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/buffer.h"
41 #include "libavutil/dict.h"
42 #include "libavutil/frame.h"
43 #include "libavutil/log.h"
44 #include "libavutil/samplefmt.h"
45 #include "libavutil/pixfmt.h"
46 #include "libavutil/rational.h"
48 #include "libavfilter/version.h"
51 * Return the LIBAVFILTER_VERSION_INT constant.
53 unsigned avfilter_version(void);
56 * Return the libavfilter build-time configuration.
58 const char *avfilter_configuration(void);
61 * Return the libavfilter license.
63 const char *avfilter_license(void);
65 typedef struct AVFilterContext AVFilterContext;
66 typedef struct AVFilterLink AVFilterLink;
67 typedef struct AVFilterPad AVFilterPad;
68 typedef struct AVFilterFormats AVFilterFormats;
71 * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
72 * AVFilter.inputs/outputs).
74 int avfilter_pad_count(const AVFilterPad *pads);
77 * Get the name of an AVFilterPad.
79 * @param pads an array of AVFilterPads
80 * @param pad_idx index of the pad in the array it; is the caller's
81 * responsibility to ensure the index is valid
83 * @return name of the pad_idx'th pad in pads
85 const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
88 * Get the type of an AVFilterPad.
90 * @param pads an array of AVFilterPads
91 * @param pad_idx index of the pad in the array; it is the caller's
92 * responsibility to ensure the index is valid
94 * @return type of the pad_idx'th pad in pads
96 enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
99 * The number of the filter inputs is not determined just by AVFilter.inputs.
100 * The filter might add additional inputs during initialization depending on the
101 * options supplied to it.
103 #define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
105 * The number of the filter outputs is not determined just by AVFilter.outputs.
106 * The filter might add additional outputs during initialization depending on
107 * the options supplied to it.
109 #define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
111 * The filter supports multithreading by splitting frames into multiple parts
112 * and processing them concurrently.
114 #define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
116 * Some filters support a generic "enable" expression option that can be used
117 * to enable or disable a filter in the timeline. Filters supporting this
118 * option have this flag set. When the enable expression is false, the default
119 * no-op filter_frame() function is called in place of the filter_frame()
120 * callback defined on each input pad, thus the frame is passed unchanged to
123 #define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16)
125 * Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will
126 * have its filter_frame() callback(s) called as usual even when the enable
127 * expression is false. The filter will disable filtering within the
128 * filter_frame() callback(s) itself, for example executing code depending on
129 * the AVFilterContext->is_disabled value.
131 #define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)
133 * Handy mask to test whether the filter supports or no the timeline feature
134 * (internally or generically).
136 #define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)
139 * Filter definition. This defines the pads a filter contains, and all the
140 * callback functions used to interact with the filter.
142 typedef struct AVFilter {
144 * Filter name. Must be non-NULL and unique among filters.
149 * A description of the filter. May be NULL.
151 * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
153 const char *description;
156 * List of inputs, terminated by a zeroed element.
158 * NULL if there are no (static) inputs. Instances of filters with
159 * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in
162 const AVFilterPad *inputs;
164 * List of outputs, terminated by a zeroed element.
166 * NULL if there are no (static) outputs. Instances of filters with
167 * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in
170 const AVFilterPad *outputs;
173 * A class for the private data, used to declare filter private AVOptions.
174 * This field is NULL for filters that do not declare any options.
176 * If this field is non-NULL, the first member of the filter private data
177 * must be a pointer to AVClass, which will be set by libavfilter generic
178 * code to this class.
180 const AVClass *priv_class;
183 * A combination of AVFILTER_FLAG_*
187 /*****************************************************************
188 * All fields below this line are not part of the public API. They
189 * may not be used outside of libavfilter and can be changed and
191 * New public fields should be added right above.
192 *****************************************************************
196 * Filter initialization function.
198 * This callback will be called only once during the filter lifetime, after
199 * all the options have been set, but before links between filters are
200 * established and format negotiation is done.
202 * Basic filter initialization should be done here. Filters with dynamic
203 * inputs and/or outputs should create those inputs/outputs here based on
204 * provided options. No more changes to this filter's inputs/outputs can be
205 * done after this callback.
