void png_read_filter_row_paeth4_sse2(png_row_infop row_info, png_bytep row,
png_const_bytep prev)
{
/* Paeth tries to predict pixel d using the pixel to the left of it, a,
* and two pixels from the previous row, b and c:
* prev: c b
* row: a d
* The Paeth function predicts d to be whichever of a, b, or c is nearest to
* p=a+b-c.
*
* The first pixel has no left context, and so uses an Up filter, p = b.
* This works naturally with our main loop's p = a+b-c if we force a and c
* to zero.
* Here we zero b and d, which become c and a respectively at the start of
* the loop.
*/
png_size_t rb;
const __m128i zero = _mm_setzero_si128();
__m128i pa,pb,pc,smallest,nearest;
__m128i c, b = zero,
a, d = zero;
png_debug(1, "in png_read_filter_row_paeth4_sse2");
rb = row_info->rowbytes+4;
while (rb > 4) {
/* It's easiest to do this math (particularly, deal with pc) with 16-bit
* intermediates.
*/
c = b; b = _mm_unpacklo_epi8(load4(prev), zero);
a = d; d = _mm_unpacklo_epi8(load4(row ), zero);
/* (p-a) == (a+b-c - a) == (b-c) */
pa = _mm_sub_epi16(b,c);
/* (p-b) == (a+b-c - b) == (a-c) */
pb = _mm_sub_epi16(a,c);
/* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
pc = _mm_add_epi16(pa,pb);
pa = abs_i16(pa); /* |p-a| */
pb = abs_i16(pb); /* |p-b| */
pc = abs_i16(pc); /* |p-c| */
smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));
/* Paeth breaks ties favoring a over b over c. */
nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
c));
/* Note `_epi8`: we need addition to wrap modulo 255. */
d = _mm_add_epi8(d, nearest);
store4(row, _mm_packus_epi16(d,d));
prev += 4;
row += 4;
rb -= 4;
}
}
/* Allow the application to select one or more row filters to use. */
void
png_set_filter(png_structp png_ptr, int method, int filters)
{
png_debug(1, "in png_set_filter\n");
/* We allow 'method' only for future expansion of the base filter method. */
if (method == PNG_FILTER_TYPE_BASE)
{
switch (filters & (PNG_ALL_FILTERS | 0x07))
{
case 5:
case 6:
case 7: png_warning(png_ptr, "Unknown row filter for method 0");
case PNG_FILTER_VALUE_NONE: png_ptr->do_filter=PNG_FILTER_NONE; break;
case PNG_FILTER_VALUE_SUB: png_ptr->do_filter=PNG_FILTER_SUB; break;
case PNG_FILTER_VALUE_UP: png_ptr->do_filter=PNG_FILTER_UP; break;
case PNG_FILTER_VALUE_AVG: png_ptr->do_filter=PNG_FILTER_AVG; break;
case PNG_FILTER_VALUE_PAETH: png_ptr->do_filter=PNG_FILTER_PAETH;break;
default: png_ptr->do_filter = (png_byte)filters; break;
}
/* If we have allocated the row_buf, this means we have already started
* with the image and we should have allocated all of the filter buffers
* that have been selected. If prev_row isn't already allocated, then
* it is too late to start using the filters that need it, since we
* will be missing the data in the previous row. If an application
* wants to start and stop using particular filters during compression,
* it should start out with all of the filters, and then add and
* remove them after the start of compression.
*/
if (png_ptr->row_buf != NULL)
{
if (png_ptr->do_filter & PNG_FILTER_SUB && png_ptr->sub_row == NULL)
{
png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
(png_ptr->rowbytes + 1));
png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
}
if (png_ptr->do_filter & PNG_FILTER_UP && png_ptr->up_row == NULL)
{
if (png_ptr->prev_row == NULL)
{
png_warning(png_ptr, "Can't add Up filter after starting");
png_ptr->do_filter &= ~PNG_FILTER_UP;
}
else
{
png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
(png_ptr->rowbytes + 1));
png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
}
}
if (png_ptr->do_filter & PNG_FILTER_AVG && png_ptr->avg_row == NULL)
{
if (png_ptr->prev_row == NULL)
{
png_warning(png_ptr, "Can't add Average filter after starting");
png_ptr->do_filter &= ~PNG_FILTER_AVG;
}
else
{
png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
(png_ptr->rowbytes + 1));
png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
}
}
if (png_ptr->do_filter & PNG_FILTER_PAETH &&
png_ptr->paeth_row == NULL)
{
if (png_ptr->prev_row == NULL)
{
png_warning(png_ptr, "Can't add Paeth filter after starting");
png_ptr->do_filter &= ~PNG_FILTER_PAETH;
}
else
{
png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
(png_ptr->rowbytes + 1));
png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
}
}
if (png_ptr->do_filter == PNG_NO_FILTERS)
png_ptr->do_filter = PNG_FILTER_NONE;
}
}
else
png_error(png_ptr, "Unknown custom filter method");
}
/* Read the information before the actual image data. This has been
* changed in v0.90 to allow reading a file that already has the magic
* bytes read from the stream. You can tell libpng how many bytes have
* been read from the beginning of the stream (up to the maximum of 8)
* via png_set_sig_bytes(), and we will only check the remaining bytes
* here. The application can then have access to the signature bytes we
* read if it is determined that this isn't a valid PNG file.
