FFmpeg
unary.h
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1 /*
2  * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_UNARY_H
22 #define AVCODEC_UNARY_H
23 
24 #include "get_bits.h"
25 
26 /**
27  * Get unary code of limited length
28  * @param gb GetBitContext
29  * @param[in] stop The bitstop value (unary code of 1's or 0's)
30  * @param[in] len Maximum length
31  * @return unary 0 based code index. This is also the length in bits of the
32  * code excluding the stop bit.
33  * (in case len=1)
34  * 1 0
35  * 0 1
36  * (in case len=2)
37  * 1 0
38  * 01 1
39  * 00 2
40  * (in case len=3)
41  * 1 0
42  * 01 1
43  * 001 2
44  * 000 3
45  */
46 static inline int get_unary(GetBitContext *gb, int stop, int len)
47 {
48  int i;
49 
50  for(i = 0; i < len && get_bits1(gb) != stop; i++);
51  return i;
52 }
53 
54 /**
55  * Get unary code terminated by a 0 with a maximum length of 33
56  * @param gb GetBitContext
57  * @return Unary length/index
58  */
59 static inline int get_unary_0_33(GetBitContext *gb)
60 {
61  return get_unary(gb, 0, 33);
62 }
63 
64 static inline int get_unary_0_9(GetBitContext *gb)
65 {
66  return get_unary(gb, 0, 9);
67 }
68 
69 #endif /* AVCODEC_UNARY_H */
static int get_unary_0_33(GetBitContext *gb)
Get unary code terminated by a 0 with a maximum length of 33.
Definition: unary.h:59
static int get_unary_0_9(GetBitContext *gb)
Definition: unary.h:64
bitstream reader API header.
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
static int get_unary(GetBitContext *gb, int stop, int len)
Get unary code of limited length.
Definition: unary.h:46
int len