Modules
	Buffer sink API

	Buffer source API

Files
file	avfilter.h
	Main libavfilter public API header.

file	version.h
	Libavfilter version macros.

Data Structures
struct	AVFilter
	Filter definition. More...

struct	AVFilterContext
	An instance of a filter. More...

struct	AVFilterLink
	A link between two filters. More...

struct	AVFilterGraph

struct	AVFilterInOut
	A linked-list of the inputs/outputs of the filter chain. More...

Macros
#define	AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
	The number of the filter inputs is not determined just by AVFilter.inputs. More...

#define	AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
	The number of the filter outputs is not determined just by AVFilter.outputs. More...

#define	AVFILTER_FLAG_SLICE_THREADS (1 << 2)
	The filter supports multithreading by splitting frames into multiple parts and processing them concurrently. More...

#define	AVFILTER_THREAD_SLICE (1 << 0)
	Process multiple parts of the frame concurrently. More...

Typedefs
typedef struct AVFilterPad	AVFilterPad

typedef struct AVFilterFormats	AVFilterFormats

typedef struct AVFilterInternal	AVFilterInternal

typedef struct AVFilterGraphInternal	AVFilterGraphInternal

typedef int()	avfilter_action_func(AVFilterContext ctx, void arg, int jobnr, int nb_jobs)
	A function pointer passed to the AVFilterGraph::execute callback to be executed multiple times, possibly in parallel. More...

typedef int()	avfilter_execute_func(AVFilterContext ctx, avfilter_action_func func, void arg, int ret, int nb_jobs)
	A function executing multiple jobs, possibly in parallel. More...

Functions
unsigned	avfilter_version (void)
	Return the LIBAVFILTER_VERSION_INT constant. More...

const char *	avfilter_configuration (void)
	Return the libavfilter build-time configuration. More...

const char *	avfilter_license (void)
	Return the libavfilter license. More...

int	avfilter_pad_count (const AVFilterPad *pads)
	Get the number of elements in a NULL-terminated array of AVFilterPads (e.g. More...

const char *	avfilter_pad_get_name (const AVFilterPad *pads, int pad_idx)
	Get the name of an AVFilterPad. More...

enum AVMediaType	avfilter_pad_get_type (const AVFilterPad *pads, int pad_idx)
	Get the type of an AVFilterPad. More...

int	avfilter_link (AVFilterContext src, unsigned srcpad, AVFilterContext dst, unsigned dstpad)
	Link two filters together. More...

int	avfilter_config_links (AVFilterContext *filter)
	Negotiate the media format, dimensions, etc of all inputs to a filter. More...

void	avfilter_register_all (void)
	Initialize the filter system. More...

int	avfilter_register (AVFilter *filter)
	Register a filter. More...

const AVFilter *	avfilter_get_by_name (const char *name)
	Get a filter definition matching the given name. More...

const AVFilter *	avfilter_next (const AVFilter *prev)
	Iterate over all registered filters. More...

int	avfilter_init_str (AVFilterContext ctx, const char args)
	Initialize a filter with the supplied parameters. More...

int	avfilter_init_dict (AVFilterContext ctx, AVDictionary *options)
	Initialize a filter with the supplied dictionary of options. More...

void	avfilter_free (AVFilterContext *filter)
	Free a filter context. More...

int	avfilter_insert_filter (AVFilterLink link, AVFilterContext filt, unsigned filt_srcpad_idx, unsigned filt_dstpad_idx)
	Insert a filter in the middle of an existing link. More...

const AVClass *	avfilter_get_class (void)

AVFilterGraph *	avfilter_graph_alloc (void)
	Allocate a filter graph. More...

AVFilterContext *	avfilter_graph_alloc_filter (AVFilterGraph graph, const AVFilter filter, const char *name)
	Create a new filter instance in a filter graph. More...

