Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 891 insertions, 0 deletions

diff --git a/media/ffvpx/libavutil/opt.h b/media/ffvpx/libavutil/opt.h
new file mode 100644
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+++ b/media/ffvpx/libavutil/opt.h
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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 "channel_layout.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 {
+ *     const 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_mallocz(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_iterate() 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_iterate(void **iter)
+ *      {
+ *          const AVClass *c = *iter ? NULL : &child_class;
+ *          *iter = (void*)(uintptr_t)c;
+ *          return c;
+ *      }
+ *      @endcode
+ *      Putting child_next() and child_class_iterate() 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_iterate() are needed. The distinction is that child_next()
+ *      iterates over actually existing objects, while child_class_iterate()
+ *      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_iterate() 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_iterate() 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 makes it possible 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_DICT,
+    AV_OPT_TYPE_UINT64,
+    AV_OPT_TYPE_CONST,
+    AV_OPT_TYPE_IMAGE_SIZE, ///< offset must point to two consecutive integers
+    AV_OPT_TYPE_PIXEL_FMT,
+    AV_OPT_TYPE_SAMPLE_FMT,
+    AV_OPT_TYPE_VIDEO_RATE, ///< offset must point to AVRational
+    AV_OPT_TYPE_DURATION,
+    AV_OPT_TYPE_COLOR,
+#if FF_API_OLD_CHANNEL_LAYOUT
+    AV_OPT_TYPE_CHANNEL_LAYOUT,
+#endif
+    AV_OPT_TYPE_BOOL,
+    AV_OPT_TYPE_CHLAYOUT,
+};
+
+/**
+ * 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
+#define AV_OPT_FLAG_AUDIO_PARAM     8
+#define AV_OPT_FLAG_VIDEO_PARAM     16
+#define AV_OPT_FLAG_SUBTITLE_PARAM  32
+/**
+ * The option is intended 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_BSF_PARAM       (1<<8) ///< a generic parameter which can be set by the user for bit stream filtering
+#define AV_OPT_FLAG_RUNTIME_PARAM   (1<<15) ///< a generic parameter which can be set by the user at runtime
+#define AV_OPT_FLAG_FILTERING_PARAM (1<<16) ///< a generic parameter which can be set by the user for filtering
+#define AV_OPT_FLAG_DEPRECATED      (1<<17) ///< set if option is deprecated, users should refer to AVOption.help text for more information
+#define AV_OPT_FLAG_CHILD_CONSTS    (1<<18) ///< set if option constants can also reside in child objects
+//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;
+
+/**
+ * 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);
+
+/**
+ * Set the values of all AVOption fields to their default values. Only these
+ * AVOption fields for which (opt->flags & mask) == flags will have their
+ * default applied to s.
+ *
+ * @param s an AVOption-enabled struct (its first member must be a pointer to AVClass)
+ * @param mask combination of AV_OPT_FLAG_*
+ * @param flags combination of AV_OPT_FLAG_*
+ */
+void av_opt_set_defaults2(void *s, int mask, int flags);
+
+/**
+ * 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_opt_set() 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 allocated objects 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   (1 << 0) /**< 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   (1 << 1)
+
+/**
+ *  In av_opt_get, return NULL if the option has a pointer type and is set to NULL,
+ *  rather than returning an empty string.
+ */
+#define AV_OPT_ALLOW_NULL (1 << 2)
+
+/**
+ *  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 (1 << 12)
+
+/**
+ * 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_opt_set(). 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(const 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 iter a pointer where iteration state is stored.
+ * @return AVClass corresponding to next potential child or NULL
+ */
+const AVClass *av_opt_child_class_iterate(const AVClass *parent, void **iter);
+
+/**
+ * @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.
+ * If the field is of a dictionary type, it has to be a ':' separated list of
+ * key=value parameters. Values containing ':' special characters must be
+ * escaped.
+ * @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);
+#if FF_API_OLD_CHANNEL_LAYOUT
+attribute_deprecated
+int av_opt_set_channel_layout(void *obj, const char *name, int64_t ch_layout, int search_flags);
+#endif
+int av_opt_set_chlayout(void *obj, const char *name, const AVChannelLayout *layout, int search_flags);
+/**
+ * @note Any old dictionary present is discarded and replaced with a copy of the new one. The
+ * caller still owns val is and responsible for freeing it.
