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 "channel_layout.h"
33 #include "dict.h"
34 #include "log.h"
35 #include "pixfmt.h"
36 #include "samplefmt.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  * There are two modes of access to members of AVOption and its child structs.
47  * One is called 'native access', and refers to access from the code that
48  * declares the AVOption in question. The other is 'foreign access', and refers
49  * to access from other code.
50  *
51  * Certain struct members in this header are documented as 'native access only'
52  * or similar - it means that only the code that declared the AVOption in
53  * question is allowed to access the field. This allows us to extend the
54  * semantics of those fields without breaking API compatibility.
55  *
56  * @section avoptions_implement Implementing AVOptions
57  * This section describes how to add AVOptions capabilities to a struct.
58  *
59  * All AVOptions-related information is stored in an AVClass. Therefore
60  * the first member of the struct should be a pointer to an AVClass describing it.
61  * The option field of the AVClass must be set to a NULL-terminated static array
62  * of AVOptions. Each AVOption must have a non-empty name, a type, a default
63  * value and for number-type AVOptions also a range of allowed values. It must
64  * also declare an offset in bytes from the start of the struct, where the field
65  * associated with this AVOption is located. Other fields in the AVOption struct
66  * should also be set when applicable, but are not required.
67  *
68  * The following example illustrates an AVOptions-enabled struct:
69  * @code
70  * typedef struct test_struct {
71  * const AVClass *class;
72  * int int_opt;
73  * char *str_opt;
74  * uint8_t *bin_opt;
75  * int bin_len;
76  * } test_struct;
77  *
78  * static const AVOption test_options[] = {
79  * { "test_int", "This is a test option of int type.", offsetof(test_struct, int_opt),
80  * AV_OPT_TYPE_INT, { .i64 = -1 }, INT_MIN, INT_MAX },
81  * { "test_str", "This is a test option of string type.", offsetof(test_struct, str_opt),
82  * AV_OPT_TYPE_STRING },
83  * { "test_bin", "This is a test option of binary type.", offsetof(test_struct, bin_opt),
84  * AV_OPT_TYPE_BINARY },
85  * { NULL },
86  * };
87  *
88  * static const AVClass test_class = {
89  * .class_name = "test class",
90  * .item_name = av_default_item_name,
91  * .option = test_options,
92  * .version = LIBAVUTIL_VERSION_INT,
93  * };
94  * @endcode
95  *
96  * Next, when allocating your struct, you must ensure that the AVClass pointer
97  * is set to the correct value. Then, av_opt_set_defaults() can be called to
98  * initialize defaults. After that the struct is ready to be used with the
99  * AVOptions API.
100  *
101  * When cleaning up, you may use the av_opt_free() function to automatically
102  * free all the allocated string and binary options.
103  *
104  * Continuing with the above example:
105  *
106  * @code
107  * test_struct *alloc_test_struct(void)
108  * {
109  * test_struct *ret = av_mallocz(sizeof(*ret));
110  * ret->class = &test_class;
111  * av_opt_set_defaults(ret);
112  * return ret;
113  * }
114  * void free_test_struct(test_struct **foo)
115  * {
116  * av_opt_free(*foo);
117  * av_freep(foo);
118  * }
119  * @endcode
120  *
121  * @subsection avoptions_implement_nesting Nesting
122  * It may happen that an AVOptions-enabled struct contains another
123  * AVOptions-enabled struct as a member (e.g. AVCodecContext in
124  * libavcodec exports generic options, while its priv_data field exports
125  * codec-specific options). In such a case, it is possible to set up the
126  * parent struct to export a child's options. To do that, simply
127  * implement AVClass.child_next() and AVClass.child_class_iterate() in the
128  * parent struct's AVClass.
129  * Assuming that the test_struct from above now also contains a
130  * child_struct field:
131  *
132  * @code
133  * typedef struct child_struct {
134  * AVClass *class;
135  * int flags_opt;
136  * } child_struct;
137  * static const AVOption child_opts[] = {
138  * { "test_flags", "This is a test option of flags type.",
139  * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX },
140  * { NULL },
141  * };
142  * static const AVClass child_class = {
143  * .class_name = "child class",
144  * .item_name = av_default_item_name,
145  * .option = child_opts,
146  * .version = LIBAVUTIL_VERSION_INT,
147  * };
148  *
149  * void *child_next(void *obj, void *prev)
150  * {
151  * test_struct *t = obj;
152  * if (!prev && t->child_struct)
153  * return t->child_struct;
154  * return NULL
155  * }
156  * const AVClass child_class_iterate(void **iter)
157  * {
158  * const AVClass *c = *iter ? NULL : &child_class;
159  * *iter = (void*)(uintptr_t)c;
160  * return c;
161  * }
162  * @endcode
163  * Putting child_next() and child_class_iterate() as defined above into
164  * test_class will now make child_struct's options accessible through
165  * test_struct (again, proper setup as described above needs to be done on
166  * child_struct right after it is created).
167  *
168  * From the above example it might not be clear why both child_next()
169  * and child_class_iterate() are needed. The distinction is that child_next()
170  * iterates over actually existing objects, while child_class_iterate()
171  * iterates over all possible child classes. E.g. if an AVCodecContext
172  * was initialized to use a codec which has private options, then its
173  * child_next() will return AVCodecContext.priv_data and finish
174  * iterating. OTOH child_class_iterate() on AVCodecContext.av_class will
175  * iterate over all available codecs with private options.
176  *
177  * @subsection avoptions_implement_named_constants Named constants
178  * It is possible to create named constants for options. Simply set the unit
179  * field of the option the constants should apply to a string and
180  * create the constants themselves as options of type AV_OPT_TYPE_CONST
181  * with their unit field set to the same string.
