FFmpeg
opt.h
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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  * const 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_mallocz(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_iterate() 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_iterate(void **iter)
146  * {
147  * const AVClass *c = *iter ? NULL : &child_class;
148  * *iter = (void*)(uintptr_t)c;
149  * return c;
150  * }
151  * @endcode
152  * Putting child_next() and child_class_iterate() as defined above into
153  * test_class will now make child_struct's options accessible through
154  * test_struct (again, proper setup as described above needs to be done on
155  * child_struct right after it is created).
156  *
157  * From the above example it might not be clear why both child_next()
158  * and child_class_iterate() are needed. The distinction is that child_next()
159  * iterates over actually existing objects, while child_class_iterate()
160  * iterates over all possible child classes. E.g. if an AVCodecContext
161  * was initialized to use a codec which has private options, then its
162  * child_next() will return AVCodecContext.priv_data and finish
163  * iterating. OTOH child_class_iterate() on AVCodecContext.av_class will
164  * iterate over all available codecs with private options.
165  *
166  * @subsection avoptions_implement_named_constants Named constants
167  * It is possible to create named constants for options. Simply set the unit
168  * field of the option the constants should apply to a string and
169  * create the constants themselves as options of type AV_OPT_TYPE_CONST
170  * with their unit field set to the same string.
171  * Their default_val field should contain the value of the named
172  * constant.
173  * For example, to add some named constants for the test_flags option
174  * above, put the following into the child_opts array:
175  * @code
176  * { "test_flags", "This is a test option of flags type.",
177  * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX, "test_unit" },
178  * { "flag1", "This is a flag with value 16", 0, AV_OPT_TYPE_CONST, { .i64 = 16 }, 0, 0, "test_unit" },
179  * @endcode
180  *
181  * @section avoptions_use Using AVOptions
182  * This section deals with accessing options in an AVOptions-enabled struct.
183  * Such structs in FFmpeg are e.g. AVCodecContext in libavcodec or
184  * AVFormatContext in libavformat.
185  *
186  * @subsection avoptions_use_examine Examining AVOptions
187  * The basic functions for examining options are av_opt_next(), which iterates
188  * over all options defined for one object, and av_opt_find(), which searches
189  * for an option with the given name.
190  *
191  * The situation is more complicated with nesting. An AVOptions-enabled struct
192  * may have AVOptions-enabled children. Passing the AV_OPT_SEARCH_CHILDREN flag
193  * to av_opt_find() will make the function search children recursively.
194  *
195  * For enumerating there are basically two cases. The first is when you want to
196  * get all options that may potentially exist on the struct and its children
197  * (e.g. when constructing documentation). In that case you should call
198  * av_opt_child_class_iterate() recursively on the parent struct's AVClass. The
199  * second case is when you have an already initialized struct with all its
200  * children and you want to get all options that can be actually written or read
201  * from it. In that case you should call av_opt_child_next() recursively (and
202  * av_opt_next() on each result).
203  *
204  * @subsection avoptions_use_get_set Reading and writing AVOptions
205  * When setting options, you often have a string read directly from the
206  * user. In such a case, simply passing it to av_opt_set() is enough. For
207  * non-string type options, av_opt_set() will parse the string according to the
208  * option type.
209  *
210  * Similarly av_opt_get() will read any option type and convert it to a string
211  * which will be returned. Do not forget that the string is allocated, so you
212  * have to free it with av_free().
213  *
214  * In some cases it may be more convenient to put all options into an
215  * AVDictionary and call av_opt_set_dict() on it. A specific case of this
216  * are the format/codec open functions in lavf/lavc which take a dictionary
217  * filled with option as a parameter. This makes it possible to set some options
218  * that cannot be set otherwise, since e.g. the input file format is not known
219  * before the file is actually opened.
220  */
221 
230  AV_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length
234  AV_OPT_TYPE_IMAGE_SIZE, ///< offset must point to two consecutive integers
237  AV_OPT_TYPE_VIDEO_RATE, ///< offset must point to AVRational
242 };
243 
244 /**
245  * AVOption
246  */
247 typedef struct AVOption {
248  const char *name;
249 
250  /**
251  * short English help text
252  * @todo What about other languages?
253  */
254  const char *help;
255 
256  /**
257  * The offset relative to the context structure where the option
258  * value is stored. It should be 0 for named constants.
259  */
260  int offset;
262 
263  /**
264  * the default value for scalar options
265  */
266  union {
267  int64_t i64;
268  double dbl;
269  const char *str;
270  /* TODO those are unused now */
272  } default_val;
273  double min; ///< minimum valid value for the option
274  double max; ///< maximum valid value for the option
275 
276  int flags;
277 #define AV_OPT_FLAG_ENCODING_PARAM 1 ///< a generic parameter which can be set by the user for muxing or encoding
278 #define AV_OPT_FLAG_DECODING_PARAM 2 ///< a generic parameter which can be set by the user for demuxing or decoding
279 #define AV_OPT_FLAG_AUDIO_PARAM 8
280 #define AV_OPT_FLAG_VIDEO_PARAM 16
281 #define AV_OPT_FLAG_SUBTITLE_PARAM 32
282 /**
283  * The option is intended for exporting values to the caller.
284  */
285 #define AV_OPT_FLAG_EXPORT 64
286 /**
287  * The option may not be set through the AVOptions API, only read.
288  * This flag only makes sense when AV_OPT_FLAG_EXPORT is also set.
