| /* |
| * 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; |
| } |