*/
void PNGAPI
png_read_info(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_info\n");
/* If we haven't checked all of the PNG signature bytes, do so now. */
if (png_ptr->sig_bytes < 8)
{
png_size_t num_checked = png_ptr->sig_bytes,
num_to_check = 8 - num_checked;
png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
png_ptr->sig_bytes = 8;
if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
{
if (num_checked < 4 &&
png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
png_error(png_ptr, "Not a PNG file");
else
png_error(png_ptr, "PNG file corrupted by ASCII conversion");
}
if (num_checked < 3)
png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
}
for(;;)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_IHDR;
PNG_IDAT;
PNG_IEND;
PNG_PLTE;
#if defined(PNG_READ_bKGD_SUPPORTED)
PNG_bKGD;
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
PNG_cHRM;
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
PNG_gAMA;
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
PNG_hIST;
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
PNG_iCCP;
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
PNG_iTXt;
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
PNG_oFFs;
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
PNG_pCAL;
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
PNG_pHYs;
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
PNG_sBIT;
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
PNG_sCAL;
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
PNG_sPLT;
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
PNG_sRGB;
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
PNG_tEXt;
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
PNG_tIME;
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
PNG_tRNS;
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
PNG_zTXt;
#endif
#endif /* PNG_GLOBAL_ARRAYS */
png_byte chunk_length[4];
png_uint_32 length;
png_read_data(png_ptr, chunk_length, 4);
length = png_get_uint_31(png_ptr,chunk_length);
png_reset_crc(png_ptr);
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
//.........这里部分代码省略.........
/* Read the information before the actual image data. This has been
* changed in v0.90 to allow reading a file that already has the magic
* bytes read from the stream. You can tell libpng how many bytes have
* been read from the beginning of the stream (up to the maximum of 8)
* via png_set_sig_bytes(), and we will only check the remaining bytes
* here. The application can then have access to the signature bytes we
* read if it is determined that this isn't a valid PNG file.
*/
void PNGAPI
png_read_info(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_info");
if (png_ptr == NULL || info_ptr == NULL)
return;
/* If we haven't checked all of the PNG signature bytes, do so now. */
if (png_ptr->sig_bytes < 8)
{
png_size_t num_checked = png_ptr->sig_bytes,
num_to_check = 8 - num_checked;
#ifdef PNG_IO_STATE_SUPPORTED
png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
#endif
png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
png_ptr->sig_bytes = 8;
if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
{
if (num_checked < 4 &&
png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
png_error(png_ptr, "Not a PNG file");
else
png_error(png_ptr, "PNG file corrupted by ASCII conversion");
}
if (num_checked < 3)
png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
}
for (;;)
{
PNG_IHDR;
PNG_IDAT;
PNG_IEND;
PNG_PLTE;
#ifdef PNG_READ_bKGD_SUPPORTED
PNG_bKGD;
#endif
#ifdef PNG_READ_cHRM_SUPPORTED
PNG_cHRM;
#endif
#ifdef PNG_READ_gAMA_SUPPORTED
PNG_gAMA;
#endif
#ifdef PNG_READ_hIST_SUPPORTED
PNG_hIST;
#endif
#ifdef PNG_READ_iCCP_SUPPORTED
PNG_iCCP;
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
PNG_iTXt;
#endif
#ifdef PNG_READ_oFFs_SUPPORTED
PNG_oFFs;
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
PNG_pCAL;
#endif
#ifdef PNG_READ_pHYs_SUPPORTED
PNG_pHYs;
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
PNG_sBIT;
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
PNG_sCAL;
#endif
#ifdef PNG_READ_sPLT_SUPPORTED
PNG_sPLT;
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
PNG_sRGB;
#endif
#ifdef PNG_READ_tEXt_SUPPORTED
PNG_tEXt;
#endif
#ifdef PNG_READ_tIME_SUPPORTED
PNG_tIME;
#endif
#ifdef PNG_READ_tRNS_SUPPORTED
PNG_tRNS;
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
PNG_zTXt;
#endif
png_uint_32 length = png_read_chunk_header(png_ptr);
PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
//.........这里部分代码省略.........
