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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 - graph-based frame editing library
33  * @{
34  */
35 
36 #include <stddef.h>
37 
38 #include "libavutil/attributes.h"
39 #include "libavutil/avutil.h"
40 #include "libavutil/dict.h"
41 #include "libavutil/frame.h"
42 #include "libavutil/log.h"
43 #include "libavutil/samplefmt.h"
44 #include "libavutil/pixfmt.h"
45 #include "libavutil/rational.h"
46 
47 #include "libavfilter/version.h"
48 
49 /**
50  * Return the LIBAVFILTER_VERSION_INT constant.
51  */
52 unsigned avfilter_version(void);
53 
54 /**
55  * Return the libavfilter build-time configuration.
56  */
57 const char *avfilter_configuration(void);
58 
59 /**
60  * Return the libavfilter license.
61  */
62 const char *avfilter_license(void);
63 
64 typedef struct AVFilterContext AVFilterContext;
65 typedef struct AVFilterLink AVFilterLink;
66 typedef struct AVFilterPad AVFilterPad;
67 typedef struct AVFilterFormats AVFilterFormats;
68 
69 /**
70  * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
71  * AVFilter.inputs/outputs).
72  */
73 int avfilter_pad_count(const AVFilterPad *pads);
74 
75 /**
76  * Get the name of an AVFilterPad.
77  *
78  * @param pads an array of AVFilterPads
79  * @param pad_idx index of the pad in the array it; is the caller's
80  * responsibility to ensure the index is valid
81  *
82  * @return name of the pad_idx'th pad in pads
83  */
84 const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
85 
86 /**
87  * Get the type of an AVFilterPad.
88  *
89  * @param pads an array of AVFilterPads
90  * @param pad_idx index of the pad in the array; it is the caller's
91  * responsibility to ensure the index is valid
92  *
93  * @return type of the pad_idx'th pad in pads
94  */
95 enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
96 
97 /**
98  * The number of the filter inputs is not determined just by AVFilter.inputs.
99  * The filter might add additional inputs during initialization depending on the
100  * options supplied to it.
101  */
102 #define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
103 /**
104  * The number of the filter outputs is not determined just by AVFilter.outputs.
105  * The filter might add additional outputs during initialization depending on
106  * the options supplied to it.
107  */
108 #define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
109 /**
110  * The filter supports multithreading by splitting frames into multiple parts
111  * and processing them concurrently.
112  */
113 #define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
114 /**
115  * Some filters support a generic "enable" expression option that can be used
116  * to enable or disable a filter in the timeline. Filters supporting this
117  * option have this flag set. When the enable expression is false, the default
118  * no-op filter_frame() function is called in place of the filter_frame()
119  * callback defined on each input pad, thus the frame is passed unchanged to
120  * the next filters.
121  */
122 #define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16)
123 /**
124  * Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will
125  * have its filter_frame() callback(s) called as usual even when the enable
126  * expression is false. The filter will disable filtering within the
127  * filter_frame() callback(s) itself, for example executing code depending on
128  * the AVFilterContext->is_disabled value.
129  */
130 #define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)
131 /**
132  * Handy mask to test whether the filter supports or no the timeline feature
133  * (internally or generically).
134  */
135 #define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)
136 
137 /**
138  * Filter definition. This defines the pads a filter contains, and all the
139  * callback functions used to interact with the filter.
140  */
141 typedef struct AVFilter {
142  /**
143  * Filter name. Must be non-NULL and unique among filters.
144  */
145  const char *name;
146 
147  /**
148  * A description of the filter. May be NULL.
149  *
150  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
151  */
152  const char *description;
153 
154  /**
155  * List of inputs, terminated by a zeroed element.
156  *
157  * NULL if there are no (static) inputs. Instances of filters with
158  * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in
159  * this list.
160  */
162  /**
163  * List of outputs, terminated by a zeroed element.
164  *
165  * NULL if there are no (static) outputs. Instances of filters with
166  * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in
167  * this list.
168  */
170 
171  /**
172  * A class for the private data, used to declare filter private AVOptions.
173  * This field is NULL for filters that do not declare any options.
174  *
175  * If this field is non-NULL, the first member of the filter private data
176  * must be a pointer to AVClass, which will be set by libavfilter generic
177  * code to this class.
178  */
180 
181  /**
182  * A combination of AVFILTER_FLAG_*
183  */
184  int flags;
185 
186  /*****************************************************************
187  * All fields below this line are not part of the public API. They
188  * may not be used outside of libavfilter and can be changed and
189  * removed at will.
190  * New public fields should be added right above.
191  *****************************************************************
192  */
193 
194  /**
195  * Filter initialization function.
196  *
197  * This callback will be called only once during the filter lifetime, after
198  * all the options have been set, but before links between filters are
199  * established and format negotiation is done.
