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- /*
- * 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 AVUTIL_OPT_H
- #define AVUTIL_OPT_H
- /**
- * @file
- * AVOptions
- */
- #include "rational.h"
- #include "avutil.h"
- #include "dict.h"
- #include "log.h"
- #include "pixfmt.h"
- #include "samplefmt.h"
- /**
- * @defgroup avoptions AVOptions
- * @ingroup lavu_data
- * @{
- * AVOptions provide a generic system to declare options on arbitrary structs
- * ("objects"). An option can have a help text, a type and a range of possible
- * values. Options may then be enumerated, read and written to.
- *
- * @section avoptions_implement Implementing AVOptions
- * This section describes how to add AVOptions capabilities to a struct.
- *
- * All AVOptions-related information is stored in an AVClass. Therefore
- * the first member of the struct should be a pointer to an AVClass describing it.
- * The option field of the AVClass must be set to a NULL-terminated static array
- * of AVOptions. Each AVOption must have a non-empty name, a type, a default
- * value and for number-type AVOptions also a range of allowed values. It must
- * also declare an offset in bytes from the start of the struct, where the field
- * associated with this AVOption is located. Other fields in the AVOption struct
- * should also be set when applicable, but are not required.
- *
- * The following example illustrates an AVOptions-enabled struct:
- * @code
- * typedef struct test_struct {
- * AVClass *class;
- * int int_opt;
- * char *str_opt;
- * uint8_t *bin_opt;
- * int bin_len;
- * } test_struct;
- *
- * static const AVOption test_options[] = {
- * { "test_int", "This is a test option of int type.", offsetof(test_struct, int_opt),
- * AV_OPT_TYPE_INT, { .i64 = -1 }, INT_MIN, INT_MAX },
- * { "test_str", "This is a test option of string type.", offsetof(test_struct, str_opt),
- * AV_OPT_TYPE_STRING },
- * { "test_bin", "This is a test option of binary type.", offsetof(test_struct, bin_opt),
- * AV_OPT_TYPE_BINARY },
- * { NULL },
- * };
- *
- * static const AVClass test_class = {
- * .class_name = "test class",
- * .item_name = av_default_item_name,
- * .option = test_options,
- * .version = LIBAVUTIL_VERSION_INT,
- * };
- * @endcode
- *
- * Next, when allocating your struct, you must ensure that the AVClass pointer
- * is set to the correct value. Then, av_opt_set_defaults() can be called to
- * initialize defaults. After that the struct is ready to be used with the
- * AVOptions API.
- *
- * When cleaning up, you may use the av_opt_free() function to automatically
- * free all the allocated string and binary options.
- *
- * Continuing with the above example:
- *
- * @code
- * test_struct *alloc_test_struct(void)
- * {
- * test_struct *ret = av_malloc(sizeof(*ret));
- * ret->class = &test_class;
- * av_opt_set_defaults(ret);
- * return ret;
- * }
- * void free_test_struct(test_struct **foo)
- * {
- * av_opt_free(*foo);
- * av_freep(foo);
- * }
- * @endcode
- *
- * @subsection avoptions_implement_nesting Nesting
- * It may happen that an AVOptions-enabled struct contains another
- * AVOptions-enabled struct as a member (e.g. AVCodecContext in
- * libavcodec exports generic options, while its priv_data field exports
- * codec-specific options). In such a case, it is possible to set up the
- * parent struct to export a child's options. To do that, simply
- * implement AVClass.child_next() and AVClass.child_class_next() in the
- * parent struct's AVClass.
- * Assuming that the test_struct from above now also contains a
- * child_struct field:
- *
- * @code
- * typedef struct child_struct {
- * AVClass *class;
- * int flags_opt;
- * } child_struct;
- * static const AVOption child_opts[] = {
- * { "test_flags", "This is a test option of flags type.",
- * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX },
- * { NULL },
- * };
- * static const AVClass child_class = {
- * .class_name = "child class",
- * .item_name = av_default_item_name,
- * .option = child_opts,
- * .version = LIBAVUTIL_VERSION_INT,
- * };
- *
- * void *child_next(void *obj, void *prev)
- * {
- * test_struct *t = obj;
- * if (!prev && t->child_struct)
- * return t->child_struct;
- * return NULL
- * }
- * const AVClass child_class_next(const AVClass *prev)
- * {
- * return prev ? NULL : &child_class;
- * }
- * @endcode
- * Putting child_next() and child_class_next() as defined above into
- * test_class will now make child_struct's options accessible through
- * test_struct (again, proper setup as described above needs to be done on
- * child_struct right after it is created).
