3 * copyright (c) 2007 Bobby Bingham
5 * This file is part of FFmpeg.
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.
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.
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
22 #ifndef AVFILTER_AVFILTER_H
23 #define AVFILTER_AVFILTER_H
25 #include "libavutil/avutil.h"
27 #define LIBAVFILTER_VERSION_MAJOR 1
28 #define LIBAVFILTER_VERSION_MINOR 29
29 #define LIBAVFILTER_VERSION_MICRO 0
31 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
32 LIBAVFILTER_VERSION_MINOR, \
33 LIBAVFILTER_VERSION_MICRO)
34 #define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
35 LIBAVFILTER_VERSION_MINOR, \
36 LIBAVFILTER_VERSION_MICRO)
37 #define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
40 #include "libavcodec/avcodec.h"
43 * Return the LIBAVFILTER_VERSION_INT constant.
45 unsigned avfilter_version(void);
48 * Return the libavfilter build-time configuration.
50 const char *avfilter_configuration(void);
53 * Return the libavfilter license.
55 const char *avfilter_license(void);
58 typedef struct AVFilterContext AVFilterContext;
59 typedef struct AVFilterLink AVFilterLink;
60 typedef struct AVFilterPad AVFilterPad;
63 * A reference-counted buffer data type used by the filter system. Filters
64 * should not store pointers to this structure directly, but instead use the
65 * AVFilterBufferRef structure below.
67 typedef struct AVFilterBuffer
69 uint8_t *data[8]; ///< buffer data for each plane/channel
70 int linesize[8]; ///< number of bytes per line
72 unsigned refcount; ///< number of references to this buffer
74 /** private data to be used by a custom free function */
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.
82 void (*free)(struct AVFilterBuffer *buf);
85 #define AV_PERM_READ 0x01 ///< can read from the buffer
86 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
87 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
88 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
89 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
92 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
93 * a picture to, for example, crop image without any memcpy, the picture origin
94 * and dimensions are per-reference properties. Linesize is also useful for
95 * image flipping, frame to field filters, etc, and so is also per-reference.
97 * TODO: add anything necessary for frame reordering
99 typedef struct AVFilterBufferRef
101 AVFilterBuffer *pic; ///< the picture that this is a reference to
102 uint8_t *data[4]; ///< picture data for each plane
103 int linesize[4]; ///< number of bytes per line
104 int w; ///< image width
105 int h; ///< image height
106 int format; ///< media format
108 int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
109 int64_t pos; ///< byte position in stream, -1 if unknown
111 AVRational pixel_aspect; ///< pixel aspect ratio
113 int perms; ///< permissions, see the AV_PERM_* flags
115 int interlaced; ///< is frame interlaced
120 * Copy properties of src to dst, without copying the actual video
123 static inline void avfilter_copy_picref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src)
127 dst->pixel_aspect = src->pixel_aspect;
128 dst->interlaced = src->interlaced;
129 dst->top_field_first = src->top_field_first;
135 * Add a new reference to a picture.
136 * @param ref an existing reference to the picture
137 * @param pmask a bitmask containing the allowable permissions in the new
139 * @return a new reference to the picture with the same properties as the
140 * old, excluding any permissions denied by pmask
142 AVFilterBufferRef *avfilter_ref_pic(AVFilterBufferRef *ref, int pmask);
145 * Remove a reference to a picture. If this is the last reference to the
146 * picture, the picture itself is also automatically freed.
147 * @param ref reference to the picture
149 void avfilter_unref_pic(AVFilterBufferRef *ref);
152 * A list of supported formats for one end of a filter link. This is used
153 * during the format negotiation process to try to pick the best format to
154 * use to minimize the number of necessary conversions. Each filter gives a
155 * list of the formats supported by each input and output pad. The list
156 * given for each pad need not be distinct - they may be references to the
157 * same list of formats, as is often the case when a filter supports multiple
158 * formats, but will always output the same format as it is given in input.
160 * In this way, a list of possible input formats and a list of possible
161 * output formats are associated with each link. When a set of formats is
162 * negotiated over a link, the input and output lists are merged to form a
163 * new list containing only the common elements of each list. In the case
164 * that there were no common elements, a format conversion is necessary.
