| 1 | /* |
| 2 | * AVOptions |
| 3 | * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at> |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | #ifndef AVUTIL_OPT_H |
| 23 | #define AVUTIL_OPT_H |
| 24 | |
| 25 | /** |
| 26 | * @file |
| 27 | * AVOptions |
| 28 | */ |
| 29 | |
| 30 | #include "rational.h" |
| 31 | #include "avutil.h" |
| 32 | #include "dict.h" |
| 33 | #include "log.h" |
| 34 | #include "pixfmt.h" |
| 35 | #include "samplefmt.h" |
| 36 | #include "version.h" |
| 37 | |
| 38 | /** |
| 39 | * @defgroup avoptions AVOptions |
| 40 | * @ingroup lavu_data |
| 41 | * @{ |
| 42 | * AVOptions provide a generic system to declare options on arbitrary structs |
| 43 | * ("objects"). An option can have a help text, a type and a range of possible |
| 44 | * values. Options may then be enumerated, read and written to. |
| 45 | * |
| 46 | * @section avoptions_implement Implementing AVOptions |
| 47 | * This section describes how to add AVOptions capabilities to a struct. |
| 48 | * |
| 49 | * All AVOptions-related information is stored in an AVClass. Therefore |
| 50 | * the first member of the struct should be a pointer to an AVClass describing it. |
| 51 | * The option field of the AVClass must be set to a NULL-terminated static array |
| 52 | * of AVOptions. Each AVOption must have a non-empty name, a type, a default |
| 53 | * value and for number-type AVOptions also a range of allowed values. It must |
| 54 | * also declare an offset in bytes from the start of the struct, where the field |
| 55 | * associated with this AVOption is located. Other fields in the AVOption struct |
| 56 | * should also be set when applicable, but are not required. |
| 57 | * |
| 58 | * The following example illustrates an AVOptions-enabled struct: |
| 59 | * @code |
| 60 | * typedef struct test_struct { |
| 61 | * AVClass *class; |
| 62 | * int int_opt; |
| 63 | * char *str_opt; |
| 64 | * uint8_t *bin_opt; |
| 65 | * int bin_len; |
| 66 | * } test_struct; |
| 67 | * |
| 68 | * static const AVOption test_options[] = { |
| 69 | * { "test_int", "This is a test option of int type.", offsetof(test_struct, int_opt), |
| 70 | * AV_OPT_TYPE_INT, { .i64 = -1 }, INT_MIN, INT_MAX }, |
| 71 | * { "test_str", "This is a test option of string type.", offsetof(test_struct, str_opt), |
| 72 | * AV_OPT_TYPE_STRING }, |
| 73 | * { "test_bin", "This is a test option of binary type.", offsetof(test_struct, bin_opt), |
| 74 | * AV_OPT_TYPE_BINARY }, |
| 75 | * { NULL }, |
| 76 | * }; |
| 77 | * |
| 78 | * static const AVClass test_class = { |
| 79 | * .class_name = "test class", |
| 80 | * .item_name = av_default_item_name, |
| 81 | * .option = test_options, |
| 82 | * .version = LIBAVUTIL_VERSION_INT, |
| 83 | * }; |
| 84 | * @endcode |
| 85 | * |
| 86 | * Next, when allocating your struct, you must ensure that the AVClass pointer |
| 87 | * is set to the correct value. Then, av_opt_set_defaults() can be called to |
| 88 | * initialize defaults. After that the struct is ready to be used with the |
| 89 | * AVOptions API. |
| 90 | * |
| 91 | * When cleaning up, you may use the av_opt_free() function to automatically |
| 92 | * free all the allocated string and binary options. |
| 93 | * |
| 94 | * Continuing with the above example: |
| 95 | * |
| 96 | * @code |
| 97 | * test_struct *alloc_test_struct(void) |
| 98 | * { |
| 99 | * test_struct *ret = av_malloc(sizeof(*ret)); |
| 100 | * ret->class = &test_class; |
| 101 | * av_opt_set_defaults(ret); |
| 102 | * return ret; |
| 103 | * } |
| 104 | * void free_test_struct(test_struct **foo) |
| 105 | * { |
| 106 | * av_opt_free(*foo); |
| 107 | * av_freep(foo); |
| 108 | * } |
| 109 | * @endcode |
| 110 | * |
| 111 | * @subsection avoptions_implement_nesting Nesting |
| 112 | * It may happen that an AVOptions-enabled struct contains another |
| 113 | * AVOptions-enabled struct as a member (e.g. AVCodecContext in |
| 114 | * libavcodec exports generic options, while its priv_data field exports |
| 115 | * codec-specific options). In such a case, it is possible to set up the |
| 116 | * parent struct to export a child's options. To do that, simply |
| 117 | * implement AVClass.child_next() and AVClass.child_class_next() in the |
| 118 | * parent struct's AVClass. |
| 119 | * Assuming that the test_struct from above now also contains a |
| 120 | * child_struct field: |
| 121 | * |
| 122 | * @code |
| 123 | * typedef struct child_struct { |
| 124 | * AVClass *class; |
| 125 | * int flags_opt; |
| 126 | * } child_struct; |
| 127 | * static const AVOption child_opts[] = { |
| 128 | * { "test_flags", "This is a test option of flags type.", |
| 129 | * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX }, |
| 130 | * { NULL }, |
| 131 | * }; |
| 132 | * static const AVClass child_class = { |
| 133 | * .class_name = "child class", |
| 134 | * .item_name = av_default_item_name, |
| 135 | * .option = child_opts, |
| 136 | * .version = LIBAVUTIL_VERSION_INT, |
| 137 | * }; |
| 138 | * |
| 139 | * void *child_next(void *obj, void *prev) |
| 140 | * { |
| 141 | * test_struct *t = obj; |
| 142 | * if (!prev && t->child_struct) |
| 143 | * return t->child_struct; |
| 144 | * return NULL |
| 145 | * } |
| 146 | * const AVClass child_class_next(const AVClass *prev) |