200  *
201  * Basic filter initialization should be done here. Filters with dynamic
202  * inputs and/or outputs should create those inputs/outputs here based on
203  * provided options. No more changes to this filter's inputs/outputs can be
204  * done after this callback.
205  *
206  * This callback must not assume that the filter links exist or frame
207  * parameters are known.
208  *
209  * @ref AVFilter.uninit "uninit" is guaranteed to be called even if
210  * initialization fails, so this callback does not have to clean up on
211  * failure.
212  *
213  * @return 0 on success, a negative AVERROR on failure
214  */
216 
217  /**
218  * Should be set instead of @ref AVFilter.init "init" by the filters that
219  * want to pass a dictionary of AVOptions to nested contexts that are
220  * allocated during init.
221  *
222  * On return, the options dict should be freed and replaced with one that
223  * contains all the options which could not be processed by this filter (or
224  * with NULL if all the options were processed).
225  *
226  * Otherwise the semantics is the same as for @ref AVFilter.init "init".
227  */
229 
230  /**
231  * Filter uninitialization function.
232  *
233  * Called only once right before the filter is freed. Should deallocate any
234  * memory held by the filter, release any buffer references, etc. It does
235  * not need to deallocate the AVFilterContext.priv memory itself.
236  *
237  * This callback may be called even if @ref AVFilter.init "init" was not
238  * called or failed, so it must be prepared to handle such a situation.
239  */
241 
242  /**
243  * Query formats supported by the filter on its inputs and outputs.
244  *
245  * This callback is called after the filter is initialized (so the inputs
246  * and outputs are fixed), shortly before the format negotiation. This
247  * callback may be called more than once.
248  *
249  * This callback must set AVFilterLink.out_formats on every input link and
250  * AVFilterLink.in_formats on every output link to a list of pixel/sample
251  * formats that the filter supports on that link. For audio links, this
252  * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" /
253  * @ref AVFilterLink.out_samplerates "out_samplerates" and
254  * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" /
255  * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously.
256  *
257  * This callback may be NULL for filters with one input, in which case
258  * libavfilter assumes that it supports all input formats and preserves
259  * them on output.
260  *
261  * @return zero on success, a negative value corresponding to an
262  * AVERROR code otherwise
263  */
265 
266  int priv_size; ///< size of private data to allocate for the filter
267 
268  /**
269  * Used by the filter registration system. Must not be touched by any other
270  * code.
271  */
272  struct AVFilter *next;
273 
274  /**
275  * Make the filter instance process a command.
276  *
277  * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
278  * @param arg the argument for the command
279  * @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.
280  * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
281  * time consuming then a filter should treat it like an unsupported command
282  *
283  * @returns >=0 on success otherwise an error code.
284  * AVERROR(ENOSYS) on unsupported commands
285  */
286  int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
287 
288  /**
289  * Filter initialization function, alternative to the init()
290  * callback. Args contains the user-supplied parameters, opaque is
291  * used for providing binary data.
292  */
293  int (*init_opaque)(AVFilterContext *ctx, void *opaque);
294 } AVFilter;
295 
296 /**
297  * Process multiple parts of the frame concurrently.
298  */
299 #define AVFILTER_THREAD_SLICE (1 << 0)
300 
301 typedef struct AVFilterInternal AVFilterInternal;
302 
303 /** An instance of a filter */
305  const AVClass *av_class; ///< needed for av_log() and filters common options
306 
307  const AVFilter *filter; ///< the AVFilter of which this is an instance
308 
309  char *name; ///< name of this filter instance
310 
311  AVFilterPad *input_pads; ///< array of input pads
312  AVFilterLink **inputs; ///< array of pointers to input links
313  unsigned nb_inputs; ///< number of input pads
314 
315  AVFilterPad *output_pads; ///< array of output pads
316  AVFilterLink **outputs; ///< array of pointers to output links
317  unsigned nb_outputs; ///< number of output pads
318 
319  void *priv; ///< private data for use by the filter
320 
321  struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
322 
323  /**
324  * Type of multithreading being allowed/used. A combination of
325  * AVFILTER_THREAD_* flags.
326  *
327  * May be set by the caller before initializing the filter to forbid some
328  * or all kinds of multithreading for this filter. The default is allowing
329  * everything.
330  *
331  * When the filter is initialized, this field is combined using bit AND with
332  * AVFilterGraph.thread_type to get the final mask used for determining
333  * allowed threading types. I.e. a threading type needs to be set in both
334  * to be allowed.
335  *
336  * After the filter is initialized, libavfilter sets this field to the
337  * threading type that is actually used (0 for no multithreading).
338  */
340 
341  /**
342  * An opaque struct for libavfilter internal use.
