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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/buffer.h"
41 #include "libavutil/dict.h"
42 #include "libavutil/frame.h"
43 #include "libavutil/log.h"
44 #include "libavutil/samplefmt.h"
45 #include "libavutil/pixfmt.h"
46 #include "libavutil/rational.h"
47 
48 #include "libavfilter/version.h"
49 
50 /**
51  * Return the LIBAVFILTER_VERSION_INT constant.
52  */
53 unsigned avfilter_version(void);
54 
55 /**
56  * Return the libavfilter build-time configuration.
57  */
58 const char *avfilter_configuration(void);
59 
60 /**
61  * Return the libavfilter license.
62  */
63 const char *avfilter_license(void);
64 
65 typedef struct AVFilterContext AVFilterContext;
66 typedef struct AVFilterLink AVFilterLink;
67 typedef struct AVFilterPad AVFilterPad;
68 typedef struct AVFilterFormats AVFilterFormats;
69 
70 /**
71  * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
72  * AVFilter.inputs/outputs).
73  */
74 int avfilter_pad_count(const AVFilterPad *pads);
75 
76 /**
77  * Get the name of an AVFilterPad.
78  *
79  * @param pads an array of AVFilterPads
80  * @param pad_idx index of the pad in the array it; is the caller's
81  * responsibility to ensure the index is valid
82  *
83  * @return name of the pad_idx'th pad in pads
84  */
85 const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
86 
87 /**
88  * Get the type of an AVFilterPad.
89  *
90  * @param pads an array of AVFilterPads
91  * @param pad_idx index of the pad in the array; it is the caller's
92  * responsibility to ensure the index is valid
93  *
94  * @return type of the pad_idx'th pad in pads
95  */
96 enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
97 
98 /**
99  * The number of the filter inputs is not determined just by AVFilter.inputs.
100  * The filter might add additional inputs during initialization depending on the
101  * options supplied to it.
102  */
103 #define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
104 /**
105  * The number of the filter outputs is not determined just by AVFilter.outputs.
106  * The filter might add additional outputs during initialization depending on
107  * the options supplied to it.
108  */
109 #define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
110 /**
111  * The filter supports multithreading by splitting frames into multiple parts
112  * and processing them concurrently.
113  */
114 #define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
115 /**
116  * Some filters support a generic "enable" expression option that can be used
117  * to enable or disable a filter in the timeline. Filters supporting this
118  * option have this flag set. When the enable expression is false, the default
119  * no-op filter_frame() function is called in place of the filter_frame()
120  * callback defined on each input pad, thus the frame is passed unchanged to
121  * the next filters.
122  */
123 #define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16)
124 /**
125  * Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will
126  * have its filter_frame() callback(s) called as usual even when the enable
127  * expression is false. The filter will disable filtering within the
128  * filter_frame() callback(s) itself, for example executing code depending on
129  * the AVFilterContext->is_disabled value.
130  */
131 #define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)
132 /**
133  * Handy mask to test whether the filter supports or no the timeline feature
134  * (internally or generically).
135  */
136 #define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)
137 
138 /**
139  * Filter definition. This defines the pads a filter contains, and all the
140  * callback functions used to interact with the filter.
141  */
142 typedef struct AVFilter {
143  /**
144  * Filter name. Must be non-NULL and unique among filters.
145  */
146  const char *name;
147 
148  /**
149  * A description of the filter. May be NULL.
150  *
151  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
152  */
153  const char *description;
154 
155  /**
156  * List of inputs, terminated by a zeroed element.
157  *
158  * NULL if there are no (static) inputs. Instances of filters with
159  * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in
160  * this list.
161  */
163  /**
164  * List of outputs, terminated by a zeroed element.
165  *
166  * NULL if there are no (static) outputs. Instances of filters with
167  * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in
168  * this list.
169  */
171 
172  /**
173  * A class for the private data, used to declare filter private AVOptions.
174  * This field is NULL for filters that do not declare any options.
175  *
176  * If this field is non-NULL, the first member of the filter private data
177  * must be a pointer to AVClass, which will be set by libavfilter generic
178  * code to this class.
179  */
181 
182  /**
183  * A combination of AVFILTER_FLAG_*
184  */
185  int flags;
186 
187  /*****************************************************************
188  * All fields below this line are not part of the public API. They
189  * may not be used outside of libavfilter and can be changed and
190  * removed at will.
191  * New public fields should be added right above.
192  *****************************************************************
193  */
194 
195  /**
196  * Filter initialization function.
197  *
198  * This callback will be called only once during the filter lifetime, after
199  * all the options have been set, but before links between filters are
200  * established and format negotiation is done.
201  *
202  * Basic filter initialization should be done here. Filters with dynamic
203  * inputs and/or outputs should create those inputs/outputs here based on
204  * provided options. No more changes to this filter's inputs/outputs can be
205  * done after this callback.
