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vc1_common.h
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1 /*
2  * VC-1 and WMV3 decoder
3  * Copyright (c) 2006-2007 Konstantin Shishkov
4  * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #ifndef AVCODEC_VC1_COMMON_H
24 #define AVCODEC_VC1_COMMON_H
25 
26 #include <stdint.h>
27 
28 #include "libavutil/attributes.h"
29 
30 /** Markers used in VC-1 AP frame data */
31 //@{
32 enum VC1Code {
33  VC1_CODE_RES0 = 0x00000100,
34  VC1_CODE_ENDOFSEQ = 0x0000010A,
40 };
41 //@}
42 
43 #define IS_MARKER(x) (((x) & ~0xFF) == VC1_CODE_RES0)
44 
45 /** Available Profiles */
46 //@{
47 enum Profile {
50  PROFILE_COMPLEX, ///< TODO: WMV9 specific
52 };
53 //@}
54 
55 /** Find VC-1 marker in buffer
56  * @return position where next marker starts or end of buffer if no marker found
57  */
59 {
60  uint32_t mrk = 0xFFFFFFFF;
61 
62  if (end-src < 4)
63  return end;
64  while (src < end) {
65  mrk = (mrk << 8) | *src++;
66  if (IS_MARKER(mrk))
67  return src - 4;
68  }
69  return end;
70 }
71 
73 {
74  int dsize = 0, i;
75 
76  if (size < 4) {
77  for (dsize = 0; dsize < size; dsize++)
78  *dst++ = *src++;
79  return size;
80  }
81  for (i = 0; i < size; i++, src++) {
82  if (src[0] == 3 && i >= 2 && !src[-1] && !src[-2] && i < size-1 && src[1] < 4) {
83  dst[dsize++] = src[1];
84  src++;
85  i++;
86  } else
87  dst[dsize++] = *src;
88  }
89  return dsize;
90 }
91 
92 #endif /* AVCODEC_VC1_COMMON_H */