343  */
344  AVFilterInternal *internal;
345 
347 
348  char *enable_str; ///< enable expression string
349  void *enable; ///< parsed expression (AVExpr*)
350  double *var_values; ///< variable values for the enable expression
351  int is_disabled; ///< the enabled state from the last expression evaluation
352 };
353 
354 /**
355  * A link between two filters. This contains pointers to the source and
356  * destination filters between which this link exists, and the indexes of
357  * the pads involved. In addition, this link also contains the parameters
358  * which have been negotiated and agreed upon between the filter, such as
359  * image dimensions, format, etc.
360  */
361 struct AVFilterLink {
362  AVFilterContext *src; ///< source filter
363  AVFilterPad *srcpad; ///< output pad on the source filter
364 
365  AVFilterContext *dst; ///< dest filter
366  AVFilterPad *dstpad; ///< input pad on the dest filter
367 
368  enum AVMediaType type; ///< filter media type
369 
370  /* These parameters apply only to video */
371  int w; ///< agreed upon image width
372  int h; ///< agreed upon image height
373  AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
374  /* These parameters apply only to audio */
375  uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
376  int sample_rate; ///< samples per second
377 
378  int format; ///< agreed upon media format
379 
380  /**
381  * Define the time base used by the PTS of the frames/samples
382  * which will pass through this link.
383  * During the configuration stage, each filter is supposed to
384  * change only the output timebase, while the timebase of the
385  * input link is assumed to be an unchangeable property.
386  */
388 
389  /*****************************************************************
390  * All fields below this line are not part of the public API. They
391  * may not be used outside of libavfilter and can be changed and
392  * removed at will.
393  * New public fields should be added right above.
394  *****************************************************************
395  */
396  /**
397  * Lists of formats and channel layouts supported by the input and output
398  * filters respectively. These lists are used for negotiating the format
399  * to actually be used, which will be loaded into the format and
400  * channel_layout members, above, when chosen.
401  *
402  */
405 
406  /**
407  * Lists of channel layouts and sample rates used for automatic
408  * negotiation.
409  */
414 
415  /**
416  * Audio only, the destination filter sets this to a non-zero value to
417  * request that buffers with the given number of samples should be sent to
418  * it. AVFilterPad.needs_fifo must also be set on the corresponding input
419  * pad.
420  * Last buffer before EOF will be padded with silence.
421  */
423 
424  /** stage of the initialization of the link properties (dimensions, etc) */
425  enum {
426  AVLINK_UNINIT = 0, ///< not started
427  AVLINK_STARTINIT, ///< started, but incomplete
428  AVLINK_INIT ///< complete
429  } init_state;
430 
431  /**
432  * Graph the filter belongs to.
433  */
435 
436  /**
437  * Current timestamp of the link, as defined by the most recent
438  * frame(s), in link time_base units.
439  */
440  int64_t current_pts;
441 
442  /**
443  * Current timestamp of the link, as defined by the most recent
444  * frame(s), in AV_TIME_BASE units.
445  */
446  int64_t current_pts_us;
447 
448  /**
449  * Index in the age array.
450  */
452 
453  /**
454  * Frame rate of the stream on the link, or 1/0 if unknown or variable;
455  * if left to 0/0, will be automatically copied from the first input
456  * of the source filter if it exists.
457  *
458  * Sources should set it to the best estimation of the real frame rate.
459  * If the source frame rate is unknown or variable, set this to 1/0.
460  * Filters should update it if necessary depending on their function.
461  * Sinks can use it to set a default output frame rate.
462  * It is similar to the r_frame_rate field in AVStream.
463  */
465 
466  /**
467  * Buffer partially filled with samples to achieve a fixed/minimum size.
468  */
470 
471  /**
472  * Size of the partial buffer to allocate.
473  * Must be between min_samples and max_samples.
474  */
476 
477  /**
478  * Minimum number of samples to filter at once. If filter_frame() is
479  * called with fewer samples, it will accumulate them in partial_buf.
480  * This field and the related ones must not be changed after filtering
481  * has started.
482  * If 0, all related fields are ignored.
483  */
485 
486  /**
487  * Maximum number of samples to filter at once. If filter_frame() is
488  * called with more samples, it will split them.
489  */
491 
492  /**
493  * Link status.
494  * If not zero, all attempts of filter_frame or request_frame
495  * will fail with the corresponding code, and if necessary the reference
496  * will be destroyed.
497  * If request_frame returns an error, the status is set on the
498  * corresponding link.
499  * It can be set also be set by either the source or the destination
500  * filter.
501  */
502  int status;
503 
504  /**
505  * Number of channels.
506  */
507  int channels;
508 
509  /**
510  * Link processing flags.
511  */
512  unsigned flags;
513 
514  /**
515  * Number of past frames sent through the link.
516  */
517  int64_t frame_count;
518 
519  /**
520  * A pointer to a FFVideoFramePool struct.
521  */
523 
524  /**
525  * True if a frame is currently wanted on the input of this filter.
526  * Set when ff_request_frame() is called by the output,
527  * cleared when the request is handled or forwarded.
528  */
530 
531  /**
532  * True if a frame is currently wanted on the output of this filter.
