FFmpeg
avfilter.h
Go to the documentation of this file.
1 /*
2  * filter layer
3  * Copyright (c) 2007 Bobby Bingham
4  *
5  * This file is part of FFmpeg.
6  *
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.
11  *
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.
16  *
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
20  */
21 
22 #ifndef AVFILTER_AVFILTER_H
23 #define AVFILTER_AVFILTER_H
24 
25 /**
26  * @file
27  * @ingroup lavfi
28  * Main libavfilter public API header
29  */
30 
31 /**
32  * @defgroup lavfi libavfilter
33  * Graph-based frame editing library.
34  *
35  * @{
36  */
37 
38 #include <stddef.h>
39 
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"
49 
50 #include "libavfilter/version.h"
51 
52 /**
53  * Return the LIBAVFILTER_VERSION_INT constant.
54  */
55 unsigned avfilter_version(void);
56 
57 /**
58  * Return the libavfilter build-time configuration.
59  */
60 const char *avfilter_configuration(void);
61 
62 /**
63  * Return the libavfilter license.
64  */
65 const char *avfilter_license(void);
66 
67 typedef struct AVFilterContext AVFilterContext;
68 typedef struct AVFilterLink AVFilterLink;
69 typedef struct AVFilterPad AVFilterPad;
72 
73 /**
74  * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
75  * AVFilter.inputs/outputs).
76  */
77 int avfilter_pad_count(const AVFilterPad *pads);
78 
79 /**
80  * Get the name of an AVFilterPad.
81  *
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
85  *
86  * @return name of the pad_idx'th pad in pads
87  */
88 const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
89 
90 /**
91  * Get the type of an AVFilterPad.
92  *
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
96  *
97  * @return type of the pad_idx'th pad in pads
98  */
99 enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
100 
101 /**
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.
105  */
106 #define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
107 /**
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.
111  */
112 #define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
113 /**
114  * The filter supports multithreading by splitting frames into multiple parts
115  * and processing them concurrently.
116  */
117 #define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
118 /**
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
124  * the next filters.
125  */
126 #define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16)
127 /**
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.
133  */
134 #define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)
135 /**
136  * Handy mask to test whether the filter supports or no the timeline feature
137  * (internally or generically).
138  */
139 #define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)
140 
141 /**
142  * Filter definition. This defines the pads a filter contains, and all the
143  * callback functions used to interact with the filter.
144  */
145 typedef struct AVFilter {
146  /**
147  * Filter name. Must be non-NULL and unique among filters.
148  */
149  const char *name;
150 
151  /**
152  * A description of the filter. May be NULL.
153  *
154  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
155  */
156  const char *description;
157 
158  /**
159  * List of inputs, terminated by a zeroed element.
160  *
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
163  * this list.
164  */
166  /**
167  * List of outputs, terminated by a zeroed element.
168  *
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
171  * this list.
172  */
174 
175  /**
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.
178  *
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.
182  */
184 
185  /**
186  * A combination of AVFILTER_FLAG_*
187  */
188  int flags;
189 
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
193  * removed at will.
194  * New public fields should be added right above.
195  *****************************************************************
196  */
197 
198  /**
199  * Filter pre-initialization function
200  *
201  * This callback will be called immediately after the filter context is
202  * allocated, to allow allocating and initing sub-objects.
203  *
204  * If this callback is not NULL, the uninit callback will be called on
205  * allocation failure.
206  *
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)
210  */
211  int (*preinit)(AVFilterContext *ctx);
212 
213  /**
214  * Filter initialization function.
215  *
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.
219  *
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.
224  *
225  * This callback must not assume that the filter links exist or frame
226  * parameters are known.
227  *
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
230  * failure.
231  *
232  * @return 0 on success, a negative AVERROR on failure
233  */
234  int (*init)(AVFilterContext *ctx);
235 
236  /**
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.
240  *
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).
244  *
245  * Otherwise the semantics is the same as for @ref AVFilter.init "init".
246  */
247  int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
248 
249  /**
250  * Filter uninitialization function.
251  *
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.
255  *
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.
258  */
259  void (*uninit)(AVFilterContext *ctx);
260 
261  /**
262  * Query formats supported by the filter on its inputs and outputs.
263  *
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.
267  *
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.
275  *
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
278  * them on output.
279  *
280  * @return zero on success, a negative value corresponding to an
281  * AVERROR code otherwise
282  */
284 
285  int priv_size; ///< size of private data to allocate for the filter
286 
287  int flags_internal; ///< Additional flags for avfilter internal use only.
288 
289 #if FF_API_NEXT
290  /**
291  * Used by the filter registration system. Must not be touched by any other
292  * code.
293  */
294  struct AVFilter *next;
295 #endif
296 
297  /**
298  * Make the filter instance process a command.
299  *
300  * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
301  * @param arg the argument for the command
302  * @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.
303  * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
304  * time consuming then a filter should treat it like an unsupported command
305  *
306  * @returns >=0 on success otherwise an error code.
307  * AVERROR(ENOSYS) on unsupported commands
308  */
309  int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
310 
311  /**
312  * Filter initialization function, alternative to the init()
313  * callback. Args contains the user-supplied parameters, opaque is
314  * used for providing binary data.