182  * Their default_val field should contain the value of the named
183  * constant.
184  * For example, to add some named constants for the test_flags option
185  * above, put the following into the child_opts array:
186  * @code
187  * { "test_flags", "This is a test option of flags type.",
188  * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX, "test_unit" },
189  * { "flag1", "This is a flag with value 16", 0, AV_OPT_TYPE_CONST, { .i64 = 16 }, 0, 0, "test_unit" },
190  * @endcode
191  *
192  * @section avoptions_use Using AVOptions
193  * This section deals with accessing options in an AVOptions-enabled struct.
194  * Such structs in FFmpeg are e.g. AVCodecContext in libavcodec or
195  * AVFormatContext in libavformat.
196  *
197  * @subsection avoptions_use_examine Examining AVOptions
198  * The basic functions for examining options are av_opt_next(), which iterates
199  * over all options defined for one object, and av_opt_find(), which searches
200  * for an option with the given name.
201  *
202  * The situation is more complicated with nesting. An AVOptions-enabled struct
203  * may have AVOptions-enabled children. Passing the AV_OPT_SEARCH_CHILDREN flag
204  * to av_opt_find() will make the function search children recursively.
205  *
206  * For enumerating there are basically two cases. The first is when you want to
207  * get all options that may potentially exist on the struct and its children
208  * (e.g. when constructing documentation). In that case you should call
209  * av_opt_child_class_iterate() recursively on the parent struct's AVClass. The
210  * second case is when you have an already initialized struct with all its
211  * children and you want to get all options that can be actually written or read
212  * from it. In that case you should call av_opt_child_next() recursively (and
213  * av_opt_next() on each result).
214  *
215  * @subsection avoptions_use_get_set Reading and writing AVOptions
216  * When setting options, you often have a string read directly from the
217  * user. In such a case, simply passing it to av_opt_set() is enough. For
218  * non-string type options, av_opt_set() will parse the string according to the
219  * option type.
220  *
221  * Similarly av_opt_get() will read any option type and convert it to a string
222  * which will be returned. Do not forget that the string is allocated, so you
223  * have to free it with av_free().
224  *
225  * In some cases it may be more convenient to put all options into an
226  * AVDictionary and call av_opt_set_dict() on it. A specific case of this
227  * are the format/codec open functions in lavf/lavc which take a dictionary
228  * filled with option as a parameter. This makes it possible to set some options
229  * that cannot be set otherwise, since e.g. the input file format is not known
230  * before the file is actually opened.
231  */
232 
241  AV_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length
245  AV_OPT_TYPE_IMAGE_SIZE, ///< offset must point to two consecutive integers
248  AV_OPT_TYPE_VIDEO_RATE, ///< offset must point to AVRational
253 
254  /**
255  * May be combined with another regular option type to declare an array
256  * option.
257  *
258  * For array options, @ref AVOption.offset should refer to a pointer
259  * corresponding to the option type. The pointer should be immediately
260  * followed by an unsigned int that will store the number of elements in the
261  * array.
262  */
264 };
265 
266 /**
267  * A generic parameter which can be set by the user for muxing or encoding.
268  */
269 #define AV_OPT_FLAG_ENCODING_PARAM (1 << 0)
270 /**
271  * A generic parameter which can be set by the user for demuxing or decoding.
272  */
273 #define AV_OPT_FLAG_DECODING_PARAM (1 << 1)
274 #define AV_OPT_FLAG_AUDIO_PARAM (1 << 3)
275 #define AV_OPT_FLAG_VIDEO_PARAM (1 << 4)
276 #define AV_OPT_FLAG_SUBTITLE_PARAM (1 << 5)
277 /**
278  * The option is intended for exporting values to the caller.
279  */
280 #define AV_OPT_FLAG_EXPORT (1 << 6)
281 /**
282  * The option may not be set through the AVOptions API, only read.
283  * This flag only makes sense when AV_OPT_FLAG_EXPORT is also set.
284  */
285 #define AV_OPT_FLAG_READONLY (1 << 7)
286 /**
287  * A generic parameter which can be set by the user for bit stream filtering.
288  */
289 #define AV_OPT_FLAG_BSF_PARAM (1 << 8)
290 
291 /**
292  * A generic parameter which can be set by the user at runtime.
293  */
294 #define AV_OPT_FLAG_RUNTIME_PARAM (1 << 15)
295 /**
296  * A generic parameter which can be set by the user for filtering.
297  */
298 #define AV_OPT_FLAG_FILTERING_PARAM (1 << 16)
299 /**
300  * Set if option is deprecated, users should refer to AVOption.help text for
301  * more information.
302  */
303 #define AV_OPT_FLAG_DEPRECATED (1 << 17)
304 /**
305  * Set if option constants can also reside in child objects.
306  */
307 #define AV_OPT_FLAG_CHILD_CONSTS (1 << 18)
308 
309 /**
310  * May be set as default_val for AV_OPT_TYPE_FLAG_ARRAY options.
311  */
312 typedef struct AVOptionArrayDef {
313  /**
314  * Native access only.
315  *
316  * Default value of the option, as would be serialized by av_opt_get() (i.e.
317  * using the value of sep as the separator).
318  */
319  const char *def;
320 
321  /**
322  * Minimum number of elements in the array. When this field is non-zero, def
323  * must be non-NULL and contain at least this number of elements.
324  */
325  unsigned size_min;
326  /**
327  * Maximum number of elements in the array, 0 when unlimited.
328  */
329  unsigned size_max;
330 
331  /**
332  * Separator between array elements in string representations of this
333  * option, used by av_opt_set() and av_opt_get(). It must be a printable
334  * ASCII character, excluding alphanumeric and the backslash. A comma is
335  * used when sep=0.
