Update libpng from 1.6.3 to 1.6.10
Change-Id: I76e81e7fd267d15991cd342c5caeb2fe77964ebf
diff --git a/pngrtran.c b/pngrtran.c
index e378ceb..5395396 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -1,8 +1,8 @@
/* pngrtran.c - transforms the data in a row for PNG readers
*
- * Last changed in libpng 1.6.2 [April 25, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Copyright (c) 1998-2014 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
@@ -1116,19 +1116,25 @@
/* Ignore if all the entries are opaque (unlikely!) */
for (i=0; i<png_ptr->num_trans; ++i)
+ {
if (png_ptr->trans_alpha[i] == 255)
continue;
else if (png_ptr->trans_alpha[i] == 0)
input_has_transparency = 1;
else
+ {
+ input_has_transparency = 1;
input_has_alpha = 1;
+ break;
+ }
+ }
}
/* If no alpha we can optimize. */
if (!input_has_alpha)
{
/* Any alpha means background and associative alpha processing is
- * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA
+ * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
* and ENCODE_ALPHA are irrelevant.
*/
png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
@@ -1193,7 +1199,7 @@
if (!input_has_alpha)
{
/* Any alpha means background and associative alpha processing is
- * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA
+ * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
* and ENCODE_ALPHA are irrelevant.
*/
# ifdef PNG_READ_ALPHA_MODE_SUPPORTED
@@ -1357,12 +1363,12 @@
* 12) PNG_EXPAND_16
* 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY
* 14) PNG_INVERT_MONO
- * 15) PNG_SHIFT
- * 16) PNG_PACK
- * 17) PNG_BGR
- * 18) PNG_PACKSWAP
- * 19) PNG_FILLER (includes PNG_ADD_ALPHA)
- * 20) PNG_INVERT_ALPHA
+ * 15) PNG_INVERT_ALPHA
+ * 16) PNG_SHIFT
+ * 17) PNG_PACK
+ * 18) PNG_BGR
+ * 19) PNG_PACKSWAP
+ * 20) PNG_FILLER (includes PNG_ADD_ALPHA)
* 21) PNG_SWAP_ALPHA
* 22) PNG_SWAP_BYTES
* 23) PNG_USER_TRANSFORM [must be last]
@@ -1878,31 +1884,34 @@
* the number of significant bits is 0 then no shift is done (this is an
* error condition which is silently ignored.)
*/
- if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
- {
- int component = png_ptr->palette[i].red;
+ if (shift > 0 && shift < 8)
+ for (i=0; i<istop; ++i)
+ {
+ int component = png_ptr->palette[i].red;
- component >>= shift;
- png_ptr->palette[i].red = (png_byte)component;
- }
+ component >>= shift;
+ png_ptr->palette[i].red = (png_byte)component;
+ }
shift = 8 - png_ptr->sig_bit.green;
- if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
- {
- int component = png_ptr->palette[i].green;
+ if (shift > 0 && shift < 8)
+ for (i=0; i<istop; ++i)
+ {
+ int component = png_ptr->palette[i].green;
- component >>= shift;
- png_ptr->palette[i].green = (png_byte)component;
- }
+ component >>= shift;
+ png_ptr->palette[i].green = (png_byte)component;
+ }
shift = 8 - png_ptr->sig_bit.blue;
- if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
- {
- int component = png_ptr->palette[i].blue;
+ if (shift > 0 && shift < 8)
+ for (i=0; i<istop; ++i)
+ {
+ int component = png_ptr->palette[i].blue;
- component >>= shift;
- png_ptr->palette[i].blue = (png_byte)component;
- }
+ component >>= shift;
+ png_ptr->palette[i].blue = (png_byte)component;
+ }
}
#endif /* PNG_READ_SHIFT_SUPPORTED */
}
@@ -1933,6 +1942,9 @@
info_ptr->bit_depth = 8;
info_ptr->num_trans = 0;
+
+ if (png_ptr->palette == NULL)
+ png_error (png_ptr, "Palette is NULL in indexed image");
}
else
{
@@ -2111,303 +2123,6 @@
#endif
}
-/* Transform the row. The order of transformations is significant,
- * and is very touchy. If you add a transformation, take care to
- * decide how it fits in with the other transformations here.