289  */
290 #define AV_OPT_FLAG_READONLY 128
291 #define AV_OPT_FLAG_BSF_PARAM (1<<8) ///< a generic parameter which can be set by the user for bit stream filtering
292 #define AV_OPT_FLAG_RUNTIME_PARAM (1<<15) ///< a generic parameter which can be set by the user at runtime
293 #define AV_OPT_FLAG_FILTERING_PARAM (1<<16) ///< a generic parameter which can be set by the user for filtering
294 #define AV_OPT_FLAG_DEPRECATED (1<<17) ///< set if option is deprecated, users should refer to AVOption.help text for more information
295 #define AV_OPT_FLAG_CHILD_CONSTS (1<<18) ///< set if option constants can also reside in child objects
296 //FIXME think about enc-audio, ... style flags
297 
298  /**
299  * The logical unit to which the option belongs. Non-constant
300  * options and corresponding named constants share the same
301  * unit. May be NULL.
302  */
303  const char *unit;
304 } AVOption;
305 
306 /**
307  * A single allowed range of values, or a single allowed value.
308  */
309 typedef struct AVOptionRange {
310  const char *str;
311  /**
312  * Value range.
313  * For string ranges this represents the min/max length.
314  * For dimensions this represents the min/max pixel count or width/height in multi-component case.
315  */
317  /**
318  * Value's component range.
319  * For string this represents the unicode range for chars, 0-127 limits to ASCII.
320  */
322  /**
323  * Range flag.
324  * If set to 1 the struct encodes a range, if set to 0 a single value.
325  */
326  int is_range;
327 } AVOptionRange;
328 
329 /**
330  * List of AVOptionRange structs.
331  */
332 typedef struct AVOptionRanges {
333  /**
334  * Array of option ranges.
335  *
336  * Most of option types use just one component.
337  * Following describes multi-component option types:
338  *
339  * AV_OPT_TYPE_IMAGE_SIZE:
340  * component index 0: range of pixel count (width * height).
341  * component index 1: range of width.
342  * component index 2: range of height.
343  *
344  * @note To obtain multi-component version of this structure, user must
345  * provide AV_OPT_MULTI_COMPONENT_RANGE to av_opt_query_ranges or
346  * av_opt_query_ranges_default function.
347  *
348  * Multi-component range can be read as in following example:
349  *
350  * @code
351  * int range_index, component_index;
352  * AVOptionRanges *ranges;
353  * AVOptionRange *range[3]; //may require more than 3 in the future.
354  * av_opt_query_ranges(&ranges, obj, key, AV_OPT_MULTI_COMPONENT_RANGE);
355  * for (range_index = 0; range_index < ranges->nb_ranges; range_index++) {
356  * for (component_index = 0; component_index < ranges->nb_components; component_index++)
357  * range[component_index] = ranges->range[ranges->nb_ranges * component_index + range_index];
358  * //do something with range here.
359  * }
360  * av_opt_freep_ranges(&ranges);
361  * @endcode
362  */
364  /**
365  * Number of ranges per component.
366  */
368  /**
369  * Number of componentes.
370  */
373 
374 /**
375  * Show the obj options.
376  *
377  * @param req_flags requested flags for the options to show. Show only the
378  * options for which it is opt->flags & req_flags.
379  * @param rej_flags rejected flags for the options to show. Show only the
380  * options for which it is !(opt->flags & req_flags).
381  * @param av_log_obj log context to use for showing the options
382  */
383 int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags);
384 
385 /**
386  * Set the values of all AVOption fields to their default values.
387  *
388  * @param s an AVOption-enabled struct (its first member must be a pointer to AVClass)
389  */
390 void av_opt_set_defaults(void *s);
391 
392 /**
393  * Set the values of all AVOption fields to their default values. Only these
394  * AVOption fields for which (opt->flags & mask) == flags will have their
395  * default applied to s.
396  *
397  * @param s an AVOption-enabled struct (its first member must be a pointer to AVClass)
398  * @param mask combination of AV_OPT_FLAG_*
399  * @param flags combination of AV_OPT_FLAG_*
400  */
401 void av_opt_set_defaults2(void *s, int mask, int flags);
402 
403 /**
404  * Parse the key/value pairs list in opts. For each key/value pair
405  * found, stores the value in the field in ctx that is named like the
406  * key. ctx must be an AVClass context, storing is done using
407  * AVOptions.
408  *
409  * @param opts options string to parse, may be NULL
410  * @param key_val_sep a 0-terminated list of characters used to
411  * separate key from value
412  * @param pairs_sep a 0-terminated list of characters used to separate
413  * two pairs from each other
414  * @return the number of successfully set key/value pairs, or a negative
415  * value corresponding to an AVERROR code in case of error:
416  * AVERROR(EINVAL) if opts cannot be parsed,
417  * the error code issued by av_opt_set() if a key/value pair
418  * cannot be set
419  */
420 int av_set_options_string(void *ctx, const char *opts,
421  const char *key_val_sep, const char *pairs_sep);
422 
423 /**
424  * Parse the key-value pairs list in opts. For each key=value pair found,
425  * set the value of the corresponding option in ctx.