533  * Set when ff_request_frame() is called by the output,
534  * cleared when a frame is filtered.
535  */
537 };
538 
539 /**
540  * Link two filters together.
541  *
542  * @param src the source filter
543  * @param srcpad index of the output pad on the source filter
544  * @param dst the destination filter
545  * @param dstpad index of the input pad on the destination filter
546  * @return zero on success
547  */
548 int avfilter_link(AVFilterContext *src, unsigned srcpad,
549  AVFilterContext *dst, unsigned dstpad);
550 
551 /**
552  * Free the link in *link, and set its pointer to NULL.
553  */
554 void avfilter_link_free(AVFilterLink **link);
555 
556 /**
557  * Get the number of channels of a link.
558  */
560 
561 /**
562  * Set the closed field of a link.
563  * @deprecated applications are not supposed to mess with links, they should
564  * close the sinks.
565  */
567 void avfilter_link_set_closed(AVFilterLink *link, int closed);
568 
569 /**
570  * Negotiate the media format, dimensions, etc of all inputs to a filter.
571  *
572  * @param filter the filter to negotiate the properties for its inputs
573  * @return zero on successful negotiation
574  */
576 
577 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
578 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
579 
580 /**
581  * Make the filter instance process a command.
582  * It is recommended to use avfilter_graph_send_command().
583  */
584 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
585 
586 /** Initialize the filter system. Register all builtin filters. */
587 void avfilter_register_all(void);
588 
589 #if FF_API_OLD_FILTER_REGISTER
590 /** Uninitialize the filter system. Unregister all filters. */
592 void avfilter_uninit(void);
593 #endif
594 
595 /**
596  * Register a filter. This is only needed if you plan to use
597  * avfilter_get_by_name later to lookup the AVFilter structure by name. A
598  * filter can still by instantiated with avfilter_graph_alloc_filter even if it
599  * is not registered.
600  *
601  * @param filter the filter to register
602  * @return 0 if the registration was successful, a negative value
603  * otherwise
604  */
606 
607 /**
608  * Get a filter definition matching the given name.
609  *
610  * @param name the filter name to find
611  * @return the filter definition, if any matching one is registered.
612  * NULL if none found.
613  */
614 #if !FF_API_NOCONST_GET_NAME
615 const
616 #endif
617 AVFilter *avfilter_get_by_name(const char *name);
618 
619 /**
620  * Iterate over all registered filters.
621  * @return If prev is non-NULL, next registered filter after prev or NULL if
622  * prev is the last filter. If prev is NULL, return the first registered filter.
623  */
624 const AVFilter *avfilter_next(const AVFilter *prev);
625 
626 #if FF_API_OLD_FILTER_REGISTER
627 /**
628  * If filter is NULL, returns a pointer to the first registered filter pointer,
629  * if filter is non-NULL, returns the next pointer after filter.
630  * If the returned pointer points to NULL, the last registered filter
631  * was already reached.
632  * @deprecated use avfilter_next()
633  */
635 AVFilter **av_filter_next(AVFilter **filter);
636 #endif
637 
638 #if FF_API_AVFILTER_OPEN
639 /**
640  * Create a filter instance.
641  *
642  * @param filter_ctx put here a pointer to the created filter context
643  * on success, NULL on failure
644  * @param filter the filter to create an instance of
645  * @param inst_name Name to give to the new instance. Can be NULL for none.
646  * @return >= 0 in case of success, a negative error code otherwise
647  * @deprecated use avfilter_graph_alloc_filter() instead
648  */
650 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
651 #endif
652 
653 
654 #if FF_API_AVFILTER_INIT_FILTER
655 /**
656  * Initialize a filter.
657  *
658  * @param filter the filter to initialize
659  * @param args A string of parameters to use when initializing the filter.
660  * The format and meaning of this string varies by filter.
661  * @param opaque Any extra non-string data needed by the filter. The meaning
662  * of this parameter varies by filter.
663  * @return zero on success
664  */
666 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
667 #endif
668 
669 /**
670  * Initialize a filter with the supplied parameters.
671  *
672  * @param ctx uninitialized filter context to initialize
673  * @param args Options to initialize the filter with. This must be a
674  * ':'-separated list of options in the 'key=value' form.
675  * May be NULL if the options have been set directly using the
676  * AVOptions API or there are no options that need to be set.
677  * @return 0 on success, a negative AVERROR on failure
678  */
679 int avfilter_init_str(AVFilterContext *ctx, const char *args);
680 
681 /**
682  * Initialize a filter with the supplied dictionary of options.
683  *
684  * @param ctx uninitialized filter context to initialize
685  * @param options An AVDictionary filled with options for this filter. On
686  * return this parameter will be destroyed and replaced with
687  * a dict containing options that were not found. This dictionary
688  * must be freed by the caller.
