vc1: Split bits used in libavformat into a separate header
[libav.git] / libavcodec / vc1_common.h
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 Libav.
7 *
8 * Libav 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 * Libav 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 Libav; 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,
35 VC1_CODE_SLICE,
36 VC1_CODE_FIELD,
37 VC1_CODE_FRAME,
38 VC1_CODE_ENTRYPOINT,
39 VC1_CODE_SEQHDR,
40 };
41 //@}
42
43 #define IS_MARKER(x) (((x) & ~0xFF) == VC1_CODE_RES0)
44
45 /** Available Profiles */
46 //@{
47 enum Profile {
48 PROFILE_SIMPLE,
49 PROFILE_MAIN,
50 PROFILE_COMPLEX, ///< TODO: WMV9 specific
51 PROFILE_ADVANCED
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 */
58 static av_always_inline const uint8_t* find_next_marker(const uint8_t *src, const uint8_t *end)
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
72 static av_always_inline int vc1_unescape_buffer(const uint8_t *src, int size, uint8_t *dst)
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 */