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