libavutil/opt.h - third_party/ffmpeg - Git at Google

 /*
  * 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_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_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 */
	/*
	* 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_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_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 */