
+ }
+ png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
+}
+#endif
+
+#if defined(PNG_READ_cHRM_SUPPORTED)
+void /* PRIVATE */
+png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[4];
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
+#endif
+ png_fixed_point int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
+ int_y_green, int_x_blue, int_y_blue;
+
+ png_uint_32 uint_x, uint_y;
+
+ png_debug(1, "in png_handle_cHRM\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before cHRM");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid cHRM after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Missing PLTE before cHRM");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)
+#if defined(PNG_READ_sRGB_SUPPORTED)
+ && !(info_ptr->valid & PNG_INFO_sRGB)
+#endif
+ )
+ {
+ png_warning(png_ptr, "Duplicate cHRM chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 32)
+ {
+ png_warning(png_ptr, "Incorrect cHRM chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 4);
+ uint_x = png_get_uint_32(buf);
+
+ png_crc_read(png_ptr, buf, 4);
+ uint_y = png_get_uint_32(buf);
+
+ if (uint_x > 80000L || uint_y > 80000L ||
+ uint_x + uint_y > 100000L)
+ {
+ png_warning(png_ptr, "Invalid cHRM white point");
+ png_crc_finish(png_ptr, 24);
+ return;
+ }
+ int_x_white = (png_fixed_point)uint_x;
+ int_y_white = (png_fixed_point)uint_y;
+
+ png_crc_read(png_ptr, buf, 4);
+ uint_x = png_get_uint_32(buf);
+
+ png_crc_read(png_ptr, buf, 4);
+ uint_y = png_get_uint_32(buf);
+
+ if (uint_x + uint_y > 100000L)
+ {
+ png_warning(png_ptr, "Invalid cHRM red point");
+ png_crc_finish(png_ptr, 16);
+ return;
+ }
+ int_x_red = (png_fixed_point)uint_x;
+ int_y_red = (png_fixed_point)uint_y;
+
+ png_crc_read(png_ptr, buf, 4);
+ uint_x = png_get_uint_32(buf);
+
+ png_crc_read(png_ptr, buf, 4);
+ uint_y = png_get_uint_32(buf);
+
+ if (uint_x + uint_y > 100000L)
+ {
+ png_warning(png_ptr, "Invalid cHRM green point");
+ png_crc_finish(png_ptr, 8);
+ return;
+ }
+ int_x_green = (png_fixed_point)uint_x;
+ int_y_green = (png_fixed_point)uint_y;
+
+ png_crc_read(png_ptr, buf, 4);
+ uint_x = png_get_uint_32(buf);
+
+ png_crc_read(png_ptr, buf, 4);
+ uint_y = png_get_uint_32(buf);
+
+ if (uint_x + uint_y > 100000L)
+ {
+ png_warning(png_ptr, "Invalid cHRM blue point");
+ png_crc_finish(png_ptr, 0);
+ return;
+ }
+ int_x_blue = (png_fixed_point)uint_x;
+ int_y_blue = (png_fixed_point)uint_y;
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ white_x = (float)int_x_white / (float)100000.0;
+ white_y = (float)int_y_white / (float)100000.0;
+ red_x = (float)int_x_red / (float)100000.0;
+ red_y = (float)int_y_red / (float)100000.0;
+ green_x = (float)int_x_green / (float)100000.0;
+ green_y = (float)int_y_green / (float)100000.0;
+ blue_x = (float)int_x_blue / (float)100000.0;
+ blue_y = (float)int_y_blue / (float)100000.0;
+#endif
+
+#if defined(PNG_READ_sRGB_SUPPORTED)
+ if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB))
+ {
+ if (PNG_OUT_OF_RANGE(int_x_white, 31270, 1000) ||
+ PNG_OUT_OF_RANGE(int_y_white, 32900, 1000) ||
+ PNG_OUT_OF_RANGE(int_x_red, 64000L, 1000) ||
+ PNG_OUT_OF_RANGE(int_y_red, 33000, 1000) ||
+ PNG_OUT_OF_RANGE(int_x_green, 30000, 1000) ||
+ PNG_OUT_OF_RANGE(int_y_green, 60000L, 1000) ||
+ PNG_OUT_OF_RANGE(int_x_blue, 15000, 1000) ||
+ PNG_OUT_OF_RANGE(int_y_blue, 6000, 1000))
+ {
+ png_warning(png_ptr,
+ "Ignoring incorrect cHRM value when sRGB is also present");
+#ifndef PNG_NO_CONSOLE_IO
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n",
+ white_x, white_y, red_x, red_y);
+ fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n",
+ green_x, green_y, blue_x, blue_y);
+#else
+ fprintf(stderr,"wx=%ld, wy=%ld, rx=%ld, ry=%ld\n",
+ int_x_white, int_y_white, int_x_red, int_y_red);
+ fprintf(stderr,"gx=%ld, gy=%ld, bx=%ld, by=%ld\n",
+ int_x_green, int_y_green, int_x_blue, int_y_blue);
+#endif
+#endif /* PNG_NO_CONSOLE_IO */
+ }
+ png_crc_finish(png_ptr, 0);
+ return;
+ }
+#endif /* PNG_READ_sRGB_SUPPORTED */
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ png_set_cHRM(png_ptr, info_ptr,
+ white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_set_cHRM_fixed(png_ptr, info_ptr,
+ int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
+ int_y_green, int_x_blue, int_y_blue);
+#endif
+ if (png_crc_finish(png_ptr, 0))
+ return;
+}
+#endif
+
+#if defined(PNG_READ_sRGB_SUPPORTED)
+void /* PRIVATE */
+png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ int intent;
+ png_byte buf[1];
+
+ png_debug(1, "in png_handle_sRGB\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sRGB");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sRGB after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place sRGB chunk");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
+ {
+ png_warning(png_ptr, "Duplicate sRGB chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 1)
+ {
+ png_warning(png_ptr, "Incorrect sRGB chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 1);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ intent = buf[0];
+ /* check for bad intent */
+ if (intent >= PNG_sRGB_INTENT_LAST)
+ {
+ png_warning(png_ptr, "Unknown sRGB intent");
+ return;
+ }
+
+#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
+ {
+ png_fixed_point igamma;
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ igamma=info_ptr->int_gamma;
+#else
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+ igamma=(png_fixed_point)(info_ptr->gamma * 100000.);
+# endif
+#endif
+ if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
+ {
+ png_warning(png_ptr,
+ "Ignoring incorrect gAMA value when sRGB is also present");
+#ifndef PNG_NO_CONSOLE_IO
+# ifdef PNG_FIXED_POINT_SUPPORTED
+ fprintf(stderr,"incorrect gamma=(%d/100000)\n",(int)png_ptr->int_gamma);
+# else
+# ifdef PNG_FLOATING_POINT_SUPPORTED
+ fprintf(stderr,"incorrect gamma=%f\n",png_ptr->gamma);
+# endif
+# endif
+#endif
+ }
+ }
+#endif /* PNG_READ_gAMA_SUPPORTED */
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+ if (PNG_OUT_OF_RANGE(info_ptr->int_x_white, 31270, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_y_white, 32900, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_x_red, 64000L, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_y_red, 33000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_x_green, 30000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_y_green, 60000L, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_x_blue, 15000, 1000) ||
+ PNG_OUT_OF_RANGE(info_ptr->int_y_blue, 6000, 1000))
+ {
+ png_warning(png_ptr,
+ "Ignoring incorrect cHRM value when sRGB is also present");
+ }
+#endif /* PNG_FIXED_POINT_SUPPORTED */
+#endif /* PNG_READ_cHRM_SUPPORTED */
+
+ png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
+}
+#endif /* PNG_READ_sRGB_SUPPORTED */
+
+#if defined(PNG_READ_iCCP_SUPPORTED)
+void /* PRIVATE */
+png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+ png_charp chunkdata;
+ png_byte compression_type;
+ png_bytep pC;
+ png_charp profile;
+ png_uint_32 skip = 0;
+ png_uint_32 profile_size, profile_length;
+ png_size_t slength, prefix_length, data_length;
