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avfilter.h
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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;
70 typedef struct AVFilterFormats AVFilterFormats;
71 
72 /**
73  * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
74  * AVFilter.inputs/outputs).
75  */
76 int avfilter_pad_count(const AVFilterPad *pads);
77 
78 /**
79  * Get the name of an AVFilterPad.
80  *
81  * @param pads an array of AVFilterPads
82  * @param pad_idx index of the pad in the array it; is the caller's
83  * responsibility to ensure the index is valid
84  *
85  * @return name of the pad_idx'th pad in pads
86  */
87 const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
88 
89 /**
90  * Get the type of an AVFilterPad.
91  *
92  * @param pads an array of AVFilterPads
93  * @param pad_idx index of the pad in the array; it is the caller's
94  * responsibility to ensure the index is valid
95  *
96  * @return type of the pad_idx'th pad in pads
97  */
98 enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
99 
100 /**
101  * The number of the filter inputs is not determined just by AVFilter.inputs.
102  * The filter might add additional inputs during initialization depending on the
103  * options supplied to it.
104  */
105 #define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
106 /**
107  * The number of the filter outputs is not determined just by AVFilter.outputs.
108  * The filter might add additional outputs during initialization depending on
109  * the options supplied to it.
110  */
111 #define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
112 /**
113  * The filter supports multithreading by splitting frames into multiple parts
114  * and processing them concurrently.
115  */
116 #define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
117 /**
118  * Some filters support a generic "enable" expression option that can be used
119  * to enable or disable a filter in the timeline. Filters supporting this
120  * option have this flag set. When the enable expression is false, the default
121  * no-op filter_frame() function is called in place of the filter_frame()
122  * callback defined on each input pad, thus the frame is passed unchanged to
123  * the next filters.
124  */
125 #define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16)
126 /**
127  * Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will
128  * have its filter_frame() callback(s) called as usual even when the enable
129  * expression is false. The filter will disable filtering within the
130  * filter_frame() callback(s) itself, for example executing code depending on
131  * the AVFilterContext->is_disabled value.
132  */
133 #define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)
134 /**
135  * Handy mask to test whether the filter supports or no the timeline feature
136  * (internally or generically).
137  */
138 #define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)
139 
140 /**
141  * Filter definition. This defines the pads a filter contains, and all the
142  * callback functions used to interact with the filter.
143  */
144 typedef struct AVFilter {
145  /**
146  * Filter name. Must be non-NULL and unique among filters.
147  */
148  const char *name;
149 
150  /**
151  * A description of the filter. May be NULL.
152  *
153  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
154  */
155  const char *description;
156 
157  /**
158  * List of inputs, terminated by a zeroed element.
159  *
160  * NULL if there are no (static) inputs. Instances of filters with
161  * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in
162  * this list.
163  */
165  /**
166  * List of outputs, terminated by a zeroed element.
167  *
168  * NULL if there are no (static) outputs. Instances of filters with
169  * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in
170  * this list.
171  */
173 
174  /**
175  * A class for the private data, used to declare filter private AVOptions.
176  * This field is NULL for filters that do not declare any options.
177  *
178  * If this field is non-NULL, the first member of the filter private data
179  * must be a pointer to AVClass, which will be set by libavfilter generic
180  * code to this class.
181  */
183 
184  /**
185  * A combination of AVFILTER_FLAG_*
186  */
187  int flags;
188 
189  /*****************************************************************
190  * All fields below this line are not part of the public API. They
191  * may not be used outside of libavfilter and can be changed and
192  * removed at will.
193  * New public fields should be added right above.
194  *****************************************************************
195  */
196 
197  /**
198  * Filter initialization function.
199  *
200  * This callback will be called only once during the filter lifetime, after
201  * all the options have been set, but before links between filters are
202  * established and format negotiation is done.
203  *
204  * Basic filter initialization should be done here. Filters with dynamic
205  * inputs and/or outputs should create those inputs/outputs here based on
206  * provided options. No more changes to this filter's inputs/outputs can be
207  * done after this callback.
208  *
209  * This callback must not assume that the filter links exist or frame
210  * parameters are known.
211  *
212  * @ref AVFilter.uninit "uninit" is guaranteed to be called even if
213  * initialization fails, so this callback does not have to clean up on
214  * failure.
