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;
348 * For filters which will create hardware frames, sets the device the
349 * filter should create them in. All other filters will ignore this field:
350 * in particular, a filter which consumes or processes hardware frames will
351 * instead use the hw_frames_ctx field in AVFilterLink to carry the
352 * hardware context information.
354 AVBufferRef *hw_device_ctx;
356 struct AVFilterCommand *command_queue;
358 char *enable_str; ///< enable expression string
359 void *enable; ///< parsed expression (AVExpr*)
360 double *var_values; ///< variable values for the enable expression
361 int is_disabled; ///< the enabled state from the last expression evaluation
365 * A link between two filters. This contains pointers to the source and
366 * destination filters between which this link exists, and the indexes of
367 * the pads involved. In addition, this link also contains the parameters
368 * which have been negotiated and agreed upon between the filter, such as
369 * image dimensions, format, etc.
371 struct AVFilterLink {
372 AVFilterContext *src; ///< source filter
373 AVFilterPad *srcpad; ///< output pad on the source filter
375 AVFilterContext *dst; ///< dest filter
376 AVFilterPad *dstpad; ///< input pad on the dest filter
378 enum AVMediaType type; ///< filter media type
380 /* These parameters apply only to video */
381 int w; ///< agreed upon image width
382 int h; ///< agreed upon image height
383 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
384 /* These parameters apply only to audio */
385 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
386 int sample_rate; ///< samples per second
388 int format; ///< agreed upon media format
391 * Define the time base used by the PTS of the frames/samples
392 * which will pass through this link.
393 * During the configuration stage, each filter is supposed to
394 * change only the output timebase, while the timebase of the
395 * input link is assumed to be an unchangeable property.
397 AVRational time_base;
399 /*****************************************************************
400 * All fields below this line are not part of the public API. They
401 * may not be used outside of libavfilter and can be changed and
403 * New public fields should be added right above.
404 *****************************************************************
407 * Lists of formats and channel layouts supported by the input and output
408 * filters respectively. These lists are used for negotiating the format
409 * to actually be used, which will be loaded into the format and
410 * channel_layout members, above, when chosen.
413 AVFilterFormats *in_formats;
414 AVFilterFormats *out_formats;
417 * Lists of channel layouts and sample rates used for automatic
420 AVFilterFormats *in_samplerates;
421 AVFilterFormats *out_samplerates;
422 struct AVFilterChannelLayouts *in_channel_layouts;
423 struct AVFilterChannelLayouts *out_channel_layouts;
426 * Audio only, the destination filter sets this to a non-zero value to
427 * request that buffers with the given number of samples should be sent to
428 * it. AVFilterPad.needs_fifo must also be set on the corresponding input
430 * Last buffer before EOF will be padded with silence.
434 /** stage of the initialization of the link properties (dimensions, etc) */
436 AVLINK_UNINIT = 0, ///< not started
437 AVLINK_STARTINIT, ///< started, but incomplete
438 AVLINK_INIT ///< complete
442 * Graph the filter belongs to.
444 struct AVFilterGraph *graph;
447 * Current timestamp of the link, as defined by the most recent
448 * frame(s), in link time_base units.
453 * Current timestamp of the link, as defined by the most recent
454 * frame(s), in AV_TIME_BASE units.
456 int64_t current_pts_us;
459 * Index in the age array.
464 * Frame rate of the stream on the link, or 1/0 if unknown or variable;
465 * if left to 0/0, will be automatically copied from the first input
466 * of the source filter if it exists.
468 * Sources should set it to the best estimation of the real frame rate.
469 * If the source frame rate is unknown or variable, set this to 1/0.
470 * Filters should update it if necessary depending on their function.
471 * Sinks can use it to set a default output frame rate.
472 * It is similar to the r_frame_rate field in AVStream.
474 AVRational frame_rate;
477 * For hwaccel pixel formats, this should be a reference to the
478 * AVHWFramesContext describing the frames.
480 AVBufferRef *hw_frames_ctx;
483 * Buffer partially filled with samples to achieve a fixed/minimum size.
485 AVFrame *partial_buf;
488 * Size of the partial buffer to allocate.
489 * Must be between min_samples and max_samples.
