lavfi: port boxblur filter from libmpcodecs
[libav.git] / libavfilter / avfilter.h
1 /*
2 * filter layer
3 * Copyright (c) 2007 Bobby Bingham
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 #include "libavutil/log.h"
27 #include "libavutil/samplefmt.h"
28 #include "libavutil/pixfmt.h"
29 #include "libavutil/rational.h"
30
31 #define LIBAVFILTER_VERSION_MAJOR 2
32 #define LIBAVFILTER_VERSION_MINOR 10
33 #define LIBAVFILTER_VERSION_MICRO 0
34
35 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
36 LIBAVFILTER_VERSION_MINOR, \
37 LIBAVFILTER_VERSION_MICRO)
38 #define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
39 LIBAVFILTER_VERSION_MINOR, \
40 LIBAVFILTER_VERSION_MICRO)
41 #define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
42
43 #include <stddef.h>
44
45 /**
46 * Return the LIBAVFILTER_VERSION_INT constant.
47 */
48 unsigned avfilter_version(void);
49
50 /**
51 * Return the libavfilter build-time configuration.
52 */
53 const char *avfilter_configuration(void);
54
55 /**
56 * Return the libavfilter license.
57 */
58 const char *avfilter_license(void);
59
60
61 typedef struct AVFilterContext AVFilterContext;
62 typedef struct AVFilterLink AVFilterLink;
63 typedef struct AVFilterPad AVFilterPad;
64
65 /**
66 * A reference-counted buffer data type used by the filter system. Filters
67 * should not store pointers to this structure directly, but instead use the
68 * AVFilterBufferRef structure below.
69 */
70 typedef struct AVFilterBuffer {
71 uint8_t *data[8]; ///< buffer data for each plane/channel
72 int linesize[8]; ///< number of bytes per line
73
74 unsigned refcount; ///< number of references to this buffer
75
76 /** private data to be used by a custom free function */
77 void *priv;
78 /**
79 * A pointer to the function to deallocate this buffer if the default
80 * function is not sufficient. This could, for example, add the memory
81 * back into a memory pool to be reused later without the overhead of
82 * reallocating it from scratch.
83 */
84 void (*free)(struct AVFilterBuffer *buf);
85
86 int format; ///< media format
87 int w, h; ///< width and height of the allocated buffer
88 } AVFilterBuffer;
89
90 #define AV_PERM_READ 0x01 ///< can read from the buffer
91 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
92 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
93 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
94 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
95 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
96
97 /**
98 * Audio specific properties in a reference to an AVFilterBuffer. Since
99 * AVFilterBufferRef is common to different media formats, audio specific
100 * per reference properties must be separated out.
101 */
102 typedef struct AVFilterBufferRefAudioProps {
103 int64_t channel_layout; ///< channel layout of audio buffer
104 int nb_samples; ///< number of audio samples
105 int size; ///< audio buffer size
106 uint32_t sample_rate; ///< audio buffer sample rate
107 int planar; ///< audio buffer - planar or packed
108 } AVFilterBufferRefAudioProps;
109
110 /**
111 * Video specific properties in a reference to an AVFilterBuffer. Since
112 * AVFilterBufferRef is common to different media formats, video specific
113 * per reference properties must be separated out.
114 */
115 typedef struct AVFilterBufferRefVideoProps {
116 int w; ///< image width
117 int h; ///< image height
118 AVRational pixel_aspect; ///< pixel aspect ratio
119 int interlaced; ///< is frame interlaced
120 int top_field_first; ///< field order
121 enum AVPictureType pict_type; ///< picture type of the frame
122 int key_frame; ///< 1 -> keyframe, 0-> not
123 } AVFilterBufferRefVideoProps;
124
125 /**
126 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
127 * a buffer to, for example, crop image without any memcpy, the buffer origin
128 * and dimensions are per-reference properties. Linesize is also useful for
129 * image flipping, frame to field filters, etc, and so is also per-reference.
