3 * Copyright (c) 2007 Bobby Bingham
5 * This file is part of FFmpeg.
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.
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.
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
22 #ifndef AVFILTER_AVFILTER_H
23 #define AVFILTER_AVFILTER_H
28 * Main libavfilter public API header
32 * @defgroup lavfi Libavfilter - graph-based frame editing library
38 #include "libavutil/attributes.h"
39 #include "libavutil/avutil.h"
40 #include "libavutil/dict.h"
41 #include "libavutil/frame.h"
42 #include "libavutil/log.h"
43 #include "libavutil/samplefmt.h"
44 #include "libavutil/pixfmt.h"
45 #include "libavutil/rational.h"
47 #include "libavfilter/version.h"
50 * Return the LIBAVFILTER_VERSION_INT constant.
52 unsigned avfilter_version(void);
55 * Return the libavfilter build-time configuration.
57 const char *avfilter_configuration(void);
60 * Return the libavfilter license.
62 const char *avfilter_license(void);
64 typedef struct AVFilterContext AVFilterContext;
65 typedef struct AVFilterLink AVFilterLink;
66 typedef struct AVFilterPad AVFilterPad;
67 typedef struct AVFilterFormats AVFilterFormats;
70 * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
71 * AVFilter.inputs/outputs).
73 int avfilter_pad_count(const AVFilterPad *pads);
76 * Get the name of an AVFilterPad.
78 * @param pads an array of AVFilterPads
79 * @param pad_idx index of the pad in the array it; is the caller's
80 * responsibility to ensure the index is valid
82 * @return name of the pad_idx'th pad in pads
84 const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
87 * Get the type of an AVFilterPad.
89 * @param pads an array of AVFilterPads
90 * @param pad_idx index of the pad in the array; it is the caller's
91 * responsibility to ensure the index is valid
93 * @return type of the pad_idx'th pad in pads
95 enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
98 * The number of the filter inputs is not determined just by AVFilter.inputs.
99 * The filter might add additional inputs during initialization depending on the
100 * options supplied to it.
102 #define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
104 * The number of the filter outputs is not determined just by AVFilter.outputs.
105 * The filter might add additional outputs during initialization depending on
106 * the options supplied to it.
108 #define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
110 * The filter supports multithreading by splitting frames into multiple parts
111 * and processing them concurrently.
113 #define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
115 * Some filters support a generic "enable" expression option that can be used
116 * to enable or disable a filter in the timeline. Filters supporting this
117 * option have this flag set. When the enable expression is false, the default
118 * no-op filter_frame() function is called in place of the filter_frame()
119 * callback defined on each input pad, thus the frame is passed unchanged to
122 #define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16)
124 * Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will
125 * have its filter_frame() callback(s) called as usual even when the enable
126 * expression is false. The filter will disable filtering within the
127 * filter_frame() callback(s) itself, for example executing code depending on
128 * the AVFilterContext->is_disabled value.
130 #define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)
132 * Handy mask to test whether the filter supports or no the timeline feature
133 * (internally or generically).
135 #define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)
138 * Filter definition. This defines the pads a filter contains, and all the
139 * callback functions used to interact with the filter.
141 typedef struct AVFilter {
143 * Filter name. Must be non-NULL and unique among filters.
148 * A description of the filter. May be NULL.
150 * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
152 const char *description;
155 * List of inputs, terminated by a zeroed element.
157 * NULL if there are no (static) inputs. Instances of filters with
158 * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in
161 const AVFilterPad *inputs;
163 * List of outputs, terminated by a zeroed element.
165 * NULL if there are no (static) outputs. Instances of filters with
166 * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in
169 const AVFilterPad *outputs;
172 * A class for the private data, used to declare filter private AVOptions.
173 * This field is NULL for filters that do not declare any options.
175 * If this field is non-NULL, the first member of the filter private data
176 * must be a pointer to AVClass, which will be set by libavfilter generic
177 * code to this class.
179 const AVClass *priv_class;
182 * A combination of AVFILTER_FLAG_*
186 /*****************************************************************
187 * All fields below this line are not part of the public API. They
188 * may not be used outside of libavfilter and can be changed and
190 * New public fields should be added right above.