| 147 | * { |
| 148 | * return prev ? NULL : &child_class; |
| 149 | * } |
| 150 | * @endcode |
| 151 | * Putting child_next() and child_class_next() as defined above into |
| 152 | * test_class will now make child_struct's options accessible through |
| 153 | * test_struct (again, proper setup as described above needs to be done on |
| 154 | * child_struct right after it is created). |
| 155 | * |
| 156 | * From the above example it might not be clear why both child_next() |
| 157 | * and child_class_next() are needed. The distinction is that child_next() |
| 158 | * iterates over actually existing objects, while child_class_next() |
| 159 | * iterates over all possible child classes. E.g. if an AVCodecContext |
| 160 | * was initialized to use a codec which has private options, then its |
| 161 | * child_next() will return AVCodecContext.priv_data and finish |
| 162 | * iterating. OTOH child_class_next() on AVCodecContext.av_class will |
| 163 | * iterate over all available codecs with private options. |
| 164 | * |
| 165 | * @subsection avoptions_implement_named_constants Named constants |
| 166 | * It is possible to create named constants for options. Simply set the unit |
| 167 | * field of the option the constants should apply to a string and |
| 168 | * create the constants themselves as options of type AV_OPT_TYPE_CONST |
| 169 | * with their unit field set to the same string. |
| 170 | * Their default_val field should contain the value of the named |
| 171 | * constant. |
| 172 | * For example, to add some named constants for the test_flags option |
| 173 | * above, put the following into the child_opts array: |
| 174 | * @code |
| 175 | * { "test_flags", "This is a test option of flags type.", |
| 176 | * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX, "test_unit" }, |
| 177 | * { "flag1", "This is a flag with value 16", 0, AV_OPT_TYPE_CONST, { .i64 = 16 }, 0, 0, "test_unit" }, |
| 178 | * @endcode |
| 179 | * |
| 180 | * @section avoptions_use Using AVOptions |
| 181 | * This section deals with accessing options in an AVOptions-enabled struct. |
| 182 | * Such structs in FFmpeg are e.g. AVCodecContext in libavcodec or |
| 183 | * AVFormatContext in libavformat. |
| 184 | * |
| 185 | * @subsection avoptions_use_examine Examining AVOptions |
| 186 | * The basic functions for examining options are av_opt_next(), which iterates |
| 187 | * over all options defined for one object, and av_opt_find(), which searches |
| 188 | * for an option with the given name. |
| 189 | * |
| 190 | * The situation is more complicated with nesting. An AVOptions-enabled struct |
| 191 | * may have AVOptions-enabled children. Passing the AV_OPT_SEARCH_CHILDREN flag |
| 192 | * to av_opt_find() will make the function search children recursively. |
| 193 | * |
| 194 | * For enumerating there are basically two cases. The first is when you want to |
| 195 | * get all options that may potentially exist on the struct and its children |
| 196 | * (e.g. when constructing documentation). In that case you should call |
| 197 | * av_opt_child_class_next() recursively on the parent struct's AVClass. The |
| 198 | * second case is when you have an already initialized struct with all its |
| 199 | * children and you want to get all options that can be actually written or read |
| 200 | * from it. In that case you should call av_opt_child_next() recursively (and |
| 201 | * av_opt_next() on each result). |
| 202 | * |
| 203 | * @subsection avoptions_use_get_set Reading and writing AVOptions |
| 204 | * When setting options, you often have a string read directly from the |
| 205 | * user. In such a case, simply passing it to av_opt_set() is enough. For |
| 206 | * non-string type options, av_opt_set() will parse the string according to the |
| 207 | * option type. |
| 208 | * |
| 209 | * Similarly av_opt_get() will read any option type and convert it to a string |
| 210 | * which will be returned. Do not forget that the string is allocated, so you |
| 211 | * have to free it with av_free(). |
| 212 | * |
| 213 | * In some cases it may be more convenient to put all options into an |
| 214 | * AVDictionary and call av_opt_set_dict() on it. A specific case of this |
| 215 | * are the format/codec open functions in lavf/lavc which take a dictionary |
| 216 | * filled with option as a parameter. This allows to set some options |
| 217 | * that cannot be set otherwise, since e.g. the input file format is not known |
| 218 | * before the file is actually opened. |
| 219 | */ |
| 220 | |
| 221 | enum AVOptionType{ |
| 222 | AV_OPT_TYPE_FLAGS, |
| 223 | AV_OPT_TYPE_INT, |
| 224 | AV_OPT_TYPE_INT64, |
| 225 | AV_OPT_TYPE_DOUBLE, |
| 226 | AV_OPT_TYPE_FLOAT, |
| 227 | AV_OPT_TYPE_STRING, |
| 228 | AV_OPT_TYPE_RATIONAL, |
| 229 | AV_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length |
| 230 | AV_OPT_TYPE_DICT, |
| 231 | AV_OPT_TYPE_CONST = 128, |
| 232 | AV_OPT_TYPE_IMAGE_SIZE = MKBETAG('S','I','Z','E'), ///< offset must point to two consecutive integers |
| 233 | AV_OPT_TYPE_PIXEL_FMT = MKBETAG('P','F','M','T'), |
| 234 | AV_OPT_TYPE_SAMPLE_FMT = MKBETAG('S','F','M','T'), |
| 235 | AV_OPT_TYPE_VIDEO_RATE = MKBETAG('V','R','A','T'), ///< offset must point to AVRational |