- */
-void /* PRIVATE */
-png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
-{
- png_debug(1, "in png_do_read_transformations");
-
- if (png_ptr->row_buf == NULL)
- {
- /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this
- * error is incredibly rare and incredibly easy to debug without this
- * information.
- */
- png_error(png_ptr, "NULL row buffer");
- }
-
- /* The following is debugging; prior to 1.5.4 the code was never compiled in;
- * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
- * PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for
- * all transformations, however in practice the ROW_INIT always gets done on
- * demand, if necessary.
- */
- if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
- !(png_ptr->flags & PNG_FLAG_ROW_INIT))
- {
- /* Application has failed to call either png_read_start_image() or
- * png_read_update_info() after setting transforms that expand pixels.
- * This check added to libpng-1.2.19 (but not enabled until 1.5.4).
- */
- png_error(png_ptr, "Uninitialized row");
- }
-
-#ifdef PNG_READ_EXPAND_SUPPORTED
- if (png_ptr->transformations & PNG_EXPAND)
- {
- if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_do_expand_palette(row_info, png_ptr->row_buf + 1,
- png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
- }
-
- else
- {
- if (png_ptr->num_trans &&
- (png_ptr->transformations & PNG_EXPAND_tRNS))
- png_do_expand(row_info, png_ptr->row_buf + 1,
- &(png_ptr->trans_color));
-
- else
- png_do_expand(row_info, png_ptr->row_buf + 1,
- NULL);
- }
- }
-#endif
-
-#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
- if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
- !(png_ptr->transformations & PNG_COMPOSE) &&
- (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
- row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
- png_do_strip_channel(row_info, png_ptr->row_buf + 1,
- 0 /* at_start == false, because SWAP_ALPHA happens later */);
-#endif
-
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
- if (png_ptr->transformations & PNG_RGB_TO_GRAY)
- {
- int rgb_error =
- png_do_rgb_to_gray(png_ptr, row_info,
- png_ptr->row_buf + 1);
-
- if (rgb_error)
- {
- png_ptr->rgb_to_gray_status=1;
- if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
- PNG_RGB_TO_GRAY_WARN)
- png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
-
- if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
- PNG_RGB_TO_GRAY_ERR)
- png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
- }
- }
-#endif
-
-/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
- *
- * In most cases, the "simple transparency" should be done prior to doing
- * gray-to-RGB, or you will have to test 3x as many bytes to check if a
- * pixel is transparent. You would also need to make sure that the
- * transparency information is upgraded to RGB.
- *
- * To summarize, the current flow is:
- * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
- * with background "in place" if transparent,
- * convert to RGB if necessary
- * - Gray + alpha -> composite with gray background and remove alpha bytes,
- * convert to RGB if necessary
- *
- * To support RGB backgrounds for gray images we need:
- * - Gray + simple transparency -> convert to RGB + simple transparency,
- * compare 3 or 6 bytes and composite with
- * background "in place" if transparent
- * (3x compare/pixel compared to doing
- * composite with gray bkgrnd)
- * - Gray + alpha -> convert to RGB + alpha, composite with background and
- * remove alpha bytes (3x float
- * operations/pixel compared with composite
- * on gray background)
- *
- * Greg's change will do this. The reason it wasn't done before is for
- * performance, as this increases the per-pixel operations. If we would check
- * in advance if the background was gray or RGB, and position the gray-to-RGB
- * transform appropriately, then it would save a lot of work/time.
- */
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
- /* If gray -> RGB, do so now only if background is non-gray; else do later
- * for performance reasons
- */
- if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
- !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
- png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
- defined(PNG_READ_ALPHA_MODE_SUPPORTED)
- if (png_ptr->transformations & PNG_COMPOSE)
- png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr);
-#endif
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
- if ((png_ptr->transformations & PNG_GAMMA) &&
-#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
- /* Because RGB_TO_GRAY does the gamma transform. */
- !(png_ptr->transformations & PNG_RGB_TO_GRAY) &&
-#endif
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
- defined(PNG_READ_ALPHA_MODE_SUPPORTED)
- /* Because PNG_COMPOSE does the gamma transform if there is something to
- * do (if there is an alpha channel or transparency.)
