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
33 * Graph-based frame editing library.
40 #include "libavutil/attributes.h"
41 #include "libavutil/avutil.h"
42 #include "libavutil/buffer.h"
43 #include "libavutil/dict.h"
44 #include "libavutil/frame.h"
45 #include "libavutil/log.h"
46 #include "libavutil/samplefmt.h"
47 #include "libavutil/pixfmt.h"
48 #include "libavutil/rational.h"
50 #include "libavfilter/version.h"
53 * Return the LIBAVFILTER_VERSION_INT constant.
55 unsigned avfilter_version(void);
58 * Return the libavfilter build-time configuration.
60 const char *avfilter_configuration(void);
63 * Return the libavfilter license.
65 const char *avfilter_license(void);
67 typedef struct AVFilterContext AVFilterContext;
68 typedef struct AVFilterLink AVFilterLink;
69 typedef struct AVFilterPad AVFilterPad;
70 typedef struct AVFilterFormats AVFilterFormats;
71 typedef struct AVFilterChannelLayouts AVFilterChannelLayouts;
74 * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
75 * AVFilter.inputs/outputs).
77 int avfilter_pad_count(const AVFilterPad *pads);
80 * Get the name of an AVFilterPad.
82 * @param pads an array of AVFilterPads
83 * @param pad_idx index of the pad in the array; it is the caller's
84 * responsibility to ensure the index is valid
86 * @return name of the pad_idx'th pad in pads
88 const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
91 * Get the type of an AVFilterPad.
93 * @param pads an array of AVFilterPads
94 * @param pad_idx index of the pad in the array; it is the caller's
95 * responsibility to ensure the index is valid
97 * @return type of the pad_idx'th pad in pads
99 enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
102 * The number of the filter inputs is not determined just by AVFilter.inputs.
103 * The filter might add additional inputs during initialization depending on the
104 * options supplied to it.
106 #define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
108 * The number of the filter outputs is not determined just by AVFilter.outputs.
109 * The filter might add additional outputs during initialization depending on
110 * the options supplied to it.
112 #define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
114 * The filter supports multithreading by splitting frames into multiple parts
115 * and processing them concurrently.
117 #define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
119 * Some filters support a generic "enable" expression option that can be used
120 * to enable or disable a filter in the timeline. Filters supporting this
121 * option have this flag set. When the enable expression is false, the default
122 * no-op filter_frame() function is called in place of the filter_frame()
123 * callback defined on each input pad, thus the frame is passed unchanged to
126 #define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16)
128 * Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will
129 * have its filter_frame() callback(s) called as usual even when the enable
130 * expression is false. The filter will disable filtering within the
131 * filter_frame() callback(s) itself, for example executing code depending on
132 * the AVFilterContext->is_disabled value.
134 #define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)
136 * Handy mask to test whether the filter supports or no the timeline feature
137 * (internally or generically).
139 #define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)
142 * Filter definition. This defines the pads a filter contains, and all the
143 * callback functions used to interact with the filter.
145 typedef struct AVFilter {
147 * Filter name. Must be non-NULL and unique among filters.
152 * A description of the filter. May be NULL.
154 * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
156 const char *description;
159 * List of inputs, terminated by a zeroed element.
161 * NULL if there are no (static) inputs. Instances of filters with
162 * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in
165 const AVFilterPad *inputs;
167 * List of outputs, terminated by a zeroed element.
169 * NULL if there are no (static) outputs. Instances of filters with
170 * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in
173 const AVFilterPad *outputs;
176 * A class for the private data, used to declare filter private AVOptions.
177 * This field is NULL for filters that do not declare any options.
179 * If this field is non-NULL, the first member of the filter private data
180 * must be a pointer to AVClass, which will be set by libavfilter generic
181 * code to this class.
183 const AVClass *priv_class;
186 * A combination of AVFILTER_FLAG_*
190 /*****************************************************************
191 * All fields below this line are not part of the public API. They
192 * may not be used outside of libavfilter and can be changed and
194 * New public fields should be added right above.
195 *****************************************************************
199 * Filter pre-initialization function
201 * This callback will be called immediately after the filter context is
202 * allocated, to allow allocating and initing sub-objects.
204 * If this callback is not NULL, the uninit callback will be called on
205 * allocation failure.
