70efc5cd3cc1b3c372fd5ceb93b99ada94e797a9
[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 #include "libavcodec/avcodec.h"
31
32 #define LIBAVFILTER_VERSION_MAJOR 2
33 #define LIBAVFILTER_VERSION_MINOR 14
34 #define LIBAVFILTER_VERSION_MICRO 0
35
36 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
37 LIBAVFILTER_VERSION_MINOR, \
38 LIBAVFILTER_VERSION_MICRO)
39 #define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
40 LIBAVFILTER_VERSION_MINOR, \
41 LIBAVFILTER_VERSION_MICRO)
42 #define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
43
44 #include <stddef.h>
45
46 /**
47 * Return the LIBAVFILTER_VERSION_INT constant.
48 */
49 unsigned avfilter_version(void);
50
51 /**
52 * Return the libavfilter build-time configuration.
53 */
54 const char *avfilter_configuration(void);
55
56 /**
57 * Return the libavfilter license.
58 */
59 const char *avfilter_license(void);
60
61
62 typedef struct AVFilterContext AVFilterContext;
63 typedef struct AVFilterLink AVFilterLink;
64 typedef struct AVFilterPad AVFilterPad;
65
66 /**
67 * A reference-counted buffer data type used by the filter system. Filters
68 * should not store pointers to this structure directly, but instead use the
69 * AVFilterBufferRef structure below.
70 */
71 typedef struct AVFilterBuffer {
72 uint8_t *data[8]; ///< buffer data for each plane/channel
73 int linesize[8]; ///< number of bytes per line
74
75 unsigned refcount; ///< number of references to this buffer
76
77 /** private data to be used by a custom free function */
78 void *priv;
79 /**
80 * A pointer to the function to deallocate this buffer if the default
81 * function is not sufficient. This could, for example, add the memory
82 * back into a memory pool to be reused later without the overhead of
83 * reallocating it from scratch.
84 */
85 void (*free)(struct AVFilterBuffer *buf);
86
87 int format; ///< media format
88 int w, h; ///< width and height of the allocated buffer
89 } AVFilterBuffer;
90
91 #define AV_PERM_READ 0x01 ///< can read from the buffer
92 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
93 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
94 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
95 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
96 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
97
98 /**
99 * Audio specific properties in a reference to an AVFilterBuffer. Since
100 * AVFilterBufferRef is common to different media formats, audio specific
101 * per reference properties must be separated out.
102 */
103 typedef struct AVFilterBufferRefAudioProps {
104 uint64_t channel_layout; ///< channel layout of audio buffer
105 int nb_samples; ///< number of audio samples
106 int size; ///< audio buffer size
107 uint32_t sample_rate; ///< audio buffer sample rate
108 int planar; ///< audio buffer - planar or packed
109 } AVFilterBufferRefAudioProps;
110
111 /**
112 * Video specific properties in a reference to an AVFilterBuffer. Since
113 * AVFilterBufferRef is common to different media formats, video specific
114 * per reference properties must be separated out.
115 */
116 typedef struct AVFilterBufferRefVideoProps {
117 int w; ///< image width
118 int h; ///< image height
119 AVRational pixel_aspect; ///< pixel aspect ratio
120 int interlaced; ///< is frame interlaced
121 int top_field_first; ///< field order
122 enum AVPictureType pict_type; ///< picture type of the frame
123 int key_frame; ///< 1 -> keyframe, 0-> not
124 } AVFilterBufferRefVideoProps;
125
126 /**
127 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
128 * a buffer to, for example, crop image without any memcpy, the buffer origin
129 * and dimensions are per-reference properties. Linesize is also useful for
130 * image flipping, frame to field filters, etc, and so is also per-reference.
131 *
132 * TODO: add anything necessary for frame reordering
133 */
134 typedef struct AVFilterBufferRef {
135 AVFilterBuffer *buf; ///< the buffer that this is a reference to
136 uint8_t *data[8]; ///< picture/audio data for each plane
137 int linesize[8]; ///< number of bytes per line
138 int format; ///< media format
139
140 /**
141 * presentation timestamp. The time unit may change during
142 * filtering, as it is specified in the link and the filter code
143 * may need to rescale the PTS accordingly.