689  * May be NULL, then this function is equivalent to
690  * avfilter_init_str() with the second parameter set to NULL.
691  * @return 0 on success, a negative AVERROR on failure
692  *
693  * @note This function and avfilter_init_str() do essentially the same thing,
694  * the difference is in manner in which the options are passed. It is up to the
695  * calling code to choose whichever is more preferable. The two functions also
696  * behave differently when some of the provided options are not declared as
697  * supported by the filter. In such a case, avfilter_init_str() will fail, but
698  * this function will leave those extra options in the options AVDictionary and
699  * continue as usual.
700  */
702 
703 /**
704  * Free a filter context. This will also remove the filter from its
705  * filtergraph's list of filters.
706  *
707  * @param filter the filter to free
708  */
710 
711 /**
712  * Insert a filter in the middle of an existing link.
713  *
714  * @param link the link into which the filter should be inserted
715  * @param filt the filter to be inserted
716  * @param filt_srcpad_idx the input pad on the filter to connect
717  * @param filt_dstpad_idx the output pad on the filter to connect
718  * @return zero on success
719  */
721  unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
722 
723 /**
724  * @return AVClass for AVFilterContext.
725  *
726  * @see av_opt_find().
727  */
728 const AVClass *avfilter_get_class(void);
729 
731 
732 /**
733  * A function pointer passed to the @ref AVFilterGraph.execute callback to be
734  * executed multiple times, possibly in parallel.
735  *
736  * @param ctx the filter context the job belongs to
737  * @param arg an opaque parameter passed through from @ref
738  * AVFilterGraph.execute
739  * @param jobnr the index of the job being executed
740  * @param nb_jobs the total number of jobs
741  *
742  * @return 0 on success, a negative AVERROR on error
743  */
744 typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
745 
746 /**
747  * A function executing multiple jobs, possibly in parallel.
748  *
749  * @param ctx the filter context to which the jobs belong
750  * @param func the function to be called multiple times
751  * @param arg the argument to be passed to func
752  * @param ret a nb_jobs-sized array to be filled with return values from each
753  * invocation of func
754  * @param nb_jobs the number of jobs to execute
755  *
756  * @return 0 on success, a negative AVERROR on error
757  */
759  void *arg, int *ret, int nb_jobs);
760 
761 typedef struct AVFilterGraph {
764  unsigned nb_filters;
765 
766  char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
767  char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
768 
769  /**
770  * Type of multithreading allowed for filters in this graph. A combination
771  * of AVFILTER_THREAD_* flags.
772  *
773  * May be set by the caller at any point, the setting will apply to all
774  * filters initialized after that. The default is allowing everything.
775  *
776  * When a filter in this graph is initialized, this field is combined using
777  * bit AND with AVFilterContext.thread_type to get the final mask used for
778  * determining allowed threading types. I.e. a threading type needs to be
779  * set in both to be allowed.
780  */
782 
783  /**
784  * Maximum number of threads used by filters in this graph. May be set by
785  * the caller before adding any filters to the filtergraph. Zero (the
786  * default) means that the number of threads is determined automatically.
787  */
789 
790  /**
791  * Opaque object for libavfilter internal use.
792  */
794 
795  /**
796  * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
797  * be used from callbacks like @ref AVFilterGraph.execute.
798  * Libavfilter will not touch this field in any way.
799  */
800  void *opaque;
801 
802  /**
803  * This callback may be set by the caller immediately after allocating the
804  * graph and before adding any filters to it, to provide a custom
805  * multithreading implementation.
806  *
807  * If set, filters with slice threading capability will call this callback
808  * to execute multiple jobs in parallel.
809  *
810  * If this field is left unset, libavfilter will use its internal
811  * implementation, which may or may not be multithreaded depending on the
812  * platform and build options.
813  */
815 
816  char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
817 
818  /**
819  * Private fields
820  *
821  * The following fields are for internal use only.
822  * Their type, offset, number and semantic can change without notice.
823  */
824 
827 
829 } AVFilterGraph;
830 
831 /**
832  * Allocate a filter graph.
833  *
834  * @return the allocated filter graph on success or NULL.
835  */
837 
838 /**
839  * Create a new filter instance in a filter graph.
840  *
841  * @param graph graph in which the new filter will be used
842  * @param filter the filter to create an instance of
843  * @param name Name to give to the new instance (will be copied to
844  * AVFilterContext.name). This may be used by the caller to identify
845  * different filters, libavfilter itself assigns no semantics to
846  * this parameter. May be NULL.
847  *
848  * @return the context of the newly created filter instance (note that it is
849  * also retrievable directly through AVFilterGraph.filters or with
850  * avfilter_graph_get_filter()) on success or NULL on failure.
851  */
853  const AVFilter *filter,
854  const char *name);
855 
856 /**
857  * Get a filter instance identified by instance name from graph.
858  *
859  * @param graph filter graph to search through.
860  * @param name filter instance name (should be unique in the graph).
