--- /dev/null
+Index: LICENSE
+===================================================================
+--- LICENSE
++++ LICENSE
+@@ -8,6 +8,12 @@
+ If you modify libpng you may insert additional notices immediately following
+ this sentence.
+
++This modified version of libpng code adds animated PNG support and is
++released under the libpng license described below. The modifications are
++Copyright (c) 2006-2007 Andrew Smith, Copyright (c) 2008-2017 Max Stepin,
++and are delimited by "#ifdef PNG_APNG_SUPPORTED / #endif" directives
++surrounding them in the modified libpng source files.
++
+ This code is released under the libpng license.
+
+ libpng versions 1.0.7, July 1, 2000 through 1.6.30, June 28, 2017 are
+Index: pngread.c
+===================================================================
+--- pngread.c
++++ pngread.c
+@@ -161,6 +161,9 @@
+
+ else if (chunk_name == png_IDAT)
+ {
++#ifdef PNG_READ_APNG_SUPPORTED
++ png_have_info(png_ptr, info_ptr);
++#endif
+ png_ptr->idat_size = length;
+ break;
+ }
+@@ -250,6 +253,17 @@
+ png_handle_iTXt(png_ptr, info_ptr, length);
+ #endif
+
++#ifdef PNG_READ_APNG_SUPPORTED
++ else if (chunk_name == png_acTL)
++ png_handle_acTL(png_ptr, info_ptr, length);
++
++ else if (chunk_name == png_fcTL)
++ png_handle_fcTL(png_ptr, info_ptr, length);
++
++ else if (chunk_name == png_fdAT)
++ png_handle_fdAT(png_ptr, info_ptr, length);
++#endif
++
+ else
+ png_handle_unknown(png_ptr, info_ptr, length,
+ PNG_HANDLE_CHUNK_AS_DEFAULT);
+@@ -257,6 +271,72 @@
+ }
+ #endif /* SEQUENTIAL_READ */
+
++#ifdef PNG_READ_APNG_SUPPORTED
++void PNGAPI
++png_read_frame_head(png_structp png_ptr, png_infop info_ptr)
++{
++ png_byte have_chunk_after_DAT; /* after IDAT or after fdAT */
++
++ png_debug(0, "Reading frame head");
++
++ if ((png_ptr->mode & PNG_HAVE_acTL) == 0)
++ png_error(png_ptr, "attempt to png_read_frame_head() but "
++ "no acTL present");
++
++ /* do nothing for the main IDAT */
++ if (png_ptr->num_frames_read == 0)
++ return;
++
++ png_read_reset(png_ptr);
++ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
++ png_ptr->mode &= ~PNG_HAVE_fcTL;
++
++ have_chunk_after_DAT = 0;
++ for (;;)
++ {
++ png_uint_32 length = png_read_chunk_header(png_ptr);
++
++ if (png_ptr->chunk_name == png_IDAT)
++ {
++ /* discard trailing IDATs for the first frame */
++ if (have_chunk_after_DAT != 0 || png_ptr->num_frames_read > 1)
++ png_error(png_ptr, "png_read_frame_head(): out of place IDAT");
++ png_crc_finish(png_ptr, length);
++ }
++
++ else if (png_ptr->chunk_name == png_fcTL)
++ {
++ png_handle_fcTL(png_ptr, info_ptr, length);
++ have_chunk_after_DAT = 1;
++ }
++
++ else if (png_ptr->chunk_name == png_fdAT)
++ {
++ png_ensure_sequence_number(png_ptr, length);
++
++ /* discard trailing fdATs for frames other than the first */
++ if (have_chunk_after_DAT == 0 && png_ptr->num_frames_read > 1)
++ png_crc_finish(png_ptr, length - 4);
++ else if (png_ptr->mode & PNG_HAVE_fcTL)
++ {
++ png_ptr->idat_size = length - 4;
++ png_ptr->mode |= PNG_HAVE_IDAT;
++
++ break;
++ }
++ else
++ png_error(png_ptr, "png_read_frame_head(): out of place fdAT");
++ }
++ else
++ {
++ png_warning(png_ptr, "Skipped (ignored) a chunk "
++ "between APNG chunks");
++ png_crc_finish(png_ptr, length);
++ }
++ }
++}
++#endif /* READ_APNG */
++
+ /* Optional call to update the users info_ptr structure */
+ void PNGAPI
+ png_read_update_info(png_structrp png_ptr, png_inforp info_ptr)
+Index: pngget.c
+===================================================================
+--- pngget.c
++++ pngget.c
+@@ -1216,4 +1216,166 @@
+ # endif
+ #endif
+
++#ifdef PNG_APNG_SUPPORTED
++png_uint_32 PNGAPI
++png_get_acTL(png_structp png_ptr, png_infop info_ptr,
++ png_uint_32 *num_frames, png_uint_32 *num_plays)
++{
++ png_debug1(1, "in %s retrieval function", "acTL");
++
++ if (png_ptr != NULL && info_ptr != NULL &&
++ (info_ptr->valid & PNG_INFO_acTL) != 0 &&
++ num_frames != NULL && num_plays != NULL)
++ {
++ *num_frames = info_ptr->num_frames;
++ *num_plays = info_ptr->num_plays;
++ return (1);
++ }
++
++ return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_num_frames(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_get_num_frames()");
++
++ if (png_ptr != NULL && info_ptr != NULL)
++ return (info_ptr->num_frames);
++ return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_num_plays(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_get_num_plays()");
++
++ if (png_ptr != NULL && info_ptr != NULL)
++ return (info_ptr->num_plays);
++ return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr,
++ png_uint_32 *width, png_uint_32 *height,
++ png_uint_32 *x_offset, png_uint_32 *y_offset,
++ png_uint_16 *delay_num, png_uint_16 *delay_den,
++ png_byte *dispose_op, png_byte *blend_op)
++{
++ png_debug1(1, "in %s retrieval function", "fcTL");
++
++ if (png_ptr != NULL && info_ptr != NULL &&
++ (info_ptr->valid & PNG_INFO_fcTL) != 0 &&
++ width != NULL && height != NULL &&
++ x_offset != NULL && y_offset != NULL &&
++ delay_num != NULL && delay_den != NULL &&
++ dispose_op != NULL && blend_op != NULL)
++ {
++ *width = info_ptr->next_frame_width;
++ *height = info_ptr->next_frame_height;
++ *x_offset = info_ptr->next_frame_x_offset;
++ *y_offset = info_ptr->next_frame_y_offset;
++ *delay_num = info_ptr->next_frame_delay_num;
++ *delay_den = info_ptr->next_frame_delay_den;
++ *dispose_op = info_ptr->next_frame_dispose_op;
++ *blend_op = info_ptr->next_frame_blend_op;
