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diff --git a/png.h b/png.h
--- a/png.h
+++ b/png.h
@@ -329,6 +329,10 @@
# 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"
@@ -424,6 +428,17 @@ extern "C" {
* 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.
*/
@@ -745,6 +760,10 @@ typedef png_unknown_chunk * * png_unknow
#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
#define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
+#ifdef PNG_APNG_SUPPORTED
+#define PNG_INFO_acTL 0x20000U
+#define PNG_INFO_fcTL 0x40000U
+#endif
/* This is used for the transformation routines, as some of them
* change these values for the row. It also should enable using
@@ -782,6 +801,10 @@ typedef PNG_CALLBACK(void, *png_write_st
#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
@@ -3230,6 +3253,75 @@ PNG_EXPORT(244, int, png_set_option, (pn
* END OF HARDWARE AND SOFTWARE OPTIONS
******************************************************************************/
+#ifdef PNG_APNG_SUPPORTED
+PNG_EXPORT(248, 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(249, 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(250, png_uint_32, png_get_num_frames, (png_structp png_ptr,
+ png_infop info_ptr));
+
+PNG_EXPORT(251, png_uint_32, png_get_num_plays, (png_structp png_ptr,
+ png_infop info_ptr));
+
+PNG_EXPORT(252, 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(253, 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(254, png_uint_32, png_get_next_frame_width,
+ (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(255, png_uint_32, png_get_next_frame_height,
+ (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(256, png_uint_32, png_get_next_frame_x_offset,
+ (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(257, png_uint_32, png_get_next_frame_y_offset,
+ (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(258, png_uint_16, png_get_next_frame_delay_num,
+ (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(259, png_uint_16, png_get_next_frame_delay_den,
+ (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(260, png_byte, png_get_next_frame_dispose_op,
+ (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(261, png_byte, png_get_next_frame_blend_op,
+ (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(262, png_byte, png_get_first_frame_is_hidden,
+ (png_structp png_ptr, png_infop info_ptr));
+PNG_EXPORT(263, 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(264, void, png_read_frame_head, (png_structp png_ptr,
+ png_infop info_ptr));
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_EXPORT(265, 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(266, 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(267, 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.
*/
@@ -3238,7 +3330,11 @@ PNG_EXPORT(244, int, png_set_option, (pn
* one to use is one more than this.)
*/
#ifdef PNG_EXPORT_LAST_ORDINAL
+#ifdef PNG_APNG_SUPPORTED
+ PNG_EXPORT_LAST_ORDINAL(269);
+#else
PNG_EXPORT_LAST_ORDINAL(249);
+#endif /* APNG */
#endif
#ifdef __cplusplus
diff --git a/pngget.c b/pngget.c
--- a/pngget.c
+++ b/pngget.c
@@ -1264,4 +1264,166 @@ png_get_palette_max(png_const_structp pn
# 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 */
diff --git a/pnginfo.h b/pnginfo.h
--- a/pnginfo.h
+++ b/pnginfo.h
@@ -263,5 +263,18 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
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 */
diff --git a/pngpread.c b/pngpread.c
--- a/pngpread.c
+++ b/pngpread.c
@@ -195,6 +195,89 @@ png_push_read_chunk(png_structrp png_ptr
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)
@@ -261,6 +344,9 @@ png_push_read_chunk(png_structrp png_ptr
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);
@@ -415,6 +501,20 @@ png_push_read_chunk(png_structrp png_ptr
}
#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
@@ -547,7 +647,11 @@ png_push_read_IDAT(png_structrp png_ptr)
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);
@@ -555,17 +659,60 @@ png_push_read_IDAT(png_structrp png_ptr)
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)
@@ -639,6 +786,16 @@ png_process_IDAT_data(png_structrp png_p
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.
@@ -1093,6 +1250,18 @@ png_set_progressive_read_fn(png_structrp
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)
{
diff --git a/pngpriv.h b/pngpriv.h
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -662,6 +662,10 @@
#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
#define PNG_WROTE_eXIf 0x4000U
#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
@@ -898,6 +902,16 @@
#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.
*/
@@ -1683,6 +1697,49 @@ PNG_INTERNAL_FUNCTION(void,png_push_read
#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,
diff --git a/pngread.c b/pngread.c
--- a/pngread.c
+++ b/pngread.c
@@ -161,6 +161,9 @@ png_read_info(png_structrp png_ptr, png_
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;
}
@@ -255,6 +258,17 @@ png_read_info(png_structrp png_ptr, png_
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);
@@ -262,6 +276,72 @@ png_read_info(png_structrp png_ptr, png_
}
#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)
diff --git a/pngrutil.c b/pngrutil.c
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -863,6 +863,11 @@ png_handle_IHDR(png_structrp png_ptr, pn
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;
@@ -2857,6 +2862,180 @@ png_handle_iTXt(png_structrp png_ptr, pn
}
#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
@@ -3162,7 +3341,11 @@ png_check_chunk_length(png_const_structr
if (PNG_USER_CHUNK_MALLOC_MAX < limit)
limit = PNG_USER_CHUNK_MALLOC_MAX;
# endif
+#ifdef PNG_READ_APNG_SUPPORTED
+ if (png_ptr->chunk_name == png_IDAT || png_ptr->chunk_name == png_fdAT)
+#else
if (png_ptr->chunk_name == png_IDAT)
+#endif
{
png_alloc_size_t idat_limit = PNG_UINT_31_MAX;
size_t row_factor =
@@ -4166,6 +4349,38 @@ png_read_IDAT_data(png_structrp png_ptr,
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);
@@ -4177,6 +4392,7 @@ png_read_IDAT_data(png_structrp png_ptr,
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;
@@ -4240,6 +4456,9 @@ png_read_IDAT_data(png_structrp png_ptr,
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");
@@ -4677,4 +4896,80 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED
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 */
diff --git a/pngset.c b/pngset.c
--- a/pngset.c
+++ b/pngset.c
@@ -280,6 +280,11 @@ png_set_IHDR(png_const_structrp png_ptr,
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
@@ -1151,6 +1156,146 @@ png_set_sPLT(png_const_structrp png_ptr,
}
#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)
diff --git a/pngstruct.h b/pngstruct.h
--- a/pngstruct.h
+++ b/pngstruct.h
@@ -399,6 +399,27 @@ struct png_struct_def
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 */
diff --git a/pngwrite.c b/pngwrite.c
--- a/pngwrite.c
+++ b/pngwrite.c
@@ -128,6 +128,10 @@ png_write_info_before_PLTE(png_structrp
* 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 &&
@@ -368,6 +372,11 @@ png_write_end(png_structrp png_ptr, png_
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->color_type == PNG_COLOR_TYPE_PALETTE &&
png_ptr->num_palette_max >= png_ptr->num_palette)
@@ -2415,4 +2424,42 @@ png_image_write_to_file(png_imagep image
}
#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 */
diff --git a/pngwutil.c b/pngwutil.c
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -823,6 +823,11 @@ png_write_IHDR(png_structrp png_ptr, png
/* Write the chunk */
png_write_complete_chunk(png_ptr, png_IHDR, buf, 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)
{
#ifdef PNG_WRITE_FILTER_SUPPORTED
@@ -1009,7 +1014,17 @@ png_compress_IDAT(png_structrp png_ptr,
#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;
@@ -1056,7 +1071,17 @@ png_compress_IDAT(png_structrp png_ptr,
#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;
@@ -1891,6 +1916,82 @@ png_write_tIME(png_structrp png_ptr, png
}
#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)
@@ -2784,4 +2885,39 @@ png_write_filtered_row(png_structrp png_
}
#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 */