+
+ png_debug(1, "in png_handle_iCCP\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before iCCP");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid iCCP after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->mode & PNG_HAVE_PLTE)
+ /* Should be an error, but we can cope with it */
+ png_warning(png_ptr, "Out of place iCCP chunk");
+
+ if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
+ {
+ png_warning(png_ptr, "Duplicate iCCP chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "iCCP chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, chunkdata);
+ return;
+ }
+
+ chunkdata[slength] = 0x00;
+
+ for (profile = chunkdata; *profile; profile++)
+ /* empty loop to find end of name */ ;
+
+ ++profile;
+
+ /* there should be at least one zero (the compression type byte)
+ following the separator, and we should be on it */
+ if ( profile >= chunkdata + slength)
+ {
+ png_free(png_ptr, chunkdata);
+ png_warning(png_ptr, "Malformed iCCP chunk");
+ return;
+ }
+
+ /* compression_type should always be zero */
+ compression_type = *profile++;
+ if (compression_type)
+ {
+ png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
+ compression_type=0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8
+ wrote nonzero) */
+ }
+
+ prefix_length = profile - chunkdata;
+ chunkdata = png_decompress_chunk(png_ptr, compression_type, chunkdata,
+ slength, prefix_length, &data_length);
+
+ profile_length = data_length - prefix_length;
+
+ if ( prefix_length > data_length || profile_length < 4)
+ {
+ png_free(png_ptr, chunkdata);
+ png_warning(png_ptr, "Profile size field missing from iCCP chunk");
+ return;
+ }
+
+ /* Check the profile_size recorded in the first 32 bits of the ICC profile */
+ pC = (png_bytep)(chunkdata+prefix_length);
+ profile_size = ((*(pC ))<<24) |
+ ((*(pC+1))<<16) |
+ ((*(pC+2))<< 8) |
+ ((*(pC+3)) );
+
+ if(profile_size < profile_length)
+ profile_length = profile_size;
+
+ if(profile_size > profile_length)
+ {
+ png_free(png_ptr, chunkdata);
+ png_warning(png_ptr, "Ignoring truncated iCCP profile.");
+ return;
+ }
+
+ png_set_iCCP(png_ptr, info_ptr, chunkdata, compression_type,
+ chunkdata + prefix_length, profile_length);
+ png_free(png_ptr, chunkdata);
+}
+#endif /* PNG_READ_iCCP_SUPPORTED */
+
+#if defined(PNG_READ_sPLT_SUPPORTED)
+void /* PRIVATE */
+png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+ png_bytep chunkdata;
+ png_bytep entry_start;
+ png_sPLT_t new_palette;
+#ifdef PNG_NO_POINTER_INDEXING
+ png_sPLT_entryp pp;
+#endif
+ int data_length, entry_size, i;
+ png_uint_32 skip = 0;
+ png_size_t slength;
+
+ png_debug(1, "in png_handle_sPLT\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sPLT");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sPLT after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "sPLT chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ chunkdata = (png_bytep)png_malloc(png_ptr, length + 1);
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, chunkdata);
+ return;
+ }
+
+ chunkdata[slength] = 0x00;
+
+ for (entry_start = chunkdata; *entry_start; entry_start++)
+ /* empty loop to find end of name */ ;
+ ++entry_start;
+
+ /* a sample depth should follow the separator, and we should be on it */
+ if (entry_start > chunkdata + slength)
+ {
+ png_free(png_ptr, chunkdata);
+ png_warning(png_ptr, "malformed sPLT chunk");
+ return;
+ }
+
+ new_palette.depth = *entry_start++;
+ entry_size = (new_palette.depth == 8 ? 6 : 10);
+ data_length = (slength - (entry_start - chunkdata));
+
+ /* integrity-check the data length */
+ if (data_length % entry_size)
+ {
+ png_free(png_ptr, chunkdata);
+ png_warning(png_ptr, "sPLT chunk has bad length");
+ return;
+ }
+
+ new_palette.nentries = (png_int_32) ( data_length / entry_size);
+ if ((png_uint_32) new_palette.nentries > (png_uint_32) (PNG_SIZE_MAX /
+ png_sizeof(png_sPLT_entry)))
+ {
+ png_warning(png_ptr, "sPLT chunk too long");
+ return;
+ }
+ new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
+ png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
+ if (new_palette.entries == NULL)
+ {
+ png_warning(png_ptr, "sPLT chunk requires too much memory");
+ return;
+ }
+
+#ifndef PNG_NO_POINTER_INDEXING
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+ png_sPLT_entryp pp = new_palette.entries + i;
+
+ if (new_palette.depth == 8)
+ {
+ pp->red = *entry_start++;
+ pp->green = *entry_start++;
+ pp->blue = *entry_start++;
+ pp->alpha = *entry_start++;
+ }
+ else
+ {
+ pp->red = png_get_uint_16(entry_start); entry_start += 2;
+ pp->green = png_get_uint_16(entry_start); entry_start += 2;
+ pp->blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
+ pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+#else
+ pp = new_palette.entries;
+ for (i = 0; i < new_palette.nentries; i++)
+ {
+
+ if (new_palette.depth == 8)
+ {
+ pp[i].red = *entry_start++;
+ pp[i].green = *entry_start++;
+ pp[i].blue = *entry_start++;
+ pp[i].alpha = *entry_start++;
+ }
+ else
+ {
+ pp[i].red = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].blue = png_get_uint_16(entry_start); entry_start += 2;
+ pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
+ }
+ pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+ }
+#endif
+
+ /* discard all chunk data except the name and stash that */
+ new_palette.name = (png_charp)chunkdata;
+
+ png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
+
+ png_free(png_ptr, chunkdata);
+ png_free(png_ptr, new_palette.entries);
+}
+#endif /* PNG_READ_sPLT_SUPPORTED */
+
+#if defined(PNG_READ_tRNS_SUPPORTED)
+void /* PRIVATE */
+png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
+
+ png_debug(1, "in png_handle_tRNS\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before tRNS");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid tRNS after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+ {
+ png_warning(png_ptr, "Duplicate tRNS chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ png_byte buf[2];
+
+ if (length != 2)
+ {
+ png_warning(png_ptr, "Incorrect tRNS chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 2);
+ png_ptr->num_trans = 1;
+ png_ptr->trans_values.gray = png_get_uint_16(buf);
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ png_byte buf[6];
+
+ if (length != 6)
+ {
+ png_warning(png_ptr, "Incorrect tRNS chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ png_crc_read(png_ptr, buf, (png_size_t)length);
+ png_ptr->num_trans = 1;
+ png_ptr->trans_values.red = png_get_uint_16(buf);
+ png_ptr->trans_values.green = png_get_uint_16(buf + 2);
+ png_ptr->trans_values.blue = png_get_uint_16(buf + 4);
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (!(png_ptr->mode & PNG_HAVE_PLTE))
+ {
+ /* Should be an error, but we can cope with it. */
+ png_warning(png_ptr, "Missing PLTE before tRNS");
+ }
+ if (length > (png_uint_32)png_ptr->num_palette ||
+ length > PNG_MAX_PALETTE_LENGTH)
+ {
+ png_warning(png_ptr, "Incorrect tRNS chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ if (length == 0)
+ {
+ png_warning(png_ptr, "Zero length tRNS chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ png_crc_read(png_ptr, readbuf, (png_size_t)length);