165 * Otherwise, the lists are merged, and all other links which reference
166 * either of the format lists involved in the merge are also affected.
168 * For example, consider the filter chain:
169 * filter (a) --> (b) filter (b) --> (c) filter
171 * where the letters in parenthesis indicate a list of formats supported on
172 * the input or output of the link. Suppose the lists are as follows:
177 * First, the first link's lists are merged, yielding:
178 * filter (a) --> (a) filter (a) --> (c) filter
180 * Notice that format list (b) now refers to the same list as filter list (a).
181 * Next, the lists for the second link are merged, yielding:
182 * filter (a) --> (a) filter (a) --> (a) filter
186 * Unfortunately, when the format lists at the two ends of a link are merged,
187 * we must ensure that all links which reference either pre-merge format list
188 * get updated as well. Therefore, we have the format list structure store a
189 * pointer to each of the pointers to itself.
191 typedef struct AVFilterFormats AVFilterFormats;
192 struct AVFilterFormats
194 unsigned format_count; ///< number of formats
195 int *formats; ///< list of media formats
197 unsigned refcount; ///< number of references to this list
198 AVFilterFormats ***refs; ///< references to this list
202 * Create a list of supported formats. This is intended for use in
203 * AVFilter->query_formats().
204 * @param fmts list of media formats, terminated by -1
205 * @return the format list, with no existing references
207 AVFilterFormats *avfilter_make_format_list(const int *fmts);
210 * Add fmt to the list of media formats contained in *avff.
211 * If *avff is NULL the function allocates the filter formats struct
212 * and puts its pointer in *avff.
214 * @return a non negative value in case of success, or a negative
215 * value corresponding to an AVERROR code in case of error
217 int avfilter_add_format(AVFilterFormats **avff, int fmt);
220 * Return a list of all formats supported by FFmpeg for the given media type.
222 AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
225 * Return a format list which contains the intersection of the formats of
226 * a and b. Also, all the references of a, all the references of b, and
227 * a and b themselves will be deallocated.
229 * If a and b do not share any common formats, neither is modified, and NULL
232 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
235 * Add *ref as a new reference to formats.
236 * That is the pointers will point like in the ascii art below:
238 * |formats |<--------.
239 * | ____ | ____|___________________
241 * | |* * | | | | | | AVFilterLink
242 * | |* *--------->|*ref|
243 * | |____| | | |____|
244 * |________| |________________________
246 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
249 * If *ref is non-NULL, remove *ref as a reference to the format list
250 * it currently points to, deallocates that list if this was the last
251 * reference, and sets *ref to NULL.
254 * ________ ________ NULL
255 * |formats |<--------. |formats | ^
256 * | ____ | ____|________________ | ____ | ____|________________
257 * | |refs| | | __|_ | |refs| | | __|_
258 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
259 * | |* *--------->|*ref| | |* | | | |*ref|
260 * | |____| | | |____| | |____| | | |____|
261 * |________| |_____________________ |________| |_____________________
263 void avfilter_formats_unref(AVFilterFormats **ref);
269 * |formats |<---------. |formats |<---------.
270 * | ____ | ___|___ | ____ | ___|___
271 * | |refs| | | | | | |refs| | | | | NULL
272 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
273 * | |* * | | |_______| | |* * | | |_______| ___|___
274 * | |____| | | |____| | | | |
275 * |________| |________| |*oldref|
278 void avfilter_formats_changeref(AVFilterFormats **oldref,
279 AVFilterFormats **newref);
282 * A filter pad used for either input or output.
287 * Pad name. The name is unique among inputs and among outputs, but an
288 * input may have the same name as an output. This may be NULL if this
289 * pad has no need to ever be referenced by name.
294 * AVFilterPad type. Only video supported now, hopefully someone will
295 * add audio in the future.
297 enum AVMediaType type;
300 * Minimum required permissions on incoming buffers. Any buffer with
301 * insufficient permissions will be automatically copied by the filter
302 * system to a new buffer which provides the needed access permissions.
309 * Permissions which are not accepted on incoming buffers. Any buffer
310 * which has any of these permissions set will be automatically copied
311 * by the filter system to a new buffer which does not have those
312 * permissions. This can be used to easily disallow buffers with
320 * Callback called before passing the first slice of a new frame. If
321 * NULL, the filter layer will default to storing a reference to the
322 * picture inside the link structure.
