summaryrefslogtreecommitdiffstats
path: root/libavcodec/opt.h
blob: 0e39e3db3852d42df0aee5085d19ced4c25b2700 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/*
 * AVOptions
 * copyright (c) 2005 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
 */

#ifndef AVCODEC_OPT_H
#define AVCODEC_OPT_H

/**
 * @file opt.h
 * AVOptions
 */

#include "libavutil/rational.h"
#include "avcodec.h"

enum AVOptionType{
    FF_OPT_TYPE_FLAGS,
    FF_OPT_TYPE_INT,
    FF_OPT_TYPE_INT64,
    FF_OPT_TYPE_DOUBLE,
    FF_OPT_TYPE_FLOAT,
    FF_OPT_TYPE_STRING,
    FF_OPT_TYPE_RATIONAL,
    FF_OPT_TYPE_BINARY,  ///< offset must point to a pointer immediately followed by an int for the length
    FF_OPT_TYPE_CONST=128,
};

/**
 * AVOption
 */
typedef struct AVOption {
    const char *name;

    /**
     * short English help text
     * @todo What about other languages?
     */
    const char *help;

    /**
     * The offset relative to the context structure where the option
     * value is stored. It should be 0 for named constants.
     */
    int offset;
    enum AVOptionType type;

    /**
     * the default value for scalar options
     */
    double default_val;
    double min;                 ///< minimum valid value for the option
    double max;                 ///< maximum valid value for the option

    int flags;
#define AV_OPT_FLAG_ENCODING_PARAM  1   ///< a generic parameter which can be set by the user for muxing or encoding
#define AV_OPT_FLAG_DECODING_PARAM  2   ///< a generic parameter which can be set by the user for demuxing or decoding
#define AV_OPT_FLAG_METADATA        4   ///< some data extracted or inserted into the file like title, comment, ...
#define AV_OPT_FLAG_AUDIO_PARAM     8
#define AV_OPT_FLAG_VIDEO_PARAM     16
#define AV_OPT_FLAG_SUBTITLE_PARAM  32
//FIXME think about enc-audio, ... style flags

    /**
     * The logical unit to which the option belongs. Non-constant
     * options and corresponding named constants share the same
     * unit. May be NULL.
     */
    const char *unit;
} AVOption;


/**
 * Looks for an option in \p obj. Looks only for the options which
 * have the flags set as specified in \p mask and \p flags (that is,
 * for which it is the case that opt->flags & mask == flags).
 *
 * @param[in] obj a pointer to a struct whose first element is a
 * pointer to an AVClass
 * @param[in] name the name of the option to look for
 * @param[in] unit the unit of the option to look for, or any if NULL
 * @return a pointer to the option found, or NULL if no option
 * has been found
 */
const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags);

#if LIBAVCODEC_VERSION_MAJOR < 53
/**
 * @see av_set_string2()
 */
attribute_deprecated const AVOption *av_set_string(void *obj, const char *name, const char *val);

/**
 * @return a pointer to the AVOption corresponding to the field set or
 * NULL if no matching AVOption exists, or if the value \p val is not
 * valid
 * @see av_set_string3()
 */
attribute_deprecated const AVOption *av_set_string2(void *obj, const char *name, const char *val, int alloc);
#endif

/**
 * Sets the field of obj with the given name to value.
 *
 * @param[in] obj A struct whose first element is a pointer to an
 * AVClass.
 * @param[in] name the name of the field to set
 * @param[in] val The value to set. If the field is not of a string
 * type, then the given string is parsed.
 * SI postfixes and some named scalars are supported.
 * If the field is of a numeric type, it has to be a numeric or named
 * scalar. Behavior with more than one scalar and +- infix operators
 * is undefined.
 * If the field is of a flags type, it has to be a sequence of numeric
 * scalars or named flags separated by '+' or '-'. Prefixing a flag
 * with '+' causes it to be set without affecting the other flags;
 * similarly, '-' unsets a flag.
 * @param[out] o_out if non-NULL put here a pointer to the AVOption
 * found
 * @param alloc when 1 then the old value will be av_freed() and the
 *                     new av_strduped()
 *              when 0 then no av_free() nor av_strdup() will be used
 * @return 0 if the value has been set, an AVERROR* error code if no
 * matching option exists, or if the value \p val is not valid
 */
int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out);

const AVOption *av_set_double(void *obj, const char *name, double n);
const AVOption *av_set_q(void *obj, const char *name, AVRational n);
const AVOption *av_set_int(void *obj, const char *name, int64_t n);
double av_get_double(void *obj, const char *name, const AVOption **o_out);
AVRational av_get_q(void *obj, const char *name, const AVOption **o_out);
int64_t av_get_int(void *obj, const char *name, const AVOption **o_out);
const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
const AVOption *av_next_option(void *obj, const AVOption *last);
int av_opt_show(void *obj, void *av_log_obj);
void av_opt_set_defaults(void *s);
void av_opt_set_defaults2(void *s, int mask, int flags);

#endif /* AVCODEC_OPT_H */
OpenPOWER on IntegriCloud