491 int partial_buf_size;
494 * Minimum number of samples to filter at once. If filter_frame() is
495 * called with fewer samples, it will accumulate them in partial_buf.
496 * This field and the related ones must not be changed after filtering
498 * If 0, all related fields are ignored.
503 * Maximum number of samples to filter at once. If filter_frame() is
504 * called with more samples, it will split them.
510 * If not zero, all attempts of filter_frame or request_frame
511 * will fail with the corresponding code, and if necessary the reference
513 * If request_frame returns an error, the status is set on the
514 * corresponding link.
515 * It can be set also be set by either the source or the destination
521 * Number of channels.
526 * Link processing flags.
531 * Number of past frames sent through the link.
536 * A pointer to a FFVideoFramePool struct.
538 void *video_frame_pool;
541 * True if a frame is currently wanted on the input of this filter.
542 * Set when ff_request_frame() is called by the output,
543 * cleared when the request is handled or forwarded.
548 * True if a frame is currently wanted on the output of this filter.
549 * Set when ff_request_frame() is called by the output,
550 * cleared when a frame is filtered.
552 int frame_wanted_out;
556 * Link two filters together.
558 * @param src the source filter
559 * @param srcpad index of the output pad on the source filter
560 * @param dst the destination filter
561 * @param dstpad index of the input pad on the destination filter
562 * @return zero on success
564 int avfilter_link(AVFilterContext *src, unsigned srcpad,
565 AVFilterContext *dst, unsigned dstpad);
568 * Free the link in *link, and set its pointer to NULL.
570 void avfilter_link_free(AVFilterLink **link);
573 * Get the number of channels of a link.
575 int avfilter_link_get_channels(AVFilterLink *link);
578 * Set the closed field of a link.
579 * @deprecated applications are not supposed to mess with links, they should
583 void avfilter_link_set_closed(AVFilterLink *link, int closed);
586 * Negotiate the media format, dimensions, etc of all inputs to a filter.
588 * @param filter the filter to negotiate the properties for its inputs
589 * @return zero on successful negotiation
591 int avfilter_config_links(AVFilterContext *filter);
593 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
594 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
597 * Make the filter instance process a command.
598 * It is recommended to use avfilter_graph_send_command().
600 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
602 /** Initialize the filter system. Register all builtin filters. */
603 void avfilter_register_all(void);
605 #if FF_API_OLD_FILTER_REGISTER
606 /** Uninitialize the filter system. Unregister all filters. */
608 void avfilter_uninit(void);
612 * Register a filter. This is only needed if you plan to use
613 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
614 * filter can still by instantiated with avfilter_graph_alloc_filter even if it
617 * @param filter the filter to register
618 * @return 0 if the registration was successful, a negative value
621 int avfilter_register(AVFilter *filter);
624 * Get a filter definition matching the given name.
626 * @param name the filter name to find
627 * @return the filter definition, if any matching one is registered.
628 * NULL if none found.
630 #if !FF_API_NOCONST_GET_NAME
633 AVFilter *avfilter_get_by_name(const char *name);
636 * Iterate over all registered filters.
637 * @return If prev is non-NULL, next registered filter after prev or NULL if
638 * prev is the last filter. If prev is NULL, return the first registered filter.
640 const AVFilter *avfilter_next(const AVFilter *prev);
642 #if FF_API_OLD_FILTER_REGISTER
644 * If filter is NULL, returns a pointer to the first registered filter pointer,
645 * if filter is non-NULL, returns the next pointer after filter.
646 * If the returned pointer points to NULL, the last registered filter
647 * was already reached.
648 * @deprecated use avfilter_next()
651 AVFilter **av_filter_next(AVFilter **filter);
654 #if FF_API_AVFILTER_OPEN
656 * Create a filter instance.
658 * @param filter_ctx put here a pointer to the created filter context
659 * on success, NULL on failure
660 * @param filter the filter to create an instance of
661 * @param inst_name Name to give to the new instance. Can be NULL for none.
662 * @return >= 0 in case of success, a negative error code otherwise
663 * @deprecated use avfilter_graph_alloc_filter() instead
666 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
670 #if FF_API_AVFILTER_INIT_FILTER
672 * Initialize a filter.
674 * @param filter the filter to initialize
675 * @param args A string of parameters to use when initializing the filter.
676 * The format and meaning of this string varies by filter.
