e945a07bd82d736e1714cf777d325ce03e638c66
[libav.git] / libavfilter / avfilter.h
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 #include "libavutil/avutil.h"
26
27 #define LIBAVFILTER_VERSION_MAJOR 1
28 #define LIBAVFILTER_VERSION_MINOR 26
29 #define LIBAVFILTER_VERSION_MICRO 1
30
31 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
32 LIBAVFILTER_VERSION_MINOR, \
33 LIBAVFILTER_VERSION_MICRO)
34 #define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
35 LIBAVFILTER_VERSION_MINOR, \
36 LIBAVFILTER_VERSION_MICRO)
37 #define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
38
39 #include <stddef.h>
40 #include "libavcodec/avcodec.h"
41
42 /**
43 * Return the LIBAVFILTER_VERSION_INT constant.
44 */
45 unsigned avfilter_version(void);
46
47 /**
48 * Return the libavfilter build-time configuration.
49 */
50 const char *avfilter_configuration(void);
51
52 /**
53 * Return the libavfilter license.
54 */
55 const char *avfilter_license(void);
56
57
58 typedef struct AVFilterContext AVFilterContext;
59 typedef struct AVFilterLink AVFilterLink;
60 typedef struct AVFilterPad AVFilterPad;
61
62 /**
63 * A reference-counted buffer data type used by the filter system. Filters
64 * should not store pointers to this structure directly, but instead use the
65 * AVFilterPicRef structure below.
66 */
67 typedef struct AVFilterBuffer
68 {
69 uint8_t *data[4]; ///< buffer data for each plane
70 int linesize[4]; ///< number of bytes per line
71 int format; ///< media format
72
73 unsigned refcount; ///< number of references to this buffer
74
75 /** private data to be used by a custom free function */
76 void *priv;
77 /**
78 * A pointer to the function to deallocate this buffer if the default
79 * function is not sufficient. This could, for example, add the memory
80 * back into a memory pool to be reused later without the overhead of
81 * reallocating it from scratch.
82 */
83 void (*free)(struct AVFilterBuffer *buf);
84 } AVFilterBuffer;
85
86 #define AV_PERM_READ 0x01 ///< can read from the buffer
87 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
88 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
89 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
90 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
91
92 /**
93 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
94 * a picture to, for example, crop image without any memcpy, the picture origin
95 * and dimensions are per-reference properties. Linesize is also useful for
96 * image flipping, frame to field filters, etc, and so is also per-reference.
97 *
98 * TODO: add anything necessary for frame reordering
99 */
100 typedef struct AVFilterPicRef
101 {
102 AVFilterBuffer *pic; ///< the picture that this is a reference to
103 uint8_t *data[4]; ///< picture data for each plane
104 int linesize[4]; ///< number of bytes per line
105 int w; ///< image width
106 int h; ///< image height
107
108 int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
109 int64_t pos; ///< byte position in stream, -1 if unknown
110
111 AVRational pixel_aspect; ///< pixel aspect ratio
112
113 int perms; ///< permissions, see the AV_PERM_* flags
114
115 int interlaced; ///< is frame interlaced
116 int top_field_first;
117 } AVFilterPicRef;
118
119 /**
120 * Copy properties of src to dst, without copying the actual video
121 * data.
122 */
123 static inline void avfilter_copy_picref_props(AVFilterPicRef *dst, AVFilterPicRef *src)
124 {
125 dst->pts = src->pts;
126 dst->pos = src->pos;
127 dst->pixel_aspect = src->pixel_aspect;
128 dst->interlaced = src->interlaced;
129 dst->top_field_first = src->top_field_first;
130 }
131
132 /**
133 * Add a new reference to a picture.
134 * @param ref an existing reference to the picture
135 * @param pmask a bitmask containing the allowable permissions in the new
136 * reference
137 * @return a new reference to the picture with the same properties as the
138 * old, excluding any permissions denied by pmask
139 */
140 AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
141
142 /**
143 * Remove a reference to a picture. If this is the last reference to the
144 * picture, the picture itself is also automatically freed.
145 * @param ref reference to the picture
146 */
147 void avfilter_unref_pic(AVFilterPicRef *ref);
148
149 /**
150 * A list of supported formats for one end of a filter link. This is used
151 * during the format negotiation process to try to pick the best format to
152 * use to minimize the number of necessary conversions. Each filter gives a
153 * list of the formats supported by each input and output pad. The list
154 * given for each pad need not be distinct - they may be references to the
155 * same list of formats, as is often the case when a filter supports multiple
156 * formats, but will always output the same format as it is given in input.