- *
- * From the above example it might not be clear why both child_next()
- * and child_class_next() are needed. The distinction is that child_next()
- * iterates over actually existing objects, while child_class_next()
- * iterates over all possible child classes. E.g. if an AVCodecContext
- * was initialized to use a codec which has private options, then its
- * child_next() will return AVCodecContext.priv_data and finish
- * iterating. OTOH child_class_next() on AVCodecContext.av_class will
- * iterate over all available codecs with private options.
- *
- * @subsection avoptions_implement_named_constants Named constants
- * It is possible to create named constants for options. Simply set the unit
- * field of the option the constants should apply to a string and
- * create the constants themselves as options of type AV_OPT_TYPE_CONST
- * with their unit field set to the same string.
- * Their default_val field should contain the value of the named
- * constant.
- * For example, to add some named constants for the test_flags option
- * above, put the following into the child_opts array:
- * @code
- * { "test_flags", "This is a test option of flags type.",
- * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX, "test_unit" },
- * { "flag1", "This is a flag with value 16", 0, AV_OPT_TYPE_CONST, { .i64 = 16 }, 0, 0, "test_unit" },
- * @endcode
- *
- * @section avoptions_use Using AVOptions
- * This section deals with accessing options in an AVOptions-enabled struct.
- * Such structs in FFmpeg are e.g. AVCodecContext in libavcodec or
- * AVFormatContext in libavformat.
- *
- * @subsection avoptions_use_examine Examining AVOptions
- * The basic functions for examining options are av_opt_next(), which iterates
- * over all options defined for one object, and av_opt_find(), which searches
- * for an option with the given name.
- *
- * The situation is more complicated with nesting. An AVOptions-enabled struct
- * may have AVOptions-enabled children. Passing the AV_OPT_SEARCH_CHILDREN flag
- * to av_opt_find() will make the function search children recursively.
- *
- * For enumerating there are basically two cases. The first is when you want to
- * get all options that may potentially exist on the struct and its children
- * (e.g. when constructing documentation). In that case you should call
- * av_opt_child_class_next() recursively on the parent struct's AVClass. The
- * second case is when you have an already initialized struct with all its
- * children and you want to get all options that can be actually written or read
- * from it. In that case you should call av_opt_child_next() recursively (and
- * av_opt_next() on each result).
- *
- * @subsection avoptions_use_get_set Reading and writing AVOptions
- * When setting options, you often have a string read directly from the
- * user. In such a case, simply passing it to av_opt_set() is enough. For
- * non-string type options, av_opt_set() will parse the string according to the
- * option type.
- *
- * Similarly av_opt_get() will read any option type and convert it to a string
- * which will be returned. Do not forget that the string is allocated, so you
- * have to free it with av_free().
- *
- * In some cases it may be more convenient to put all options into an
- * AVDictionary and call av_opt_set_dict() on it. A specific case of this
- * are the format/codec open functions in lavf/lavc which take a dictionary
- * filled with option as a parameter. This allows to set some options
- * that cannot be set otherwise, since e.g. the input file format is not known
- * before the file is actually opened.