206  *
207  * This callback must not assume that the filter links exist or frame
208  * parameters are known.
209  *
210  * @ref AVFilter.uninit "uninit" is guaranteed to be called even if
211  * initialization fails, so this callback does not have to clean up on
212  * failure.
213  *
214  * @return 0 on success, a negative AVERROR on failure
215  */
217 
218  /**
219  * Should be set instead of @ref AVFilter.init "init" by the filters that
220  * want to pass a dictionary of AVOptions to nested contexts that are
221  * allocated during init.
222  *
223  * On return, the options dict should be freed and replaced with one that
224  * contains all the options which could not be processed by this filter (or
225  * with NULL if all the options were processed).
226  *
227  * Otherwise the semantics is the same as for @ref AVFilter.init "init".
228  */
230 
231  /**
232  * Filter uninitialization function.
233  *
234  * Called only once right before the filter is freed. Should deallocate any
235  * memory held by the filter, release any buffer references, etc. It does
236  * not need to deallocate the AVFilterContext.priv memory itself.
237  *
238  * This callback may be called even if @ref AVFilter.init "init" was not
239  * called or failed, so it must be prepared to handle such a situation.
240  */
242 
243  /**
244  * Query formats supported by the filter on its inputs and outputs.
245  *
246  * This callback is called after the filter is initialized (so the inputs
247  * and outputs are fixed), shortly before the format negotiation. This
248  * callback may be called more than once.
249  *
250  * This callback must set AVFilterLink.out_formats on every input link and
251  * AVFilterLink.in_formats on every output link to a list of pixel/sample
252  * formats that the filter supports on that link. For audio links, this
253  * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" /
254  * @ref AVFilterLink.out_samplerates "out_samplerates" and
255  * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" /
256  * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously.
257  *
258  * This callback may be NULL for filters with one input, in which case
259  * libavfilter assumes that it supports all input formats and preserves
260  * them on output.
261  *
262  * @return zero on success, a negative value corresponding to an
263  * AVERROR code otherwise
264  */
266 
267  int priv_size; ///< size of private data to allocate for the filter
268 
269  /**
270  * Used by the filter registration system. Must not be touched by any other
271  * code.
272  */
273  struct AVFilter *next;
274 
275  /**
276  * Make the filter instance process a command.
277  *
278  * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
279  * @param arg the argument for the command
280  * @param res a buffer with size res_size where the filter(s) can return a response. This must not change when the command is not supported.
281  * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
282  * time consuming then a filter should treat it like an unsupported command
283  *
284  * @returns >=0 on success otherwise an error code.
285  * AVERROR(ENOSYS) on unsupported commands
286  */
287  int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
288 
289  /**
290  * Filter initialization function, alternative to the init()
291  * callback. Args contains the user-supplied parameters, opaque is
292  * used for providing binary data.
293  */
294  int (*init_opaque)(AVFilterContext *ctx, void *opaque);
295 } AVFilter;
296 
297 /**
298  * Process multiple parts of the frame concurrently.
299  */
300 #define AVFILTER_THREAD_SLICE (1 << 0)
301 
302 typedef struct AVFilterInternal AVFilterInternal;
303 
304 /** An instance of a filter */
306  const AVClass *av_class; ///< needed for av_log() and filters common options
307 
308  const AVFilter *filter; ///< the AVFilter of which this is an instance
309 
310  char *name; ///< name of this filter instance
311 
312  AVFilterPad *input_pads; ///< array of input pads
313  AVFilterLink **inputs; ///< array of pointers to input links
314  unsigned nb_inputs; ///< number of input pads
315 
316  AVFilterPad *output_pads; ///< array of output pads
317  AVFilterLink **outputs; ///< array of pointers to output links
318  unsigned nb_outputs; ///< number of output pads
319 
320  void *priv; ///< private data for use by the filter
321 
322  struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
323 
324  /**
325  * Type of multithreading being allowed/used. A combination of
326  * AVFILTER_THREAD_* flags.
327  *
328  * May be set by the caller before initializing the filter to forbid some
329  * or all kinds of multithreading for this filter. The default is allowing
330  * everything.
331  *
332  * When the filter is initialized, this field is combined using bit AND with
333  * AVFilterGraph.thread_type to get the final mask used for determining
334  * allowed threading types. I.e. a threading type needs to be set in both
335  * to be allowed.
336  *
337  * After the filter is initialized, libavfilter sets this field to the
338  * threading type that is actually used (0 for no multithreading).
339  */
341 
342  /**
343  * An opaque struct for libavfilter internal use.
344  */
345  AVFilterInternal *internal;
346 
347  /**
348  * For filters which will create hardware frames, sets the device the
349  * filter should create them in. All other filters will ignore this field:
350  * in particular, a filter which consumes or processes hardware frames will
351  * instead use the hw_frames_ctx field in AVFilterLink to carry the
352  * hardware context information.