+ png_ptr->num_trans = (png_uint_16)length;
+ }
+ else
+ {
+ png_warning(png_ptr, "tRNS chunk not allowed with alpha channel");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
+ &(png_ptr->trans_values));
+}
+#endif
+
+#if defined(PNG_READ_bKGD_SUPPORTED)
+void /* PRIVATE */
+png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_size_t truelen;
+ png_byte buf[6];
+
+ png_debug(1, "in png_handle_bKGD\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before bKGD");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid bKGD after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE))
+ {
+ png_warning(png_ptr, "Missing PLTE before bKGD");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD))
+ {
+ png_warning(png_ptr, "Duplicate bKGD chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ truelen = 1;
+ else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
+ truelen = 6;
+ else
+ truelen = 2;
+
+ if (length != truelen)
+ {
+ png_warning(png_ptr, "Incorrect bKGD chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, truelen);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ /* We convert the index value into RGB components so that we can allow
+ * arbitrary RGB values for background when we have transparency, and
+ * so it is easy to determine the RGB values of the background color
+ * from the info_ptr struct. */
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_ptr->background.index = buf[0];
+ if(info_ptr->num_palette)
+ {
+ if(buf[0] > info_ptr->num_palette)
+ {
+ png_warning(png_ptr, "Incorrect bKGD chunk index value");
+ return;
+ }
+ png_ptr->background.red =
+ (png_uint_16)png_ptr->palette[buf[0]].red;
+ png_ptr->background.green =
+ (png_uint_16)png_ptr->palette[buf[0]].green;
+ png_ptr->background.blue =
+ (png_uint_16)png_ptr->palette[buf[0]].blue;
+ }
+ }
+ else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
+ {
+ png_ptr->background.red =
+ png_ptr->background.green =
+ png_ptr->background.blue =
+ png_ptr->background.gray = png_get_uint_16(buf);
+ }
+ else
+ {
+ png_ptr->background.red = png_get_uint_16(buf);
+ png_ptr->background.green = png_get_uint_16(buf + 2);
+ png_ptr->background.blue = png_get_uint_16(buf + 4);
+ }
+
+ png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background));
+}
+#endif
+
+#if defined(PNG_READ_hIST_SUPPORTED)
+void /* PRIVATE */
+png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ unsigned int num, i;
+ png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
+
+ png_debug(1, "in png_handle_hIST\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before hIST");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid hIST after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (!(png_ptr->mode & PNG_HAVE_PLTE))
+ {
+ png_warning(png_ptr, "Missing PLTE before hIST");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST))
+ {
+ png_warning(png_ptr, "Duplicate hIST chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ num = length / 2 ;
+ if (num != (unsigned int) png_ptr->num_palette || num >
+ (unsigned int) PNG_MAX_PALETTE_LENGTH)
+ {
+ png_warning(png_ptr, "Incorrect hIST chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ for (i = 0; i < num; i++)
+ {
+ png_byte buf[2];
+
+ png_crc_read(png_ptr, buf, 2);
+ readbuf[i] = png_get_uint_16(buf);
+ }
+
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ png_set_hIST(png_ptr, info_ptr, readbuf);
+}
+#endif
+
+#if defined(PNG_READ_pHYs_SUPPORTED)
+void /* PRIVATE */
+png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[9];
+ png_uint_32 res_x, res_y;
+ int unit_type;
+
+ png_debug(1, "in png_handle_pHYs\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before pHYs");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid pHYs after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+ {
+ png_warning(png_ptr, "Duplicate pHYs chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 9)
+ {
+ png_warning(png_ptr, "Incorrect pHYs chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 9);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ res_x = png_get_uint_32(buf);
+ res_y = png_get_uint_32(buf + 4);
+ unit_type = buf[8];
+ png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
+}
+#endif
+
+#if defined(PNG_READ_oFFs_SUPPORTED)
+void /* PRIVATE */
+png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[9];
+ png_int_32 offset_x, offset_y;
+ int unit_type;
+
+ png_debug(1, "in png_handle_oFFs\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before oFFs");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid oFFs after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+ {
+ png_warning(png_ptr, "Duplicate oFFs chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (length != 9)
+ {
+ png_warning(png_ptr, "Incorrect oFFs chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 9);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ offset_x = png_get_int_32(buf);
+ offset_y = png_get_int_32(buf + 4);
+ unit_type = buf[8];
+ png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
+}
+#endif
+
+#if defined(PNG_READ_pCAL_SUPPORTED)
+/* read the pCAL chunk (described in the PNG Extensions document) */
+void /* PRIVATE */
+png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_charp purpose;
+ png_int_32 X0, X1;
+ png_byte type, nparams;
+ png_charp buf, units, endptr;
+ png_charpp params;
+ png_size_t slength;
+ int i;
+
+ png_debug(1, "in png_handle_pCAL\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before pCAL");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid pCAL after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL))
+ {
+ png_warning(png_ptr, "Duplicate pCAL chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_debug1(2, "Allocating and reading pCAL chunk data (%lu bytes)\n",
+ length + 1);
+ purpose = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ if (purpose == NULL)
+ {
+ png_warning(png_ptr, "No memory for pCAL purpose.");
+ return;
+ }
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)purpose, slength);
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, purpose);
+ return;
+ }
+
+ purpose[slength] = 0x00; /* null terminate the last string */
+
+ png_debug(3, "Finding end of pCAL purpose string\n");
+ for (buf = purpose; *buf; buf++)
+ /* empty loop */ ;
+
+ endptr = purpose + slength;
+
+ /* We need to have at least 12 bytes after the purpose string
+ in order to get the parameter information. */
+ if (endptr <= buf + 12)
+ {
+ png_warning(png_ptr, "Invalid pCAL data");
+ png_free(png_ptr, purpose);
+ return;
+ }
+
+ png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n");
+ X0 = png_get_int_32((png_bytep)buf+1);
+ X1 = png_get_int_32((png_bytep)buf+5);
+ type = buf[9];
+ nparams = buf[10];
+ units = buf + 11;
+
+ png_debug(3, "Checking pCAL equation type and number of parameters\n");
+ /* Check that we have the right number of parameters for known
+ equation types. */
+ if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
+ (type == PNG_EQUATION_BASE_E && nparams != 3) ||