315  */
316  int (*init_opaque)(AVFilterContext *ctx, void *opaque);
317 
318  /**
319  * Filter activation function.
320  *
321  * Called when any processing is needed from the filter, instead of any
322  * filter_frame and request_frame on pads.
323  *
324  * The function must examine inlinks and outlinks and perform a single
325  * step of processing. If there is nothing to do, the function must do
326  * nothing and not return an error. If more steps are or may be
327  * possible, it must use ff_filter_set_ready() to schedule another
328  * activation.
329  */
330  int (*activate)(AVFilterContext *ctx);
331 } AVFilter;
332 
333 /**
334  * Process multiple parts of the frame concurrently.
335  */
336 #define AVFILTER_THREAD_SLICE (1 << 0)
337 
339 
340 /** An instance of a filter */
342  const AVClass *av_class; ///< needed for av_log() and filters common options
343 
344  const AVFilter *filter; ///< the AVFilter of which this is an instance
345 
346  char *name; ///< name of this filter instance
347 
348  AVFilterPad *input_pads; ///< array of input pads
349  AVFilterLink **inputs; ///< array of pointers to input links
350  unsigned nb_inputs; ///< number of input pads
351 
352  AVFilterPad *output_pads; ///< array of output pads
353  AVFilterLink **outputs; ///< array of pointers to output links
354  unsigned nb_outputs; ///< number of output pads
355 
356  void *priv; ///< private data for use by the filter
357 
358  struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
359 
360  /**
361  * Type of multithreading being allowed/used. A combination of
362  * AVFILTER_THREAD_* flags.
363  *
364  * May be set by the caller before initializing the filter to forbid some
365  * or all kinds of multithreading for this filter. The default is allowing
366  * everything.
367  *
368  * When the filter is initialized, this field is combined using bit AND with
369  * AVFilterGraph.thread_type to get the final mask used for determining
370  * allowed threading types. I.e. a threading type needs to be set in both
371  * to be allowed.
372  *
373  * After the filter is initialized, libavfilter sets this field to the
374  * threading type that is actually used (0 for no multithreading).
375  */
377 
378  /**
379  * An opaque struct for libavfilter internal use.
380  */
381  AVFilterInternal *internal;
382 
383  struct AVFilterCommand *command_queue;
384 
385  char *enable_str; ///< enable expression string
386  void *enable; ///< parsed expression (AVExpr*)
387  double *var_values; ///< variable values for the enable expression
388  int is_disabled; ///< the enabled state from the last expression evaluation
389 
390  /**
391  * For filters which will create hardware frames, sets the device the
392  * filter should create them in. All other filters will ignore this field:
393  * in particular, a filter which consumes or processes hardware frames will
394  * instead use the hw_frames_ctx field in AVFilterLink to carry the
395  * hardware context information.
396  */
398 
399  /**
400  * Max number of threads allowed in this filter instance.
401  * If <= 0, its value is ignored.
402  * Overrides global number of threads set per filter graph.
403  */
405 
406  /**
407  * Ready status of the filter.
408  * A non-0 value means that the filter needs activating;
409  * a higher value suggests a more urgent activation.
410  */
411  unsigned ready;
412 
413  /**
414  * Sets the number of extra hardware frames which the filter will
415  * allocate on its output links for use in following filters or by
416  * the caller.
417  *
418  * Some hardware filters require all frames that they will use for
419  * output to be defined in advance before filtering starts. For such
420  * filters, any hardware frame pools used for output must therefore be
421  * of fixed size. The extra frames set here are on top of any number
422  * that the filter needs internally in order to operate normally.
423  *
424  * This field must be set before the graph containing this filter is
425  * configured.
426  */
428 };
429 
430 /**
431  * Lists of formats / etc. supported by an end of a link.
432  *
433  * This structure is directly part of AVFilterLink, in two copies:
434  * one for the source filter, one for the destination filter.
435 
436  * These lists are used for negotiating the format to actually be used,
437  * which will be loaded into the format and channel_layout members of
438  * AVFilterLink, when chosen.
439  */
440 typedef struct AVFilterFormatsConfig {
441 
442  /**
443  * List of supported formats (pixel or sample).
444  */
446 
447  /**
448  * Lists of supported sample rates, only for audio.
449  */
451 
452  /**
453  * Lists of supported channel layouts, only for audio.
454  */
456 
458 
459 /**
460  * A link between two filters. This contains pointers to the source and
461  * destination filters between which this link exists, and the indexes of
462  * the pads involved. In addition, this link also contains the parameters
463  * which have been negotiated and agreed upon between the filter, such as
464  * image dimensions, format, etc.
465  *
466  * Applications must not normally access the link structure directly.
467  * Use the buffersrc and buffersink API instead.
468  * In the future, access to the header may be reserved for filters
469  * implementation.
470  */
471 struct AVFilterLink {
472  AVFilterContext *src; ///< source filter
473  AVFilterPad *srcpad; ///< output pad on the source filter
474 
475  AVFilterContext *dst; ///< dest filter
476  AVFilterPad *dstpad; ///< input pad on the dest filter
477 
478  enum AVMediaType type; ///< filter media type
479 
480  /* These parameters apply only to video */
481  int w; ///< agreed upon image width
482  int h; ///< agreed upon image height
483  AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
484  /* These parameters apply only to audio */
485  uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
486  int sample_rate; ///< samples per second
487 
488  int format; ///< agreed upon media format
489 
490  /**
491  * Define the time base used by the PTS of the frames/samples
492  * which will pass through this link.