130 *
131 * TODO: add anything necessary for frame reordering
132 */
133 typedef struct AVFilterBufferRef {
134 AVFilterBuffer *buf; ///< the buffer that this is a reference to
135 uint8_t *data[8]; ///< picture/audio data for each plane
136 int linesize[8]; ///< number of bytes per line
137 int format; ///< media format
138
139 /**
140 * presentation timestamp. The time unit may change during
141 * filtering, as it is specified in the link and the filter code
142 * may need to rescale the PTS accordingly.
143 */
144 int64_t pts;
145 int64_t pos; ///< byte position in stream, -1 if unknown
146
147 int perms; ///< permissions, see the AV_PERM_* flags
148
149 enum AVMediaType type; ///< media type of buffer data
150 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
151 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
152 } AVFilterBufferRef;
153
154 /**
155 * Copy properties of src to dst, without copying the actual data
156 */
157 static inline void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src)
158 {
159 // copy common properties
160 dst->pts = src->pts;
161 dst->pos = src->pos;
162
163 switch (src->type) {
164 case AVMEDIA_TYPE_VIDEO: *dst->video = *src->video; break;
165 case AVMEDIA_TYPE_AUDIO: *dst->audio = *src->audio; break;
166 }
167 }
168
169 /**
170 * Add a new reference to a buffer.
171 *
172 * @param ref an existing reference to the buffer
173 * @param pmask a bitmask containing the allowable permissions in the new
174 * reference
175 * @return a new reference to the buffer with the same properties as the
176 * old, excluding any permissions denied by pmask
177 */
178 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
179
180 /**
181 * Remove a reference to a buffer. If this is the last reference to the
182 * buffer, the buffer itself is also automatically freed.
183 *
184 * @param ref reference to the buffer, may be NULL
185 */
186 void avfilter_unref_buffer(AVFilterBufferRef *ref);
187
188 /**
189 * A list of supported formats for one end of a filter link. This is used
190 * during the format negotiation process to try to pick the best format to
191 * use to minimize the number of necessary conversions. Each filter gives a
192 * list of the formats supported by each input and output pad. The list
193 * given for each pad need not be distinct - they may be references to the
194 * same list of formats, as is often the case when a filter supports multiple
195 * formats, but will always output the same format as it is given in input.
196 *
197 * In this way, a list of possible input formats and a list of possible
198 * output formats are associated with each link. When a set of formats is
199 * negotiated over a link, the input and output lists are merged to form a
200 * new list containing only the common elements of each list. In the case
201 * that there were no common elements, a format conversion is necessary.
202 * Otherwise, the lists are merged, and all other links which reference
203 * either of the format lists involved in the merge are also affected.
204 *
205 * For example, consider the filter chain:
206 * filter (a) --> (b) filter (b) --> (c) filter
207 *
208 * where the letters in parenthesis indicate a list of formats supported on
209 * the input or output of the link. Suppose the lists are as follows:
210 * (a) = {A, B}
211 * (b) = {A, B, C}
212 * (c) = {B, C}
213 *
214 * First, the first link's lists are merged, yielding:
215 * filter (a) --> (a) filter (a) --> (c) filter
216 *
217 * Notice that format list (b) now refers to the same list as filter list (a).
218 * Next, the lists for the second link are merged, yielding:
219 * filter (a) --> (a) filter (a) --> (a) filter
220 *
221 * where (a) = {B}.
222 *
223 * Unfortunately, when the format lists at the two ends of a link are merged,
224 * we must ensure that all links which reference either pre-merge format list
225 * get updated as well. Therefore, we have the format list structure store a
226 * pointer to each of the pointers to itself.
227 */
228 typedef struct AVFilterFormats {
229 unsigned format_count; ///< number of formats
230 int *formats; ///< list of media formats
231
232 unsigned refcount; ///< number of references to this list
233 struct AVFilterFormats ***refs; ///< references to this list
234 } AVFilterFormats;
235
236 /**
237 * Create a list of supported formats. This is intended for use in
238 * AVFilter->query_formats().