void
png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
{
/* The switch statement is compiled in for ARM_NEON_API, the call to
* png_have_neon is compiled in for ARM_NEON_CHECK. If both are defined
* the check is only performed if the API has not set the NEON option on
* or off explicitly. In this case the check controls what happens.
*
* If the CHECK is not compiled in and the option is UNSET the behavior prior
* to 1.6.7 was to use the NEON code - this was a bug caused by having the
* wrong order of the 'ON' and 'default' cases. UNSET now defaults to OFF,
* as documented in png.h
*/
png_debug(1, "in png_init_filter_functions_neon");
#ifdef PNG_ARM_NEON_API_SUPPORTED
switch ((pp->options >> PNG_ARM_NEON) & 3)
{
case PNG_OPTION_UNSET:
/* Allow the run-time check to execute if it has been enabled -
* thus both API and CHECK can be turned on. If it isn't supported
* this case will fall through to the 'default' below, which just
* returns.
*/
#endif /* PNG_ARM_NEON_API_SUPPORTED */
#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
{
static volatile sig_atomic_t no_neon = -1; /* not checked */
if (no_neon < 0)
no_neon = !png_have_neon(pp);
if (no_neon)
return;
}
#ifdef PNG_ARM_NEON_API_SUPPORTED
break;
#endif
#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
#ifdef PNG_ARM_NEON_API_SUPPORTED
default: /* OFF or INVALID */
return;
case PNG_OPTION_ON:
/* Option turned on */
break;
}
#endif
/* IMPORTANT: any new external functions used here must be declared using
* PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the
* 'prefix' option to configure works:
*
* ./configure --with-libpng-prefix=foobar_
*
* Verify you have got this right by running the above command, doing a build
* and examining pngprefix.h; it must contain a #define for every external
* function you add. (Notice that this happens automatically for the
* initialization function.)
*/
pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
if (bpp == 3)
{
pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
png_read_filter_row_paeth3_neon;
}
else if (bpp == 4)
{
pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
png_read_filter_row_paeth4_neon;
}
}
/* 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' buffer must be 80 characters in size (for the keyword plus a
* trailing '\0'). If this routine returns 0 then there was no keyword, or a
* valid one could not be generated, and the caller must png_error.
*/
png_uint_32 /* PRIVATE */
png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
{
png_const_charp orig_key = key;
png_uint_32 key_len = 0;
int bad_character = 0;
int space = 1;
png_debug(1, "in png_check_keyword");
if (key == NULL)
{
*new_key = 0;
return 0;
}
while (*key && key_len < 79)
{
png_byte ch = (png_byte)*key++;
if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
*new_key++ = ch, ++key_len, space = 0;
else if (space == 0)
{
/* A space or an invalid character when one wasn't seen immediately
* before; output just a space.
