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[libpng15] Further optimization of png_combine_row() in the interlaced case.

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This commit is contained in:
John Bowler
2011-10-11 16:01:33 -05:00
committed by Glenn Randers-Pehrson
parent 76b62317b5
commit 4e68aa7e40
4 changed files with 435 additions and 186 deletions
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23
pngvalid.c
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@@ -460,7 +460,13 @@ pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width)
if (p == 0) return 0;
}
return 1; /* Different */
/* Return the index of the changed byte. */
{
png_uint_32 where = 0;
while (pa[where] == pb[where]) ++where;
return 1+where;
}
}
/*************************** BASIC PNG FILE WRITING ***************************/
@@ -4414,6 +4420,7 @@ static void
standard_row_validate(standard_display *dp, png_structp pp,
int iImage, int iDisplay, png_uint_32 y)
{
int where;
png_byte std[STANDARD_ROWMAX];
memset(std, 0xff, sizeof std);
@@ -4430,11 +4437,12 @@ standard_row_validate(standard_display *dp, png_structp pp,
* row bytes are always trashed, so we always do a pixel_cmp here even though
* a memcmp of all cbRow bytes will succeed for the sequential reader.
*/
if (iImage >= 0 && pixel_cmp(std, store_image_row(dp->ps, pp, iImage, y),
dp->bit_width) != 0)
if (iImage >= 0 &&
(where = pixel_cmp(std, store_image_row(dp->ps, pp, iImage, y),
dp->bit_width)) != 0)
{
char msg[64];
sprintf(msg, "PNG image row %d changed", y);
sprintf(msg, "PNG image row %d changed at byte %d", y, where-1);
png_error(pp, msg);
}
@@ -4442,11 +4450,12 @@ standard_row_validate(standard_display *dp, png_structp pp,
* byte at the end of the row if the row is not an exact multiple
* of 8 bits wide.
*/
if (iDisplay >= 0 && pixel_cmp(std, store_image_row(dp->ps, pp, iDisplay, y),
dp->bit_width) != 0)
if (iDisplay >= 0 &&
(where = pixel_cmp(std, store_image_row(dp->ps, pp, iDisplay, y),
dp->bit_width)) != 0)
{
char msg[64];
sprintf(msg, "display row %d changed", y);
sprintf(msg, "display row %d changed at byte %d", y, where-1);
png_error(pp, msg);
}
}