239 *
240 * @param fmts list of media formats, terminated by -1
241 * @return the format list, with no existing references
242 */
243 AVFilterFormats *avfilter_make_format_list(const int *fmts);
244
245 /**
246 * Add fmt to the list of media formats contained in *avff.
247 * If *avff is NULL the function allocates the filter formats struct
248 * and puts its pointer in *avff.
249 *
250 * @return a non negative value in case of success, or a negative
251 * value corresponding to an AVERROR code in case of error
252 */
253 int avfilter_add_format(AVFilterFormats **avff, int fmt);
254
255 /**
256 * Return a list of all formats supported by Libav for the given media type.
257 */
258 AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
259
260 /**
261 * Return a format list which contains the intersection of the formats of
262 * a and b. Also, all the references of a, all the references of b, and
263 * a and b themselves will be deallocated.
264 *
265 * If a and b do not share any common formats, neither is modified, and NULL
266 * is returned.
267 */
268 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
269
270 /**
271 * Add *ref as a new reference to formats.
272 * That is the pointers will point like in the ascii art below:
273 * ________
274 * |formats |<--------.
275 * | ____ | ____|___________________
276 * | |refs| | | __|_
277 * | |* * | | | | | | AVFilterLink
278 * | |* *--------->|*ref|
279 * | |____| | | |____|
280 * |________| |________________________
281 */
282 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
283
284 /**
285 * If *ref is non-NULL, remove *ref as a reference to the format list
286 * it currently points to, deallocates that list if this was the last
287 * reference, and sets *ref to NULL.
288 *
289 * Before After
290 * ________ ________ NULL
291 * |formats |<--------. |formats | ^
292 * | ____ | ____|________________ | ____ | ____|________________
293 * | |refs| | | __|_ | |refs| | | __|_
294 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
295 * | |* *--------->|*ref| | |* | | | |*ref|
296 * | |____| | | |____| | |____| | | |____|
297 * |________| |_____________________ |________| |_____________________
298 */
299 void avfilter_formats_unref(AVFilterFormats **ref);
300
301 /**
302 *
303 * Before After
304 * ________ ________
305 * |formats |<---------. |formats |<---------.
306 * | ____ | ___|___ | ____ | ___|___
307 * | |refs| | | | | | |refs| | | | | NULL
308 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
309 * | |* * | | |_______| | |* * | | |_______| ___|___
310 * | |____| | | |____| | | | |
311 * |________| |________| |*oldref|
312 * |_______|
313 */
314 void avfilter_formats_changeref(AVFilterFormats **oldref,
315 AVFilterFormats **newref);
316
317 /**
318 * A filter pad used for either input or output.
319 */
320 struct AVFilterPad {
321 /**
322 * Pad name. The name is unique among inputs and among outputs, but an
323 * input may have the same name as an output. This may be NULL if this
324 * pad has no need to ever be referenced by name.
325 */
326 const char *name;
327
328 /**
329 * AVFilterPad type. Only video supported now, hopefully someone will
330 * add audio in the future.
331 */
332 enum AVMediaType type;
333
334 /**
335 * Minimum required permissions on incoming buffers. Any buffer with
336 * insufficient permissions will be automatically copied by the filter
337 * system to a new buffer which provides the needed access permissions.
338 *
339 * Input pads only.
340 */
341 int min_perms;
342
343 /**
344 * Permissions which are not accepted on incoming buffers. Any buffer
345 * which has any of these permissions set will be automatically copied
346 * by the filter system to a new buffer which does not have those
347 * permissions. This can be used to easily disallow buffers with
348 * AV_PERM_REUSE.
349 *
350 * Input pads only.
351 */
352 int rej_perms;
353
354 /**
355 * Callback called before passing the first slice of a new frame. If
356 * NULL, the filter layer will default to storing a reference to the
357 * picture inside the link structure.
358 *
359 * Input video pads only.
360 */
361 void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
362
363 /**
364 * Callback function to get a video buffer. If NULL, the filter system will
365 * use avfilter_default_get_video_buffer().
366 *
367 * Input video pads only.