+ (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
+ (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
+ {
+ png_warning(png_ptr, "Invalid pCAL parameters for equation type");
+ png_free(png_ptr, purpose);
+ return;
+ }
+ else if (type >= PNG_EQUATION_LAST)
+ {
+ png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
+ }
+
+ for (buf = units; *buf; buf++)
+ /* Empty loop to move past the units string. */ ;
+
+ png_debug(3, "Allocating pCAL parameters array\n");
+ params = (png_charpp)png_malloc_warn(png_ptr, (png_uint_32)(nparams
+ *png_sizeof(png_charp))) ;
+ if (params == NULL)
+ {
+ png_free(png_ptr, purpose);
+ png_warning(png_ptr, "No memory for pCAL params.");
+ return;
+ }
+
+ /* Get pointers to the start of each parameter string. */
+ for (i = 0; i < (int)nparams; i++)
+ {
+ buf++; /* Skip the null string terminator from previous parameter. */
+
+ png_debug1(3, "Reading pCAL parameter %d\n", i);
+ for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++)
+ /* Empty loop to move past each parameter string */ ;
+
+ /* Make sure we haven't run out of data yet */
+ if (buf > endptr)
+ {
+ png_warning(png_ptr, "Invalid pCAL data");
+ png_free(png_ptr, purpose);
+ png_free(png_ptr, params);
+ return;
+ }
+ }
+
+ png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams,
+ units, params);
+
+ png_free(png_ptr, purpose);
+ png_free(png_ptr, params);
+}
+#endif
+
+#if defined(PNG_READ_sCAL_SUPPORTED)
+/* read the sCAL chunk */
+void /* PRIVATE */
+png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_charp buffer, ep;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ double width, height;
+ png_charp vp;
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_charp swidth, sheight;
+#endif
+#endif
+ png_size_t slength;
+
+ png_debug(1, "in png_handle_sCAL\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before sCAL");
+ else if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ png_warning(png_ptr, "Invalid sCAL after IDAT");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL))
+ {
+ png_warning(png_ptr, "Duplicate sCAL chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)\n",
+ length + 1);
+ buffer = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ if (buffer == NULL)
+ {
+ png_warning(png_ptr, "Out of memory while processing sCAL chunk");
+ return;
+ }
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)buffer, slength);
+
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, buffer);
+ return;
+ }
+
+ buffer[slength] = 0x00; /* null terminate the last string */
+
+ ep = buffer + 1; /* skip unit byte */
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ width = png_strtod(png_ptr, ep, &vp);
+ if (*vp)
+ {
+ png_warning(png_ptr, "malformed width string in sCAL chunk");
+ return;
+ }
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ swidth = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
+ if (swidth == NULL)
+ {
+ png_warning(png_ptr, "Out of memory while processing sCAL chunk width");
+ return;
+ }
+ png_memcpy(swidth, ep, (png_size_t)png_strlen(ep));
+#endif
+#endif
+
+ for (ep = buffer; *ep; ep++)
+ /* empty loop */ ;
+ ep++;
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ height = png_strtod(png_ptr, ep, &vp);
+ if (*vp)
+ {
+ png_warning(png_ptr, "malformed height string in sCAL chunk");
+ return;
+ }
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ sheight = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
+ if (swidth == NULL)
+ {
+ png_warning(png_ptr, "Out of memory while processing sCAL chunk height");
+ return;
+ }
+ png_memcpy(sheight, ep, (png_size_t)png_strlen(ep));
+#endif
+#endif
+
+ if (buffer + slength < ep
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ || width <= 0. || height <= 0.
+#endif
+ )
+ {
+ png_warning(png_ptr, "Invalid sCAL data");
+ png_free(png_ptr, buffer);
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+ png_free(png_ptr, swidth);
+ png_free(png_ptr, sheight);
+#endif
+ return;
+ }
+
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ png_set_sCAL(png_ptr, info_ptr, buffer[0], width, height);
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ png_set_sCAL_s(png_ptr, info_ptr, buffer[0], swidth, sheight);
+#endif
+#endif
+
+ png_free(png_ptr, buffer);
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+ png_free(png_ptr, swidth);
+ png_free(png_ptr, sheight);
+#endif
+}
+#endif
+
+#if defined(PNG_READ_tIME_SUPPORTED)
+void /* PRIVATE */
+png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_byte buf[7];
+ png_time mod_time;
+
+ png_debug(1, "in png_handle_tIME\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Out of place tIME chunk");
+ else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME))
+ {
+ png_warning(png_ptr, "Duplicate tIME chunk");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+ if (length != 7)
+ {
+ png_warning(png_ptr, "Incorrect tIME chunk length");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+
+ png_crc_read(png_ptr, buf, 7);
+ if (png_crc_finish(png_ptr, 0))
+ return;
+
+ mod_time.second = buf[6];
+ mod_time.minute = buf[5];
+ mod_time.hour = buf[4];
+ mod_time.day = buf[3];
+ mod_time.month = buf[2];
+ mod_time.year = png_get_uint_16(buf);
+
+ png_set_tIME(png_ptr, info_ptr, &mod_time);
+}
+#endif
+
+#if defined(PNG_READ_tEXt_SUPPORTED)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_textp text_ptr;
+ png_charp key;
+ png_charp text;
+ png_uint_32 skip = 0;
+ png_size_t slength;
+ int ret;
+
+ png_debug(1, "in png_handle_tEXt\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before tEXt");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "tEXt chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ key = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ if (key == NULL)
+ {
+ png_warning(png_ptr, "No memory to process text chunk.");
+ return;
+ }
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)key, slength);
+
+ if (png_crc_finish(png_ptr, skip))
+ {
+ png_free(png_ptr, key);
+ return;
+ }
+
+ key[slength] = 0x00;
+
+ for (text = key; *text; text++)
+ /* empty loop to find end of key */ ;
+
+ if (text != key + slength)
+ text++;
+
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ (png_uint_32)png_sizeof(png_text));
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr, "Not enough memory to process text chunk.");
+ png_free(png_ptr, key);
+ return;
+ }
+ text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr->key = key;
+#ifdef PNG_iTXt_SUPPORTED
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+ text_ptr->itxt_length = 0;
+#endif
+ text_ptr->text = text;
+ text_ptr->text_length = png_strlen(text);
+
+ ret=png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, key);
+ png_free(png_ptr, text_ptr);
+ if (ret)
+ png_warning(png_ptr, "Insufficient memory to process text chunk.");
+}
+#endif
+
+#if defined(PNG_READ_zTXt_SUPPORTED)
+/* note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_textp text_ptr;
+ png_charp chunkdata;
+ png_charp text;
+ int comp_type;
+ int ret;
+ png_size_t slength, prefix_len, data_len;
+
+ png_debug(1, "in png_handle_zTXt\n");