191 *****************************************************************
195 * Filter initialization function.
197 * This callback will be called only once during the filter lifetime, after
198 * all the options have been set, but before links between filters are
199 * established and format negotiation is done.
201 * Basic filter initialization should be done here. Filters with dynamic
202 * inputs and/or outputs should create those inputs/outputs here based on
203 * provided options. No more changes to this filter's inputs/outputs can be
204 * done after this callback.
206 * This callback must not assume that the filter links exist or frame
207 * parameters are known.
209 * @ref AVFilter.uninit "uninit" is guaranteed to be called even if
210 * initialization fails, so this callback does not have to clean up on
213 * @return 0 on success, a negative AVERROR on failure
215 int (*init)(AVFilterContext *ctx);
218 * Should be set instead of @ref AVFilter.init "init" by the filters that
219 * want to pass a dictionary of AVOptions to nested contexts that are
220 * allocated during init.
222 * On return, the options dict should be freed and replaced with one that
223 * contains all the options which could not be processed by this filter (or
224 * with NULL if all the options were processed).
226 * Otherwise the semantics is the same as for @ref AVFilter.init "init".
228 int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
231 * Filter uninitialization function.
233 * Called only once right before the filter is freed. Should deallocate any
234 * memory held by the filter, release any buffer references, etc. It does
235 * not need to deallocate the AVFilterContext.priv memory itself.
237 * This callback may be called even if @ref AVFilter.init "init" was not
238 * called or failed, so it must be prepared to handle such a situation.
240 void (*uninit)(AVFilterContext *ctx);
243 * Query formats supported by the filter on its inputs and outputs.
245 * This callback is called after the filter is initialized (so the inputs
246 * and outputs are fixed), shortly before the format negotiation. This
247 * callback may be called more than once.
249 * This callback must set AVFilterLink.out_formats on every input link and
250 * AVFilterLink.in_formats on every output link to a list of pixel/sample
251 * formats that the filter supports on that link. For audio links, this
252 * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" /
253 * @ref AVFilterLink.out_samplerates "out_samplerates" and
254 * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" /
255 * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously.
257 * This callback may be NULL for filters with one input, in which case
258 * libavfilter assumes that it supports all input formats and preserves
261 * @return zero on success, a negative value corresponding to an
262 * AVERROR code otherwise
264 int (*query_formats)(AVFilterContext *);
266 int priv_size; ///< size of private data to allocate for the filter
269 * Used by the filter registration system. Must not be touched by any other
272 struct AVFilter *next;
275 * Make the filter instance process a command.
277 * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
278 * @param arg the argument for the command
279 * @param res a buffer with size res_size where the filter(s) can return a response. This must not change when the command is not supported.
280 * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
281 * time consuming then a filter should treat it like an unsupported command
283 * @returns >=0 on success otherwise an error code.
284 * AVERROR(ENOSYS) on unsupported commands
286 int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
289 * Filter initialization function, alternative to the init()
290 * callback. Args contains the user-supplied parameters, opaque is
291 * used for providing binary data.
293 int (*init_opaque)(AVFilterContext *ctx, void *opaque);
297 * Process multiple parts of the frame concurrently.
299 #define AVFILTER_THREAD_SLICE (1 << 0)
301 typedef struct AVFilterInternal AVFilterInternal;
303 /** An instance of a filter */
304 struct AVFilterContext {
305 const AVClass *av_class; ///< needed for av_log() and filters common options
307 const AVFilter *filter; ///< the AVFilter of which this is an instance
309 char *name; ///< name of this filter instance
311 AVFilterPad *input_pads; ///< array of input pads
312 AVFilterLink **inputs; ///< array of pointers to input links
313 unsigned nb_inputs; ///< number of input pads
315 AVFilterPad *output_pads; ///< array of output pads
316 AVFilterLink **outputs; ///< array of pointers to output links
317 unsigned nb_outputs; ///< number of output pads
319 void *priv; ///< private data for use by the filter
321 struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
324 * Type of multithreading being allowed/used. A combination of
325 * AVFILTER_THREAD_* flags.
