aac5773f
 hucm
功能基本完成，接口待打磨
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/*
* 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 AV_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;
}
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