336  *
337  * The separator and the backslash must be backslash-escaped in order to
338  * appear in string representations of the option value.
339  */
340  char sep;
342 
343 /**
344  * AVOption
345  */
346 typedef struct AVOption {
347  const char *name;
348 
349  /**
350  * short English help text
351  * @todo What about other languages?
352  */
353  const char *help;
354 
355  /**
356  * Native access only.
357  *
358  * The offset relative to the context structure where the option
359  * value is stored. It should be 0 for named constants.
360  */
361  int offset;
363 
364  /**
365  * Native access only, except when documented otherwise.
366  * the default value for scalar options
367  */
368  union {
369  int64_t i64;
370  double dbl;
371  const char *str;
372  /* TODO those are unused now */
374 
375  /**
376  * Used for AV_OPT_TYPE_FLAG_ARRAY options. May be NULL.
377  *
378  * Foreign access to some members allowed, as noted in AVOptionArrayDef
379  * documentation.
380  */
382  } default_val;
383  double min; ///< minimum valid value for the option
384  double max; ///< maximum valid value for the option
385 
386  /**
387  * A combination of AV_OPT_FLAG_*.
388  */
389  int flags;
390 
391  /**
392  * The logical unit to which the option belongs. Non-constant
393  * options and corresponding named constants share the same
394  * unit. May be NULL.
395  */
396  const char *unit;
397 } AVOption;
398 
399 /**
400  * A single allowed range of values, or a single allowed value.
401  */
402 typedef struct AVOptionRange {
403  const char *str;
404  /**
405  * Value range.
406  * For string ranges this represents the min/max length.
407  * For dimensions this represents the min/max pixel count or width/height in multi-component case.
408  */
410  /**
411  * Value's component range.
412  * For string this represents the unicode range for chars, 0-127 limits to ASCII.
413  */
415  /**
416  * Range flag.
417  * If set to 1 the struct encodes a range, if set to 0 a single value.
418  */
419  int is_range;
420 } AVOptionRange;
421 
422 /**
423  * List of AVOptionRange structs.
424  */
425 typedef struct AVOptionRanges {
426  /**
427  * Array of option ranges.
428  *
429  * Most of option types use just one component.
430  * Following describes multi-component option types:
431  *
432  * AV_OPT_TYPE_IMAGE_SIZE:
433  * component index 0: range of pixel count (width * height).
434  * component index 1: range of width.
435  * component index 2: range of height.
436  *
437  * @note To obtain multi-component version of this structure, user must
438  * provide AV_OPT_MULTI_COMPONENT_RANGE to av_opt_query_ranges or
439  * av_opt_query_ranges_default function.
440  *
441  * Multi-component range can be read as in following example:
442  *
443  * @code
444  * int range_index, component_index;
445  * AVOptionRanges *ranges;
446  * AVOptionRange *range[3]; //may require more than 3 in the future.
447  * av_opt_query_ranges(&ranges, obj, key, AV_OPT_MULTI_COMPONENT_RANGE);
448  * for (range_index = 0; range_index < ranges->nb_ranges; range_index++) {
449  * for (component_index = 0; component_index < ranges->nb_components; component_index++)
450  * range[component_index] = ranges->range[ranges->nb_ranges * component_index + range_index];
451  * //do something with range here.
452  * }
453  * av_opt_freep_ranges(&ranges);
454  * @endcode
455  */
457  /**
458  * Number of ranges per component.
459  */
461  /**
462  * Number of componentes.
463  */
466 
467 /**
468  * @defgroup opt_mng AVOption (un)initialization and inspection.
469  * @{
470  */
471 
472 /**
473  * Set the values of all AVOption fields to their default values.
474  *
475  * @param s an AVOption-enabled struct (its first member must be a pointer to AVClass)
476  */
477 void av_opt_set_defaults(void *s);
478 
479 /**
480  * Set the values of all AVOption fields to their default values. Only these
481  * AVOption fields for which (opt->flags & mask) == flags will have their
482  * default applied to s.
483  *
484  * @param s an AVOption-enabled struct (its first member must be a pointer to AVClass)
485  * @param mask combination of AV_OPT_FLAG_*
486  * @param flags combination of AV_OPT_FLAG_*
487  */
488 void av_opt_set_defaults2(void *s, int mask, int flags);
489 
490 /**
491  * Free all allocated objects in obj.
492  */
493 void av_opt_free(void *obj);
494 
495 /**
496  * Iterate over all AVOptions belonging to obj.
497  *
498  * @param obj an AVOptions-enabled struct or a double pointer to an
499  * AVClass describing it.
500  * @param prev result of the previous call to av_opt_next() on this object
501  * or NULL
502  * @return next AVOption or NULL
503  */
504 const AVOption *av_opt_next(const void *obj, const AVOption *prev);
505 
506 /**
507  * Iterate over AVOptions-enabled children of obj.
508  *
509  * @param prev result of a previous call to this function or NULL
510  * @return next AVOptions-enabled child or NULL
511  */
512 void *av_opt_child_next(void *obj, void *prev);
513 
514 /**
515  * Iterate over potential AVOptions-enabled children of parent.
516  *
517  * @param iter a pointer where iteration state is stored.
518  * @return AVClass corresponding to next potential child or NULL
519  */
520 const AVClass *av_opt_child_class_iterate(const AVClass *parent, void **iter);
521 
522 #define AV_OPT_SEARCH_CHILDREN (1 << 0) /**< Search in possible children of the
523  given object first. */
524 /**
525  * The obj passed to av_opt_find() is fake -- only a double pointer to AVClass
526  * instead of a required pointer to a struct containing AVClass. This is
527  * useful for searching for options without needing to allocate the corresponding
528  * object.
