/*
  * 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"

 
 enum AVOptionType{
     FF_OPT_TYPE_FLAGS,
     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,
 };
 
 /**
  * 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 {
         double dbl;
         const char *str;

         /* TODO those are unused now */
         int64_t i64;
         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_METADATA        4   ///< some data extracted or inserted into the file like title, comment, ...
 #define AV_OPT_FLAG_AUDIO_PARAM     8
 #define AV_OPT_FLAG_VIDEO_PARAM     16
 #define AV_OPT_FLAG_SUBTITLE_PARAM  32
 //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;

 #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

 
 /**
  * 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 when 1 then the old value will be av_freed() and the
  *                     new av_strduped()
  *              when 0 then no av_free() nor av_strdup() will be used
  * @return 0 if the value has been set, or an AVERROR code in case of
  * error:
  * AVERROR(ENOENT) if no matching option exists
  * AVERROR(ERANGE) if the value is out of range
  * AVERROR(EINVAL) if the value is not valid
  */
 int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out);
 
 const AVOption *av_set_double(void *obj, const char *name, double n);
 const AVOption *av_set_q(void *obj, const char *name, AVRational n);
 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);
 const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
 const AVOption *av_next_option(void *obj, const AVOption *last);
 
 /**
  * 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);
 
 void av_opt_set_defaults(void *s);
 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_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);
 

 /**
  * 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);
 

 #define AV_OPT_SEARCH_CHILDREN   0x0001 /**< Search in possible children of the
                                              given object first. */
 
 /**
  * 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.
  * @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);
 

 #endif /* AVUTIL_OPT_H */