426  *
427  * @param ctx the AVClass object to set options on
428  * @param opts the options string, key-value pairs separated by a
429  * delimiter
430  * @param shorthand a NULL-terminated array of options names for shorthand
431  * notation: if the first field in opts has no key part,
432  * the key is taken from the first element of shorthand;
433  * then again for the second, etc., until either opts is
434  * finished, shorthand is finished or a named option is
435  * found; after that, all options must be named
436  * @param key_val_sep a 0-terminated list of characters used to separate
437  * key from value, for example '='
438  * @param pairs_sep a 0-terminated list of characters used to separate
439  * two pairs from each other, for example ':' or ','
440  * @return the number of successfully set key=value pairs, or a negative
441  * value corresponding to an AVERROR code in case of error:
442  * AVERROR(EINVAL) if opts cannot be parsed,
443  * the error code issued by av_set_string3() if a key/value pair
444  * cannot be set
445  *
446  * Options names must use only the following characters: a-z A-Z 0-9 - . / _
447  * Separators must use characters distinct from option names and from each
448  * other.
449  */
450 int av_opt_set_from_string(void *ctx, const char *opts,
451  const char *const *shorthand,
452  const char *key_val_sep, const char *pairs_sep);
453 /**
454  * Free all allocated objects in obj.
455  */
456 void av_opt_free(void *obj);
457 
458 /**
459  * Check whether a particular flag is set in a flags field.
460  *
461  * @param field_name the name of the flag field option
462  * @param flag_name the name of the flag to check
463  * @return non-zero if the flag is set, zero if the flag isn't set,
464  * isn't of the right type, or the flags field doesn't exist.
465  */
466 int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name);
467 
468 /**
469  * Set all the options from a given dictionary on an object.
470  *
471  * @param obj a struct whose first element is a pointer to AVClass
472  * @param options options to process. This dictionary will be freed and replaced
473  * by a new one containing all options not found in obj.
474  * Of course this new dictionary needs to be freed by caller
475  * with av_dict_free().
476  *
477  * @return 0 on success, a negative AVERROR if some option was found in obj,
478  * but could not be set.
479  *
480  * @see av_dict_copy()
481  */
482 int av_opt_set_dict(void *obj, struct AVDictionary **options);
483 
484 
485 /**
486  * Set all the options from a given dictionary on an object.
487  *
488  * @param obj a struct whose first element is a pointer to AVClass
489  * @param options options to process. This dictionary will be freed and replaced
490  * by a new one containing all options not found in obj.
491  * Of course this new dictionary needs to be freed by caller
492  * with av_dict_free().
493  * @param search_flags A combination of AV_OPT_SEARCH_*.
494  *
495  * @return 0 on success, a negative AVERROR if some option was found in obj,
496  * but could not be set.
497  *
498  * @see av_dict_copy()
499  */
500 int av_opt_set_dict2(void *obj, struct AVDictionary **options, int search_flags);
501 
502 /**
503  * Extract a key-value pair from the beginning of a string.
504  *
505  * @param ropts pointer to the options string, will be updated to
506  * point to the rest of the string (one of the pairs_sep
507  * or the final NUL)
508  * @param key_val_sep a 0-terminated list of characters used to separate
509  * key from value, for example '='
510  * @param pairs_sep a 0-terminated list of characters used to separate
511  * two pairs from each other, for example ':' or ','
512  * @param flags flags; see the AV_OPT_FLAG_* values below
513  * @param rkey parsed key; must be freed using av_free()
514  * @param rval parsed value; must be freed using av_free()
515  *
516  * @return >=0 for success, or a negative value corresponding to an
517  * AVERROR code in case of error; in particular:
518  * AVERROR(EINVAL) if no key is present
519  *
520  */
521 int av_opt_get_key_value(const char **ropts,
522  const char *key_val_sep, const char *pairs_sep,
523  unsigned flags,
524  char **rkey, char **rval);
525 
526 enum {
527 
528  /**
529  * Accept to parse a value without a key; the key will then be returned
530  * as NULL.
531  */
533 };
534 
535 /**
536  * @defgroup opt_eval_funcs Evaluating option strings
537  * @{
538  * This group of functions can be used to evaluate option strings
539  * and get numbers out of them. They do the same thing as av_opt_set(),
540  * except the result is written into the caller-supplied pointer.
541  *
542  * @param obj a struct whose first element is a pointer to AVClass.
543  * @param o an option for which the string is to be evaluated.
544  * @param val string to be evaluated.
545  * @param *_out value of the string will be written here.
546  *
547  * @return 0 on success, a negative number on failure.
548  */
549 int av_opt_eval_flags (void *obj, const AVOption *o, const char *val, int *flags_out);
550 int av_opt_eval_int (void *obj, const AVOption *o, const char *val, int *int_out);
551 int av_opt_eval_int64 (void *obj, const AVOption *o, const char *val, int64_t *int64_out);
552 int av_opt_eval_float (void *obj, const AVOption *o, const char *val, float *float_out);
553 int av_opt_eval_double(void *obj, const AVOption *o, const char *val, double *double_out);
554 int av_opt_eval_q (void *obj, const AVOption *o, const char *val, AVRational *q_out);
555 /**
556  * @}
557  */
558 
559 #define AV_OPT_SEARCH_CHILDREN (1 << 0) /**< Search in possible children of the
560  given object first. */
561 /**
562  * The obj passed to av_opt_find() is fake -- only a double pointer to AVClass
563  * instead of a required pointer to a struct containing AVClass. This is
564  * useful for searching for options without needing to allocate the corresponding
565  * object.