| 236 | AV_OPT_TYPE_DURATION = MKBETAG('D','U','R',' '), |
| 237 | AV_OPT_TYPE_COLOR = MKBETAG('C','O','L','R'), |
| 238 | AV_OPT_TYPE_CHANNEL_LAYOUT = MKBETAG('C','H','L','A'), |
| 239 | #if FF_API_OLD_AVOPTIONS |
| 240 | FF_OPT_TYPE_FLAGS = 0, |
| 241 | FF_OPT_TYPE_INT, |
| 242 | FF_OPT_TYPE_INT64, |
| 243 | FF_OPT_TYPE_DOUBLE, |
| 244 | FF_OPT_TYPE_FLOAT, |
| 245 | FF_OPT_TYPE_STRING, |
| 246 | FF_OPT_TYPE_RATIONAL, |
| 247 | FF_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length |
| 248 | FF_OPT_TYPE_CONST=128, |
| 249 | #endif |
| 250 | }; |
| 251 | |
| 252 | /** |
| 253 | * AVOption |
| 254 | */ |
| 255 | typedef struct AVOption { |
| 256 | const char *name; |
| 257 | |
| 258 | /** |
| 259 | * short English help text |
| 260 | * @todo What about other languages? |
| 261 | */ |
| 262 | const char *help; |
| 263 | |
| 264 | /** |
| 265 | * The offset relative to the context structure where the option |
| 266 | * value is stored. It should be 0 for named constants. |
| 267 | */ |
| 268 | int offset; |
| 269 | enum AVOptionType type; |
| 270 | |
| 271 | /** |
| 272 | * the default value for scalar options |
| 273 | */ |
| 274 | union { |
| 275 | int64_t i64; |
| 276 | double dbl; |
| 277 | const char *str; |
| 278 | /* TODO those are unused now */ |
| 279 | AVRational q; |
| 280 | } default_val; |
| 281 | double min; ///< minimum valid value for the option |
| 282 | double max; ///< maximum valid value for the option |
| 283 | |
| 284 | int flags; |
| 285 | #define AV_OPT_FLAG_ENCODING_PARAM 1 ///< a generic parameter which can be set by the user for muxing or encoding |
| 286 | #define AV_OPT_FLAG_DECODING_PARAM 2 ///< a generic parameter which can be set by the user for demuxing or decoding |
| 287 | #if FF_API_OPT_TYPE_METADATA |
| 288 | #define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ... |
| 289 | #endif |
| 290 | #define AV_OPT_FLAG_AUDIO_PARAM 8 |
| 291 | #define AV_OPT_FLAG_VIDEO_PARAM 16 |
| 292 | #define AV_OPT_FLAG_SUBTITLE_PARAM 32 |
| 293 | /** |
| 294 | * The option is inteded for exporting values to the caller. |
| 295 | */ |
| 296 | #define AV_OPT_FLAG_EXPORT 64 |
| 297 | /** |
| 298 | * The option may not be set through the AVOptions API, only read. |
| 299 | * This flag only makes sense when AV_OPT_FLAG_EXPORT is also set. |
| 300 | */ |
| 301 | #define AV_OPT_FLAG_READONLY 128 |
| 302 | #define AV_OPT_FLAG_FILTERING_PARAM (1<<16) ///< a generic parameter which can be set by the user for filtering |
| 303 | //FIXME think about enc-audio, ... style flags |
| 304 | |
| 305 | /** |
| 306 | * The logical unit to which the option belongs. Non-constant |
| 307 | * options and corresponding named constants share the same |
| 308 | * unit. May be NULL. |
| 309 | */ |
| 310 | const char *unit; |
| 311 | } AVOption; |
| 312 | |
| 313 | /** |
| 314 | * A single allowed range of values, or a single allowed value. |
| 315 | */ |
| 316 | typedef struct AVOptionRange { |
| 317 | const char *str; |
| 318 | /** |
| 319 | * Value range. |
| 320 | * For string ranges this represents the min/max length. |
| 321 | * For dimensions this represents the min/max pixel count or width/height in multi-component case. |
| 322 | */ |
| 323 | double value_min, value_max; |
| 324 | /** |
| 325 | * Value's component range. |
| 326 | * For string this represents the unicode range for chars, 0-127 limits to ASCII. |
| 327 | */ |
| 328 | double component_min, component_max; |
| 329 | /** |
| 330 | * Range flag. |
| 331 | * If set to 1 the struct encodes a range, if set to 0 a single value. |
| 332 | */ |
| 333 | int is_range; |
| 334 | } AVOptionRange; |
| 335 | |
| 336 | /** |
| 337 | * List of AVOptionRange structs. |
| 338 | */ |
| 339 | typedef struct AVOptionRanges { |
| 340 | /** |
| 341 | * Array of option ranges. |
| 342 | * |
| 343 | * Most of option types use just one component. |
| 344 | * Following describes multi-component option types: |
| 345 | * |
| 346 | * AV_OPT_TYPE_IMAGE_SIZE: |
| 347 | * component index 0: range of pixel count (width * height). |
| 348 | * component index 1: range of width. |
| 349 | * component index 2: range of height. |
| 350 | * |
| 351 | * @note To obtain multi-component version of this structure, user must |
| 352 | * provide AV_OPT_MULTI_COMPONENT_RANGE to av_opt_query_ranges or |
| 353 | * av_opt_query_ranges_default function. |
| 354 | * |
| 355 | * Multi-component range can be read as in following example: |
| 356 | * |
| 357 | * @code |
| 358 | * int range_index, component_index; |
| 359 | * AVOptionRanges *ranges; |
| 360 | * AVOptionRange *range[3]; //may require more than 3 in the future. |
| 361 | * av_opt_query_ranges(&ranges, obj, key, AV_OPT_MULTI_COMPONENT_RANGE); |
| 362 | * for (range_index = 0; range_index < ranges->nb_ranges; range_index++) { |
| 363 | * for (component_index = 0; component_index < ranges->nb_components; component_index++) |
| 364 | * range[component_index] = ranges->range[ranges->nb_ranges * component_index + range_index]; |
| 365 | * //do something with range here. |
| 366 | * } |
| 367 | * av_opt_freep_ranges(&ranges); |
| 368 | * @endcode |
| 369 | */ |
| 370 | AVOptionRange **range; |
| 371 | /** |
| 372 | * Number of ranges per component. |
| 373 | */ |
| 374 | int nb_ranges; |