207 * @return 0 on success,
208 * AVERROR code on failure (but the code will be
209 * dropped and treated as ENOMEM by the calling code)
211 int (*preinit)(AVFilterContext *ctx);
214 * Filter initialization function.
216 * This callback will be called only once during the filter lifetime, after
217 * all the options have been set, but before links between filters are
218 * established and format negotiation is done.
220 * Basic filter initialization should be done here. Filters with dynamic
221 * inputs and/or outputs should create those inputs/outputs here based on
222 * provided options. No more changes to this filter's inputs/outputs can be
223 * done after this callback.
225 * This callback must not assume that the filter links exist or frame
226 * parameters are known.
228 * @ref AVFilter.uninit "uninit" is guaranteed to be called even if
229 * initialization fails, so this callback does not have to clean up on
232 * @return 0 on success, a negative AVERROR on failure
234 int (*init)(AVFilterContext *ctx);
237 * Should be set instead of @ref AVFilter.init "init" by the filters that
238 * want to pass a dictionary of AVOptions to nested contexts that are
239 * allocated during init.
241 * On return, the options dict should be freed and replaced with one that
242 * contains all the options which could not be processed by this filter (or
243 * with NULL if all the options were processed).
245 * Otherwise the semantics is the same as for @ref AVFilter.init "init".
247 int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
250 * Filter uninitialization function.
252 * Called only once right before the filter is freed. Should deallocate any
253 * memory held by the filter, release any buffer references, etc. It does
254 * not need to deallocate the AVFilterContext.priv memory itself.
256 * This callback may be called even if @ref AVFilter.init "init" was not
257 * called or failed, so it must be prepared to handle such a situation.
259 void (*uninit)(AVFilterContext *ctx);
262 * Query formats supported by the filter on its inputs and outputs.
264 * This callback is called after the filter is initialized (so the inputs
265 * and outputs are fixed), shortly before the format negotiation. This
266 * callback may be called more than once.
268 * This callback must set AVFilterLink.outcfg.formats on every input link and
269 * AVFilterLink.incfg.formats on every output link to a list of pixel/sample
270 * formats that the filter supports on that link. For audio links, this
271 * filter must also set @ref AVFilterLink.incfg.samplerates "in_samplerates" /
272 * @ref AVFilterLink.outcfg.samplerates "out_samplerates" and
273 * @ref AVFilterLink.incfg.channel_layouts "in_channel_layouts" /
274 * @ref AVFilterLink.outcfg.channel_layouts "out_channel_layouts" analogously.
276 * This callback may be NULL for filters with one input, in which case
277 * libavfilter assumes that it supports all input formats and preserves
280 * @return zero on success, a negative value corresponding to an
281 * AVERROR code otherwise
283 int (*query_formats)(AVFilterContext *);
285 int priv_size; ///< size of private data to allocate for the filter
287 int flags_internal; ///< Additional flags for avfilter internal use only.
290 * Make the filter instance process a command.
292 * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
293 * @param arg the argument for the command
294 * @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.
295 * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
296 * time consuming then a filter should treat it like an unsupported command
298 * @returns >=0 on success otherwise an error code.
299 * AVERROR(ENOSYS) on unsupported commands
301 int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
304 * Filter initialization function, alternative to the init()
305 * callback. Args contains the user-supplied parameters, opaque is
306 * used for providing binary data.
308 int (*init_opaque)(AVFilterContext *ctx, void *opaque);
311 * Filter activation function.
313 * Called when any processing is needed from the filter, instead of any
314 * filter_frame and request_frame on pads.
316 * The function must examine inlinks and outlinks and perform a single
317 * step of processing. If there is nothing to do, the function must do
318 * nothing and not return an error. If more steps are or may be
319 * possible, it must use ff_filter_set_ready() to schedule another
322 int (*activate)(AVFilterContext *ctx);
326 * Process multiple parts of the frame concurrently.
328 #define AVFILTER_THREAD_SLICE (1 << 0)
330 typedef struct AVFilterInternal AVFilterInternal;
332 /** An instance of a filter */
333 struct AVFilterContext {
334 const AVClass *av_class; ///< needed for av_log() and filters common options
336 const AVFilter *filter; ///< the AVFilter of which this is an instance
338 char *name; ///< name of this filter instance
340 AVFilterPad *input_pads; ///< array of input pads
341 AVFilterLink **inputs; ///< array of pointers to input links
342 unsigned nb_inputs; ///< number of input pads
344 AVFilterPad *output_pads; ///< array of output pads
345 AVFilterLink **outputs; ///< array of pointers to output links
346 unsigned nb_outputs; ///< number of output pads
348 void *priv; ///< private data for use by the filter
350 struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
353 * Type of multithreading being allowed/used. A combination of
354 * AVFILTER_THREAD_* flags.