677 * @param opaque Any extra non-string data needed by the filter. The meaning
678 * of this parameter varies by filter.
679 * @return zero on success
682 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
686 * Initialize a filter with the supplied parameters.
688 * @param ctx uninitialized filter context to initialize
689 * @param args Options to initialize the filter with. This must be a
690 * ':'-separated list of options in the 'key=value' form.
691 * May be NULL if the options have been set directly using the
692 * AVOptions API or there are no options that need to be set.
693 * @return 0 on success, a negative AVERROR on failure
695 int avfilter_init_str(AVFilterContext *ctx, const char *args);
698 * Initialize a filter with the supplied dictionary of options.
700 * @param ctx uninitialized filter context to initialize
701 * @param options An AVDictionary filled with options for this filter. On
702 * return this parameter will be destroyed and replaced with
703 * a dict containing options that were not found. This dictionary
704 * must be freed by the caller.
705 * May be NULL, then this function is equivalent to
706 * avfilter_init_str() with the second parameter set to NULL.
707 * @return 0 on success, a negative AVERROR on failure
709 * @note This function and avfilter_init_str() do essentially the same thing,
710 * the difference is in manner in which the options are passed. It is up to the
711 * calling code to choose whichever is more preferable. The two functions also
712 * behave differently when some of the provided options are not declared as
713 * supported by the filter. In such a case, avfilter_init_str() will fail, but
714 * this function will leave those extra options in the options AVDictionary and
717 int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options);
720 * Free a filter context. This will also remove the filter from its
721 * filtergraph's list of filters.
723 * @param filter the filter to free
725 void avfilter_free(AVFilterContext *filter);
728 * Insert a filter in the middle of an existing link.
730 * @param link the link into which the filter should be inserted
731 * @param filt the filter to be inserted
732 * @param filt_srcpad_idx the input pad on the filter to connect
733 * @param filt_dstpad_idx the output pad on the filter to connect
734 * @return zero on success
736 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
737 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
740 * @return AVClass for AVFilterContext.
742 * @see av_opt_find().
744 const AVClass *avfilter_get_class(void);
746 typedef struct AVFilterGraphInternal AVFilterGraphInternal;
749 * A function pointer passed to the @ref AVFilterGraph.execute callback to be
750 * executed multiple times, possibly in parallel.
752 * @param ctx the filter context the job belongs to
753 * @param arg an opaque parameter passed through from @ref
754 * AVFilterGraph.execute
755 * @param jobnr the index of the job being executed
756 * @param nb_jobs the total number of jobs
758 * @return 0 on success, a negative AVERROR on error
760 typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
763 * A function executing multiple jobs, possibly in parallel.
765 * @param ctx the filter context to which the jobs belong
766 * @param func the function to be called multiple times
767 * @param arg the argument to be passed to func
768 * @param ret a nb_jobs-sized array to be filled with return values from each
770 * @param nb_jobs the number of jobs to execute
772 * @return 0 on success, a negative AVERROR on error
774 typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
775 void *arg, int *ret, int nb_jobs);
777 typedef struct AVFilterGraph {
778 const AVClass *av_class;
779 AVFilterContext **filters;
782 char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
783 char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
786 * Type of multithreading allowed for filters in this graph. A combination
787 * of AVFILTER_THREAD_* flags.
789 * May be set by the caller at any point, the setting will apply to all
790 * filters initialized after that. The default is allowing everything.
792 * When a filter in this graph is initialized, this field is combined using
793 * bit AND with AVFilterContext.thread_type to get the final mask used for
794 * determining allowed threading types. I.e. a threading type needs to be
795 * set in both to be allowed.
800 * Maximum number of threads used by filters in this graph. May be set by
801 * the caller before adding any filters to the filtergraph. Zero (the
802 * default) means that the number of threads is determined automatically.
807 * Opaque object for libavfilter internal use.
809 AVFilterGraphInternal *internal;
812 * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
813 * be used from callbacks like @ref AVFilterGraph.execute.
814 * Libavfilter will not touch this field in any way.
819 * This callback may be set by the caller immediately after allocating the
820 * graph and before adding any filters to it, to provide a custom
821 * multithreading implementation.
823 * If set, filters with slice threading capability will call this callback
824 * to execute multiple jobs in parallel.