++ return (1);
++ }
++
++ return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_next_frame_width(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_get_next_frame_width()");
++
++ if (png_ptr != NULL && info_ptr != NULL)
++ return (info_ptr->next_frame_width);
++ return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_next_frame_height(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_get_next_frame_height()");
++
++ if (png_ptr != NULL && info_ptr != NULL)
++ return (info_ptr->next_frame_height);
++ return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_next_frame_x_offset(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_get_next_frame_x_offset()");
++
++ if (png_ptr != NULL && info_ptr != NULL)
++ return (info_ptr->next_frame_x_offset);
++ return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_next_frame_y_offset(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_get_next_frame_y_offset()");
++
++ if (png_ptr != NULL && info_ptr != NULL)
++ return (info_ptr->next_frame_y_offset);
++ return (0);
++}
++
++png_uint_16 PNGAPI
++png_get_next_frame_delay_num(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_get_next_frame_delay_num()");
++
++ if (png_ptr != NULL && info_ptr != NULL)
++ return (info_ptr->next_frame_delay_num);
++ return (0);
++}
++
++png_uint_16 PNGAPI
++png_get_next_frame_delay_den(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_get_next_frame_delay_den()");
++
++ if (png_ptr != NULL && info_ptr != NULL)
++ return (info_ptr->next_frame_delay_den);
++ return (0);
++}
++
++png_byte PNGAPI
++png_get_next_frame_dispose_op(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_get_next_frame_dispose_op()");
++
++ if (png_ptr != NULL && info_ptr != NULL)
++ return (info_ptr->next_frame_dispose_op);
++ return (0);
++}
++
++png_byte PNGAPI
++png_get_next_frame_blend_op(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_get_next_frame_blend_op()");
++
++ if (png_ptr != NULL && info_ptr != NULL)
++ return (info_ptr->next_frame_blend_op);
++ return (0);
++}
++
++png_byte PNGAPI
++png_get_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_first_frame_is_hidden()");
++
++ if (png_ptr != NULL)
++ return (png_byte)(png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN);
++
++ PNG_UNUSED(info_ptr)
++
++ return 0;
++}
++#endif /* APNG */
+ #endif /* READ || WRITE */
+Index: png.c
+===================================================================
+--- png.c
++++ png.c
+@@ -776,17 +776,21 @@
+ #else
+ # ifdef __STDC__
+ return PNG_STRING_NEWLINE \
+- "libpng version 1.6.30 - June 28, 2017" PNG_STRING_NEWLINE \
++ "libpng version 1.6.30+apng - June 28, 2017" PNG_STRING_NEWLINE \
+ "Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson" \
+ PNG_STRING_NEWLINE \
+ "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
+ "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
+- PNG_STRING_NEWLINE;
++ PNG_STRING_NEWLINE \
++ "Portions Copyright (c) 2006-2007 Andrew Smith" PNG_STRING_NEWLINE \
++ "Portions Copyright (c) 2008-2017 Max Stepin" PNG_STRING_NEWLINE ;
+ # else
+- return "libpng version 1.6.30 - June 28, 2017\
++ return "libpng version 1.6.30+apng - June 28, 2017\
+ Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson\
+ Copyright (c) 1996-1997 Andreas Dilger\
+- Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
++ Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\
++ Portions Copyright (c) 2006-2007 Andrew Smith\
++ Portions Copyright (c) 2008-2017 Max Stepin";
+ # endif
+ #endif
+ }
+Index: png.h
+===================================================================
+--- png.h
++++ png.h
+@@ -23,6 +23,12 @@
+ * If you modify libpng you may insert additional notices immediately following
+ * this sentence.
+ *
++ * This modified version of libpng code adds animated PNG support and is
++ * released under the libpng license described below. The modifications are
++ * Copyright (c) 2006-2007 Andrew Smith, Copyright (c) 2008-2017 Max Stepin,
++ * and are delimited by "#ifdef PNG_APNG_SUPPORTED / #endif" directives
++ * surrounding them in the modified libpng source files.
++ *
+ * This code is released under the libpng license.
+ *
+ * libpng versions 1.0.7, July 1, 2000 through 1.6.30, June 28, 2017 are
+@@ -309,8 +315,9 @@
+ */
+
+ /* Version information for png.h - this should match the version in png.c */
+-#define PNG_LIBPNG_VER_STRING "1.6.30"
+-#define PNG_HEADER_VERSION_STRING " libpng version 1.6.30 - June 28, 2017\n"
++#define PNG_LIBPNG_VER_STRING "1.6.30+apng"
++#define PNG_HEADER_VERSION_STRING \
++ " libpng version 1.6.30+apng - June 28, 2017\n"
+
+ #define PNG_LIBPNG_VER_SONUM 16
+ #define PNG_LIBPNG_VER_DLLNUM 16
+@@ -361,6 +368,10 @@
+ # include "pnglibconf.h"
+ #endif
+
++#define PNG_APNG_SUPPORTED
++#define PNG_READ_APNG_SUPPORTED
++#define PNG_WRITE_APNG_SUPPORTED
++
+ #ifndef PNG_VERSION_INFO_ONLY
+ /* Machine specific configuration. */
+ # include "pngconf.h"
+@@ -456,6 +467,17 @@
+ * See pngconf.h for base types that vary by machine/system
+ */
+
++#ifdef PNG_APNG_SUPPORTED
++/* dispose_op flags from inside fcTL */
++#define PNG_DISPOSE_OP_NONE 0x00
++#define PNG_DISPOSE_OP_BACKGROUND 0x01
++#define PNG_DISPOSE_OP_PREVIOUS 0x02
++
++/* blend_op flags from inside fcTL */
++#define PNG_BLEND_OP_SOURCE 0x00
++#define PNG_BLEND_OP_OVER 0x01
++#endif /* APNG */
++
+ /* This triggers a compiler error in png.c, if png.c and png.h
+ * do not agree upon the version number.
