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FFmpeg/libavcodec/vc1_common.h

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/*
* VC-1 and WMV3 decoder
* Copyright (c) 2006-2007 Konstantin Shishkov
* Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_VC1_COMMON_H
#define AVCODEC_VC1_COMMON_H
#include <stdint.h>
#include "libavutil/attributes.h"
/** Markers used in VC-1 AP frame data */
//@{
enum VC1Code {
VC1_CODE_RES0 = 0x00000100,
VC1_CODE_ENDOFSEQ = 0x0000010A,
VC1_CODE_SLICE,
VC1_CODE_FIELD,
VC1_CODE_FRAME,
VC1_CODE_ENTRYPOINT,
VC1_CODE_SEQHDR,
};
//@}
#define IS_MARKER(x) (((x) & ~0xFF) == VC1_CODE_RES0)
/** Available Profiles */
//@{
enum Profile {
PROFILE_SIMPLE,
PROFILE_MAIN,
PROFILE_COMPLEX, ///< TODO: WMV9 specific
PROFILE_ADVANCED
};
//@}
/** Find VC-1 marker in buffer
* @return position where next marker starts or end of buffer if no marker found
*/
static av_always_inline const uint8_t* find_next_marker(const uint8_t *src, const uint8_t *end)
{
uint32_t mrk = 0xFFFFFFFF;
if (end-src < 4)
return end;
while (src < end) {
mrk = (mrk << 8) | *src++;
if (IS_MARKER(mrk))
return src - 4;
}
return end;
}
static av_always_inline int vc1_unescape_buffer(const uint8_t *src, int size, uint8_t *dst)
{
int dsize = 0, i;
if (size < 4) {
for (dsize = 0; dsize < size; dsize++)
*dst++ = *src++;
return size;
}
for (i = 0; i < size; i++, src++) {
if (src[0] == 3 && i >= 2 && !src[-1] && !src[-2] && i < size-1 && src[1] < 4) {
dst[dsize++] = src[1];
src++;
i++;
} else
dst[dsize++] = *src;
}
return dsize;
}
#endif /* AVCODEC_VC1_COMMON_H */