144 */
145 int64_t pts;
146 int64_t pos; ///< byte position in stream, -1 if unknown
147
148 int perms; ///< permissions, see the AV_PERM_* flags
149
150 enum AVMediaType type; ///< media type of buffer data
151 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
152 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
153 } AVFilterBufferRef;
154
155 /**
156 * Copy properties of src to dst, without copying the actual data
157 */
158 static inline void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src)
159 {
160 // copy common properties
161 dst->pts = src->pts;
162 dst->pos = src->pos;
163
164 switch (src->type) {
165 case AVMEDIA_TYPE_VIDEO: *dst->video = *src->video; break;
166 case AVMEDIA_TYPE_AUDIO: *dst->audio = *src->audio; break;
167 }
168 }
169
170 /**
171 * Add a new reference to a buffer.
172 *
173 * @param ref an existing reference to the buffer
174 * @param pmask a bitmask containing the allowable permissions in the new
175 * reference
176 * @return a new reference to the buffer with the same properties as the
177 * old, excluding any permissions denied by pmask
178 */
179 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
180
181 /**
182 * Remove a reference to a buffer. If this is the last reference to the
183 * buffer, the buffer itself is also automatically freed.
184 *
185 * @param ref reference to the buffer, may be NULL
186 */
187 void avfilter_unref_buffer(AVFilterBufferRef *ref);
188
189 /**
190 * A list of supported formats for one end of a filter link. This is used
191 * during the format negotiation process to try to pick the best format to
192 * use to minimize the number of necessary conversions. Each filter gives a
193 * list of the formats supported by each input and output pad. The list
194 * given for each pad need not be distinct - they may be references to the
195 * same list of formats, as is often the case when a filter supports multiple
196 * formats, but will always output the same format as it is given in input.
197 *
198 * In this way, a list of possible input formats and a list of possible
199 * output formats are associated with each link. When a set of formats is
200 * negotiated over a link, the input and output lists are merged to form a
201 * new list containing only the common elements of each list. In the case
202 * that there were no common elements, a format conversion is necessary.
203 * Otherwise, the lists are merged, and all other links which reference
204 * either of the format lists involved in the merge are also affected.
205 *
206 * For example, consider the filter chain:
207 * filter (a) --> (b) filter (b) --> (c) filter
208 *
209 * where the letters in parenthesis indicate a list of formats supported on
210 * the input or output of the link. Suppose the lists are as follows:
211 * (a) = {A, B}
212 * (b) = {A, B, C}
213 * (c) = {B, C}
214 *
215 * First, the first link's lists are merged, yielding:
216 * filter (a) --> (a) filter (a) --> (c) filter
217 *
218 * Notice that format list (b) now refers to the same list as filter list (a).
219 * Next, the lists for the second link are merged, yielding:
220 * filter (a) --> (a) filter (a) --> (a) filter
221 *
222 * where (a) = {B}.
223 *
224 * Unfortunately, when the format lists at the two ends of a link are merged,
225 * we must ensure that all links which reference either pre-merge format list
226 * get updated as well. Therefore, we have the format list structure store a
227 * pointer to each of the pointers to itself.
228 */
229 typedef struct AVFilterFormats {
230 unsigned format_count; ///< number of formats
231 int *formats; ///< list of media formats
232
233 unsigned refcount; ///< number of references to this list
234 struct AVFilterFormats ***refs; ///< references to this list
235 } AVFilterFormats;
236
237 /**
238 * Create a list of supported formats. This is intended for use in
239 * AVFilter->query_formats().
240 *
241 * @param fmts list of media formats, terminated by -1
242 * @return the format list, with no existing references
243 */
244 AVFilterFormats *avfilter_make_format_list(const int *fmts);
245
246 /**
247 * Add fmt to the list of media formats contained in *avff.