861  * @return the pointer to the found filter instance or NULL if it
862  * cannot be found.
863  */
865 
866 #if FF_API_AVFILTER_OPEN
867 /**
868  * Add an existing filter instance to a filter graph.
869  *
870  * @param graphctx the filter graph
871  * @param filter the filter to be added
872  *
873  * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a
874  * filter graph
875  */
877 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
878 #endif
879 
880 /**
881  * Create and add a filter instance into an existing graph.
882  * The filter instance is created from the filter filt and inited
883  * with the parameters args and opaque.
884  *
885  * In case of success put in *filt_ctx the pointer to the created
886  * filter instance, otherwise set *filt_ctx to NULL.
887  *
888  * @param name the instance name to give to the created filter instance
889  * @param graph_ctx the filter graph
890  * @return a negative AVERROR error code in case of failure, a non
891  * negative value otherwise
892  */
894  const char *name, const char *args, void *opaque,
895  AVFilterGraph *graph_ctx);
896 
897 /**
898  * Enable or disable automatic format conversion inside the graph.
899  *
900  * Note that format conversion can still happen inside explicitly inserted
901  * scale and aresample filters.
902  *
903  * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
904  */
906 
907 enum {
908  AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
909  AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
910 };
911 
912 /**
913  * Check validity and configure all the links and formats in the graph.
914  *
915  * @param graphctx the filter graph
916  * @param log_ctx context used for logging
917  * @return >= 0 in case of success, a negative AVERROR code otherwise
918  */
919 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
920 
921 /**
922  * Free a graph, destroy its links, and set *graph to NULL.
923  * If *graph is NULL, do nothing.
924  */
925 void avfilter_graph_free(AVFilterGraph **graph);
926 
927 /**
928  * A linked-list of the inputs/outputs of the filter chain.
929  *
930  * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
931  * where it is used to communicate open (unlinked) inputs and outputs from and
932  * to the caller.
933  * This struct specifies, per each not connected pad contained in the graph, the
934  * filter context and the pad index required for establishing a link.
935  */
936 typedef struct AVFilterInOut {
937  /** unique name for this input/output in the list */
938  char *name;
939 
940  /** filter context associated to this input/output */
942 
943  /** index of the filt_ctx pad to use for linking */
944  int pad_idx;
945 
946  /** next input/input in the list, NULL if this is the last */
948 } AVFilterInOut;
949 
950 /**
951  * Allocate a single AVFilterInOut entry.
952  * Must be freed with avfilter_inout_free().
953  * @return allocated AVFilterInOut on success, NULL on failure.
954  */
956 
957 /**
958  * Free the supplied list of AVFilterInOut and set *inout to NULL.
959  * If *inout is NULL, do nothing.
960  */
961 void avfilter_inout_free(AVFilterInOut **inout);
962 
963 /**
964  * Add a graph described by a string to a graph.
965  *
966  * @note The caller must provide the lists of inputs and outputs,
967  * which therefore must be known before calling the function.
968  *
969  * @note The inputs parameter describes inputs of the already existing
970  * part of the graph; i.e. from the point of view of the newly created
971  * part, they are outputs. Similarly the outputs parameter describes
972  * outputs of the already existing filters, which are provided as
973  * inputs to the parsed filters.
974  *
975  * @param graph the filter graph where to link the parsed graph context
976  * @param filters string to be parsed
977  * @param inputs linked list to the inputs of the graph
978  * @param outputs linked list to the outputs of the graph
979  * @return zero on success, a negative AVERROR code on error
980  */
981 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
983  void *log_ctx);
984 
985 /**
986  * Add a graph described by a string to a graph.
987  *
988  * In the graph filters description, if the input label of the first
989  * filter is not specified, "in" is assumed; if the output label of
990  * the last filter is not specified, "out" is assumed.
991  *
992  * @param graph the filter graph where to link the parsed graph context
993  * @param filters string to be parsed
994  * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
995  * If non-NULL, *inputs is updated to contain the list of open inputs
996  * after the parsing, should be freed with avfilter_inout_free().
997  * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
998  * If non-NULL, *outputs is updated to contain the list of open outputs
999  * after the parsing, should be freed with avfilter_inout_free().
1000  * @return non negative on success, a negative AVERROR code on error
1001  */
1002 int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters,
1004  void *log_ctx);
1005 
1006 /**
1007  * Add a graph described by a string to a graph.
1008  *
1009  * @param[in] graph the filter graph where to link the parsed graph context
1010  * @param[in] filters string to be parsed
1011  * @param[out] inputs a linked list of all free (unlinked) inputs of the
1012  * parsed graph will be returned here. It is to be freed
1013  * by the caller using avfilter_inout_free().
1014  * @param[out] outputs a linked list of all free (unlinked) outputs of the
1015  * parsed graph will be returned here. It is to be freed by the
1016  * caller using avfilter_inout_free().
