3 * Copyright (c) 2008 Loren Merrit <lorenm@u.washington.edu>
5 * This file is part of Libav.
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/attributes.h"
23 #include "libavutil/common.h"
27 // 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size
28 #define pb_7f (~0UL / 255 * 0x7f)
29 #define pb_80 (~0UL / 255 * 0x80)
31 static void add_bytes_l2_c(uint8_t *dst
, uint8_t *src1
, uint8_t *src2
, int w
)
34 for (i
= 0; i
<= w
- (int) sizeof(long); i
+= sizeof(long)) {
35 long a
= *(long *)(src1
+ i
);
36 long b
= *(long *)(src2
+ i
);
37 *(long *)(dst
+ i
) = ((a
& pb_7f
) + (b
& pb_7f
)) ^ ((a
^ b
) & pb_80
);
40 dst
[i
] = src1
[i
] + src2
[i
];
43 av_cold
void ff_pngdsp_init(PNGDSPContext
*dsp
)
45 dsp
->add_bytes_l2
= add_bytes_l2_c
;
46 dsp
->add_paeth_prediction
= ff_add_png_paeth_prediction
;
49 ff_pngdsp_init_x86(dsp
);