248 * If *avff is NULL the function allocates the filter formats struct
249 * and puts its pointer in *avff.
250 *
251 * @return a non negative value in case of success, or a negative
252 * value corresponding to an AVERROR code in case of error
253 */
254 int avfilter_add_format(AVFilterFormats **avff, int fmt);
255
256 /**
257 * Return a list of all formats supported by Libav for the given media type.
258 */
259 AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
260
261 /**
262 * Return a format list which contains the intersection of the formats of
263 * a and b. Also, all the references of a, all the references of b, and
264 * a and b themselves will be deallocated.
265 *
266 * If a and b do not share any common formats, neither is modified, and NULL
267 * is returned.
268 */
269 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
270
271 /**
272 * Add *ref as a new reference to formats.
273 * That is the pointers will point like in the ascii art below:
274 * ________
275 * |formats |<--------.
276 * | ____ | ____|___________________
277 * | |refs| | | __|_
278 * | |* * | | | | | | AVFilterLink
279 * | |* *--------->|*ref|
280 * | |____| | | |____|
281 * |________| |________________________
282 */
283 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
284
285 /**
286 * If *ref is non-NULL, remove *ref as a reference to the format list
287 * it currently points to, deallocates that list if this was the last
288 * reference, and sets *ref to NULL.
289 *
290 * Before After
291 * ________ ________ NULL
292 * |formats |<--------. |formats | ^
293 * | ____ | ____|________________ | ____ | ____|________________
294 * | |refs| | | __|_ | |refs| | | __|_
295 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
296 * | |* *--------->|*ref| | |* | | | |*ref|
297 * | |____| | | |____| | |____| | | |____|
298 * |________| |_____________________ |________| |_____________________
299 */
300 void avfilter_formats_unref(AVFilterFormats **ref);
301
302 /**
303 *
304 * Before After
305 * ________ ________
306 * |formats |<---------. |formats |<---------.
307 * | ____ | ___|___ | ____ | ___|___
308 * | |refs| | | | | | |refs| | | | | NULL
309 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
310 * | |* * | | |_______| | |* * | | |_______| ___|___
311 * | |____| | | |____| | | | |
312 * |________| |________| |*oldref|
313 * |_______|
314 */
315 void avfilter_formats_changeref(AVFilterFormats **oldref,
316 AVFilterFormats **newref);
317
318 /**
319 * A filter pad used for either input or output.
320 */
321 struct AVFilterPad {
322 /**
323 * Pad name. The name is unique among inputs and among outputs, but an
324 * input may have the same name as an output. This may be NULL if this
325 * pad has no need to ever be referenced by name.
326 */
327 const char *name;
328
329 /**
330 * AVFilterPad type. Only video supported now, hopefully someone will
331 * add audio in the future.
332 */
333 enum AVMediaType type;
334
335 /**
336 * Minimum required permissions on incoming buffers. Any buffer with
337 * insufficient permissions will be automatically copied by the filter
338 * system to a new buffer which provides the needed access permissions.
339 *
340 * Input pads only.
341 */
342 int min_perms;
343
344 /**
345 * Permissions which are not accepted on incoming buffers. Any buffer
346 * which has any of these permissions set will be automatically copied
347 * by the filter system to a new buffer which does not have those
348 * permissions. This can be used to easily disallow buffers with
349 * AV_PERM_REUSE.
350 *
351 * Input pads only.
352 */
353 int rej_perms;
354
355 /**
356 * Callback called before passing the first slice of a new frame. If
357 * NULL, the filter layer will default to storing a reference to the
358 * picture inside the link structure.
359 *
360 * Input video pads only.
361 */
362 void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
363
364 /**
365 * Callback function to get a video buffer. If NULL, the filter system will
366 * use avfilter_default_get_video_buffer().
367 *
368 * Input video pads only.
369 */
370 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
371
372 /**
373 * Callback function to get an audio buffer. If NULL, the filter system will
374 * use avfilter_default_get_audio_buffer().
375 *
376 * Input audio pads only.