215  *
216  * @return 0 on success, a negative AVERROR on failure
217  */
219 
220  /**
221  * Should be set instead of @ref AVFilter.init "init" by the filters that
222  * want to pass a dictionary of AVOptions to nested contexts that are
223  * allocated during init.
224  *
225  * On return, the options dict should be freed and replaced with one that
226  * contains all the options which could not be processed by this filter (or
227  * with NULL if all the options were processed).
228  *
229  * Otherwise the semantics is the same as for @ref AVFilter.init "init".
230  */
232 
233  /**
234  * Filter uninitialization function.
235  *
236  * Called only once right before the filter is freed. Should deallocate any
237  * memory held by the filter, release any buffer references, etc. It does
238  * not need to deallocate the AVFilterContext.priv memory itself.
239  *
240  * This callback may be called even if @ref AVFilter.init "init" was not
241  * called or failed, so it must be prepared to handle such a situation.
242  */
244 
245  /**
246  * Query formats supported by the filter on its inputs and outputs.
247  *
248  * This callback is called after the filter is initialized (so the inputs
249  * and outputs are fixed), shortly before the format negotiation. This
250  * callback may be called more than once.
251  *
252  * This callback must set AVFilterLink.out_formats on every input link and
253  * AVFilterLink.in_formats on every output link to a list of pixel/sample
254  * formats that the filter supports on that link. For audio links, this
255  * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" /
256  * @ref AVFilterLink.out_samplerates "out_samplerates" and
257  * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" /
258  * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously.
259  *
260  * This callback may be NULL for filters with one input, in which case
261  * libavfilter assumes that it supports all input formats and preserves
262  * them on output.
263  *
264  * @return zero on success, a negative value corresponding to an
265  * AVERROR code otherwise
266  */
268 
269  int priv_size; ///< size of private data to allocate for the filter
270 
271  /**
272  * Used by the filter registration system. Must not be touched by any other
273  * code.
274  */
275  struct AVFilter *next;
276 
277  /**
278  * Make the filter instance process a command.
279  *
280  * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
281  * @param arg the argument for the command
282  * @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.
283  * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
284  * time consuming then a filter should treat it like an unsupported command
285  *
286  * @returns >=0 on success otherwise an error code.
287  * AVERROR(ENOSYS) on unsupported commands
288  */
289  int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
290 
291  /**
292  * Filter initialization function, alternative to the init()
293  * callback. Args contains the user-supplied parameters, opaque is
294  * used for providing binary data.
295  */
296  int (*init_opaque)(AVFilterContext *ctx, void *opaque);
297 
298  /**
299  * Filter activation function.
300  *
301  * Called when any processing is needed from the filter, instead of any
302  * filter_frame and request_frame on pads.
303  *
304  * The function must examine inlinks and outlinks and perform a single
305  * step of processing. If there is nothing to do, the function must do
306  * nothing and not return an error. If more steps are or may be
307  * possible, it must use ff_filter_set_ready() to schedule another
308  * activation.
309  */
311 } AVFilter;
312 
313 /**
314  * Process multiple parts of the frame concurrently.
315  */
316 #define AVFILTER_THREAD_SLICE (1 << 0)
317 
318 typedef struct AVFilterInternal AVFilterInternal;
319 
320 /** An instance of a filter */
322  const AVClass *av_class; ///< needed for av_log() and filters common options
323 
324  const AVFilter *filter; ///< the AVFilter of which this is an instance
325 
326  char *name; ///< name of this filter instance
327 
328  AVFilterPad *input_pads; ///< array of input pads
329  AVFilterLink **inputs; ///< array of pointers to input links
330  unsigned nb_inputs; ///< number of input pads
331 
332  AVFilterPad *output_pads; ///< array of output pads
333  AVFilterLink **outputs; ///< array of pointers to output links
334  unsigned nb_outputs; ///< number of output pads
335 
336  void *priv; ///< private data for use by the filter
337 
338  struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
339 
340  /**
341  * Type of multithreading being allowed/used. A combination of
342  * AVFILTER_THREAD_* flags.
343  *
344  * May be set by the caller before initializing the filter to forbid some
345  * or all kinds of multithreading for this filter. The default is allowing
346  * everything.
347  *
348  * When the filter is initialized, this field is combined using bit AND with
349  * AVFilterGraph.thread_type to get the final mask used for determining
350  * allowed threading types. I.e. a threading type needs to be set in both
351  * to be allowed.