353  */
355 
357 
358  char *enable_str; ///< enable expression string
359  void *enable; ///< parsed expression (AVExpr*)
360  double *var_values; ///< variable values for the enable expression
361  int is_disabled; ///< the enabled state from the last expression evaluation
362 };
363 
364 /**
365  * A link between two filters. This contains pointers to the source and
366  * destination filters between which this link exists, and the indexes of
367  * the pads involved. In addition, this link also contains the parameters
368  * which have been negotiated and agreed upon between the filter, such as
369  * image dimensions, format, etc.
370  */
371 struct AVFilterLink {
372  AVFilterContext *src; ///< source filter
373  AVFilterPad *srcpad; ///< output pad on the source filter
374 
375  AVFilterContext *dst; ///< dest filter
376  AVFilterPad *dstpad; ///< input pad on the dest filter
377 
378  enum AVMediaType type; ///< filter media type
379 
380  /* These parameters apply only to video */
381  int w; ///< agreed upon image width
382  int h; ///< agreed upon image height
383  AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
384  /* These parameters apply only to audio */
385  uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
386  int sample_rate; ///< samples per second
387 
388  int format; ///< agreed upon media format
389 
390  /**
391  * Define the time base used by the PTS of the frames/samples
392  * which will pass through this link.
393  * During the configuration stage, each filter is supposed to
394  * change only the output timebase, while the timebase of the
395  * input link is assumed to be an unchangeable property.
396  */
398 
399  /*****************************************************************
400  * All fields below this line are not part of the public API. They
401  * may not be used outside of libavfilter and can be changed and
402  * removed at will.
403  * New public fields should be added right above.
404  *****************************************************************
405  */
406  /**
407  * Lists of formats and channel layouts supported by the input and output
408  * filters respectively. These lists are used for negotiating the format
409  * to actually be used, which will be loaded into the format and
410  * channel_layout members, above, when chosen.
411  *
412  */
415 
416  /**
417  * Lists of channel layouts and sample rates used for automatic
418  * negotiation.
419  */
424 
425  /**
426  * Audio only, the destination filter sets this to a non-zero value to
427  * request that buffers with the given number of samples should be sent to
428  * it. AVFilterPad.needs_fifo must also be set on the corresponding input
429  * pad.
430  * Last buffer before EOF will be padded with silence.
431  */
433 
434  /** stage of the initialization of the link properties (dimensions, etc) */
435  enum {
436  AVLINK_UNINIT = 0, ///< not started
437  AVLINK_STARTINIT, ///< started, but incomplete
438  AVLINK_INIT ///< complete
439  } init_state;
440 
441  /**
442  * Graph the filter belongs to.
443  */
445 
446  /**
447  * Current timestamp of the link, as defined by the most recent
448  * frame(s), in link time_base units.
449  */
450  int64_t current_pts;
451 
452  /**
453  * Current timestamp of the link, as defined by the most recent
454  * frame(s), in AV_TIME_BASE units.
455  */
456  int64_t current_pts_us;
457 
458  /**
459  * Index in the age array.
460  */
462 
463  /**
464  * Frame rate of the stream on the link, or 1/0 if unknown or variable;
465  * if left to 0/0, will be automatically copied from the first input
466  * of the source filter if it exists.
467  *
468  * Sources should set it to the best estimation of the real frame rate.
469  * If the source frame rate is unknown or variable, set this to 1/0.
470  * Filters should update it if necessary depending on their function.
471  * Sinks can use it to set a default output frame rate.
472  * It is similar to the r_frame_rate field in AVStream.
473  */
475 
476  /**
477  * For hwaccel pixel formats, this should be a reference to the
478  * AVHWFramesContext describing the frames.
479  */
481 
482  /**
483  * Buffer partially filled with samples to achieve a fixed/minimum size.
484  */
486 
487  /**
488  * Size of the partial buffer to allocate.
489  * Must be between min_samples and max_samples.
490  */
492 
493  /**
494  * Minimum number of samples to filter at once. If filter_frame() is
495  * called with fewer samples, it will accumulate them in partial_buf.
496  * This field and the related ones must not be changed after filtering
497  * has started.
498  * If 0, all related fields are ignored.
499  */
501 
502  /**
503  * Maximum number of samples to filter at once. If filter_frame() is
504  * called with more samples, it will split them.
505  */
507 
508  /**
509  * Link status.
510  * If not zero, all attempts of filter_frame or request_frame
511  * will fail with the corresponding code, and if necessary the reference
512  * will be destroyed.
513  * If request_frame returns an error, the status is set on the
514  * corresponding link.
515  * It can be set also be set by either the source or the destination
516  * filter.
517  */
518  int status;
519 
520  /**
521  * Number of channels.
522  */
523  int channels;
524 
525  /**
526  * Link processing flags.