| 375 | /** |
| 376 | * Number of componentes. |
| 377 | */ |
| 378 | int nb_components; |
| 379 | } AVOptionRanges; |
| 380 | |
| 381 | |
| 382 | #if FF_API_OLD_AVOPTIONS |
| 383 | /** |
| 384 | * Set the field of obj with the given name to value. |
| 385 | * |
| 386 | * @param[in] obj A struct whose first element is a pointer to an |
| 387 | * AVClass. |
| 388 | * @param[in] name the name of the field to set |
| 389 | * @param[in] val The value to set. If the field is not of a string |
| 390 | * type, then the given string is parsed. |
| 391 | * SI postfixes and some named scalars are supported. |
| 392 | * If the field is of a numeric type, it has to be a numeric or named |
| 393 | * scalar. Behavior with more than one scalar and +- infix operators |
| 394 | * is undefined. |
| 395 | * If the field is of a flags type, it has to be a sequence of numeric |
| 396 | * scalars or named flags separated by '+' or '-'. Prefixing a flag |
| 397 | * with '+' causes it to be set without affecting the other flags; |
| 398 | * similarly, '-' unsets a flag. |
| 399 | * @param[out] o_out if non-NULL put here a pointer to the AVOption |
| 400 | * found |
| 401 | * @param alloc this parameter is currently ignored |
| 402 | * @return 0 if the value has been set, or an AVERROR code in case of |
| 403 | * error: |
| 404 | * AVERROR_OPTION_NOT_FOUND if no matching option exists |
| 405 | * AVERROR(ERANGE) if the value is out of range |
| 406 | * AVERROR(EINVAL) if the value is not valid |
| 407 | * @deprecated use av_opt_set() |
| 408 | */ |
| 409 | attribute_deprecated |
| 410 | int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out); |
| 411 | |
| 412 | attribute_deprecated const AVOption *av_set_double(void *obj, const char *name, double n); |
| 413 | attribute_deprecated const AVOption *av_set_q(void *obj, const char *name, AVRational n); |
| 414 | attribute_deprecated const AVOption *av_set_int(void *obj, const char *name, int64_t n); |
| 415 | |
| 416 | double av_get_double(void *obj, const char *name, const AVOption **o_out); |
| 417 | AVRational av_get_q(void *obj, const char *name, const AVOption **o_out); |
| 418 | int64_t av_get_int(void *obj, const char *name, const AVOption **o_out); |
| 419 | attribute_deprecated const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len); |
| 420 | attribute_deprecated const AVOption *av_next_option(FF_CONST_AVUTIL55 void *obj, const AVOption *last); |
| 421 | #endif |
| 422 | |
| 423 | /** |
| 424 | * Show the obj options. |
| 425 | * |
| 426 | * @param req_flags requested flags for the options to show. Show only the |
| 427 | * options for which it is opt->flags & req_flags. |
| 428 | * @param rej_flags rejected flags for the options to show. Show only the |
| 429 | * options for which it is !(opt->flags & req_flags). |
| 430 | * @param av_log_obj log context to use for showing the options |
| 431 | */ |
| 432 | int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags); |
| 433 | |
| 434 | /** |
| 435 | * Set the values of all AVOption fields to their default values. |
| 436 | * |
| 437 | * @param s an AVOption-enabled struct (its first member must be a pointer to AVClass) |
| 438 | */ |
| 439 | void av_opt_set_defaults(void *s); |
| 440 | |
| 441 | #if FF_API_OLD_AVOPTIONS |
| 442 | attribute_deprecated |
| 443 | void av_opt_set_defaults2(void *s, int mask, int flags); |
| 444 | #endif |
| 445 | |
| 446 | /** |
| 447 | * Parse the key/value pairs list in opts. For each key/value pair |
| 448 | * found, stores the value in the field in ctx that is named like the |
| 449 | * key. ctx must be an AVClass context, storing is done using |
| 450 | * AVOptions. |
| 451 | * |
| 452 | * @param opts options string to parse, may be NULL |
| 453 | * @param key_val_sep a 0-terminated list of characters used to |
| 454 | * separate key from value |
| 455 | * @param pairs_sep a 0-terminated list of characters used to separate |
| 456 | * two pairs from each other |
| 457 | * @return the number of successfully set key/value pairs, or a negative |
| 458 | * value corresponding to an AVERROR code in case of error: |
| 459 | * AVERROR(EINVAL) if opts cannot be parsed, |
| 460 | * the error code issued by av_opt_set() if a key/value pair |
| 461 | * cannot be set |
| 462 | */ |
| 463 | int av_set_options_string(void *ctx, const char *opts, |
| 464 | const char *key_val_sep, const char *pairs_sep); |
| 465 | |
| 466 | /** |
| 467 | * Parse the key-value pairs list in opts. For each key=value pair found, |
| 468 | * set the value of the corresponding option in ctx. |
| 469 | * |
| 470 | * @param ctx the AVClass object to set options on |
| 471 | * @param opts the options string, key-value pairs separated by a |
| 472 | * delimiter |
| 473 | * @param shorthand a NULL-terminated array of options names for shorthand |
| 474 | * notation: if the first field in opts has no key part, |
| 475 | * the key is taken from the first element of shorthand; |
| 476 | * then again for the second, etc., until either opts is |
| 477 | * finished, shorthand is finished or a named option is |
| 478 | * found; after that, all options must be named |
| 479 | * @param key_val_sep a 0-terminated list of characters used to separate |