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before zTXt");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ /* We will no doubt have problems with chunks even half this size, but
+ there is no hard and fast rule to tell us where to stop. */
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr,"zTXt chunk too large to fit in memory");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#endif
+
+ chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ if (chunkdata == NULL)
+ {
+ png_warning(png_ptr,"Out of memory processing zTXt chunk.");
+ return;
+ }
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, chunkdata);
+ return;
+ }
+
+ chunkdata[slength] = 0x00;
+
+ for (text = chunkdata; *text; text++)
+ /* empty loop */ ;
+
+ /* zTXt must have some text after the chunkdataword */
+ if (text == chunkdata + slength)
+ {
+ comp_type = PNG_TEXT_COMPRESSION_NONE;
+ png_warning(png_ptr, "Zero length zTXt chunk");
+ }
+ else
+ {
+ comp_type = *(++text);
+ if (comp_type != PNG_TEXT_COMPRESSION_zTXt)
+ {
+ png_warning(png_ptr, "Unknown compression type in zTXt chunk");
+ comp_type = PNG_TEXT_COMPRESSION_zTXt;
+ }
+ text++; /* skip the compression_method byte */
+ }
+ prefix_len = text - chunkdata;
+
+ chunkdata = (png_charp)png_decompress_chunk(png_ptr, comp_type, chunkdata,
+ (png_size_t)length, prefix_len, &data_len);
+
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ (png_uint_32)png_sizeof(png_text));
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr,"Not enough memory to process zTXt chunk.");
+ png_free(png_ptr, chunkdata);
+ return;
+ }
+ text_ptr->compression = comp_type;
+ text_ptr->key = chunkdata;
+#ifdef PNG_iTXt_SUPPORTED
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+ text_ptr->itxt_length = 0;
+#endif
+ text_ptr->text = chunkdata + prefix_len;
+ text_ptr->text_length = data_len;
+
+ ret=png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, text_ptr);
+ png_free(png_ptr, chunkdata);
+ if (ret)
+ png_error(png_ptr, "Insufficient memory to store zTXt chunk.");
+}
+#endif
+
+#if defined(PNG_READ_iTXt_SUPPORTED)
+/* note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_textp text_ptr;
+ png_charp chunkdata;
+ png_charp key, lang, text, lang_key;
+ int comp_flag;
+ int comp_type = 0;
+ int ret;
+ png_size_t slength, prefix_len, data_len;
+
+ png_debug(1, "in png_handle_iTXt\n");
+
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before iTXt");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+ /* We will no doubt have problems with chunks even half this size, but
+ there is no hard and fast rule to tell us where to stop. */
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr,"iTXt chunk too large to fit in memory");
+ png_crc_finish(png_ptr, length);
+ return;
+ }
+#endif
+
+ chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+ if (chunkdata == NULL)
+ {
+ png_warning(png_ptr, "No memory to process iTXt chunk.");
+ return;
+ }
+ slength = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+ if (png_crc_finish(png_ptr, 0))
+ {
+ png_free(png_ptr, chunkdata);
+ return;
+ }
+
+ chunkdata[slength] = 0x00;
+
+ for (lang = chunkdata; *lang; lang++)
+ /* empty loop */ ;
+ lang++; /* skip NUL separator */
+
+ /* iTXt must have a language tag (possibly empty), two compression bytes,
+ translated keyword (possibly empty), and possibly some text after the
+ keyword */
+
+ if (lang >= chunkdata + slength)
+ {
+ comp_flag = PNG_TEXT_COMPRESSION_NONE;
+ png_warning(png_ptr, "Zero length iTXt chunk");
+ }
+ else
+ {
+ comp_flag = *lang++;
+ comp_type = *lang++;
+ }
+
+ for (lang_key = lang; *lang_key; lang_key++)
+ /* empty loop */ ;
+ lang_key++; /* skip NUL separator */
+
+ for (text = lang_key; *text; text++)
+ /* empty loop */ ;
+ text++; /* skip NUL separator */
+
+ prefix_len = text - chunkdata;
+
+ key=chunkdata;
+ if (comp_flag)
+ chunkdata = png_decompress_chunk(png_ptr, comp_type, chunkdata,
+ (size_t)length, prefix_len, &data_len);
+ else
+ data_len=png_strlen(chunkdata + prefix_len);
+ text_ptr = (png_textp)png_malloc_warn(png_ptr,
+ (png_uint_32)png_sizeof(png_text));
+ if (text_ptr == NULL)
+ {
+ png_warning(png_ptr,"Not enough memory to process iTXt chunk.");
+ png_free(png_ptr, chunkdata);
+ return;
+ }
+ text_ptr->compression = (int)comp_flag + 1;
+ text_ptr->lang_key = chunkdata+(lang_key-key);
+ text_ptr->lang = chunkdata+(lang-key);
+ text_ptr->itxt_length = data_len;
+ text_ptr->text_length = 0;
+ text_ptr->key = chunkdata;
+ text_ptr->text = chunkdata + prefix_len;
+
+ ret=png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, text_ptr);
+ png_free(png_ptr, chunkdata);
+ if (ret)
+ png_error(png_ptr, "Insufficient memory to store iTXt chunk.");
+}
+#endif
+
+/* This function is called when we haven't found a handler for a
+ chunk. If there isn't a problem with the chunk itself (ie bad
+ chunk name, CRC, or a critical chunk), the chunk is silently ignored
+ -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which
+ case it will be saved away to be written out later. */
+void /* PRIVATE */
+png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+ png_uint_32 skip = 0;
+
+ png_debug(1, "in png_handle_unknown\n");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+#ifdef PNG_USE_LOCAL_ARRAYS
+ PNG_IDAT;
+#endif
+ if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* not an IDAT */
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ }
+
+ png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+
+ if (!(png_ptr->chunk_name[0] & 0x20))
+ {
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+ if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+ && png_ptr->read_user_chunk_fn == NULL
+#endif
+ )
+#endif
+ png_chunk_error(png_ptr, "unknown critical chunk");
+ }
+
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+ if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) ||
+ (png_ptr->read_user_chunk_fn != NULL))
+ {
+ png_unknown_chunk chunk;
+
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "unknown chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+ png_strcpy((png_charp)chunk.name, (png_charp)png_ptr->chunk_name);
+ chunk.data = (png_bytep)png_malloc(png_ptr, length);
+ chunk.size = (png_size_t)length;
+ png_crc_read(png_ptr, (png_bytep)chunk.data, length);
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+ if(png_ptr->read_user_chunk_fn != NULL)
+ {
+ /* callback to user unknown chunk handler */
+ if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 0)
+ {
+ if (!(png_ptr->chunk_name[0] & 0x20))
+ if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS)
+ {
+ png_free(png_ptr, chunk.data);
+ png_chunk_error(png_ptr, "unknown critical chunk");
+ }
+ png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
+ }
+ }
+ else
+#endif
+ png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
+ png_free(png_ptr, chunk.data);
+ }
+ else
+#endif
+ skip = length;
+
+ png_crc_finish(png_ptr, skip);
+
+#if !defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+ if (&info_ptr == NULL) /* quiet compiler warnings about unused info_ptr */
+ return;
+#endif
+}
+
+/* This function is called to verify that a chunk name is valid.