527  */
528  unsigned flags;
529 
530  /**
531  * Number of past frames sent through the link.
532  */
533  int64_t frame_count;
534 
535  /**
536  * A pointer to a FFVideoFramePool struct.
537  */
539 
540  /**
541  * True if a frame is currently wanted on the input of this filter.
542  * Set when ff_request_frame() is called by the output,
543  * cleared when the request is handled or forwarded.
544  */
546 
547  /**
548  * True if a frame is currently wanted on the output of this filter.
549  * Set when ff_request_frame() is called by the output,
550  * cleared when a frame is filtered.
551  */
553 };
554 
555 /**
556  * Link two filters together.
557  *
558  * @param src the source filter
559  * @param srcpad index of the output pad on the source filter
560  * @param dst the destination filter
561  * @param dstpad index of the input pad on the destination filter
562  * @return zero on success
563  */
564 int avfilter_link(AVFilterContext *src, unsigned srcpad,
565  AVFilterContext *dst, unsigned dstpad);
566 
567 /**
568  * Free the link in *link, and set its pointer to NULL.
569  */
570 void avfilter_link_free(AVFilterLink **link);
571 
572 /**
573  * Get the number of channels of a link.
574  */
576 
577 /**
578  * Set the closed field of a link.
579  * @deprecated applications are not supposed to mess with links, they should
580  * close the sinks.
581  */
583 void avfilter_link_set_closed(AVFilterLink *link, int closed);
584 
585 /**
586  * Negotiate the media format, dimensions, etc of all inputs to a filter.
587  *
588  * @param filter the filter to negotiate the properties for its inputs
589  * @return zero on successful negotiation
590  */
592 
593 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
594 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
595 
596 /**
597  * Make the filter instance process a command.
598  * It is recommended to use avfilter_graph_send_command().
599  */
600 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
601 
602 /** Initialize the filter system. Register all builtin filters. */
603 void avfilter_register_all(void);
604 
605 #if FF_API_OLD_FILTER_REGISTER
606 /** Uninitialize the filter system. Unregister all filters. */
608 void avfilter_uninit(void);
609 #endif
610 
611 /**
612  * Register a filter. This is only needed if you plan to use
613  * avfilter_get_by_name later to lookup the AVFilter structure by name. A
614  * filter can still by instantiated with avfilter_graph_alloc_filter even if it
615  * is not registered.
616  *
617  * @param filter the filter to register
618  * @return 0 if the registration was successful, a negative value
619  * otherwise
620  */
622 
623 /**
624  * Get a filter definition matching the given name.
625  *
626  * @param name the filter name to find
627  * @return the filter definition, if any matching one is registered.
628  * NULL if none found.
629  */
630 #if !FF_API_NOCONST_GET_NAME
631 const
632 #endif
633 AVFilter *avfilter_get_by_name(const char *name);
634 
635 /**
636  * Iterate over all registered filters.
637  * @return If prev is non-NULL, next registered filter after prev or NULL if
638  * prev is the last filter. If prev is NULL, return the first registered filter.
639  */
640 const AVFilter *avfilter_next(const AVFilter *prev);
641 
642 #if FF_API_OLD_FILTER_REGISTER
643 /**
644  * If filter is NULL, returns a pointer to the first registered filter pointer,
645  * if filter is non-NULL, returns the next pointer after filter.
646  * If the returned pointer points to NULL, the last registered filter
647  * was already reached.
648  * @deprecated use avfilter_next()
649  */
651 AVFilter **av_filter_next(AVFilter **filter);
652 #endif
653 
654 #if FF_API_AVFILTER_OPEN
655 /**
656  * Create a filter instance.
657  *
658  * @param filter_ctx put here a pointer to the created filter context
659  * on success, NULL on failure
660  * @param filter the filter to create an instance of
661  * @param inst_name Name to give to the new instance. Can be NULL for none.
662  * @return >= 0 in case of success, a negative error code otherwise
663  * @deprecated use avfilter_graph_alloc_filter() instead
664  */
666 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
667 #endif
668 
669 
670 #if FF_API_AVFILTER_INIT_FILTER
671 /**
672  * Initialize a filter.
673  *
674  * @param filter the filter to initialize
675  * @param args A string of parameters to use when initializing the filter.
676  * The format and meaning of this string varies by filter.
677  * @param opaque Any extra non-string data needed by the filter. The meaning
678  * of this parameter varies by filter.
679  * @return zero on success
680  */
682 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
683 #endif
684 
685 /**
686  * Initialize a filter with the supplied parameters.
687  *
688  * @param ctx uninitialized filter context to initialize
689  * @param args Options to initialize the filter with. This must be a
690  * ':'-separated list of options in the 'key=value' form.
691  * May be NULL if the options have been set directly using the
692  * AVOptions API or there are no options that need to be set.