207 * This callback must not assume that the filter links exist or frame
208 * parameters are known.
210 * @ref AVFilter.uninit "uninit" is guaranteed to be called even if
211 * initialization fails, so this callback does not have to clean up on
214 * @return 0 on success, a negative AVERROR on failure
216 int (*init)(AVFilterContext *ctx);
219 * Should be set instead of @ref AVFilter.init "init" by the filters that
220 * want to pass a dictionary of AVOptions to nested contexts that are
221 * allocated during init.
223 * On return, the options dict should be freed and replaced with one that
224 * contains all the options which could not be processed by this filter (or
225 * with NULL if all the options were processed).
227 * Otherwise the semantics is the same as for @ref AVFilter.init "init".
229 int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
232 * Filter uninitialization function.
234 * Called only once right before the filter is freed. Should deallocate any
235 * memory held by the filter, release any buffer references, etc. It does
236 * not need to deallocate the AVFilterContext.priv memory itself.
238 * This callback may be called even if @ref AVFilter.init "init" was not
239 * called or failed, so it must be prepared to handle such a situation.
241 void (*uninit)(AVFilterContext *ctx);
244 * Query formats supported by the filter on its inputs and outputs.
246 * This callback is called after the filter is initialized (so the inputs
247 * and outputs are fixed), shortly before the format negotiation. This
248 * callback may be called more than once.
250 * This callback must set AVFilterLink.out_formats on every input link and
251 * AVFilterLink.in_formats on every output link to a list of pixel/sample
252 * formats that the filter supports on that link. For audio links, this
253 * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" /
254 * @ref AVFilterLink.out_samplerates "out_samplerates" and
255 * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" /
256 * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously.
258 * This callback may be NULL for filters with one input, in which case
259 * libavfilter assumes that it supports all input formats and preserves
262 * @return zero on success, a negative value corresponding to an
263 * AVERROR code otherwise
265 int (*query_formats)(AVFilterContext *);
267 int priv_size; ///< size of private data to allocate for the filter
270 * Used by the filter registration system. Must not be touched by any other
273 struct AVFilter *next;
276 * Make the filter instance process a command.
278 * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
279 * @param arg the argument for the command
280 * @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.
281 * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
282 * time consuming then a filter should treat it like an unsupported command
284 * @returns >=0 on success otherwise an error code.
285 * AVERROR(ENOSYS) on unsupported commands
287 int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
290 * Filter initialization function, alternative to the init()
291 * callback. Args contains the user-supplied parameters, opaque is
292 * used for providing binary data.
294 int (*init_opaque)(AVFilterContext *ctx, void *opaque);
298 * Process multiple parts of the frame concurrently.
300 #define AVFILTER_THREAD_SLICE (1 << 0)
302 typedef struct AVFilterInternal AVFilterInternal;
304 /** An instance of a filter */
305 struct AVFilterContext {
306 const AVClass *av_class; ///< needed for av_log() and filters common options
308 const AVFilter *filter; ///< the AVFilter of which this is an instance
310 char *name; ///< name of this filter instance
312 AVFilterPad *input_pads; ///< array of input pads
313 AVFilterLink **inputs; ///< array of pointers to input links
314 unsigned nb_inputs; ///< number of input pads
316 AVFilterPad *output_pads; ///< array of output pads
317 AVFilterLink **outputs; ///< array of pointers to output links
318 unsigned nb_outputs; ///< number of output pads
320 void *priv; ///< private data for use by the filter
322 struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
325 * Type of multithreading being allowed/used. A combination of
326 * AVFILTER_THREAD_* flags.
328 * May be set by the caller before initializing the filter to forbid some
329 * or all kinds of multithreading for this filter. The default is allowing
332 * When the filter is initialized, this field is combined using bit AND with
333 * AVFilterGraph.thread_type to get the final mask used for determining
334 * allowed threading types. I.e. a threading type needs to be set in both
337 * After the filter is initialized, libavfilter sets this field to the
338 * threading type that is actually used (0 for no multithreading).
343 * An opaque struct for libavfilter internal use.
