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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4349 | Serge | 1 | /* |
| 2 | * PNG image format |
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| 3 | * Copyright (c) 2008 Loren Merrit |
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| 4 | * |
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| 5 | * This file is part of FFmpeg. |
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| 6 | * |
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| 7 | * FFmpeg is free software; you can redistribute it and/or |
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| 8 | * modify it under the terms of the GNU Lesser General Public |
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| 9 | * License as published by the Free Software Foundation; either |
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| 10 | * version 2.1 of the License, or (at your option) any later version. |
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| 11 | * |
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| 12 | * FFmpeg is distributed in the hope that it will be useful, |
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| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 15 | * Lesser General Public License for more details. |
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| 16 | * |
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| 17 | * You should have received a copy of the GNU Lesser General Public |
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| 18 | * License along with FFmpeg; if not, write to the Free Software |
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| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 20 | */ |
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| 21 | |||
| 22 | #include "libavutil/attributes.h" |
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| 23 | #include "libavutil/common.h" |
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| 24 | #include "png.h" |
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| 25 | #include "pngdsp.h" |
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| 26 | |||
| 27 | // 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size |
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| 28 | #define pb_7f (~0UL/255 * 0x7f) |
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| 29 | #define pb_80 (~0UL/255 * 0x80) |
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| 30 | |||
| 31 | static void add_bytes_l2_c(uint8_t *dst, uint8_t *src1, uint8_t *src2, int w) |
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| 32 | { |
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| 33 | long i; |
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| 34 | for (i = 0; i <= w - (int)sizeof(long); i += sizeof(long)) { |
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| 35 | long a = *(long *)(src1 + i); |
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| 36 | long b = *(long *)(src2 + i); |
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| 37 | *(long *)(dst + i) = ((a & pb_7f) + (b & pb_7f)) ^ ((a ^ b) & pb_80); |
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| 38 | } |
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| 39 | for (; i < w; i++) |
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| 40 | dst[i] = src1[i] + src2[i]; |
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| 41 | } |
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| 42 | |||
| 43 | av_cold void ff_pngdsp_init(PNGDSPContext *dsp) |
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| 44 | { |
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| 45 | dsp->add_bytes_l2 = add_bytes_l2_c; |
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| 46 | dsp->add_paeth_prediction = ff_add_png_paeth_prediction; |
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| 47 | |||
| 48 | if (ARCH_X86) ff_pngdsp_init_x86(dsp); |
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| 49 | } |