693  * @return 0 on success, a negative AVERROR on failure
694  */
695 int avfilter_init_str(AVFilterContext *ctx, const char *args);
696 
697 /**
698  * Initialize a filter with the supplied dictionary of options.
699  *
700  * @param ctx uninitialized filter context to initialize
701  * @param options An AVDictionary filled with options for this filter. On
702  * return this parameter will be destroyed and replaced with
703  * a dict containing options that were not found. This dictionary
704  * must be freed by the caller.
705  * May be NULL, then this function is equivalent to
706  * avfilter_init_str() with the second parameter set to NULL.
707  * @return 0 on success, a negative AVERROR on failure
708  *
709  * @note This function and avfilter_init_str() do essentially the same thing,
710  * the difference is in manner in which the options are passed. It is up to the
711  * calling code to choose whichever is more preferable. The two functions also
712  * behave differently when some of the provided options are not declared as
713  * supported by the filter. In such a case, avfilter_init_str() will fail, but
714  * this function will leave those extra options in the options AVDictionary and
715  * continue as usual.
716  */
718 
719 /**
720  * Free a filter context. This will also remove the filter from its
721  * filtergraph's list of filters.
722  *
723  * @param filter the filter to free
724  */
726 
727 /**
728  * Insert a filter in the middle of an existing link.
729  *
730  * @param link the link into which the filter should be inserted
731  * @param filt the filter to be inserted
732  * @param filt_srcpad_idx the input pad on the filter to connect
733  * @param filt_dstpad_idx the output pad on the filter to connect
734  * @return zero on success
735  */
737  unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
738 
739 /**
740  * @return AVClass for AVFilterContext.
741  *
742  * @see av_opt_find().
743  */
744 const AVClass *avfilter_get_class(void);
745 
747 
748 /**
749  * A function pointer passed to the @ref AVFilterGraph.execute callback to be
750  * executed multiple times, possibly in parallel.
751  *
752  * @param ctx the filter context the job belongs to
753  * @param arg an opaque parameter passed through from @ref
754  * AVFilterGraph.execute
755  * @param jobnr the index of the job being executed
756  * @param nb_jobs the total number of jobs
757  *
758  * @return 0 on success, a negative AVERROR on error
759  */
760 typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
761 
762 /**
763  * A function executing multiple jobs, possibly in parallel.
764  *
765  * @param ctx the filter context to which the jobs belong
766  * @param func the function to be called multiple times
767  * @param arg the argument to be passed to func
768  * @param ret a nb_jobs-sized array to be filled with return values from each
769  * invocation of func
770  * @param nb_jobs the number of jobs to execute
771  *
772  * @return 0 on success, a negative AVERROR on error
773  */
775  void *arg, int *ret, int nb_jobs);
776 
777 typedef struct AVFilterGraph {
780  unsigned nb_filters;
781 
782  char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
783  char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
784 
785  /**
786  * Type of multithreading allowed for filters in this graph. A combination
787  * of AVFILTER_THREAD_* flags.
788  *
789  * May be set by the caller at any point, the setting will apply to all
790  * filters initialized after that. The default is allowing everything.
791  *
792  * When a filter in this graph is initialized, this field is combined using
793  * bit AND with AVFilterContext.thread_type to get the final mask used for
794  * determining allowed threading types. I.e. a threading type needs to be
795  * set in both to be allowed.
796  */
798 
799  /**
800  * Maximum number of threads used by filters in this graph. May be set by
801  * the caller before adding any filters to the filtergraph. Zero (the
802  * default) means that the number of threads is determined automatically.
803  */
805 
806  /**
807  * Opaque object for libavfilter internal use.
808  */
810 
811  /**
812  * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
813  * be used from callbacks like @ref AVFilterGraph.execute.
814  * Libavfilter will not touch this field in any way.
815  */
816  void *opaque;
817 
818  /**
819  * This callback may be set by the caller immediately after allocating the
820  * graph and before adding any filters to it, to provide a custom
821  * multithreading implementation.
822  *
823  * If set, filters with slice threading capability will call this callback
824  * to execute multiple jobs in parallel.
825  *
826  * If this field is left unset, libavfilter will use its internal
827  * implementation, which may or may not be multithreaded depending on the
828  * platform and build options.
829  */
831 
832  char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
833 
834  /**
835  * Private fields
836  *
837  * The following fields are for internal use only.
838  * Their type, offset, number and semantic can change without notice.
839  */
840 
843 
845 } AVFilterGraph;
846 
847 /**
848  * Allocate a filter graph.
849  *
850  * @return the allocated filter graph on success or NULL.
851  */
853 
854 /**
855  * Create a new filter instance in a filter graph.
856  *
857  * @param graph graph in which the new filter will be used
858  * @param filter the filter to create an instance of
859  * @param name Name to give to the new instance (will be copied to
860  * AVFilterContext.name). This may be used by the caller to identify
861  * different filters, libavfilter itself assigns no semantics to
862  * this parameter. May be NULL.