356 * May be set by the caller before initializing the filter to forbid some
357 * or all kinds of multithreading for this filter. The default is allowing
360 * When the filter is initialized, this field is combined using bit AND with
361 * AVFilterGraph.thread_type to get the final mask used for determining
362 * allowed threading types. I.e. a threading type needs to be set in both
365 * After the filter is initialized, libavfilter sets this field to the
366 * threading type that is actually used (0 for no multithreading).
371 * An opaque struct for libavfilter internal use.
373 AVFilterInternal *internal;
375 struct AVFilterCommand *command_queue;
377 char *enable_str; ///< enable expression string
378 void *enable; ///< parsed expression (AVExpr*)
379 double *var_values; ///< variable values for the enable expression
380 int is_disabled; ///< the enabled state from the last expression evaluation
383 * For filters which will create hardware frames, sets the device the
384 * filter should create them in. All other filters will ignore this field:
385 * in particular, a filter which consumes or processes hardware frames will
386 * instead use the hw_frames_ctx field in AVFilterLink to carry the
387 * hardware context information.
389 AVBufferRef *hw_device_ctx;
392 * Max number of threads allowed in this filter instance.
393 * If <= 0, its value is ignored.
394 * Overrides global number of threads set per filter graph.
399 * Ready status of the filter.
400 * A non-0 value means that the filter needs activating;
401 * a higher value suggests a more urgent activation.
406 * Sets the number of extra hardware frames which the filter will
407 * allocate on its output links for use in following filters or by
410 * Some hardware filters require all frames that they will use for
411 * output to be defined in advance before filtering starts. For such
412 * filters, any hardware frame pools used for output must therefore be
413 * of fixed size. The extra frames set here are on top of any number
414 * that the filter needs internally in order to operate normally.
416 * This field must be set before the graph containing this filter is
423 * Lists of formats / etc. supported by an end of a link.
425 * This structure is directly part of AVFilterLink, in two copies:
426 * one for the source filter, one for the destination filter.
428 * These lists are used for negotiating the format to actually be used,
429 * which will be loaded into the format and channel_layout members of
430 * AVFilterLink, when chosen.
432 typedef struct AVFilterFormatsConfig {
435 * List of supported formats (pixel or sample).
437 AVFilterFormats *formats;
440 * Lists of supported sample rates, only for audio.
442 AVFilterFormats *samplerates;
445 * Lists of supported channel layouts, only for audio.
447 AVFilterChannelLayouts *channel_layouts;
449 } AVFilterFormatsConfig;
452 * A link between two filters. This contains pointers to the source and
453 * destination filters between which this link exists, and the indexes of
454 * the pads involved. In addition, this link also contains the parameters
455 * which have been negotiated and agreed upon between the filter, such as
456 * image dimensions, format, etc.
458 * Applications must not normally access the link structure directly.
459 * Use the buffersrc and buffersink API instead.
460 * In the future, access to the header may be reserved for filters
463 struct AVFilterLink {
464 AVFilterContext *src; ///< source filter
465 AVFilterPad *srcpad; ///< output pad on the source filter
467 AVFilterContext *dst; ///< dest filter
468 AVFilterPad *dstpad; ///< input pad on the dest filter
470 enum AVMediaType type; ///< filter media type
472 /* These parameters apply only to video */
473 int w; ///< agreed upon image width
474 int h; ///< agreed upon image height
475 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
476 /* These parameters apply only to audio */
477 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
478 int sample_rate; ///< samples per second
480 int format; ///< agreed upon media format
483 * Define the time base used by the PTS of the frames/samples
484 * which will pass through this link.
485 * During the configuration stage, each filter is supposed to
486 * change only the output timebase, while the timebase of the
487 * input link is assumed to be an unchangeable property.
489 AVRational time_base;
491 /*****************************************************************
492 * All fields below this line are not part of the public API. They
493 * may not be used outside of libavfilter and can be changed and
495 * New public fields should be added right above.