+ */
+@@ -776,6 +798,10 @@
+ #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
+ #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
+ #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
++#ifdef PNG_APNG_SUPPORTED
++#define PNG_INFO_acTL 0x10000U
++#define PNG_INFO_fcTL 0x20000U
++#endif
+
+ /* This is used for the transformation routines, as some of them
+ * change these values for the row. It also should enable using
+@@ -813,6 +839,10 @@
+ #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+ typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
+ typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
++#ifdef PNG_APNG_SUPPORTED
++typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp,
++ png_uint_32));
++#endif
+
+ /* The following callback receives png_uint_32 row_number, int pass for the
+ * png_bytep data of the row. When transforming an interlaced image the
+@@ -3245,6 +3275,75 @@
+ * END OF HARDWARE AND SOFTWARE OPTIONS
+ ******************************************************************************/
+
++#ifdef PNG_APNG_SUPPORTED
++PNG_EXPORT(246, png_uint_32, png_get_acTL, (png_structp png_ptr,
++ png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays));
++
++PNG_EXPORT(247, png_uint_32, png_set_acTL, (png_structp png_ptr,
++ png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays));
++
++PNG_EXPORT(248, png_uint_32, png_get_num_frames, (png_structp png_ptr,
++ png_infop info_ptr));
++
++PNG_EXPORT(249, png_uint_32, png_get_num_plays, (png_structp png_ptr,
++ png_infop info_ptr));
++
++PNG_EXPORT(250, png_uint_32, png_get_next_frame_fcTL,
++ (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width,
++ png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset,
++ png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op,
++ png_byte *blend_op));
++
++PNG_EXPORT(251, png_uint_32, png_set_next_frame_fcTL,
++ (png_structp png_ptr, png_infop info_ptr, png_uint_32 width,
++ png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset,
++ png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
++ png_byte blend_op));
++
++PNG_EXPORT(252, png_uint_32, png_get_next_frame_width,
++ (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(253, png_uint_32, png_get_next_frame_height,
++ (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(254, png_uint_32, png_get_next_frame_x_offset,
++ (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(255, png_uint_32, png_get_next_frame_y_offset,
++ (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(256, png_uint_16, png_get_next_frame_delay_num,
++ (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(257, png_uint_16, png_get_next_frame_delay_den,
++ (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(258, png_byte, png_get_next_frame_dispose_op,
++ (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(259, png_byte, png_get_next_frame_blend_op,
++ (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(260, png_byte, png_get_first_frame_is_hidden,
++ (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(261, png_uint_32, png_set_first_frame_is_hidden,
++ (png_structp png_ptr, png_infop info_ptr, png_byte is_hidden));
++
++#ifdef PNG_READ_APNG_SUPPORTED
++PNG_EXPORT(262, void, png_read_frame_head, (png_structp png_ptr,
++ png_infop info_ptr));
++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
++PNG_EXPORT(263, void, png_set_progressive_frame_fn, (png_structp png_ptr,
++ png_progressive_frame_ptr frame_info_fn,
++ png_progressive_frame_ptr frame_end_fn));
++#endif /* PROGRESSIVE_READ */
++#endif /* READ_APNG */
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++PNG_EXPORT(264, void, png_write_frame_head, (png_structp png_ptr,
++ png_infop info_ptr, png_bytepp row_pointers,
++ png_uint_32 width, png_uint_32 height,
++ png_uint_32 x_offset, png_uint_32 y_offset,
++ png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
++ png_byte blend_op));
++
++PNG_EXPORT(265, void, png_write_frame_tail, (png_structp png_ptr,
++ png_infop info_ptr));
++#endif /* WRITE_APNG */
++#endif /* APNG */
++
+ /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
+ * defs, and in scripts/symbols.def.
+ */
+@@ -3253,7 +3352,11 @@
+ * one to use is one more than this.)
+ */
+ #ifdef PNG_EXPORT_LAST_ORDINAL
++#ifdef PNG_APNG_SUPPORTED
++ PNG_EXPORT_LAST_ORDINAL(265);
++#else
+ PNG_EXPORT_LAST_ORDINAL(245);
++#endif /* APNG */
+ #endif
+
+ #ifdef __cplusplus
+Index: pngpriv.h
+===================================================================
+--- pngpriv.h
++++ pngpriv.h
+@@ -625,6 +625,10 @@
+ #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
+ /* 0x4000U (unused) */
+ #define PNG_IS_READ_STRUCT 0x8000U /* Else is a write struct */
++#ifdef PNG_APNG_SUPPORTED
++#define PNG_HAVE_acTL 0x10000U
++#define PNG_HAVE_fcTL 0x20000U
++#endif
+
+ /* Flags for the transformations the PNG library does on the image data */
+ #define PNG_BGR 0x0001U
+@@ -860,6 +864,16 @@
+ #define png_tRNS PNG_U32(116, 82, 78, 83)
+ #define png_zTXt PNG_U32(122, 84, 88, 116)
+
++#ifdef PNG_APNG_SUPPORTED
++#define png_acTL PNG_U32( 97, 99, 84, 76)
++#define png_fcTL PNG_U32(102, 99, 84, 76)
++#define png_fdAT PNG_U32(102, 100, 65, 84)
++
++/* For png_struct.apng_flags: */
++#define PNG_FIRST_FRAME_HIDDEN 0x0001U
++#define PNG_APNG_APP 0x0002U
++#endif
++
+ /* The following will work on (signed char*) strings, whereas the get_uint_32
+ * macro will fail on top-bit-set values because of the sign extension.
+ */
+@@ -1598,6 +1612,49 @@
+
+ #endif /* PROGRESSIVE_READ */
+
++#ifdef PNG_APNG_SUPPORTED
++PNG_INTERNAL_FUNCTION(void,png_ensure_fcTL_is_valid,(png_structp png_ptr,
++ png_uint_32 width, png_uint_32 height,
++ png_uint_32 x_offset, png_uint_32 y_offset,
++ png_uint_16 delay_num, png_uint_16 delay_den,
++ png_byte dispose_op, png_byte blend_op),PNG_EMPTY);
++
++#ifdef PNG_READ_APNG_SUPPORTED
++PNG_INTERNAL_FUNCTION(void,png_handle_acTL,(png_structp png_ptr,
++ png_infop info_ptr, png_uint_32 length),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_handle_fcTL,(png_structp png_ptr,
++ png_infop info_ptr, png_uint_32 length),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_handle_fdAT,(png_structp png_ptr,
++ png_infop info_ptr, png_uint_32 length),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_have_info,(png_structp png_ptr,
++ png_infop info_ptr),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_ensure_sequence_number,(png_structp png_ptr,
++ png_uint_32 length),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_read_reset,(png_structp png_ptr),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_read_reinit,(png_structp png_ptr,
++ png_infop info_ptr),PNG_EMPTY);
++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
++PNG_INTERNAL_FUNCTION(void,png_progressive_read_reset,(png_structp png_ptr),
++ PNG_EMPTY);
++#endif /* PROGRESSIVE_READ */
++#endif /* READ_APNG */
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++PNG_INTERNAL_FUNCTION(void,png_write_acTL,(png_structp png_ptr,
++ png_uint_32 num_frames, png_uint_32 num_plays),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_write_fcTL,(png_structp png_ptr,
++ png_uint_32 width, png_uint_32 height,
++ png_uint_32 x_offset, png_uint_32 y_offset,
++ png_uint_16 delay_num, png_uint_16 delay_den,
++ png_byte dispose_op, png_byte blend_op),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_write_fdAT,(png_structp png_ptr,
++ png_const_bytep data, png_size_t length),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_write_reset,(png_structp png_ptr),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_write_reinit,(png_structp png_ptr,
++ png_infop info_ptr, png_uint_32 width, png_uint_32 height),PNG_EMPTY);
++#endif /* WRITE_APNG */
++#endif /* APNG */
++
+ /* Added at libpng version 1.6.0 */
+ #ifdef PNG_GAMMA_SUPPORTED
+ PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
+Index: pnginfo.h
+===================================================================
+--- pnginfo.h
++++ pnginfo.h
+@@ -255,5 +255,18 @@
+ png_bytepp row_pointers; /* the image bits */
+ #endif
+
++#ifdef PNG_APNG_SUPPORTED
++ png_uint_32 num_frames; /* including default image */
++ png_uint_32 num_plays;
++ png_uint_32 next_frame_width;
++ png_uint_32 next_frame_height;
++ png_uint_32 next_frame_x_offset;
++ png_uint_32 next_frame_y_offset;
++ png_uint_16 next_frame_delay_num;
++ png_uint_16 next_frame_delay_den;
++ png_byte next_frame_dispose_op;
++ png_byte next_frame_blend_op;
++#endif
++
+ };
+ #endif /* PNGINFO_H */
+Index: pngstruct.h
+===================================================================
+--- pngstruct.h
++++ pngstruct.h
+@@ -403,6 +403,27 @@
+ png_byte filter_type;
+ #endif
+
++#ifdef PNG_APNG_SUPPORTED
++ png_uint_32 apng_flags;
++ png_uint_32 next_seq_num; /* next fcTL/fdAT chunk sequence number */
++ png_uint_32 first_frame_width;
++ png_uint_32 first_frame_height;
++
++#ifdef PNG_READ_APNG_SUPPORTED
++ png_uint_32 num_frames_read; /* incremented after all image data of */
++ /* a frame is read */
++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
++ png_progressive_frame_ptr frame_info_fn; /* frame info read callback */
++ png_progressive_frame_ptr frame_end_fn; /* frame data read callback */
++#endif
++#endif
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++ png_uint_32 num_frames_to_write;
++ png_uint_32 num_frames_written;
++#endif
++#endif /* APNG */
++
+ /* New members added in libpng-1.2.0 */
+
+ /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
+Index: pngwrite.c
+===================================================================
+--- pngwrite.c
++++ pngwrite.c
+@@ -128,6 +128,10 @@
+ * the application continues writing the PNG. So check the 'invalid'
+ * flag here too.