529  */
530 #define AV_OPT_SEARCH_FAKE_OBJ (1 << 1)
531 
532 /**
533  * In av_opt_get, return NULL if the option has a pointer type and is set to NULL,
534  * rather than returning an empty string.
535  */
536 #define AV_OPT_ALLOW_NULL (1 << 2)
537 
538 /**
539  * Allows av_opt_query_ranges and av_opt_query_ranges_default to return more than
540  * one component for certain option types.
541  * @see AVOptionRanges for details.
542  */
543 #define AV_OPT_MULTI_COMPONENT_RANGE (1 << 12)
544 
545 /**
546  * Look for an option in an object. Consider only options which
547  * have all the specified flags set.
548  *
549  * @param[in] obj A pointer to a struct whose first element is a
550  * pointer to an AVClass.
551  * Alternatively a double pointer to an AVClass, if
552  * AV_OPT_SEARCH_FAKE_OBJ search flag is set.
553  * @param[in] name The name of the option to look for.
554  * @param[in] unit When searching for named constants, name of the unit
555  * it belongs to.
556  * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG).
557  * @param search_flags A combination of AV_OPT_SEARCH_*.
558  *
559  * @return A pointer to the option found, or NULL if no option
560  * was found.
561  *
562  * @note Options found with AV_OPT_SEARCH_CHILDREN flag may not be settable
563  * directly with av_opt_set(). Use special calls which take an options
564  * AVDictionary (e.g. avformat_open_input()) to set options found with this
565  * flag.
566  */
567 const AVOption *av_opt_find(void *obj, const char *name, const char *unit,
568  int opt_flags, int search_flags);
569 
570 /**
571  * Look for an option in an object. Consider only options which
572  * have all the specified flags set.
573  *
574  * @param[in] obj A pointer to a struct whose first element is a
575  * pointer to an AVClass.
576  * Alternatively a double pointer to an AVClass, if
577  * AV_OPT_SEARCH_FAKE_OBJ search flag is set.
578  * @param[in] name The name of the option to look for.
579  * @param[in] unit When searching for named constants, name of the unit
580  * it belongs to.
581  * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG).
582  * @param search_flags A combination of AV_OPT_SEARCH_*.
583  * @param[out] target_obj if non-NULL, an object to which the option belongs will be
584  * written here. It may be different from obj if AV_OPT_SEARCH_CHILDREN is present
585  * in search_flags. This parameter is ignored if search_flags contain
586  * AV_OPT_SEARCH_FAKE_OBJ.
587  *
588  * @return A pointer to the option found, or NULL if no option
589  * was found.
590  */
591 const AVOption *av_opt_find2(void *obj, const char *name, const char *unit,
592  int opt_flags, int search_flags, void **target_obj);
593 
594 /**
595  * Show the obj options.
596  *
597  * @param req_flags requested flags for the options to show. Show only the
598  * options for which it is opt->flags & req_flags.
599  * @param rej_flags rejected flags for the options to show. Show only the
600  * options for which it is !(opt->flags & req_flags).
601  * @param av_log_obj log context to use for showing the options
602  */
603 int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags);
604 
605 /**
606  * Extract a key-value pair from the beginning of a string.
607  *
608  * @param ropts pointer to the options string, will be updated to
609  * point to the rest of the string (one of the pairs_sep
610  * or the final NUL)
611  * @param key_val_sep a 0-terminated list of characters used to separate
612  * key from value, for example '='
613  * @param pairs_sep a 0-terminated list of characters used to separate
614  * two pairs from each other, for example ':' or ','
615  * @param flags flags; see the AV_OPT_FLAG_* values below
616  * @param rkey parsed key; must be freed using av_free()
617  * @param rval parsed value; must be freed using av_free()
618  *
619  * @return >=0 for success, or a negative value corresponding to an
620  * AVERROR code in case of error; in particular:
621  * AVERROR(EINVAL) if no key is present
622  *
623  */
624 int av_opt_get_key_value(const char **ropts,
625  const char *key_val_sep, const char *pairs_sep,
626  unsigned flags,
627  char **rkey, char **rval);
628 
629 enum {
630 
631  /**
632  * Accept to parse a value without a key; the key will then be returned
633  * as NULL.
634  */
636 };
637 
638 /**
639  * @}
640  */
641 
642 /**
643  * @defgroup opt_write Setting and modifying option values
644  * @{
645  */
646 
647 /**
648  * Parse the key/value pairs list in opts. For each key/value pair
649  * found, stores the value in the field in ctx that is named like the
650  * key. ctx must be an AVClass context, storing is done using
651  * AVOptions.
652  *
653  * @param opts options string to parse, may be NULL
654  * @param key_val_sep a 0-terminated list of characters used to
655  * separate key from value
656  * @param pairs_sep a 0-terminated list of characters used to separate
657  * two pairs from each other
658  * @return the number of successfully set key/value pairs, or a negative
659  * value corresponding to an AVERROR code in case of error:
660  * AVERROR(EINVAL) if opts cannot be parsed,
661  * the error code issued by av_opt_set() if a key/value pair
662  * cannot be set
663  */
664 int av_set_options_string(void *ctx, const char *opts,
665  const char *key_val_sep, const char *pairs_sep);
666 
667 /**
668  * Parse the key-value pairs list in opts. For each key=value pair found,
669  * set the value of the corresponding option in ctx.