826 * If this field is left unset, libavfilter will use its internal
827 * implementation, which may or may not be multithreaded depending on the
828 * platform and build options.
830 avfilter_execute_func *execute;
832 char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
837 * The following fields are for internal use only.
838 * Their type, offset, number and semantic can change without notice.
841 AVFilterLink **sink_links;
842 int sink_links_count;
844 unsigned disable_auto_convert;
848 * Allocate a filter graph.
850 * @return the allocated filter graph on success or NULL.
852 AVFilterGraph *avfilter_graph_alloc(void);
855 * Create a new filter instance in a filter graph.
857 * @param graph graph in which the new filter will be used
858 * @param filter the filter to create an instance of
859 * @param name Name to give to the new instance (will be copied to
860 * AVFilterContext.name). This may be used by the caller to identify
861 * different filters, libavfilter itself assigns no semantics to
862 * this parameter. May be NULL.
864 * @return the context of the newly created filter instance (note that it is
865 * also retrievable directly through AVFilterGraph.filters or with
866 * avfilter_graph_get_filter()) on success or NULL on failure.
868 AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
869 const AVFilter *filter,
873 * Get a filter instance identified by instance name from graph.
875 * @param graph filter graph to search through.
876 * @param name filter instance name (should be unique in the graph).
877 * @return the pointer to the found filter instance or NULL if it
880 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, const char *name);
882 #if FF_API_AVFILTER_OPEN
884 * Add an existing filter instance to a filter graph.
886 * @param graphctx the filter graph
887 * @param filter the filter to be added
889 * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a
893 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
897 * Create and add a filter instance into an existing graph.
898 * The filter instance is created from the filter filt and inited
899 * with the parameters args and opaque.
901 * In case of success put in *filt_ctx the pointer to the created
902 * filter instance, otherwise set *filt_ctx to NULL.
904 * @param name the instance name to give to the created filter instance
905 * @param graph_ctx the filter graph
906 * @return a negative AVERROR error code in case of failure, a non
907 * negative value otherwise
909 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
910 const char *name, const char *args, void *opaque,
911 AVFilterGraph *graph_ctx);
914 * Enable or disable automatic format conversion inside the graph.
916 * Note that format conversion can still happen inside explicitly inserted
917 * scale and aresample filters.
919 * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
921 void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags);
924 AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
925 AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
929 * Check validity and configure all the links and formats in the graph.
931 * @param graphctx the filter graph
932 * @param log_ctx context used for logging
933 * @return >= 0 in case of success, a negative AVERROR code otherwise
935 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
938 * Free a graph, destroy its links, and set *graph to NULL.
939 * If *graph is NULL, do nothing.
941 void avfilter_graph_free(AVFilterGraph **graph);
944 * A linked-list of the inputs/outputs of the filter chain.
946 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
947 * where it is used to communicate open (unlinked) inputs and outputs from and
949 * This struct specifies, per each not connected pad contained in the graph, the
950 * filter context and the pad index required for establishing a link.
952 typedef struct AVFilterInOut {
953 /** unique name for this input/output in the list */
956 /** filter context associated to this input/output */
957 AVFilterContext *filter_ctx;
959 /** index of the filt_ctx pad to use for linking */
962 /** next input/input in the list, NULL if this is the last */
963 struct AVFilterInOut *next;
967 * Allocate a single AVFilterInOut entry.
968 * Must be freed with avfilter_inout_free().
969 * @return allocated AVFilterInOut on success, NULL on failure.
971 AVFilterInOut *avfilter_inout_alloc(void);
974 * Free the supplied list of AVFilterInOut and set *inout to NULL.
975 * If *inout is NULL, do nothing.
977 void avfilter_inout_free(AVFilterInOut **inout);
980 * Add a graph described by a string to a graph.
982 * @note The caller must provide the lists of inputs and outputs,
983 * which therefore must be known before calling the function.
985 * @note The inputs parameter describes inputs of the already existing
986 * part of the graph; i.e. from the point of view of the newly created
987 * part, they are outputs. Similarly the outputs parameter describes
988 * outputs of the already existing filters, which are provided as
989 * inputs to the parsed filters.