352  *
353  * After the filter is initialized, libavfilter sets this field to the
354  * threading type that is actually used (0 for no multithreading).
355  */
357 
358  /**
359  * An opaque struct for libavfilter internal use.
360  */
361  AVFilterInternal *internal;
362 
364 
365  char *enable_str; ///< enable expression string
366  void *enable; ///< parsed expression (AVExpr*)
367  double *var_values; ///< variable values for the enable expression
368  int is_disabled; ///< the enabled state from the last expression evaluation
369 
370  /**
371  * For filters which will create hardware frames, sets the device the
372  * filter should create them in. All other filters will ignore this field:
373  * in particular, a filter which consumes or processes hardware frames will
374  * instead use the hw_frames_ctx field in AVFilterLink to carry the
375  * hardware context information.
376  */
378 
379  /**
380  * Max number of threads allowed in this filter instance.
381  * If <= 0, its value is ignored.
382  * Overrides global number of threads set per filter graph.
383  */
385 
386  /**
387  * Ready status of the filter.
388  * A non-0 value means that the filter needs activating;
389  * a higher value suggests a more urgent activation.
390  */
391  unsigned ready;
392 };
393 
394 /**
395  * A link between two filters. This contains pointers to the source and
396  * destination filters between which this link exists, and the indexes of
397  * the pads involved. In addition, this link also contains the parameters
398  * which have been negotiated and agreed upon between the filter, such as
399  * image dimensions, format, etc.
400  *
401  * Applications must not normally access the link structure directly.
402  * Use the buffersrc and buffersink API instead.
403  * In the future, access to the header may be reserved for filters
404  * implementation.
405  */
406 struct AVFilterLink {
407  AVFilterContext *src; ///< source filter
408  AVFilterPad *srcpad; ///< output pad on the source filter
409 
410  AVFilterContext *dst; ///< dest filter
411  AVFilterPad *dstpad; ///< input pad on the dest filter
412 
413  enum AVMediaType type; ///< filter media type
414 
415  /* These parameters apply only to video */
416  int w; ///< agreed upon image width
417  int h; ///< agreed upon image height
418  AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
419  /* These parameters apply only to audio */
420  uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
421  int sample_rate; ///< samples per second
422 
423  int format; ///< agreed upon media format
424 
425  /**
426  * Define the time base used by the PTS of the frames/samples
427  * which will pass through this link.
428  * During the configuration stage, each filter is supposed to
429  * change only the output timebase, while the timebase of the
430  * input link is assumed to be an unchangeable property.
431  */
433 
434  /*****************************************************************
435  * All fields below this line are not part of the public API. They
436  * may not be used outside of libavfilter and can be changed and
437  * removed at will.
438  * New public fields should be added right above.
439  *****************************************************************
440  */
441  /**
442  * Lists of formats and channel layouts supported by the input and output
443  * filters respectively. These lists are used for negotiating the format
444  * to actually be used, which will be loaded into the format and
445  * channel_layout members, above, when chosen.
446  *
447  */
450 
451  /**
452  * Lists of channel layouts and sample rates used for automatic
453  * negotiation.
454  */
459 
460  /**
461  * Audio only, the destination filter sets this to a non-zero value to
462  * request that buffers with the given number of samples should be sent to
463  * it. AVFilterPad.needs_fifo must also be set on the corresponding input
464  * pad.
465  * Last buffer before EOF will be padded with silence.
466  */
468 
469  /** stage of the initialization of the link properties (dimensions, etc) */
470  enum {
471  AVLINK_UNINIT = 0, ///< not started
472  AVLINK_STARTINIT, ///< started, but incomplete
473  AVLINK_INIT ///< complete
474  } init_state;
475 
476  /**
477  * Graph the filter belongs to.
478  */
480 
481  /**
482  * Current timestamp of the link, as defined by the most recent
483  * frame(s), in link time_base units.
484  */
485  int64_t current_pts;
486 
487  /**
488  * Current timestamp of the link, as defined by the most recent
489  * frame(s), in AV_TIME_BASE units.
490  */
491  int64_t current_pts_us;
492 
493  /**
494  * Index in the age array.
495  */
497 
498  /**
499  * Frame rate of the stream on the link, or 1/0 if unknown or variable;
500  * if left to 0/0, will be automatically copied from the first input
501  * of the source filter if it exists.
502  *
503  * Sources should set it to the best estimation of the real frame rate.