863  *
864  * @return the context of the newly created filter instance (note that it is
865  * also retrievable directly through AVFilterGraph.filters or with
866  * avfilter_graph_get_filter()) on success or NULL on failure.
867  */
869  const AVFilter *filter,
870  const char *name);
871 
872 /**
873  * Get a filter instance identified by instance name from graph.
874  *
875  * @param graph filter graph to search through.
876  * @param name filter instance name (should be unique in the graph).
877  * @return the pointer to the found filter instance or NULL if it
878  * cannot be found.
879  */
881 
882 #if FF_API_AVFILTER_OPEN
883 /**
884  * Add an existing filter instance to a filter graph.
885  *
886  * @param graphctx the filter graph
887  * @param filter the filter to be added
888  *
889  * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a
890  * filter graph
891  */
893 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
894 #endif
895 
896 /**
897  * Create and add a filter instance into an existing graph.
898  * The filter instance is created from the filter filt and inited
899  * with the parameters args and opaque.
900  *
901  * In case of success put in *filt_ctx the pointer to the created
902  * filter instance, otherwise set *filt_ctx to NULL.
903  *
904  * @param name the instance name to give to the created filter instance
905  * @param graph_ctx the filter graph
906  * @return a negative AVERROR error code in case of failure, a non
907  * negative value otherwise
908  */
910  const char *name, const char *args, void *opaque,
911  AVFilterGraph *graph_ctx);
912 
913 /**
914  * Enable or disable automatic format conversion inside the graph.
915  *
916  * Note that format conversion can still happen inside explicitly inserted
917  * scale and aresample filters.
918  *
919  * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
920  */
922 
923 enum {
924  AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
925  AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
926 };
927 
928 /**
929  * Check validity and configure all the links and formats in the graph.
930  *
931  * @param graphctx the filter graph
932  * @param log_ctx context used for logging
933  * @return >= 0 in case of success, a negative AVERROR code otherwise
934  */
935 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
936 
937 /**
938  * Free a graph, destroy its links, and set *graph to NULL.
939  * If *graph is NULL, do nothing.
940  */
941 void avfilter_graph_free(AVFilterGraph **graph);
942 
943 /**
944  * A linked-list of the inputs/outputs of the filter chain.
945  *
946  * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
947  * where it is used to communicate open (unlinked) inputs and outputs from and
948  * to the caller.
949  * This struct specifies, per each not connected pad contained in the graph, the
950  * filter context and the pad index required for establishing a link.
951  */
952 typedef struct AVFilterInOut {
953  /** unique name for this input/output in the list */
954  char *name;
955 
956  /** filter context associated to this input/output */
958 
959  /** index of the filt_ctx pad to use for linking */
960  int pad_idx;
961 
962  /** next input/input in the list, NULL if this is the last */
964 } AVFilterInOut;
965 
966 /**
967  * Allocate a single AVFilterInOut entry.
968  * Must be freed with avfilter_inout_free().
969  * @return allocated AVFilterInOut on success, NULL on failure.
970  */
972 
973 /**
974  * Free the supplied list of AVFilterInOut and set *inout to NULL.
975  * If *inout is NULL, do nothing.
976  */
977 void avfilter_inout_free(AVFilterInOut **inout);
978 
979 /**
980  * Add a graph described by a string to a graph.
981  *
982  * @note The caller must provide the lists of inputs and outputs,
983  * which therefore must be known before calling the function.
984  *
985  * @note The inputs parameter describes inputs of the already existing
986  * part of the graph; i.e. from the point of view of the newly created
987  * part, they are outputs. Similarly the outputs parameter describes
988  * outputs of the already existing filters, which are provided as
989  * inputs to the parsed filters.
990  *
991  * @param graph the filter graph where to link the parsed graph context
992  * @param filters string to be parsed
993  * @param inputs linked list to the inputs of the graph
994  * @param outputs linked list to the outputs of the graph
995  * @return zero on success, a negative AVERROR code on error
996  */
997 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
999  void *log_ctx);
1000 
1001 /**
1002  * Add a graph described by a string to a graph.
1003  *
1004  * In the graph filters description, if the input label of the first
1005  * filter is not specified, "in" is assumed; if the output label of
1006  * the last filter is not specified, "out" is assumed.
1007  *
1008  * @param graph the filter graph where to link the parsed graph context
1009  * @param filters string to be parsed
1010  * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
1011  * If non-NULL, *inputs is updated to contain the list of open inputs
1012  * after the parsing, should be freed with avfilter_inout_free().
1013  * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
1014  * If non-NULL, *outputs is updated to contain the list of open outputs
1015  * after the parsing, should be freed with avfilter_inout_free().