345 AVFilterInternal *internal;
347 struct AVFilterCommand *command_queue;
349 char *enable_str; ///< enable expression string
350 void *enable; ///< parsed expression (AVExpr*)
351 double *var_values; ///< variable values for the enable expression
352 int is_disabled; ///< the enabled state from the last expression evaluation
356 * A link between two filters. This contains pointers to the source and
357 * destination filters between which this link exists, and the indexes of
358 * the pads involved. In addition, this link also contains the parameters
359 * which have been negotiated and agreed upon between the filter, such as
360 * image dimensions, format, etc.
362 struct AVFilterLink {
363 AVFilterContext *src; ///< source filter
364 AVFilterPad *srcpad; ///< output pad on the source filter
366 AVFilterContext *dst; ///< dest filter
367 AVFilterPad *dstpad; ///< input pad on the dest filter
369 enum AVMediaType type; ///< filter media type
371 /* These parameters apply only to video */
372 int w; ///< agreed upon image width
373 int h; ///< agreed upon image height
374 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
375 /* These parameters apply only to audio */
376 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
377 int sample_rate; ///< samples per second
379 int format; ///< agreed upon media format
382 * Define the time base used by the PTS of the frames/samples
383 * which will pass through this link.
384 * During the configuration stage, each filter is supposed to
385 * change only the output timebase, while the timebase of the
386 * input link is assumed to be an unchangeable property.
388 AVRational time_base;
390 /*****************************************************************
391 * All fields below this line are not part of the public API. They
392 * may not be used outside of libavfilter and can be changed and
394 * New public fields should be added right above.
395 *****************************************************************
398 * Lists of formats and channel layouts supported by the input and output
399 * filters respectively. These lists are used for negotiating the format
400 * to actually be used, which will be loaded into the format and
401 * channel_layout members, above, when chosen.
404 AVFilterFormats *in_formats;
405 AVFilterFormats *out_formats;
408 * Lists of channel layouts and sample rates used for automatic
411 AVFilterFormats *in_samplerates;
412 AVFilterFormats *out_samplerates;
413 struct AVFilterChannelLayouts *in_channel_layouts;
414 struct AVFilterChannelLayouts *out_channel_layouts;
417 * Audio only, the destination filter sets this to a non-zero value to
418 * request that buffers with the given number of samples should be sent to
419 * it. AVFilterPad.needs_fifo must also be set on the corresponding input
421 * Last buffer before EOF will be padded with silence.
425 /** stage of the initialization of the link properties (dimensions, etc) */
427 AVLINK_UNINIT = 0, ///< not started
428 AVLINK_STARTINIT, ///< started, but incomplete
429 AVLINK_INIT ///< complete
433 * Graph the filter belongs to.
435 struct AVFilterGraph *graph;
438 * Current timestamp of the link, as defined by the most recent
439 * frame(s), in link time_base units.
444 * Current timestamp of the link, as defined by the most recent
445 * frame(s), in AV_TIME_BASE units.
447 int64_t current_pts_us;
450 * Index in the age array.
455 * Frame rate of the stream on the link, or 1/0 if unknown or variable;
456 * if left to 0/0, will be automatically copied from the first input
457 * of the source filter if it exists.
459 * Sources should set it to the best estimation of the real frame rate.
460 * If the source frame rate is unknown or variable, set this to 1/0.
461 * Filters should update it if necessary depending on their function.
462 * Sinks can use it to set a default output frame rate.
463 * It is similar to the r_frame_rate field in AVStream.
465 AVRational frame_rate;
468 * For hwaccel pixel formats, this should be a reference to the
469 * AVHWFramesContext describing the frames.
471 AVBufferRef *hw_frames_ctx;
474 * Buffer partially filled with samples to achieve a fixed/minimum size.
476 AVFrame *partial_buf;
479 * Size of the partial buffer to allocate.
480 * Must be between min_samples and max_samples.
482 int partial_buf_size;
485 * Minimum number of samples to filter at once. If filter_frame() is
486 * called with fewer samples, it will accumulate them in partial_buf.
487 * This field and the related ones must not be changed after filtering
489 * If 0, all related fields are ignored.
494 * Maximum number of samples to filter at once. If filter_frame() is
495 * called with more samples, it will split them.
