Move AVOptions from libavcodec to libavutil
[libav.git] / libavutil / opt.h
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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
33enum 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 */
48typedef 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 double default_val;
68 double min; ///< minimum valid value for the option
69 double max; ///< maximum valid value for the option
70
71 int flags;
72#define AV_OPT_FLAG_ENCODING_PARAM 1 ///< a generic parameter which can be set by the user for muxing or encoding
73#define AV_OPT_FLAG_DECODING_PARAM 2 ///< a generic parameter which can be set by the user for demuxing or decoding
74#define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ...
75#define AV_OPT_FLAG_AUDIO_PARAM 8
76#define AV_OPT_FLAG_VIDEO_PARAM 16
77#define AV_OPT_FLAG_SUBTITLE_PARAM 32
78//FIXME think about enc-audio, ... style flags
79
80 /**
81 * The logical unit to which the option belongs. Non-constant
82 * options and corresponding named constants share the same
83 * unit. May be NULL.
84 */
85 const char *unit;
86} AVOption;
87
88/**
89 * AVOption2.
90 * THIS IS NOT PART OF THE API/ABI YET!
91 * This is identical to AVOption except that default_val was replaced by
92 * an union, it should be compatible with AVOption on normal platforms.
93 */
94typedef struct AVOption2 {
95 const char *name;
96
97 /**
98 * short English help text
99 * @todo What about other languages?
100 */
101 const char *help;
102
103 /**
104 * The offset relative to the context structure where the option
105 * value is stored. It should be 0 for named constants.
106 */
107 int offset;
108 enum AVOptionType type;
109
110 /**
111 * the default value for scalar options
112 */
113 union {
114 double dbl;
115 const char *str;
116 } default_val;
117
118 double min; ///< minimum valid value for the option
119 double max; ///< maximum valid value for the option
120
121 int flags;
122/*
123#define AV_OPT_FLAG_ENCODING_PARAM 1 ///< a generic parameter which can be set by the user for muxing or encoding
124#define AV_OPT_FLAG_DECODING_PARAM 2 ///< a generic parameter which can be set by the user for demuxing or decoding
125#define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ...
126#define AV_OPT_FLAG_AUDIO_PARAM 8
127#define AV_OPT_FLAG_VIDEO_PARAM 16
128#define AV_OPT_FLAG_SUBTITLE_PARAM 32
129*/
130//FIXME think about enc-audio, ... style flags
131
132 /**
133 * The logical unit to which the option belongs. Non-constant
134 * options and corresponding named constants share the same
135 * unit. May be NULL.
136 */
137 const char *unit;
138} AVOption2;
139
140
141/**
142 * Look for an option in obj. Look only for the options which
143 * have the flags set as specified in mask and flags (that is,
144 * for which it is the case that opt->flags & mask == flags).
145 *
146 * @param[in] obj a pointer to a struct whose first element is a
147 * pointer to an AVClass
148 * @param[in] name the name of the option to look for
149 * @param[in] unit the unit of the option to look for, or any if NULL
150 * @return a pointer to the option found, or NULL if no option
151 * has been found
152 */
153const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags);
154
155/**
156 * Set the field of obj with the given name to value.
157 *
158 * @param[in] obj A struct whose first element is a pointer to an
159 * AVClass.
160 * @param[in] name the name of the field to set
161 * @param[in] val The value to set. If the field is not of a string
162 * type, then the given string is parsed.
163 * SI postfixes and some named scalars are supported.
164 * If the field is of a numeric type, it has to be a numeric or named
165 * scalar. Behavior with more than one scalar and +- infix operators
166 * is undefined.
167 * If the field is of a flags type, it has to be a sequence of numeric
168 * scalars or named flags separated by '+' or '-'. Prefixing a flag
169 * with '+' causes it to be set without affecting the other flags;
170 * similarly, '-' unsets a flag.
171 * @param[out] o_out if non-NULL put here a pointer to the AVOption
172 * found
173 * @param alloc when 1 then the old value will be av_freed() and the
174 * new av_strduped()
175 * when 0 then no av_free() nor av_strdup() will be used
176 * @return 0 if the value has been set, or an AVERROR code in case of
177 * error:
178 * AVERROR(ENOENT) if no matching option exists
179 * AVERROR(ERANGE) if the value is out of range
180 * AVERROR(EINVAL) if the value is not valid
181 */
182int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out);
183
184const AVOption *av_set_double(void *obj, const char *name, double n);
185const AVOption *av_set_q(void *obj, const char *name, AVRational n);
186const AVOption *av_set_int(void *obj, const char *name, int64_t n);
187double av_get_double(void *obj, const char *name, const AVOption **o_out);
188AVRational av_get_q(void *obj, const char *name, const AVOption **o_out);
189int64_t av_get_int(void *obj, const char *name, const AVOption **o_out);
190const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
191const AVOption *av_next_option(void *obj, const AVOption *last);
192
193/**
194 * Show the obj options.
195 *
196 * @param req_flags requested flags for the options to show. Show only the
197 * options for which it is opt->flags & req_flags.
198 * @param rej_flags rejected flags for the options to show. Show only the
199 * options for which it is !(opt->flags & req_flags).
200 * @param av_log_obj log context to use for showing the options
201 */
202int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags);
203
204void av_opt_set_defaults(void *s);
205void av_opt_set_defaults2(void *s, int mask, int flags);
206
207#endif /* AVUTIL_OPT_H */