1016  * @return non negative on success, a negative AVERROR code on error
1017  */
1018 int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters,
1020  void *log_ctx);
1021 
1022 /**
1023  * Add a graph described by a string to a graph.
1024  *
1025  * @param[in] graph the filter graph where to link the parsed graph context
1026  * @param[in] filters string to be parsed
1027  * @param[out] inputs a linked list of all free (unlinked) inputs of the
1028  * parsed graph will be returned here. It is to be freed
1029  * by the caller using avfilter_inout_free().
1030  * @param[out] outputs a linked list of all free (unlinked) outputs of the
1031  * parsed graph will be returned here. It is to be freed by the
1032  * caller using avfilter_inout_free().
1033  * @return zero on success, a negative AVERROR code on error
1034  *
1035  * @note This function returns the inputs and outputs that are left
1036  * unlinked after parsing the graph and the caller then deals with
1037  * them.
1038  * @note This function makes no reference whatsoever to already
1039  * existing parts of the graph and the inputs parameter will on return
1040  * contain inputs of the newly parsed part of the graph. Analogously
1041  * the outputs parameter will contain outputs of the newly created
1042  * filters.
1043  */
1044 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
1047 
1048 /**
1049  * Send a command to one or more filter instances.
1050  *
1051  * @param graph the filter graph
1052  * @param target the filter(s) to which the command should be sent
1053  * "all" sends to all filters
1054  * otherwise it can be a filter or filter instance name
1055  * which will send the command to all matching filters.
1056  * @param cmd the command to send, for handling simplicity all commands must be alphanumeric only
1057  * @param arg the argument for the command
1058  * @param res a buffer with size res_size where the filter(s) can return a response.
1059  *
1060  * @returns >=0 on success otherwise an error code.
1061  * AVERROR(ENOSYS) on unsupported commands
1062  */
1063 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
1064 
1065 /**
1066  * Queue a command for one or more filter instances.
1067  *
1068  * @param graph the filter graph
1069  * @param target the filter(s) to which the command should be sent
1070  * "all" sends to all filters
1071  * otherwise it can be a filter or filter instance name
1072  * which will send the command to all matching filters.
1073  * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
1074  * @param arg the argument for the command
1075  * @param ts time at which the command should be sent to the filter
1076  *
1077  * @note As this executes commands after this function returns, no return code
1078  * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
1079  */
1080 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
1081 
1082 
1083 /**
1084  * Dump a graph into a human-readable string representation.
1085  *
1086  * @param graph the graph to dump
1087  * @param options formatting options; currently ignored
1088  * @return a string, or NULL in case of memory allocation failure;
1089  * the string must be freed using av_free
1090  */
1091 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
1092 
1093 /**
1094  * Request a frame on the oldest sink link.
1095  *
1096  * If the request returns AVERROR_EOF, try the next.
1097  *
1098  * Note that this function is not meant to be the sole scheduling mechanism
1099  * of a filtergraph, only a convenience function to help drain a filtergraph
1100  * in a balanced way under normal circumstances.
1101  *
1102  * Also note that AVERROR_EOF does not mean that frames did not arrive on
1103  * some of the sinks during the process.
1104  * When there are multiple sink links, in case the requested link
1105  * returns an EOF, this may cause a filter to flush pending frames
1106  * which are sent to another sink link, although unrequested.
1107  *
1108  * @return the return value of ff_request_frame(),
1109  * or AVERROR_EOF if all links returned AVERROR_EOF
1110  */
1112 
1113 /**
1114  * @}
1115  */
1116 
1117 #endif /* AVFILTER_AVFILTER_H */
AVFilterContext ** filters
Definition: avfilter.h:779
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:360
int sink_links_count
Definition: avfilter.h:842
This structure describes decoded (raw) audio or video data.
Definition: frame.h:180
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:797
void avfilter_free(AVFilterContext *filter)
Free a filter context.
Definition: avfilter.c:742
AVFormatContext * ctx
Definition: movenc-test.c:48
AVFilterGraph * avfilter_graph_alloc(void)
Allocate a filter graph.
Definition: avfiltergraph.c:76
all automatic conversions disabled
Definition: avfilter.h:925
int(* init)(AVFilterContext *ctx)
Filter initialization function.
Definition: avfilter.h:216
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:963
enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx)
Get the type of an AVFilterPad.
Definition: avfilter.c:1030
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:354
external API header
int(* query_formats)(AVFilterContext *)
Query formats supported by the filter on its inputs and outputs.
Definition: avfilter.h:265
int thread_type
Type of multithreading being allowed/used.
Definition: avfilter.h:340
int is_disabled
the enabled state from the last expression evaluation
Definition: avfilter.h:361
Macro definitions for various function/variable attributes.
char * scale_sws_opts
sws options to use for the auto-inserted scale filters
Definition: avfilter.h:782
struct AVFilterGraph * graph
filtergraph this filter belongs to
Definition: avfilter.h:322
int priv_size
size of private data to allocate for the filter
Definition: avfilter.h:267
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:313
char * name
name of this filter instance
Definition: avfilter.h:310
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:830
int avfilter_link(AVFilterContext *src, unsigned srcpad, AVFilterContext *dst, unsigned dstpad)
Link two filters together.