377 */
378 AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms,
379 enum AVSampleFormat sample_fmt, int size,
380 uint64_t channel_layout, int planar);
381
382 /**
383 * Callback called after the slices of a frame are completely sent. If
384 * NULL, the filter layer will default to releasing the reference stored
385 * in the link structure during start_frame().
386 *
387 * Input video pads only.
388 */
389 void (*end_frame)(AVFilterLink *link);
390
391 /**
392 * Slice drawing callback. This is where a filter receives video data
393 * and should do its processing.
394 *
395 * Input video pads only.
396 */
397 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
398
399 /**
400 * Samples filtering callback. This is where a filter receives audio data
401 * and should do its processing.
402 *
403 * Input audio pads only.
404 */
405 void (*filter_samples)(AVFilterLink *link, AVFilterBufferRef *samplesref);
406
407 /**
408 * Frame poll callback. This returns the number of immediately available
409 * samples. It should return a positive value if the next request_frame()
410 * is guaranteed to return one frame (with no delay).
411 *
412 * Defaults to just calling the source poll_frame() method.
413 *
414 * Output video pads only.
415 */
416 int (*poll_frame)(AVFilterLink *link);
417
418 /**
419 * Frame request callback. A call to this should result in at least one
420 * frame being output over the given link. This should return zero on
421 * success, and another value on error.
422 *
423 * Output video pads only.
424 */
425 int (*request_frame)(AVFilterLink *link);
426
427 /**
428 * Link configuration callback.
429 *
430 * For output pads, this should set the link properties such as
431 * width/height. This should NOT set the format property - that is
432 * negotiated between filters by the filter system using the
433 * query_formats() callback before this function is called.
434 *
435 * For input pads, this should check the properties of the link, and update
436 * the filter's internal state as necessary.
437 *
438 * For both input and output filters, this should return zero on success,
439 * and another value on error.
440 */
441 int (*config_props)(AVFilterLink *link);
442 };
443
444 /** default handler for start_frame() for video inputs */
445 void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
446
447 /** default handler for draw_slice() for video inputs */
448 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
449
450 /** default handler for end_frame() for video inputs */
451 void avfilter_default_end_frame(AVFilterLink *link);
452
453 /** default handler for filter_samples() for audio inputs */
454 void avfilter_default_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
455
456 /** default handler for config_props() for audio/video outputs */
457 int avfilter_default_config_output_link(AVFilterLink *link);
458
459 /** default handler for config_props() for audio/video inputs */
460 int avfilter_default_config_input_link (AVFilterLink *link);
461
462 /** default handler for get_video_buffer() for video inputs */
463 AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,
464 int perms, int w, int h);
465
466 /** default handler for get_audio_buffer() for audio inputs */
467 AVFilterBufferRef *avfilter_default_get_audio_buffer(AVFilterLink *link, int perms,
468 enum AVSampleFormat sample_fmt, int size,
469 uint64_t channel_layout, int planar);
470
471 /**
472 * A helper for query_formats() which sets all links to the same list of
473 * formats. If there are no links hooked to this filter, the list of formats is
474 * freed.
475 */
476 void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
477
478 /** Default handler for query_formats() */
479 int avfilter_default_query_formats(AVFilterContext *ctx);
480
481 /** start_frame() handler for filters which simply pass video along */
482 void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
483
484 /** draw_slice() handler for filters which simply pass video along */
485 void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
486
487 /** end_frame() handler for filters which simply pass video along */
488 void avfilter_null_end_frame(AVFilterLink *link);
489
490 /** filter_samples() handler for filters which simply pass audio along */
491 void avfilter_null_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
492
493 /** get_video_buffer() handler for filters which simply pass video along */
494 AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link,
495 int perms, int w, int h);
496
497 /** get_audio_buffer() handler for filters which simply pass audio along */
498 AVFilterBufferRef *avfilter_null_get_audio_buffer(AVFilterLink *link, int perms,
499 enum AVSampleFormat sample_fmt, int size,
500 uint64_t channel_layout, int planar);
501
502 /**
503 * Filter definition. This defines the pads a filter contains, and all the
504 * callback functions used to interact with the filter.
