Statistics
| Branch: | Revision:

ffmpeg / libavutil / opt.h @ 08675bb3

History | View | Annotate | Download (6.39 KB)

1
/*
2
 * AVOptions
3
 * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
12
 * FFmpeg is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21

    
22
#ifndef AVUTIL_OPT_H
23
#define AVUTIL_OPT_H
24

    
25
/**
26
 * @file
27
 * AVOptions
28
 */
29

    
30
#include "rational.h"
31
#include "avutil.h"
32

    
33
enum AVOptionType{
34
    FF_OPT_TYPE_FLAGS,
35
    FF_OPT_TYPE_INT,
36
    FF_OPT_TYPE_INT64,
37
    FF_OPT_TYPE_DOUBLE,
38
    FF_OPT_TYPE_FLOAT,
39
    FF_OPT_TYPE_STRING,
40
    FF_OPT_TYPE_RATIONAL,
41
    FF_OPT_TYPE_BINARY,  ///< offset must point to a pointer immediately followed by an int for the length
42
    FF_OPT_TYPE_CONST=128,
43
};
44

    
45
/**
46
 * AVOption
47
 */
48
typedef struct AVOption {
49
    const char *name;
50

    
51
    /**
52
     * short English help text
53
     * @todo What about other languages?
54
     */
55
    const char *help;
56

    
57
    /**
58
     * The offset relative to the context structure where the option
59
     * value is stored. It should be 0 for named constants.
60
     */
61
    int offset;
62
    enum AVOptionType type;
63

    
64
    /**
65
     * the default value for scalar options
66
     */
67
    union {
68
        double dbl;
69
        const char *str;
70
    } default_val;
71
    double min;                 ///< minimum valid value for the option
72
    double max;                 ///< maximum valid value for the option
73

    
74
    int flags;
75
#define AV_OPT_FLAG_ENCODING_PARAM  1   ///< a generic parameter which can be set by the user for muxing or encoding
76
#define AV_OPT_FLAG_DECODING_PARAM  2   ///< a generic parameter which can be set by the user for demuxing or decoding
77
#define AV_OPT_FLAG_METADATA        4   ///< some data extracted or inserted into the file like title, comment, ...
78
#define AV_OPT_FLAG_AUDIO_PARAM     8
79
#define AV_OPT_FLAG_VIDEO_PARAM     16
80
#define AV_OPT_FLAG_SUBTITLE_PARAM  32
81
//FIXME think about enc-audio, ... style flags
82

    
83
    /**
84
     * The logical unit to which the option belongs. Non-constant
85
     * options and corresponding named constants share the same
86
     * unit. May be NULL.
87
     */
88
    const char *unit;
89
} AVOption;
90

    
91
/**
92
 * Look for an option in obj. Look only for the options which
93
 * have the flags set as specified in mask and flags (that is,
94
 * for which it is the case that opt->flags & mask == flags).
95
 *
96
 * @param[in] obj a pointer to a struct whose first element is a
97
 * pointer to an AVClass
98
 * @param[in] name the name of the option to look for
99
 * @param[in] unit the unit of the option to look for, or any if NULL
100
 * @return a pointer to the option found, or NULL if no option
101
 * has been found
102
 */
103
const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags);
104

    
105
/**
106
 * Set the field of obj with the given name to value.
107
 *
108
 * @param[in] obj A struct whose first element is a pointer to an
109
 * AVClass.
110
 * @param[in] name the name of the field to set
111
 * @param[in] val The value to set. If the field is not of a string
112
 * type, then the given string is parsed.
113
 * SI postfixes and some named scalars are supported.
114
 * If the field is of a numeric type, it has to be a numeric or named
115
 * scalar. Behavior with more than one scalar and +- infix operators
116
 * is undefined.
117
 * If the field is of a flags type, it has to be a sequence of numeric
118
 * scalars or named flags separated by '+' or '-'. Prefixing a flag
119
 * with '+' causes it to be set without affecting the other flags;
120
 * similarly, '-' unsets a flag.
121
 * @param[out] o_out if non-NULL put here a pointer to the AVOption
122
 * found
123
 * @param alloc when 1 then the old value will be av_freed() and the
124
 *                     new av_strduped()
125
 *              when 0 then no av_free() nor av_strdup() will be used
126
 * @return 0 if the value has been set, or an AVERROR code in case of
127
 * error:
128
 * AVERROR(ENOENT) if no matching option exists
129
 * AVERROR(ERANGE) if the value is out of range
130
 * AVERROR(EINVAL) if the value is not valid
131
 */
132
int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out);
133

    
134
const AVOption *av_set_double(void *obj, const char *name, double n);
135
const AVOption *av_set_q(void *obj, const char *name, AVRational n);
136
const AVOption *av_set_int(void *obj, const char *name, int64_t n);
137
double av_get_double(void *obj, const char *name, const AVOption **o_out);
138
AVRational av_get_q(void *obj, const char *name, const AVOption **o_out);
139
int64_t av_get_int(void *obj, const char *name, const AVOption **o_out);
140
const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
141
const AVOption *av_next_option(void *obj, const AVOption *last);
142

    
143
/**
144
 * Show the obj options.
145
 *
146
 * @param req_flags requested flags for the options to show. Show only the
147
 * options for which it is opt->flags & req_flags.
148
 * @param rej_flags rejected flags for the options to show. Show only the
149
 * options for which it is !(opt->flags & req_flags).
150
 * @param av_log_obj log context to use for showing the options
151
 */
152
int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags);
153

    
154
void av_opt_set_defaults(void *s);
155
void av_opt_set_defaults2(void *s, int mask, int flags);
156

    
157
/**
158
 * Parse the key/value pairs list in opts. For each key/value pair
159
 * found, stores the value in the field in ctx that is named like the
160
 * key. ctx must be an AVClass context, storing is done using
161
 * AVOptions.
162
 *
163
 * @param key_val_sep a 0-terminated list of characters used to
164
 * separate key from value
165
 * @param pairs_sep a 0-terminated list of characters used to separate
166
 * two pairs from each other
167
 * @return the number of successfully set key/value pairs, or a negative
168
 * value corresponding to an AVERROR code in case of error:
169
 * AVERROR(EINVAL) if opts cannot be parsed,
170
 * the error code issued by av_set_string3() if a key/value pair
171
 * cannot be set
172
 */
173
int av_set_options_string(void *ctx, const char *opts,
174
                          const char *key_val_sep, const char *pairs_sep);
175

    
176
#endif /* AVUTIL_OPT_H */