Definition: avfilter.c:133
AVFilterPad * output_pads
array of output pads
Definition: avfilter.h:316
const char * avfilter_license(void)
Return the libavfilter license.
Definition: avfilter.c:86
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:185
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:783
int nb_threads
Maximum number of threads used by filters in this graph.
Definition: avfilter.h:804
int avfilter_config_links(AVFilterContext *filter)
Negotiate the media format, dimensions, etc of all inputs to a filter.
Definition: avfilter.c:237
const AVFilter * avfilter_next(const AVFilter *prev)
Iterate over all registered filters.
Definition: avfilter.c:549
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:241
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:287
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:3967
A filter pad used for either input or output.
Definition: internal.h:53
AVFilterPad * input_pads
array of input pads
Definition: avfilter.h:312
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:760
int avfilter_link_get_channels(AVFilterLink *link)
Get the number of channels of a link.
Definition: avfilter.c:178
const AVClass * av_class
Definition: avfilter.h:778
unsigned nb_outputs
number of output pads
Definition: avfilter.h:318
unsigned avfilter_version(void)
Return the LIBAVFILTER_VERSION_INT constant.
Definition: avfilter.c:75
void * priv
private data for use by the filter
Definition: avfilter.h:320
char * enable_str
enable expression string
Definition: avfilter.h:358
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:229
static FilteringContext * filter_ctx
Definition: transcoding.c:46
AVFilterLink ** sink_links
Private fields.
Definition: avfilter.h:841
reference-counted frame API
const AVFilter * avfilter_get_by_name(const char *name)
Get a filter definition matching the given name.
Definition: avfilter.c:519
attribute_deprecated void avfilter_link_set_closed(AVFilterLink *link, int closed)
Set the closed field of a link.
Definition: avfilter.c:195
unsigned nb_inputs
number of input pads
Definition: avfilter.h:314
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
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:294
#define src
Definition: vp9dsp.c:530
AVFilterContext * filter_ctx
filter context associated to this input/output
Definition: avfilter.h:957
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:906
const AVFilterPad * inputs
List of inputs, terminated by a zeroed element.
Definition: avfilter.h:162
const AVClass * avfilter_get_class(void)
Definition: avfilter.c:1230
A linked-list of the inputs/outputs of the filter chain.
Definition: avfilter.h:952
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:200
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:774
const AVClass * priv_class
A class for the private data, used to declare filter private AVOptions.
Definition: avfilter.h:180
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:492
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:142
int pad_idx
index of the filt_ctx pad to use for linking
Definition: avfilter.h:960
rational number numerator/denominator
Definition: rational.h:43
struct AVFilter * next
Used by the filter registration system.
Definition: avfilter.h:273
int(* func)(AVBPrint *dst, const char *in, const char *arg)
Definition: jacosubdec.c:67
AVMediaType
Definition: avutil.h:191
refcounted data buffer API
const char * name
Filter name.
Definition: avfilter.h:146
unsigned nb_filters
Definition: avfilter.h:780
const char * avfilter_configuration(void)
Return the libavfilter build-time configuration.
Definition: avfilter.c:81
const char * avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx)
Get the name of an AVFilterPad.
Definition: avfilter.c:1025
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:317
char * name
unique name for this input/output in the list
Definition: avfilter.h:954
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:869
A reference to a data buffer.
Definition: buffer.h:81
void * opaque
Opaque user data.
Definition: avfilter.h:816
AVFilterInOut * avfilter_inout_alloc(void)
Allocate a single AVFilterInOut entry.
Definition: graphparser.c:182
rational numbers
struct AVFilterCommand * command_queue
Definition: avfilter.h:356
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:832
pixel format definitions
const char * description
A description of the filter.
Definition: avfilter.h:153
int avfilter_register(AVFilter *filter)
Register a filter.
Definition: avfilter.c:533
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:359
const AVClass * av_class
needed for av_log() and filters common options
Definition: avfilter.h:306
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:305
int avfilter_pad_count(const AVFilterPad *pads)
Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
Definition: avfilter.c:565
all automatic conversions enabled
Definition: avfilter.h:924
const AVFilterPad * outputs
List of outputs, terminated by a zeroed element.
Definition: avfilter.h:170
void avfilter_link_free(AVFilterLink **link)
Free the link in *link, and set its pointer to NULL.
Definition: avfilter.c:167
const AVFilter * filter
the AVFilter of which this is an instance
Definition: avfilter.h:308
unsigned disable_auto_convert
Definition: avfilter.h:844
const char * name
Definition: opengl_enc.c:103