- */
- enum AVOptionType{
- AV_OPT_TYPE_FLAGS,
- AV_OPT_TYPE_INT,
- AV_OPT_TYPE_INT64,
- AV_OPT_TYPE_DOUBLE,
- AV_OPT_TYPE_FLOAT,
- AV_OPT_TYPE_STRING,
- AV_OPT_TYPE_RATIONAL,
- AV_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length
- AV_OPT_TYPE_CONST = 128,
- AV_OPT_TYPE_IMAGE_SIZE = MKBETAG('S','I','Z','E'), ///< offset must point to two consecutive integers
- AV_OPT_TYPE_PIXEL_FMT = MKBETAG('P','F','M','T'),
- AV_OPT_TYPE_SAMPLE_FMT = MKBETAG('S','F','M','T'),
- AV_OPT_TYPE_VIDEO_RATE = MKBETAG('V','R','A','T'), ///< offset must point to AVRational
- AV_OPT_TYPE_DURATION = MKBETAG('D','U','R',' '),
- AV_OPT_TYPE_COLOR = MKBETAG('C','O','L','R'),
- AV_OPT_TYPE_CHANNEL_LAYOUT = MKBETAG('C','H','L','A'),
- #if FF_API_OLD_AVOPTIONS
- FF_OPT_TYPE_FLAGS = 0,
- 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,
- #endif
- };
- /**
- * 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
- */
- union {
- int64_t i64;
- double dbl;
- const char *str;
- /* TODO those are unused now */
- AVRational q;
- } 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
- #if FF_API_OPT_TYPE_METADATA
- #define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ...
- #endif
- #define AV_OPT_FLAG_AUDIO_PARAM 8
- #define AV_OPT_FLAG_VIDEO_PARAM 16
- #define AV_OPT_FLAG_SUBTITLE_PARAM 32
- /**
- * The option is inteded for exporting values to the caller.
- */
- #define AV_OPT_FLAG_EXPORT 64
- /**
- * The option may not be set through the AVOptions API, only read.
- * This flag only makes sense when AV_OPT_FLAG_EXPORT is also set.
- */
- #define AV_OPT_FLAG_READONLY 128
- #define AV_OPT_FLAG_FILTERING_PARAM (1<<16) ///< a generic parameter which can be set by the user for filtering
- //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;
- /**
- * A single allowed range of values, or a single allowed value.
- */
- typedef struct AVOptionRange {
- const char *str;
- /**
- * Value range.
- * For string ranges this represents the min/max length.
- * For dimensions this represents the min/max pixel count or width/height in multi-component case.
- */
- double value_min, value_max;
- /**
- * Value's component range.
- * For string this represents the unicode range for chars, 0-127 limits to ASCII.
- */
- double component_min, component_max;
- /**
- * Range flag.
- * If set to 1 the struct encodes a range, if set to 0 a single value.
- */
- int is_range;
- } AVOptionRange;
- /**
- * List of AVOptionRange structs.
- */
- typedef struct AVOptionRanges {
- /**
- * Array of option ranges.
- *
- * Most of option types use just one component.
- * Following describes multi-component option types:
- *
- * AV_OPT_TYPE_IMAGE_SIZE:
- * component index 0: range of pixel count (width * height).
- * component index 1: range of width.
- * component index 2: range of height.
- *
- * @note To obtain multi-component version of this structure, user must
- * provide AV_OPT_MULTI_COMPONENT_RANGE to av_opt_query_ranges or
- * av_opt_query_ranges_default function.
- *
- * Multi-component range can be read as in following example:
- *
- * @code
- * int range_index, component_index;
- * AVOptionRanges *ranges;
- * AVOptionRange *range[3]; //may require more than 3 in the future.
- * av_opt_query_ranges(&ranges, obj, key, AV_OPT_MULTI_COMPONENT_RANGE);
- * for (range_index = 0; range_index < ranges->nb_ranges; range_index++) {
- * for (component_index = 0; component_index < ranges->nb_components; component_index++)
- * range[component_index] = ranges->range[ranges->nb_ranges * component_index + range_index];
- * //do something with range here.
- * }
- * av_opt_freep_ranges(&ranges);
- * @endcode
- */
- AVOptionRange **range;
- /**
- * Number of ranges per component.
- */
- int nb_ranges;
- /**
- * Number of componentes.
- */
- int nb_components;
- } AVOptionRanges;
- #if FF_API_FIND_OPT
- /**
- * Look for an option in obj. Look only for the options which
- * have the flags set as specified in mask and 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
- *
- * @deprecated use av_opt_find.
