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 AVCODEC_OPT_H
23#define AVCODEC_OPT_H
24
25/**
26 * @file
27 * AVOptions
28 */
29
30#include "libavutil/rational.h"
31#include "avcodec.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 * Looks for an option in obj. Looks 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#if LIBAVCODEC_VERSION_MAJOR < 53
156/**
157 * @see av_set_string2()
158 */
159attribute_deprecated const AVOption *av_set_string(void *obj, const char *name, const char *val);
160
161/**
162 * @return a pointer to the AVOption corresponding to the field set or
163 * NULL if no matching AVOption exists, or if the value val is not
164 * valid
165 * @see av_set_string3()
166 */
167attribute_deprecated const AVOption *av_set_string2(void *obj, const char *name, const char *val, int alloc);
168#endif
169
170/**
171 * Sets the field of obj with the given name to value.
172 *
173 * @param[in] obj A struct whose first element is a pointer to an
174 * AVClass.
175 * @param[in] name the name of the field to set
176 * @param[in] val The value to set. If the field is not of a string
177 * type, then the given string is parsed.
178 * SI postfixes and some named scalars are supported.
179 * If the field is of a numeric type, it has to be a numeric or named
180 * scalar. Behavior with more than one scalar and +- infix operators
181 * is undefined.
182 * If the field is of a flags type, it has to be a sequence of numeric
183 * scalars or named flags separated by '+' or '-'. Prefixing a flag
184 * with '+' causes it to be set without affecting the other flags;
185 * similarly, '-' unsets a flag.
186 * @param[out] o_out if non-NULL put here a pointer to the AVOption
187 * found
188 * @param alloc when 1 then the old value will be av_freed() and the
189 *                     new av_strduped()
190 *              when 0 then no av_free() nor av_strdup() will be used
191 * @return 0 if the value has been set, or an AVERROR code in case of
192 * error:
193 * AVERROR(ENOENT) if no matching option exists
194 * AVERROR(ERANGE) if the value is out of range
195 * AVERROR(EINVAL) if the value is not valid
196 */
197int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out);
198
199const AVOption *av_set_double(void *obj, const char *name, double n);
200const AVOption *av_set_q(void *obj, const char *name, AVRational n);
201const AVOption *av_set_int(void *obj, const char *name, int64_t n);
202double av_get_double(void *obj, const char *name, const AVOption **o_out);
203AVRational av_get_q(void *obj, const char *name, const AVOption **o_out);
204int64_t av_get_int(void *obj, const char *name, const AVOption **o_out);
205const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
206const AVOption *av_next_option(void *obj, const AVOption *last);
207int av_opt_show(void *obj, void *av_log_obj);
208void av_opt_set_defaults(void *s);
209void av_opt_set_defaults2(void *s, int mask, int flags);
210
211#endif /* AVCODEC_OPT_H */
212