+ */
+int av_opt_set_dict_val(void *obj, const char *name, const AVDictionary *val, 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
+ *
+ * @note if AV_OPT_ALLOW_NULL is set in search_flags in av_opt_get, and the
+ * option is of type AV_OPT_TYPE_STRING, AV_OPT_TYPE_BINARY or AV_OPT_TYPE_DICT
+ * and is set to NULL, *out_val will be set to NULL instead of an allocated
+ * empty string.
+ */
+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);
+#if FF_API_OLD_CHANNEL_LAYOUT
+attribute_deprecated
+int av_opt_get_channel_layout(void *obj, const char *name, int search_flags, int64_t *ch_layout);
+#endif
+int av_opt_get_chlayout(void *obj, const char *name, int search_flags, AVChannelLayout *layout);
+/**
+ * @param[out] out_val The returned dictionary is a copy of the actual value and must
+ * be freed with av_dict_free() by the caller
+ */
+int av_opt_get_dict_val(void *obj, const char *name, int search_flags, AVDictionary **out_val);
+/**
+ * @}
+ */
+/**
+ * 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);
+
+/**
+ * Copy options from src object into dest object.
+ *
+ * The underlying AVClass of both src and dest must coincide. The guarantee
+ * below does not apply if this is not fulfilled.
+ *
+ * Options that require memory allocation (e.g. string or binary) are malloc'ed in dest object.
+ * Original memory allocated for such options is freed unless both src and dest options points to the same memory.
+ *
+ * Even on error it is guaranteed that allocated options from src and dest
+ * no longer alias each other afterwards; in particular calling av_opt_free()
+ * on both src and dest is safe afterwards if dest has been memdup'ed from src.
+ *
+ * @param dest Object to copy from
+ * @param src  Object to copy into
+ * @return 0 on success, negative on error
+ */
+int av_opt_copy(void *dest, const 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);
+
+/**
+ * Check if given option is set to its default value.
+ *
+ * Options o must belong to the obj. This function must not be called to check child's options state.
+ * @see av_opt_is_set_to_default_by_name().
+ *
+ * @param obj  AVClass object to check option on
+ * @param o    option to be checked
+ * @return     >0 when option is set to its default,
+ *              0 when option is not set its default,
+ *             <0 on error
+ */
+int av_opt_is_set_to_default(void *obj, const AVOption *o);
+
+/**
+ * Check if given option is set to its default value.
+ *
+ * @param obj          AVClass object to check option on
+ * @param name         option name
+ * @param search_flags combination of AV_OPT_SEARCH_*
+ * @return             >0 when option is set to its default,
+ *                     0 when option is not set its default,
+ *                     <0 on error
+ */
+int av_opt_is_set_to_default_by_name(void *obj, const char *name, int search_flags);
+
+
+#define AV_OPT_SERIALIZE_SKIP_DEFAULTS              0x00000001  ///< Serialize options that are not set to default values only.
+#define AV_OPT_SERIALIZE_OPT_FLAGS_EXACT            0x00000002  ///< Serialize options that exactly match opt_flags only.
+
+/**
+ * Serialize object's options.
+ *
+ * Create a string containing object's serialized options.
+ * Such string may be passed back to av_opt_set_from_string() in order to restore option values.
+ * A key/value or pairs separator occurring in the serialized value or
+ * name string are escaped through the av_escape() function.
+ *
+ * @param[in]  obj           AVClass object to serialize
+ * @param[in]  opt_flags     serialize options with all the specified flags set (AV_OPT_FLAG)
+ * @param[in]  flags         combination of AV_OPT_SERIALIZE_* flags
+ * @param[out] buffer        Pointer to buffer that will be allocated with string containg serialized options.
+ *                           Buffer must be freed by the caller when is no longer needed.
+ * @param[in]  key_val_sep   character used to separate key from value
+ * @param[in]  pairs_sep     character used to separate two pairs from each other
+ * @return                   >= 0 on success, negative on error
+ * @warning Separators cannot be neither '\\' nor '\0'. They also cannot be the same.
+ */
+int av_opt_serialize(void *obj, int opt_flags, int flags, char **buffer,
+                     const char key_val_sep, const char pairs_sep);
+/**
+ * @}
+ */
+
+#endif /* AVUTIL_OPT_H */