157 *
158 * In this way, a list of possible input formats and a list of possible
159 * output formats are associated with each link. When a set of formats is
160 * negotiated over a link, the input and output lists are merged to form a
161 * new list containing only the common elements of each list. In the case
162 * that there were no common elements, a format conversion is necessary.
163 * Otherwise, the lists are merged, and all other links which reference
164 * either of the format lists involved in the merge are also affected.
165 *
166 * For example, consider the filter chain:
167 * filter (a) --> (b) filter (b) --> (c) filter
168 *
169 * where the letters in parenthesis indicate a list of formats supported on
170 * the input or output of the link. Suppose the lists are as follows:
171 * (a) = {A, B}
172 * (b) = {A, B, C}
173 * (c) = {B, C}
174 *
175 * First, the first link's lists are merged, yielding:
176 * filter (a) --> (a) filter (a) --> (c) filter
177 *
178 * Notice that format list (b) now refers to the same list as filter list (a).
179 * Next, the lists for the second link are merged, yielding:
180 * filter (a) --> (a) filter (a) --> (a) filter
181 *
182 * where (a) = {B}.
183 *
184 * Unfortunately, when the format lists at the two ends of a link are merged,
185 * we must ensure that all links which reference either pre-merge format list
186 * get updated as well. Therefore, we have the format list structure store a
187 * pointer to each of the pointers to itself.
188 */
189 typedef struct AVFilterFormats AVFilterFormats;
190 struct AVFilterFormats
191 {
192 unsigned format_count; ///< number of formats
193 int *formats; ///< list of media formats
194
195 unsigned refcount; ///< number of references to this list
196 AVFilterFormats ***refs; ///< references to this list
197 };
198
199 /**
200 * Create a list of supported formats. This is intended for use in
201 * AVFilter->query_formats().
202 * @param fmts list of media formats, terminated by -1
203 * @return the format list, with no existing references
204 */
205 AVFilterFormats *avfilter_make_format_list(const int *fmts);
206
207 /**
208 * Add fmt to the list of media formats contained in *avff.
209 * If *avff is NULL the function allocates the filter formats struct
210 * and puts its pointer in *avff.
211 *
212 * @return a non negative value in case of success, or a negative
213 * value corresponding to an AVERROR code in case of error
214 */
215 int avfilter_add_format(AVFilterFormats **avff, int fmt);
216
217 /**
218 * Return a list of all formats supported by FFmpeg for the given media type.
219 */
220 AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
221
222 /**
223 * Return a format list which contains the intersection of the formats of
224 * a and b. Also, all the references of a, all the references of b, and
225 * a and b themselves will be deallocated.
226 *
227 * If a and b do not share any common formats, neither is modified, and NULL
228 * is returned.
229 */
230 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
231
232 /**
233 * Add *ref as a new reference to formats.
234 * That is the pointers will point like in the ascii art below:
235 * ________
236 * |formats |<--------.
237 * | ____ | ____|___________________
238 * | |refs| | | __|_
239 * | |* * | | | | | | AVFilterLink
240 * | |* *--------->|*ref|
241 * | |____| | | |____|
242 * |________| |________________________
243 */
244 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
245
246 /**
247 * If *ref is non-NULL, remove *ref as a reference to the format list
248 * it currently points to, deallocates that list if this was the last
249 * reference, and sets *ref to NULL.
250 *
251 * Before After
252 * ________ ________ NULL
253 * |formats |<--------. |formats | ^
254 * | ____ | ____|________________ | ____ | ____|________________
255 * | |refs| | | __|_ | |refs| | | __|_
256 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
257 * | |* *--------->|*ref| | |* | | | |*ref|
258 * | |____| | | |____| | |____| | | |____|
259 * |________| |_____________________ |________| |_____________________
260 */
261 void avfilter_formats_unref(AVFilterFormats **ref);
262
263 /**
264 *
265 * Before After
266 * ________ ________
267 * |formats |<---------. |formats |<---------.
268 * | ____ | ___|___ | ____ | ___|___
269 * | |refs| | | | | | |refs| | | | | NULL
270 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
271 * | |* * | | |_______| | |* * | | |_______| ___|___
272 * | |____| | | |____| | | | |
273 * |________| |________| |*oldref|
274 * |_______|
275 */
276 void avfilter_formats_changeref(AVFilterFormats **oldref,
277 AVFilterFormats **newref);
278
279 /**
280 * A filter pad used for either input or output.
281 */
282 struct AVFilterPad
283 {
284 /**
285 * Pad name. The name is unique among inputs and among outputs, but an
286 * input may have the same name as an output. This may be NULL if this
287 * pad has no need to ever be referenced by name.