493  * During the configuration stage, each filter is supposed to
494  * change only the output timebase, while the timebase of the
495  * input link is assumed to be an unchangeable property.
496  */
498 
499  /*****************************************************************
500  * All fields below this line are not part of the public API. They
501  * may not be used outside of libavfilter and can be changed and
502  * removed at will.
503  * New public fields should be added right above.
504  *****************************************************************
505  */
506 
507  /**
508  * Lists of supported formats / etc. supported by the input filter.
509  */
511 
512  /**
513  * Lists of supported formats / etc. supported by the output filter.
514  */
516 
517  /** stage of the initialization of the link properties (dimensions, etc) */
518  enum {
519  AVLINK_UNINIT = 0, ///< not started
520  AVLINK_STARTINIT, ///< started, but incomplete
521  AVLINK_INIT ///< complete
522  } init_state;
523 
524  /**
525  * Graph the filter belongs to.
526  */
528 
529  /**
530  * Current timestamp of the link, as defined by the most recent
531  * frame(s), in link time_base units.
532  */
533  int64_t current_pts;
534 
535  /**
536  * Current timestamp of the link, as defined by the most recent
537  * frame(s), in AV_TIME_BASE units.
538  */
539  int64_t current_pts_us;
540 
541  /**
542  * Index in the age array.
543  */
545 
546  /**
547  * Frame rate of the stream on the link, or 1/0 if unknown or variable;
548  * if left to 0/0, will be automatically copied from the first input
549  * of the source filter if it exists.
550  *
551  * Sources should set it to the best estimation of the real frame rate.
552  * If the source frame rate is unknown or variable, set this to 1/0.
553  * Filters should update it if necessary depending on their function.
554  * Sinks can use it to set a default output frame rate.
555  * It is similar to the r_frame_rate field in AVStream.
556  */
558 
559  /**
560  * Buffer partially filled with samples to achieve a fixed/minimum size.
561  */
563 
564  /**
565  * Size of the partial buffer to allocate.
566  * Must be between min_samples and max_samples.
567  */
569 
570  /**
571  * Minimum number of samples to filter at once. If filter_frame() is
572  * called with fewer samples, it will accumulate them in partial_buf.
573  * This field and the related ones must not be changed after filtering
574  * has started.
575  * If 0, all related fields are ignored.
576  */
578 
579  /**
580  * Maximum number of samples to filter at once. If filter_frame() is
581  * called with more samples, it will split them.
582  */
584 
585  /**
586  * Number of channels.
587  */
588  int channels;
589 
590  /**
591  * Number of past frames sent through the link.
592  */
593  int64_t frame_count_in, frame_count_out;
594 
595  /**
596  * A pointer to a FFFramePool struct.
597  */
598  void *frame_pool;
599 
600  /**
601  * True if a frame is currently wanted on the output of this filter.
602  * Set when ff_request_frame() is called by the output,
603  * cleared when a frame is filtered.
604  */
606 
607  /**
608  * For hwaccel pixel formats, this should be a reference to the
609  * AVHWFramesContext describing the frames.
610  */
612 
613 #ifndef FF_INTERNAL_FIELDS
614 
615  /**
616  * Internal structure members.
617  * The fields below this limit are internal for libavfilter's use
618  * and must in no way be accessed by applications.
619  */
620  char reserved[0xF000];
621 
622 #else /* FF_INTERNAL_FIELDS */
623 
624  /**
625  * Queue of frames waiting to be filtered.
626  */
627  FFFrameQueue fifo;
628 
629  /**
630  * If set, the source filter can not generate a frame as is.
631  * The goal is to avoid repeatedly calling the request_frame() method on
632  * the same link.
633  */
634  int frame_blocked_in;
635 
636  /**
637  * Link input status.
638  * If not zero, all attempts of filter_frame will fail with the
639  * corresponding code.
640  */
641  int status_in;
642 
643  /**
644  * Timestamp of the input status change.
645  */
646  int64_t status_in_pts;
647 
648  /**
649  * Link output status.
650  * If not zero, all attempts of request_frame will fail with the
651  * corresponding code.
652  */
653  int status_out;
654 
655 #endif /* FF_INTERNAL_FIELDS */
656 
657 };
658 
659 /**
660  * Link two filters together.
661  *
662  * @param src the source filter
663  * @param srcpad index of the output pad on the source filter
664  * @param dst the destination filter
665  * @param dstpad index of the input pad on the destination filter
666  * @return zero on success
667  */
668 int avfilter_link(AVFilterContext *src, unsigned srcpad,
669  AVFilterContext *dst, unsigned dstpad);
670 
671 /**
672  * Free the link in *link, and set its pointer to NULL.
673  */
674 void avfilter_link_free(AVFilterLink **link);
675 
676 #if FF_API_FILTER_GET_SET
677 /**
678  * Get the number of channels of a link.
679  * @deprecated Use av_buffersink_get_channels()
680  */
683 #endif
684 #if FF_API_FILTER_LINK_SET_CLOSED
685 /**
686  * Set the closed field of a link.