501 * If not zero, all attempts of filter_frame or request_frame
502 * will fail with the corresponding code, and if necessary the reference
504 * If request_frame returns an error, the status is set on the
505 * corresponding link.
506 * It can be set also be set by either the source or the destination
512 * Number of channels.
517 * Link processing flags.
522 * Number of past frames sent through the link.
527 * A pointer to a FFVideoFramePool struct.
529 void *video_frame_pool;
532 * True if a frame is currently wanted on the input of this filter.
533 * Set when ff_request_frame() is called by the output,
534 * cleared when the request is handled or forwarded.
539 * True if a frame is currently wanted on the output of this filter.
540 * Set when ff_request_frame() is called by the output,
541 * cleared when a frame is filtered.
543 int frame_wanted_out;
547 * Link two filters together.
549 * @param src the source filter
550 * @param srcpad index of the output pad on the source filter
551 * @param dst the destination filter
552 * @param dstpad index of the input pad on the destination filter
553 * @return zero on success
555 int avfilter_link(AVFilterContext *src, unsigned srcpad,
556 AVFilterContext *dst, unsigned dstpad);
559 * Free the link in *link, and set its pointer to NULL.
561 void avfilter_link_free(AVFilterLink **link);
564 * Get the number of channels of a link.
566 int avfilter_link_get_channels(AVFilterLink *link);
569 * Set the closed field of a link.
570 * @deprecated applications are not supposed to mess with links, they should
574 void avfilter_link_set_closed(AVFilterLink *link, int closed);
577 * Negotiate the media format, dimensions, etc of all inputs to a filter.
579 * @param filter the filter to negotiate the properties for its inputs
580 * @return zero on successful negotiation
582 int avfilter_config_links(AVFilterContext *filter);
584 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
585 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
588 * Make the filter instance process a command.
589 * It is recommended to use avfilter_graph_send_command().
591 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
593 /** Initialize the filter system. Register all builtin filters. */
594 void avfilter_register_all(void);
596 #if FF_API_OLD_FILTER_REGISTER
597 /** Uninitialize the filter system. Unregister all filters. */
599 void avfilter_uninit(void);
603 * Register a filter. This is only needed if you plan to use
604 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
605 * filter can still by instantiated with avfilter_graph_alloc_filter even if it
608 * @param filter the filter to register
609 * @return 0 if the registration was successful, a negative value
612 int avfilter_register(AVFilter *filter);
615 * Get a filter definition matching the given name.
617 * @param name the filter name to find
618 * @return the filter definition, if any matching one is registered.
619 * NULL if none found.
621 #if !FF_API_NOCONST_GET_NAME
624 AVFilter *avfilter_get_by_name(const char *name);
627 * Iterate over all registered filters.
628 * @return If prev is non-NULL, next registered filter after prev or NULL if
629 * prev is the last filter. If prev is NULL, return the first registered filter.
631 const AVFilter *avfilter_next(const AVFilter *prev);
633 #if FF_API_OLD_FILTER_REGISTER
635 * If filter is NULL, returns a pointer to the first registered filter pointer,
636 * if filter is non-NULL, returns the next pointer after filter.
637 * If the returned pointer points to NULL, the last registered filter
638 * was already reached.
639 * @deprecated use avfilter_next()
642 AVFilter **av_filter_next(AVFilter **filter);
645 #if FF_API_AVFILTER_OPEN
647 * Create a filter instance.
649 * @param filter_ctx put here a pointer to the created filter context
650 * on success, NULL on failure
651 * @param filter the filter to create an instance of
652 * @param inst_name Name to give to the new instance. Can be NULL for none.
653 * @return >= 0 in case of success, a negative error code otherwise
654 * @deprecated use avfilter_graph_alloc_filter() instead
657 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
661 #if FF_API_AVFILTER_INIT_FILTER
663 * Initialize a filter.
665 * @param filter the filter to initialize
666 * @param args A string of parameters to use when initializing the filter.
667 * The format and meaning of this string varies by filter.
668 * @param opaque Any extra non-string data needed by the filter. The meaning
669 * of this parameter varies by filter.
670 * @return zero on success
673 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
677 * Initialize a filter with the supplied parameters.