566  */
567 #define AV_OPT_SEARCH_FAKE_OBJ (1 << 1)
568 
569 /**
570  * In av_opt_get, return NULL if the option has a pointer type and is set to NULL,
571  * rather than returning an empty string.
572  */
573 #define AV_OPT_ALLOW_NULL (1 << 2)
574 
575 /**
576  * Allows av_opt_query_ranges and av_opt_query_ranges_default to return more than
577  * one component for certain option types.
578  * @see AVOptionRanges for details.
579  */
580 #define AV_OPT_MULTI_COMPONENT_RANGE (1 << 12)
581 
582 /**
583  * Look for an option in an object. Consider only options which
584  * have all the specified flags set.
585  *
586  * @param[in] obj A pointer to a struct whose first element is a
587  * pointer to an AVClass.
588  * Alternatively a double pointer to an AVClass, if
589  * AV_OPT_SEARCH_FAKE_OBJ search flag is set.
590  * @param[in] name The name of the option to look for.
591  * @param[in] unit When searching for named constants, name of the unit
592  * it belongs to.
593  * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG).
594  * @param search_flags A combination of AV_OPT_SEARCH_*.
595  *
596  * @return A pointer to the option found, or NULL if no option
597  * was found.
598  *
599  * @note Options found with AV_OPT_SEARCH_CHILDREN flag may not be settable
600  * directly with av_opt_set(). Use special calls which take an options
601  * AVDictionary (e.g. avformat_open_input()) to set options found with this
602  * flag.
603  */
604 const AVOption *av_opt_find(void *obj, const char *name, const char *unit,
605  int opt_flags, int search_flags);
606 
607 /**
608  * Look for an option in an object. Consider only options which
609  * have all the specified flags set.
610  *
611  * @param[in] obj A pointer to a struct whose first element is a
612  * pointer to an AVClass.
613  * Alternatively a double pointer to an AVClass, if
614  * AV_OPT_SEARCH_FAKE_OBJ search flag is set.
615  * @param[in] name The name of the option to look for.
616  * @param[in] unit When searching for named constants, name of the unit
617  * it belongs to.
618  * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG).
619  * @param search_flags A combination of AV_OPT_SEARCH_*.
620  * @param[out] target_obj if non-NULL, an object to which the option belongs will be
621  * written here. It may be different from obj if AV_OPT_SEARCH_CHILDREN is present
622  * in search_flags. This parameter is ignored if search_flags contain
623  * AV_OPT_SEARCH_FAKE_OBJ.
624  *
625  * @return A pointer to the option found, or NULL if no option
626  * was found.
627  */
628 const AVOption *av_opt_find2(void *obj, const char *name, const char *unit,
629  int opt_flags, int search_flags, void **target_obj);
630 
631 /**
632  * Iterate over all AVOptions belonging to obj.
633  *
634  * @param obj an AVOptions-enabled struct or a double pointer to an
635  * AVClass describing it.
636  * @param prev result of the previous call to av_opt_next() on this object
637  * or NULL
638  * @return next AVOption or NULL
639  */
640 const AVOption *av_opt_next(const void *obj, const AVOption *prev);
641 
642 /**
643  * Iterate over AVOptions-enabled children of obj.
644  *
645  * @param prev result of a previous call to this function or NULL
646  * @return next AVOptions-enabled child or NULL
647  */
648 void *av_opt_child_next(void *obj, void *prev);
649 
650 /**
651  * Iterate over potential AVOptions-enabled children of parent.
652  *
653  * @param iter a pointer where iteration state is stored.
654  * @return AVClass corresponding to next potential child or NULL
655  */
656 const AVClass *av_opt_child_class_iterate(const AVClass *parent, void **iter);
657 
658 /**
659  * @defgroup opt_set_funcs Option setting functions
660  * @{
661  * Those functions set the field of obj with the given name to value.
662  *
663  * @param[in] obj A struct whose first element is a pointer to an AVClass.
664  * @param[in] name the name of the field to set
665  * @param[in] val The value to set. In case of av_opt_set() if the field is not
666  * of a string type, then the given string is parsed.
667  * SI postfixes and some named scalars are supported.
668  * If the field is of a numeric type, it has to be a numeric or named
669  * scalar. Behavior with more than one scalar and +- infix operators
670  * is undefined.
671  * If the field is of a flags type, it has to be a sequence of numeric
672  * scalars or named flags separated by '+' or '-'. Prefixing a flag
673  * with '+' causes it to be set without affecting the other flags;
674  * similarly, '-' unsets a flag.
675  * If the field is of a dictionary type, it has to be a ':' separated list of
676  * key=value parameters. Values containing ':' special characters must be
677  * escaped.
678  * @param search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN
679  * is passed here, then the option may be set on a child of obj.
680  *
681  * @return 0 if the value has been set, or an AVERROR code in case of
682  * error:
683  * AVERROR_OPTION_NOT_FOUND if no matching option exists
684  * AVERROR(ERANGE) if the value is out of range
685  * AVERROR(EINVAL) if the value is not valid
686  */
687 int av_opt_set (void *obj, const char *name, const char *val, int search_flags);
688 int av_opt_set_int (void *obj, const char *name, int64_t val, int search_flags);
689 int av_opt_set_double (void *obj, const char *name, double val, int search_flags);
690 int av_opt_set_q (void *obj, const char *name, AVRational val, int search_flags);
691 int av_opt_set_bin (void *obj, const char *name, const uint8_t *val, int size, int search_flags);
692 int av_opt_set_image_size(void *obj, const char *name, int w, int h, int search_flags);
693 int av_opt_set_pixel_fmt (void *obj, const char *name, enum AVPixelFormat fmt, int search_flags);
694 int av_opt_set_sample_fmt(void *obj, const char *name, enum AVSampleFormat fmt, int search_flags);
695 int av_opt_set_video_rate(void *obj, const char *name, AVRational val, int search_flags);
696 int av_opt_set_channel_layout(void *obj, const char *name, int64_t ch_layout, int search_flags);
697 /**
698  * @note Any old dictionary present is discarded and replaced with a copy of the new one. The
699  * caller still owns val is and responsible for freeing it.