- */
- !((png_ptr->transformations & PNG_COMPOSE) &&
- ((png_ptr->num_trans != 0) ||
- (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
-#endif
- /* Because png_init_read_transformations transforms the palette, unless
- * RGB_TO_GRAY will do the transform.
- */
- (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
- png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr);
-#endif
-
-#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
- if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
- (png_ptr->transformations & PNG_COMPOSE) &&
- (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
- row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
- png_do_strip_channel(row_info, png_ptr->row_buf + 1,
- 0 /* at_start == false, because SWAP_ALPHA happens later */);
-#endif
-
-#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
- if ((png_ptr->transformations & PNG_ENCODE_ALPHA) &&
- (row_info->color_type & PNG_COLOR_MASK_ALPHA))
- png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr);
-#endif
-
-#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
- if (png_ptr->transformations & PNG_SCALE_16_TO_8)
- png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
- /* There is no harm in doing both of these because only one has any effect,
- * by putting the 'scale' option first if the app asks for scale (either by
- * calling the API or in a TRANSFORM flag) this is what happens.
- */
- if (png_ptr->transformations & PNG_16_TO_8)
- png_do_chop(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_QUANTIZE_SUPPORTED
- if (png_ptr->transformations & PNG_QUANTIZE)
- {
- png_do_quantize(row_info, png_ptr->row_buf + 1,
- png_ptr->palette_lookup, png_ptr->quantize_index);
-
- if (row_info->rowbytes == 0)
- png_error(png_ptr, "png_do_quantize returned rowbytes=0");
- }
-#endif /* PNG_READ_QUANTIZE_SUPPORTED */
-
-#ifdef PNG_READ_EXPAND_16_SUPPORTED
- /* Do the expansion now, after all the arithmetic has been done. Notice
- * that previous transformations can handle the PNG_EXPAND_16 flag if this
- * is efficient (particularly true in the case of gamma correction, where
- * better accuracy results faster!)
- */
- if (png_ptr->transformations & PNG_EXPAND_16)
- png_do_expand_16(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
- /* NOTE: moved here in 1.5.4 (from much later in this list.) */
- if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
- (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
- png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_INVERT_SUPPORTED
- if (png_ptr->transformations & PNG_INVERT_MONO)
- png_do_invert(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_SHIFT_SUPPORTED
- if (png_ptr->transformations & PNG_SHIFT)
- png_do_unshift(row_info, png_ptr->row_buf + 1,
- &(png_ptr->shift));
-#endif
-
-#ifdef PNG_READ_PACK_SUPPORTED
- if (png_ptr->transformations & PNG_PACK)
- png_do_unpack(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
- /* Added at libpng-1.5.10 */
- if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
- png_ptr->num_palette_max >= 0)
- png_do_check_palette_indexes(png_ptr, row_info);
-#endif
-
-#ifdef PNG_READ_BGR_SUPPORTED
- if (png_ptr->transformations & PNG_BGR)
- png_do_bgr(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_PACKSWAP_SUPPORTED
- if (png_ptr->transformations & PNG_PACKSWAP)
- png_do_packswap(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_FILLER_SUPPORTED
- if (png_ptr->transformations & PNG_FILLER)
- png_do_read_filler(row_info, png_ptr->row_buf + 1,
- (png_uint_32)png_ptr->filler, png_ptr->flags);
-#endif
-
-#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
- if (png_ptr->transformations & PNG_INVERT_ALPHA)
- png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
- if (png_ptr->transformations & PNG_SWAP_ALPHA)
- png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);
-#endif
-
-#ifdef PNG_READ_16BIT_SUPPORTED
-#ifdef PNG_READ_SWAP_SUPPORTED
- if (png_ptr->transformations & PNG_SWAP_BYTES)
- png_do_swap(row_info, png_ptr->row_buf + 1);
-#endif
-#endif
-
-#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
- if (png_ptr->transformations & PNG_USER_TRANSFORM)
- {
- if (png_ptr->read_user_transform_fn != NULL)
- (*(png_ptr->read_user_transform_fn)) /* User read transform function */
- (png_ptr, /* png_ptr */
