Graph-based frame editing library. More...

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_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16)
	Some filters support a generic "enable" expression option that can be used to enable or disable a filter in the timeline. More...

#define	AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)
	Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will have its filter_frame() callback(s) called as usual even when the enable expression is false. More...

#define	AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC \| AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)
	Handy mask to test whether the filter supports or no the timeline feature (internally or generically). More...

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

#define	AVFILTER_CMD_FLAG_ONE 1
	Stop once a filter understood the command (for target=all for example), fast filters are favored automatically. More...

#define	AVFILTER_CMD_FLAG_FAST 2
	Only execute command when its fast (like a video out that supports contrast adjustment in hw) More...

Typedefs
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...

Enumerations
enum	{ AVFILTER_AUTO_CONVERT_ALL = 0, AVFILTER_AUTO_CONVERT_NONE = -1 }

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...

void	avfilter_link_free (AVFilterLink **link)
	Free the link in *link, and set its pointer to NULL. More...

attribute_deprecated void	avfilter_link_set_closed (AVFilterLink *link, int closed)
	Set the closed field of a link. More...

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

int	avfilter_process_command (AVFilterContext filter, const char cmd, const char arg, char res, int res_len, int flags)
	Make the filter instance process a command. More...

const AVFilter *	av_filter_iterate (void **opaque)
	Iterate over all registered filters. More...

const AVFilter *	avfilter_get_by_name (const char *name)
	Get a filter definition matching the given name. 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, const char name)
	Get a filter instance identified by instance 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...

void	avfilter_graph_set_auto_convert (AVFilterGraph *graph, unsigned flags)
	Enable or disable automatic format conversion inside the 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_parse_ptr (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...

int	avfilter_graph_send_command (AVFilterGraph graph, const char target, const char cmd, const char arg, char *res, int res_len, int flags)
	Send a command to one or more filter instances. More...

int	avfilter_graph_queue_command (AVFilterGraph graph, const char target, const char cmd, const char arg, int flags, double ts)
	Queue a command for one or more filter instances. More...

char *	avfilter_graph_dump (AVFilterGraph graph, const char options)
	Dump a graph into a human-readable string representation. More...

int	avfilter_graph_request_oldest (AVFilterGraph *graph)
	Request a frame on the oldest sink link. More...

Detailed Description

Graph-based frame editing library.

Macro Definition Documentation

#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 105 of file avfilter.h.

Referenced by show_filters().

#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 111 of file avfilter.h.

Referenced by show_filters().

#define AVFILTER_FLAG_SLICE_THREADS (1 << 2)

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

Definition at line 116 of file avfilter.h.

Referenced by avfilter_init_dict(), and show_filters().

#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16)

Some filters support a generic "enable" expression option that can be used to enable or disable a filter in the timeline.

Filters supporting this option have this flag set. When the enable expression is false, the default no-op filter_frame() function is called in place of the filter_frame() callback defined on each input pad, thus the frame is passed unchanged to the next filters.

Definition at line 125 of file avfilter.h.

Referenced by ff_filter_activate(), and ff_filter_frame_framed().

#define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)

Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will have its filter_frame() callback(s) called as usual even when the enable expression is false.

The filter will disable filtering within the filter_frame() callback(s) itself, for example executing code depending on the AVFilterContext->is_disabled value.

Definition at line 133 of file avfilter.h.

#define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)

Handy mask to test whether the filter supports or no the timeline feature (internally or generically).

Definition at line 138 of file avfilter.h.

Referenced by set_enable_expr(), and show_filters().

#define AVFILTER_THREAD_SLICE (1 << 0)

Process multiple parts of the frame concurrently.

Definition at line 333 of file avfilter.h.

Referenced by avfilter_init_dict().

#define AVFILTER_CMD_FLAG_ONE 1

Stop once a filter understood the command (for target=all for example), fast filters are favored automatically.

Definition at line 691 of file avfilter.h.

Referenced by avfilter_graph_queue_command(), avfilter_graph_send_command(), check_keyboard_interaction(), and filter_frame().

#define AVFILTER_CMD_FLAG_FAST 2

Only execute command when its fast (like a video out that supports contrast adjustment in hw)

Definition at line 692 of file avfilter.h.

Referenced by avfilter_graph_send_command().

Typedef Documentation

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 823 of file avfilter.h.

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 837 of file avfilter.h.

Enumeration Type Documentation

anonymous enum

Enumerator
AVFILTER_AUTO_CONVERT_ALL	all automatic conversions enabled
AVFILTER_AUTO_CONVERT_NONE	all automatic conversions disabled

Definition at line 974 of file avfilter.h.

Function Documentation

unsigned avfilter_version ( void )

Return the LIBAVFILTER_VERSION_INT constant.

Definition at line 77 of file avfilter.c.

const char* avfilter_configuration ( void )

Return the libavfilter build-time configuration.

Definition at line 83 of file avfilter.c.

const char* avfilter_license ( void )

Return the libavfilter license.