+ */
++#ifdef PNG_WRITE_APNG_SUPPORTED
++ if ((info_ptr->valid & PNG_INFO_acTL) != 0)
++ png_write_acTL(png_ptr, info_ptr->num_frames, info_ptr->num_plays);
++#endif
+ #ifdef PNG_GAMMA_SUPPORTED
+ # ifdef PNG_WRITE_gAMA_SUPPORTED
+ if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+@@ -360,6 +364,11 @@
+ if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
+ png_error(png_ptr, "No IDATs written into file");
+
++#ifdef PNG_WRITE_APNG_SUPPORTED
++ if (png_ptr->num_frames_written != png_ptr->num_frames_to_write)
++ png_error(png_ptr, "Not enough frames written");
++#endif
++
+ #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ if (png_ptr->num_palette_max > png_ptr->num_palette)
+ png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
+@@ -2382,4 +2391,42 @@
+ }
+ #endif /* SIMPLIFIED_WRITE_STDIO */
+ #endif /* SIMPLIFIED_WRITE */
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++void PNGAPI
++png_write_frame_head(png_structp png_ptr, png_infop info_ptr,
++ png_bytepp row_pointers, png_uint_32 width, png_uint_32 height,
++ png_uint_32 x_offset, png_uint_32 y_offset,
++ png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
++ png_byte blend_op)
++{
++ png_debug(1, "in png_write_frame_head");
++
++ /* there is a chance this has been set after png_write_info was called,
++ * so it would be set but not written. is there a way to be sure? */
++ if ((info_ptr->valid & PNG_INFO_acTL) == 0)
++ png_error(png_ptr, "png_write_frame_head(): acTL not set");
++
++ png_write_reset(png_ptr);
++
++ png_write_reinit(png_ptr, info_ptr, width, height);
++
++ if ((png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) == 0 ||
++ png_ptr->num_frames_written != 0)
++ png_write_fcTL(png_ptr, width, height, x_offset, y_offset,
++ delay_num, delay_den, dispose_op, blend_op);
++
++ PNG_UNUSED(row_pointers)
++}
++
++void PNGAPI
++png_write_frame_tail(png_structp png_ptr, png_infop info_ptr)
++{
++ png_debug(1, "in png_write_frame_tail");
++
++ png_ptr->num_frames_written++;
++
++ PNG_UNUSED(info_ptr)
++}
++#endif /* WRITE_APNG */
+ #endif /* WRITE */
+Index: pngpread.c
+===================================================================
+--- pngpread.c
++++ pngpread.c
+@@ -194,6 +194,89 @@
+
+ chunk_name = png_ptr->chunk_name;
+
++#ifdef PNG_READ_APNG_SUPPORTED
++ if (png_ptr->num_frames_read > 0 &&
++ png_ptr->num_frames_read < info_ptr->num_frames)
++ {
++ if (chunk_name == png_IDAT)
++ {
++ /* Discard trailing IDATs for the first frame */
++ if ((png_ptr->mode & PNG_HAVE_fcTL) != 0 ||
++ png_ptr->num_frames_read > 1)
++ png_error(png_ptr, "out of place IDAT");
++
++ PNG_PUSH_SAVE_BUFFER_IF_FULL
++ png_crc_finish(png_ptr, png_ptr->push_length);
++ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++ }
++
++ else if (chunk_name == png_fdAT)
++ {
++ PNG_PUSH_SAVE_BUFFER_IF_LT(4)
++ png_ensure_sequence_number(png_ptr, 4);
++
++ if ((png_ptr->mode & PNG_HAVE_fcTL) == 0)
++ {
++ /* Discard trailing fdATs for frames other than the first */
++ if (png_ptr->num_frames_read < 2)
++ png_error(png_ptr, "out of place fdAT");
++
++ PNG_PUSH_SAVE_BUFFER_IF_FULL
++ png_crc_finish(png_ptr, png_ptr->push_length);
++ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++ }
++
++ else
++ {
++ /* frame data follows */
++ png_ptr->idat_size = png_ptr->push_length - 4;
++ png_ptr->mode |= PNG_HAVE_IDAT;
++ png_ptr->process_mode = PNG_READ_IDAT_MODE;
++ }
++ }
++
++ else if (chunk_name == png_fcTL)
++ {
++ PNG_PUSH_SAVE_BUFFER_IF_FULL
++ png_read_reset(png_ptr);
++ png_ptr->mode &= ~PNG_HAVE_fcTL;
++
++ png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length);
++
++ if ((png_ptr->mode & PNG_HAVE_fcTL) == 0)
++ png_error(png_ptr, "missing required fcTL chunk");
++
++ png_read_reinit(png_ptr, info_ptr);
++ png_progressive_read_reset(png_ptr);
++
++ if (png_ptr->frame_info_fn != NULL)
++ (*(png_ptr->frame_info_fn))(png_ptr, png_ptr->num_frames_read);
++
++ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++ }
++
++ else if (chunk_name == png_IEND)
++ {
++ PNG_PUSH_SAVE_BUFFER_IF_FULL
++ png_warning(png_ptr, "Number of actual frames fewer than expected");
++ png_crc_finish(png_ptr, png_ptr->push_length);
++ png_ptr->process_mode = PNG_READ_DONE_MODE;
++ png_push_have_end(png_ptr, info_ptr);
++ }
++
++ else
++ {
++ PNG_PUSH_SAVE_BUFFER_IF_FULL
++ png_warning(png_ptr, "Skipped (ignored) a chunk "
++ "between APNG chunks");
++ png_crc_finish(png_ptr, png_ptr->push_length);
++ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++ }
++
++ return;
++ }
++#endif /* READ_APNG */
++
+ if (chunk_name == png_IDAT)
+ {
+ if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
+@@ -260,6 +343,9 @@
+
+ else if (chunk_name == png_IDAT)
+ {
++#ifdef PNG_READ_APNG_SUPPORTED
++ png_have_info(png_ptr, info_ptr);
++#endif
+ png_ptr->idat_size = png_ptr->push_length;
+ png_ptr->process_mode = PNG_READ_IDAT_MODE;
+ png_push_have_info(png_ptr, info_ptr);
+@@ -406,6 +492,20 @@
+ }
+ #endif
+
++#ifdef PNG_READ_APNG_SUPPORTED
++ else if (chunk_name == png_acTL)
++ {
++ PNG_PUSH_SAVE_BUFFER_IF_FULL
++ png_handle_acTL(png_ptr, info_ptr, png_ptr->push_length);
++ }
++
++ else if (chunk_name == png_fcTL)
++ {
++ PNG_PUSH_SAVE_BUFFER_IF_FULL
++ png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length);
++ }
++
++#endif /* READ_APNG */
+ else
+ {
+ PNG_PUSH_SAVE_BUFFER_IF_FULL
+@@ -538,7 +638,11 @@
+ png_byte chunk_tag[4];
+
+ /* TODO: this code can be commoned up with the same code in push_read */
++#ifdef PNG_READ_APNG_SUPPORTED
++ PNG_PUSH_SAVE_BUFFER_IF_LT(12)
++#else
+ PNG_PUSH_SAVE_BUFFER_IF_LT(8)
++#endif
+ png_push_fill_buffer(png_ptr, chunk_length, 4);