- row_info, /* row_info: */
- /* png_uint_32 width; width of row */
- /* png_size_t rowbytes; number of bytes in row */
- /* png_byte color_type; color type of pixels */
- /* png_byte bit_depth; bit depth of samples */
- /* png_byte channels; number of channels (1-4) */
- /* png_byte pixel_depth; bits per pixel (depth*channels) */
- png_ptr->row_buf + 1); /* start of pixel data for row */
-#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
- if (png_ptr->user_transform_depth)
- row_info->bit_depth = png_ptr->user_transform_depth;
-
- if (png_ptr->user_transform_channels)
- row_info->channels = png_ptr->user_transform_channels;
-#endif
- row_info->pixel_depth = (png_byte)(row_info->bit_depth *
- row_info->channels);
-
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width);
- }
-#endif
-}
-
#ifdef PNG_READ_PACK_SUPPORTED
/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
* without changing the actual values. Thus, if you had a row with
@@ -2415,7 +2130,7 @@
* the numbers 0 or 1. If you would rather they contain 0 and 255, use
* png_do_shift() after this.
*/
-void /* PRIVATE */
+static void
png_do_unpack(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_unpack");
@@ -2513,7 +2228,7 @@
* a row of bit depth 8, but only 5 are significant, this will shift
* the values back to 0 through 31.
*/
-void /* PRIVATE */
+static void
png_do_unshift(png_row_infop row_info, png_bytep row,
png_const_color_8p sig_bits)
{
@@ -2652,7 +2367,7 @@
#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
/* Scale rows of bit depth 16 down to 8 accurately */
-void /* PRIVATE */
+static void
png_do_scale_16_to_8(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_scale_16_to_8");
@@ -2710,7 +2425,7 @@
#endif
#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
-void /* PRIVATE */
+static void
/* Simply discard the low byte. This was the default behavior prior
* to libpng-1.5.4.
*/
@@ -2738,7 +2453,7 @@
#endif
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
-void /* PRIVATE */
+static void
png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_read_swap_alpha");
@@ -2835,7 +2550,7 @@
#endif
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
-void /* PRIVATE */
+static void
png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
{
png_uint_32 row_width;
@@ -2937,7 +2652,7 @@
#ifdef PNG_READ_FILLER_SUPPORTED
/* Add filler channel if we have RGB color */
-void /* PRIVATE */
+static void
png_do_read_filler(png_row_infop row_info, png_bytep row,
png_uint_32 filler, png_uint_32 flags)
{
@@ -3124,7 +2839,7 @@
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
/* Expand grayscale files to RGB, with or without alpha */
-void /* PRIVATE */
+static void
png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
{
png_uint_32 i;
@@ -3263,7 +2978,7 @@
* calculated to make the sum 32768. This will result in different rounding
* to that used above.
*/
-int /* PRIVATE */
+static int
png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
{
@@ -3457,73 +3172,14 @@
return rgb_error;
}
#endif
-#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
-#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
-/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth
- * large of png_color. This lets grayscale images be treated as
- * paletted. Most useful for gamma correction and simplification
- * of code. This API is not used internally.
- */
-void PNGAPI
-png_build_grayscale_palette(int bit_depth, png_colorp palette)
-{
- int num_palette;
- int color_inc;
- int i;
- int v;
-
- png_debug(1, "in png_do_build_grayscale_palette");
-
- if (palette == NULL)
- return;
-
- switch (bit_depth)
- {
- case 1:
- num_palette = 2;
- color_inc = 0xff;
- break;
-
- case 2:
- num_palette = 4;
- color_inc = 0x55;
- break;
-
- case 4:
- num_palette = 16;
- color_inc = 0x11;
- break;
-
- case 8:
- num_palette = 256;
- color_inc = 1;
- break;
-
- default:
- num_palette = 0;
- color_inc = 0;
- break;
- }
-
- for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
- {
- palette[i].red = (png_byte)v;
- palette[i].green = (png_byte)v;
- palette[i].blue = (png_byte)v;
- }
-}
-#endif
-
-
-#ifdef PNG_READ_TRANSFORMS_SUPPORTED
#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
defined(PNG_READ_ALPHA_MODE_SUPPORTED)
/* Replace any alpha or transparency with the supplied background color.