496 *****************************************************************
500 * Lists of supported formats / etc. supported by the input filter.
502 AVFilterFormatsConfig incfg;
505 * Lists of supported formats / etc. supported by the output filter.
507 AVFilterFormatsConfig outcfg;
509 /** stage of the initialization of the link properties (dimensions, etc) */
511 AVLINK_UNINIT = 0, ///< not started
512 AVLINK_STARTINIT, ///< started, but incomplete
513 AVLINK_INIT ///< complete
517 * Graph the filter belongs to.
519 struct AVFilterGraph *graph;
522 * Current timestamp of the link, as defined by the most recent
523 * frame(s), in link time_base units.
528 * Current timestamp of the link, as defined by the most recent
529 * frame(s), in AV_TIME_BASE units.
531 int64_t current_pts_us;
534 * Index in the age array.
539 * Frame rate of the stream on the link, or 1/0 if unknown or variable;
540 * if left to 0/0, will be automatically copied from the first input
541 * of the source filter if it exists.
543 * Sources should set it to the best estimation of the real frame rate.
544 * If the source frame rate is unknown or variable, set this to 1/0.
545 * Filters should update it if necessary depending on their function.
546 * Sinks can use it to set a default output frame rate.
547 * It is similar to the r_frame_rate field in AVStream.
549 AVRational frame_rate;
552 * Buffer partially filled with samples to achieve a fixed/minimum size.
554 AVFrame *partial_buf;
557 * Size of the partial buffer to allocate.
558 * Must be between min_samples and max_samples.
560 int partial_buf_size;
563 * Minimum number of samples to filter at once. If filter_frame() is
564 * called with fewer samples, it will accumulate them in partial_buf.
565 * This field and the related ones must not be changed after filtering
567 * If 0, all related fields are ignored.
572 * Maximum number of samples to filter at once. If filter_frame() is
573 * called with more samples, it will split them.
578 * Number of channels.
583 * Number of past frames sent through the link.
585 int64_t frame_count_in, frame_count_out;
588 * A pointer to a FFFramePool struct.
593 * True if a frame is currently wanted on the output of this filter.
594 * Set when ff_request_frame() is called by the output,
595 * cleared when a frame is filtered.
597 int frame_wanted_out;
600 * For hwaccel pixel formats, this should be a reference to the
601 * AVHWFramesContext describing the frames.
603 AVBufferRef *hw_frames_ctx;
605 #ifndef FF_INTERNAL_FIELDS
608 * Internal structure members.
609 * The fields below this limit are internal for libavfilter's use
610 * and must in no way be accessed by applications.
612 char reserved[0xF000];
614 #else /* FF_INTERNAL_FIELDS */
617 * Queue of frames waiting to be filtered.
622 * If set, the source filter can not generate a frame as is.
623 * The goal is to avoid repeatedly calling the request_frame() method on
626 int frame_blocked_in;
630 * If not zero, all attempts of filter_frame will fail with the
631 * corresponding code.
636 * Timestamp of the input status change.
638 int64_t status_in_pts;
641 * Link output status.
642 * If not zero, all attempts of request_frame will fail with the
643 * corresponding code.
647 #endif /* FF_INTERNAL_FIELDS */
652 * Link two filters together.
654 * @param src the source filter
655 * @param srcpad index of the output pad on the source filter
656 * @param dst the destination filter
657 * @param dstpad index of the input pad on the destination filter
658 * @return zero on success
660 int avfilter_link(AVFilterContext *src, unsigned srcpad,
661 AVFilterContext *dst, unsigned dstpad);
664 * Free the link in *link, and set its pointer to NULL.
666 void avfilter_link_free(AVFilterLink **link);
668 #if FF_API_FILTER_LINK_SET_CLOSED
670 * Set the closed field of a link.
671 * @deprecated applications are not supposed to mess with links, they should
675 void avfilter_link_set_closed(AVFilterLink *link, int closed);
678 * Negotiate the media format, dimensions, etc of all inputs to a filter.
680 * @param filter the filter to negotiate the properties for its inputs
681 * @return zero on successful negotiation
683 int avfilter_config_links(AVFilterContext *filter);
685 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
686 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
689 * Make the filter instance process a command.
690 * It is recommended to use avfilter_graph_send_command().
