Option setting functions

Those functions set the field of obj with the given name to value. More...

Macros
#define	av_opt_set_int_list(obj, name, val, term, flags)
	Set a binary option to an integer list.

Functions
int	av_opt_set (void *obj, const char *name, const char *val, int search_flags)
int	av_opt_set_int (void *obj, const char *name, int64_t val, int search_flags)
int	av_opt_set_double (void *obj, const char *name, double val, int search_flags)
int	av_opt_set_q (void *obj, const char *name, AVRational val, int search_flags)
int	av_opt_set_bin (void *obj, const char *name, const uint8_t *val, int size, int search_flags)
int	av_opt_set_image_size (void *obj, const char *name, int w, int h, int search_flags)
int	av_opt_set_pixel_fmt (void *obj, const char *name, enum AVPixelFormat fmt, int search_flags)
int	av_opt_set_sample_fmt (void *obj, const char *name, enum AVSampleFormat fmt, int search_flags)
int	av_opt_set_video_rate (void *obj, const char *name, AVRational val, int search_flags)
int	av_opt_set_chlayout (void *obj, const char *name, const AVChannelLayout *layout, int search_flags)
int	av_opt_set_dict_val (void *obj, const char *name, const AVDictionary *val, int search_flags)
int	av_opt_set_array (void *obj, const char *name, int search_flags, unsigned int start_elem, unsigned int nb_elems, enum AVOptionType val_type, const void *val)
	Add, replace, or remove elements for an array option.

Detailed Description

Those functions set the field of obj with the given name to value.

Parameters

[in]	obj	A struct whose first element is a pointer to an AVClass.
[in]	name	the name of the field to set
[in]	val	The value to set. In case of av_opt_set() if the field is not of a string type, then the given string is parsed. SI postfixes and some named scalars are supported. If the field is of a numeric type, it has to be a numeric or named scalar. Behavior with more than one scalar and +- infix operators is undefined. If the field is of a flags type, it has to be a sequence of numeric scalars or named flags separated by '+' or '-'. Prefixing a flag with '+' causes it to be set without affecting the other flags; similarly, '-' unsets a flag. If the field is of a dictionary type, it has to be a ':' separated list of key=value parameters. Values containing ':' special characters must be escaped.
	search_flags	flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN is passed here, then the option may be set on a child of obj.

Returns

0 if the value has been set, or an AVERROR code in case of error: AVERROR_OPTION_NOT_FOUND if no matching option exists AVERROR(ERANGE) if the value is out of range AVERROR(EINVAL) if the value is not valid

Macro Definition Documentation

av_opt_set_int_list

#define av_opt_set_int_list	(		obj,
			name,
			val,
			term,
			flags
	)

Value:

    (av_int_list_length(val, term) > INT_MAX / sizeof(*(val)) ? \
     AVERROR(EINVAL) : \
     av_opt_set_bin(obj, name, (const uint8_t *)(val), \
                    av_int_list_length(val, term) * sizeof(*(val)), flags))

Set a binary option to an integer list.

Parameters

obj	AVClass object to set options on
name	name of the binary option
val	pointer to an integer list (must have the correct type with regard to the contents of the list)
term	list terminator (usually 0 or -1)
flags	search flags

Examples

decode_filter_audio.c, and decode_filter_video.c.

Definition at line 899 of file opt.h.

Function Documentation

av_opt_set()

int av_opt_set	(	void *	obj,
		const char *	name,
		const char *	val,
		int	search_flags
	)

Examples

decode_filter_audio.c, encode_video.c, filter_audio.c, and transcode.c.

Referenced by init_filter(), init_filter_graph(), init_filters(), and main().

av_opt_set_int()

int av_opt_set_int	(	void *	obj,
		const char *	name,
		int64_t	val,
		int	search_flags
	)

Examples

filter_audio.c, mux.c, and resample_audio.c.