670  *
671  * @param ctx the AVClass object to set options on
672  * @param opts the options string, key-value pairs separated by a
673  * delimiter
674  * @param shorthand a NULL-terminated array of options names for shorthand
675  * notation: if the first field in opts has no key part,
676  * the key is taken from the first element of shorthand;
677  * then again for the second, etc., until either opts is
678  * finished, shorthand is finished or a named option is
679  * found; after that, all options must be named
680  * @param key_val_sep a 0-terminated list of characters used to separate
681  * key from value, for example '='
682  * @param pairs_sep a 0-terminated list of characters used to separate
683  * two pairs from each other, for example ':' or ','
684  * @return the number of successfully set key=value pairs, or a negative
685  * value corresponding to an AVERROR code in case of error:
686  * AVERROR(EINVAL) if opts cannot be parsed,
687  * the error code issued by av_set_string3() if a key/value pair
688  * cannot be set
689  *
690  * Options names must use only the following characters: a-z A-Z 0-9 - . / _
691  * Separators must use characters distinct from option names and from each
692  * other.
693  */
694 int av_opt_set_from_string(void *ctx, const char *opts,
695  const char *const *shorthand,
696  const char *key_val_sep, const char *pairs_sep);
697 
698 /**
699  * Set all the options from a given dictionary on an object.
700  *
701  * @param obj a struct whose first element is a pointer to AVClass
702  * @param options options to process. This dictionary will be freed and replaced
703  * by a new one containing all options not found in obj.
704  * Of course this new dictionary needs to be freed by caller
705  * with av_dict_free().
706  *
707  * @return 0 on success, a negative AVERROR if some option was found in obj,
708  * but could not be set.
709  *
710  * @see av_dict_copy()
711  */
712 int av_opt_set_dict(void *obj, struct AVDictionary **options);
713 
714 
715 /**
716  * Set all the options from a given dictionary on an object.
717  *
718  * @param obj a struct whose first element is a pointer to AVClass
719  * @param options options to process. This dictionary will be freed and replaced
720  * by a new one containing all options not found in obj.
721  * Of course this new dictionary needs to be freed by caller
722  * with av_dict_free().
723  * @param search_flags A combination of AV_OPT_SEARCH_*.
724  *
725  * @return 0 on success, a negative AVERROR if some option was found in obj,
726  * but could not be set.
727  *
728  * @see av_dict_copy()
729  */
730 int av_opt_set_dict2(void *obj, struct AVDictionary **options, int search_flags);
731 
732 /**
733  * Copy options from src object into dest object.
734  *
735  * The underlying AVClass of both src and dest must coincide. The guarantee
736  * below does not apply if this is not fulfilled.
737  *
738  * Options that require memory allocation (e.g. string or binary) are malloc'ed in dest object.
739  * Original memory allocated for such options is freed unless both src and dest options points to the same memory.
740  *
741  * Even on error it is guaranteed that allocated options from src and dest
742  * no longer alias each other afterwards; in particular calling av_opt_free()
743  * on both src and dest is safe afterwards if dest has been memdup'ed from src.
744  *
745  * @param dest Object to copy from
746  * @param src Object to copy into
747  * @return 0 on success, negative on error
748  */
749 int av_opt_copy(void *dest, const void *src);
750 
751 /**
752  * @defgroup opt_set_funcs Option setting functions
753  * @{
754  * Those functions set the field of obj with the given name to value.
755  *
756  * @param[in] obj A struct whose first element is a pointer to an AVClass.
757  * @param[in] name the name of the field to set
758  * @param[in] val The value to set. In case of av_opt_set() if the field is not
759  * of a string type, then the given string is parsed.
760  * SI postfixes and some named scalars are supported.
761  * If the field is of a numeric type, it has to be a numeric or named
762  * scalar. Behavior with more than one scalar and +- infix operators
763  * is undefined.
764  * If the field is of a flags type, it has to be a sequence of numeric
765  * scalars or named flags separated by '+' or '-'. Prefixing a flag
766  * with '+' causes it to be set without affecting the other flags;
767  * similarly, '-' unsets a flag.
768  * If the field is of a dictionary type, it has to be a ':' separated list of
769  * key=value parameters. Values containing ':' special characters must be
770  * escaped.
771  * @param search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN
772  * is passed here, then the option may be set on a child of obj.
773  *
774  * @return 0 if the value has been set, or an AVERROR code in case of
775  * error:
776  * AVERROR_OPTION_NOT_FOUND if no matching option exists
777  * AVERROR(ERANGE) if the value is out of range
778  * AVERROR(EINVAL) if the value is not valid
779  */
780 int av_opt_set (void *obj, const char *name, const char *val, int search_flags);
781 int av_opt_set_int (void *obj, const char *name, int64_t val, int search_flags);
782 int av_opt_set_double (void *obj, const char *name, double val, int search_flags);
783 int av_opt_set_q (void *obj, const char *name, AVRational val, int search_flags);
784 int av_opt_set_bin (void *obj, const char *name, const uint8_t *val, int size, int search_flags);
785 int av_opt_set_image_size(void *obj, const char *name, int w, int h, int search_flags);
786 int av_opt_set_pixel_fmt (void *obj, const char *name, enum AVPixelFormat fmt, int search_flags);
787 int av_opt_set_sample_fmt(void *obj, const char *name, enum AVSampleFormat fmt, int search_flags);
788 int av_opt_set_video_rate(void *obj, const char *name, AVRational val, int search_flags);
789 int av_opt_set_chlayout(void *obj, const char *name, const AVChannelLayout *layout, int search_flags);
790 /**
791  * @note Any old dictionary present is discarded and replaced with a copy of the new one. The
792  * caller still owns val is and responsible for freeing it.
793  */
794 int av_opt_set_dict_val(void *obj, const char *name, const AVDictionary *val, int search_flags);
795 
796 /**
797  * Set a binary option to an integer list.