1017  * @return zero on success, a negative AVERROR code on error
1018  *
1019  * @note This function returns the inputs and outputs that are left
1020  * unlinked after parsing the graph and the caller then deals with
1021  * them.
1022  * @note This function makes no reference whatsoever to already
1023  * existing parts of the graph and the inputs parameter will on return
1024  * contain inputs of the newly parsed part of the graph. Analogously
1025  * the outputs parameter will contain outputs of the newly created
1026  * filters.
1027  */
1028 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
1031 
1032 /**
1033  * Send a command to one or more filter instances.
1034  *
1035  * @param graph the filter graph
1036  * @param target the filter(s) to which the command should be sent
1037  * "all" sends to all filters
1038  * otherwise it can be a filter or filter instance name
1039  * which will send the command to all matching filters.
1040  * @param cmd the command to send, for handling simplicity all commands must be alphanumeric only
1041  * @param arg the argument for the command
1042  * @param res a buffer with size res_size where the filter(s) can return a response.
1043  *
1044  * @returns >=0 on success otherwise an error code.
1045  * AVERROR(ENOSYS) on unsupported commands
1046  */
1047 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
1048 
1049 /**
1050  * Queue a command for one or more filter instances.
1051  *
1052  * @param graph the filter graph
1053  * @param target the filter(s) to which the command should be sent
1054  * "all" sends to all filters
1055  * otherwise it can be a filter or filter instance name
1056  * which will send the command to all matching filters.
1057  * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
1058  * @param arg the argument for the command
1059  * @param ts time at which the command should be sent to the filter
1060  *
1061  * @note As this executes commands after this function returns, no return code
1062  * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
1063  */
1064 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
1065 
1066 
1067 /**
1068  * Dump a graph into a human-readable string representation.
1069  *
1070  * @param graph the graph to dump
1071  * @param options formatting options; currently ignored
1072  * @return a string, or NULL in case of memory allocation failure;
1073  * the string must be freed using av_free
1074  */
1075 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
1076 
1077 /**
1078  * Request a frame on the oldest sink link.
1079  *
1080  * If the request returns AVERROR_EOF, try the next.
1081  *
1082  * Note that this function is not meant to be the sole scheduling mechanism
1083  * of a filtergraph, only a convenience function to help drain a filtergraph
1084  * in a balanced way under normal circumstances.
1085  *
1086  * Also note that AVERROR_EOF does not mean that frames did not arrive on
1087  * some of the sinks during the process.
1088  * When there are multiple sink links, in case the requested link
1089  * returns an EOF, this may cause a filter to flush pending frames
1090  * which are sent to another sink link, although unrequested.
1091  *
1092  * @return the return value of ff_request_frame(),
1093  * or AVERROR_EOF if all links returned AVERROR_EOF
1094  */
1096 
1097 /**
1098  * @}
1099  */
1100 
1101 #endif /* AVFILTER_AVFILTER_H */
AVFilterContext ** filters
Definition: avfilter.h:763
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:350
int sink_links_count
Definition: avfilter.h:826
This structure describes decoded (raw) audio or video data.
Definition: frame.h:181
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:781
void avfilter_free(AVFilterContext *filter)
Free a filter context.
Definition: avfilter.c:727
AVFormatContext * ctx
Definition: movenc-test.c:48
AVFilterGraph * avfilter_graph_alloc(void)
Allocate a filter graph.
Definition: avfiltergraph.c:76
int(* init)(AVFilterContext *ctx)
Filter initialization function.
Definition: avfilter.h:215
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:947
enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx)
Get the type of an AVFilterPad.
Definition: avfilter.c:1013
Libavfilter version macros.
void avfilter_graph_free(AVFilterGraph **graph)
Free a graph, destroy its links, and set *graph to NULL.
external API header
int(* query_formats)(AVFilterContext *)
Query formats supported by the filter on its inputs and outputs.
Definition: avfilter.h:264
int thread_type
Type of multithreading being allowed/used.
Definition: avfilter.h:339
int is_disabled
the enabled state from the last expression evaluation
Definition: avfilter.h:351
Macro definitions for various function/variable attributes.
char * scale_sws_opts
sws options to use for the auto-inserted scale filters
Definition: avfilter.h:766
struct AVFilterGraph * graph
filtergraph this filter belongs to
Definition: avfilter.h:321
int priv_size
size of private data to allocate for the filter
Definition: avfilter.h:266
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:312
char * name
name of this filter instance
Definition: avfilter.h:309
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:814
int avfilter_link(AVFilterContext *src, unsigned srcpad, AVFilterContext *dst, unsigned dstpad)
Link two filters together.
Definition: avfilter.c:131
AVFilterPad * output_pads
array of output pads
Definition: avfilter.h:315
const char * avfilter_license(void)
Return the libavfilter license.
Definition: avfilter.c:84
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:82
int flags
A combination of AVFILTER_FLAG_*.