700  */
701 int av_opt_set_dict_val(void *obj, const char *name, const AVDictionary *val, int search_flags);
702 
703 /**
704  * Set a binary option to an integer list.
705  *
706  * @param obj AVClass object to set options on
707  * @param name name of the binary option
708  * @param val pointer to an integer list (must have the correct type with
709  * regard to the contents of the list)
710  * @param term list terminator (usually 0 or -1)
711  * @param flags search flags
712  */
713 #define av_opt_set_int_list(obj, name, val, term, flags) \
714  (av_int_list_length(val, term) > INT_MAX / sizeof(*(val)) ? \
715  AVERROR(EINVAL) : \
716  av_opt_set_bin(obj, name, (const uint8_t *)(val), \
717  av_int_list_length(val, term) * sizeof(*(val)), flags))
718 
719 /**
720  * @}
721  */
722 
723 /**
724  * @defgroup opt_get_funcs Option getting functions
725  * @{
726  * Those functions get a value of the option with the given name from an object.
727  *
728  * @param[in] obj a struct whose first element is a pointer to an AVClass.
729  * @param[in] name name of the option to get.
730  * @param[in] search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN
731  * is passed here, then the option may be found in a child of obj.
732  * @param[out] out_val value of the option will be written here
733  * @return >=0 on success, a negative error code otherwise
734  */
735 /**
736  * @note the returned string will be av_malloc()ed and must be av_free()ed by the caller
737  *
738  * @note if AV_OPT_ALLOW_NULL is set in search_flags in av_opt_get, and the
739  * option is of type AV_OPT_TYPE_STRING, AV_OPT_TYPE_BINARY or AV_OPT_TYPE_DICT
740  * and is set to NULL, *out_val will be set to NULL instead of an allocated
741  * empty string.
742  */
743 int av_opt_get (void *obj, const char *name, int search_flags, uint8_t **out_val);
744 int av_opt_get_int (void *obj, const char *name, int search_flags, int64_t *out_val);
745 int av_opt_get_double (void *obj, const char *name, int search_flags, double *out_val);
746 int av_opt_get_q (void *obj, const char *name, int search_flags, AVRational *out_val);
747 int av_opt_get_image_size(void *obj, const char *name, int search_flags, int *w_out, int *h_out);
748 int av_opt_get_pixel_fmt (void *obj, const char *name, int search_flags, enum AVPixelFormat *out_fmt);
749 int av_opt_get_sample_fmt(void *obj, const char *name, int search_flags, enum AVSampleFormat *out_fmt);
750 int av_opt_get_video_rate(void *obj, const char *name, int search_flags, AVRational *out_val);
751 int av_opt_get_channel_layout(void *obj, const char *name, int search_flags, int64_t *ch_layout);
752 /**
753  * @param[out] out_val The returned dictionary is a copy of the actual value and must
754  * be freed with av_dict_free() by the caller
755  */
756 int av_opt_get_dict_val(void *obj, const char *name, int search_flags, AVDictionary **out_val);
757 /**
758  * @}
759  */
760 /**
761  * Gets a pointer to the requested field in a struct.
762  * This function allows accessing a struct even when its fields are moved or
763  * renamed since the application making the access has been compiled,
764  *
765  * @returns a pointer to the field, it can be cast to the correct type and read
766  * or written to.
767  */
768 void *av_opt_ptr(const AVClass *avclass, void *obj, const char *name);
769 
770 /**
771  * Free an AVOptionRanges struct and set it to NULL.
772  */
773 void av_opt_freep_ranges(AVOptionRanges **ranges);
774 
775 /**
776  * Get a list of allowed ranges for the given option.
777  *
778  * The returned list may depend on other fields in obj like for example profile.
779  *
780  * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored
781  * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance
782  * AV_OPT_MULTI_COMPONENT_RANGE indicates that function may return more than one component, @see AVOptionRanges
783  *
784  * The result must be freed with av_opt_freep_ranges.
785  *
786  * @return number of compontents returned on success, a negative errro code otherwise
787  */
788 int av_opt_query_ranges(AVOptionRanges **, void *obj, const char *key, int flags);
789 
790 /**
791  * Copy options from src object into dest object.
792  *
793  * The underlying AVClass of both src and dest must coincide. The guarantee
794  * below does not apply if this is not fulfilled.
795  *
796  * Options that require memory allocation (e.g. string or binary) are malloc'ed in dest object.
797  * Original memory allocated for such options is freed unless both src and dest options points to the same memory.
798  *
799  * Even on error it is guaranteed that allocated options from src and dest
800  * no longer alias each other afterwards; in particular calling av_opt_free()
801  * on both src and dest is safe afterwards if dest has been memdup'ed from src.