505 */
506 typedef struct AVFilter {
507 const char *name; ///< filter name
508
509 int priv_size; ///< size of private data to allocate for the filter
510
511 /**
512 * Filter initialization function. Args contains the user-supplied
513 * parameters. FIXME: maybe an AVOption-based system would be better?
514 * opaque is data provided by the code requesting creation of the filter,
515 * and is used to pass data to the filter.
516 */
517 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
518
519 /**
520 * Filter uninitialization function. Should deallocate any memory held
521 * by the filter, release any buffer references, etc. This does not need
522 * to deallocate the AVFilterContext->priv memory itself.
523 */
524 void (*uninit)(AVFilterContext *ctx);
525
526 /**
527 * Queries formats supported by the filter and its pads, and sets the
528 * in_formats for links connected to its output pads, and out_formats
529 * for links connected to its input pads.
530 *
531 * @return zero on success, a negative value corresponding to an
532 * AVERROR code otherwise
533 */
534 int (*query_formats)(AVFilterContext *);
535
536 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
537 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
538
539 /**
540 * A description for the filter. You should use the
541 * NULL_IF_CONFIG_SMALL() macro to define it.
542 */
543 const char *description;
544 } AVFilter;
545
546 /** An instance of a filter */
547 struct AVFilterContext {
548 const AVClass *av_class; ///< needed for av_log()
549
550 AVFilter *filter; ///< the AVFilter of which this is an instance
551
552 char *name; ///< name of this filter instance
553
554 unsigned input_count; ///< number of input pads
555 AVFilterPad *input_pads; ///< array of input pads
556 AVFilterLink **inputs; ///< array of pointers to input links
557
558 unsigned output_count; ///< number of output pads
559 AVFilterPad *output_pads; ///< array of output pads
560 AVFilterLink **outputs; ///< array of pointers to output links
561
562 void *priv; ///< private data for use by the filter
563 };
564
565 /**
566 * A link between two filters. This contains pointers to the source and
567 * destination filters between which this link exists, and the indexes of
568 * the pads involved. In addition, this link also contains the parameters
569 * which have been negotiated and agreed upon between the filter, such as
570 * image dimensions, format, etc.
571 */
572 struct AVFilterLink {
573 AVFilterContext *src; ///< source filter
574 AVFilterPad *srcpad; ///< output pad on the source filter
575
576 AVFilterContext *dst; ///< dest filter
577 AVFilterPad *dstpad; ///< input pad on the dest filter
578
579 /** stage of the initialization of the link properties (dimensions, etc) */
580 enum {
581 AVLINK_UNINIT = 0, ///< not started
582 AVLINK_STARTINIT, ///< started, but incomplete
583 AVLINK_INIT ///< complete
584 } init_state;
585
586 enum AVMediaType type; ///< filter media type
587
588 /* These parameters apply only to video */
589 int w; ///< agreed upon image width
590 int h; ///< agreed upon image height
591 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
592 /* These two parameters apply only to audio */
593 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/audioconvert.h)
594 int64_t sample_rate; ///< samples per second
595
596 int format; ///< agreed upon media format
597
598 /**
599 * Lists of formats supported by the input and output filters respectively.
600 * These lists are used for negotiating the format to actually be used,
601 * which will be loaded into the format member, above, when chosen.
602 */
603 AVFilterFormats *in_formats;
604 AVFilterFormats *out_formats;
605
606 /**
607 * The buffer reference currently being sent across the link by the source
608 * filter. This is used internally by the filter system to allow
609 * automatic copying of buffers which do not have sufficient permissions
610 * for the destination. This should not be accessed directly by the
611 * filters.
612 */
613 AVFilterBufferRef *src_buf;
614
615 AVFilterBufferRef *cur_buf;
616 AVFilterBufferRef *out_buf;
617
618 /**
619 * Define the time base used by the PTS of the frames/samples
620 * which will pass through this link.