Definition: avfilter.h:184
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:767
int nb_threads
Maximum number of threads used by filters in this graph.
Definition: avfilter.h:788
int avfilter_config_links(AVFilterContext *filter)
Negotiate the media format, dimensions, etc of all inputs to a filter.
Definition: avfilter.c:235
const AVFilter * avfilter_next(const AVFilter *prev)
Iterate over all registered filters.
Definition: avfilter.c:536
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:240
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:286
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:3962
A filter pad used for either input or output.
Definition: internal.h:53
AVFilterPad * input_pads
array of input pads
Definition: avfilter.h:311
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:744
int avfilter_link_get_channels(AVFilterLink *link)
Get the number of channels of a link.
Definition: avfilter.c:176
const AVClass * av_class
Definition: avfilter.h:762
unsigned nb_outputs
number of output pads
Definition: avfilter.h:317
unsigned avfilter_version(void)
Return the LIBAVFILTER_VERSION_INT constant.
Definition: avfilter.c:73
void * priv
private data for use by the filter
Definition: avfilter.h:319
char * enable_str
enable expression string
Definition: avfilter.h:348
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:228
static FilteringContext * filter_ctx
Definition: transcoding.c:46
AVFilterLink ** sink_links
Private fields.
Definition: avfilter.h:825
reference-counted frame API
const AVFilter * avfilter_get_by_name(const char *name)
Get a filter definition matching the given name.
Definition: avfilter.c:506
attribute_deprecated void avfilter_link_set_closed(AVFilterLink *link, int closed)
Set the closed field of a link.
Definition: avfilter.c:193
unsigned nb_inputs
number of input pads
Definition: avfilter.h:313
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
static const AVFilterPad outputs[]
Definition: af_afftfilt.c:385
int(* init_opaque)(AVFilterContext *ctx, void *opaque)
Filter initialization function, alternative to the init() callback.
Definition: avfilter.h:293
#define src
Definition: vp9dsp.c:530
AVFilterContext * filter_ctx
filter context associated to this input/output
Definition: avfilter.h:941
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:889
const AVFilterPad * inputs
List of inputs, terminated by a zeroed element.
Definition: avfilter.h:161
const AVClass * avfilter_get_class(void)
Definition: avfilter.c:1213
A linked-list of the inputs/outputs of the filter chain.
Definition: avfilter.h:936
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:198
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:758
const AVClass * priv_class
A class for the private data, used to declare filter private AVOptions.
Definition: avfilter.h:179
static const AVFilterPad inputs[]
Definition: af_afftfilt.c:375
all automatic conversions disabled
Definition: avfilter.h:909
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:479
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:141
int pad_idx
index of the filt_ctx pad to use for linking
Definition: avfilter.h:944
rational number numerator/denominator
Definition: rational.h:43
struct AVFilter * next
Used by the filter registration system.
Definition: avfilter.h:272
int(* func)(AVBPrint *dst, const char *in, const char *arg)
Definition: jacosubdec.c:67
AVMediaType
Definition: avutil.h:191
const char * name
Filter name.
Definition: avfilter.h:145
unsigned nb_filters
Definition: avfilter.h:764
const char * avfilter_configuration(void)
Return the libavfilter build-time configuration.
Definition: avfilter.c:79
const char * avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx)
Get the name of an AVFilterPad.
Definition: avfilter.c:1008
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:316
char * name
unique name for this input/output in the list
Definition: avfilter.h:938
static const int8_t filt[NUMTAPS]
Definition: af_earwax.c:39
static int flags
Definition: cpu.c:47
#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:852
void * opaque
Opaque user data.
Definition: avfilter.h:800
AVFilterInOut * avfilter_inout_alloc(void)
Allocate a single AVFilterInOut entry.
Definition: graphparser.c:182
rational numbers
struct AVFilterCommand * command_queue
Definition: avfilter.h:346
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.
all automatic conversions enabled
Definition: avfilter.h:908
char * aresample_swr_opts
swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions ...
Definition: avfilter.h:816
pixel format definitions
const char * description
A description of the filter.
Definition: avfilter.h:152
int avfilter_register(AVFilter *filter)
Register a filter.
Definition: avfilter.c:520
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:349
const AVClass * av_class
needed for av_log() and filters common options
Definition: avfilter.h:305
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:304
int avfilter_pad_count(const AVFilterPad *pads)
Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
Definition: avfilter.c:552
const AVFilterPad * outputs
List of outputs, terminated by a zeroed element.
Definition: avfilter.h:169
void avfilter_link_free(AVFilterLink **link)
Free the link in *link, and set its pointer to NULL.
Definition: avfilter.c:165
const AVFilter * filter
the AVFilter of which this is an instance
Definition: avfilter.h:307
unsigned disable_auto_convert
Definition: avfilter.h:828
const char * name
Definition: opengl_enc.c:103