*/
*new_key++ = 32, ++key_len, space = 1;
/* If the character was not a space then it is invalid. */
if (ch != 32)
bad_character = ch;
}
else if (bad_character == 0)
bad_character = ch; /* just skip it, record the first error */
}
if (key_len > 0 && space != 0) /* trailing space */
{
--key_len, --new_key;
if (bad_character == 0)
bad_character = 32;
}
/* Terminate the keyword */
*new_key = 0;
if (key_len == 0)
return 0;
#ifdef PNG_WARNINGS_SUPPORTED
/* Try to only output one warning per keyword: */
if (*key != 0) /* keyword too long */
png_warning(png_ptr, "keyword truncated");
else if (bad_character != 0)
{
PNG_WARNING_PARAMETERS(p)
png_warning_parameter(p, 1, orig_key);
png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);
png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '[email protected]'");
}
#endif /* WARNINGS */
return key_len;
}
/* Alternate create PNG structure for reading, and allocate any memory needed. */
png_structp PNGAPI
png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
png_malloc_ptr malloc_fn, png_free_ptr free_fn)
{
#endif /* PNG_USER_MEM_SUPPORTED */
#ifdef PNG_SETJMP_SUPPORTED
volatile
#endif
png_structp png_ptr;
volatile int png_cleanup_needed = 0;
#ifdef PNG_SETJMP_SUPPORTED
#ifdef USE_FAR_KEYWORD
jmp_buf jmpbuf;
#endif
#endif
int i;
png_debug(1, "in png_create_read_struct");
#ifdef PNG_USER_MEM_SUPPORTED
png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
malloc_fn, mem_ptr);
#else
png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
#endif
if (png_ptr == NULL)
return (NULL);
/* Added at libpng-1.2.6 */
#ifdef PNG_SET_USER_LIMITS_SUPPORTED
png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
/* Added at libpng-1.4.0 */
png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;
#endif
#ifdef PNG_SETJMP_SUPPORTED
/* Applications that neglect to set up their own setjmp() and then
encounter a png_error() will longjmp here. Since the jmpbuf is
then meaningless we abort instead of returning. */
#ifdef USE_FAR_KEYWORD
if (setjmp(jmpbuf))
#else
if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */
#endif
PNG_ABORT();
#ifdef USE_FAR_KEYWORD
png_memcpy(png_jmpbuf(png_ptr), jmpbuf, png_sizeof(jmp_buf));
#endif
#endif /* PNG_SETJMP_SUPPORTED */
#ifdef PNG_USER_MEM_SUPPORTED
png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
#endif
png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
if (user_png_ver)
{
i = 0;
do
{
if (user_png_ver[i] != png_libpng_ver[i])
png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
} while (png_libpng_ver[i++]);
}
else
png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
{
/* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
* we must recompile any applications that use any older library version.
* For versions after libpng 1.0, we will be compatible, so we need
* only check the first digit.
*/
if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
(user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
(user_png_ver[0] == '0' && user_png_ver[2] < '9'))
{
#ifdef PNG_STDIO_SUPPORTED
char msg[80];
if (user_png_ver)
{
png_snprintf(msg, 80,
"Application was compiled with png.h from libpng-%.20s",
user_png_ver);
png_warning(png_ptr, msg);
}
png_snprintf(msg, 80,
"Application is running with png.c from libpng-%.20s",
png_libpng_ver);
png_warning(png_ptr, msg);
#endif
//.........这里部分代码省略.........
开发者ID:0w，项目名称:moai-dev，代码行数:101，代码来源:pngread.c
示例17: png_read_destroy
/* free all memory used by the read (old method) */
void /* PRIVATE */
png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)
{
#ifdef PNG_SETJMP_SUPPORTED
jmp_buf tmp_jmp;
#endif
png_error_ptr error_fn;
png_error_ptr warning_fn;
png_voidp error_ptr;
#ifdef PNG_USER_MEM_SUPPORTED
png_free_ptr free_fn;
#endif
png_debug(1, "in png_read_destroy\n");
if (info_ptr != NULL)
png_info_destroy(png_ptr, info_ptr);
if (end_info_ptr != NULL)
png_info_destroy(png_ptr, end_info_ptr);
png_free(png_ptr, png_ptr->zbuf);
png_free(png_ptr, png_ptr->big_row_buf);
png_free(png_ptr, png_ptr->prev_row);
#if defined(PNG_READ_DITHER_SUPPORTED)
png_free(png_ptr, png_ptr->palette_lookup);
png_free(png_ptr, png_ptr->dither_index);
#endif
#if defined(PNG_READ_GAMMA_SUPPORTED)
png_free(png_ptr, png_ptr->gamma_table);
#endif
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
png_free(png_ptr, png_ptr->gamma_from_1);