798  *
799  * @param obj AVClass object to set options on
800  * @param name name of the binary option
801  * @param val pointer to an integer list (must have the correct type with
802  * regard to the contents of the list)
803  * @param term list terminator (usually 0 or -1)
804  * @param flags search flags
805  */
806 #define av_opt_set_int_list(obj, name, val, term, flags) \
807  (av_int_list_length(val, term) > INT_MAX / sizeof(*(val)) ? \
808  AVERROR(EINVAL) : \
809  av_opt_set_bin(obj, name, (const uint8_t *)(val), \
810  av_int_list_length(val, term) * sizeof(*(val)), flags))
811 
812 /**
813  * @}
814  * @}
815  */
816 
817 /**
818  * @defgroup opt_read Reading option values
819  * @{
820  */
821 
822 /**
823  * @defgroup opt_get_funcs Option getting functions
824  * @{
825  * Those functions get a value of the option with the given name from an object.
826  *
827  * @param[in] obj a struct whose first element is a pointer to an AVClass.
828  * @param[in] name name of the option to get.
829  * @param[in] search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN
830  * is passed here, then the option may be found in a child of obj.
831  * @param[out] out_val value of the option will be written here
832  * @return >=0 on success, a negative error code otherwise
833  */
834 /**
835  * @note the returned string will be av_malloc()ed and must be av_free()ed by the caller
836  *
837  * @note if AV_OPT_ALLOW_NULL is set in search_flags in av_opt_get, and the
838  * option is of type AV_OPT_TYPE_STRING, AV_OPT_TYPE_BINARY or AV_OPT_TYPE_DICT
839  * and is set to NULL, *out_val will be set to NULL instead of an allocated
840  * empty string.
841  */
842 int av_opt_get (void *obj, const char *name, int search_flags, uint8_t **out_val);
843 int av_opt_get_int (void *obj, const char *name, int search_flags, int64_t *out_val);
844 int av_opt_get_double (void *obj, const char *name, int search_flags, double *out_val);
845 int av_opt_get_q (void *obj, const char *name, int search_flags, AVRational *out_val);
846 int av_opt_get_image_size(void *obj, const char *name, int search_flags, int *w_out, int *h_out);
847 int av_opt_get_pixel_fmt (void *obj, const char *name, int search_flags, enum AVPixelFormat *out_fmt);
848 int av_opt_get_sample_fmt(void *obj, const char *name, int search_flags, enum AVSampleFormat *out_fmt);
849 int av_opt_get_video_rate(void *obj, const char *name, int search_flags, AVRational *out_val);
850 int av_opt_get_chlayout(void *obj, const char *name, int search_flags, AVChannelLayout *layout);
851 /**
852  * @param[out] out_val The returned dictionary is a copy of the actual value and must
853  * be freed with av_dict_free() by the caller
854  */
855 int av_opt_get_dict_val(void *obj, const char *name, int search_flags, AVDictionary **out_val);
856 /**
857  * @}
858  */
859 
860 /**
861  * @defgroup opt_eval_funcs Evaluating option strings
862  * @{
863  * This group of functions can be used to evaluate option strings
864  * and get numbers out of them. They do the same thing as av_opt_set(),
865  * except the result is written into the caller-supplied pointer.
866  *
867  * @param obj a struct whose first element is a pointer to AVClass.
868  * @param o an option for which the string is to be evaluated.
869  * @param val string to be evaluated.
870  * @param *_out value of the string will be written here.
871  *
872  * @return 0 on success, a negative number on failure.
873  */
874 int av_opt_eval_flags (void *obj, const AVOption *o, const char *val, int *flags_out);
875 int av_opt_eval_int (void *obj, const AVOption *o, const char *val, int *int_out);
876 int av_opt_eval_int64 (void *obj, const AVOption *o, const char *val, int64_t *int64_out);
877 int av_opt_eval_float (void *obj, const AVOption *o, const char *val, float *float_out);
878 int av_opt_eval_double(void *obj, const AVOption *o, const char *val, double *double_out);
879 int av_opt_eval_q (void *obj, const AVOption *o, const char *val, AVRational *q_out);
880 /**
881  * @}
882  */
883 
884 /**
885  * Gets a pointer to the requested field in a struct.
886  * This function allows accessing a struct even when its fields are moved or
887  * renamed since the application making the access has been compiled,
888  *
889  * @returns a pointer to the field, it can be cast to the correct type and read
890  * or written to.
891  */
892 void *av_opt_ptr(const AVClass *avclass, void *obj, const char *name);
893 
894 /**
895  * Check if given option is set to its default value.
896  *
897  * Options o must belong to the obj. This function must not be called to check child's options state.
898  * @see av_opt_is_set_to_default_by_name().
899  *
900  * @param obj AVClass object to check option on
901  * @param o option to be checked
902  * @return >0 when option is set to its default,
903  * 0 when option is not set its default,
904  * <0 on error
905  */
906 int av_opt_is_set_to_default(void *obj, const AVOption *o);
907 
908 /**
909  * Check if given option is set to its default value.
910  *
911  * @param obj AVClass object to check option on
912  * @param name option name
913  * @param search_flags combination of AV_OPT_SEARCH_*
914  * @return >0 when option is set to its default,
915  * 0 when option is not set its default,
916  * <0 on error
917  */
918 int av_opt_is_set_to_default_by_name(void *obj, const char *name, int search_flags);
919 
920 /**
921  * Check whether a particular flag is set in a flags field.
922  *
923  * @param field_name the name of the flag field option
924  * @param flag_name the name of the flag to check
925  * @return non-zero if the flag is set, zero if the flag isn't set,
926  * isn't of the right type, or the flags field doesn't exist.
927  */
928 int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name);
929 
930 #define AV_OPT_SERIALIZE_SKIP_DEFAULTS 0x00000001 ///< Serialize options that are not set to default values only.