AVFilterContext *	avfilter_graph_get_filter (AVFilterGraph graph, char name)
	Get a filter instance with name name from graph. More...

int	avfilter_graph_create_filter (AVFilterContext *filt_ctx, const AVFilter filt, const char name, const char args, void opaque, AVFilterGraph graph_ctx)
	Create and add a filter instance into an existing graph. More...

int	avfilter_graph_config (AVFilterGraph graphctx, void log_ctx)
	Check validity and configure all the links and formats in the graph. More...

void	avfilter_graph_free (AVFilterGraph **graph)
	Free a graph, destroy its links, and set *graph to NULL. More...

AVFilterInOut *	avfilter_inout_alloc (void)
	Allocate a single AVFilterInOut entry. More...

void	avfilter_inout_free (AVFilterInOut **inout)
	Free the supplied list of AVFilterInOut and set *inout to NULL. More...

int	avfilter_graph_parse (AVFilterGraph graph, const char filters, AVFilterInOut inputs, AVFilterInOut outputs, void *log_ctx)
	Add a graph described by a string to a graph. More...

int	avfilter_graph_parse2 (AVFilterGraph graph, const char filters, AVFilterInOut inputs, AVFilterInOut outputs)
	Add a graph described by a string to a graph. More...

Detailed Description

Macro Definition Documentation

◆ AVFILTER_FLAG_DYNAMIC_INPUTS

#define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)

The number of the filter inputs is not determined just by AVFilter.inputs.

The filter might add additional inputs during initialization depending on the options supplied to it.

Definition at line 103 of file avfilter.h.

◆ AVFILTER_FLAG_DYNAMIC_OUTPUTS

#define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)

The number of the filter outputs is not determined just by AVFilter.outputs.

The filter might add additional outputs during initialization depending on the options supplied to it.

Definition at line 109 of file avfilter.h.

◆ AVFILTER_FLAG_SLICE_THREADS

#define AVFILTER_FLAG_SLICE_THREADS (1 << 2)

The filter supports multithreading by splitting frames into multiple parts and processing them concurrently.

Definition at line 114 of file avfilter.h.

◆ AVFILTER_THREAD_SLICE

#define AVFILTER_THREAD_SLICE (1 << 0)

Process multiple parts of the frame concurrently.

Definition at line 259 of file avfilter.h.

Typedef Documentation

◆ AVFilterPad

typedef struct AVFilterPad AVFilterPad

Definition at line 67 of file avfilter.h.

◆ AVFilterFormats

typedef struct AVFilterFormats AVFilterFormats

Definition at line 68 of file avfilter.h.

◆ AVFilterInternal

typedef struct AVFilterInternal AVFilterInternal

Definition at line 261 of file avfilter.h.

◆ AVFilterGraphInternal

typedef struct AVFilterGraphInternal AVFilterGraphInternal

Definition at line 538 of file avfilter.h.

◆ avfilter_action_func

typedef int() avfilter_action_func(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)

A function pointer passed to the AVFilterGraph::execute callback to be executed multiple times, possibly in parallel.

Parameters

ctx	the filter context the job belongs to
arg	an opaque parameter passed through from AVFilterGraph::execute
jobnr	the index of the job being executed
nb_jobs	the total number of jobs

Returns: 0 on success, a negative AVERROR on error

Definition at line 552 of file avfilter.h.

◆ avfilter_execute_func

typedef int() avfilter_execute_func(AVFilterContext *ctx, avfilter_action_func *func, void *arg, int *ret, int nb_jobs)

A function executing multiple jobs, possibly in parallel.

Parameters

ctx	the filter context to which the jobs belong
func	the function to be called multiple times
arg	the argument to be passed to func
ret	a nb_jobs-sized array to be filled with return values from each invocation of func
nb_jobs	the number of jobs to execute

Returns: 0 on success, a negative AVERROR on error

Definition at line 566 of file avfilter.h.

Function Documentation

◆ avfilter_version()

unsigned avfilter_version ( void )

Return the LIBAVFILTER_VERSION_INT constant.