802  *
803  * @param dest Object to copy from
804  * @param src Object to copy into
805  * @return 0 on success, negative on error
806  */
807 int av_opt_copy(void *dest, const void *src);
808 
809 /**
810  * Get a default list of allowed ranges for the given option.
811  *
812  * This list is constructed without using the AVClass.query_ranges() callback
813  * and can be used as fallback from within the callback.
814  *
815  * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored
816  * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance
817  * AV_OPT_MULTI_COMPONENT_RANGE indicates that function may return more than one component, @see AVOptionRanges
818  *
819  * The result must be freed with av_opt_free_ranges.
820  *
821  * @return number of compontents returned on success, a negative errro code otherwise
822  */
823 int av_opt_query_ranges_default(AVOptionRanges **, void *obj, const char *key, int flags);
824 
825 /**
826  * Check if given option is set to its default value.
827  *
828  * Options o must belong to the obj. This function must not be called to check child's options state.
829  * @see av_opt_is_set_to_default_by_name().
830  *
831  * @param obj AVClass object to check option on
832  * @param o option to be checked
833  * @return >0 when option is set to its default,
834  * 0 when option is not set its default,
835  * <0 on error
836  */
837 int av_opt_is_set_to_default(void *obj, const AVOption *o);
838 
839 /**
840  * Check if given option is set to its default value.
841  *
842  * @param obj AVClass object to check option on
843  * @param name option name
844  * @param search_flags combination of AV_OPT_SEARCH_*
845  * @return >0 when option is set to its default,
846  * 0 when option is not set its default,
847  * <0 on error
848  */
849 int av_opt_is_set_to_default_by_name(void *obj, const char *name, int search_flags);
850 
851 
852 #define AV_OPT_SERIALIZE_SKIP_DEFAULTS 0x00000001 ///< Serialize options that are not set to default values only.
853 #define AV_OPT_SERIALIZE_OPT_FLAGS_EXACT 0x00000002 ///< Serialize options that exactly match opt_flags only.
854 
855 /**
856  * Serialize object's options.
857  *
858  * Create a string containing object's serialized options.
859  * Such string may be passed back to av_opt_set_from_string() in order to restore option values.
860  * A key/value or pairs separator occurring in the serialized value or
861  * name string are escaped through the av_escape() function.
862  *
863  * @param[in] obj AVClass object to serialize
864  * @param[in] opt_flags serialize options with all the specified flags set (AV_OPT_FLAG)
865  * @param[in] flags combination of AV_OPT_SERIALIZE_* flags
866  * @param[out] buffer Pointer to buffer that will be allocated with string containg serialized options.
867  * Buffer must be freed by the caller when is no longer needed.
868  * @param[in] key_val_sep character used to separate key from value
869  * @param[in] pairs_sep character used to separate two pairs from each other
870  * @return >= 0 on success, negative on error
871  * @warning Separators cannot be neither '\\' nor '\0'. They also cannot be the same.
872  */
873 int av_opt_serialize(void *obj, int opt_flags, int flags, char **buffer,
874  const char key_val_sep, const char pairs_sep);
875 /**
876  * @}
877  */
878 
879 #endif /* AVUTIL_OPT_H */
AVOptionRange::is_range
int is_range
Range flag.
Definition: opt.h:326
av_opt_get_dict_val
int av_opt_get_dict_val(void *obj, const char *name, int search_flags, AVDictionary **out_val)
Definition: opt.c:1037
av_opt_set_image_size
int av_opt_set_image_size(void *obj, const char *name, int w, int h, int search_flags)
Definition: opt.c:634
AVOption::i64
int64_t i64
Definition: opt.h:267
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
name
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option name
Definition: writing_filters.txt:88
AVOptionRanges::nb_components
int nb_components
Number of componentes.
Definition: opt.h:371
AV_OPT_FLAG_IMPLICIT_KEY
@ AV_OPT_FLAG_IMPLICIT_KEY
Accept to parse a value without a key; the key will then be returned as NULL.
Definition: opt.h:532
AV_OPT_TYPE_SAMPLE_FMT
@ AV_OPT_TYPE_SAMPLE_FMT
Definition: opt.h:236
av_opt_set_defaults
void av_opt_set_defaults(void *s)
Set the values of all AVOption fields to their default values.
Definition: opt.c:1364
AVOptionRange::value_max
double value_max
Definition: opt.h:316
AVOptionType
AVOptionType
Definition: opt.h:222
av_opt_ptr
void * av_opt_ptr(const AVClass *avclass, void *obj, const char *name)
Gets a pointer to the requested field in a struct.
Definition: opt.c:1732
AV_OPT_TYPE_VIDEO_RATE
@ AV_OPT_TYPE_VIDEO_RATE
offset must point to AVRational
Definition: opt.h:237
rational.h
AVOptionRange::value_min
double value_min
Value range.
Definition: opt.h:316
AVOptionRanges::nb_ranges
int nb_ranges
Number of ranges per component.
Definition: opt.h:367
w
uint8_t w
Definition: llviddspenc.c:38
av_opt_is_set_to_default_by_name
int av_opt_is_set_to_default_by_name(void *obj, const char *name, int search_flags)
Check if given option is set to its default value.
Definition: opt.c:2053
av_opt_set_double
int av_opt_set_double(void *obj, const char *name, double val, int search_flags)
Definition: opt.c:594
AVOption
AVOption.