327 * May be set by the caller before initializing the filter to forbid some
328 * or all kinds of multithreading for this filter. The default is allowing
331 * When the filter is initialized, this field is combined using bit AND with
332 * AVFilterGraph.thread_type to get the final mask used for determining
333 * allowed threading types. I.e. a threading type needs to be set in both
336 * After the filter is initialized, libavfilter sets this field to the
337 * threading type that is actually used (0 for no multithreading).
342 * An opaque struct for libavfilter internal use.
344 AVFilterInternal *internal;
346 struct AVFilterCommand *command_queue;
348 char *enable_str; ///< enable expression string
349 void *enable; ///< parsed expression (AVExpr*)
350 double *var_values; ///< variable values for the enable expression
351 int is_disabled; ///< the enabled state from the last expression evaluation
355 * A link between two filters. This contains pointers to the source and
356 * destination filters between which this link exists, and the indexes of
357 * the pads involved. In addition, this link also contains the parameters
358 * which have been negotiated and agreed upon between the filter, such as
359 * image dimensions, format, etc.
361 struct AVFilterLink {
362 AVFilterContext *src; ///< source filter
363 AVFilterPad *srcpad; ///< output pad on the source filter
365 AVFilterContext *dst; ///< dest filter
366 AVFilterPad *dstpad; ///< input pad on the dest filter
368 enum AVMediaType type; ///< filter media type
370 /* These parameters apply only to video */
371 int w; ///< agreed upon image width
372 int h; ///< agreed upon image height
373 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
374 /* These parameters apply only to audio */
375 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
376 int sample_rate; ///< samples per second
378 int format; ///< agreed upon media format
381 * Define the time base used by the PTS of the frames/samples
382 * which will pass through this link.
383 * During the configuration stage, each filter is supposed to
384 * change only the output timebase, while the timebase of the
385 * input link is assumed to be an unchangeable property.
387 AVRational time_base;
389 /*****************************************************************
390 * All fields below this line are not part of the public API. They
391 * may not be used outside of libavfilter and can be changed and
393 * New public fields should be added right above.
394 *****************************************************************
397 * Lists of formats and channel layouts supported by the input and output
398 * filters respectively. These lists are used for negotiating the format
399 * to actually be used, which will be loaded into the format and
400 * channel_layout members, above, when chosen.
403 AVFilterFormats *in_formats;
404 AVFilterFormats *out_formats;
407 * Lists of channel layouts and sample rates used for automatic
410 AVFilterFormats *in_samplerates;
411 AVFilterFormats *out_samplerates;
412 struct AVFilterChannelLayouts *in_channel_layouts;
413 struct AVFilterChannelLayouts *out_channel_layouts;
416 * Audio only, the destination filter sets this to a non-zero value to
417 * request that buffers with the given number of samples should be sent to
418 * it. AVFilterPad.needs_fifo must also be set on the corresponding input
420 * Last buffer before EOF will be padded with silence.
424 /** stage of the initialization of the link properties (dimensions, etc) */
426 AVLINK_UNINIT = 0, ///< not started
427 AVLINK_STARTINIT, ///< started, but incomplete
428 AVLINK_INIT ///< complete
432 * Graph the filter belongs to.
434 struct AVFilterGraph *graph;
437 * Current timestamp of the link, as defined by the most recent
438 * frame(s), in AV_TIME_BASE units.
443 * Index in the age array.
448 * Frame rate of the stream on the link, or 1/0 if unknown or variable;
449 * if left to 0/0, will be automatically copied from the first input
450 * of the source filter if it exists.
452 * Sources should set it to the best estimation of the real frame rate.
453 * If the source frame rate is unknown or variable, set this to 1/0.
454 * Filters should update it if necessary depending on their function.
455 * Sinks can use it to set a default output frame rate.
456 * It is similar to the r_frame_rate field in AVStream.
458 AVRational frame_rate;
461 * Buffer partially filled with samples to achieve a fixed/minimum size.
463 AVFrame *partial_buf;
466 * Size of the partial buffer to allocate.
467 * Must be between min_samples and max_samples.