687  * @deprecated applications are not supposed to mess with links, they should
688  * close the sinks.
689  */
691 void avfilter_link_set_closed(AVFilterLink *link, int closed);
692 #endif
693 /**
694  * Negotiate the media format, dimensions, etc of all inputs to a filter.
695  *
696  * @param filter the filter to negotiate the properties for its inputs
697  * @return zero on successful negotiation
698  */
700 
701 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
702 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
703 
704 /**
705  * Make the filter instance process a command.
706  * It is recommended to use avfilter_graph_send_command().
707  */
708 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
709 
710 /**
711  * Iterate over all registered filters.
712  *
713  * @param opaque a pointer where libavfilter will store the iteration state. Must
714  * point to NULL to start the iteration.
715  *
716  * @return the next registered filter or NULL when the iteration is
717  * finished
718  */
719 const AVFilter *av_filter_iterate(void **opaque);
720 
721 #if FF_API_NEXT
722 /** Initialize the filter system. Register all builtin filters. */
724 void avfilter_register_all(void);
725 
726 /**
727  * Register a filter. This is only needed if you plan to use
728  * avfilter_get_by_name later to lookup the AVFilter structure by name. A
729  * filter can still by instantiated with avfilter_graph_alloc_filter even if it
730  * is not registered.
731  *
732  * @param filter the filter to register
733  * @return 0 if the registration was successful, a negative value
734  * otherwise
735  */
737 int avfilter_register(AVFilter *filter);
738 
739 /**
740  * Iterate over all registered filters.
741  * @return If prev is non-NULL, next registered filter after prev or NULL if
742  * prev is the last filter. If prev is NULL, return the first registered filter.
743  */
745 const AVFilter *avfilter_next(const AVFilter *prev);
746 #endif
747 
748 /**
749  * Get a filter definition matching the given name.
750  *
751  * @param name the filter name to find
752  * @return the filter definition, if any matching one is registered.
753  * NULL if none found.
754  */
755 const AVFilter *avfilter_get_by_name(const char *name);
756 
757 
758 /**
759  * Initialize a filter with the supplied parameters.
760  *
761  * @param ctx uninitialized filter context to initialize
762  * @param args Options to initialize the filter with. This must be a
763  * ':'-separated list of options in the 'key=value' form.
764  * May be NULL if the options have been set directly using the
765  * AVOptions API or there are no options that need to be set.
766  * @return 0 on success, a negative AVERROR on failure
767  */
768 int avfilter_init_str(AVFilterContext *ctx, const char *args);
769 
770 /**
771  * Initialize a filter with the supplied dictionary of options.
772  *
773  * @param ctx uninitialized filter context to initialize
774  * @param options An AVDictionary filled with options for this filter. On
775  * return this parameter will be destroyed and replaced with
776  * a dict containing options that were not found. This dictionary
777  * must be freed by the caller.
778  * May be NULL, then this function is equivalent to
779  * avfilter_init_str() with the second parameter set to NULL.
780  * @return 0 on success, a negative AVERROR on failure
781  *
782  * @note This function and avfilter_init_str() do essentially the same thing,
783  * the difference is in manner in which the options are passed. It is up to the
784  * calling code to choose whichever is more preferable. The two functions also
785  * behave differently when some of the provided options are not declared as
786  * supported by the filter. In such a case, avfilter_init_str() will fail, but
787  * this function will leave those extra options in the options AVDictionary and
788  * continue as usual.
789  */
790 int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options);
791 
792 /**
793  * Free a filter context. This will also remove the filter from its
794  * filtergraph's list of filters.
795  *
796  * @param filter the filter to free
797  */
798 void avfilter_free(AVFilterContext *filter);
799 
800 /**
801  * Insert a filter in the middle of an existing link.
802  *
803  * @param link the link into which the filter should be inserted
804  * @param filt the filter to be inserted
805  * @param filt_srcpad_idx the input pad on the filter to connect
806  * @param filt_dstpad_idx the output pad on the filter to connect
807  * @return zero on success
808  */
810  unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
811 
812 /**
813  * @return AVClass for AVFilterContext.
814  *
815  * @see av_opt_find().
816  */
817 const AVClass *avfilter_get_class(void);
818 
820 
821 /**
822  * A function pointer passed to the @ref AVFilterGraph.execute callback to be
823  * executed multiple times, possibly in parallel.
824  *
825  * @param ctx the filter context the job belongs to
826  * @param arg an opaque parameter passed through from @ref
827  * AVFilterGraph.execute
828  * @param jobnr the index of the job being executed
829  * @param nb_jobs the total number of jobs
830  *
831  * @return 0 on success, a negative AVERROR on error
832  */
833 typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
834 
835 /**
836  * A function executing multiple jobs, possibly in parallel.
837  *
838  * @param ctx the filter context to which the jobs belong
839  * @param func the function to be called multiple times
840  * @param arg the argument to be passed to func
841  * @param ret a nb_jobs-sized array to be filled with return values from each
842  * invocation of func
843  * @param nb_jobs the number of jobs to execute
844  *
845  * @return 0 on success, a negative AVERROR on error
846  */
848  void *arg, int *ret, int nb_jobs);
849 
850 typedef struct AVFilterGraph {
853  unsigned nb_filters;
854 
855  char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
856 #if FF_API_LAVR_OPTS
857  attribute_deprecated char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
858 #endif
859 
860  /**
861  * Type of multithreading allowed for filters in this graph. A combination
862  * of AVFILTER_THREAD_* flags.