991 * @param graph the filter graph where to link the parsed graph context
992 * @param filters string to be parsed
993 * @param inputs linked list to the inputs of the graph
994 * @param outputs linked list to the outputs of the graph
995 * @return zero on success, a negative AVERROR code on error
997 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
998 AVFilterInOut *inputs, AVFilterInOut *outputs,
1002 * Add a graph described by a string to a graph.
1004 * In the graph filters description, if the input label of the first
1005 * filter is not specified, "in" is assumed; if the output label of
1006 * the last filter is not specified, "out" is assumed.
1008 * @param graph the filter graph where to link the parsed graph context
1009 * @param filters string to be parsed
1010 * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
1011 * If non-NULL, *inputs is updated to contain the list of open inputs
1012 * after the parsing, should be freed with avfilter_inout_free().
1013 * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
1014 * If non-NULL, *outputs is updated to contain the list of open outputs
1015 * after the parsing, should be freed with avfilter_inout_free().
1016 * @return non negative on success, a negative AVERROR code on error
1018 int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters,
1019 AVFilterInOut **inputs, AVFilterInOut **outputs,
1023 * Add a graph described by a string to a graph.
1025 * @param[in] graph the filter graph where to link the parsed graph context
1026 * @param[in] filters string to be parsed
1027 * @param[out] inputs a linked list of all free (unlinked) inputs of the
1028 * parsed graph will be returned here. It is to be freed
1029 * by the caller using avfilter_inout_free().
1030 * @param[out] outputs a linked list of all free (unlinked) outputs of the
1031 * parsed graph will be returned here. It is to be freed by the
1032 * caller using avfilter_inout_free().
1033 * @return zero on success, a negative AVERROR code on error
1035 * @note This function returns the inputs and outputs that are left
1036 * unlinked after parsing the graph and the caller then deals with
1038 * @note This function makes no reference whatsoever to already
1039 * existing parts of the graph and the inputs parameter will on return
1040 * contain inputs of the newly parsed part of the graph. Analogously
1041 * the outputs parameter will contain outputs of the newly created
1044 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
1045 AVFilterInOut **inputs,
1046 AVFilterInOut **outputs);
1049 * Send a command to one or more filter instances.
1051 * @param graph the filter graph
1052 * @param target the filter(s) to which the command should be sent
1053 * "all" sends to all filters
1054 * otherwise it can be a filter or filter instance name
1055 * which will send the command to all matching filters.
1056 * @param cmd the command to send, for handling simplicity all commands must be alphanumeric only
1057 * @param arg the argument for the command
1058 * @param res a buffer with size res_size where the filter(s) can return a response.
1060 * @returns >=0 on success otherwise an error code.
1061 * AVERROR(ENOSYS) on unsupported commands
1063 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
1066 * Queue a command for one or more filter instances.
1068 * @param graph the filter graph
1069 * @param target the filter(s) to which the command should be sent
1070 * "all" sends to all filters
1071 * otherwise it can be a filter or filter instance name
1072 * which will send the command to all matching filters.
1073 * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
1074 * @param arg the argument for the command
1075 * @param ts time at which the command should be sent to the filter
1077 * @note As this executes commands after this function returns, no return code
1078 * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
1080 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
1084 * Dump a graph into a human-readable string representation.
1086 * @param graph the graph to dump
1087 * @param options formatting options; currently ignored
1088 * @return a string, or NULL in case of memory allocation failure;
1089 * the string must be freed using av_free
1091 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
1094 * Request a frame on the oldest sink link.
1096 * If the request returns AVERROR_EOF, try the next.
1098 * Note that this function is not meant to be the sole scheduling mechanism
1099 * of a filtergraph, only a convenience function to help drain a filtergraph
1100 * in a balanced way under normal circumstances.
1102 * Also note that AVERROR_EOF does not mean that frames did not arrive on
1103 * some of the sinks during the process.
1104 * When there are multiple sink links, in case the requested link
1105 * returns an EOF, this may cause a filter to flush pending frames
1106 * which are sent to another sink link, although unrequested.
1108 * @return the return value of ff_request_frame(),
1109 * or AVERROR_EOF if all links returned AVERROR_EOF
1111 int avfilter_graph_request_oldest(AVFilterGraph *graph);
1117 #endif /* AVFILTER_AVFILTER_H */