288 */
289 const char *name;
290
291 /**
292 * AVFilterPad type. Only video supported now, hopefully someone will
293 * add audio in the future.
294 */
295 enum AVMediaType type;
296
297 /**
298 * Minimum required permissions on incoming buffers. Any buffer with
299 * insufficient permissions will be automatically copied by the filter
300 * system to a new buffer which provides the needed access permissions.
301 *
302 * Input pads only.
303 */
304 int min_perms;
305
306 /**
307 * Permissions which are not accepted on incoming buffers. Any buffer
308 * which has any of these permissions set will be automatically copied
309 * by the filter system to a new buffer which does not have those
310 * permissions. This can be used to easily disallow buffers with
311 * AV_PERM_REUSE.
312 *
313 * Input pads only.
314 */
315 int rej_perms;
316
317 /**
318 * Callback called before passing the first slice of a new frame. If
319 * NULL, the filter layer will default to storing a reference to the
320 * picture inside the link structure.
321 *
322 * Input video pads only.
323 */
324 void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
325
326 /**
327 * Callback function to get a buffer. If NULL, the filter system will
328 * use avfilter_default_get_video_buffer().
329 *
330 * Input video pads only.
331 */
332 AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
333
334 /**
335 * Callback called after the slices of a frame are completely sent. If
336 * NULL, the filter layer will default to releasing the reference stored
337 * in the link structure during start_frame().
338 *
339 * Input video pads only.
340 */
341 void (*end_frame)(AVFilterLink *link);
342
343 /**
344 * Slice drawing callback. This is where a filter receives video data
345 * and should do its processing.
346 *
347 * Input video pads only.
348 */
349 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
350
351 /**
352 * Frame poll callback. This returns the number of immediately available
353 * frames. It should return a positive value if the next request_frame()
354 * is guaranteed to return one frame (with no delay).
355 *
356 * Defaults to just calling the source poll_frame() method.
357 *
358 * Output video pads only.
359 */
360 int (*poll_frame)(AVFilterLink *link);
361
362 /**
363 * Frame request callback. A call to this should result in at least one
364 * frame being output over the given link. This should return zero on
365 * success, and another value on error.
366 *
367 * Output video pads only.
368 */
369 int (*request_frame)(AVFilterLink *link);
370
371 /**
372 * Link configuration callback.
373 *
374 * For output pads, this should set the link properties such as
375 * width/height. This should NOT set the format property - that is
376 * negotiated between filters by the filter system using the
377 * query_formats() callback before this function is called.
378 *
379 * For input pads, this should check the properties of the link, and update
380 * the filter's internal state as necessary.
381 *
382 * For both input and output filters, this should return zero on success,
383 * and another value on error.
384 */
385 int (*config_props)(AVFilterLink *link);
386 };
387
388 /** default handler for start_frame() for video inputs */
389 void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
390 /** default handler for draw_slice() for video inputs */
391 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
392 /** default handler for end_frame() for video inputs */
393 void avfilter_default_end_frame(AVFilterLink *link);
394 /** default handler for config_props() for video outputs */
395 int avfilter_default_config_output_link(AVFilterLink *link);
396 /** default handler for config_props() for video inputs */
397 int avfilter_default_config_input_link (AVFilterLink *link);
398 /** default handler for get_video_buffer() for video inputs */
399 AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
400 int perms, int w, int h);
401 /**
402 * A helper for query_formats() which sets all links to the same list of
403 * formats. If there are no links hooked to this filter, the list of formats is
404 * freed.
405 */
406 void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
407 /** Default handler for query_formats() */
408 int avfilter_default_query_formats(AVFilterContext *ctx);
409
410 /** start_frame() handler for filters which simply pass video along */
411 void avfilter_null_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
412
413 /** draw_slice() handler for filters which simply pass video along */
414 void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
415
416 /** end_frame() handler for filters which simply pass video along */
417 void avfilter_null_end_frame(AVFilterLink *link);
418
419 /** get_video_buffer() handler for filters which simply pass video along */
420 AVFilterPicRef *avfilter_null_get_video_buffer(AVFilterLink *link,
421 int perms, int w, int h);
422
423 /**
424 * Filter definition. This defines the pads a filter contains, and all the
425 * callback functions used to interact with the filter.
426 */
427 typedef struct AVFilter
428 {
429 const char *name; ///< filter name
430
431 int priv_size; ///< size of private data to allocate for the filter
432
433 /**
434 * Filter initialization function. Args contains the user-supplied
435 * parameters. FIXME: maybe an AVOption-based system would be better?
