| /* |
| * 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 */ |