368 */
369 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
370
371 /**
372 * Callback function to get an audio buffer. If NULL, the filter system will
373 * use avfilter_default_get_audio_buffer().
374 *
375 * Input audio pads only.
376 */
377 AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms,
378 enum AVSampleFormat sample_fmt, int size,
379 int64_t channel_layout, int planar);
380
381 /**
382 * Callback called after the slices of a frame are completely sent. If
383 * NULL, the filter layer will default to releasing the reference stored
384 * in the link structure during start_frame().
385 *
386 * Input video pads only.
387 */
388 void (*end_frame)(AVFilterLink *link);
389
390 /**
391 * Slice drawing callback. This is where a filter receives video data
392 * and should do its processing.
393 *
394 * Input video pads only.
395 */
396 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
397
398 /**
399 * Samples filtering callback. This is where a filter receives audio data
400 * and should do its processing.
401 *
402 * Input audio pads only.
403 */
404 void (*filter_samples)(AVFilterLink *link, AVFilterBufferRef *samplesref);
405
406 /**
407 * Frame poll callback. This returns the number of immediately available
408 * samples. It should return a positive value if the next request_frame()
409 * is guaranteed to return one frame (with no delay).
410 *
411 * Defaults to just calling the source poll_frame() method.
412 *
413 * Output video pads only.
414 */
415 int (*poll_frame)(AVFilterLink *link);
416
417 /**
418 * Frame request callback. A call to this should result in at least one
419 * frame being output over the given link. This should return zero on
420 * success, and another value on error.
421 *
422 * Output video pads only.
423 */
424 int (*request_frame)(AVFilterLink *link);
425
426 /**
427 * Link configuration callback.
428 *
429 * For output pads, this should set the link properties such as
430 * width/height. This should NOT set the format property - that is
431 * negotiated between filters by the filter system using the
432 * query_formats() callback before this function is called.
433 *
434 * For input pads, this should check the properties of the link, and update
435 * the filter's internal state as necessary.
436 *
437 * For both input and output filters, this should return zero on success,
438 * and another value on error.
439 */
440 int (*config_props)(AVFilterLink *link);
441 };
442
443 /** default handler for start_frame() for video inputs */
444 void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
445
446 /** default handler for draw_slice() for video inputs */
447 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
448
449 /** default handler for end_frame() for video inputs */
450 void avfilter_default_end_frame(AVFilterLink *link);
451
452 /** default handler for filter_samples() for audio inputs */
453 void avfilter_default_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
454
455 /** default handler for config_props() for audio/video outputs */
456 int avfilter_default_config_output_link(AVFilterLink *link);
457
458 /** default handler for config_props() for audio/video inputs */
459 int avfilter_default_config_input_link (AVFilterLink *link);
460
461 /** default handler for get_video_buffer() for video inputs */
462 AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,
463 int perms, int w, int h);
464
465 /** default handler for get_audio_buffer() for audio inputs */
466 AVFilterBufferRef *avfilter_default_get_audio_buffer(AVFilterLink *link, int perms,
467 enum AVSampleFormat sample_fmt, int size,
468 int64_t channel_layout, int planar);
469
470 /**
471 * A helper for query_formats() which sets all links to the same list of
472 * formats. If there are no links hooked to this filter, the list of formats is
473 * freed.
474 */
475 void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
476
477 /** Default handler for query_formats() */
478 int avfilter_default_query_formats(AVFilterContext *ctx);
479
480 /** start_frame() handler for filters which simply pass video along */
481 void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
482
483 /** draw_slice() handler for filters which simply pass video along */
484 void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
485
486 /** end_frame() handler for filters which simply pass video along */
487 void avfilter_null_end_frame(AVFilterLink *link);
488
489 /** filter_samples() handler for filters which simply pass audio along */
490 void avfilter_null_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
491
492 /** get_video_buffer() handler for filters which simply pass video along */
493 AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link,
494 int perms, int w, int h);
495
496 /** get_audio_buffer() handler for filters which simply pass audio along */
497 AVFilterBufferRef *avfilter_null_get_audio_buffer(AVFilterLink *link, int perms,
498 enum AVSampleFormat sample_fmt, int size,
499 int64_t channel_layout, int planar);
500
501 /**
502 * Filter definition. This defines the pads a filter contains, and all the
503 * callback functions used to interact with the filter.