692 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
695 * Iterate over all registered filters.
697 * @param opaque a pointer where libavfilter will store the iteration state. Must
698 * point to NULL to start the iteration.
700 * @return the next registered filter or NULL when the iteration is
703 const AVFilter *av_filter_iterate(void **opaque);
706 * Get a filter definition matching the given name.
708 * @param name the filter name to find
709 * @return the filter definition, if any matching one is registered.
710 * NULL if none found.
712 const AVFilter *avfilter_get_by_name(const char *name);
716 * Initialize a filter with the supplied parameters.
718 * @param ctx uninitialized filter context to initialize
719 * @param args Options to initialize the filter with. This must be a
720 * ':'-separated list of options in the 'key=value' form.
721 * May be NULL if the options have been set directly using the
722 * AVOptions API or there are no options that need to be set.
723 * @return 0 on success, a negative AVERROR on failure
725 int avfilter_init_str(AVFilterContext *ctx, const char *args);
728 * Initialize a filter with the supplied dictionary of options.
730 * @param ctx uninitialized filter context to initialize
731 * @param options An AVDictionary filled with options for this filter. On
732 * return this parameter will be destroyed and replaced with
733 * a dict containing options that were not found. This dictionary
734 * must be freed by the caller.
735 * May be NULL, then this function is equivalent to
736 * avfilter_init_str() with the second parameter set to NULL.
737 * @return 0 on success, a negative AVERROR on failure
739 * @note This function and avfilter_init_str() do essentially the same thing,
740 * the difference is in manner in which the options are passed. It is up to the
741 * calling code to choose whichever is more preferable. The two functions also
742 * behave differently when some of the provided options are not declared as
743 * supported by the filter. In such a case, avfilter_init_str() will fail, but
744 * this function will leave those extra options in the options AVDictionary and
747 int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options);
750 * Free a filter context. This will also remove the filter from its
751 * filtergraph's list of filters.
753 * @param filter the filter to free
755 void avfilter_free(AVFilterContext *filter);
758 * Insert a filter in the middle of an existing link.
760 * @param link the link into which the filter should be inserted
761 * @param filt the filter to be inserted
762 * @param filt_srcpad_idx the input pad on the filter to connect
763 * @param filt_dstpad_idx the output pad on the filter to connect
764 * @return zero on success
766 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
767 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
770 * @return AVClass for AVFilterContext.
772 * @see av_opt_find().
774 const AVClass *avfilter_get_class(void);
776 typedef struct AVFilterGraphInternal AVFilterGraphInternal;
779 * A function pointer passed to the @ref AVFilterGraph.execute callback to be
780 * executed multiple times, possibly in parallel.
782 * @param ctx the filter context the job belongs to
783 * @param arg an opaque parameter passed through from @ref
784 * AVFilterGraph.execute
785 * @param jobnr the index of the job being executed
786 * @param nb_jobs the total number of jobs
788 * @return 0 on success, a negative AVERROR on error
790 typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
793 * A function executing multiple jobs, possibly in parallel.
795 * @param ctx the filter context to which the jobs belong
796 * @param func the function to be called multiple times
797 * @param arg the argument to be passed to func
798 * @param ret a nb_jobs-sized array to be filled with return values from each
800 * @param nb_jobs the number of jobs to execute
802 * @return 0 on success, a negative AVERROR on error
804 typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
805 void *arg, int *ret, int nb_jobs);
807 typedef struct AVFilterGraph {
808 const AVClass *av_class;
809 AVFilterContext **filters;
812 char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
815 * Type of multithreading allowed for filters in this graph. A combination
816 * of AVFILTER_THREAD_* flags.
818 * May be set by the caller at any point, the setting will apply to all
819 * filters initialized after that. The default is allowing everything.
821 * When a filter in this graph is initialized, this field is combined using
822 * bit AND with AVFilterContext.thread_type to get the final mask used for
823 * determining allowed threading types. I.e. a threading type needs to be
824 * set in both to be allowed.
829 * Maximum number of threads used by filters in this graph. May be set by
830 * the caller before adding any filters to the filtergraph. Zero (the
831 * default) means that the number of threads is determined automatically.
836 * Opaque object for libavfilter internal use.
838 AVFilterGraphInternal *internal;
841 * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
842 * be used from callbacks like @ref AVFilterGraph.execute.