Definition: opt.h:247
AV_OPT_TYPE_DURATION
@ AV_OPT_TYPE_DURATION
Definition: opt.h:238
av_opt_is_set_to_default
int av_opt_is_set_to_default(void *obj, const AVOption *o)
Check if given option is set to its default value.
Definition: opt.c:1942
AVOption::help
const char * help
short English help text
Definition: opt.h:254
AVOption::flags
int flags
Definition: opt.h:276
AVDictionary
Definition: dict.c:30
AV_OPT_TYPE_RATIONAL
@ AV_OPT_TYPE_RATIONAL
Definition: opt.h:229
av_set_options_string
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.
Definition: opt.c:1485
AV_OPT_TYPE_BINARY
@ AV_OPT_TYPE_BINARY
offset must point to a pointer immediately followed by an int for the length
Definition: opt.h:230
AVOption::offset
int offset
The offset relative to the context structure where the option value is stored.
Definition: opt.h:260
samplefmt.h
val
static double val(void *priv, double ch)
Definition: aeval.c:76
av_opt_set
int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
Definition: opt.c:468
av_opt_get_channel_layout
int av_opt_get_channel_layout(void *obj, const char *name, int search_flags, int64_t *ch_layout)
Definition: opt.c:1020
mask
static const uint16_t mask[17]
Definition: lzw.c:38
av_opt_set_dict
int av_opt_set_dict(void *obj, struct AVDictionary **options)
Set all the options from a given dictionary on an object.
Definition: opt.c:1661
s
#define s(width, name)
Definition: cbs_vp9.c:257
AV_OPT_TYPE_DOUBLE
@ AV_OPT_TYPE_DOUBLE
Definition: opt.h:226
AVOptionRange::str
const char * str
Definition: opt.h:310
av_opt_set_dict_val
int av_opt_set_dict_val(void *obj, const char *name, const AVDictionary *val, int search_flags)
Definition: opt.c:728
av_opt_set_pixel_fmt
int av_opt_set_pixel_fmt(void *obj, const char *name, enum AVPixelFormat fmt, int search_flags)
Definition: opt.c:702
AV_OPT_TYPE_INT64
@ AV_OPT_TYPE_INT64
Definition: opt.h:225
av_opt_eval_int64
int av_opt_eval_int64(void *obj, const AVOption *o, const char *val, int64_t *int64_out)
ctx
AVFormatContext * ctx
Definition: movenc.c:48
key
const char * key
Definition: hwcontext_opencl.c:168
av_opt_get_pixel_fmt
int av_opt_get_pixel_fmt(void *obj, const char *name, int search_flags, enum AVPixelFormat *out_fmt)
Definition: opt.c:1010
av_opt_find
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.
Definition: opt.c:1666
av_opt_get_video_rate
int av_opt_get_video_rate(void *obj, const char *name, int search_flags, AVRational *out_val)
Definition: opt.c:976
opts
AVDictionary * opts
Definition: movenc.c:50
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
av_opt_set_video_rate
int av_opt_set_video_rate(void *obj, const char *name, AVRational val, int search_flags)
Definition: opt.c:656
av_opt_set_bin
int av_opt_set_bin(void *obj, const char *name, const uint8_t *val, int size, int search_flags)
Definition: opt.c:604
av_opt_get_double
int av_opt_get_double(void *obj, const char *name, int search_flags, double *out_val)
Definition: opt.c:930
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AV_OPT_TYPE_COLOR
@ AV_OPT_TYPE_COLOR
Definition: opt.h:239
av_opt_set_from_string
int av_opt_set_from_string(void *ctx, const char *opts, const char *const *shorthand, const char *key_val_sep, const char *pairs_sep)
Parse the key-value pairs list in opts.
Definition: opt.c:1565
AV_OPT_TYPE_IMAGE_SIZE
@ AV_OPT_TYPE_IMAGE_SIZE
offset must point to two consecutive integers
Definition: opt.h:234
AV_OPT_TYPE_DICT
@ AV_OPT_TYPE_DICT
Definition: opt.h:231
src
#define src
Definition: vp8dsp.c:255
AVOptionRange::component_min
double component_min
Value's component range.
Definition: opt.h:321
av_opt_get_sample_fmt
int av_opt_get_sample_fmt(void *obj, const char *name, int search_flags, enum AVSampleFormat *out_fmt)
Definition: opt.c:1015
av_opt_free
void av_opt_free(void *obj)
Free all allocated objects in obj.
Definition: opt.c:1617
AVOptionRanges::range
AVOptionRange ** range
Array of option ranges.
Definition: opt.h:363
AVOption::min
double min
minimum valid value for the option
Definition: opt.h:273
av_opt_get_int
int av_opt_get_int(void *obj, const char *name, int search_flags, int64_t *out_val)
Definition: opt.c:915
av_opt_set_int
int av_opt_set_int(void *obj, const char *name, int64_t val, int search_flags)
Definition: opt.c:589
options
const OptionDef options[]
av_opt_set_channel_layout
int av_opt_set_channel_layout(void *obj, const char *name, int64_t ch_layout, int search_flags)
Definition: opt.c:712
AVOptionRange
A single allowed range of values, or a single allowed value.
Definition: opt.h:309
size
int size
Definition: twinvq_data.h:10344
av_opt_set_defaults2
void av_opt_set_defaults2(void *s, int mask, int flags)
Set the values of all AVOption fields to their default values.