504 */
505 typedef struct AVFilter {
506 const char *name; ///< filter name
507
508 int priv_size; ///< size of private data to allocate for the filter
509
510 /**
511 * Filter initialization function. Args contains the user-supplied
512 * parameters. FIXME: maybe an AVOption-based system would be better?
513 * opaque is data provided by the code requesting creation of the filter,
514 * and is used to pass data to the filter.
515 */
516 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
517
518 /**
519 * Filter uninitialization function. Should deallocate any memory held
520 * by the filter, release any buffer references, etc. This does not need
521 * to deallocate the AVFilterContext->priv memory itself.
522 */
523 void (*uninit)(AVFilterContext *ctx);
524
525 /**
526 * Queries formats supported by the filter and its pads, and sets the
527 * in_formats for links connected to its output pads, and out_formats
528 * for links connected to its input pads.
529 *
530 * @return zero on success, a negative value corresponding to an
531 * AVERROR code otherwise
532 */
533 int (*query_formats)(AVFilterContext *);
534
535 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
536 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
537
538 /**
539 * A description for the filter. You should use the
540 * NULL_IF_CONFIG_SMALL() macro to define it.
541 */
542 const char *description;
543 } AVFilter;
544
545 /** An instance of a filter */
546 struct AVFilterContext {
547 const AVClass *av_class; ///< needed for av_log()
548
549 AVFilter *filter; ///< the AVFilter of which this is an instance
550
551 char *name; ///< name of this filter instance
552
553 unsigned input_count; ///< number of input pads
554 AVFilterPad *input_pads; ///< array of input pads
555 AVFilterLink **inputs; ///< array of pointers to input links
556
557 unsigned output_count; ///< number of output pads
558 AVFilterPad *output_pads; ///< array of output pads
559 AVFilterLink **outputs; ///< array of pointers to output links
560
561 void *priv; ///< private data for use by the filter
562 };
563
564 /**
565 * A link between two filters. This contains pointers to the source and
566 * destination filters between which this link exists, and the indexes of
567 * the pads involved. In addition, this link also contains the parameters
568 * which have been negotiated and agreed upon between the filter, such as
569 * image dimensions, format, etc.
570 */
571 struct AVFilterLink {
572 AVFilterContext *src; ///< source filter
573 AVFilterPad *srcpad; ///< output pad on the source filter
574
575 AVFilterContext *dst; ///< dest filter
576 AVFilterPad *dstpad; ///< input pad on the dest filter
577
578 /** stage of the initialization of the link properties (dimensions, etc) */
579 enum {
580 AVLINK_UNINIT = 0, ///< not started
581 AVLINK_STARTINIT, ///< started, but incomplete
582 AVLINK_INIT ///< complete
583 } init_state;
584
585 enum AVMediaType type; ///< filter media type
586
587 /* These parameters apply only to video */
588 int w; ///< agreed upon image width
589 int h; ///< agreed upon image height
590 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
591 /* These two parameters apply only to audio */
592 int64_t channel_layout; ///< channel layout of current buffer (see libavutil/audioconvert.h)
593 int64_t sample_rate; ///< samples per second
594
595 int format; ///< agreed upon media format
596
597 /**
598 * Lists of formats supported by the input and output filters respectively.
599 * These lists are used for negotiating the format to actually be used,
600 * which will be loaded into the format member, above, when chosen.
601 */
602 AVFilterFormats *in_formats;
603 AVFilterFormats *out_formats;
604
605 /**
606 * The buffer reference currently being sent across the link by the source
607 * filter. This is used internally by the filter system to allow
608 * automatic copying of buffers which do not have sufficient permissions
609 * for the destination. This should not be accessed directly by the
610 * filters.