+ png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
+ png_reset_crc(png_ptr);
+@@ -546,17 +650,60 @@
+ png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+
++#ifdef PNG_READ_APNG_SUPPORTED
++ if (png_ptr->chunk_name != png_fdAT && png_ptr->num_frames_read > 0)
++ {
++ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) != 0)
++ {
++ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
++ if (png_ptr->frame_end_fn != NULL)
++ (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read);
++ png_ptr->num_frames_read++;
++ return;
++ }
++ else
++ {
++ if (png_ptr->chunk_name == png_IEND)
++ png_error(png_ptr, "Not enough image data");
++ PNG_PUSH_SAVE_BUFFER_IF_FULL
++ png_warning(png_ptr, "Skipping (ignoring) a chunk between "
++ "APNG chunks");
++ png_crc_finish(png_ptr, png_ptr->push_length);
++ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++ return;
++ }
++ }
++ else
++#endif
++#ifdef PNG_READ_APNG_SUPPORTED
++ if (png_ptr->chunk_name != png_IDAT && png_ptr->num_frames_read == 0)
++#else
+ if (png_ptr->chunk_name != png_IDAT)
++#endif
+ {
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+
+ if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+ png_error(png_ptr, "Not enough compressed data");
+
++#ifdef PNG_READ_APNG_SUPPORTED
++ if (png_ptr->frame_end_fn != NULL)
++ (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read);
++ png_ptr->num_frames_read++;
++#endif
++
+ return;
+ }
+
+ png_ptr->idat_size = png_ptr->push_length;
++
++#ifdef PNG_READ_APNG_SUPPORTED
++ if (png_ptr->num_frames_read > 0)
++ {
++ png_ensure_sequence_number(png_ptr, 4);
++ png_ptr->idat_size -= 4;
++ }
++#endif
+ }
+
+ if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0)
+@@ -630,6 +777,16 @@
+ if (!(buffer_length > 0) || buffer == NULL)
+ png_error(png_ptr, "No IDAT data (internal error)");
+
++#ifdef PNG_READ_APNG_SUPPORTED
++ /* If the app is not APNG-aware, decode only the first frame */
++ if ((png_ptr->apng_flags & PNG_APNG_APP) == 0 &&
++ png_ptr->num_frames_read > 0)
++ {
++ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
++ return;
++ }
++#endif
++
+ /* This routine must process all the data it has been given
+ * before returning, calling the row callback as required to
+ * handle the uncompressed results.
+@@ -1084,6 +1241,18 @@
+ png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
+ }
+
++#ifdef PNG_READ_APNG_SUPPORTED
++void PNGAPI
++png_set_progressive_frame_fn(png_structp png_ptr,
++ png_progressive_frame_ptr frame_info_fn,
++ png_progressive_frame_ptr frame_end_fn)
++{
++ png_ptr->frame_info_fn = frame_info_fn;
++ png_ptr->frame_end_fn = frame_end_fn;
++ png_ptr->apng_flags |= PNG_APNG_APP;
++}
++#endif
++
+ png_voidp PNGAPI
+ png_get_progressive_ptr(png_const_structrp png_ptr)
+ {
+Index: pngset.c
+===================================================================
+--- pngset.c
++++ pngset.c
+@@ -241,6 +241,11 @@
+ info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
+
+ info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
++
++#ifdef PNG_APNG_SUPPORTED
++ /* for non-animated png. this may be overwritten from an acTL chunk later */
++ info_ptr->num_frames = 1;
++#endif
+ }
+
+ #ifdef PNG_oFFs_SUPPORTED
+@@ -1111,6 +1116,146 @@
+ }
+ #endif /* sPLT */
+
++#ifdef PNG_APNG_SUPPORTED
++png_uint_32 PNGAPI
++png_set_acTL(png_structp png_ptr, png_infop info_ptr,
++ png_uint_32 num_frames, png_uint_32 num_plays)
++{
++ png_debug1(1, "in %s storage function", "acTL");
++
++ if (png_ptr == NULL || info_ptr == NULL)
++ {
++ png_warning(png_ptr,
++ "Call to png_set_acTL() with NULL png_ptr "
++ "or info_ptr ignored");
++ return (0);
++ }
++ if (num_frames == 0)
++ {
++ png_warning(png_ptr,
++ "Ignoring attempt to set acTL with num_frames zero");
++ return (0);
++ }
++ if (num_frames > PNG_UINT_31_MAX)
++ {
++ png_warning(png_ptr,
++ "Ignoring attempt to set acTL with num_frames > 2^31-1");
++ return (0);
++ }
++ if (num_plays > PNG_UINT_31_MAX)
++ {
++ png_warning(png_ptr,
++ "Ignoring attempt to set acTL with num_plays > 2^31-1");
++ return (0);
++ }
++
++ info_ptr->num_frames = num_frames;
++ info_ptr->num_plays = num_plays;
++
++ info_ptr->valid |= PNG_INFO_acTL;
++
++ return (1);
++}
++
++/* delay_num and delay_den can hold any 16-bit values including zero */
++png_uint_32 PNGAPI
++png_set_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr,
++ png_uint_32 width, png_uint_32 height,
++ png_uint_32 x_offset, png_uint_32 y_offset,
++ png_uint_16 delay_num, png_uint_16 delay_den,
++ png_byte dispose_op, png_byte blend_op)
++{
++ png_debug1(1, "in %s storage function", "fcTL");
++
++ if (png_ptr == NULL || info_ptr == NULL)
++ {
++ png_warning(png_ptr,
++ "Call to png_set_fcTL() with NULL png_ptr or info_ptr "
++ "ignored");
++ return (0);
++ }
++
++ png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset,
++ delay_num, delay_den, dispose_op, blend_op);
++
++ if (blend_op == PNG_BLEND_OP_OVER)
++ {
++ if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0 &&
++ png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) == 0)
++ {
++ png_warning(png_ptr, "PNG_BLEND_OP_OVER is meaningless "
++ "and wasteful for opaque images, ignored");
++ blend_op = PNG_BLEND_OP_SOURCE;
++ }
++ }
++
++ info_ptr->next_frame_width = width;
++ info_ptr->next_frame_height = height;
++ info_ptr->next_frame_x_offset = x_offset;
++ info_ptr->next_frame_y_offset = y_offset;
++ info_ptr->next_frame_delay_num = delay_num;
++ info_ptr->next_frame_delay_den = delay_den;
++ info_ptr->next_frame_dispose_op = dispose_op;
++ info_ptr->next_frame_blend_op = blend_op;
++
++ info_ptr->valid |= PNG_INFO_fcTL;
++
++ return (1);
++}
++
++void /* PRIVATE */