469 int partial_buf_size;
472 * Minimum number of samples to filter at once. If filter_frame() is
473 * called with fewer samples, it will accumulate them in partial_buf.
474 * This field and the related ones must not be changed after filtering
476 * If 0, all related fields are ignored.
481 * Maximum number of samples to filter at once. If filter_frame() is
482 * called with more samples, it will split them.
487 * True if the link is closed.
488 * If set, all attempts of start_frame, filter_frame or request_frame
489 * will fail with AVERROR_EOF, and if necessary the reference will be
491 * If request_frame returns AVERROR_EOF, this flag is set on the
492 * corresponding link.
493 * It can be set also be set by either the source or the destination
499 * Number of channels.
504 * Link processing flags.
509 * Number of past frames sent through the link.
515 * Link two filters together.
517 * @param src the source filter
518 * @param srcpad index of the output pad on the source filter
519 * @param dst the destination filter
520 * @param dstpad index of the input pad on the destination filter
521 * @return zero on success
523 int avfilter_link(AVFilterContext *src, unsigned srcpad,
524 AVFilterContext *dst, unsigned dstpad);
527 * Free the link in *link, and set its pointer to NULL.
529 void avfilter_link_free(AVFilterLink **link);
532 * Get the number of channels of a link.
534 int avfilter_link_get_channels(AVFilterLink *link);
537 * Set the closed field of a link.
539 void avfilter_link_set_closed(AVFilterLink *link, int closed);
542 * Negotiate the media format, dimensions, etc of all inputs to a filter.
544 * @param filter the filter to negotiate the properties for its inputs
545 * @return zero on successful negotiation
547 int avfilter_config_links(AVFilterContext *filter);
549 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
550 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
553 * Make the filter instance process a command.
554 * It is recommended to use avfilter_graph_send_command().
556 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
558 /** Initialize the filter system. Register all builtin filters. */
559 void avfilter_register_all(void);
561 #if FF_API_OLD_FILTER_REGISTER
562 /** Uninitialize the filter system. Unregister all filters. */
564 void avfilter_uninit(void);
568 * Register a filter. This is only needed if you plan to use
569 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
570 * filter can still by instantiated with avfilter_graph_alloc_filter even if it
573 * @param filter the filter to register
574 * @return 0 if the registration was successful, a negative value
577 int avfilter_register(AVFilter *filter);
580 * Get a filter definition matching the given name.
582 * @param name the filter name to find
583 * @return the filter definition, if any matching one is registered.
584 * NULL if none found.
586 #if !FF_API_NOCONST_GET_NAME
589 AVFilter *avfilter_get_by_name(const char *name);
592 * Iterate over all registered filters.
593 * @return If prev is non-NULL, next registered filter after prev or NULL if
594 * prev is the last filter. If prev is NULL, return the first registered filter.
596 const AVFilter *avfilter_next(const AVFilter *prev);
598 #if FF_API_OLD_FILTER_REGISTER
600 * If filter is NULL, returns a pointer to the first registered filter pointer,
601 * if filter is non-NULL, returns the next pointer after filter.
602 * If the returned pointer points to NULL, the last registered filter
603 * was already reached.
604 * @deprecated use avfilter_next()
607 AVFilter **av_filter_next(AVFilter **filter);
610 #if FF_API_AVFILTER_OPEN
612 * Create a filter instance.
614 * @param filter_ctx put here a pointer to the created filter context
615 * on success, NULL on failure
616 * @param filter the filter to create an instance of
617 * @param inst_name Name to give to the new instance. Can be NULL for none.
618 * @return >= 0 in case of success, a negative error code otherwise
619 * @deprecated use avfilter_graph_alloc_filter() instead
622 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
626 #if FF_API_AVFILTER_INIT_FILTER
628 * Initialize a filter.
630 * @param filter the filter to initialize
631 * @param args A string of parameters to use when initializing the filter.
632 * The format and meaning of this string varies by filter.
633 * @param opaque Any extra non-string data needed by the filter. The meaning
634 * of this parameter varies by filter.
635 * @return zero on success
638 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
642 * Initialize a filter with the supplied parameters.