504  * If the source frame rate is unknown or variable, set this to 1/0.
505  * Filters should update it if necessary depending on their function.
506  * Sinks can use it to set a default output frame rate.
507  * It is similar to the r_frame_rate field in AVStream.
508  */
510 
511  /**
512  * Buffer partially filled with samples to achieve a fixed/minimum size.
513  */
515 
516  /**
517  * Size of the partial buffer to allocate.
518  * Must be between min_samples and max_samples.
519  */
521 
522  /**
523  * Minimum number of samples to filter at once. If filter_frame() is
524  * called with fewer samples, it will accumulate them in partial_buf.
525  * This field and the related ones must not be changed after filtering
526  * has started.
527  * If 0, all related fields are ignored.
528  */
530 
531  /**
532  * Maximum number of samples to filter at once. If filter_frame() is
533  * called with more samples, it will split them.
534  */
536 
537  /**
538  * Number of channels.
539  */
540  int channels;
541 
542  /**
543  * Link processing flags.
544  */
545  unsigned flags;
546 
547  /**
548  * Number of past frames sent through the link.
549  */
551 
552  /**
553  * A pointer to a FFFramePool struct.
554  */
555  void *frame_pool;
556 
557  /**
558  * True if a frame is currently wanted on the output of this filter.
559  * Set when ff_request_frame() is called by the output,
560  * cleared when a frame is filtered.
561  */
563 
564  /**
565  * For hwaccel pixel formats, this should be a reference to the
566  * AVHWFramesContext describing the frames.
567  */
569 
570 #ifndef FF_INTERNAL_FIELDS
571 
572  /**
573  * Internal structure members.
574  * The fields below this limit are internal for libavfilter's use
575  * and must in no way be accessed by applications.
576  */
577  char reserved[0xF000];
578 
579 #else /* FF_INTERNAL_FIELDS */
580 
581  /**
582  * Queue of frames waiting to be filtered.
583  */
584  FFFrameQueue fifo;
585 
586  /**
587  * If set, the source filter can not generate a frame as is.
588  * The goal is to avoid repeatedly calling the request_frame() method on
589  * the same link.
590  */
591  int frame_blocked_in;
592 
593  /**
594  * Link input status.
595  * If not zero, all attempts of filter_frame will fail with the
596  * corresponding code.
597  */
598  int status_in;
599 
600  /**
601  * Timestamp of the input status change.
602  */
603  int64_t status_in_pts;
604 
605  /**
606  * Link output status.
607  * If not zero, all attempts of request_frame will fail with the
608  * corresponding code.
609  */
610  int status_out;
611 
612 #endif /* FF_INTERNAL_FIELDS */
613 
614 };
615 
616 /**
617  * Link two filters together.
618  *
619  * @param src the source filter
620  * @param srcpad index of the output pad on the source filter
621  * @param dst the destination filter
622  * @param dstpad index of the input pad on the destination filter
623  * @return zero on success
624  */
625 int avfilter_link(AVFilterContext *src, unsigned srcpad,
626  AVFilterContext *dst, unsigned dstpad);
627 
628 /**
629  * Free the link in *link, and set its pointer to NULL.
630  */
631 void avfilter_link_free(AVFilterLink **link);
632 
633 /**
634  * Get the number of channels of a link.
635  */
637 
638 /**
639  * Set the closed field of a link.
640  * @deprecated applications are not supposed to mess with links, they should
641  * close the sinks.
642  */
644 void avfilter_link_set_closed(AVFilterLink *link, int closed);
645 
646 /**
647  * Negotiate the media format, dimensions, etc of all inputs to a filter.
648  *
649  * @param filter the filter to negotiate the properties for its inputs
650  * @return zero on successful negotiation
651  */
653 
654 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
655 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
656 
657 /**
658  * Make the filter instance process a command.
659  * It is recommended to use avfilter_graph_send_command().
660  */
661 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
662 
663 /** Initialize the filter system. Register all builtin filters. */
664 void avfilter_register_all(void);
665 
666 #if FF_API_OLD_FILTER_REGISTER
667 /** Uninitialize the filter system. Unregister all filters. */
669 void avfilter_uninit(void);
670 #endif
671 
672 /**
673  * Register a filter. This is only needed if you plan to use
674  * avfilter_get_by_name later to lookup the AVFilter structure by name. A
675  * filter can still by instantiated with avfilter_graph_alloc_filter even if it
676  * is not registered.