Definition: opt.c:1369
AVOption::name
const char * name
Definition: opt.h:248
AV_OPT_TYPE_CHANNEL_LAYOUT
@ AV_OPT_TYPE_CHANNEL_LAYOUT
Definition: opt.h:240
av_opt_eval_q
int av_opt_eval_q(void *obj, const AVOption *o, const char *val, AVRational *q_out)
av_opt_find2
const AVOption * av_opt_find2(void *obj, const char *name, const char *unit, int opt_flags, int search_flags, void **target_obj)
Look for an option in an object.
Definition: opt.c:1672
av_opt_set_dict2
int av_opt_set_dict2(void *obj, struct AVDictionary **options, int search_flags)
Set all the options from a given dictionary on an object.
Definition: opt.c:1637
AVOption::q
AVRational q
Definition: opt.h:271
AV_OPT_TYPE_FLOAT
@ AV_OPT_TYPE_FLOAT
Definition: opt.h:227
log.h
AVOption::str
const char * str
Definition: opt.h:269
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
AVOptionRanges
List of AVOptionRange structs.
Definition: opt.h:332
av_opt_next
const AVOption * av_opt_next(const void *obj, const AVOption *prev)
Iterate over all AVOptions belonging to obj.
Definition: opt.c:45
av_opt_eval_double
int av_opt_eval_double(void *obj, const AVOption *o, const char *val, double *double_out)
av_opt_eval_flags
int av_opt_eval_flags(void *obj, const AVOption *o, const char *val, int *flags_out)
AVOption::dbl
double dbl
Definition: opt.h:268
pixfmt.h
av_opt_eval_int
int av_opt_eval_int(void *obj, const AVOption *o, const char *val, int *int_out)
av_opt_get_key_value
int av_opt_get_key_value(const char **ropts, const char *key_val_sep, const char *pairs_sep, unsigned flags, char **rkey, char **rval)
Extract a key-value pair from the beginning of a string.
Definition: opt.c:1543
dict.h
AVOption::type
enum AVOptionType type
Definition: opt.h:261
av_opt_child_class_iterate
const AVClass * av_opt_child_class_iterate(const AVClass *parent, void **iter)
Iterate over potential AVOptions-enabled children of parent.
Definition: opt.c:1725
buffer
the frame and frame reference mechanism is intended to as much as expensive copies of that data while still allowing the filters to produce correct results The data is stored in buffers represented by AVFrame structures Several references can point to the same frame buffer
Definition: filter_design.txt:49
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:224
AV_OPT_TYPE_PIXEL_FMT
@ AV_OPT_TYPE_PIXEL_FMT
Definition: opt.h:235
av_opt_serialize
int av_opt_serialize(void *obj, int opt_flags, int flags, char **buffer, const char key_val_sep, const char pairs_sep)
Serialize object's options.
Definition: opt.c:2065
av_opt_flag_is_set
int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name)
Check whether a particular flag is set in a flags field.
Definition: opt.c:1054
av_opt_query_ranges_default
int av_opt_query_ranges_default(AVOptionRanges **, void *obj, const char *key, int flags)
Get a default list of allowed ranges for the given option.
Definition: opt.c:1851
av_opt_query_ranges
int av_opt_query_ranges(AVOptionRanges **, void *obj, const char *key, int flags)
Get a list of allowed ranges for the given option.
Definition: opt.c:1833
av_opt_eval_float
int av_opt_eval_float(void *obj, const AVOption *o, const char *val, float *float_out)
avutil.h
AVOption::unit
const char * unit
The logical unit to which the option belongs.
Definition: opt.h:303
av_opt_freep_ranges
void av_opt_freep_ranges(AVOptionRanges **ranges)
Free an AVOptionRanges struct and set it to NULL.
Definition: opt.c:1923
av_opt_copy
int av_opt_copy(void *dest, const void *src)
Copy options from src object into dest object.
Definition: opt.c:1775
AVOptionRange::component_max
double component_max
Definition: opt.h:321
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Definition: opt.h:241
AV_OPT_TYPE_FLAGS
@ AV_OPT_TYPE_FLAGS
Definition: opt.h:223
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
av_opt_get
int av_opt_get(void *obj, const char *name, int search_flags, uint8_t **out_val)
Definition: opt.c:782
h
h
Definition: vp9dsp_template.c:2038
av_opt_get_image_size
int av_opt_get_image_size(void *obj, const char *name, int search_flags, int *w_out, int *h_out)
Definition: opt.c:958
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Definition: opt.h:228
av_opt_set_q
int av_opt_set_q(void *obj, const char *name, AVRational val, int search_flags)
Definition: opt.c:599
av_opt_set_sample_fmt
int av_opt_set_sample_fmt(void *obj, const char *name, enum AVSampleFormat fmt, int search_flags)
Definition: opt.c:707
av_opt_show2
int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags)
Show the obj options.
Definition: opt.c:1352
AVOption::max
double max
maximum valid value for the option
Definition: opt.h:274
AV_OPT_TYPE_CONST
@ AV_OPT_TYPE_CONST
Definition: opt.h:233
av_opt_child_next
void * av_opt_child_next(void *obj, void *prev)
Iterate over AVOptions-enabled children of obj.
Definition: opt.c:1717
AVOption::default_val
union AVOption::@310 default_val
the default value for scalar options
AV_OPT_TYPE_UINT64
@ AV_OPT_TYPE_UINT64
Definition: opt.h:232
av_opt_get_q
int av_opt_get_q(void *obj, const char *name, int search_flags, AVRational *out_val)
Definition: opt.c:942