863  *
864  * May be set by the caller at any point, the setting will apply to all
865  * filters initialized after that. The default is allowing everything.
866  *
867  * When a filter in this graph is initialized, this field is combined using
868  * bit AND with AVFilterContext.thread_type to get the final mask used for
869  * determining allowed threading types. I.e. a threading type needs to be
870  * set in both to be allowed.
871  */
873 
874  /**
875  * Maximum number of threads used by filters in this graph. May be set by
876  * the caller before adding any filters to the filtergraph. Zero (the
877  * default) means that the number of threads is determined automatically.
878  */
880 
881  /**
882  * Opaque object for libavfilter internal use.
883  */
885 
886  /**
887  * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
888  * be used from callbacks like @ref AVFilterGraph.execute.
889  * Libavfilter will not touch this field in any way.
890  */
891  void *opaque;
892 
893  /**
894  * This callback may be set by the caller immediately after allocating the
895  * graph and before adding any filters to it, to provide a custom
896  * multithreading implementation.
897  *
898  * If set, filters with slice threading capability will call this callback
899  * to execute multiple jobs in parallel.
900  *
901  * If this field is left unset, libavfilter will use its internal
902  * implementation, which may or may not be multithreaded depending on the
903  * platform and build options.
904  */
906 
907  char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
908 
909  /**
910  * Private fields
911  *
912  * The following fields are for internal use only.
913  * Their type, offset, number and semantic can change without notice.
914  */
915 
918 
920 } AVFilterGraph;
921 
922 /**
923  * Allocate a filter graph.
924  *
925  * @return the allocated filter graph on success or NULL.
926  */
928 
929 /**
930  * Create a new filter instance in a filter graph.
931  *
932  * @param graph graph in which the new filter will be used
933  * @param filter the filter to create an instance of
934  * @param name Name to give to the new instance (will be copied to
935  * AVFilterContext.name). This may be used by the caller to identify
936  * different filters, libavfilter itself assigns no semantics to
937  * this parameter. May be NULL.
938  *
939  * @return the context of the newly created filter instance (note that it is
940  * also retrievable directly through AVFilterGraph.filters or with
941  * avfilter_graph_get_filter()) on success or NULL on failure.
942  */
944  const AVFilter *filter,
945  const char *name);
946 
947 /**
948  * Get a filter instance identified by instance name from graph.
949  *
950  * @param graph filter graph to search through.
951  * @param name filter instance name (should be unique in the graph).
952  * @return the pointer to the found filter instance or NULL if it
953  * cannot be found.
954  */
956 
957 /**
958  * Create and add a filter instance into an existing graph.
959  * The filter instance is created from the filter filt and inited
960  * with the parameter args. opaque is currently ignored.
961  *
962  * In case of success put in *filt_ctx the pointer to the created
963  * filter instance, otherwise set *filt_ctx to NULL.
964  *
965  * @param name the instance name to give to the created filter instance
966  * @param graph_ctx the filter graph
967  * @return a negative AVERROR error code in case of failure, a non
968  * negative value otherwise
969  */
970 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
971  const char *name, const char *args, void *opaque,
972  AVFilterGraph *graph_ctx);
973 
974 /**
975  * Enable or disable automatic format conversion inside the graph.
976  *
977  * Note that format conversion can still happen inside explicitly inserted
978  * scale and aresample filters.
979  *
980  * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
981  */
983 
984 enum {
985  AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
986  AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
987 };
988 
989 /**
990  * Check validity and configure all the links and formats in the graph.
991  *
992  * @param graphctx the filter graph
993  * @param log_ctx context used for logging
994  * @return >= 0 in case of success, a negative AVERROR code otherwise
995  */
996 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
997 
998 /**
999  * Free a graph, destroy its links, and set *graph to NULL.
1000  * If *graph is NULL, do nothing.
1001  */
1002 void avfilter_graph_free(AVFilterGraph **graph);
1003 
1004 /**
1005  * A linked-list of the inputs/outputs of the filter chain.
1006  *
1007  * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
1008  * where it is used to communicate open (unlinked) inputs and outputs from and
1009  * to the caller.
1010  * This struct specifies, per each not connected pad contained in the graph, the
1011  * filter context and the pad index required for establishing a link.
1012  */
1013 typedef struct AVFilterInOut {
1014  /** unique name for this input/output in the list */
1015  char *name;
1016 
1017  /** filter context associated to this input/output */
1019 
1020  /** index of the filt_ctx pad to use for linking */
1021  int pad_idx;
1022 
1023  /** next input/input in the list, NULL if this is the last */
1025 } AVFilterInOut;
1026 
1027 /**
1028  * Allocate a single AVFilterInOut entry.
1029  * Must be freed with avfilter_inout_free().
1030  * @return allocated AVFilterInOut on success, NULL on failure.
1031  */
1033 
1034 /**
1035  * Free the supplied list of AVFilterInOut and set *inout to NULL.
1036  * If *inout is NULL, do nothing.
1037  */
1038 void avfilter_inout_free(AVFilterInOut **inout);
1039 
1040 /**
1041  * Add a graph described by a string to a graph.