677  *
678  * @param filter the filter to register
679  * @return 0 if the registration was successful, a negative value
680  * otherwise
681  */
683 
684 /**
685  * Get a filter definition matching the given name.
686  *
687  * @param name the filter name to find
688  * @return the filter definition, if any matching one is registered.
689  * NULL if none found.
690  */
691 #if !FF_API_NOCONST_GET_NAME
692 const
693 #endif
694 AVFilter *avfilter_get_by_name(const char *name);
695 
696 /**
697  * Iterate over all registered filters.
698  * @return If prev is non-NULL, next registered filter after prev or NULL if
699  * prev is the last filter. If prev is NULL, return the first registered filter.
700  */
701 const AVFilter *avfilter_next(const AVFilter *prev);
702 
703 #if FF_API_OLD_FILTER_REGISTER
704 /**
705  * If filter is NULL, returns a pointer to the first registered filter pointer,
706  * if filter is non-NULL, returns the next pointer after filter.
707  * If the returned pointer points to NULL, the last registered filter
708  * was already reached.
709  * @deprecated use avfilter_next()
710  */
712 AVFilter **av_filter_next(AVFilter **filter);
713 #endif
714 
715 #if FF_API_AVFILTER_OPEN
716 /**
717  * Create a filter instance.
718  *
719  * @param filter_ctx put here a pointer to the created filter context
720  * on success, NULL on failure
721  * @param filter the filter to create an instance of
722  * @param inst_name Name to give to the new instance. Can be NULL for none.
723  * @return >= 0 in case of success, a negative error code otherwise
724  * @deprecated use avfilter_graph_alloc_filter() instead
725  */
727 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
728 #endif
729 
730 
731 #if FF_API_AVFILTER_INIT_FILTER
732 /**
733  * Initialize a filter.
734  *
735  * @param filter the filter to initialize
736  * @param args A string of parameters to use when initializing the filter.
737  * The format and meaning of this string varies by filter.
738  * @param opaque Any extra non-string data needed by the filter. The meaning
739  * of this parameter varies by filter.
740  * @return zero on success
741  */
743 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
744 #endif
745 
746 /**
747  * Initialize a filter with the supplied parameters.
748  *
749  * @param ctx uninitialized filter context to initialize
750  * @param args Options to initialize the filter with. This must be a
751  * ':'-separated list of options in the 'key=value' form.
752  * May be NULL if the options have been set directly using the
753  * AVOptions API or there are no options that need to be set.
754  * @return 0 on success, a negative AVERROR on failure
755  */
756 int avfilter_init_str(AVFilterContext *ctx, const char *args);
757 
758 /**
759  * Initialize a filter with the supplied dictionary of options.
760  *
761  * @param ctx uninitialized filter context to initialize
762  * @param options An AVDictionary filled with options for this filter. On
763  * return this parameter will be destroyed and replaced with
764  * a dict containing options that were not found. This dictionary
765  * must be freed by the caller.
766  * May be NULL, then this function is equivalent to
767  * avfilter_init_str() with the second parameter set to NULL.
768  * @return 0 on success, a negative AVERROR on failure
769  *
770  * @note This function and avfilter_init_str() do essentially the same thing,
771  * the difference is in manner in which the options are passed. It is up to the
772  * calling code to choose whichever is more preferable. The two functions also
773  * behave differently when some of the provided options are not declared as
774  * supported by the filter. In such a case, avfilter_init_str() will fail, but
775  * this function will leave those extra options in the options AVDictionary and
776  * continue as usual.
777  */
779 
780 /**
781  * Free a filter context. This will also remove the filter from its
782  * filtergraph's list of filters.
783  *
784  * @param filter the filter to free
785  */
787 
788 /**
789  * Insert a filter in the middle of an existing link.
790  *
791  * @param link the link into which the filter should be inserted
792  * @param filt the filter to be inserted
793  * @param filt_srcpad_idx the input pad on the filter to connect
794  * @param filt_dstpad_idx the output pad on the filter to connect
795  * @return zero on success
796  */
798  unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
799 
800 /**
801  * @return AVClass for AVFilterContext.
802  *
803  * @see av_opt_find().
804  */
805 const AVClass *avfilter_get_class(void);
806 
808 
809 /**
810  * A function pointer passed to the @ref AVFilterGraph.execute callback to be
811  * executed multiple times, possibly in parallel.