png_free(png_ptr, png_ptr->gamma_to_1);
#endif
#ifdef PNG_FREE_ME_SUPPORTED
if (png_ptr->free_me & PNG_FREE_PLTE)
png_zfree(png_ptr, png_ptr->palette);
png_ptr->free_me &= ~PNG_FREE_PLTE;
#else
if (png_ptr->flags & PNG_FLAG_FREE_PLTE)
png_zfree(png_ptr, png_ptr->palette);
png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
#endif
#if defined(PNG_tRNS_SUPPORTED) || \
defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
#ifdef PNG_FREE_ME_SUPPORTED
if (png_ptr->free_me & PNG_FREE_TRNS)
png_free(png_ptr, png_ptr->trans);
png_ptr->free_me &= ~PNG_FREE_TRNS;
#else
if (png_ptr->flags & PNG_FLAG_FREE_TRNS)
png_free(png_ptr, png_ptr->trans);
png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
#endif
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
#ifdef PNG_FREE_ME_SUPPORTED
if (png_ptr->free_me & PNG_FREE_HIST)
png_free(png_ptr, png_ptr->hist);
png_ptr->free_me &= ~PNG_FREE_HIST;
#else
if (png_ptr->flags & PNG_FLAG_FREE_HIST)
png_free(png_ptr, png_ptr->hist);
png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
#endif
#endif
#if defined(PNG_READ_GAMMA_SUPPORTED)
if (png_ptr->gamma_16_table != NULL)
{
int i;
int istop = (1 << (8 - png_ptr->gamma_shift));
for (i = 0; i < istop; i++)
{
png_free(png_ptr, png_ptr->gamma_16_table[i]);
}
png_free(png_ptr, png_ptr->gamma_16_table);
}
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
if (png_ptr->gamma_16_from_1 != NULL)
{
int i;
int istop = (1 << (8 - png_ptr->gamma_shift));
for (i = 0; i < istop; i++)
{
png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
}
png_free(png_ptr, png_ptr->gamma_16_from_1);
}
if (png_ptr->gamma_16_to_1 != NULL)
{
int i;
int istop = (1 << (8 - png_ptr->gamma_shift));
for (i = 0; i < istop; i++)
{
png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
}
png_free(png_ptr, png_ptr->gamma_16_to_1);
}
#endif
//.........这里部分代码省略.........
/* Read the end of the PNG file. Will not read past the end of the
* file, will verify the end is accurate, and will read any comments
* or time information at the end of the file, if info is not NULL.
*/
void PNGAPI
png_read_end(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_end");
if (png_ptr == NULL)
return;
png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
do
{
PNG_IHDR;
PNG_IDAT;
PNG_IEND;
PNG_PLTE;
#ifdef PNG_READ_bKGD_SUPPORTED
PNG_bKGD;
#endif
#ifdef PNG_READ_cHRM_SUPPORTED
PNG_cHRM;
#endif
#ifdef PNG_READ_gAMA_SUPPORTED
PNG_gAMA;
#endif
#ifdef PNG_READ_hIST_SUPPORTED
PNG_hIST;
#endif
#ifdef PNG_READ_iCCP_SUPPORTED
PNG_iCCP;
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
PNG_iTXt;
#endif
#ifdef PNG_READ_oFFs_SUPPORTED
PNG_oFFs;
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
PNG_pCAL;
#endif
#ifdef PNG_READ_pHYs_SUPPORTED
PNG_pHYs;
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
PNG_sBIT;
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
PNG_sCAL;
#endif
#ifdef PNG_READ_sPLT_SUPPORTED
PNG_sPLT;
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
PNG_sRGB;
#endif
#ifdef PNG_READ_tEXt_SUPPORTED
PNG_tEXt;
#endif
#ifdef PNG_READ_tIME_SUPPORTED
PNG_tIME;
#endif
#ifdef PNG_READ_tRNS_SUPPORTED
PNG_tRNS;
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
PNG_zTXt;
#endif
png_uint_32 length = png_read_chunk_header(png_ptr);
PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
if (!png_memcmp(chunk_name, png_IHDR, 4))
png_handle_IHDR(png_ptr, info_ptr, length);
else if (!png_memcmp(chunk_name, png_IEND, 4))
png_handle_IEND(png_ptr, info_ptr, length);
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
else if (png_handle_as_unknown(png_ptr, chunk_name))
{
if (!png_memcmp(chunk_name, png_IDAT, 4))
{
if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
png_benign_error(png_ptr, "Too many IDATs found");
}
png_handle_unknown(png_ptr, info_ptr, length);
if (!png_memcmp(chunk_name, png_PLTE, 4))
png_ptr->mode |= PNG_HAVE_PLTE;
}
#endif
else if (!png_memcmp(chunk_name, png_IDAT, 4))
{
/* Zero length IDATs are legal after the last IDAT has been
* read, but not after other chunks have been read.
*/
if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
png_benign_error(png_ptr, "Too many IDATs found");
png_crc_finish(png_ptr, length);
}
else if (!png_memcmp(chunk_name, png_PLTE, 4))
//.........这里部分代码省略.........
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