- */
- attribute_deprecated
- const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags);
- #endif
- #if FF_API_OLD_AVOPTIONS
- /**
- * Set 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 this parameter is currently ignored
- * @return 0 if the value has been set, or an AVERROR code in case of
- * error:
- * AVERROR_OPTION_NOT_FOUND if no matching option exists
- * AVERROR(ERANGE) if the value is out of range
- * AVERROR(EINVAL) if the value is not valid
- * @deprecated use av_opt_set()
- */
- attribute_deprecated
- int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out);
- attribute_deprecated const AVOption *av_set_double(void *obj, const char *name, double n);
- attribute_deprecated const AVOption *av_set_q(void *obj, const char *name, AVRational n);
- attribute_deprecated 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);
- attribute_deprecated const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
- attribute_deprecated const AVOption *av_next_option(void *obj, const AVOption *last);
- #endif
- /**
- * Show the obj options.
- *
- * @param req_flags requested flags for the options to show. Show only the
- * options for which it is opt->flags & req_flags.
- * @param rej_flags rejected flags for the options to show. Show only the
- * options for which it is !(opt->flags & req_flags).
- * @param av_log_obj log context to use for showing the options
- */
- int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags);
- /**
- * Set the values of all AVOption fields to their default values.
- *
- * @param s an AVOption-enabled struct (its first member must be a pointer to AVClass)
- */
- void av_opt_set_defaults(void *s);
- #if FF_API_OLD_AVOPTIONS
- attribute_deprecated
- void av_opt_set_defaults2(void *s, int mask, int flags);
- #endif
- /**
- * Parse the key/value pairs list in opts. For each key/value pair
- * found, stores the value in the field in ctx that is named like the
- * key. ctx must be an AVClass context, storing is done using
- * AVOptions.
- *
- * @param opts options string to parse, may be NULL
- * @param key_val_sep a 0-terminated list of characters used to
- * separate key from value
- * @param pairs_sep a 0-terminated list of characters used to separate
- * two pairs from each other
- * @return the number of successfully set key/value pairs, or a negative
- * value corresponding to an AVERROR code in case of error:
- * AVERROR(EINVAL) if opts cannot be parsed,
- * the error code issued by av_set_string3() if a key/value pair
- * cannot be set
- */
- int av_set_options_string(void *ctx, const char *opts,
- const char *key_val_sep, const char *pairs_sep);
- /**
- * Parse the key-value pairs list in opts. For each key=value pair found,
- * set the value of the corresponding option in ctx.
- *
- * @param ctx the AVClass object to set options on
- * @param opts the options string, key-value pairs separated by a
- * delimiter
- * @param shorthand a NULL-terminated array of options names for shorthand
- * notation: if the first field in opts has no key part,
- * the key is taken from the first element of shorthand;
- * then again for the second, etc., until either opts is
- * finished, shorthand is finished or a named option is
- * found; after that, all options must be named
- * @param key_val_sep a 0-terminated list of characters used to separate
- * key from value, for example '='
- * @param pairs_sep a 0-terminated list of characters used to separate
- * two pairs from each other, for example ':' or ','
- * @return the number of successfully set key=value pairs, or a negative
- * value corresponding to an AVERROR code in case of error:
- * AVERROR(EINVAL) if opts cannot be parsed,
- * the error code issued by av_set_string3() if a key/value pair
- * cannot be set
- *
- * Options names must use only the following characters: a-z A-Z 0-9 - . / _
- * Separators must use characters distinct from option names and from each
- * other.
- */
- int av_opt_set_from_string(void *ctx, const char *opts,
- const char *const *shorthand,
- const char *key_val_sep, const char *pairs_sep);
- /**
- * Free all string and binary options in obj.
- */
- void av_opt_free(void *obj);
- /**
- * Check whether a particular flag is set in a flags field.
- *
- * @param field_name the name of the flag field option
- * @param flag_name the name of the flag to check
- * @return non-zero if the flag is set, zero if the flag isn't set,
- * isn't of the right type, or the flags field doesn't exist.
- */
- int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name);
- /**
- * Set all the options from a given dictionary on an object.