Definition at line 88 of file avfilter.c.

int avfilter_pad_count ( const AVFilterPad * pads )

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

AVFilter.inputs/outputs).

Definition at line 578 of file avfilter.c.

Referenced by ff_filter_alloc().

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

Definition at line 1034 of file avfilter.c.

Referenced by describe_filter_link(), print_digraph(), and show_filters().

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

Definition at line 1039 of file avfilter.c.

Referenced by configure_input_filter(), configure_output_filter(), create_sink(), init_complex_filtergraph(), init_input_filter(), insert_trim(), lavfi_read_header(), main(), and show_filters().

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

Definition at line 135 of file avfilter.c.

Referenced by avfilter_graph_parse(), avfilter_insert_filter(), configure_input_audio_filter(), configure_input_video_filter(), configure_output_audio_filter(), configure_output_video_filter(), create_sink(), init_filter_graph(), insert_filter(), insert_trim(), lavfi_read_header(), and link_filter().

void avfilter_link_free ( AVFilterLink ** link )

Free the link in *link, and set its pointer to NULL.

Definition at line 174 of file avfilter.c.

Referenced by free_link().

attribute_deprecated void avfilter_link_set_closed	(	AVFilterLink *	link,
		int	closed
	)

Set the closed field of a link.

Deprecated:: applications are not supposed to mess with links, they should close the sinks.

Definition at line 235 of file avfilter.c.

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

Definition at line 277 of file avfilter.c.

Referenced by avfilter_config_links(), graph_config_links(), and process_command().

int avfilter_process_command	(	AVFilterContext *	filter,
		const char *	cmd,
		const char *	arg,
		char *	res,
		int	res_len,
		int	flags
	)

Make the filter instance process a command.

It is recommended to use avfilter_graph_send_command().

Definition at line 557 of file avfilter.c.

Referenced by avfilter_graph_send_command(), and ff_inlink_process_commands().

const AVFilter* av_filter_iterate ( void ** opaque )

Iterate over all registered filters.

Parameters

opaque a pointer where libavfilter will store the iteration state. Must point to NULL to start the iteration.

Returns: the next registered filter or NULL when the iteration is finished

Definition at line 455 of file allfilters.c.

Referenced by avfilter_get_by_name(), filter_child_class_next(), and show_filters().

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.

Definition at line 466 of file allfilters.c.

Referenced by configure_input_audio_filter(), configure_input_video_filter(), configure_output_audio_filter(), configure_output_video_filter(), create_filter(), create_sink(), graph_insert_fifos(), init_filter(), init_filter_graph(), init_filters(), insert_filter(), insert_trim(), lavfi_read_header(), main(), and query_formats().

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

Definition at line 924 of file avfilter.c.

Referenced by avfilter_graph_create_filter(), create_filter(), init_filter_graph(), insert_trim(), and main().

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.

Definition at line 887 of file avfilter.c.

Referenced by avfilter_init_str(), and init_filter_graph().

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

Definition at line 760 of file avfilter.c.

Referenced by avfilter_graph_alloc_filter(), avfilter_graph_create_filter(), avfilter_graph_free(), avfilter_graph_parse(), avfilter_graph_parse2(), avfilter_graph_parse_ptr(), create_filter(), and main().

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

Definition at line 240 of file avfilter.c.

Referenced by graph_insert_fifos(), and query_formats().

const AVClass* avfilter_get_class ( void )

Returns: AVClass for AVFilterContext.

See Also: av_opt_find().

Definition at line 1635 of file avfilter.c.

Referenced by show_help_default().

AVFilterGraph* avfilter_graph_alloc ( void )

Allocate a filter graph.

Returns: the allocated filter graph on success or NULL.

Examples:: filter_audio.c, filtering_audio.c, filtering_video.c, and transcoding.c.

Definition at line 83 of file avfiltergraph.c.

Referenced by configure_filtergraph(), init_complex_filtergraph(), init_filter(), init_filter_graph(), init_filters(), lavfi_read_header(), main(), and video_thread().

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 on failure.

Examples:: filter_audio.c.

Definition at line 170 of file avfiltergraph.c.

Referenced by avfilter_graph_create_filter(), create_filter(), init_filter_graph(), insert_trim(), and main().

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

Get a filter instance identified by instance name from graph.

Parameters

graph	filter graph to search through.
name	filter instance name (should be unique in the graph).

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

Definition at line 290 of file avfiltergraph.c.

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

Examples:: filtering_audio.c, filtering_video.c, and transcoding.c.

Definition at line 142 of file avfiltergraph.c.

Referenced by configure_input_audio_filter(), configure_input_video_filter(), configure_output_audio_filter(), configure_output_video_filter(), create_sink(), graph_insert_fifos(), init_filter(), init_filters(), insert_filter(), lavfi_read_header(), and query_formats().

void avfilter_graph_set_auto_convert	(	AVFilterGraph *	graph,
		unsigned	flags
	)

Enable or disable automatic format conversion inside the graph.

Note that format conversion can still happen inside explicitly inserted scale and aresample filters.