++png_ensure_fcTL_is_valid(png_structp png_ptr,
++ png_uint_32 width, png_uint_32 height,
++ png_uint_32 x_offset, png_uint_32 y_offset,
++ png_uint_16 delay_num, png_uint_16 delay_den,
++ png_byte dispose_op, png_byte blend_op)
++{
++ if (width == 0 || width > PNG_UINT_31_MAX)
++ png_error(png_ptr, "invalid width in fcTL (0 or > 2^31-1)");
++ if (height == 0 || height > PNG_UINT_31_MAX)
++ png_error(png_ptr, "invalid height in fcTL (0 or > 2^31-1)");
++ if (x_offset > PNG_UINT_31_MAX)
++ png_error(png_ptr, "invalid x_offset in fcTL (> 2^31-1)");
++ if (y_offset > PNG_UINT_31_MAX)
++ png_error(png_ptr, "invalid y_offset in fcTL (> 2^31-1)");
++ if (width + x_offset > png_ptr->first_frame_width ||
++ height + y_offset > png_ptr->first_frame_height)
++ png_error(png_ptr, "dimensions of a frame are greater than "
++ "the ones in IHDR");
++
++ if (dispose_op != PNG_DISPOSE_OP_NONE &&
++ dispose_op != PNG_DISPOSE_OP_BACKGROUND &&
++ dispose_op != PNG_DISPOSE_OP_PREVIOUS)
++ png_error(png_ptr, "invalid dispose_op in fcTL");
++
++ if (blend_op != PNG_BLEND_OP_SOURCE &&
++ blend_op != PNG_BLEND_OP_OVER)
++ png_error(png_ptr, "invalid blend_op in fcTL");
++
++ PNG_UNUSED(delay_num)
++ PNG_UNUSED(delay_den)
++}
++
++png_uint_32 PNGAPI
++png_set_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr,
++ png_byte is_hidden)
++{
++ png_debug(1, "in png_first_frame_is_hidden()");
++
++ if (png_ptr == NULL)
++ return 0;
++
++ if (is_hidden != 0)
++ png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;
++ else
++ png_ptr->apng_flags &= ~PNG_FIRST_FRAME_HIDDEN;
++
++ PNG_UNUSED(info_ptr)
++
++ return 1;
++}
++#endif /* APNG */
++
+ #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+ static png_byte
+ check_location(png_const_structrp png_ptr, int location)
+Index: pngrutil.c
+===================================================================
+--- pngrutil.c
++++ pngrutil.c
+@@ -861,6 +861,11 @@
+ filter_type = buf[11];
+ interlace_type = buf[12];
+
++#ifdef PNG_READ_APNG_SUPPORTED
++ png_ptr->first_frame_width = width;
++ png_ptr->first_frame_height = height;
++#endif
++
+ /* Set internal variables */
+ png_ptr->width = width;
+ png_ptr->height = height;
+@@ -2764,6 +2769,180 @@
+ }
+ #endif
+
++#ifdef PNG_READ_APNG_SUPPORTED
++void /* PRIVATE */
++png_handle_acTL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
++{
++ png_byte data[8];
++ png_uint_32 num_frames;
++ png_uint_32 num_plays;
++ png_uint_32 didSet;
++
++ png_debug(1, "in png_handle_acTL");
++
++ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
++ {
++ png_error(png_ptr, "Missing IHDR before acTL");
++ }
++ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
++ {
++ png_warning(png_ptr, "Invalid acTL after IDAT skipped");
++ png_crc_finish(png_ptr, length);
++ return;
++ }
++ else if ((png_ptr->mode & PNG_HAVE_acTL) != 0)
++ {
++ png_warning(png_ptr, "Duplicate acTL skipped");
++ png_crc_finish(png_ptr, length);
++ return;
++ }
++ else if (length != 8)
++ {
++ png_warning(png_ptr, "acTL with invalid length skipped");
++ png_crc_finish(png_ptr, length);
++ return;
++ }
++
++ png_crc_read(png_ptr, data, 8);
++ png_crc_finish(png_ptr, 0);
++
++ num_frames = png_get_uint_31(png_ptr, data);
++ num_plays = png_get_uint_31(png_ptr, data + 4);
++
++ /* the set function will do error checking on num_frames */
++ didSet = png_set_acTL(png_ptr, info_ptr, num_frames, num_plays);
++ if (didSet != 0)
++ png_ptr->mode |= PNG_HAVE_acTL;
++}
++
++void /* PRIVATE */
++png_handle_fcTL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
++{
++ png_byte data[22];
++ png_uint_32 width;
++ png_uint_32 height;
++ png_uint_32 x_offset;
++ png_uint_32 y_offset;
++ png_uint_16 delay_num;
++ png_uint_16 delay_den;
++ png_byte dispose_op;
++ png_byte blend_op;
++
++ png_debug(1, "in png_handle_fcTL");
++
++ png_ensure_sequence_number(png_ptr, length);
++
++ if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
++ {
++ png_error(png_ptr, "Missing IHDR before fcTL");
++ }
++ else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
++ {
++ /* for any frames other then the first this message may be misleading,
++ * but correct. PNG_HAVE_IDAT is unset before the frame head is read
++ * i can't think of a better message */
++ png_warning(png_ptr, "Invalid fcTL after IDAT skipped");
++ png_crc_finish(png_ptr, length-4);
++ return;
++ }
++ else if ((png_ptr->mode & PNG_HAVE_fcTL) != 0)
++ {
++ png_warning(png_ptr, "Duplicate fcTL within one frame skipped");
++ png_crc_finish(png_ptr, length-4);
++ return;
++ }
++ else if (length != 26)
++ {
++ png_warning(png_ptr, "fcTL with invalid length skipped");
++ png_crc_finish(png_ptr, length-4);
++ return;
++ }
++
++ png_crc_read(png_ptr, data, 22);
++ png_crc_finish(png_ptr, 0);
++
++ width = png_get_uint_31(png_ptr, data);
++ height = png_get_uint_31(png_ptr, data + 4);
++ x_offset = png_get_uint_31(png_ptr, data + 8);
++ y_offset = png_get_uint_31(png_ptr, data + 12);
++ delay_num = png_get_uint_16(data + 16);
++ delay_den = png_get_uint_16(data + 18);
++ dispose_op = data[20];
++ blend_op = data[21];
++
++ if (png_ptr->num_frames_read == 0 && (x_offset != 0 || y_offset != 0))
++ {
++ png_warning(png_ptr, "fcTL for the first frame must have zero offset");
++ return;
++ }
++
++ if (info_ptr != NULL)
++ {
++ if (png_ptr->num_frames_read == 0 &&
++ (width != info_ptr->width || height != info_ptr->height))
++ {
++ png_warning(png_ptr, "size in first frame's fcTL must match "
++ "the size in IHDR");
++ return;
++ }
++
++ /* The set function will do more error checking */
++ png_set_next_frame_fcTL(png_ptr, info_ptr, width, height,
++ x_offset, y_offset, delay_num, delay_den,