679 * @param ctx uninitialized filter context to initialize
680 * @param args Options to initialize the filter with. This must be a
681 * ':'-separated list of options in the 'key=value' form.
682 * May be NULL if the options have been set directly using the
683 * AVOptions API or there are no options that need to be set.
684 * @return 0 on success, a negative AVERROR on failure
686 int avfilter_init_str(AVFilterContext *ctx, const char *args);
689 * Initialize a filter with the supplied dictionary of options.
691 * @param ctx uninitialized filter context to initialize
692 * @param options An AVDictionary filled with options for this filter. On
693 * return this parameter will be destroyed and replaced with
694 * a dict containing options that were not found. This dictionary
695 * must be freed by the caller.
696 * May be NULL, then this function is equivalent to
697 * avfilter_init_str() with the second parameter set to NULL.
698 * @return 0 on success, a negative AVERROR on failure
700 * @note This function and avfilter_init_str() do essentially the same thing,
701 * the difference is in manner in which the options are passed. It is up to the
702 * calling code to choose whichever is more preferable. The two functions also
703 * behave differently when some of the provided options are not declared as
704 * supported by the filter. In such a case, avfilter_init_str() will fail, but
705 * this function will leave those extra options in the options AVDictionary and
708 int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options);
711 * Free a filter context. This will also remove the filter from its
712 * filtergraph's list of filters.
714 * @param filter the filter to free
716 void avfilter_free(AVFilterContext *filter);
719 * Insert a filter in the middle of an existing link.
721 * @param link the link into which the filter should be inserted
722 * @param filt the filter to be inserted
723 * @param filt_srcpad_idx the input pad on the filter to connect
724 * @param filt_dstpad_idx the output pad on the filter to connect
725 * @return zero on success
727 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
728 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
731 * @return AVClass for AVFilterContext.
733 * @see av_opt_find().
735 const AVClass *avfilter_get_class(void);
737 typedef struct AVFilterGraphInternal AVFilterGraphInternal;
740 * A function pointer passed to the @ref AVFilterGraph.execute callback to be
741 * executed multiple times, possibly in parallel.
743 * @param ctx the filter context the job belongs to
744 * @param arg an opaque parameter passed through from @ref
745 * AVFilterGraph.execute
746 * @param jobnr the index of the job being executed
747 * @param nb_jobs the total number of jobs
749 * @return 0 on success, a negative AVERROR on error
751 typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
754 * A function executing multiple jobs, possibly in parallel.
756 * @param ctx the filter context to which the jobs belong
757 * @param func the function to be called multiple times
758 * @param arg the argument to be passed to func
759 * @param ret a nb_jobs-sized array to be filled with return values from each
761 * @param nb_jobs the number of jobs to execute
763 * @return 0 on success, a negative AVERROR on error
765 typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
766 void *arg, int *ret, int nb_jobs);
768 typedef struct AVFilterGraph {
769 const AVClass *av_class;
770 AVFilterContext **filters;
773 char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
774 char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
777 * Type of multithreading allowed for filters in this graph. A combination
778 * of AVFILTER_THREAD_* flags.
780 * May be set by the caller at any point, the setting will apply to all
781 * filters initialized after that. The default is allowing everything.
783 * When a filter in this graph is initialized, this field is combined using
784 * bit AND with AVFilterContext.thread_type to get the final mask used for
785 * determining allowed threading types. I.e. a threading type needs to be
786 * set in both to be allowed.
791 * Maximum number of threads used by filters in this graph. May be set by
792 * the caller before adding any filters to the filtergraph. Zero (the
793 * default) means that the number of threads is determined automatically.
798 * Opaque object for libavfilter internal use.
800 AVFilterGraphInternal *internal;
803 * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
804 * be used from callbacks like @ref AVFilterGraph.execute.
805 * Libavfilter will not touch this field in any way.
810 * This callback may be set by the caller immediately after allocating the
811 * graph and before adding any filters to it, to provide a custom
812 * multithreading implementation.
814 * If set, filters with slice threading capability will call this callback
815 * to execute multiple jobs in parallel.
817 * If this field is left unset, libavfilter will use its internal
818 * implementation, which may or may not be multithreaded depending on the
819 * platform and build options.
