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[libpng15] Speed up png_combine_row() for interlaced images. This reduces the

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generality of the code, allowing it to be optimized for Adam7 interlace.  The
masks passed to png_combine_row() are now generated internally, avoiding
some code duplication and localizing the interlace handling somewhat.
This commit is contained in:
Glenn Randers-Pehrson
2011-10-06 21:54:17 -05:00
parent 4daae30174
commit 65c0339b5c
4 changed files with 64 additions and 35 deletions
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31
pngread.c
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@@ -390,11 +390,6 @@ png_start_read_image(png_structp png_ptr)
void PNGAPI
png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
{
#ifdef PNG_READ_INTERLACING_SUPPORTED
PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
0xff};
PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
#endif
int ret;
png_row_info row_info;
@@ -474,8 +469,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
if (png_ptr->row_number & 0x07)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_combine_row(png_ptr, dsp_row, 1/*display*/);
png_read_finish_row(png_ptr);
return;
}
@@ -485,8 +479,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_combine_row(png_ptr, dsp_row, 1/*display*/);
png_read_finish_row(png_ptr);
return;
@@ -497,8 +490,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
if ((png_ptr->row_number & 0x07) != 4)
{
if (dsp_row != NULL && (png_ptr->row_number & 4))
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_combine_row(png_ptr, dsp_row, 1/*display*/);
png_read_finish_row(png_ptr);
return;
@@ -509,8 +501,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
if ((png_ptr->row_number & 3) || png_ptr->width < 3)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_combine_row(png_ptr, dsp_row, 1/*display*/);
png_read_finish_row(png_ptr);
return;
@@ -521,8 +512,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
if ((png_ptr->row_number & 3) != 2)
{
if (dsp_row != NULL && (png_ptr->row_number & 2))
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_combine_row(png_ptr, dsp_row, 1/*display*/);
png_read_finish_row(png_ptr);
return;
@@ -532,8 +522,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
if ((png_ptr->row_number & 1) || png_ptr->width < 2)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_combine_row(png_ptr, dsp_row, 1/*display*/);
png_read_finish_row(png_ptr);
return;
@@ -651,20 +640,20 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
png_ptr->transformations);
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]);
png_combine_row(png_ptr, dsp_row, 1/*display*/);
if (row != NULL)
png_combine_row(png_ptr, row, png_pass_mask[png_ptr->pass]);
png_combine_row(png_ptr, row, 0/*row*/);
}
else
#endif
{
if (row != NULL)
png_combine_row(png_ptr, row, 0xff);
png_combine_row(png_ptr, row, -1/*ignored*/);
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row, 0xff);
png_combine_row(png_ptr, dsp_row, -1/*ignored*/);
}
png_read_finish_row(png_ptr);