++ dispose_op, blend_op);
++
++ png_read_reinit(png_ptr, info_ptr);
++
++ png_ptr->mode |= PNG_HAVE_fcTL;
++ }
++}
++
++void /* PRIVATE */
++png_have_info(png_structp png_ptr, png_infop info_ptr)
++{
++ if ((info_ptr->valid & PNG_INFO_acTL) != 0 &&
++ (info_ptr->valid & PNG_INFO_fcTL) == 0)
++ {
++ png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;
++ info_ptr->num_frames++;
++ }
++}
++
++void /* PRIVATE */
++png_handle_fdAT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
++{
++ png_ensure_sequence_number(png_ptr, length);
++
++ /* This function is only called from png_read_end(), png_read_info(),
++ * and png_push_read_chunk() which means that:
++ * - the user doesn't want to read this frame
++ * - or this is an out-of-place fdAT
++ * in either case it is safe to ignore the chunk with a warning */
++ png_warning(png_ptr, "ignoring fdAT chunk");
++ png_crc_finish(png_ptr, length - 4);
++ PNG_UNUSED(info_ptr)
++}
++
++void /* PRIVATE */
++png_ensure_sequence_number(png_structp png_ptr, png_uint_32 length)
++{
++ png_byte data[4];
++ png_uint_32 sequence_number;
++
++ if (length < 4)
++ png_error(png_ptr, "invalid fcTL or fdAT chunk found");
++
++ png_crc_read(png_ptr, data, 4);
++ sequence_number = png_get_uint_31(png_ptr, data);
++
++ if (sequence_number != png_ptr->next_seq_num)
++ png_error(png_ptr, "fcTL or fdAT chunk with out-of-order sequence "
++ "number found");
++
++ png_ptr->next_seq_num++;
++}
++#endif /* READ_APNG */
++
+ #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+ /* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */
+ static int
+@@ -4032,6 +4211,38 @@
+ uInt avail_in;
+ png_bytep buffer;
+
++#ifdef PNG_READ_APNG_SUPPORTED
++ png_uint_32 bytes_to_skip = 0;
++
++ while (png_ptr->idat_size == 0 || bytes_to_skip != 0)
++ {
++ png_crc_finish(png_ptr, bytes_to_skip);
++ bytes_to_skip = 0;
++
++ png_ptr->idat_size = png_read_chunk_header(png_ptr);
++ if (png_ptr->num_frames_read == 0)
++ {
++ if (png_ptr->chunk_name != png_IDAT)
++ png_error(png_ptr, "Not enough image data");
++ }
++ else
++ {
++ if (png_ptr->chunk_name == png_IEND)
++ png_error(png_ptr, "Not enough image data");
++ if (png_ptr->chunk_name != png_fdAT)
++ {
++ png_warning(png_ptr, "Skipped (ignored) a chunk "
++ "between APNG chunks");
++ bytes_to_skip = png_ptr->idat_size;
++ continue;
++ }
++
++ png_ensure_sequence_number(png_ptr, png_ptr->idat_size);
++
++ png_ptr->idat_size -= 4;
++ }
++ }
++#else
+ while (png_ptr->idat_size == 0)
+ {
+ png_crc_finish(png_ptr, 0);
+@@ -4043,6 +4254,7 @@
+ if (png_ptr->chunk_name != png_IDAT)
+ png_error(png_ptr, "Not enough image data");
+ }
++#endif /* READ_APNG */
+
+ avail_in = png_ptr->IDAT_read_size;
+
+@@ -4106,6 +4318,9 @@
+
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
++#ifdef PNG_READ_APNG_SUPPORTED
++ png_ptr->num_frames_read++;
++#endif
+
+ if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0)
+ png_chunk_benign_error(png_ptr, "Extra compressed data");
+@@ -4544,4 +4759,80 @@
+
+ png_ptr->flags |= PNG_FLAG_ROW_INIT;
+ }
++
++#ifdef PNG_READ_APNG_SUPPORTED
++/* This function is to be called after the main IDAT set has been read and
++ * before a new IDAT is read. It resets some parts of png_ptr
++ * to make them usable by the read functions again */
++void /* PRIVATE */
++png_read_reset(png_structp png_ptr)
++{
++ png_ptr->mode &= ~PNG_HAVE_IDAT;
++ png_ptr->mode &= ~PNG_AFTER_IDAT;
++ png_ptr->row_number = 0;
++ png_ptr->pass = 0;
++}
++
++void /* PRIVATE */
++png_read_reinit(png_structp png_ptr, png_infop info_ptr)
++{
++ png_ptr->width = info_ptr->next_frame_width;
++ png_ptr->height = info_ptr->next_frame_height;
++ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->width);
++ png_ptr->info_rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth,
++ png_ptr->width);
++ if (png_ptr->prev_row != NULL)
++ memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
++}
++
++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
++/* same as png_read_reset() but for the progressive reader */
++void /* PRIVATE */
++png_progressive_read_reset(png_structp png_ptr)
++{
++#ifdef PNG_READ_INTERLACING_SUPPORTED
++ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
++
++ /* Start of interlace block */
++ static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
++
++ /* Offset to next interlace block */
++ static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
++
++ /* Start of interlace block in the y direction */
++ static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
++
++ /* Offset to next interlace block in the y direction */
++ static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
++
++ if (png_ptr->interlaced != 0)
++ {
++ if ((png_ptr->transformations & PNG_INTERLACE) == 0)
++ png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
++ png_pass_ystart[0]) / png_pass_yinc[0];
++ 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];
++ }
++ else
++#endif /* READ_INTERLACING */
++ {
++ png_ptr->num_rows = png_ptr->height;
++ png_ptr->iwidth = png_ptr->width;
++ }
++ png_ptr->flags &= ~PNG_FLAG_ZSTREAM_ENDED;
++ if (inflateReset(&(png_ptr->zstream)) != Z_OK)
++ png_error(png_ptr, "inflateReset failed");
++ png_ptr->zstream.avail_in = 0;
++ png_ptr->zstream.next_in = 0;
++ png_ptr->zstream.next_out = png_ptr->row_buf;
++ png_ptr->zstream.avail_out = (uInt)PNG_ROWBYTES(png_ptr->pixel_depth,
++ png_ptr->iwidth) + 1;
++}
++#endif /* PROGRESSIVE_READ */
++#endif /* READ_APNG */
+ #endif /* READ */
+Index: pngwutil.c
+===================================================================
+--- pngwutil.c
++++ pngwutil.c
+@@ -822,6 +822,11 @@
+ /* Write the chunk */
