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