* "background" is already in the screen gamma, while "background_1" is
* at a gamma of 1.0. Paletted files have already been taken care of.
*/
-void /* PRIVATE */
+static void
png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
{
#ifdef PNG_READ_GAMMA_SUPPORTED
@@ -4263,7 +3919,7 @@
* is 16, use gamma_16_table and gamma_shift. Build these with
* build_gamma_table().
*/
-void /* PRIVATE */
+static void
png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
{
png_const_bytep gamma_table = png_ptr->gamma_table;
@@ -4464,7 +4120,7 @@
* linear.) Called only with color types that have an alpha channel. Needs the
* from_1 tables.
*/
-void /* PRIVATE */
+static void
png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
{
png_uint_32 row_width = row_info->width;
@@ -4530,7 +4186,7 @@
/* Expands a palette row to an RGB or RGBA row depending
* upon whether you supply trans and num_trans.
*/
-void /* PRIVATE */
+static void
png_do_expand_palette(png_row_infop row_info, png_bytep row,
png_const_colorp palette, png_const_bytep trans_alpha, int num_trans)
{
@@ -4683,7 +4339,7 @@
/* If the bit depth < 8, it is expanded to 8. Also, if the already
* expanded transparency value is supplied, an alpha channel is built.
*/
-void /* PRIVATE */
+static void
png_do_expand(png_row_infop row_info, png_bytep row,
png_const_color_16p trans_color)
{
@@ -4913,7 +4569,7 @@
/* If the bit depth is 8 and the color type is not a palette type expand the
* whole row to 16 bits. Has no effect otherwise.
*/
-void /* PRIVATE */
+static void
png_do_expand_16(png_row_infop row_info, png_bytep row)
{
if (row_info->bit_depth == 8 &&
@@ -4941,7 +4597,7 @@
#endif
#ifdef PNG_READ_QUANTIZE_SUPPORTED
-void /* PRIVATE */
+static void
png_do_quantize(png_row_infop row_info, png_bytep row,
png_const_bytep palette_lookup, png_const_bytep quantize_lookup)
{
@@ -5033,69 +4689,303 @@
}
}
#endif /* PNG_READ_QUANTIZE_SUPPORTED */
-#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
-#ifdef PNG_MNG_FEATURES_SUPPORTED
-/* Undoes intrapixel differencing */
+/* Transform the row. The order of transformations is significant,
+ * and is very touchy. If you add a transformation, take care to
+ * decide how it fits in with the other transformations here.
+ */
void /* PRIVATE */
-png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
+png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
{
- png_debug(1, "in png_do_read_intrapixel");
+ png_debug(1, "in png_do_read_transformations");
- if (
- (row_info->color_type & PNG_COLOR_MASK_COLOR))
+ if (png_ptr->row_buf == NULL)
{
- int bytes_per_pixel;
- png_uint_32 row_width = row_info->width;
+ /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this
+ * error is incredibly rare and incredibly easy to debug without this
+ * information.
+ */
+ png_error(png_ptr, "NULL row buffer");
+ }
- if (row_info->bit_depth == 8)
+ /* The following is debugging; prior to 1.5.4 the code was never compiled in;
+ * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
+ * PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for
+ * all transformations, however in practice the ROW_INIT always gets done on
+ * demand, if necessary.
+ */
+ if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
+ !(png_ptr->flags & PNG_FLAG_ROW_INIT))
+ {
+ /* Application has failed to call either png_read_start_image() or
+ * png_read_update_info() after setting transforms that expand pixels.