821 avfilter_execute_func *execute;
823 char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
828 * The following fields are for internal use only.
829 * Their type, offset, number and semantic can change without notice.
832 AVFilterLink **sink_links;
833 int sink_links_count;
835 unsigned disable_auto_convert;
839 * Allocate a filter graph.
841 * @return the allocated filter graph on success or NULL.
843 AVFilterGraph *avfilter_graph_alloc(void);
846 * Create a new filter instance in a filter graph.
848 * @param graph graph in which the new filter will be used
849 * @param filter the filter to create an instance of
850 * @param name Name to give to the new instance (will be copied to
851 * AVFilterContext.name). This may be used by the caller to identify
852 * different filters, libavfilter itself assigns no semantics to
853 * this parameter. May be NULL.
855 * @return the context of the newly created filter instance (note that it is
856 * also retrievable directly through AVFilterGraph.filters or with
857 * avfilter_graph_get_filter()) on success or NULL on failure.
859 AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
860 const AVFilter *filter,
864 * Get a filter instance identified by instance name from graph.
866 * @param graph filter graph to search through.
867 * @param name filter instance name (should be unique in the graph).
868 * @return the pointer to the found filter instance or NULL if it
871 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, const char *name);
873 #if FF_API_AVFILTER_OPEN
875 * Add an existing filter instance to a filter graph.
877 * @param graphctx the filter graph
878 * @param filter the filter to be added
880 * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a
884 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
888 * Create and add a filter instance into an existing graph.
889 * The filter instance is created from the filter filt and inited
890 * with the parameters args and opaque.
892 * In case of success put in *filt_ctx the pointer to the created
893 * filter instance, otherwise set *filt_ctx to NULL.
895 * @param name the instance name to give to the created filter instance
896 * @param graph_ctx the filter graph
897 * @return a negative AVERROR error code in case of failure, a non
898 * negative value otherwise
900 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
901 const char *name, const char *args, void *opaque,
902 AVFilterGraph *graph_ctx);
905 * Enable or disable automatic format conversion inside the graph.
907 * Note that format conversion can still happen inside explicitly inserted
908 * scale and aresample filters.
910 * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
912 void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags);
915 AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
916 AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
920 * Check validity and configure all the links and formats in the graph.
922 * @param graphctx the filter graph
923 * @param log_ctx context used for logging
924 * @return >= 0 in case of success, a negative AVERROR code otherwise
926 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
929 * Free a graph, destroy its links, and set *graph to NULL.
930 * If *graph is NULL, do nothing.
932 void avfilter_graph_free(AVFilterGraph **graph);
935 * A linked-list of the inputs/outputs of the filter chain.
937 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
938 * where it is used to communicate open (unlinked) inputs and outputs from and
940 * This struct specifies, per each not connected pad contained in the graph, the
941 * filter context and the pad index required for establishing a link.
943 typedef struct AVFilterInOut {
944 /** unique name for this input/output in the list */
947 /** filter context associated to this input/output */
948 AVFilterContext *filter_ctx;
950 /** index of the filt_ctx pad to use for linking */
953 /** next input/input in the list, NULL if this is the last */
954 struct AVFilterInOut *next;
958 * Allocate a single AVFilterInOut entry.
959 * Must be freed with avfilter_inout_free().
960 * @return allocated AVFilterInOut on success, NULL on failure.
962 AVFilterInOut *avfilter_inout_alloc(void);
965 * Free the supplied list of AVFilterInOut and set *inout to NULL.
966 * If *inout is NULL, do nothing.
968 void avfilter_inout_free(AVFilterInOut **inout);
971 * Add a graph described by a string to a graph.
973 * @note The caller must provide the lists of inputs and outputs,
974 * which therefore must be known before calling the function.
976 * @note The inputs parameter describes inputs of the already existing
977 * part of the graph; i.e. from the point of view of the newly created
978 * part, they are outputs. Similarly the outputs parameter describes
979 * outputs of the already existing filters, which are provided as
980 * inputs to the parsed filters.