611 */
612 AVFilterBufferRef *src_buf;
613
614 AVFilterBufferRef *cur_buf;
615 AVFilterBufferRef *out_buf;
616
617 /**
618 * Define the time base used by the PTS of the frames/samples
619 * which will pass through this link.
620 * During the configuration stage, each filter is supposed to
621 * change only the output timebase, while the timebase of the
622 * input link is assumed to be an unchangeable property.
623 */
624 AVRational time_base;
625 };
626
627 /**
628 * Link two filters together.
629 *
630 * @param src the source filter
631 * @param srcpad index of the output pad on the source filter
632 * @param dst the destination filter
633 * @param dstpad index of the input pad on the destination filter
634 * @return zero on success
635 */
636 int avfilter_link(AVFilterContext *src, unsigned srcpad,
637 AVFilterContext *dst, unsigned dstpad);
638
639 /**
640 * Negotiate the media format, dimensions, etc of all inputs to a filter.
641 *
642 * @param filter the filter to negotiate the properties for its inputs
643 * @return zero on successful negotiation
644 */
645 int avfilter_config_links(AVFilterContext *filter);
646
647 /**
648 * Request a picture buffer with a specific set of permissions.
649 *
650 * @param link the output link to the filter from which the buffer will
651 * be requested
652 * @param perms the required access permissions
653 * @param w the minimum width of the buffer to allocate
654 * @param h the minimum height of the buffer to allocate
655 * @return A reference to the buffer. This must be unreferenced with
656 * avfilter_unref_buffer when you are finished with it.
657 */
658 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
659 int w, int h);
660
661 /**
662 * Create a buffer reference wrapped around an already allocated image
663 * buffer.
664 *
665 * @param data pointers to the planes of the image to reference
666 * @param linesize linesizes for the planes of the image to reference
667 * @param perms the required access permissions
668 * @param w the width of the image specified by the data and linesize arrays
669 * @param h the height of the image specified by the data and linesize arrays
670 * @param format the pixel format of the image specified by the data and linesize arrays
671 */
672 AVFilterBufferRef *
673 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
674 int w, int h, enum PixelFormat format);
675
676 /**
677 * Request an audio samples buffer with a specific set of permissions.
678 *
679 * @param link the output link to the filter from which the buffer will
680 * be requested
681 * @param perms the required access permissions
682 * @param sample_fmt the format of each sample in the buffer to allocate
683 * @param size the buffer size in bytes
684 * @param channel_layout the number and type of channels per sample in the buffer to allocate
685 * @param planar audio data layout - planar or packed
686 * @return A reference to the samples. This must be unreferenced with
687 * avfilter_unref_buffer when you are finished with it.
688 */
689 AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms,
690 enum AVSampleFormat sample_fmt, int size,
691 int64_t channel_layout, int planar);
692
693 /**
694 * Request an input frame from the filter at the other end of the link.
695 *
696 * @param link the input link
697 * @return zero on success
698 */
699 int avfilter_request_frame(AVFilterLink *link);
700
701 /**
702 * Poll a frame from the filter chain.
703 *
704 * @param link the input link
705 * @return the number of immediately available frames, a negative
706 * number in case of error
707 */
708 int avfilter_poll_frame(AVFilterLink *link);
709
710 /**
711 * Notifie the next filter of the start of a frame.
712 *
713 * @param link the output link the frame will be sent over
714 * @param picref A reference to the frame about to be sent. The data for this
715 * frame need only be valid once draw_slice() is called for that
716 * portion. The receiving filter will free this reference when
717 * it no longer needs it.
718 */
719 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
720
721 /**
722 * Notifie the next filter that the current frame has finished.
723 *
724 * @param link the output link the frame was sent over
725 */
726 void avfilter_end_frame(AVFilterLink *link);
727
728 /**
729 * Send a slice to the next filter.
730 *
731 * Slices have to be provided in sequential order, either in
732 * top-bottom or bottom-top order. If slices are provided in
733 * non-sequential order the behavior of the function is undefined.