812  *
813  * @param ctx the filter context the job belongs to
814  * @param arg an opaque parameter passed through from @ref
815  * AVFilterGraph.execute
816  * @param jobnr the index of the job being executed
817  * @param nb_jobs the total number of jobs
818  *
819  * @return 0 on success, a negative AVERROR on error
820  */
821 typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
822 
823 /**
824  * A function executing multiple jobs, possibly in parallel.
825  *
826  * @param ctx the filter context to which the jobs belong
827  * @param func the function to be called multiple times
828  * @param arg the argument to be passed to func
829  * @param ret a nb_jobs-sized array to be filled with return values from each
830  * invocation of func
831  * @param nb_jobs the number of jobs to execute
832  *
833  * @return 0 on success, a negative AVERROR on error
834  */
836  void *arg, int *ret, int nb_jobs);
837 
838 typedef struct AVFilterGraph {
841  unsigned nb_filters;
842 
843  char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
844  char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
845 
846  /**
847  * Type of multithreading allowed for filters in this graph. A combination
848  * of AVFILTER_THREAD_* flags.
849  *
850  * May be set by the caller at any point, the setting will apply to all
851  * filters initialized after that. The default is allowing everything.
852  *
853  * When a filter in this graph is initialized, this field is combined using
854  * bit AND with AVFilterContext.thread_type to get the final mask used for
855  * determining allowed threading types. I.e. a threading type needs to be
856  * set in both to be allowed.
857  */
859 
860  /**
861  * Maximum number of threads used by filters in this graph. May be set by
862  * the caller before adding any filters to the filtergraph. Zero (the
863  * default) means that the number of threads is determined automatically.
864  */
866 
867  /**
868  * Opaque object for libavfilter internal use.
869  */
871 
872  /**
873  * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
874  * be used from callbacks like @ref AVFilterGraph.execute.
875  * Libavfilter will not touch this field in any way.
876  */
877  void *opaque;
878 
879  /**
880  * This callback may be set by the caller immediately after allocating the
881  * graph and before adding any filters to it, to provide a custom
882  * multithreading implementation.
883  *
884  * If set, filters with slice threading capability will call this callback
885  * to execute multiple jobs in parallel.
886  *
887  * If this field is left unset, libavfilter will use its internal
888  * implementation, which may or may not be multithreaded depending on the
889  * platform and build options.
890  */
892 
893  char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
894 
895  /**
896  * Private fields
897  *
898  * The following fields are for internal use only.
899  * Their type, offset, number and semantic can change without notice.
900  */
901 
904 
906 } AVFilterGraph;
907 
908 /**
909  * Allocate a filter graph.
910  *
911  * @return the allocated filter graph on success or NULL.
912  */
914 
915 /**
916  * Create a new filter instance in a filter graph.
917  *
918  * @param graph graph in which the new filter will be used
919  * @param filter the filter to create an instance of
920  * @param name Name to give to the new instance (will be copied to
921  * AVFilterContext.name). This may be used by the caller to identify
922  * different filters, libavfilter itself assigns no semantics to
923  * this parameter. May be NULL.
924  *
925  * @return the context of the newly created filter instance (note that it is
926  * also retrievable directly through AVFilterGraph.filters or with
927  * avfilter_graph_get_filter()) on success or NULL on failure.
928  */
930  const AVFilter *filter,
931  const char *name);
932 
933 /**
934  * Get a filter instance identified by instance name from graph.
935  *
936  * @param graph filter graph to search through.
937  * @param name filter instance name (should be unique in the graph).
938  * @return the pointer to the found filter instance or NULL if it
939  * cannot be found.
940  */
942 
943 #if FF_API_AVFILTER_OPEN
944 /**
945  * Add an existing filter instance to a filter graph.
946  *
947  * @param graphctx the filter graph
948  * @param filter the filter to be added
949  *
950  * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a
951  * filter graph
952  */
954 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
955 #endif
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 parameters args and opaque.
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  */
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:840
void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags)
Enable or disable automatic format conversion inside the graph.
double * var_values
variable values for the enable expression
Definition: avfilter.h:367
int sink_links_count
Definition: avfilter.h:903
This structure describes decoded (raw) audio or video data.
Definition: frame.h:190
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:858
void avfilter_free(AVFilterContext *filter)
Free a filter context.