931 #define AV_OPT_SERIALIZE_OPT_FLAGS_EXACT 0x00000002 ///< Serialize options that exactly match opt_flags only.
932 
933 /**
934  * Serialize object's options.
935  *
936  * Create a string containing object's serialized options.
937  * Such string may be passed back to av_opt_set_from_string() in order to restore option values.
938  * A key/value or pairs separator occurring in the serialized value or
939  * name string are escaped through the av_escape() function.
940  *
941  * @param[in] obj AVClass object to serialize
942  * @param[in] opt_flags serialize options with all the specified flags set (AV_OPT_FLAG)
943  * @param[in] flags combination of AV_OPT_SERIALIZE_* flags
944  * @param[out] buffer Pointer to buffer that will be allocated with string containg serialized options.
945  * Buffer must be freed by the caller when is no longer needed.
946  * @param[in] key_val_sep character used to separate key from value
947  * @param[in] pairs_sep character used to separate two pairs from each other
948  * @return >= 0 on success, negative on error
949  * @warning Separators cannot be neither '\\' nor '\0'. They also cannot be the same.
950  */
951 int av_opt_serialize(void *obj, int opt_flags, int flags, char **buffer,
952  const char key_val_sep, const char pairs_sep);
953 
954 /**
955  * @}
956  */
957 
958 /**
959  * Free an AVOptionRanges struct and set it to NULL.
960  */
961 void av_opt_freep_ranges(AVOptionRanges **ranges);
962 
963 /**
964  * Get a list of allowed ranges for the given option.
965  *
966  * The returned list may depend on other fields in obj like for example profile.
967  *
968  * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored
969  * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance
970  * AV_OPT_MULTI_COMPONENT_RANGE indicates that function may return more than one component, @see AVOptionRanges
971  *
972  * The result must be freed with av_opt_freep_ranges.
973  *
974  * @return number of compontents returned on success, a negative errro code otherwise
975  */
976 int av_opt_query_ranges(AVOptionRanges **, void *obj, const char *key, int flags);
977 
978 /**
979  * Get a default list of allowed ranges for the given option.
980  *
981  * This list is constructed without using the AVClass.query_ranges() callback
982  * and can be used as fallback from within the callback.
983  *
984  * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored
985  * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance
986  * AV_OPT_MULTI_COMPONENT_RANGE indicates that function may return more than one component, @see AVOptionRanges
987  *
988  * The result must be freed with av_opt_free_ranges.
989  *
990  * @return number of compontents returned on success, a negative errro code otherwise
991  */
992 int av_opt_query_ranges_default(AVOptionRanges **, void *obj, const char *key, int flags);
993 
994 /**
995  * @}
996  */
997 
998 #endif /* AVUTIL_OPT_H */
AVOptionRange::is_range
int is_range
Range flag.
Definition: opt.h:419
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:1326
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:836
AVOption::i64
int64_t i64
Definition: opt.h:369
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:71
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:464
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:1640
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:1343
AV_OPT_TYPE_SAMPLE_FMT
@ AV_OPT_TYPE_SAMPLE_FMT
Definition: opt.h:247
AVOptionRange::value_max
double value_max
Definition: opt.h:409
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:2011
AVOptionArrayDef::sep
char sep
Separator between array elements in string representations of this option, used by av_opt_set() and a...
Definition: opt.h:340
AVOptionType
AVOptionType
Definition: opt.h:233
AVOptionArrayDef
May be set as default_val for AV_OPT_TYPE_FLAG_ARRAY options.
Definition: opt.h:312
AV_OPT_TYPE_VIDEO_RATE
@ AV_OPT_TYPE_VIDEO_RATE
offset must point to AVRational
Definition: opt.h:248
rational.h
AVOption::arr
const AVOptionArrayDef * arr
Used for AV_OPT_TYPE_FLAG_ARRAY options.
Definition: opt.h:381
AVOptionRange::value_min
double value_min
Value range.
Definition: opt.h:409
AVOptionRanges::nb_ranges
int nb_ranges
Number of ranges per component.
Definition: opt.h:460
w
uint8_t w
Definition: llviddspenc.c:38
AVOption::default_val
union AVOption::@386 default_val
Native access only, except when documented otherwise.
av_opt_set_double
int av_opt_set_double(void *obj, const char *name, double val, int search_flags)
Definition: opt.c:796
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:1858
AVOption
AVOption.
Definition: opt.h:346
AV_OPT_TYPE_DURATION
@ AV_OPT_TYPE_DURATION
Definition: opt.h:249
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:1958
AVOption::help
const char * help
short English help text
Definition: opt.h:353
AVOption::flags
int flags
A combination of AV_OPT_FLAG_*.
Definition: opt.h:389
AVDictionary
Definition: dict.c:34
AV_OPT_TYPE_RATIONAL
@ AV_OPT_TYPE_RATIONAL
Definition: opt.h:240
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:2389
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:241
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:2244
AVOption::offset
int offset
Native access only.
Definition: opt.h:361
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:1836
samplefmt.h
av_opt_free
void av_opt_free(void *obj)
Free all allocated objects in obj.
Definition: opt.c:1910
val
static double val(void *priv, double ch)
Definition: aeval.c:78
av_opt_set
int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
Definition: opt.c:740
mask
static const uint16_t mask[17]
Definition: lzw.c:38
AVOptionArrayDef::def
const char * def
Native access only.