644 * @param ctx uninitialized filter context to initialize
645 * @param args Options to initialize the filter with. This must be a
646 * ':'-separated list of options in the 'key=value' form.
647 * May be NULL if the options have been set directly using the
648 * AVOptions API or there are no options that need to be set.
649 * @return 0 on success, a negative AVERROR on failure
651 int avfilter_init_str(AVFilterContext *ctx, const char *args);
654 * Initialize a filter with the supplied dictionary of options.
656 * @param ctx uninitialized filter context to initialize
657 * @param options An AVDictionary filled with options for this filter. On
658 * return this parameter will be destroyed and replaced with
659 * a dict containing options that were not found. This dictionary
660 * must be freed by the caller.
661 * May be NULL, then this function is equivalent to
662 * avfilter_init_str() with the second parameter set to NULL.
663 * @return 0 on success, a negative AVERROR on failure
665 * @note This function and avfilter_init_str() do essentially the same thing,
666 * the difference is in manner in which the options are passed. It is up to the
667 * calling code to choose whichever is more preferable. The two functions also
668 * behave differently when some of the provided options are not declared as
669 * supported by the filter. In such a case, avfilter_init_str() will fail, but
670 * this function will leave those extra options in the options AVDictionary and
673 int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options);
676 * Free a filter context. This will also remove the filter from its
677 * filtergraph's list of filters.
679 * @param filter the filter to free
681 void avfilter_free(AVFilterContext *filter);
684 * Insert a filter in the middle of an existing link.
686 * @param link the link into which the filter should be inserted
687 * @param filt the filter to be inserted
688 * @param filt_srcpad_idx the input pad on the filter to connect
689 * @param filt_dstpad_idx the output pad on the filter to connect
690 * @return zero on success
692 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
693 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
696 * @return AVClass for AVFilterContext.
698 * @see av_opt_find().
700 const AVClass *avfilter_get_class(void);
702 typedef struct AVFilterGraphInternal AVFilterGraphInternal;
705 * A function pointer passed to the @ref AVFilterGraph.execute callback to be
706 * executed multiple times, possibly in parallel.
708 * @param ctx the filter context the job belongs to
709 * @param arg an opaque parameter passed through from @ref
710 * AVFilterGraph.execute
711 * @param jobnr the index of the job being executed
712 * @param nb_jobs the total number of jobs
714 * @return 0 on success, a negative AVERROR on error
716 typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
719 * A function executing multiple jobs, possibly in parallel.
721 * @param ctx the filter context to which the jobs belong
722 * @param func the function to be called multiple times
723 * @param arg the argument to be passed to func
724 * @param ret a nb_jobs-sized array to be filled with return values from each
726 * @param nb_jobs the number of jobs to execute
728 * @return 0 on success, a negative AVERROR on error
730 typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
731 void *arg, int *ret, int nb_jobs);
733 typedef struct AVFilterGraph {
734 const AVClass *av_class;
735 AVFilterContext **filters;
738 char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
739 char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
742 * Type of multithreading allowed for filters in this graph. A combination
743 * of AVFILTER_THREAD_* flags.
745 * May be set by the caller at any point, the setting will apply to all
746 * filters initialized after that. The default is allowing everything.
748 * When a filter in this graph is initialized, this field is combined using
749 * bit AND with AVFilterContext.thread_type to get the final mask used for
750 * determining allowed threading types. I.e. a threading type needs to be
751 * set in both to be allowed.
756 * Maximum number of threads used by filters in this graph. May be set by
757 * the caller before adding any filters to the filtergraph. Zero (the
758 * default) means that the number of threads is determined automatically.
763 * Opaque object for libavfilter internal use.
765 AVFilterGraphInternal *internal;
768 * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
769 * be used from callbacks like @ref AVFilterGraph.execute.
770 * Libavfilter will not touch this field in any way.
775 * This callback may be set by the caller immediately after allocating the
776 * graph and before adding any filters to it, to provide a custom
777 * multithreading implementation.
779 * If set, filters with slice threading capability will call this callback
780 * to execute multiple jobs in parallel.
782 * If this field is left unset, libavfilter will use its internal
783 * implementation, which may or may not be multithreaded depending on the
784 * platform and build options.