| 480 | * key from value, for example '=' |
| 481 | * @param pairs_sep a 0-terminated list of characters used to separate |
| 482 | * two pairs from each other, for example ':' or ',' |
| 483 | * @return the number of successfully set key=value pairs, or a negative |
| 484 | * value corresponding to an AVERROR code in case of error: |
| 485 | * AVERROR(EINVAL) if opts cannot be parsed, |
| 486 | * the error code issued by av_set_string3() if a key/value pair |
| 487 | * cannot be set |
| 488 | * |
| 489 | * Options names must use only the following characters: a-z A-Z 0-9 - . / _ |
| 490 | * Separators must use characters distinct from option names and from each |
| 491 | * other. |
| 492 | */ |
| 493 | int av_opt_set_from_string(void *ctx, const char *opts, |
| 494 | const char *const *shorthand, |
| 495 | const char *key_val_sep, const char *pairs_sep); |
| 496 | /** |
| 497 | * Free all allocated objects in obj. |
| 498 | */ |
| 499 | void av_opt_free(void *obj); |
| 500 | |
| 501 | /** |
| 502 | * Check whether a particular flag is set in a flags field. |
| 503 | * |
| 504 | * @param field_name the name of the flag field option |
| 505 | * @param flag_name the name of the flag to check |
| 506 | * @return non-zero if the flag is set, zero if the flag isn't set, |
| 507 | * isn't of the right type, or the flags field doesn't exist. |
| 508 | */ |
| 509 | int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name); |
| 510 | |
| 511 | /** |
| 512 | * Set all the options from a given dictionary on an object. |
| 513 | * |
| 514 | * @param obj a struct whose first element is a pointer to AVClass |
| 515 | * @param options options to process. This dictionary will be freed and replaced |
| 516 | * by a new one containing all options not found in obj. |
| 517 | * Of course this new dictionary needs to be freed by caller |
| 518 | * with av_dict_free(). |
| 519 | * |
| 520 | * @return 0 on success, a negative AVERROR if some option was found in obj, |
| 521 | * but could not be set. |
| 522 | * |
| 523 | * @see av_dict_copy() |
| 524 | */ |
| 525 | int av_opt_set_dict(void *obj, struct AVDictionary **options); |
| 526 | |
| 527 | |
| 528 | /** |
| 529 | * Set all the options from a given dictionary on an object. |
| 530 | * |
| 531 | * @param obj a struct whose first element is a pointer to AVClass |
| 532 | * @param options options to process. This dictionary will be freed and replaced |
| 533 | * by a new one containing all options not found in obj. |
| 534 | * Of course this new dictionary needs to be freed by caller |
| 535 | * with av_dict_free(). |
| 536 | * @param search_flags A combination of AV_OPT_SEARCH_*. |
| 537 | * |
| 538 | * @return 0 on success, a negative AVERROR if some option was found in obj, |
| 539 | * but could not be set. |
| 540 | * |
| 541 | * @see av_dict_copy() |
| 542 | */ |
| 543 | int av_opt_set_dict2(void *obj, struct AVDictionary **options, int search_flags); |
| 544 | |
| 545 | /** |
| 546 | * Extract a key-value pair from the beginning of a string. |
| 547 | * |
| 548 | * @param ropts pointer to the options string, will be updated to |
| 549 | * point to the rest of the string (one of the pairs_sep |
| 550 | * or the final NUL) |
| 551 | * @param key_val_sep a 0-terminated list of characters used to separate |
| 552 | * key from value, for example '=' |
| 553 | * @param pairs_sep a 0-terminated list of characters used to separate |
| 554 | * two pairs from each other, for example ':' or ',' |
| 555 | * @param flags flags; see the AV_OPT_FLAG_* values below |
| 556 | * @param rkey parsed key; must be freed using av_free() |
| 557 | * @param rval parsed value; must be freed using av_free() |
| 558 | * |
| 559 | * @return >=0 for success, or a negative value corresponding to an |
| 560 | * AVERROR code in case of error; in particular: |
| 561 | * AVERROR(EINVAL) if no key is present |
| 562 | * |
| 563 | */ |
| 564 | int av_opt_get_key_value(const char **ropts, |
| 565 | const char *key_val_sep, const char *pairs_sep, |
| 566 | unsigned flags, |
| 567 | char **rkey, char **rval); |
| 568 | |
| 569 | enum { |
| 570 | |
| 571 | /** |
| 572 | * Accept to parse a value without a key; the key will then be returned |
| 573 | * as NULL. |
| 574 | */ |
| 575 | AV_OPT_FLAG_IMPLICIT_KEY = 1, |
| 576 | }; |
| 577 | |
| 578 | /** |
| 579 | * @defgroup opt_eval_funcs Evaluating option strings |
| 580 | * @{ |
| 581 | * This group of functions can be used to evaluate option strings |
| 582 | * and get numbers out of them. They do the same thing as av_opt_set(), |
| 583 | * except the result is written into the caller-supplied pointer. |
| 584 | * |
| 585 | * @param obj a struct whose first element is a pointer to AVClass. |
| 586 | * @param o an option for which the string is to be evaluated. |
| 587 | * @param val string to be evaluated. |
| 588 | * @param *_out value of the string will be written here. |
| 589 | * |
| 590 | * @return 0 on success, a negative number on failure. |
| 591 | */ |
| 592 | int av_opt_eval_flags (void *obj, const AVOption *o, const char *val, int *flags_out); |
| 593 | int av_opt_eval_int (void *obj, const AVOption *o, const char *val, int *int_out); |
| 594 | int av_opt_eval_int64 (void *obj, const AVOption *o, const char *val, int64_t *int64_out); |