+ * This check added to libpng-1.2.19 (but not enabled until 1.5.4).
+ */
+ png_error(png_ptr, "Uninitialized row");
+ }
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+ if (png_ptr->transformations & PNG_EXPAND)
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
{
- png_bytep rp;
- png_uint_32 i;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- bytes_per_pixel = 3;
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- bytes_per_pixel = 4;
-
- else
- return;
-
- for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
- {
- *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff);
- *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff);
- }
+ png_do_expand_palette(row_info, png_ptr->row_buf + 1,
+ png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
}
- else if (row_info->bit_depth == 16)
+
+ else
{
- png_bytep rp;
- png_uint_32 i;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- bytes_per_pixel = 6;
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- bytes_per_pixel = 8;
+ if (png_ptr->num_trans &&
+ (png_ptr->transformations & PNG_EXPAND_tRNS))
+ png_do_expand(row_info, png_ptr->row_buf + 1,
+ &(png_ptr->trans_color));
else
- return;
-
- for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
- {
- png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
- png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
- png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
- png_uint_32 red = (s0 + s1 + 65536) & 0xffff;
- png_uint_32 blue = (s2 + s1 + 65536) & 0xffff;
- *(rp ) = (png_byte)((red >> 8) & 0xff);
- *(rp + 1) = (png_byte)(red & 0xff);
- *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
- *(rp + 5) = (png_byte)(blue & 0xff);
- }
+ png_do_expand(row_info, png_ptr->row_buf + 1,
+ NULL);
}
}
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
+ !(png_ptr->transformations & PNG_COMPOSE) &&
+ (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+ png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+ 0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+ {
+ int rgb_error =
+ png_do_rgb_to_gray(png_ptr, row_info,
+ png_ptr->row_buf + 1);
+
+ if (rgb_error)
+ {
+ png_ptr->rgb_to_gray_status=1;
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ PNG_RGB_TO_GRAY_WARN)
+ png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ PNG_RGB_TO_GRAY_ERR)
+ png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+ }
+ }
+#endif
+
+/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
+ *
+ * In most cases, the "simple transparency" should be done prior to doing
+ * gray-to-RGB, or you will have to test 3x as many bytes to check if a
+ * pixel is transparent. You would also need to make sure that the
+ * transparency information is upgraded to RGB.
+ *
+ * To summarize, the current flow is:
+ * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
+ * with background "in place" if transparent,
+ * convert to RGB if necessary
+ * - Gray + alpha -> composite with gray background and remove alpha bytes,
+ * convert to RGB if necessary
+ *
+ * To support RGB backgrounds for gray images we need:
+ * - Gray + simple transparency -> convert to RGB + simple transparency,
+ * compare 3 or 6 bytes and composite with
+ * background "in place" if transparent
+ * (3x compare/pixel compared to doing
+ * composite with gray bkgrnd)
+ * - Gray + alpha -> convert to RGB + alpha, composite with background and
+ * remove alpha bytes (3x float
+ * operations/pixel compared with composite
+ * on gray background)
+ *
+ * Greg's change will do this. The reason it wasn't done before is for
+ * performance, as this increases the per-pixel operations. If we would check
+ * in advance if the background was gray or RGB, and position the gray-to-RGB
+ * transform appropriately, then it would save a lot of work/time.
+ */
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* If gray -> RGB, do so now only if background is non-gray; else do later
+ * for performance reasons
+ */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+ !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+ png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+ if (png_ptr->transformations & PNG_COMPOSE)
+ png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+ if ((png_ptr->transformations & PNG_GAMMA) &&
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+ /* Because RGB_TO_GRAY does the gamma transform. */
+ !(png_ptr->transformations & PNG_RGB_TO_GRAY) &&
+#endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+ defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+ /* Because PNG_COMPOSE does the gamma transform if there is something to
+ * do (if there is an alpha channel or transparency.)
+ */
+ !((png_ptr->transformations & PNG_COMPOSE) &&
+ ((png_ptr->num_trans != 0) ||
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
+#endif
+ /* Because png_init_read_transformations transforms the palette, unless
+ * RGB_TO_GRAY will do the transform.