Referenced by init_filter_graph(), main(), and open_audio().

av_opt_set_double()

int av_opt_set_double	(	void *	obj,
		const char *	name,
		double	val,
		int	search_flags
	)

av_opt_set_q()

int av_opt_set_q	(	void *	obj,
		const char *	name,
		AVRational	val,
		int	search_flags
	)

Examples

filter_audio.c.

Referenced by init_filter_graph().

av_opt_set_bin()

int av_opt_set_bin	(	void *	obj,
		const char *	name,
		const uint8_t *	val,
		int	size,
		int	search_flags
	)

Examples

transcode.c.

Referenced by init_filter().

av_opt_set_image_size()

int av_opt_set_image_size	(	void *	obj,
		const char *	name,
		int	w,
		int	h,
		int	search_flags
	)

av_opt_set_pixel_fmt()

int av_opt_set_pixel_fmt	(	void *	obj,
		const char *	name,
		enum AVPixelFormat	fmt,
		int	search_flags
	)

av_opt_set_sample_fmt()

int av_opt_set_sample_fmt	(	void *	obj,
		const char *	name,
		enum AVSampleFormat	fmt,
		int	search_flags
	)

Examples

mux.c, and resample_audio.c.

Referenced by main(), and open_audio().

av_opt_set_video_rate()

int av_opt_set_video_rate	(	void *	obj,
		const char *	name,
		AVRational	val,
		int	search_flags
	)

av_opt_set_chlayout()

int av_opt_set_chlayout	(	void *	obj,
		const char *	name,
		const AVChannelLayout *	layout,
		int	search_flags
	)

Note

Any old chlayout present is discarded and replaced with a copy of the new one. The caller still owns layout and is responsible for uninitializing it.

Examples

mux.c, and resample_audio.c.

Referenced by main(), and open_audio().

av_opt_set_dict_val()

int av_opt_set_dict_val	(	void *	obj,
		const char *	name,
		const AVDictionary *	val,
		int	search_flags
	)

Note

Any old dictionary present is discarded and replaced with a copy of the new one. The caller still owns val is and responsible for freeing it.

av_opt_set_array()

int av_opt_set_array	(	void *	obj,
		const char *	name,
		int	search_flags,
		unsigned int	start_elem,
		unsigned int	nb_elems,
		enum AVOptionType	val_type,
		const void *	val
	)

Add, replace, or remove elements for an array option.

Which of these operations is performed depends on the values of val and search_flags.

Parameters

start_elem	Index of the first array element to modify; must not be larger than array size as returned by av_opt_get_array_size().
nb_elems	number of array elements to modify; when val is NULL, start_elem+nb_elems must not be larger than array size as returned by av_opt_get_array_size()
val_type	Option type corresponding to the type of val, ignored when val is NULL.

The effect of this function will will be as if av_opt_setX() was called for each element, where X is specified by type. E.g. AV_OPT_TYPE_STRING corresponds to av_opt_set().

Typically this should be the same as the scalarized type of the AVOption being set, but certain conversions are also possible - the same as those done by the corresponding av_opt_set*() function. E.g. any option type can be set from a string, numeric types can be set from int64, double, or rational, etc.

Parameters

val

Array with nb_elems elements or NULL. When NULL, nb_elems array elements starting at start_elem are removed from the array. Any array elements remaining at the end are shifted by nb_elems towards the first element in order to keep the array contiguous. Otherwise (val is non-NULL), the type of val must match the underlying C type as documented for val_type. When AV_OPT_ARRAY_REPLACE is not set in search_flags, the array is enlarged by nb_elems, and the contents of val are inserted at start_elem. Previously existing array elements from start_elem onwards (if present) are shifted by nb_elems away from the first element in order to make space for the new elements. When AV_OPT_ARRAY_REPLACE is set in search_flags, the contents of val replace existing array elements from start_elem to start_elem+nb_elems (if present). New array size is max(start_elem + nb_elems, old array size).