324 * Input video pads only.
326 void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
329 * Callback function to get a buffer. If NULL, the filter system will
330 * use avfilter_default_get_video_buffer().
332 * Input video pads only.
334 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
337 * Callback called after the slices of a frame are completely sent. If
338 * NULL, the filter layer will default to releasing the reference stored
339 * in the link structure during start_frame().
341 * Input video pads only.
343 void (*end_frame)(AVFilterLink *link);
346 * Slice drawing callback. This is where a filter receives video data
347 * and should do its processing.
349 * Input video pads only.
351 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
354 * Frame poll callback. This returns the number of immediately available
355 * frames. It should return a positive value if the next request_frame()
356 * is guaranteed to return one frame (with no delay).
358 * Defaults to just calling the source poll_frame() method.
360 * Output video pads only.
362 int (*poll_frame)(AVFilterLink *link);
365 * Frame request callback. A call to this should result in at least one
366 * frame being output over the given link. This should return zero on
367 * success, and another value on error.
369 * Output video pads only.
371 int (*request_frame)(AVFilterLink *link);
374 * Link configuration callback.
376 * For output pads, this should set the link properties such as
377 * width/height. This should NOT set the format property - that is
378 * negotiated between filters by the filter system using the
379 * query_formats() callback before this function is called.
381 * For input pads, this should check the properties of the link, and update
382 * the filter's internal state as necessary.
384 * For both input and output filters, this should return zero on success,
385 * and another value on error.
387 int (*config_props)(AVFilterLink *link);
390 /** default handler for start_frame() for video inputs */
391 void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
392 /** default handler for draw_slice() for video inputs */
393 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
394 /** default handler for end_frame() for video inputs */
395 void avfilter_default_end_frame(AVFilterLink *link);
396 /** default handler for config_props() for video outputs */
397 int avfilter_default_config_output_link(AVFilterLink *link);
398 /** default handler for config_props() for video inputs */
399 int avfilter_default_config_input_link (AVFilterLink *link);
400 /** default handler for get_video_buffer() for video inputs */
401 AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,
402 int perms, int w, int h);
404 * A helper for query_formats() which sets all links to the same list of
405 * formats. If there are no links hooked to this filter, the list of formats is
408 void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
409 /** Default handler for query_formats() */
410 int avfilter_default_query_formats(AVFilterContext *ctx);
412 /** start_frame() handler for filters which simply pass video along */
413 void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
415 /** draw_slice() handler for filters which simply pass video along */
416 void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
418 /** end_frame() handler for filters which simply pass video along */
419 void avfilter_null_end_frame(AVFilterLink *link);
421 /** get_video_buffer() handler for filters which simply pass video along */
422 AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link,
423 int perms, int w, int h);
426 * Filter definition. This defines the pads a filter contains, and all the
427 * callback functions used to interact with the filter.
429 typedef struct AVFilter
431 const char *name; ///< filter name
433 int priv_size; ///< size of private data to allocate for the filter
436 * Filter initialization function. Args contains the user-supplied
437 * parameters. FIXME: maybe an AVOption-based system would be better?
438 * opaque is data provided by the code requesting creation of the filter,
439 * and is used to pass data to the filter.
441 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
444 * Filter uninitialization function. Should deallocate any memory held
445 * by the filter, release any picture references, etc. This does not need
446 * to deallocate the AVFilterContext->priv memory itself.
448 void (*uninit)(AVFilterContext *ctx);
451 * Queries formats supported by the filter and its pads, and sets the
452 * in_formats for links connected to its output pads, and out_formats
453 * for links connected to its input pads.
455 * @return zero on success, a negative value corresponding to an
456 * AVERROR code otherwise
458 int (*query_formats)(AVFilterContext *);
460 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
461 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
464 * A description for the filter. You should use the
465 * NULL_IF_CONFIG_SMALL() macro to define it.