621 * During the configuration stage, each filter is supposed to
622 * change only the output timebase, while the timebase of the
623 * input link is assumed to be an unchangeable property.
624 */
625 AVRational time_base;
626 };
627
628 /**
629 * Link two filters together.
630 *
631 * @param src the source filter
632 * @param srcpad index of the output pad on the source filter
633 * @param dst the destination filter
634 * @param dstpad index of the input pad on the destination filter
635 * @return zero on success
636 */
637 int avfilter_link(AVFilterContext *src, unsigned srcpad,
638 AVFilterContext *dst, unsigned dstpad);
639
640 /**
641 * Negotiate the media format, dimensions, etc of all inputs to a filter.
642 *
643 * @param filter the filter to negotiate the properties for its inputs
644 * @return zero on successful negotiation
645 */
646 int avfilter_config_links(AVFilterContext *filter);
647
648 /**
649 * Request a picture buffer with a specific set of permissions.
650 *
651 * @param link the output link to the filter from which the buffer will
652 * be requested
653 * @param perms the required access permissions
654 * @param w the minimum width of the buffer to allocate
655 * @param h the minimum height of the buffer to allocate
656 * @return A reference to the buffer. This must be unreferenced with
657 * avfilter_unref_buffer when you are finished with it.
658 */
659 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
660 int w, int h);
661
662 /**
663 * Create a buffer reference wrapped around an already allocated image
664 * buffer.
665 *
666 * @param data pointers to the planes of the image to reference
667 * @param linesize linesizes for the planes of the image to reference
668 * @param perms the required access permissions
669 * @param w the width of the image specified by the data and linesize arrays
670 * @param h the height of the image specified by the data and linesize arrays
671 * @param format the pixel format of the image specified by the data and linesize arrays
672 */
673 AVFilterBufferRef *
674 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
675 int w, int h, enum PixelFormat format);
676
677 /**
678 * Request an audio samples buffer with a specific set of permissions.
679 *
680 * @param link the output link to the filter from which the buffer will
681 * be requested
682 * @param perms the required access permissions
683 * @param sample_fmt the format of each sample in the buffer to allocate
684 * @param size the buffer size in bytes
685 * @param channel_layout the number and type of channels per sample in the buffer to allocate
686 * @param planar audio data layout - planar or packed
687 * @return A reference to the samples. This must be unreferenced with
688 * avfilter_unref_buffer when you are finished with it.
689 */
690 AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms,
691 enum AVSampleFormat sample_fmt, int size,
692 uint64_t channel_layout, int planar);
693
694 /**
695 * Request an input frame from the filter at the other end of the link.
696 *
697 * @param link the input link
698 * @return zero on success
699 */
700 int avfilter_request_frame(AVFilterLink *link);
701
702 /**
703 * Poll a frame from the filter chain.
704 *
705 * @param link the input link
706 * @return the number of immediately available frames, a negative
707 * number in case of error
708 */
709 int avfilter_poll_frame(AVFilterLink *link);
710
711 /**
712 * Notify the next filter of the start of a frame.
713 *
714 * @param link the output link the frame will be sent over
715 * @param picref A reference to the frame about to be sent. The data for this
716 * frame need only be valid once draw_slice() is called for that
717 * portion. The receiving filter will free this reference when
718 * it no longer needs it.
719 */
720 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
721
722 /**
723 * Notifie the next filter that the current frame has finished.
724 *
725 * @param link the output link the frame was sent over
726 */
727 void avfilter_end_frame(AVFilterLink *link);
728
729 /**
730 * Send a slice to the next filter.
731 *
732 * Slices have to be provided in sequential order, either in
733 * top-bottom or bottom-top order. If slices are provided in
734 * non-sequential order the behavior of the function is undefined.
735 *
736 * @param link the output link over which the frame is being sent
737 * @param y offset in pixels from the top of the image for this slice
738 * @param h height of this slice in pixels
739 * @param slice_dir the assumed direction for sending slices,
740 * from the top slice to the bottom slice if the value is 1,
741 * from the bottom slice to the top slice if the value is -1,
742 * for other values the behavior of the function is undefined.