- *
- * @param obj a struct whose first element is a pointer to AVClass
- * @param options options to process. This dictionary will be freed and replaced
- * by a new one containing all options not found in obj.
- * Of course this new dictionary needs to be freed by caller
- * with av_dict_free().
- *
- * @return 0 on success, a negative AVERROR if some option was found in obj,
- * but could not be set.
- *
- * @see av_dict_copy()
- */
- int av_opt_set_dict(void *obj, struct AVDictionary **options);
- /**
- * Set all the options from a given dictionary on an object.
- *
- * @param obj a struct whose first element is a pointer to AVClass
- * @param options options to process. This dictionary will be freed and replaced
- * by a new one containing all options not found in obj.
- * Of course this new dictionary needs to be freed by caller
- * with av_dict_free().
- * @param search_flags A combination of AV_OPT_SEARCH_*.
- *
- * @return 0 on success, a negative AVERROR if some option was found in obj,
- * but could not be set.
- *
- * @see av_dict_copy()
- */
- int av_opt_set_dict2(void *obj, struct AVDictionary **options, int search_flags);
- /**
- * Extract a key-value pair from the beginning of a string.
- *
- * @param ropts pointer to the options string, will be updated to
- * point to the rest of the string (one of the pairs_sep
- * or the final NUL)
- * @param key_val_sep a 0-terminated list of characters used to separate
- * key from value, for example '='
- * @param pairs_sep a 0-terminated list of characters used to separate
- * two pairs from each other, for example ':' or ','
- * @param flags flags; see the AV_OPT_FLAG_* values below
- * @param rkey parsed key; must be freed using av_free()
- * @param rval parsed value; must be freed using av_free()
- *
- * @return >=0 for success, or a negative value corresponding to an
- * AVERROR code in case of error; in particular:
- * AVERROR(EINVAL) if no key is present
- *
- */
- int av_opt_get_key_value(const char **ropts,
- const char *key_val_sep, const char *pairs_sep,
- unsigned flags,
- char **rkey, char **rval);
- enum {
- /**
- * Accept to parse a value without a key; the key will then be returned
- * as NULL.
- */
- AV_OPT_FLAG_IMPLICIT_KEY = 1,
- };
- /**
- * @defgroup opt_eval_funcs Evaluating option strings
- * @{
- * This group of functions can be used to evaluate option strings
- * and get numbers out of them. They do the same thing as av_opt_set(),
- * except the result is written into the caller-supplied pointer.
- *
- * @param obj a struct whose first element is a pointer to AVClass.
- * @param o an option for which the string is to be evaluated.
- * @param val string to be evaluated.
- * @param *_out value of the string will be written here.
- *
- * @return 0 on success, a negative number on failure.
- */
- int av_opt_eval_flags (void *obj, const AVOption *o, const char *val, int *flags_out);
- int av_opt_eval_int (void *obj, const AVOption *o, const char *val, int *int_out);
- int av_opt_eval_int64 (void *obj, const AVOption *o, const char *val, int64_t *int64_out);
- int av_opt_eval_float (void *obj, const AVOption *o, const char *val, float *float_out);
- int av_opt_eval_double(void *obj, const AVOption *o, const char *val, double *double_out);
- int av_opt_eval_q (void *obj, const AVOption *o, const char *val, AVRational *q_out);
- /**
- * @}
- */
- #define AV_OPT_SEARCH_CHILDREN 0x0001 /**< Search in possible children of the
- given object first. */
- /**
- * The obj passed to av_opt_find() is fake -- only a double pointer to AVClass
- * instead of a required pointer to a struct containing AVClass. This is
- * useful for searching for options without needing to allocate the corresponding
- * object.
- */
- #define AV_OPT_SEARCH_FAKE_OBJ 0x0002
- /**
- * Allows av_opt_query_ranges and av_opt_query_ranges_default to return more than
- * one component for certain option types.
- * @see AVOptionRanges for details.
- */
- #define AV_OPT_MULTI_COMPONENT_RANGE 0x1000
- /**
- * Look for an option in an object. Consider only options which
- * have all the specified flags set.