734 *
735 * @param link the output link over which the frame is being sent
736 * @param y offset in pixels from the top of the image for this slice
737 * @param h height of this slice in pixels
738 * @param slice_dir the assumed direction for sending slices,
739 * from the top slice to the bottom slice if the value is 1,
740 * from the bottom slice to the top slice if the value is -1,
741 * for other values the behavior of the function is undefined.
742 */
743 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
744
745 /**
746 * Send a buffer of audio samples to the next filter.
747 *
748 * @param link the output link over which the audio samples are being sent
749 * @param samplesref a reference to the buffer of audio samples being sent. The
750 * receiving filter will free this reference when it no longer
751 * needs it or pass it on to the next filter.
752 */
753 void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
754
755 /** Initialize the filter system. Register all builtin filters. */
756 void avfilter_register_all(void);
757
758 /** Uninitialize the filter system. Unregister all filters. */
759 void avfilter_uninit(void);
760
761 /**
762 * Register a filter. This is only needed if you plan to use
763 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
764 * filter can still by instantiated with avfilter_open even if it is not
765 * registered.
766 *
767 * @param filter the filter to register
768 * @return 0 if the registration was succesfull, a negative value
769 * otherwise
770 */
771 int avfilter_register(AVFilter *filter);
772
773 /**
774 * Get a filter definition matching the given name.
775 *
776 * @param name the filter name to find
777 * @return the filter definition, if any matching one is registered.
778 * NULL if none found.
779 */
780 AVFilter *avfilter_get_by_name(const char *name);
781
782 /**
783 * If filter is NULL, returns a pointer to the first registered filter pointer,
784 * if filter is non-NULL, returns the next pointer after filter.
785 * If the returned pointer points to NULL, the last registered filter
786 * was already reached.
787 */
788 AVFilter **av_filter_next(AVFilter **filter);
789
790 /**
791 * Create a filter instance.
792 *
793 * @param filter_ctx put here a pointer to the created filter context
794 * on success, NULL on failure
795 * @param filter the filter to create an instance of
796 * @param inst_name Name to give to the new instance. Can be NULL for none.
797 * @return >= 0 in case of success, a negative error code otherwise
798 */
799 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
800
801 /**
802 * Initialize a filter.
803 *
804 * @param filter the filter to initialize
805 * @param args A string of parameters to use when initializing the filter.
806 * The format and meaning of this string varies by filter.
807 * @param opaque Any extra non-string data needed by the filter. The meaning
808 * of this parameter varies by filter.
809 * @return zero on success
810 */
811 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
812
813 /**
814 * Free a filter context.
815 *
816 * @param filter the filter to free
817 */
818 void avfilter_free(AVFilterContext *filter);
819
820 /**
821 * Insert a filter in the middle of an existing link.
822 *
823 * @param link the link into which the filter should be inserted
824 * @param filt the filter to be inserted
825 * @param filt_srcpad_idx the input pad on the filter to connect
826 * @param filt_dstpad_idx the output pad on the filter to connect
827 * @return zero on success
828 */
829 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
830 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
831
832 /**
833 * Insert a new pad.
834 *
835 * @param idx Insertion point. Pad is inserted at the end if this point
836 * is beyond the end of the list of pads.
837 * @param count Pointer to the number of pads in the list
838 * @param padidx_off Offset within an AVFilterLink structure to the element
839 * to increment when inserting a new pad causes link
840 * numbering to change
841 * @param pads Pointer to the pointer to the beginning of the list of pads
842 * @param links Pointer to the pointer to the beginning of the list of links
843 * @param newpad The new pad to add. A copy is made when adding.
844 */
845 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
846 AVFilterPad **pads, AVFilterLink ***links,
847 AVFilterPad *newpad);
848
849 /** Insert a new input pad for the filter. */
850 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
851 AVFilterPad *p)
852 {
853 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
854 &f->input_pads, &f->inputs, p);
855 }
856
857 /** Insert a new output pad for the filter. */
858 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
859 AVFilterPad *p)
860 {
861 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
862 &f->output_pads, &f->outputs, p);
863 }
864
865 #endif /* AVFILTER_AVFILTER_H */