mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
48 lines
1.6 KiB
48 lines
1.6 KiB
/* |
|
* PNG image format |
|
* Copyright (c) 2008 Loren Merrit <lorenm@u.washington.edu> |
|
* |
|
* This file is part of Libav. |
|
* |
|
* Libav is free software; you can redistribute it and/or |
|
* modify it under the terms of the GNU Lesser General Public |
|
* License as published by the Free Software Foundation; either |
|
* version 2.1 of the License, or (at your option) any later version. |
|
* |
|
* Libav is distributed in the hope that it will be useful, |
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
|
* Lesser General Public License for more details. |
|
* |
|
* You should have received a copy of the GNU Lesser General Public |
|
* License along with Libav; if not, write to the Free Software |
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
|
*/ |
|
|
|
#include "libavutil/common.h" |
|
#include "png.h" |
|
#include "pngdsp.h" |
|
|
|
// 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size |
|
#define pb_7f (~0UL/255 * 0x7f) |
|
#define pb_80 (~0UL/255 * 0x80) |
|
|
|
static void add_bytes_l2_c(uint8_t *dst, uint8_t *src1, uint8_t *src2, int w) |
|
{ |
|
long i; |
|
for (i = 0; i <= w - sizeof(long); i += sizeof(long)) { |
|
long a = *(long *)(src1 + i); |
|
long b = *(long *)(src2 + i); |
|
*(long *)(dst + i) = ((a & pb_7f) + (b & pb_7f)) ^ ((a ^ b) & pb_80); |
|
} |
|
for (; i < w; i++) |
|
dst[i] = src1[i] + src2[i]; |
|
} |
|
|
|
void ff_pngdsp_init(PNGDSPContext *dsp) |
|
{ |
|
dsp->add_bytes_l2 = add_bytes_l2_c; |
|
dsp->add_paeth_prediction = ff_add_png_paeth_prediction; |
|
|
|
if (ARCH_X86) ff_pngdsp_init_x86(dsp); |
|
}
|
|
|