1042  *
1043  * @note The caller must provide the lists of inputs and outputs,
1044  * which therefore must be known before calling the function.
1045  *
1046  * @note The inputs parameter describes inputs of the already existing
1047  * part of the graph; i.e. from the point of view of the newly created
1048  * part, they are outputs. Similarly the outputs parameter describes
1049  * outputs of the already existing filters, which are provided as
1050  * inputs to the parsed filters.
1051  *
1052  * @param graph the filter graph where to link the parsed graph context
1053  * @param filters string to be parsed
1054  * @param inputs linked list to the inputs of the graph
1055  * @param outputs linked list to the outputs of the graph
1056  * @return zero on success, a negative AVERROR code on error
1057  */
1058 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
1060  void *log_ctx);
1061 
1062 /**
1063  * Add a graph described by a string to a graph.
1064  *
1065  * In the graph filters description, if the input label of the first
1066  * filter is not specified, "in" is assumed; if the output label of
1067  * the last filter is not specified, "out" is assumed.
1068  *
1069  * @param graph the filter graph where to link the parsed graph context
1070  * @param filters string to be parsed
1071  * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
1072  * If non-NULL, *inputs is updated to contain the list of open inputs
1073  * after the parsing, should be freed with avfilter_inout_free().
1074  * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
1075  * If non-NULL, *outputs is updated to contain the list of open outputs
1076  * after the parsing, should be freed with avfilter_inout_free().
1077  * @return non negative on success, a negative AVERROR code on error
1078  */
1079 int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters,
1081  void *log_ctx);
1082 
1083 /**
1084  * Add a graph described by a string to a graph.
1085  *
1086  * @param[in] graph the filter graph where to link the parsed graph context
1087  * @param[in] filters string to be parsed
1088  * @param[out] inputs a linked list of all free (unlinked) inputs of the
1089  * parsed graph will be returned here. It is to be freed
1090  * by the caller using avfilter_inout_free().
1091  * @param[out] outputs a linked list of all free (unlinked) outputs of the
1092  * parsed graph will be returned here. It is to be freed by the
1093  * caller using avfilter_inout_free().
1094  * @return zero on success, a negative AVERROR code on error
1095  *
1096  * @note This function returns the inputs and outputs that are left
1097  * unlinked after parsing the graph and the caller then deals with
1098  * them.
1099  * @note This function makes no reference whatsoever to already
1100  * existing parts of the graph and the inputs parameter will on return
1101  * contain inputs of the newly parsed part of the graph. Analogously
1102  * the outputs parameter will contain outputs of the newly created
1103  * filters.
1104  */
1105 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
1108 
1109 /**
1110  * Send a command to one or more filter instances.
1111  *
1112  * @param graph the filter graph
1113  * @param target the filter(s) to which the command should be sent
1114  * "all" sends to all filters
1115  * otherwise it can be a filter or filter instance name
1116  * which will send the command to all matching filters.
1117  * @param cmd the command to send, for handling simplicity all commands must be alphanumeric only
1118  * @param arg the argument for the command
1119  * @param res a buffer with size res_size where the filter(s) can return a response.
1120  *
1121  * @returns >=0 on success otherwise an error code.
1122  * AVERROR(ENOSYS) on unsupported commands
1123  */
1124 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
1125 
1126 /**
1127  * Queue a command for one or more filter instances.
1128  *
1129  * @param graph the filter graph
1130  * @param target the filter(s) to which the command should be sent
1131  * "all" sends to all filters
1132  * otherwise it can be a filter or filter instance name
1133  * which will send the command to all matching filters.
1134  * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
1135  * @param arg the argument for the command
1136  * @param ts time at which the command should be sent to the filter
1137  *
1138  * @note As this executes commands after this function returns, no return code
1139  * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
1140  */
1141 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
1142 
1143 
1144 /**
1145  * Dump a graph into a human-readable string representation.
1146  *
1147  * @param graph the graph to dump
1148  * @param options formatting options; currently ignored
1149  * @return a string, or NULL in case of memory allocation failure;
1150  * the string must be freed using av_free
1151  */
1152 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
1153 
1154 /**
1155  * Request a frame on the oldest sink link.
1156  *
1157  * If the request returns AVERROR_EOF, try the next.
1158  *
1159  * Note that this function is not meant to be the sole scheduling mechanism
1160  * of a filtergraph, only a convenience function to help drain a filtergraph
1161  * in a balanced way under normal circumstances.
1162  *
1163  * Also note that AVERROR_EOF does not mean that frames did not arrive on
1164  * some of the sinks during the process.
1165  * When there are multiple sink links, in case the requested link
1166  * returns an EOF, this may cause a filter to flush pending frames
1167  * which are sent to another sink link, although unrequested.
1168  *
1169  * @return the return value of ff_request_frame(),
1170  * or AVERROR_EOF if all links returned AVERROR_EOF
1171  */
1173 
1174 /**
1175  * @}
1176  */
1177 
1178 #endif /* AVFILTER_AVFILTER_H */
AVFilterContext ** filters
Definition: avfilter.h:852
void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags)
Enable or disable automatic format conversion inside the graph.
Lists of formats / etc.