| 595 | int av_opt_eval_float (void *obj, const AVOption *o, const char *val, float *float_out); |
| 596 | int av_opt_eval_double(void *obj, const AVOption *o, const char *val, double *double_out); |
| 597 | int av_opt_eval_q (void *obj, const AVOption *o, const char *val, AVRational *q_out); |
| 598 | /** |
| 599 | * @} |
| 600 | */ |
| 601 | |
| 602 | #define AV_OPT_SEARCH_CHILDREN 0x0001 /**< Search in possible children of the |
| 603 | given object first. */ |
| 604 | /** |
| 605 | * The obj passed to av_opt_find() is fake -- only a double pointer to AVClass |
| 606 | * instead of a required pointer to a struct containing AVClass. This is |
| 607 | * useful for searching for options without needing to allocate the corresponding |
| 608 | * object. |
| 609 | */ |
| 610 | #define AV_OPT_SEARCH_FAKE_OBJ 0x0002 |
| 611 | |
| 612 | /** |
| 613 | * Allows av_opt_query_ranges and av_opt_query_ranges_default to return more than |
| 614 | * one component for certain option types. |
| 615 | * @see AVOptionRanges for details. |
| 616 | */ |
| 617 | #define AV_OPT_MULTI_COMPONENT_RANGE 0x1000 |
| 618 | |
| 619 | /** |
| 620 | * Look for an option in an object. Consider only options which |
| 621 | * have all the specified flags set. |
| 622 | * |
| 623 | * @param[in] obj A pointer to a struct whose first element is a |
| 624 | * pointer to an AVClass. |
| 625 | * Alternatively a double pointer to an AVClass, if |
| 626 | * AV_OPT_SEARCH_FAKE_OBJ search flag is set. |
| 627 | * @param[in] name The name of the option to look for. |
| 628 | * @param[in] unit When searching for named constants, name of the unit |
| 629 | * it belongs to. |
| 630 | * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG). |
| 631 | * @param search_flags A combination of AV_OPT_SEARCH_*. |
| 632 | * |
| 633 | * @return A pointer to the option found, or NULL if no option |
| 634 | * was found. |
| 635 | * |
| 636 | * @note Options found with AV_OPT_SEARCH_CHILDREN flag may not be settable |
| 637 | * directly with av_opt_set(). Use special calls which take an options |
| 638 | * AVDictionary (e.g. avformat_open_input()) to set options found with this |
| 639 | * flag. |
| 640 | */ |
| 641 | const AVOption *av_opt_find(void *obj, const char *name, const char *unit, |
| 642 | int opt_flags, int search_flags); |
| 643 | |
| 644 | /** |
| 645 | * Look for an option in an object. Consider only options which |
| 646 | * have all the specified flags set. |
| 647 | * |
| 648 | * @param[in] obj A pointer to a struct whose first element is a |
| 649 | * pointer to an AVClass. |
| 650 | * Alternatively a double pointer to an AVClass, if |
| 651 | * AV_OPT_SEARCH_FAKE_OBJ search flag is set. |
| 652 | * @param[in] name The name of the option to look for. |
| 653 | * @param[in] unit When searching for named constants, name of the unit |
| 654 | * it belongs to. |
| 655 | * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG). |
| 656 | * @param search_flags A combination of AV_OPT_SEARCH_*. |
| 657 | * @param[out] target_obj if non-NULL, an object to which the option belongs will be |
| 658 | * written here. It may be different from obj if AV_OPT_SEARCH_CHILDREN is present |
| 659 | * in search_flags. This parameter is ignored if search_flags contain |
| 660 | * AV_OPT_SEARCH_FAKE_OBJ. |
| 661 | * |
| 662 | * @return A pointer to the option found, or NULL if no option |
| 663 | * was found. |
| 664 | */ |
| 665 | const AVOption *av_opt_find2(void *obj, const char *name, const char *unit, |
| 666 | int opt_flags, int search_flags, void **target_obj); |
| 667 | |
| 668 | /** |
| 669 | * Iterate over all AVOptions belonging to obj. |
| 670 | * |
| 671 | * @param obj an AVOptions-enabled struct or a double pointer to an |
| 672 | * AVClass describing it. |
| 673 | * @param prev result of the previous call to av_opt_next() on this object |
| 674 | * or NULL |
| 675 | * @return next AVOption or NULL |
| 676 | */ |
| 677 | const AVOption *av_opt_next(FF_CONST_AVUTIL55 void *obj, const AVOption *prev); |
| 678 | |
| 679 | /** |
| 680 | * Iterate over AVOptions-enabled children of obj. |
| 681 | * |
| 682 | * @param prev result of a previous call to this function or NULL |
| 683 | * @return next AVOptions-enabled child or NULL |
| 684 | */ |
| 685 | void *av_opt_child_next(void *obj, void *prev); |
| 686 | |
| 687 | /** |
| 688 | * Iterate over potential AVOptions-enabled children of parent. |
| 689 | * |
| 690 | * @param prev result of a previous call to this function or NULL |
| 691 | * @return AVClass corresponding to next potential child or NULL |
| 692 | */ |
| 693 | const AVClass *av_opt_child_class_next(const AVClass *parent, const AVClass *prev); |
| 694 | |
| 695 | /** |
| 696 | * @defgroup opt_set_funcs Option setting functions |
| 697 | * @{ |
| 698 | * Those functions set the field of obj with the given name to value. |
| 699 | * |
| 700 | * @param[in] obj A struct whose first element is a pointer to an AVClass. |
| 701 | * @param[in] name the name of the field to set |
| 702 | * @param[in] val The value to set. In case of av_opt_set() if the field is not |
| 703 | * of a string type, then the given string is parsed. |
| 704 | * SI postfixes and some named scalars are supported. |