Definition: opt.h:319
s
#define s(width, name)
Definition: cbs_vp9.c:198
AV_OPT_TYPE_DOUBLE
@ AV_OPT_TYPE_DOUBLE
Definition: opt.h:237
AVOptionRange::str
const char * str
Definition: opt.h:403
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:915
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:905
AV_OPT_TYPE_INT64
@ AV_OPT_TYPE_INT64
Definition: opt.h:236
av_opt_eval_int64
int av_opt_eval_int64(void *obj, const AVOption *o, const char *val, int64_t *int64_out)
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:1778
ctx
AVFormatContext * ctx
Definition: movenc.c:49
key
const char * key
Definition: hwcontext_opencl.c:189
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:1300
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:1266
AVOptionArrayDef::size_max
unsigned size_max
Maximum number of elements in the array, 0 when unlimited.
Definition: opt.h:329
opts
AVDictionary * opts
Definition: movenc.c:51
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:858
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:806
av_opt_get_double
int av_opt_get_double(void *obj, const char *name, int search_flags, double *out_val)
Definition: opt.c:1220
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AV_OPT_TYPE_COLOR
@ AV_OPT_TYPE_COLOR
Definition: opt.h:250
AV_OPT_TYPE_IMAGE_SIZE
@ AV_OPT_TYPE_IMAGE_SIZE
offset must point to two consecutive integers
Definition: opt.h:245
AV_OPT_TYPE_DICT
@ AV_OPT_TYPE_DICT
Definition: opt.h:242
AVOptionRange::component_min
double component_min
Value's component range.
Definition: opt.h:414
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:1305
AVOptionRanges::range
AVOptionRange ** range
Array of option ranges.
Definition: opt.h:456
AVOption::min
double min
minimum valid value for the option
Definition: opt.h:383
AV_OPT_TYPE_CHLAYOUT
@ AV_OPT_TYPE_CHLAYOUT
Definition: opt.h:252
av_opt_get_int
int av_opt_get_int(void *obj, const char *name, int search_flags, int64_t *out_val)
Definition: opt.c:1205
av_opt_set_int
int av_opt_set_int(void *obj, const char *name, int64_t val, int search_flags)
Definition: opt.c:791
av_opt_copy
int av_opt_copy(void *dest, const void *src)
Copy options from src object into dest object.
Definition: opt.c:2110
options
const OptionDef options[]
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:1952
AVOptionRange
A single allowed range of values, or a single allowed value.
Definition: opt.h:402
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:303
AV_OPT_TYPE_FLAG_ARRAY
@ AV_OPT_TYPE_FLAG_ARRAY
May be combined with another regular option type to declare an array option.
Definition: opt.h:263
av_opt_set_chlayout
int av_opt_set_chlayout(void *obj, const char *name, const AVChannelLayout *layout, int search_flags)
Definition: opt.c:934
size
int size
Definition: twinvq_data.h:10344
AVOption::name
const char * name
Definition: opt.h:347
av_opt_eval_q
int av_opt_eval_q(void *obj, const AVOption *o, const char *val, AVRational *q_out)
AVOption::q
AVRational q
Definition: opt.h:373
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:1628
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:2018
AV_OPT_TYPE_FLOAT
@ AV_OPT_TYPE_FLOAT
Definition: opt.h:238
layout
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel layout
Definition: filter_design.txt:18
av_opt_next
const AVOption * av_opt_next(const void *obj, const AVOption *prev)
Iterate over all AVOptions belonging to obj.
Definition: opt.c:48
log.h
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:1923
AVOption::str
const char * str
Definition: opt.h:371
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
AVOptionRanges
List of AVOptionRange structs.
Definition: opt.h:425
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:370
pixfmt.h
av_opt_eval_int
int av_opt_eval_int(void *obj, const AVOption *o, const char *val, int *int_out)
dict.h
AVOption::type
enum AVOptionType type
Definition: opt.h:362
channel_layout.h
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:635
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:235
av_opt_get_chlayout
int av_opt_get_chlayout(void *obj, const char *name, int search_flags, AVChannelLayout *layout)
Definition: opt.c:1310
av_opt_child_next
void * av_opt_child_next(void *obj, void *prev)
Iterate over AVOptions-enabled children of obj.
Definition: opt.c:2003
AV_OPT_TYPE_PIXEL_FMT
@ AV_OPT_TYPE_PIXEL_FMT
Definition: opt.h:246
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:1645
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:2154
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:2136
av_opt_eval_float
int av_opt_eval_float(void *obj, const AVOption *o, const char *val, float *float_out)
AVOptionArrayDef::size_min
unsigned size_min
Minimum number of elements in the array.
Definition: opt.h:325
avutil.h
AVOption::unit
const char * unit
The logical unit to which the option belongs.
Definition: opt.h:396
av_opt_freep_ranges
void av_opt_freep_ranges(AVOptionRanges **ranges)
Free an AVOptionRanges struct and set it to NULL.
Definition: opt.c:2225
AVOptionRange::component_max
double component_max
Definition: opt.h:414
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Definition: opt.h:251
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
AV_OPT_TYPE_FLAGS
@ AV_OPT_TYPE_FLAGS
Definition: opt.h:234
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
av_opt_get
int av_opt_get(void *obj, const char *name, int search_flags, uint8_t **out_val)
Definition: opt.c:1147
h
h
Definition: vp9dsp_template.c:2038
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:1947
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:1248
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Definition: opt.h:239
av_opt_set_q
int av_opt_set_q(void *obj, const char *name, AVRational val, int search_flags)
Definition: opt.c:801
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:910
AVOption::max
double max
maximum valid value for the option
Definition: opt.h:384
AV_OPT_TYPE_CONST
@ AV_OPT_TYPE_CONST
Definition: opt.h:244
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:2377
AV_OPT_TYPE_UINT64
@ AV_OPT_TYPE_UINT64
Definition: opt.h:243
av_opt_get_q
int av_opt_get_q(void *obj, const char *name, int search_flags, AVRational *out_val)
Definition: opt.c:1232