786 avfilter_execute_func *execute;
788 char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
793 * The following fields are for internal use only.
794 * Their type, offset, number and semantic can change without notice.
797 AVFilterLink **sink_links;
798 int sink_links_count;
800 unsigned disable_auto_convert;
804 * Allocate a filter graph.
806 * @return the allocated filter graph on success or NULL.
808 AVFilterGraph *avfilter_graph_alloc(void);
811 * Create a new filter instance in a filter graph.
813 * @param graph graph in which the new filter will be used
814 * @param filter the filter to create an instance of
815 * @param name Name to give to the new instance (will be copied to
816 * AVFilterContext.name). This may be used by the caller to identify
817 * different filters, libavfilter itself assigns no semantics to
818 * this parameter. May be NULL.
820 * @return the context of the newly created filter instance (note that it is
821 * also retrievable directly through AVFilterGraph.filters or with
822 * avfilter_graph_get_filter()) on success or NULL on failure.
824 AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
825 const AVFilter *filter,
829 * Get a filter instance identified by instance name from graph.
831 * @param graph filter graph to search through.
832 * @param name filter instance name (should be unique in the graph).
833 * @return the pointer to the found filter instance or NULL if it
836 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, const char *name);
838 #if FF_API_AVFILTER_OPEN
840 * Add an existing filter instance to a filter graph.
842 * @param graphctx the filter graph
843 * @param filter the filter to be added
845 * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a
849 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
853 * Create and add a filter instance into an existing graph.
854 * The filter instance is created from the filter filt and inited
855 * with the parameters args and opaque.
857 * In case of success put in *filt_ctx the pointer to the created
858 * filter instance, otherwise set *filt_ctx to NULL.
860 * @param name the instance name to give to the created filter instance
861 * @param graph_ctx the filter graph
862 * @return a negative AVERROR error code in case of failure, a non
863 * negative value otherwise
865 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
866 const char *name, const char *args, void *opaque,
867 AVFilterGraph *graph_ctx);
870 * Enable or disable automatic format conversion inside the graph.
872 * Note that format conversion can still happen inside explicitly inserted
873 * scale and aresample filters.
875 * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
877 void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags);
880 AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
881 AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
885 * Check validity and configure all the links and formats in the graph.
887 * @param graphctx the filter graph
888 * @param log_ctx context used for logging
889 * @return >= 0 in case of success, a negative AVERROR code otherwise
891 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
894 * Free a graph, destroy its links, and set *graph to NULL.
895 * If *graph is NULL, do nothing.
897 void avfilter_graph_free(AVFilterGraph **graph);
900 * A linked-list of the inputs/outputs of the filter chain.
902 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
903 * where it is used to communicate open (unlinked) inputs and outputs from and
905 * This struct specifies, per each not connected pad contained in the graph, the
906 * filter context and the pad index required for establishing a link.
908 typedef struct AVFilterInOut {
909 /** unique name for this input/output in the list */
912 /** filter context associated to this input/output */
913 AVFilterContext *filter_ctx;
915 /** index of the filt_ctx pad to use for linking */
918 /** next input/input in the list, NULL if this is the last */
919 struct AVFilterInOut *next;
923 * Allocate a single AVFilterInOut entry.
924 * Must be freed with avfilter_inout_free().
925 * @return allocated AVFilterInOut on success, NULL on failure.
927 AVFilterInOut *avfilter_inout_alloc(void);
930 * Free the supplied list of AVFilterInOut and set *inout to NULL.
931 * If *inout is NULL, do nothing.
933 void avfilter_inout_free(AVFilterInOut **inout);
936 * Add a graph described by a string to a graph.
938 * @note The caller must provide the lists of inputs and outputs,
939 * which therefore must be known before calling the function.
941 * @note The inputs parameter describes inputs of the already existing
942 * part of the graph; i.e. from the point of view of the newly created
943 * part, they are outputs. Similarly the outputs parameter describes
944 * outputs of the already existing filters, which are provided as
945 * inputs to the parsed filters.