| 705 | * If the field is of a numeric type, it has to be a numeric or named |
| 706 | * scalar. Behavior with more than one scalar and +- infix operators |
| 707 | * is undefined. |
| 708 | * If the field is of a flags type, it has to be a sequence of numeric |
| 709 | * scalars or named flags separated by '+' or '-'. Prefixing a flag |
| 710 | * with '+' causes it to be set without affecting the other flags; |
| 711 | * similarly, '-' unsets a flag. |
| 712 | * @param search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN |
| 713 | * is passed here, then the option may be set on a child of obj. |
| 714 | * |
| 715 | * @return 0 if the value has been set, or an AVERROR code in case of |
| 716 | * error: |
| 717 | * AVERROR_OPTION_NOT_FOUND if no matching option exists |
| 718 | * AVERROR(ERANGE) if the value is out of range |
| 719 | * AVERROR(EINVAL) if the value is not valid |
| 720 | */ |
| 721 | int av_opt_set (void *obj, const char *name, const char *val, int search_flags); |
| 722 | int av_opt_set_int (void *obj, const char *name, int64_t val, int search_flags); |
| 723 | int av_opt_set_double (void *obj, const char *name, double val, int search_flags); |
| 724 | int av_opt_set_q (void *obj, const char *name, AVRational val, int search_flags); |
| 725 | int av_opt_set_bin (void *obj, const char *name, const uint8_t *val, int size, int search_flags); |
| 726 | int av_opt_set_image_size(void *obj, const char *name, int w, int h, int search_flags); |
| 727 | int av_opt_set_pixel_fmt (void *obj, const char *name, enum AVPixelFormat fmt, int search_flags); |
| 728 | int av_opt_set_sample_fmt(void *obj, const char *name, enum AVSampleFormat fmt, int search_flags); |
| 729 | int av_opt_set_video_rate(void *obj, const char *name, AVRational val, int search_flags); |
| 730 | int av_opt_set_channel_layout(void *obj, const char *name, int64_t ch_layout, int search_flags); |
| 731 | /** |
| 732 | * @note Any old dictionary present is discarded and replaced with a copy of the new one. The |
| 733 | * caller still owns val is and responsible for freeing it. |
| 734 | */ |
| 735 | int av_opt_set_dict_val(void *obj, const char *name, const AVDictionary *val, int search_flags); |
| 736 | |
| 737 | /** |
| 738 | * Set a binary option to an integer list. |
| 739 | * |
| 740 | * @param obj AVClass object to set options on |
| 741 | * @param name name of the binary option |
| 742 | * @param val pointer to an integer list (must have the correct type with |
| 743 | * regard to the contents of the list) |
| 744 | * @param term list terminator (usually 0 or -1) |
| 745 | * @param flags search flags |
| 746 | */ |
| 747 | #define av_opt_set_int_list(obj, name, val, term, flags) \ |
| 748 | (av_int_list_length(val, term) > INT_MAX / sizeof(*(val)) ? \ |
| 749 | AVERROR(EINVAL) : \ |
| 750 | av_opt_set_bin(obj, name, (const uint8_t *)(val), \ |
| 751 | av_int_list_length(val, term) * sizeof(*(val)), flags)) |
| 752 | |
| 753 | /** |
| 754 | * @} |
| 755 | */ |
| 756 | |
| 757 | /** |
| 758 | * @defgroup opt_get_funcs Option getting functions |
| 759 | * @{ |
| 760 | * Those functions get a value of the option with the given name from an object. |
| 761 | * |
| 762 | * @param[in] obj a struct whose first element is a pointer to an AVClass. |
| 763 | * @param[in] name name of the option to get. |
| 764 | * @param[in] search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN |
| 765 | * is passed here, then the option may be found in a child of obj. |
| 766 | * @param[out] out_val value of the option will be written here |
| 767 | * @return >=0 on success, a negative error code otherwise |
| 768 | */ |
| 769 | /** |
| 770 | * @note the returned string will be av_malloc()ed and must be av_free()ed by the caller |
| 771 | */ |
| 772 | int av_opt_get (void *obj, const char *name, int search_flags, uint8_t **out_val); |
| 773 | int av_opt_get_int (void *obj, const char *name, int search_flags, int64_t *out_val); |
| 774 | int av_opt_get_double (void *obj, const char *name, int search_flags, double *out_val); |
| 775 | int av_opt_get_q (void *obj, const char *name, int search_flags, AVRational *out_val); |
| 776 | int av_opt_get_image_size(void *obj, const char *name, int search_flags, int *w_out, int *h_out); |
| 777 | int av_opt_get_pixel_fmt (void *obj, const char *name, int search_flags, enum AVPixelFormat *out_fmt); |
| 778 | int av_opt_get_sample_fmt(void *obj, const char *name, int search_flags, enum AVSampleFormat *out_fmt); |
| 779 | int av_opt_get_video_rate(void *obj, const char *name, int search_flags, AVRational *out_val); |
| 780 | int av_opt_get_channel_layout(void *obj, const char *name, int search_flags, int64_t *ch_layout); |
| 781 | /** |
| 782 | * @param[out] out_val The returned dictionary is a copy of the actual value and must |
| 783 | * be freed with av_dict_free() by the caller |
| 784 | */ |
| 785 | int av_opt_get_dict_val(void *obj, const char *name, int search_flags, AVDictionary **out_val); |
| 786 | /** |
| 787 | * @} |
| 788 | */ |
| 789 | /** |
| 790 | * Gets a pointer to the requested field in a struct. |
| 791 | * This function allows accessing a struct even when its fields are moved or |
| 792 | * renamed since the application making the access has been compiled, |