- *
- * @param[in] obj A pointer to a struct whose first element is a
- * pointer to an AVClass.
- * Alternatively a double pointer to an AVClass, if
- * AV_OPT_SEARCH_FAKE_OBJ search flag is set.
- * @param[in] name The name of the option to look for.
- * @param[in] unit When searching for named constants, name of the unit
- * it belongs to.
- * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG).
- * @param search_flags A combination of AV_OPT_SEARCH_*.
- *
- * @return A pointer to the option found, or NULL if no option
- * was found.
- *
- * @note Options found with AV_OPT_SEARCH_CHILDREN flag may not be settable
- * directly with av_set_string3(). Use special calls which take an options
- * AVDictionary (e.g. avformat_open_input()) to set options found with this
- * flag.
- */
- const AVOption *av_opt_find(void *obj, const char *name, const char *unit,
- int opt_flags, int search_flags);
- /**
- * Look for an option in an object. Consider only options which
- * have all the specified flags set.
- *
- * @param[in] obj A pointer to a struct whose first element is a
- * pointer to an AVClass.
- * Alternatively a double pointer to an AVClass, if
- * AV_OPT_SEARCH_FAKE_OBJ search flag is set.
- * @param[in] name The name of the option to look for.
- * @param[in] unit When searching for named constants, name of the unit
- * it belongs to.
- * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG).
- * @param search_flags A combination of AV_OPT_SEARCH_*.
- * @param[out] target_obj if non-NULL, an object to which the option belongs will be
- * written here. It may be different from obj if AV_OPT_SEARCH_CHILDREN is present
- * in search_flags. This parameter is ignored if search_flags contain
- * AV_OPT_SEARCH_FAKE_OBJ.
- *
- * @return A pointer to the option found, or NULL if no option
- * was found.
- */
- const AVOption *av_opt_find2(void *obj, const char *name, const char *unit,
- int opt_flags, int search_flags, void **target_obj);
- /**
- * Iterate over all AVOptions belonging to obj.
- *
- * @param obj an AVOptions-enabled struct or a double pointer to an
- * AVClass describing it.
- * @param prev result of the previous call to av_opt_next() on this object
- * or NULL
- * @return next AVOption or NULL
- */
- const AVOption *av_opt_next(void *obj, const AVOption *prev);
- /**
- * Iterate over AVOptions-enabled children of obj.
- *
- * @param prev result of a previous call to this function or NULL
- * @return next AVOptions-enabled child or NULL
- */
- void *av_opt_child_next(void *obj, void *prev);
- /**
- * Iterate over potential AVOptions-enabled children of parent.
- *
- * @param prev result of a previous call to this function or NULL
- * @return AVClass corresponding to next potential child or NULL
- */
- const AVClass *av_opt_child_class_next(const AVClass *parent, const AVClass *prev);
- /**
- * @defgroup opt_set_funcs Option setting functions
- * @{
- * Those functions set 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. In case of av_opt_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 search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN
- * is passed here, then the option may be set on a child of obj.
- *
- * @return 0 if the value has been set, or an AVERROR code in case of
- * error:
- * AVERROR_OPTION_NOT_FOUND if no matching option exists
- * AVERROR(ERANGE) if the value is out of range
- * AVERROR(EINVAL) if the value is not valid
- */
- int av_opt_set (void *obj, const char *name, const char *val, int search_flags);
- int av_opt_set_int (void *obj, const char *name, int64_t val, int search_flags);
- int av_opt_set_double(void *obj, const char *name, double val, int search_flags);
- int av_opt_set_q (void *obj, const char *name, AVRational val, int search_flags);
- int av_opt_set_bin (void *obj, const char *name, const uint8_t *val, int size, int search_flags);
- int av_opt_set_image_size(void *obj, const char *name, int w, int h, int search_flags);
- int av_opt_set_pixel_fmt (void *obj, const char *name, enum AVPixelFormat fmt, int search_flags);
- int av_opt_set_sample_fmt(void *obj, const char *name, enum AVSampleFormat fmt, int search_flags);
- int av_opt_set_video_rate(void *obj, const char *name, AVRational val, int search_flags);
- int av_opt_set_channel_layout(void *obj, const char *name, int64_t ch_layout, int search_flags);
- /**
- * Set a binary option to an integer list.