843 * Libavfilter will not touch this field in any way.
848 * This callback may be set by the caller immediately after allocating the
849 * graph and before adding any filters to it, to provide a custom
850 * multithreading implementation.
852 * If set, filters with slice threading capability will call this callback
853 * to execute multiple jobs in parallel.
855 * If this field is left unset, libavfilter will use its internal
856 * implementation, which may or may not be multithreaded depending on the
857 * platform and build options.
859 avfilter_execute_func *execute;
861 char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
866 * The following fields are for internal use only.
867 * Their type, offset, number and semantic can change without notice.
870 AVFilterLink **sink_links;
871 int sink_links_count;
873 unsigned disable_auto_convert;
877 * Allocate a filter graph.
879 * @return the allocated filter graph on success or NULL.
881 AVFilterGraph *avfilter_graph_alloc(void);
884 * Create a new filter instance in a filter graph.
886 * @param graph graph in which the new filter will be used
887 * @param filter the filter to create an instance of
888 * @param name Name to give to the new instance (will be copied to
889 * AVFilterContext.name). This may be used by the caller to identify
890 * different filters, libavfilter itself assigns no semantics to
891 * this parameter. May be NULL.
893 * @return the context of the newly created filter instance (note that it is
894 * also retrievable directly through AVFilterGraph.filters or with
895 * avfilter_graph_get_filter()) on success or NULL on failure.
897 AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
898 const AVFilter *filter,
902 * Get a filter instance identified by instance name from graph.
904 * @param graph filter graph to search through.
905 * @param name filter instance name (should be unique in the graph).
906 * @return the pointer to the found filter instance or NULL if it
909 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, const char *name);
912 * Create and add a filter instance into an existing graph.
913 * The filter instance is created from the filter filt and inited
914 * with the parameter args. opaque is currently ignored.
916 * In case of success put in *filt_ctx the pointer to the created
917 * filter instance, otherwise set *filt_ctx to NULL.
919 * @param name the instance name to give to the created filter instance
920 * @param graph_ctx the filter graph
921 * @return a negative AVERROR error code in case of failure, a non
922 * negative value otherwise
924 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
925 const char *name, const char *args, void *opaque,
926 AVFilterGraph *graph_ctx);
929 * Enable or disable automatic format conversion inside the graph.
931 * Note that format conversion can still happen inside explicitly inserted
932 * scale and aresample filters.
934 * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
936 void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags);
939 AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
940 AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
944 * Check validity and configure all the links and formats in the graph.
946 * @param graphctx the filter graph
947 * @param log_ctx context used for logging
948 * @return >= 0 in case of success, a negative AVERROR code otherwise
950 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
953 * Free a graph, destroy its links, and set *graph to NULL.
954 * If *graph is NULL, do nothing.
956 void avfilter_graph_free(AVFilterGraph **graph);
959 * A linked-list of the inputs/outputs of the filter chain.
961 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
962 * where it is used to communicate open (unlinked) inputs and outputs from and
964 * This struct specifies, per each not connected pad contained in the graph, the
965 * filter context and the pad index required for establishing a link.
967 typedef struct AVFilterInOut {
968 /** unique name for this input/output in the list */
971 /** filter context associated to this input/output */
972 AVFilterContext *filter_ctx;
974 /** index of the filt_ctx pad to use for linking */
977 /** next input/input in the list, NULL if this is the last */
978 struct AVFilterInOut *next;
982 * Allocate a single AVFilterInOut entry.
983 * Must be freed with avfilter_inout_free().
984 * @return allocated AVFilterInOut on success, NULL on failure.
986 AVFilterInOut *avfilter_inout_alloc(void);
989 * Free the supplied list of AVFilterInOut and set *inout to NULL.
990 * If *inout is NULL, do nothing.
992 void avfilter_inout_free(AVFilterInOut **inout);
995 * Add a graph described by a string to a graph.
997 * @note The caller must provide the lists of inputs and outputs,
998 * which therefore must be known before calling the function.
1000 * @note The inputs parameter describes inputs of the already existing
1001 * part of the graph; i.e. from the point of view of the newly created
1002 * part, they are outputs. Similarly the outputs parameter describes
1003 * outputs of the already existing filters, which are provided as
1004 * inputs to the parsed filters.