982 * @param graph the filter graph where to link the parsed graph context
983 * @param filters string to be parsed
984 * @param inputs linked list to the inputs of the graph
985 * @param outputs linked list to the outputs of the graph
986 * @return zero on success, a negative AVERROR code on error
988 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
989 AVFilterInOut *inputs, AVFilterInOut *outputs,
993 * Add a graph described by a string to a graph.
995 * In the graph filters description, if the input label of the first
996 * filter is not specified, "in" is assumed; if the output label of
997 * the last filter is not specified, "out" is assumed.
999 * @param graph the filter graph where to link the parsed graph context
1000 * @param filters string to be parsed
1001 * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
1002 * If non-NULL, *inputs is updated to contain the list of open inputs
1003 * after the parsing, should be freed with avfilter_inout_free().
1004 * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
1005 * If non-NULL, *outputs is updated to contain the list of open outputs
1006 * after the parsing, should be freed with avfilter_inout_free().
1007 * @return non negative on success, a negative AVERROR code on error
1009 int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters,
1010 AVFilterInOut **inputs, AVFilterInOut **outputs,
1014 * Add a graph described by a string to a graph.
1016 * @param[in] graph the filter graph where to link the parsed graph context
1017 * @param[in] filters string to be parsed
1018 * @param[out] inputs a linked list of all free (unlinked) inputs of the
1019 * parsed graph will be returned here. It is to be freed
1020 * by the caller using avfilter_inout_free().
1021 * @param[out] outputs a linked list of all free (unlinked) outputs of the
1022 * parsed graph will be returned here. It is to be freed by the
1023 * caller using avfilter_inout_free().
1024 * @return zero on success, a negative AVERROR code on error
1026 * @note This function returns the inputs and outputs that are left
1027 * unlinked after parsing the graph and the caller then deals with
1029 * @note This function makes no reference whatsoever to already
1030 * existing parts of the graph and the inputs parameter will on return
1031 * contain inputs of the newly parsed part of the graph. Analogously
1032 * the outputs parameter will contain outputs of the newly created
1035 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
1036 AVFilterInOut **inputs,
1037 AVFilterInOut **outputs);
1040 * Send a command to one or more filter instances.
1042 * @param graph the filter graph
1043 * @param target the filter(s) to which the command should be sent
1044 * "all" sends to all filters
1045 * otherwise it can be a filter or filter instance name
1046 * which will send the command to all matching filters.
1047 * @param cmd the command to send, for handling simplicity all commands must be alphanumeric only
1048 * @param arg the argument for the command
1049 * @param res a buffer with size res_size where the filter(s) can return a response.
1051 * @returns >=0 on success otherwise an error code.
1052 * AVERROR(ENOSYS) on unsupported commands
1054 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
1057 * Queue a command for one or more filter instances.
1059 * @param graph the filter graph
1060 * @param target the filter(s) to which the command should be sent
1061 * "all" sends to all filters
1062 * otherwise it can be a filter or filter instance name
1063 * which will send the command to all matching filters.
1064 * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
1065 * @param arg the argument for the command
1066 * @param ts time at which the command should be sent to the filter
1068 * @note As this executes commands after this function returns, no return code
1069 * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
1071 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
1075 * Dump a graph into a human-readable string representation.
1077 * @param graph the graph to dump
1078 * @param options formatting options; currently ignored
1079 * @return a string, or NULL in case of memory allocation failure;
1080 * the string must be freed using av_free
1082 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
1085 * Request a frame on the oldest sink link.
1087 * If the request returns AVERROR_EOF, try the next.
1089 * Note that this function is not meant to be the sole scheduling mechanism
1090 * of a filtergraph, only a convenience function to help drain a filtergraph
1091 * in a balanced way under normal circumstances.
1093 * Also note that AVERROR_EOF does not mean that frames did not arrive on
1094 * some of the sinks during the process.
1095 * When there are multiple sink links, in case the requested link
1096 * returns an EOF, this may cause a filter to flush pending frames
1097 * which are sent to another sink link, although unrequested.
1099 * @return the return value of ff_request_frame(),
1100 * or AVERROR_EOF if all links returned AVERROR_EOF
1102 int avfilter_graph_request_oldest(AVFilterGraph *graph);
1108 #endif /* AVFILTER_AVFILTER_H */