Parameters

flags any of the AVFILTER_AUTO_CONVERT_* constants

Definition at line 165 of file avfiltergraph.c.

Referenced by choose_pix_fmts(), and init().

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, filtering_audio.c, filtering_video.c, and transcoding.c.

Definition at line 1267 of file avfiltergraph.c.

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

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, filtering_audio.c, filtering_video.c, and transcoding.c.

Definition at line 120 of file avfiltergraph.c.

Referenced by audio_thread(), cleanup_filtergraph(), ffmpeg_cleanup(), init_complex_filtergraph(), lavfi_read_close(), main(), and video_thread().

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.

Examples:: filtering_audio.c, filtering_video.c, and transcoding.c.

Definition at line 198 of file graphparser.c.

Referenced by init_filter(), and init_filters().

void avfilter_inout_free ( AVFilterInOut ** inout )

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

If *inout is NULL, do nothing.

Examples:: filtering_audio.c, filtering_video.c, and transcoding.c.

Definition at line 203 of file graphparser.c.

Referenced by avfilter_graph_parse(), avfilter_graph_parse2(), avfilter_graph_parse_ptr(), configure_filtergraph(), init_complex_filtergraph(), init_filter(), init_filters(), init_output_filter(), and lavfi_read_header().

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.

Note: The caller must provide the lists of inputs and outputs, which therefore must be known before calling the function.; 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.

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

Definition at line 475 of file graphparser.c.

Referenced by main().

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

Add a graph described by a string to a graph.

In the graph filters description, if the input label of the first filter is not specified, "in" is assumed; if the output label of the last filter is not specified, "out" is assumed.

Parameters

graph	the filter graph where to link the parsed graph context
filters	string to be parsed
inputs	pointer to a linked list to the inputs of the graph, may be NULL. If non-NULL, *inputs is updated to contain the list of open inputs after the parsing, should be freed with avfilter_inout_free().
outputs	pointer to a linked list to the outputs of the graph, may be NULL. If non-NULL, *outputs is updated to contain the list of open outputs after the parsing, should be freed with avfilter_inout_free().

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

Examples:: filtering_audio.c, filtering_video.c, and transcoding.c.

Definition at line 538 of file graphparser.c.

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

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: This function returns the inputs and outputs that are left unlinked after parsing the graph and the caller then deals with them.; This function 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.

Definition at line 407 of file graphparser.c.

Referenced by avfilter_graph_parse(), configure_filtergraph(), and init_complex_filtergraph().

int avfilter_graph_send_command	(	AVFilterGraph *	graph,
		const char *	target,
		const char *	cmd,
		const char *	arg,
		char *	res,
		int	res_len,
		int	flags
	)

Send a command to one or more filter instances.

Parameters

graph	the filter graph
target	the filter(s) to which the command should be sent "all" sends to all filters otherwise it can be a filter or filter instance name which will send the command to all matching filters.
cmd	the command to send, for handling simplicity all commands must be alphanumeric only
arg	the argument for the command
res	a buffer with size res_size where the filter(s) can return a response.

Returns: >=0 on success otherwise an error code. AVERROR(ENOSYS) on unsupported commands

Definition at line 1287 of file avfiltergraph.c.

Referenced by check_keyboard_interaction(), and filter_frame().

int avfilter_graph_queue_command	(	AVFilterGraph *	graph,
		const char *	target,
		const char *	cmd,
		const char *	arg,
		int	flags,
		double	ts
	)

Queue a command for one or more filter instances.

Parameters

graph	the filter graph
target	the filter(s) to which the command should be sent "all" sends to all filters otherwise it can be a filter or filter instance name which will send the command to all matching filters.
cmd	the command to sent, for handling simplicity all commands must be alphanumeric only
arg	the argument for the command
ts	time at which the command should be sent to the filter

Note: As this executes commands after this function returns, no return code from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.

Definition at line 1317 of file avfiltergraph.c.

Referenced by check_keyboard_interaction().

char* avfilter_graph_dump	(	AVFilterGraph *	graph,
		const char *	options
	)

Dump a graph into a human-readable string representation.

Parameters

graph	the graph to dump
options	formatting options; currently ignored

Returns: a string, or NULL in case of memory allocation failure; the string must be freed using av_free

Definition at line 154 of file graphdump.c.

Referenced by lavfi_read_header().

int avfilter_graph_request_oldest ( AVFilterGraph * graph )

Request a frame on the oldest sink link.

If the request returns AVERROR_EOF, try the next.

Note that this function is not meant to be the sole scheduling mechanism of a filtergraph, only a convenience function to help drain a filtergraph in a balanced way under normal circumstances.

Also note that AVERROR_EOF does not mean that frames did not arrive on some of the sinks during the process. When there are multiple sink links, in case the requested link returns an EOF, this may cause a filter to flush pending frames which are sent to another sink link, although unrequested.

Returns: the return value of ff_request_frame(), or AVERROR_EOF if all links returned AVERROR_EOF

Definition at line 1397 of file avfiltergraph.c.

Referenced by main(), and transcode_from_filter().

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