743 */
744 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
745
746 /**
747 * Send a buffer of audio samples to the next filter.
748 *
749 * @param link the output link over which the audio samples are being sent
750 * @param samplesref a reference to the buffer of audio samples being sent. The
751 * receiving filter will free this reference when it no longer
752 * needs it or pass it on to the next filter.
753 */
754 void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
755
756 /** Initialize the filter system. Register all builtin filters. */
757 void avfilter_register_all(void);
758
759 /** Uninitialize the filter system. Unregister all filters. */
760 void avfilter_uninit(void);
761
762 /**
763 * Register a filter. This is only needed if you plan to use
764 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
765 * filter can still by instantiated with avfilter_open even if it is not
766 * registered.
767 *
768 * @param filter the filter to register
769 * @return 0 if the registration was succesfull, a negative value
770 * otherwise
771 */
772 int avfilter_register(AVFilter *filter);
773
774 /**
775 * Get a filter definition matching the given name.
776 *
777 * @param name the filter name to find
778 * @return the filter definition, if any matching one is registered.
779 * NULL if none found.
780 */
781 AVFilter *avfilter_get_by_name(const char *name);
782
783 /**
784 * If filter is NULL, returns a pointer to the first registered filter pointer,
785 * if filter is non-NULL, returns the next pointer after filter.
786 * If the returned pointer points to NULL, the last registered filter
787 * was already reached.
788 */
789 AVFilter **av_filter_next(AVFilter **filter);
790
791 /**
792 * Create a filter instance.
793 *
794 * @param filter_ctx put here a pointer to the created filter context
795 * on success, NULL on failure
796 * @param filter the filter to create an instance of
797 * @param inst_name Name to give to the new instance. Can be NULL for none.
798 * @return >= 0 in case of success, a negative error code otherwise
799 */
800 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
801
802 /**
803 * Initialize a filter.
804 *
805 * @param filter the filter to initialize
806 * @param args A string of parameters to use when initializing the filter.
807 * The format and meaning of this string varies by filter.
808 * @param opaque Any extra non-string data needed by the filter. The meaning
809 * of this parameter varies by filter.
810 * @return zero on success
811 */
812 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
813
814 /**
815 * Free a filter context.
816 *
817 * @param filter the filter to free
818 */
819 void avfilter_free(AVFilterContext *filter);
820
821 /**
822 * Insert a filter in the middle of an existing link.
823 *
824 * @param link the link into which the filter should be inserted
825 * @param filt the filter to be inserted
826 * @param filt_srcpad_idx the input pad on the filter to connect
827 * @param filt_dstpad_idx the output pad on the filter to connect
828 * @return zero on success
829 */
830 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
831 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
832
833 /**
834 * Insert a new pad.
835 *
836 * @param idx Insertion point. Pad is inserted at the end if this point
837 * is beyond the end of the list of pads.
838 * @param count Pointer to the number of pads in the list
839 * @param padidx_off Offset within an AVFilterLink structure to the element
840 * to increment when inserting a new pad causes link
841 * numbering to change
842 * @param pads Pointer to the pointer to the beginning of the list of pads
843 * @param links Pointer to the pointer to the beginning of the list of links
844 * @param newpad The new pad to add. A copy is made when adding.
845 */
846 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
847 AVFilterPad **pads, AVFilterLink ***links,
848 AVFilterPad *newpad);
849
850 /** Insert a new input pad for the filter. */
851 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
852 AVFilterPad *p)
853 {
854 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
855 &f->input_pads, &f->inputs, p);
856 }
857
858 /** Insert a new output pad for the filter. */
859 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
860 AVFilterPad *p)
861 {
862 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
863 &f->output_pads, &f->outputs, p);
864 }
865
866 /**
867 * Copy the frame properties of src to dst, without copying the actual
868 * image data.
869 *
870 * @return 0 on success, a negative number on error.
871 */
872 int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src);
873
874 #endif /* AVFILTER_AVFILTER_H */