/* * PNG image format * Copyright (c) 2008 Loren Merrit <lorenm@u.washington.edu> * * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "config.h" #include "libavutil/attributes.h" #include "libavutil/intreadwrite.h" #include "libavutil/macros.h" #include "png.h" #include "pngdsp.h" #if HAVE_FAST_64BIT #define BITS 64 typedef uint64_t uint_native; #else #define BITS 32 typedef uint32_t uint_native; #endif #define RN AV_JOIN(AV_RN, BITS) #define RNA AV_JOIN(AV_JOIN(AV_RN, BITS), A) #define WN AV_JOIN(AV_WN, BITS) // 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size #define pb_7f (~(uint_native)0 / 255 * 0x7f) #define pb_80 (~(uint_native)0 / 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 - (int) sizeof(uint_native); i += sizeof(uint_native)) { uint_native a = RNA(src1 + i); uint_native b = RN (src2 + i); WN(dst + i, ((a & pb_7f) + (b & pb_7f)) ^ ((a ^ b) & pb_80)); } for (; i < w; i++) dst[i] = src1[i] + src2[i]; } av_cold 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); #endif }