libx264: fix setting some more parameters
[libav.git] / libavutil / opt.h
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1/*
2 * AVOptions
3 * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
4 *
2912e87a 5 * This file is part of Libav.
6ed04040 6 *
2912e87a 7 * Libav is free software; you can redistribute it and/or
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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 *
2912e87a 12 * Libav is distributed in the hope that it will be useful,
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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
2912e87a 18 * License along with Libav; if not, write to the Free Software
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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"
7e83e1c5 32#include "dict.h"
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33
34enum AVOptionType{
35 FF_OPT_TYPE_FLAGS,
36 FF_OPT_TYPE_INT,
37 FF_OPT_TYPE_INT64,
38 FF_OPT_TYPE_DOUBLE,
39 FF_OPT_TYPE_FLOAT,
40 FF_OPT_TYPE_STRING,
41 FF_OPT_TYPE_RATIONAL,
42 FF_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length
43 FF_OPT_TYPE_CONST=128,
44};
45
46/**
47 * AVOption
48 */
49typedef struct AVOption {
50 const char *name;
51
52 /**
53 * short English help text
54 * @todo What about other languages?
55 */
56 const char *help;
57
58 /**
59 * The offset relative to the context structure where the option
60 * value is stored. It should be 0 for named constants.
61 */
62 int offset;
63 enum AVOptionType type;
64
65 /**
66 * the default value for scalar options
67 */
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68 union {
69 double dbl;
70 const char *str;
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71 /* TODO those are unused now */
72 int64_t i64;
73 AVRational q;
6ed04040 74 } default_val;
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75 double min; ///< minimum valid value for the option
76 double max; ///< maximum valid value for the option
77
78 int flags;
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79#define AV_OPT_FLAG_ENCODING_PARAM 1 ///< a generic parameter which can be set by the user for muxing or encoding
80#define AV_OPT_FLAG_DECODING_PARAM 2 ///< a generic parameter which can be set by the user for demuxing or decoding
81#define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ...
82#define AV_OPT_FLAG_AUDIO_PARAM 8
83#define AV_OPT_FLAG_VIDEO_PARAM 16
84#define AV_OPT_FLAG_SUBTITLE_PARAM 32
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85//FIXME think about enc-audio, ... style flags
86
87 /**
88 * The logical unit to which the option belongs. Non-constant
89 * options and corresponding named constants share the same
90 * unit. May be NULL.
91 */
92 const char *unit;
b6675279 93} AVOption;
6ed04040 94
dc59ec5e 95#if FF_API_FIND_OPT
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96/**
97 * Look for an option in obj. Look only for the options which
98 * have the flags set as specified in mask and flags (that is,
99 * for which it is the case that opt->flags & mask == flags).
100 *
101 * @param[in] obj a pointer to a struct whose first element is a
102 * pointer to an AVClass
103 * @param[in] name the name of the option to look for
104 * @param[in] unit the unit of the option to look for, or any if NULL
105 * @return a pointer to the option found, or NULL if no option
106 * has been found
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107 *
108 * @deprecated use av_opt_find.
6ed04040 109 */
dc59ec5e 110attribute_deprecated
6ed04040 111const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags);
dc59ec5e 112#endif
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113
114/**
115 * Set the field of obj with the given name to value.
116 *
117 * @param[in] obj A struct whose first element is a pointer to an
118 * AVClass.
119 * @param[in] name the name of the field to set
120 * @param[in] val The value to set. If the field is not of a string
121 * type, then the given string is parsed.
122 * SI postfixes and some named scalars are supported.
123 * If the field is of a numeric type, it has to be a numeric or named
124 * scalar. Behavior with more than one scalar and +- infix operators
125 * is undefined.
126 * If the field is of a flags type, it has to be a sequence of numeric
127 * scalars or named flags separated by '+' or '-'. Prefixing a flag
128 * with '+' causes it to be set without affecting the other flags;
129 * similarly, '-' unsets a flag.
