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 110 of file avfilter.h.

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 116 of file avfilter.h.

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

Definition at line 121 of file avfilter.h.

The filter is a "metadata" filter - it does not modify the frame data in any way.

It may only affect the metadata (i.e. those fields copied by av_frame_copy_props()).

More precisely, this means:

• video: the data of any frame output by the filter must be exactly equal to some frame that is received on one of its inputs. Furthermore, all frames produced on a given output must correspond to frames received on the same input and their order must be unchanged. Note that the filter may still drop or duplicate the frames.
• audio: the data produced by the filter on any of its outputs (viewed e.g. as an array of interleaved samples) must be exactly equal to the data received by the filter on one of its inputs.

Definition at line 137 of file avfilter.h.

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 146 of file avfilter.h.

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 154 of file avfilter.h.

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

Definition at line 159 of file avfilter.h.

Process multiple parts of the frame concurrently.

Definition at line 397 of file avfilter.h.

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

Definition at line 739 of file avfilter.h.

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

Definition at line 740 of file avfilter.h.

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 844 of file avfilter.h.

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 858 of file avfilter.h.

Definition at line 992 of file avfilter.h.

Return the LIBAVFILTER_VERSION_INT constant.

Definition at line 77 of file avfilter.c.

Return the libavfilter build-time configuration.

Definition at line 83 of file avfilter.c.

Return the libavfilter license.

Definition at line 88 of file avfilter.c.

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 972 of file avfilter.c.

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

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 977 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().

Get the number of elements in an AVFilter's inputs or outputs array.

Definition at line 594 of file avfilter.c.

Referenced by show_filters().

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 161 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().

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

Definition at line 200 of file avfilter.c.

Referenced by free_link().

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 290 of file avfilter.c.

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

Make the filter instance process a command.

It is recommended to use avfilter_graph_send_command().

Definition at line 552 of file avfilter.c.

Referenced by avfilter_graph_send_command(), and ff_inlink_process_commands().

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 568 of file allfilters.c.

Referenced by avfilter_get_by_name(), avfilter_pad_count(), filter_child_class_iterate(), and show_filters().

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 579 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(), init_filter(), init_filter_graph(), init_filters(), insert_filter(), insert_trim(), lavfi_read_header(), main(), and query_formats().

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 938 of file avfilter.c.

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

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 895 of file avfilter.c.

Referenced by avfilter_init_str(), and init_filter_graph().

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 757 of file avfilter.c.

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

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 253 of file avfilter.c.

Referenced by query_formats().

Returns

AVClass for AVFilterContext.

See also

av_opt_find().

Definition at line 1562 of file avfilter.c.

Referenced by show_help_default().

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 84 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().

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 167 of file avfiltergraph.c.

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

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 285 of file avfiltergraph.c.

Create and add a filter instance into an existing graph.

The filter instance is created from the filter filt and inited with the parameter args. opaque is currently ignored.

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 140 of file avfiltergraph.c.

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

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 162 of file avfiltergraph.c.

Referenced by choose_pix_fmts(), configure_filtergraph(), and init().

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 1156 of file avfiltergraph.c.

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

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 121 of file avfiltergraph.c.

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

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 207 of file graphparser.c.

Referenced by init_filter(), and init_filters().

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 212 of file graphparser.c.

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

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 486 of file graphparser.c.

Referenced by main().

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 549 of file graphparser.c.

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

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 418 of file graphparser.c.

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

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 1174 of file avfiltergraph.c.

Referenced by check_keyboard_interaction(), and filter_frame().

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 1204 of file avfiltergraph.c.

Referenced by check_keyboard_interaction().

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 155 of file graphdump.c.

Referenced by lavfi_read_header().

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 1284 of file avfiltergraph.c.

Referenced by main(), and transcode_from_filter().