436 * opaque is data provided by the code requesting creation of the filter,
437 * and is used to pass data to the filter.
438 */
439 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
440
441 /**
442 * Filter uninitialization function. Should deallocate any memory held
443 * by the filter, release any picture references, etc. This does not need
444 * to deallocate the AVFilterContext->priv memory itself.
445 */
446 void (*uninit)(AVFilterContext *ctx);
447
448 /**
449 * Queries formats supported by the filter and its pads, and sets the
450 * in_formats for links connected to its output pads, and out_formats
451 * for links connected to its input pads.
452 *
453 * @return zero on success, a negative value corresponding to an
454 * AVERROR code otherwise
455 */
456 int (*query_formats)(AVFilterContext *);
457
458 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
459 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
460
461 /**
462 * A description for the filter. You should use the
463 * NULL_IF_CONFIG_SMALL() macro to define it.
464 */
465 const char *description;
466 } AVFilter;
467
468 /** An instance of a filter */
469 struct AVFilterContext
470 {
471 const AVClass *av_class; ///< needed for av_log()
472
473 AVFilter *filter; ///< the AVFilter of which this is an instance
474
475 char *name; ///< name of this filter instance
476
477 unsigned input_count; ///< number of input pads
478 AVFilterPad *input_pads; ///< array of input pads
479 AVFilterLink **inputs; ///< array of pointers to input links
480
481 unsigned output_count; ///< number of output pads
482 AVFilterPad *output_pads; ///< array of output pads
483 AVFilterLink **outputs; ///< array of pointers to output links
484
485 void *priv; ///< private data for use by the filter
486 };
487
488 /**
489 * A link between two filters. This contains pointers to the source and
490 * destination filters between which this link exists, and the indexes of
491 * the pads involved. In addition, this link also contains the parameters
492 * which have been negotiated and agreed upon between the filter, such as
493 * image dimensions, format, etc.
494 */
495 struct AVFilterLink
496 {
497 AVFilterContext *src; ///< source filter
498 unsigned int srcpad; ///< index of the output pad on the source filter
499
500 AVFilterContext *dst; ///< dest filter
501 unsigned int dstpad; ///< index of the input pad on the dest filter
502
503 /** stage of the initialization of the link properties (dimensions, etc) */
504 enum {
505 AVLINK_UNINIT = 0, ///< not started
506 AVLINK_STARTINIT, ///< started, but incomplete
507 AVLINK_INIT ///< complete
508 } init_state;
509
510 enum AVMediaType type; ///< filter media type
511
512 int w; ///< agreed upon image width
513 int h; ///< agreed upon image height
514 int format; ///< agreed upon media format
515
516 /**
517 * Lists of formats supported by the input and output filters respectively.
518 * These lists are used for negotiating the format to actually be used,
519 * which will be loaded into the format member, above, when chosen.
520 */
521 AVFilterFormats *in_formats;
522 AVFilterFormats *out_formats;
523
524 /**
525 * The picture reference currently being sent across the link by the source
526 * filter. This is used internally by the filter system to allow
527 * automatic copying of pictures which do not have sufficient permissions
528 * for the destination. This should not be accessed directly by the
529 * filters.
530 */
531 AVFilterPicRef *srcpic;
532
533 AVFilterPicRef *cur_pic;
534 AVFilterPicRef *outpic;
535 };
536
537 /**
538 * Link two filters together.
539 * @param src the source filter
540 * @param srcpad index of the output pad on the source filter
541 * @param dst the destination filter
542 * @param dstpad index of the input pad on the destination filter
543 * @return zero on success
544 */
545 int avfilter_link(AVFilterContext *src, unsigned srcpad,
546 AVFilterContext *dst, unsigned dstpad);
547
548 /**
549 * Negotiate the media format, dimensions, etc of all inputs to a filter.
550 * @param filter the filter to negotiate the properties for its inputs
551 * @return zero on successful negotiation
552 */
553 int avfilter_config_links(AVFilterContext *filter);
554
555 /**
556 * Request a picture buffer with a specific set of permissions.
557 * @param link the output link to the filter from which the picture will
558 * be requested
559 * @param perms the required access permissions
560 * @param w the minimum width of the buffer to allocate
561 * @param h the minimum height of the buffer to allocate
562 * @return A reference to the picture. This must be unreferenced with
563 * avfilter_unref_pic when you are finished with it.
564 */
565 AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
566 int w, int h);
567
568 /**
569 * Request an input frame from the filter at the other end of the link.
570 * @param link the input link
571 * @return zero on success
572 */
573 int avfilter_request_frame(AVFilterLink *link);
574
575 /**
576 * Poll a frame from the filter chain.