| 793 | * |
| 794 | * @returns a pointer to the field, it can be cast to the correct type and read |
| 795 | * or written to. |
| 796 | */ |
| 797 | void *av_opt_ptr(const AVClass *avclass, void *obj, const char *name); |
| 798 | |
| 799 | /** |
| 800 | * Free an AVOptionRanges struct and set it to NULL. |
| 801 | */ |
| 802 | void av_opt_freep_ranges(AVOptionRanges **ranges); |
| 803 | |
| 804 | /** |
| 805 | * Get a list of allowed ranges for the given option. |
| 806 | * |
| 807 | * The returned list may depend on other fields in obj like for example profile. |
| 808 | * |
| 809 | * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored |
| 810 | * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance |
| 811 | * AV_OPT_MULTI_COMPONENT_RANGE indicates that function may return more than one component, @see AVOptionRanges |
| 812 | * |
| 813 | * The result must be freed with av_opt_freep_ranges. |
| 814 | * |
| 815 | * @return number of compontents returned on success, a negative errro code otherwise |
| 816 | */ |
| 817 | int av_opt_query_ranges(AVOptionRanges **, void *obj, const char *key, int flags); |
| 818 | |
| 819 | /** |
| 820 | * Copy options from src object into dest object. |
| 821 | * |
| 822 | * Options that require memory allocation (e.g. string or binary) are malloc'ed in dest object. |
| 823 | * Original memory allocated for such options is freed unless both src and dest options points to the same memory. |
| 824 | * |
| 825 | * @param dest Object to copy from |
| 826 | * @param src Object to copy into |
| 827 | * @return 0 on success, negative on error |
| 828 | */ |
| 829 | int av_opt_copy(void *dest, FF_CONST_AVUTIL55 void *src); |
| 830 | |
| 831 | /** |
| 832 | * Get a default list of allowed ranges for the given option. |
| 833 | * |
| 834 | * This list is constructed without using the AVClass.query_ranges() callback |
| 835 | * and can be used as fallback from within the callback. |
| 836 | * |
| 837 | * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored |
| 838 | * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance |
| 839 | * AV_OPT_MULTI_COMPONENT_RANGE indicates that function may return more than one component, @see AVOptionRanges |
| 840 | * |
| 841 | * The result must be freed with av_opt_free_ranges. |
| 842 | * |
| 843 | * @return number of compontents returned on success, a negative errro code otherwise |
| 844 | */ |
| 845 | int av_opt_query_ranges_default(AVOptionRanges **, void *obj, const char *key, int flags); |
| 846 | |
| 847 | /** |
| 848 | * Check if given option is set to its default value. |
| 849 | * |
| 850 | * Options o must belong to the obj. This function must not be called to check child's options state. |
| 851 | * @see av_opt_is_set_to_default_by_name(). |
| 852 | * |
| 853 | * @param obj AVClass object to check option on |
| 854 | * @param o option to be checked |
| 855 | * @return >0 when option is set to its default, |
| 856 | * 0 when option is not set its default, |
| 857 | * <0 on error |
| 858 | */ |
| 859 | int av_opt_is_set_to_default(void *obj, const AVOption *o); |
| 860 | |
| 861 | /** |
| 862 | * Check if given option is set to its default value. |
| 863 | * |
| 864 | * @param obj AVClass object to check option on |
| 865 | * @param name option name |
| 866 | * @param search_flags combination of AV_OPT_SEARCH_* |
| 867 | * @return >0 when option is set to its default, |
| 868 | * 0 when option is not set its default, |
| 869 | * <0 on error |
| 870 | */ |
| 871 | int av_opt_is_set_to_default_by_name(void *obj, const char *name, int search_flags); |
| 872 | |
| 873 | |
| 874 | #define AV_OPT_SERIALIZE_SKIP_DEFAULTS 0x00000001 ///< Serialize options that are not set to default values only. |
| 875 | #define AV_OPT_SERIALIZE_OPT_FLAGS_EXACT 0x00000002 ///< Serialize options that exactly match opt_flags only. |
| 876 | |
| 877 | /** |
| 878 | * Serialize object's options. |
| 879 | * |
| 880 | * Create a string containing object's serialized options. |
| 881 | * Such string may be passed back to av_opt_set_from_string() in order to restore option values. |
| 882 | * A key/value or pairs separator occurring in the serialized value or |
| 883 | * name string are escaped through the av_escape() function. |
| 884 | * |
| 885 | * @param[in] obj AVClass object to serialize |
| 886 | * @param[in] opt_flags serialize options with all the specified flags set (AV_OPT_FLAG) |
| 887 | * @param[in] flags combination of AV_OPT_SERIALIZE_* flags |
| 888 | * @param[out] buffer Pointer to buffer that will be allocated with string containg serialized options. |
| 889 | * Buffer must be freed by the caller when is no longer needed. |
| 890 | * @param[in] key_val_sep character used to separate key from value |
| 891 | * @param[in] pairs_sep character used to separate two pairs from each other |
| 892 | * @return >= 0 on success, negative on error |
| 893 | * @warning Separators cannot be neither '\\' nor '\0'. They also cannot be the same. |
| 894 | */ |
| 895 | int av_opt_serialize(void *obj, int opt_flags, int flags, char **buffer, |
| 896 | const char key_val_sep, const char pairs_sep); |
| 897 | /** |
| 898 | * @} |
| 899 | */ |
| 900 | |
| 901 | #endif /* AVUTIL_OPT_H */ |