+ This function can't have the "critical chunk check" incorporated
+ into it, since in the future we will need to be able to call user
+ functions to handle unknown critical chunks after we check that
+ the chunk name itself is valid. */
+
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+
+void /* PRIVATE */
+png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
+{
+ png_debug(1, "in png_check_chunk_name\n");
+ if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) ||
+ isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3]))
+ {
+ png_chunk_error(png_ptr, "invalid chunk type");
+ }
+}
+
+/* Combines the row recently read in with the existing pixels in the
+ row. This routine takes care of alpha and transparency if requested.
+ This routine also handles the two methods of progressive display
+ of interlaced images, depending on the mask value.
+ The mask value describes which pixels are to be combined with
+ the row. The pattern always repeats every 8 pixels, so just 8
+ bits are needed. A one indicates the pixel is to be combined,
+ a zero indicates the pixel is to be skipped. This is in addition
+ to any alpha or transparency value associated with the pixel. If
+ you want all pixels to be combined, pass 0xff (255) in mask. */
+#ifndef PNG_HAVE_MMX_COMBINE_ROW
+void /* PRIVATE */
+png_combine_row(png_structp png_ptr, png_bytep row, int mask)
+{
+ png_debug(1,"in png_combine_row\n");
+ if (mask == 0xff)
+ {
+ png_memcpy(row, png_ptr->row_buf + 1,
+ PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width));
+ }
+ else
+ {
+ switch (png_ptr->row_info.pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ int s_inc, s_start, s_end;
+ int m = 0x80;
+ int shift;
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 7;
+ s_inc = 1;
+ }
+ else
+#endif
+ {
+ s_start = 7;
+ s_end = 0;
+ s_inc = -1;
+ }
+
+ shift = s_start;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ int value;
+
+ value = (*sp >> shift) & 0x01;
+ *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+ else
+ shift += s_inc;
+
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+ case 2:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ int s_start, s_end, s_inc;
+ int m = 0x80;
+ int shift;
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+ int value;
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 6;
+ s_inc = 2;
+ }
+ else
+#endif
+ {
+ s_start = 6;
+ s_end = 0;
+ s_inc = -2;
+ }
+
+ shift = s_start;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+ else
+ shift += s_inc;
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+ case 4:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ int s_start, s_end, s_inc;
+ int m = 0x80;
+ int shift;
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+ int value;
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ {
+ s_start = 0;
+ s_end = 4;
+ s_inc = 4;
+ }
+ else
+#endif
+ {
+ s_start = 4;
+ s_end = 0;
+ s_inc = -4;
+ }
+ shift = s_start;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ value = (*sp >> shift) & 0xf;
+ *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+ *dp |= (png_byte)(value << shift);
+ }
+
+ if (shift == s_end)
+ {
+ shift = s_start;
+ sp++;
+ dp++;
+ }
+ else
+ shift += s_inc;
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+ default:
+ {
+ png_bytep sp = png_ptr->row_buf + 1;
+ png_bytep dp = row;
+ png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
+ png_uint_32 i;
+ png_uint_32 row_width = png_ptr->width;
+ png_byte m = 0x80;
+
+
+ for (i = 0; i < row_width; i++)
+ {
+ if (m & mask)
+ {
+ png_memcpy(dp, sp, pixel_bytes);
+ }
+
+ sp += pixel_bytes;
+ dp += pixel_bytes;
+
+ if (m == 1)
+ m = 0x80;
+ else
+ m >>= 1;
+ }
+ break;
+ }
+ }
+ }
+}
+#endif /* !PNG_HAVE_MMX_COMBINE_ROW */
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+#ifndef PNG_HAVE_MMX_READ_INTERLACE /* else in pngvcrd.c, pnggccrd.c */
+/* OLD pre-1.0.9 interface:
+void png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+ png_uint_32 transformations)
+ */
+void /* PRIVATE */
+png_do_read_interlace(png_structp png_ptr)
+{
+ png_row_infop row_info = &(png_ptr->row_info);
+ png_bytep row = png_ptr->row_buf + 1;
+ int pass = png_ptr->pass;
+ png_uint_32 transformations = png_ptr->transformations;
+#ifdef PNG_USE_LOCAL_ARRAYS
+ /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+ /* offset to next interlace block */
+ const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+#endif
+
+ png_debug(1,"in png_do_read_interlace (stock C version)\n");
+ if (row != NULL && row_info != NULL)
+ {
+ png_uint_32 final_width;
+
+ final_width = row_info->width * png_pass_inc[pass];
+
+ switch (row_info->pixel_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
+ png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ int jstop = png_pass_inc[pass];
+ png_byte v;
+ png_uint_32 i;
+ int j;
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (transformations & PNG_PACKSWAP)
+ {
+ sshift = (int)((row_info->width + 7) & 0x07);
+ dshift = (int)((final_width + 7) & 0x07);
+ s_start = 7;
+ s_end = 0;
+ s_inc = -1;
+ }
+ else
+#endif
+ {
+ sshift = 7 - (int)((row_info->width + 7) & 0x07);
+ dshift = 7 - (int)((final_width + 7) & 0x07);
+ s_start = 0;
+ s_end = 7;
+ s_inc = 1;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ v = (png_byte)((*sp >> sshift) & 0x01);
+ for (j = 0; j < jstop; j++)
+ {
+ *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+ else
+ dshift += s_inc;
+ }
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+ case 2:
+ {
+ png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
+ png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ int jstop = png_pass_inc[pass];
+ png_uint_32 i;
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (transformations & PNG_PACKSWAP)
+ {
+ sshift = (int)(((row_info->width + 3) & 0x03) << 1);
+ dshift = (int)(((final_width + 3) & 0x03) << 1);
+ s_start = 6;
+ s_end = 0;
+ s_inc = -2;
+ }
+ else
+#endif
+ {
+ sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
+ dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
+ s_start = 0;
+ s_end = 6;
+ s_inc = 2;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v;
+ int j;
+
+ v = (png_byte)((*sp >> sshift) & 0x03);
+ for (j = 0; j < jstop; j++)
+ {
+ *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+ else