577 * @param link the input link
578 * @return the number of immediately available frames, a negative
579 * number in case of error
580 */
581 int avfilter_poll_frame(AVFilterLink *link);
582
583 /**
584 * Notifie the next filter of the start of a frame.
585 * @param link the output link the frame will be sent over
586 * @param picref A reference to the frame about to be sent. The data for this
587 * frame need only be valid once draw_slice() is called for that
588 * portion. The receiving filter will free this reference when
589 * it no longer needs it.
590 */
591 void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
592
593 /**
594 * Notifie the next filter that the current frame has finished.
595 * @param link the output link the frame was sent over
596 */
597 void avfilter_end_frame(AVFilterLink *link);
598
599 /**
600 * Send a slice to the next filter.
601 *
602 * Slices have to be provided in sequential order, either in
603 * top-bottom or bottom-top order. If slices are provided in
604 * non-sequential order the behavior of the function is undefined.
605 *
606 * @param link the output link over which the frame is being sent
607 * @param y offset in pixels from the top of the image for this slice
608 * @param h height of this slice in pixels
609 * @param slice_dir the assumed direction for sending slices,
610 * from the top slice to the bottom slice if the value is 1,
611 * from the bottom slice to the top slice if the value is -1,
612 * for other values the behavior of the function is undefined.
613 */
614 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
615
616 /** Initialize the filter system. Register all builtin filters. */
617 void avfilter_register_all(void);
618
619 /** Uninitialize the filter system. Unregister all filters. */
620 void avfilter_uninit(void);
621
622 /**
623 * Register a filter. This is only needed if you plan to use
624 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
625 * filter can still by instantiated with avfilter_open even if it is not
626 * registered.
627 * @param filter the filter to register
628 * @return 0 if the registration was succesfull, a negative value
629 * otherwise
630 */
631 int avfilter_register(AVFilter *filter);
632
633 /**
634 * Get a filter definition matching the given name.
635 * @param name the filter name to find
636 * @return the filter definition, if any matching one is registered.
637 * NULL if none found.
638 */
639 AVFilter *avfilter_get_by_name(const char *name);
640
641 /**
642 * If filter is NULL, returns a pointer to the first registered filter pointer,
643 * if filter is non-NULL, returns the next pointer after filter.
644 * If the returned pointer points to NULL, the last registered filter
645 * was already reached.
646 */
647 AVFilter **av_filter_next(AVFilter **filter);
648
649 /**
650 * Create a filter instance.
651 * @param filter the filter to create an instance of
652 * @param inst_name Name to give to the new instance. Can be NULL for none.
653 * @return Pointer to the new instance on success. NULL on failure.
654 */
655 AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
656
657 /**
658 * Initialize a filter.
659 * @param filter the filter to initialize
660 * @param args A string of parameters to use when initializing the filter.
661 * The format and meaning of this string varies by filter.
662 * @param opaque Any extra non-string data needed by the filter. The meaning
663 * of this parameter varies by filter.
664 * @return zero on success
665 */
666 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
667
668 /**
669 * Destroy a filter.
670 * @param filter the filter to destroy
671 */
672 void avfilter_destroy(AVFilterContext *filter);
673
674 /**
675 * Insert a filter in the middle of an existing link.
676 * @param link the link into which the filter should be inserted
677 * @param filt the filter to be inserted
678 * @param in the input pad on the filter to connect
679 * @param out the output pad on the filter to connect
680 * @return zero on success
681 */
682 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
683 unsigned in, unsigned out);
684
685 /**
686 * Insert a new pad.
687 * @param idx Insertion point. Pad is inserted at the end if this point
688 * is beyond the end of the list of pads.
689 * @param count Pointer to the number of pads in the list
690 * @param padidx_off Offset within an AVFilterLink structure to the element
691 * to increment when inserting a new pad causes link
692 * numbering to change
693 * @param pads Pointer to the pointer to the beginning of the list of pads
694 * @param links Pointer to the pointer to the beginning of the list of links
695 * @param newpad The new pad to add. A copy is made when adding.
696 */
697 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
698 AVFilterPad **pads, AVFilterLink ***links,
699 AVFilterPad *newpad);
700
701 /** Insert a new input pad for the filter. */
702 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
703 AVFilterPad *p)
704 {
705 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
706 &f->input_pads, &f->inputs, p);
707 }
708
709 /** Insert a new output pad for the filter. */
710 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
711 AVFilterPad *p)
712 {
713 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
714 &f->output_pads, &f->outputs, p);
715 }
716
717 #endif /* AVFILTER_AVFILTER_H */