/* * Copyright (c) 2003-2010 Michael Niedermayer <michaelni@gmx.at> * * 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 */ /** * @file * Accelerated start code search function for start codes common to * MPEG-1/2/4 video, VC-1, H.264/5 * @author Michael Niedermayer <michaelni@gmx.at> */ #include "startcode.h" #include "config.h" int ff_startcode_find_candidate_c(const uint8_t *buf, int size) { int i = 0; #if HAVE_FAST_UNALIGNED /* we check i < size instead of i + 3 / 7 because it is * simpler and there must be FF_INPUT_BUFFER_PADDING_SIZE * bytes at the end. */ #if HAVE_FAST_64BIT while (i < size && !((~*(const uint64_t *)(buf + i) & (*(const uint64_t *)(buf + i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL)) i += 8; #else while (i < size && !((~*(const uint32_t *)(buf + i) & (*(const uint32_t *)(buf + i) - 0x01010101U)) & 0x80808080U)) i += 4; #endif #endif for (; i < size; i++) if (!buf[i]) break; return i; }