+ png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
+
++#ifdef PNG_WRITE_APNG_SUPPORTED
++ png_ptr->first_frame_width = width;
++ png_ptr->first_frame_height = height;
++#endif
++
+ if ((png_ptr->do_filter) == PNG_NO_FILTERS)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
+@@ -1004,7 +1009,17 @@
+ #endif
+
+ if (size > 0)
++#ifdef PNG_WRITE_APNG_SUPPORTED
++ {
++ if (png_ptr->num_frames_written == 0)
++#endif
+ png_write_complete_chunk(png_ptr, png_IDAT, data, size);
++#ifdef PNG_WRITE_APNG_SUPPORTED
++ else
++ png_write_fdAT(png_ptr, data, size);
++ }
++#endif /* WRITE_APNG */
++
+ png_ptr->mode |= PNG_HAVE_IDAT;
+
+ png_ptr->zstream.next_out = data;
+@@ -1051,7 +1066,17 @@
+ #endif
+
+ if (size > 0)
++#ifdef PNG_WRITE_APNG_SUPPORTED
++ {
++ if (png_ptr->num_frames_written == 0)
++#endif
+ png_write_complete_chunk(png_ptr, png_IDAT, data, size);
++#ifdef PNG_WRITE_APNG_SUPPORTED
++ else
++ png_write_fdAT(png_ptr, data, size);
++ }
++#endif /* WRITE_APNG */
++
+ png_ptr->zstream.avail_out = 0;
+ png_ptr->zstream.next_out = NULL;
+ png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT;
+@@ -1865,6 +1890,82 @@
+ }
+ #endif
+
++#ifdef PNG_WRITE_APNG_SUPPORTED
++void /* PRIVATE */
++png_write_acTL(png_structp png_ptr,
++ png_uint_32 num_frames, png_uint_32 num_plays)
++{
++ png_byte buf[8];
++
++ png_debug(1, "in png_write_acTL");
++
++ png_ptr->num_frames_to_write = num_frames;
++
++ if ((png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) != 0)
++ num_frames--;
++
++ png_save_uint_32(buf, num_frames);
++ png_save_uint_32(buf + 4, num_plays);
++
++ png_write_complete_chunk(png_ptr, png_acTL, buf, (png_size_t)8);
++}
++
++void /* PRIVATE */
++png_write_fcTL(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
++ png_uint_32 x_offset, png_uint_32 y_offset,
++ png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
++ png_byte blend_op)
++{
++ png_byte buf[26];
++
++ png_debug(1, "in png_write_fcTL");
++
++ if (png_ptr->num_frames_written == 0 && (x_offset != 0 || y_offset != 0))
++ png_error(png_ptr, "x and/or y offset for the first frame aren't 0");
++ if (png_ptr->num_frames_written == 0 &&
++ (width != png_ptr->first_frame_width ||
++ height != png_ptr->first_frame_height))
++ png_error(png_ptr, "width and/or height in the first frame's fcTL "
++ "don't match the ones in IHDR");
++
++ /* more error checking */
++ png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset,
++ delay_num, delay_den, dispose_op, blend_op);
++
++ png_save_uint_32(buf, png_ptr->next_seq_num);
++ png_save_uint_32(buf + 4, width);
++ png_save_uint_32(buf + 8, height);
++ png_save_uint_32(buf + 12, x_offset);
++ png_save_uint_32(buf + 16, y_offset);
++ png_save_uint_16(buf + 20, delay_num);
++ png_save_uint_16(buf + 22, delay_den);
++ buf[24] = dispose_op;
++ buf[25] = blend_op;
++
++ png_write_complete_chunk(png_ptr, png_fcTL, buf, (png_size_t)26);
++
++ png_ptr->next_seq_num++;
++}
++
++void /* PRIVATE */
++png_write_fdAT(png_structp png_ptr,
++ png_const_bytep data, png_size_t length)
++{
++ png_byte buf[4];
++
++ png_write_chunk_header(png_ptr, png_fdAT, (png_uint_32)(4 + length));
++
++ png_save_uint_32(buf, png_ptr->next_seq_num);
++ png_write_chunk_data(png_ptr, buf, 4);
++
++ png_write_chunk_data(png_ptr, data, length);
++
++ png_write_chunk_end(png_ptr);
++
++ png_ptr->next_seq_num++;
++}
++#endif /* WRITE_APNG */
++
+ /* Initializes the row writing capability of libpng */
+ void /* PRIVATE */
+ png_write_start_row(png_structrp png_ptr)
+@@ -2759,4 +2860,39 @@
+ }
+ #endif /* WRITE_FLUSH */
+ }
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++void /* PRIVATE */
++png_write_reset(png_structp png_ptr)
++{
++ png_ptr->row_number = 0;
++ png_ptr->pass = 0;
++ png_ptr->mode &= ~PNG_HAVE_IDAT;
++}
++
++void /* PRIVATE */
++png_write_reinit(png_structp png_ptr, png_infop info_ptr,
++ png_uint_32 width, png_uint_32 height)
++{
++ if (png_ptr->num_frames_written == 0 &&
++ (width != png_ptr->first_frame_width ||
++ height != png_ptr->first_frame_height))
++ png_error(png_ptr, "width and/or height in the first frame's fcTL "
++ "don't match the ones in IHDR");
++ if (width > png_ptr->first_frame_width ||
++ height > png_ptr->first_frame_height)
++ png_error(png_ptr, "width and/or height for a frame greater than "
++ "the ones in IHDR");
++
++ png_set_IHDR(png_ptr, info_ptr, width, height,
++ info_ptr->bit_depth, info_ptr->color_type,
++ info_ptr->interlace_type, info_ptr->compression_type,
++ info_ptr->filter_type);
++
++ png_ptr->width = width;
++ png_ptr->height = height;
++ png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
++ png_ptr->usr_width = png_ptr->width;
++}
++#endif /* WRITE_APNG */
+ #endif /* WRITE */
+Index: scripts/symbols.def
+===================================================================
+--- scripts/symbols.def
++++ scripts/symbols.def
+@@ -250,3 +250,23 @@
+ png_get_palette_max @243
+ png_set_option @244
+ png_image_write_to_memory @245
++ png_get_acTL @246
++ png_set_acTL @247
++ png_get_num_frames @248
++ png_get_num_plays @249
++ png_get_next_frame_fcTL @250
++ png_set_next_frame_fcTL @251
++ png_get_next_frame_width @252
++ png_get_next_frame_height @253
++ png_get_next_frame_x_offset @254
++ png_get_next_frame_y_offset @255
++ png_get_next_frame_delay_num @256
++ png_get_next_frame_delay_den @257
++ png_get_next_frame_dispose_op @258
++ png_get_next_frame_blend_op @259
++ png_get_first_frame_is_hidden @260
++ png_set_first_frame_is_hidden @261
++ png_read_frame_head @262
++ png_set_progressive_frame_fn @263
++ png_write_frame_head @264
++ png_write_frame_tail @265
development / ports / opt-arm64.git / commitdiff