Definition: avfilter.h:440
attribute_deprecated char * resample_lavr_opts
libavresample options to use for the auto-inserted resample filters
Definition: avfilter.h:857
double * var_values
variable values for the enable expression
Definition: avfilter.h:387
struct AVFilterInternal AVFilterInternal
Definition: avfilter.h:338
all automatic conversions enabled
Definition: avfilter.h:985
int sink_links_count
Definition: avfilter.h:917
This structure describes decoded (raw) audio or video data.
Definition: frame.h:318
int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts)
Queue a command for one or more filter instances.
int thread_type
Type of multithreading allowed for filters in this graph.
Definition: avfilter.h:872
void avfilter_free(AVFilterContext *filter)
Free a filter context.
AVFilterGraph * avfilter_graph_alloc(void)
Allocate a filter graph.
int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
Check validity and configure all the links and formats in the graph.
void avfilter_inout_free(AVFilterInOut **inout)
Free the supplied list of AVFilterInOut and set *inout to NULL.
struct AVFilterInOut * next
next input/input in the list, NULL if this is the last
Definition: avfilter.h:1024
enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx)
Get the type of an AVFilterPad.
Libavfilter version macros.
int() avfilter_execute_func(AVFilterContext *ctx, avfilter_action_func *func, void *arg, int *ret, int nb_jobs)
A function executing multiple jobs, possibly in parallel.
Definition: avfilter.h:847
void avfilter_graph_free(AVFilterGraph **graph)
Free a graph, destroy its links, and set *graph to NULL.
AVBufferRef * hw_device_ctx
For filters which will create hardware frames, sets the device the filter should create them in...
Definition: avfilter.h:397
Convenience header that includes libavutil&#39;s core.
int(* activate)(AVFilterContext *ctx)
Filter activation function.
Definition: avfilter.h:330
int thread_type
Type of multithreading being allowed/used.
Definition: avfilter.h:376
void(* uninit)(AVFilterContext *ctx)
Filter uninitialization function.
Definition: avfilter.h:259
int is_disabled
the enabled state from the last expression evaluation
Definition: avfilter.h:388
Macro definitions for various function/variable attributes.
int nb_threads
Max number of threads allowed in this filter instance.
Definition: avfilter.h:404
char * scale_sws_opts
sws options to use for the auto-inserted scale filters
Definition: avfilter.h:855
struct AVFilterGraph * graph
filtergraph this filter belongs to
Definition: avfilter.h:358
int(* init_dict)(AVFilterContext *ctx, AVDictionary **options)
Should be set instead of init by the filters that want to pass a dictionary of AVOptions to nested co...
Definition: avfilter.h:247
int priv_size
size of private data to allocate for the filter
Definition: avfilter.h:285
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:349
char * name
name of this filter instance
Definition: avfilter.h:346
Public dictionary API.
avfilter_execute_func * execute
This callback may be set by the caller immediately after allocating the graph and before adding any f...
Definition: avfilter.h:905
int avfilter_link(AVFilterContext *src, unsigned srcpad, AVFilterContext *dst, unsigned dstpad)
Link two filters together.
AVFilterPad * output_pads
array of output pads
Definition: avfilter.h:352
const char * avfilter_license(void)
Return the libavfilter license.
unsigned ready
Ready status of the filter.
Definition: avfilter.h:411
int flags
A combination of AVFILTER_FLAG_*.
Definition: avfilter.h:188
int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt, const char *name, const char *args, void *opaque, AVFilterGraph *graph_ctx)
Create and add a filter instance into an existing graph.
int nb_threads
Maximum number of threads used by filters in this graph.
Definition: avfilter.h:879
int avfilter_config_links(AVFilterContext *filter)
Negotiate the media format, dimensions, etc of all inputs to a filter.
struct AVFilterChannelLayouts AVFilterChannelLayouts
Definition: avfilter.h:71
AVFilterContext * avfilter_graph_get_filter(AVFilterGraph *graph, const char *name)
Get a filter instance identified by instance name from graph.
int(* preinit)(AVFilterContext *ctx)
Filter pre-initialization function.
Definition: avfilter.h:211
int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters, AVFilterInOut **inputs, AVFilterInOut **outputs)
Add a graph described by a string to a graph.
int extra_hw_frames
Sets the number of extra hardware frames which the filter will allocate on its output links for use i...
Definition: avfilter.h:427
AVFilterPad * input_pads
array of input pads
Definition: avfilter.h:348
const AVClass * av_class
Definition: avfilter.h:851
unsigned nb_outputs
number of output pads
Definition: avfilter.h:354
unsigned avfilter_version(void)
Return the LIBAVFILTER_VERSION_INT constant.
void * priv
private data for use by the filter
Definition: avfilter.h:356
AVFilterFormats * formats
List of supported formats (pixel or sample).
Definition: avfilter.h:445
struct AVDictionary AVDictionary
Definition: dict.h:90
char * enable_str
enable expression string
Definition: avfilter.h:385
AVFilterLink ** sink_links
Private fields.
Definition: avfilter.h:916
reference-counted frame API
const AVFilter * avfilter_get_by_name(const char *name)
Get a filter definition matching the given name.
attribute_deprecated void avfilter_link_set_closed(AVFilterLink *link, int closed)
Set the closed field of a link.
attribute_deprecated void avfilter_register_all(void)
Initialize the filter system.
unsigned nb_inputs
number of input pads
Definition: avfilter.h:350
AVFilterChannelLayouts * channel_layouts
Lists of supported channel layouts, only for audio.