947 * @param graph the filter graph where to link the parsed graph context
948 * @param filters string to be parsed
949 * @param inputs linked list to the inputs of the graph
950 * @param outputs linked list to the outputs of the graph
951 * @return zero on success, a negative AVERROR code on error
953 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
954 AVFilterInOut *inputs, AVFilterInOut *outputs,
958 * Add a graph described by a string to a graph.
960 * In the graph filters description, if the input label of the first
961 * filter is not specified, "in" is assumed; if the output label of
962 * the last filter is not specified, "out" is assumed.
964 * @param graph the filter graph where to link the parsed graph context
965 * @param filters string to be parsed
966 * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
967 * If non-NULL, *inputs is updated to contain the list of open inputs
968 * after the parsing, should be freed with avfilter_inout_free().
969 * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
970 * If non-NULL, *outputs is updated to contain the list of open outputs
971 * after the parsing, should be freed with avfilter_inout_free().
972 * @return non negative on success, a negative AVERROR code on error
974 int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters,
975 AVFilterInOut **inputs, AVFilterInOut **outputs,
979 * Add a graph described by a string to a graph.
981 * @param[in] graph the filter graph where to link the parsed graph context
982 * @param[in] filters string to be parsed
983 * @param[out] inputs a linked list of all free (unlinked) inputs of the
984 * parsed graph will be returned here. It is to be freed
985 * by the caller using avfilter_inout_free().
986 * @param[out] outputs a linked list of all free (unlinked) outputs of the
987 * parsed graph will be returned here. It is to be freed by the
988 * caller using avfilter_inout_free().
989 * @return zero on success, a negative AVERROR code on error
991 * @note This function returns the inputs and outputs that are left
992 * unlinked after parsing the graph and the caller then deals with
994 * @note This function makes no reference whatsoever to already
995 * existing parts of the graph and the inputs parameter will on return
996 * contain inputs of the newly parsed part of the graph. Analogously
997 * the outputs parameter will contain outputs of the newly created
1000 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
1001 AVFilterInOut **inputs,
1002 AVFilterInOut **outputs);
1005 * Send a command to one or more filter instances.
1007 * @param graph the filter graph
1008 * @param target the filter(s) to which the command should be sent
1009 * "all" sends to all filters
1010 * otherwise it can be a filter or filter instance name
1011 * which will send the command to all matching filters.
1012 * @param cmd the command to send, for handling simplicity all commands must be alphanumeric only
1013 * @param arg the argument for the command
1014 * @param res a buffer with size res_size where the filter(s) can return a response.
1016 * @returns >=0 on success otherwise an error code.
1017 * AVERROR(ENOSYS) on unsupported commands
1019 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
1022 * Queue a command for one or more filter instances.
1024 * @param graph the filter graph
1025 * @param target the filter(s) to which the command should be sent
1026 * "all" sends to all filters
1027 * otherwise it can be a filter or filter instance name
1028 * which will send the command to all matching filters.
1029 * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
1030 * @param arg the argument for the command
1031 * @param ts time at which the command should be sent to the filter
1033 * @note As this executes commands after this function returns, no return code
1034 * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
1036 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
1040 * Dump a graph into a human-readable string representation.
1042 * @param graph the graph to dump
1043 * @param options formatting options; currently ignored
1044 * @return a string, or NULL in case of memory allocation failure;
1045 * the string must be freed using av_free
1047 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
1050 * Request a frame on the oldest sink link.
1052 * If the request returns AVERROR_EOF, try the next.
1054 * Note that this function is not meant to be the sole scheduling mechanism
1055 * of a filtergraph, only a convenience function to help drain a filtergraph
1056 * in a balanced way under normal circumstances.
1058 * Also note that AVERROR_EOF does not mean that frames did not arrive on
1059 * some of the sinks during the process.
1060 * When there are multiple sink links, in case the requested link
1061 * returns an EOF, this may cause a filter to flush pending frames
1062 * which are sent to another sink link, although unrequested.
1064 * @return the return value of ff_request_frame(),
1065 * or AVERROR_EOF if all links returned AVERROR_EOF
1067 int avfilter_graph_request_oldest(AVFilterGraph *graph);
1073 #endif /* AVFILTER_AVFILTER_H */