1006 * @param graph the filter graph where to link the parsed graph context
1007 * @param filters string to be parsed
1008 * @param inputs linked list to the inputs of the graph
1009 * @param outputs linked list to the outputs of the graph
1010 * @return zero on success, a negative AVERROR code on error
1012 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
1013 AVFilterInOut *inputs, AVFilterInOut *outputs,
1017 * Add a graph described by a string to a graph.
1019 * In the graph filters description, if the input label of the first
1020 * filter is not specified, "in" is assumed; if the output label of
1021 * the last filter is not specified, "out" is assumed.
1023 * @param graph the filter graph where to link the parsed graph context
1024 * @param filters string to be parsed
1025 * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
1026 * If non-NULL, *inputs is updated to contain the list of open inputs
1027 * after the parsing, should be freed with avfilter_inout_free().
1028 * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
1029 * If non-NULL, *outputs is updated to contain the list of open outputs
1030 * after the parsing, should be freed with avfilter_inout_free().
1031 * @return non negative on success, a negative AVERROR code on error
1033 int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters,
1034 AVFilterInOut **inputs, AVFilterInOut **outputs,
1038 * Add a graph described by a string to a graph.
1040 * @param[in] graph the filter graph where to link the parsed graph context
1041 * @param[in] filters string to be parsed
1042 * @param[out] inputs a linked list of all free (unlinked) inputs of the
1043 * parsed graph will be returned here. It is to be freed
1044 * by the caller using avfilter_inout_free().
1045 * @param[out] outputs a linked list of all free (unlinked) outputs of the
1046 * parsed graph will be returned here. It is to be freed by the
1047 * caller using avfilter_inout_free().
1048 * @return zero on success, a negative AVERROR code on error
1050 * @note This function returns the inputs and outputs that are left
1051 * unlinked after parsing the graph and the caller then deals with
1053 * @note This function makes no reference whatsoever to already
1054 * existing parts of the graph and the inputs parameter will on return
1055 * contain inputs of the newly parsed part of the graph. Analogously
1056 * the outputs parameter will contain outputs of the newly created
1059 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
1060 AVFilterInOut **inputs,
1061 AVFilterInOut **outputs);
1064 * Send a command to one or more filter instances.
1066 * @param graph the filter graph
1067 * @param target the filter(s) to which the command should be sent
1068 * "all" sends to all filters
1069 * otherwise it can be a filter or filter instance name
1070 * which will send the command to all matching filters.
1071 * @param cmd the command to send, for handling simplicity all commands must be alphanumeric only
1072 * @param arg the argument for the command
1073 * @param res a buffer with size res_size where the filter(s) can return a response.
1075 * @returns >=0 on success otherwise an error code.
1076 * AVERROR(ENOSYS) on unsupported commands
1078 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
1081 * Queue a command for one or more filter instances.
1083 * @param graph the filter graph
1084 * @param target the filter(s) to which the command should be sent
1085 * "all" sends to all filters
1086 * otherwise it can be a filter or filter instance name
1087 * which will send the command to all matching filters.
1088 * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
1089 * @param arg the argument for the command
1090 * @param ts time at which the command should be sent to the filter
1092 * @note As this executes commands after this function returns, no return code
1093 * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
1095 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
1099 * Dump a graph into a human-readable string representation.
1101 * @param graph the graph to dump
1102 * @param options formatting options; currently ignored
1103 * @return a string, or NULL in case of memory allocation failure;
1104 * the string must be freed using av_free
1106 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
1109 * Request a frame on the oldest sink link.
1111 * If the request returns AVERROR_EOF, try the next.
1113 * Note that this function is not meant to be the sole scheduling mechanism
1114 * of a filtergraph, only a convenience function to help drain a filtergraph
1115 * in a balanced way under normal circumstances.
1117 * Also note that AVERROR_EOF does not mean that frames did not arrive on
1118 * some of the sinks during the process.
1119 * When there are multiple sink links, in case the requested link
1120 * returns an EOF, this may cause a filter to flush pending frames
1121 * which are sent to another sink link, although unrequested.
1123 * @return the return value of ff_request_frame(),
1124 * or AVERROR_EOF if all links returned AVERROR_EOF
1126 int avfilter_graph_request_oldest(AVFilterGraph *graph);
1132 #endif /* AVFILTER_AVFILTER_H */