+ dshift += s_inc;
+ }
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+ case 4:
+ {
+ png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
+ png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
+ int sshift, dshift;
+ int s_start, s_end, s_inc;
+ png_uint_32 i;
+ int jstop = png_pass_inc[pass];
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (transformations & PNG_PACKSWAP)
+ {
+ sshift = (int)(((row_info->width + 1) & 0x01) << 2);
+ dshift = (int)(((final_width + 1) & 0x01) << 2);
+ s_start = 4;
+ s_end = 0;
+ s_inc = -4;
+ }
+ else
+#endif
+ {
+ sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
+ dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
+ s_start = 0;
+ s_end = 4;
+ s_inc = 4;
+ }
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v = (png_byte)((*sp >> sshift) & 0xf);
+ int j;
+
+ for (j = 0; j < jstop; j++)
+ {
+ *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff);
+ *dp |= (png_byte)(v << dshift);
+ if (dshift == s_end)
+ {
+ dshift = s_start;
+ dp--;
+ }
+ else
+ dshift += s_inc;
+ }
+ if (sshift == s_end)
+ {
+ sshift = s_start;
+ sp--;
+ }
+ else
+ sshift += s_inc;
+ }
+ break;
+ }
+ default:
+ {
+ png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
+ png_bytep sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes;
+ png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
+
+ int jstop = png_pass_inc[pass];
+ png_uint_32 i;
+
+ for (i = 0; i < row_info->width; i++)
+ {
+ png_byte v[8];
+ int j;
+
+ png_memcpy(v, sp, pixel_bytes);
+ for (j = 0; j < jstop; j++)
+ {
+ png_memcpy(dp, v, pixel_bytes);
+ dp -= pixel_bytes;
+ }
+ sp -= pixel_bytes;
+ }
+ break;
+ }
+ }
+ row_info->width = final_width;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,final_width);
+ }
+#if !defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (&transformations == NULL) /* silence compiler warning */
+ return;
+#endif
+}
+#endif /* !PNG_HAVE_MMX_READ_INTERLACE */
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
+
+#ifndef PNG_HAVE_MMX_READ_FILTER_ROW
+void /* PRIVATE */
+png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
+ png_bytep prev_row, int filter)
+{
+ png_debug(1, "in png_read_filter_row\n");
+ png_debug2(2,"row = %lu, filter = %d\n", png_ptr->row_number, filter);
+ switch (filter)
+ {
+ case PNG_FILTER_VALUE_NONE:
+ break;
+ case PNG_FILTER_VALUE_SUB:
+ {
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+ png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+ png_bytep rp = row + bpp;
+ png_bytep lp = row;
+
+ for (i = bpp; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff);
+ rp++;
+ }
+ break;
+ }
+ case PNG_FILTER_VALUE_UP:
+ {
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+ png_bytep rp = row;
+ png_bytep pp = prev_row;
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+ rp++;
+ }
+ break;
+ }
+ case PNG_FILTER_VALUE_AVG:
+ {
+ png_uint_32 i;
+ png_bytep rp = row;
+ png_bytep pp = prev_row;
+ png_bytep lp = row;
+ png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+ png_uint_32 istop = row_info->rowbytes - bpp;
+
+ for (i = 0; i < bpp; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ ((int)(*pp++) / 2 )) & 0xff);
+ rp++;
+ }
+
+ for (i = 0; i < istop; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) +
+ (int)(*pp++ + *lp++) / 2 ) & 0xff);
+ rp++;
+ }
+ break;
+ }
+ case PNG_FILTER_VALUE_PAETH:
+ {
+ png_uint_32 i;
+ png_bytep rp = row;
+ png_bytep pp = prev_row;
+ png_bytep lp = row;
+ png_bytep cp = prev_row;
+ png_uint_32 bpp = (row_info->pixel_depth + 7) >> 3;
+ png_uint_32 istop=row_info->rowbytes - bpp;
+
+ for (i = 0; i < bpp; i++)
+ {
+ *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+ rp++;
+ }
+
+ for (i = 0; i < istop; i++) /* use leftover rp,pp */
+ {
+ int a, b, c, pa, pb, pc, p;
+
+ a = *lp++;
+ b = *pp++;
+ c = *cp++;
+
+ 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
+
+ /*
+ if (pa <= pb && pa <= pc)
+ p = a;
+ else if (pb <= pc)
+ p = b;
+ else
+ p = c;
+ */
+
+ p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+
+ *rp = (png_byte)(((int)(*rp) + p) & 0xff);
+ rp++;
+ }
+ break;
+ }
+ default:
+ png_warning(png_ptr, "Ignoring bad adaptive filter type");
+ *row=0;
+ break;
+ }
+}
+#endif /* !PNG_HAVE_MMX_READ_FILTER_ROW */
+
+void /* PRIVATE */
+png_read_finish_row(png_structp png_ptr)
+{
+#ifdef PNG_USE_LOCAL_ARRAYS
+ /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* start of interlace block */
+ const int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* offset to next interlace block */
+ const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* start of interlace block in the y direction */
+ const int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* offset to next interlace block in the y direction */
+ const int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
+ png_debug(1, "in png_read_finish_row\n");
+ png_ptr->row_number++;
+ if (png_ptr->row_number < png_ptr->num_rows)
+ return;
+
+ if (png_ptr->interlaced)
+ {
+ png_ptr->row_number = 0;
+ png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+ do
+ {
+ png_ptr->pass++;
+ if (png_ptr->pass >= 7)
+ break;
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
+ png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1;
+
+ if (!(png_ptr->transformations & PNG_INTERLACE))
+ {
+ 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->num_rows))
+ continue;
+ }
+ else /* if (png_ptr->transformations & PNG_INTERLACE) */
+ break;
+ } while (png_ptr->iwidth == 0);
+
+ if (png_ptr->pass < 7)
+ return;
+ }
+
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+ {
+#ifdef PNG_USE_LOCAL_ARRAYS
+ PNG_IDAT;
+#endif
+ char extra;
+ int ret;
+
+ png_ptr->zstream.next_out = (Byte *)&extra;
+ png_ptr->zstream.avail_out = (uInt)1;
+ for(;;)
+ {
+ if (!(png_ptr->zstream.avail_in))
+ {
+ while (!png_ptr->idat_size)
+ {
+ png_byte chunk_length[4];
+
+ png_crc_finish(png_ptr, 0);
+
+ png_read_data(png_ptr, chunk_length, 4);
+ png_ptr->idat_size = png_get_uint_31(png_ptr, chunk_length);
+ png_reset_crc(png_ptr);
+ png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+ if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
+ png_error(png_ptr, "Not enough image data");
+
+ }
+ png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
+ png_ptr->zstream.next_in = png_ptr->zbuf;