Definition: avfilter.c:791
AVFilterGraph * avfilter_graph_alloc(void)
Allocate a filter graph.
Definition: avfiltergraph.c:80
int(* init)(AVFilterContext *ctx)
Filter initialization function.
Definition: avfilter.h:218
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.
Definition: graphparser.c:187
struct AVFilterInOut * next
next input/input in the list, NULL if this is the last
Definition: avfilter.h:1024
Queue of AVFrame pointers.
Definition: framequeue.h:53
enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx)
Get the type of an AVFilterPad.
Definition: avfilter.c:1086
Libavfilter version macros.
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:377
Convenience header that includes libavutil's core.
int(* query_formats)(AVFilterContext *)
Query formats supported by the filter on its inputs and outputs.
Definition: avfilter.h:267
#define src
Definition: vp8dsp.c:254
int thread_type
Type of multithreading being allowed/used.
Definition: avfilter.h:356
int is_disabled
the enabled state from the last expression evaluation
Definition: avfilter.h:368
Macro definitions for various function/variable attributes.
int nb_threads
Max number of threads allowed in this filter instance.
Definition: avfilter.h:384
char * scale_sws_opts
sws options to use for the auto-inserted scale filters
Definition: avfilter.h:843
struct AVFilterGraph * graph
filtergraph this filter belongs to
Definition: avfilter.h:338
int priv_size
size of private data to allocate for the filter
Definition: avfilter.h:269
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:329
char * name
name of this filter instance
Definition: avfilter.h:326
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:891
int avfilter_link(AVFilterContext *src, unsigned srcpad, AVFilterContext *dst, unsigned dstpad)
Link two filters together.
Definition: avfilter.c:135
AVFilterPad * output_pads
array of output pads
Definition: avfilter.h:332
const char * avfilter_license(void)
Return the libavfilter license.
Definition: avfilter.c:88
unsigned ready
Ready status of the filter.
Definition: avfilter.h:391
static void filter(int16_t *output, ptrdiff_t out_stride, int16_t *low, ptrdiff_t low_stride, int16_t *high, ptrdiff_t high_stride, int len, uint8_t clip)
Definition: cfhd.c:80
int flags
A combination of AVFILTER_FLAG_*.
Definition: avfilter.h:187
void avfilter_register_all(void)
Initialize the filter system.
Definition: allfilters.c:40
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.
char * resample_lavr_opts
libavresample options to use for the auto-inserted resample filters
Definition: avfilter.h:844
int nb_threads
Maximum number of threads used by filters in this graph.
Definition: avfilter.h:865
int avfilter_config_links(AVFilterContext *filter)
Negotiate the media format, dimensions, etc of all inputs to a filter.
Definition: avfilter.c:275
static int flags
Definition: log.c:57
const AVFilter * avfilter_next(const AVFilter *prev)
Iterate over all registered filters.
Definition: avfilter.c:596
AVFilterContext * avfilter_graph_get_filter(AVFilterGraph *graph, const char *name)
Get a filter instance identified by instance name from graph.
void(* uninit)(AVFilterContext *ctx)
Filter uninitialization function.
Definition: avfilter.h:243
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:289
int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters, AVFilterInOut **inputs, AVFilterInOut **outputs)
Add a graph described by a string to a graph.
Definition: graphparser.c:391
const OptionDef options[]
Definition: ffserver.c:3952
all automatic conversions disabled
Definition: avfilter.h:986
A filter pad used for either input or output.
Definition: internal.h:54
AVFilterPad * input_pads
array of input pads
Definition: avfilter.h:328
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:821
int avfilter_link_get_channels(AVFilterLink *link)
Get the number of channels of a link.
Definition: avfilter.c:186
const AVClass * av_class
Definition: avfilter.h:839
unsigned nb_outputs
number of output pads
Definition: avfilter.h:334
unsigned avfilter_version(void)
Return the LIBAVFILTER_VERSION_INT constant.
Definition: avfilter.c:77
void * priv
private data for use by the filter
Definition: avfilter.h:336
char * enable_str
enable expression string
Definition: avfilter.h:365
const char * arg
Definition: jacosubdec.c:66
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:231
static FilteringContext * filter_ctx
Definition: transcoding.c:46
AVFilterLink ** sink_links
Private fields.
Definition: avfilter.h:902
reference-counted frame API
const AVFilter * avfilter_get_by_name(const char *name)
Get a filter definition matching the given name.