Definition: avfilter.h:455
int() avfilter_action_func(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
A function pointer passed to the AVFilterGraph::execute callback to be executed multiple times...
Definition: avfilter.h:833
int(* init)(AVFilterContext *ctx)
Filter initialization function.
Definition: avfilter.h:234
int flags_internal
Additional flags for avfilter internal use only.
Definition: avfilter.h:287
AVFilterFormats * samplerates
Lists of supported sample rates, only for audio.
Definition: avfilter.h:450
AVFilterContext * filter_ctx
filter context associated to this input/output
Definition: avfilter.h:1018
int avfilter_init_str(AVFilterContext *ctx, const char *args)
Initialize a filter with the supplied parameters.
const AVFilterPad * inputs
List of inputs, terminated by a zeroed element.
Definition: avfilter.h:165
const AVClass * avfilter_get_class(void)
A linked-list of the inputs/outputs of the filter chain.
Definition: avfilter.h:1013
int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt, unsigned filt_srcpad_idx, unsigned filt_dstpad_idx)
Insert a filter in the middle of an existing link.
const AVClass * priv_class
A class for the private data, used to declare filter private AVOptions.
Definition: avfilter.h:183
int(* process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags)
Make the filter instance process a command.
Definition: avfilter.h:309
int avfilter_graph_request_oldest(AVFilterGraph *graph)
Request a frame on the oldest sink link.
int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags)
Make the filter instance process a command.
int avfilter_graph_parse(AVFilterGraph *graph, const char *filters, AVFilterInOut *inputs, AVFilterInOut *outputs, void *log_ctx)
Add a graph described by a string to a graph.
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:145
int pad_idx
index of the filt_ctx pad to use for linking
Definition: avfilter.h:1021
attribute_deprecated int avfilter_link_get_channels(AVFilterLink *link)
Get the number of channels of a link.
Rational number (pair of numerator and denominator).
Definition: rational.h:58
const AVFilter * av_filter_iterate(void **opaque)
Iterate over all registered filters.
int(* query_formats)(AVFilterContext *)
Query formats supported by the filter on its inputs and outputs.
Definition: avfilter.h:283
struct AVFilter * next
Used by the filter registration system.
Definition: avfilter.h:294
AVMediaType
Definition: avutil.h:199
refcounted data buffer API
const char * name
Filter name.
Definition: avfilter.h:149
unsigned nb_filters
Definition: avfilter.h:853
const char * avfilter_configuration(void)
Return the libavfilter build-time configuration.
const char * avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx)
Get the name of an AVFilterPad.
attribute_deprecated int avfilter_register(AVFilter *filter)
Register a filter.
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:353
attribute_deprecated const AVFilter * avfilter_next(const AVFilter *prev)
Iterate over all registered filters.
char * name
unique name for this input/output in the list
Definition: avfilter.h:1015
int(* init_opaque)(AVFilterContext *ctx, void *opaque)
Filter initialization function, alternative to the init() callback.
Definition: avfilter.h:316
#define attribute_deprecated
Definition: attributes.h:100
int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options)
Initialize a filter with the supplied dictionary of options.
A reference to a data buffer.
Definition: buffer.h:84
void * opaque
Opaque user data.
Definition: avfilter.h:891
AVFilterInOut * avfilter_inout_alloc(void)
Allocate a single AVFilterInOut entry.
Utilties for rational number calculation.
struct AVFilterCommand * command_queue
Definition: avfilter.h:383
char * avfilter_graph_dump(AVFilterGraph *graph, const char *options)
Dump a graph into a human-readable string representation.
int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags)
Send a command to one or more filter instances.
struct AVFilterPad AVFilterPad
Definition: avfilter.h:69
char * aresample_swr_opts
swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions ...
Definition: avfilter.h:907
pixel format definitions
const char * description
A description of the filter.
Definition: avfilter.h:156
AVFilterContext * avfilter_graph_alloc_filter(AVFilterGraph *graph, const AVFilter *filter, const char *name)
Create a new filter instance in a filter graph.
void * enable
parsed expression (AVExpr*)
Definition: avfilter.h:386
const AVClass * av_class
needed for av_log() and filters common options
Definition: avfilter.h:342
struct AVFilterGraphInternal AVFilterGraphInternal
Definition: avfilter.h:819
int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters, AVFilterInOut **inputs, AVFilterInOut **outputs, void *log_ctx)
Add a graph described by a string to a graph.
An instance of a filter.
Definition: avfilter.h:341
all automatic conversions disabled
Definition: avfilter.h:986
int avfilter_pad_count(const AVFilterPad *pads)
Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
const AVFilterPad * outputs
List of outputs, terminated by a zeroed element.
Definition: avfilter.h:173
void avfilter_link_free(AVFilterLink **link)
Free the link in *link, and set its pointer to NULL.
const AVFilter * filter
the AVFilter of which this is an instance
Definition: avfilter.h:344
unsigned disable_auto_convert
Definition: avfilter.h:919
struct AVFilterFormats AVFilterFormats
Definition: avfilter.h:70