◆ avfilter_configuration()

const char* avfilter_configuration ( void )

Return the libavfilter build-time configuration.

◆ avfilter_license()

const char* avfilter_license ( void )

Return the libavfilter license.

◆ avfilter_pad_count()

int avfilter_pad_count ( const AVFilterPad * pads )

Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.

AVFilter.inputs/outputs).

◆ avfilter_pad_get_name()

const char* avfilter_pad_get_name	(	const AVFilterPad *	pads,
		int	pad_idx
	)

Get the name of an AVFilterPad.

Parameters

pads	an array of AVFilterPads
pad_idx	index of the pad in the array it; is the caller's responsibility to ensure the index is valid

Returns: name of the pad_idx'th pad in pads

◆ avfilter_pad_get_type()

enum AVMediaType avfilter_pad_get_type	(	const AVFilterPad *	pads,
		int	pad_idx
	)

Get the type of an AVFilterPad.

Parameters

pads	an array of AVFilterPads
pad_idx	index of the pad in the array; it is the caller's responsibility to ensure the index is valid

Returns: type of the pad_idx'th pad in pads

◆ avfilter_link()

int avfilter_link	(	AVFilterContext *	src,
		unsigned	srcpad,
		AVFilterContext *	dst,
		unsigned	dstpad
	)

Link two filters together.

Parameters

src	the source filter
srcpad	index of the output pad on the source filter
dst	the destination filter
dstpad	index of the input pad on the destination filter

Returns: zero on success

Examples:: filter_audio.c.

Referenced by init_filter_graph().

◆ avfilter_config_links()

int avfilter_config_links ( AVFilterContext * filter )

Negotiate the media format, dimensions, etc of all inputs to a filter.

Parameters

filter the filter to negotiate the properties for its inputs

Returns: zero on successful negotiation

◆ avfilter_register_all()

void avfilter_register_all ( void )

Initialize the filter system.

Register all builtin filters.

Examples:: filter_audio.c.

Referenced by main().

◆ avfilter_register()

int avfilter_register ( AVFilter * filter )

Register a filter.

This is only needed if you plan to use avfilter_get_by_name later to lookup the AVFilter structure by name. A filter can still by instantiated with avfilter_graph_alloc_filter even if it is not registered.

Parameters

filter the filter to register

Returns: 0 if the registration was successful, a negative value otherwise

◆ avfilter_get_by_name()

const AVFilter* avfilter_get_by_name ( const char * name )

Get a filter definition matching the given name.

Parameters

name	the filter name to find

Returns: the filter definition, if any matching one is registered. NULL if none found.

Examples:: filter_audio.c.

Referenced by init_filter_graph().

◆ avfilter_next()

const AVFilter* avfilter_next ( const AVFilter * prev )

Iterate over all registered filters.

Returns: If prev is non-NULL, next registered filter after prev or NULL if prev is the last filter. If prev is NULL, return the first registered filter.

◆ avfilter_init_str()

int avfilter_init_str	(	AVFilterContext *	ctx,
		const char *	args
	)

Initialize a filter with the supplied parameters.

Parameters

ctx	uninitialized filter context to initialize
args	Options to initialize the filter with. This must be a ':'-separated list of options in the 'key=value' form. May be NULL if the options have been set directly using the AVOptions API or there are no options that need to be set.

Returns: 0 on success, a negative AVERROR on failure

Examples:: filter_audio.c.

Referenced by init_filter_graph().

◆ avfilter_init_dict()

int avfilter_init_dict	(	AVFilterContext *	ctx,
		AVDictionary **	options
	)

Initialize a filter with the supplied dictionary of options.

Parameters

ctx	uninitialized filter context to initialize
options	An AVDictionary filled with options for this filter. On return this parameter will be destroyed and replaced with a dict containing options that were not found. This dictionary must be freed by the caller. May be NULL, then this function is equivalent to avfilter_init_str() with the second parameter set to NULL.