Definition: avfilter.c:566
attribute_deprecated void avfilter_link_set_closed(AVFilterLink *link, int closed)
Set the closed field of a link.
Definition: avfilter.c:233
unsigned nb_inputs
number of input pads
Definition: avfilter.h:330
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
AVFormatContext * ctx
Definition: movenc.c:48
all automatic conversions enabled
Definition: avfilter.h:985
static const AVFilterPad outputs[]
Definition: af_afftfilt.c:386
int(* init_opaque)(AVFilterContext *ctx, void *opaque)
Filter initialization function, alternative to the init() callback.
Definition: avfilter.h:296
AVFilterContext * filter_ctx
filter context associated to this input/output
Definition: avfilter.h:1018
A list of supported channel layouts.
Definition: formats.h:85
int avfilter_init_str(AVFilterContext *ctx, const char *args)
Initialize a filter with the supplied parameters.
Definition: avfilter.c:962
const AVFilterPad * inputs
List of inputs, terminated by a zeroed element.
Definition: avfilter.h:164
const AVClass * avfilter_get_class(void)
Definition: avfilter.c:1649
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.
Definition: avfilter.c:238
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:835
const AVClass * priv_class
A class for the private data, used to declare filter private AVOptions.
Definition: avfilter.h:182
static const AVFilterPad inputs[]
Definition: af_afftfilt.c:376
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.
Definition: avfilter.c:539
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.
Definition: graphparser.c:459
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
int pad_idx
index of the filt_ctx pad to use for linking
Definition: avfilter.h:1021
Rational number (pair of numerator and denominator).
Definition: rational.h:58
struct AVFilter * next
Used by the filter registration system.
Definition: avfilter.h:275
int(* func)(AVBPrint *dst, const char *in, const char *arg)
Definition: jacosubdec.c:67
AVMediaType
Definition: avutil.h:199
refcounted data buffer API
const char * name
Filter name.
Definition: avfilter.h:148
unsigned nb_filters
Definition: avfilter.h:841
const char * avfilter_configuration(void)
Return the libavfilter build-time configuration.
Definition: avfilter.c:83
const char * avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx)
Get the name of an AVFilterPad.
Definition: avfilter.c:1081
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:333
char * name
unique name for this input/output in the list
Definition: avfilter.h:1015
static const int8_t filt[NUMTAPS]
Definition: af_earwax.c:39
#define attribute_deprecated
Definition: attributes.h:94
int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options)
Initialize a filter with the supplied dictionary of options.
Definition: avfilter.c:925
A reference to a data buffer.
Definition: buffer.h:81
void * opaque
Opaque user data.
Definition: avfilter.h:877
int
AVFilterInOut * avfilter_inout_alloc(void)
Allocate a single AVFilterInOut entry.
Definition: graphparser.c:182
Utilties for rational number calculation.
struct AVFilterCommand * command_queue
Definition: avfilter.h:363
char * avfilter_graph_dump(AVFilterGraph *graph, const char *options)
Dump a graph into a human-readable string representation.
Definition: graphdump.c:155
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.
char * aresample_swr_opts
swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions ...
Definition: avfilter.h:893
pixel format definitions
const char * description
A description of the filter.
Definition: avfilter.h:155
int avfilter_register(AVFilter *filter)
Register a filter.
Definition: avfilter.c:580
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:366
const AVClass * av_class
needed for av_log() and filters common options
Definition: avfilter.h:322
static const struct PPFilter filters[]
Definition: postprocess.c:137
A list of supported formats for one end of a filter link.
Definition: formats.h:64
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.
Definition: graphparser.c:522
An instance of a filter.
Definition: avfilter.h:321
int avfilter_pad_count(const AVFilterPad *pads)
Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
Definition: avfilter.c:612
const AVFilterPad * outputs
List of outputs, terminated by a zeroed element.
Definition: avfilter.h:172
int(* activate)(AVFilterContext *ctx)
Filter activation function.
Definition: avfilter.h:310
void avfilter_link_free(AVFilterLink **link)
Free the link in *link, and set its pointer to NULL.
Definition: avfilter.c:174
const AVFilter * filter
the AVFilter of which this is an instance
Definition: avfilter.h:324
unsigned disable_auto_convert
Definition: avfilter.h:905
const char * name
Definition: opengl_enc.c:103