- *
- * @param obj AVClass object to set options on
- * @param name name of the binary option
- * @param val pointer to an integer list (must have the correct type with
- * regard to the contents of the list)
- * @param term list terminator (usually 0 or -1)
- * @param flags search flags
- */
- #define av_opt_set_int_list(obj, name, val, term, flags) \
- (av_int_list_length(val, term) > INT_MAX / sizeof(*(val)) ? \
- AVERROR(EINVAL) : \
- av_opt_set_bin(obj, name, (const uint8_t *)(val), \
- av_int_list_length(val, term) * sizeof(*(val)), flags))
- /**
- * @}
- */
- /**
- * @defgroup opt_get_funcs Option getting functions
- * @{
- * Those functions get a value of the option with the given name from an object.
- *
- * @param[in] obj a struct whose first element is a pointer to an AVClass.
- * @param[in] name name of the option to get.
- * @param[in] search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN
- * is passed here, then the option may be found in a child of obj.
- * @param[out] out_val value of the option will be written here
- * @return >=0 on success, a negative error code otherwise
- */
- /**
- * @note the returned string will be av_malloc()ed and must be av_free()ed by the caller
- */
- int av_opt_get (void *obj, const char *name, int search_flags, uint8_t **out_val);
- int av_opt_get_int (void *obj, const char *name, int search_flags, int64_t *out_val);
- int av_opt_get_double(void *obj, const char *name, int search_flags, double *out_val);
- int av_opt_get_q (void *obj, const char *name, int search_flags, AVRational *out_val);
- int av_opt_get_image_size(void *obj, const char *name, int search_flags, int *w_out, int *h_out);
- int av_opt_get_pixel_fmt (void *obj, const char *name, int search_flags, enum AVPixelFormat *out_fmt);
- int av_opt_get_sample_fmt(void *obj, const char *name, int search_flags, enum AVSampleFormat *out_fmt);
- int av_opt_get_video_rate(void *obj, const char *name, int search_flags, AVRational *out_val);
- int av_opt_get_channel_layout(void *obj, const char *name, int search_flags, int64_t *ch_layout);
- /**
- * @}
- */
- /**
- * Gets a pointer to the requested field in a struct.
- * This function allows accessing a struct even when its fields are moved or
- * renamed since the application making the access has been compiled,
- *
- * @returns a pointer to the field, it can be cast to the correct type and read
- * or written to.
- */
- void *av_opt_ptr(const AVClass *avclass, void *obj, const char *name);
- /**
- * Free an AVOptionRanges struct and set it to NULL.
- */
- void av_opt_freep_ranges(AVOptionRanges **ranges);
- /**
- * Get a list of allowed ranges for the given option.
- *
- * The returned list may depend on other fields in obj like for example profile.
- *
- * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored
- * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance
- * AV_OPT_MULTI_COMPONENT_RANGE indicates that function may return more than one component, @see AVOptionRanges
- *
- * The result must be freed with av_opt_freep_ranges.
- *
- * @return number of compontents returned on success, a negative errro code otherwise
- */
- int av_opt_query_ranges(AVOptionRanges **, void *obj, const char *key, int flags);
- int av_opt_copy(void *dest, void *src);
- /**
- * Get a default list of allowed ranges for the given option.
- *
- * This list is constructed without using the AVClass.query_ranges() callback
- * and can be used as fallback from within the callback.
- *
- * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored
- * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance
- * AV_OPT_MULTI_COMPONENT_RANGE indicates that function may return more than one component, @see AVOptionRanges
- *
- * The result must be freed with av_opt_free_ranges.
- *
- * @return number of compontents returned on success, a negative errro code otherwise
- */
- int av_opt_query_ranges_default(AVOptionRanges **, void *obj, const char *key, int flags);
- /**
- * @}
- */
- #endif /* AVUTIL_OPT_H */
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