+ if (png_ptr->zbuf_size > png_ptr->idat_size)
+ png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
+ png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in);
+ png_ptr->idat_size -= png_ptr->zstream.avail_in;
+ }
+ ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+ if (ret == Z_STREAM_END)
+ {
+ if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in ||
+ png_ptr->idat_size)
+ png_warning(png_ptr, "Extra compressed data");
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ break;
+ }
+ if (ret != Z_OK)
+ png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
+ "Decompression Error");
+
+ if (!(png_ptr->zstream.avail_out))
+ {
+ png_warning(png_ptr, "Extra compressed data.");
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ break;
+ }
+
+ }
+ png_ptr->zstream.avail_out = 0;
+ }
+
+ if (png_ptr->idat_size || png_ptr->zstream.avail_in)
+ png_warning(png_ptr, "Extra compression data");
+
+ inflateReset(&png_ptr->zstream);
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+}
+
+void /* PRIVATE */
+png_read_start_row(png_structp png_ptr)
+{
+#ifdef PNG_USE_LOCAL_ARRAYS
+ /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* start of interlace block */
+ const int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* offset to next interlace block */
+ const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* start of interlace block in the y direction */
+ const int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* offset to next interlace block in the y direction */
+ const int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
+ int max_pixel_depth;
+ png_uint_32 row_bytes;
+
+ png_debug(1, "in png_read_start_row\n");
+ png_ptr->zstream.avail_in = 0;
+ png_init_read_transformations(png_ptr);
+ if (png_ptr->interlaced)
+ {
+ if (!(png_ptr->transformations & PNG_INTERLACE))
+ png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+ png_pass_ystart[0]) / png_pass_yinc[0];
+ else
+ png_ptr->num_rows = png_ptr->height;
+
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[png_ptr->pass] - 1 -
+ png_pass_start[png_ptr->pass]) /
+ png_pass_inc[png_ptr->pass];
+
+ row_bytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->iwidth) + 1;
+
+ png_ptr->irowbytes = (png_size_t)row_bytes;
+ if((png_uint_32)png_ptr->irowbytes != row_bytes)
+ png_error(png_ptr, "Rowbytes overflow in png_read_start_row");
+ }
+ else
+ {
+ png_ptr->num_rows = png_ptr->height;
+ png_ptr->iwidth = png_ptr->width;
+ png_ptr->irowbytes = png_ptr->rowbytes + 1;
+ }
+ max_pixel_depth = png_ptr->pixel_depth;
+
+#if defined(PNG_READ_PACK_SUPPORTED)
+ if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8)
+ max_pixel_depth = 8;
+#endif
+
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+ if (png_ptr->transformations & PNG_EXPAND)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (png_ptr->num_trans)
+ max_pixel_depth = 32;
+ else
+ max_pixel_depth = 24;
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (max_pixel_depth < 8)
+ max_pixel_depth = 8;
+ if (png_ptr->num_trans)
+ max_pixel_depth *= 2;
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (png_ptr->num_trans)
+ {
+ max_pixel_depth *= 4;
+ max_pixel_depth /= 3;
+ }
+ }
+ }
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED)
+ if (png_ptr->transformations & (PNG_FILLER))
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ max_pixel_depth = 32;
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (max_pixel_depth <= 8)
+ max_pixel_depth = 16;
+ else
+ max_pixel_depth = 32;
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (max_pixel_depth <= 32)
+ max_pixel_depth = 32;
+ else
+ max_pixel_depth = 64;
+ }
+ }
+#endif
+
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+ if (png_ptr->transformations & PNG_GRAY_TO_RGB)
+ {
+ if (
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+ (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
+#endif
+#if defined(PNG_READ_FILLER_SUPPORTED)
+ (png_ptr->transformations & (PNG_FILLER)) ||
+#endif
+ png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (max_pixel_depth <= 16)
+ max_pixel_depth = 32;
+ else
+ max_pixel_depth = 64;
+ }
+ else
+ {
+ if (max_pixel_depth <= 8)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 32;
+ else
+ max_pixel_depth = 24;
+ }
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ max_pixel_depth = 64;
+ else
+ max_pixel_depth = 48;
+ }
+ }
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
+defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+ if(png_ptr->transformations & PNG_USER_TRANSFORM)
+ {
+ int user_pixel_depth=png_ptr->user_transform_depth*
+ png_ptr->user_transform_channels;
+ if(user_pixel_depth > max_pixel_depth)
+ max_pixel_depth=user_pixel_depth;
+ }
+#endif
+
+ /* align the width on the next larger 8 pixels. Mainly used
+ for interlacing */
+ row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
+ /* calculate the maximum bytes needed, adding a byte and a pixel
+ for safety's sake */
+ row_bytes = PNG_ROWBYTES(max_pixel_depth,row_bytes) +
+ 1 + ((max_pixel_depth + 7) >> 3);
+#ifdef PNG_MAX_MALLOC_64K
+ if (row_bytes > (png_uint_32)65536L)
+ png_error(png_ptr, "This image requires a row greater than 64KB");
+#endif
+ png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes+64);
+ png_ptr->row_buf = png_ptr->big_row_buf+32;
+#if defined(PNG_DEBUG) && defined(PNG_USE_PNGGCCRD)
+ png_ptr->row_buf_size = row_bytes;
+#endif
+
+#ifdef PNG_MAX_MALLOC_64K
+ if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L)
+ png_error(png_ptr, "This image requires a row greater than 64KB");
+#endif
+ if ((png_uint_32)png_ptr->rowbytes > (png_uint_32)(PNG_SIZE_MAX - 1))
+ png_error(png_ptr, "Row has too many bytes to allocate in memory.");
+ png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)(
+ png_ptr->rowbytes + 1));
+
+ png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+ png_debug1(3, "width = %lu,\n", png_ptr->width);
+ png_debug1(3, "height = %lu,\n", png_ptr->height);
+ png_debug1(3, "iwidth = %lu,\n", png_ptr->iwidth);
+ png_debug1(3, "num_rows = %lu\n", png_ptr->num_rows);
+ png_debug1(3, "rowbytes = %lu,\n", png_ptr->rowbytes);
+ png_debug1(3, "irowbytes = %lu,\n", png_ptr->irowbytes);
+
+ png_ptr->flags |= PNG_FLAG_ROW_INIT;
+}
+#endif /* PNG_READ_SUPPORTED */
+