Returns: 0 on success, a negative AVERROR on failure

Note: This function and avfilter_init_str() do essentially the same thing, the difference is in manner in which the options are passed. It is up to the calling code to choose whichever is more preferable. The two functions also behave differently when some of the provided options are not declared as supported by the filter. In such a case, avfilter_init_str() will fail, but this function will leave those extra options in the options AVDictionary and continue as usual.

Examples:: filter_audio.c.

Referenced by init_filter_graph().

◆ avfilter_free()

void avfilter_free ( AVFilterContext * filter )

Free a filter context.

This will also remove the filter from its filtergraph's list of filters.

Parameters

filter the filter to free

◆ avfilter_insert_filter()

int avfilter_insert_filter	(	AVFilterLink *	link,
		AVFilterContext *	filt,
		unsigned	filt_srcpad_idx,
		unsigned	filt_dstpad_idx
	)

Insert a filter in the middle of an existing link.

Parameters

link	the link into which the filter should be inserted
filt	the filter to be inserted
filt_srcpad_idx	the input pad on the filter to connect
filt_dstpad_idx	the output pad on the filter to connect

Returns: zero on success

◆ avfilter_get_class()

const AVClass* avfilter_get_class ( void )

Returns: AVClass for AVFilterContext.

See also: av_opt_find().

◆ avfilter_graph_alloc()

AVFilterGraph* avfilter_graph_alloc ( void )

Allocate a filter graph.

Returns: the allocated filter graph on success or NULL.

Examples:: filter_audio.c.

Referenced by init_filter_graph().

◆ avfilter_graph_alloc_filter()

AVFilterContext* avfilter_graph_alloc_filter	(	AVFilterGraph *	graph,
		const AVFilter *	filter,
		const char *	name
	)

Create a new filter instance in a filter graph.

Parameters

graph	graph in which the new filter will be used
filter	the filter to create an instance of
name	Name to give to the new instance (will be copied to AVFilterContext.name). This may be used by the caller to identify different filters, libavfilter itself assigns no semantics to this parameter. May be NULL.

Returns: the context of the newly created filter instance (note that it is also retrievable directly through AVFilterGraph.filters or with avfilter_graph_get_filter()) on success or NULL or failure.

Examples:: filter_audio.c.

Referenced by init_filter_graph().

◆ avfilter_graph_get_filter()

AVFilterContext* avfilter_graph_get_filter	(	AVFilterGraph *	graph,
		char *	name
	)

Get a filter instance with name name from graph.

Returns: the pointer to the found filter instance or NULL if it cannot be found.

◆ avfilter_graph_create_filter()

int avfilter_graph_create_filter	(	AVFilterContext **	filt_ctx,
		const AVFilter *	filt,
		const char *	name,
		const char *	args,
		void *	opaque,
		AVFilterGraph *	graph_ctx
	)

Create and add a filter instance into an existing graph.

The filter instance is created from the filter filt and inited with the parameters args and opaque.

In case of success put in *filt_ctx the pointer to the created filter instance, otherwise set *filt_ctx to NULL.

Parameters

name	the instance name to give to the created filter instance
graph_ctx	the filter graph

Returns: a negative AVERROR error code in case of failure, a non negative value otherwise

◆ avfilter_graph_config()

int avfilter_graph_config	(	AVFilterGraph *	graphctx,
		void *	log_ctx
	)

Check validity and configure all the links and formats in the graph.

Parameters

graphctx	the filter graph
log_ctx	context used for logging

Returns: 0 in case of success, a negative AVERROR code otherwise

Examples:: filter_audio.c.

Referenced by init_filter_graph().

◆ avfilter_graph_free()

void avfilter_graph_free ( AVFilterGraph ** graph )

Free a graph, destroy its links, and set *graph to NULL.

If *graph is NULL, do nothing.

Examples:: filter_audio.c.

Referenced by main().