130 * @param[out] o_out if non-NULL put here a pointer to the AVOption
131 * found
132 * @param alloc when 1 then the old value will be av_freed() and the
133 * new av_strduped()
134 * when 0 then no av_free() nor av_strdup() will be used
135 * @return 0 if the value has been set, or an AVERROR code in case of
136 * error:
e955a682 137 * AVERROR_OPTION_NOT_FOUND if no matching option exists
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138 * AVERROR(ERANGE) if the value is out of range
139 * AVERROR(EINVAL) if the value is not valid
140 */
141int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out);
142
143const AVOption *av_set_double(void *obj, const char *name, double n);
144const AVOption *av_set_q(void *obj, const char *name, AVRational n);
145const AVOption *av_set_int(void *obj, const char *name, int64_t n);
146double av_get_double(void *obj, const char *name, const AVOption **o_out);
147AVRational av_get_q(void *obj, const char *name, const AVOption **o_out);
148int64_t av_get_int(void *obj, const char *name, const AVOption **o_out);
149const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
150const AVOption *av_next_option(void *obj, const AVOption *last);
151
152/**
153 * Show the obj options.
154 *
155 * @param req_flags requested flags for the options to show. Show only the
156 * options for which it is opt->flags & req_flags.
157 * @param rej_flags rejected flags for the options to show. Show only the
158 * options for which it is !(opt->flags & req_flags).
159 * @param av_log_obj log context to use for showing the options
160 */
161int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags);
162
163void av_opt_set_defaults(void *s);
164void av_opt_set_defaults2(void *s, int mask, int flags);
165
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166/**
167 * Parse the key/value pairs list in opts. For each key/value pair
168 * found, stores the value in the field in ctx that is named like the
169 * key. ctx must be an AVClass context, storing is done using
170 * AVOptions.
171 *
172 * @param key_val_sep a 0-terminated list of characters used to
173 * separate key from value
174 * @param pairs_sep a 0-terminated list of characters used to separate
175 * two pairs from each other
176 * @return the number of successfully set key/value pairs, or a negative
177 * value corresponding to an AVERROR code in case of error:
178 * AVERROR(EINVAL) if opts cannot be parsed,
179 * the error code issued by av_set_string3() if a key/value pair
180 * cannot be set
181 */
182int av_set_options_string(void *ctx, const char *opts,
183 const char *key_val_sep, const char *pairs_sep);
184
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185/**
186 * Free all string and binary options in obj.
187 */
188void av_opt_free(void *obj);
189
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190/**
191 * Check whether a particular flag is set in a flags field.
192 *
193 * @param field_name the name of the flag field option
194 * @param flag_name the name of the flag to check
195 * @return non-zero if the flag is set, zero if the flag isn't set,
196 * isn't of the right type, or the flags field doesn't exist.
197 */
198int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name);
199
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200/*
201 * Set all the options from a given dictionary on an object.
202 *
203 * @param obj a struct whose first element is a pointer to AVClass
204 * @param options options to process. This dictionary will be freed and replaced
205 * by a new one containing all options not found in obj.
206 * Of course this new dictionary needs to be freed by caller
207 * with av_dict_free().
208 *
209 * @return 0 on success, a negative AVERROR if some option was found in obj,
210 * but could not be set.
211 *
212 * @see av_dict_copy()
213 */
214int av_opt_set_dict(void *obj, struct AVDictionary **options);
215
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216#define AV_OPT_SEARCH_CHILDREN 0x0001 /**< Search in possible children of the
217 given object first. */
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218/**
219 * The obj passed to av_opt_find() is fake -- only a double pointer to AVClass
220 * instead of a required pointer to a struct containing AVClass. This is
221 * useful for searching for options without needing to allocate the corresponding
222 * object.
223 */
224#define AV_OPT_SEARCH_FAKE_OBJ 0x0002
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225
226/**
227 * Look for an option in an object. Consider only options which
228 * have all the specified flags set.
229 *
230 * @param[in] obj A pointer to a struct whose first element is a
231 * pointer to an AVClass.
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232 * Alternatively a double pointer to an AVClass, if
233 * AV_OPT_SEARCH_FAKE_OBJ search flag is set.
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234 * @param[in] name The name of the option to look for.
235 * @param[in] unit When searching for named constants, name of the unit
236 * it belongs to.
237 * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG).
238 * @param search_flags A combination of AV_OPT_SEARCH_*.
239 *
240 * @return A pointer to the option found, or NULL if no option
241 * was found.
242 *
243 * @note Options found with AV_OPT_SEARCH_CHILDREN flag may not be settable
244 * directly with av_set_string3(). Use special calls which take an options
245 * AVDictionary (e.g. avformat_open_input()) to set options found with this
246 * flag.
247 */
248const AVOption *av_opt_find(void *obj, const char *name, const char *unit,
249 int opt_flags, int search_flags);
250
6ed04040 251#endif /* AVUTIL_OPT_H */