+ */
+ (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
+ png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+ if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
+ (png_ptr->transformations & PNG_COMPOSE) &&
+ (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+ png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+ 0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+ if ((png_ptr->transformations & PNG_ENCODE_ALPHA) &&
+ (row_info->color_type & PNG_COLOR_MASK_ALPHA))
+ png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+ if (png_ptr->transformations & PNG_SCALE_16_TO_8)
+ png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+ /* There is no harm in doing both of these because only one has any effect,
+ * by putting the 'scale' option first if the app asks for scale (either by
+ * calling the API or in a TRANSFORM flag) this is what happens.
+ */
+ if (png_ptr->transformations & PNG_16_TO_8)
+ png_do_chop(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ if (png_ptr->transformations & PNG_QUANTIZE)
+ {
+ png_do_quantize(row_info, png_ptr->row_buf + 1,
+ png_ptr->palette_lookup, png_ptr->quantize_index);
+
+ if (row_info->rowbytes == 0)
+ png_error(png_ptr, "png_do_quantize returned rowbytes=0");
+ }
+#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+ /* Do the expansion now, after all the arithmetic has been done. Notice
+ * that previous transformations can handle the PNG_EXPAND_16 flag if this
+ * is efficient (particularly true in the case of gamma correction, where
+ * better accuracy results faster!)
+ */
+ if (png_ptr->transformations & PNG_EXPAND_16)
+ png_do_expand_16(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* NOTE: moved here in 1.5.4 (from much later in this list.) */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+ (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+ png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_INVERT_SUPPORTED
+ if (png_ptr->transformations & PNG_INVERT_MONO)
+ png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+ if (png_ptr->transformations & PNG_INVERT_ALPHA)
+ png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+ if (png_ptr->transformations & PNG_SHIFT)
+ png_do_unshift(row_info, png_ptr->row_buf + 1,
+ &(png_ptr->shift));
+#endif
+
+#ifdef PNG_READ_PACK_SUPPORTED
+ if (png_ptr->transformations & PNG_PACK)
+ png_do_unpack(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ /* Added at libpng-1.5.10 */
+ if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
+ png_ptr->num_palette_max >= 0)
+ png_do_check_palette_indexes(png_ptr, row_info);
+#endif
+
+#ifdef PNG_READ_BGR_SUPPORTED
+ if (png_ptr->transformations & PNG_BGR)
+ png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+ if (png_ptr->transformations & PNG_FILLER)
+ png_do_read_filler(row_info, png_ptr->row_buf + 1,
+ (png_uint_32)png_ptr->filler, png_ptr->flags);
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+ if (png_ptr->transformations & PNG_SWAP_ALPHA)
+ png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+#ifdef PNG_READ_SWAP_SUPPORTED
+ if (png_ptr->transformations & PNG_SWAP_BYTES)
+ png_do_swap(row_info, png_ptr->row_buf + 1);
+#endif
+#endif
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)
+ {
+ if (png_ptr->read_user_transform_fn != NULL)
+ (*(png_ptr->read_user_transform_fn)) /* User read transform function */
+ (png_ptr, /* png_ptr */
+ row_info, /* row_info: */
+ /* png_uint_32 width; width of row */
+ /* png_size_t rowbytes; number of bytes in row */
+ /* png_byte color_type; color type of pixels */
+ /* png_byte bit_depth; bit depth of samples */
+ /* png_byte channels; number of channels (1-4) */
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */
+ png_ptr->row_buf + 1); /* start of pixel data for row */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+ if (png_ptr->user_transform_depth)
+ row_info->bit_depth = png_ptr->user_transform_depth;
+
+ if (png_ptr->user_transform_channels)
+ row_info->channels = png_ptr->user_transform_channels;
+#endif
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth *
+ row_info->channels);
+
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width);
+ }
+#endif
}
-#endif /* PNG_MNG_FEATURES_SUPPORTED */
+
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
#endif /* PNG_READ_SUPPORTED */