◆ avfilter_inout_alloc()

AVFilterInOut* avfilter_inout_alloc ( void )

Allocate a single AVFilterInOut entry.

Must be freed with avfilter_inout_free().

Returns: allocated AVFilterInOut on success, NULL on failure.

◆ avfilter_inout_free()

void avfilter_inout_free ( AVFilterInOut ** inout )

Free the supplied list of AVFilterInOut and set *inout to NULL.

If *inout is NULL, do nothing.

◆ avfilter_graph_parse()

int avfilter_graph_parse	(	AVFilterGraph *	graph,
		const char *	filters,
		AVFilterInOut *	inputs,
		AVFilterInOut *	outputs,
		void *	log_ctx
	)

Add a graph described by a string to a graph.

Parameters

graph	the filter graph where to link the parsed graph context
filters	string to be parsed
inputs	linked list to the inputs of the graph
outputs	linked list to the outputs of the graph

Returns: zero on success, a negative AVERROR code on error

◆ avfilter_graph_parse2()

int avfilter_graph_parse2	(	AVFilterGraph *	graph,
		const char *	filters,
		AVFilterInOut **	inputs,
		AVFilterInOut **	outputs
	)

Add a graph described by a string to a graph.

Parameters

[in]	graph	the filter graph where to link the parsed graph context
[in]	filters	string to be parsed
[out]	inputs	a linked list of all free (unlinked) inputs of the parsed graph will be returned here. It is to be freed by the caller using avfilter_inout_free().
[out]	outputs	a linked list of all free (unlinked) outputs of the parsed graph will be returned here. It is to be freed by the caller using avfilter_inout_free().

Returns: zero on success, a negative AVERROR code on error

Note: the difference between avfilter_graph_parse2() and avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides the lists of inputs and outputs, which therefore must be known before calling the function. On the other hand, avfilter_graph_parse2() returns the inputs and outputs that are left unlinked after parsing the graph and the caller then deals with them. Another difference is that in avfilter_graph_parse(), the inputs parameter describes inputs of the already existing part of the graph; i.e. from the point of view of the newly created part, they are outputs. Similarly the outputs parameter describes outputs of the already existing filters, which are provided as inputs to the parsed filters. avfilter_graph_parse2() takes the opposite approach – it makes no reference whatsoever to already existing parts of the graph and the inputs parameter will on return contain inputs of the newly parsed part of the graph. Analogously the outputs parameter will contain outputs of the newly created filters.

Modules

Files

Data Structures

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

◆ AVFILTER_FLAG_DYNAMIC_INPUTS

◆ AVFILTER_FLAG_DYNAMIC_OUTPUTS

◆ AVFILTER_FLAG_SLICE_THREADS

◆ AVFILTER_THREAD_SLICE

Typedef Documentation

◆ AVFilterPad

◆ AVFilterFormats

◆ AVFilterInternal

◆ AVFilterGraphInternal

◆ avfilter_action_func

◆ avfilter_execute_func

Function Documentation

◆ avfilter_version()

◆ avfilter_configuration()

◆ avfilter_license()

◆ avfilter_pad_count()

◆ avfilter_pad_get_name()

◆ avfilter_pad_get_type()

◆ avfilter_link()

◆ avfilter_config_links()

◆ avfilter_register_all()

◆ avfilter_register()

◆ avfilter_get_by_name()

◆ avfilter_next()

◆ avfilter_init_str()

◆ avfilter_init_dict()

◆ avfilter_free()

◆ avfilter_insert_filter()

◆ avfilter_get_class()

◆ avfilter_graph_alloc()

◆ avfilter_graph_alloc_filter()

◆ avfilter_graph_get_filter()

◆ avfilter_graph_create_filter()

◆ avfilter_graph_config()

◆ avfilter_graph_free()

◆ avfilter_inout_alloc()

◆ avfilter_inout_free()

◆ avfilter_graph_parse()

◆ avfilter_graph_parse2()