467 const char *description;
470 /** An instance of a filter */
471 struct AVFilterContext
473 const AVClass *av_class; ///< needed for av_log()
475 AVFilter *filter; ///< the AVFilter of which this is an instance
477 char *name; ///< name of this filter instance
479 unsigned input_count; ///< number of input pads
480 AVFilterPad *input_pads; ///< array of input pads
481 AVFilterLink **inputs; ///< array of pointers to input links
483 unsigned output_count; ///< number of output pads
484 AVFilterPad *output_pads; ///< array of output pads
485 AVFilterLink **outputs; ///< array of pointers to output links
487 void *priv; ///< private data for use by the filter
491 * A link between two filters. This contains pointers to the source and
492 * destination filters between which this link exists, and the indexes of
493 * the pads involved. In addition, this link also contains the parameters
494 * which have been negotiated and agreed upon between the filter, such as
495 * image dimensions, format, etc.
499 AVFilterContext *src; ///< source filter
500 unsigned int srcpad; ///< index of the output pad on the source filter
502 AVFilterContext *dst; ///< dest filter
503 unsigned int dstpad; ///< index of the input pad on the dest filter
505 /** stage of the initialization of the link properties (dimensions, etc) */
507 AVLINK_UNINIT = 0, ///< not started
508 AVLINK_STARTINIT, ///< started, but incomplete
509 AVLINK_INIT ///< complete
512 enum AVMediaType type; ///< filter media type
514 int w; ///< agreed upon image width
515 int h; ///< agreed upon image height
516 int format; ///< agreed upon media format
519 * Lists of formats supported by the input and output filters respectively.
520 * These lists are used for negotiating the format to actually be used,
521 * which will be loaded into the format member, above, when chosen.
523 AVFilterFormats *in_formats;
524 AVFilterFormats *out_formats;
527 * The picture reference currently being sent across the link by the source
528 * filter. This is used internally by the filter system to allow
529 * automatic copying of pictures which do not have sufficient permissions
530 * for the destination. This should not be accessed directly by the
533 AVFilterBufferRef *srcpic;
535 AVFilterBufferRef *cur_pic;
536 AVFilterBufferRef *outpic;
540 * Link two filters together.
541 * @param src the source filter
542 * @param srcpad index of the output pad on the source filter
543 * @param dst the destination filter
544 * @param dstpad index of the input pad on the destination filter
545 * @return zero on success
547 int avfilter_link(AVFilterContext *src, unsigned srcpad,
548 AVFilterContext *dst, unsigned dstpad);
551 * Negotiate the media format, dimensions, etc of all inputs to a filter.
552 * @param filter the filter to negotiate the properties for its inputs
553 * @return zero on successful negotiation
555 int avfilter_config_links(AVFilterContext *filter);
558 * Request a picture buffer with a specific set of permissions.
559 * @param link the output link to the filter from which the picture will
561 * @param perms the required access permissions
562 * @param w the minimum width of the buffer to allocate
563 * @param h the minimum height of the buffer to allocate
564 * @return A reference to the picture. This must be unreferenced with
565 * avfilter_unref_pic when you are finished with it.
567 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
571 * Request an input frame from the filter at the other end of the link.
572 * @param link the input link
573 * @return zero on success
575 int avfilter_request_frame(AVFilterLink *link);
578 * Poll a frame from the filter chain.
579 * @param link the input link
580 * @return the number of immediately available frames, a negative
581 * number in case of error
583 int avfilter_poll_frame(AVFilterLink *link);
586 * Notifie the next filter of the start of a frame.
587 * @param link the output link the frame will be sent over
588 * @param picref A reference to the frame about to be sent. The data for this
589 * frame need only be valid once draw_slice() is called for that
590 * portion. The receiving filter will free this reference when
591 * it no longer needs it.
593 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
596 * Notifie the next filter that the current frame has finished.
597 * @param link the output link the frame was sent over
599 void avfilter_end_frame(AVFilterLink *link);
602 * Send a slice to the next filter.
604 * Slices have to be provided in sequential order, either in
605 * top-bottom or bottom-top order. If slices are provided in
606 * non-sequential order the behavior of the function is undefined.
608 * @param link the output link over which the frame is being sent
609 * @param y offset in pixels from the top of the image for this slice
610 * @param h height of this slice in pixels
611 * @param slice_dir the assumed direction for sending slices,
612 * from the top slice to the bottom slice if the value is 1,
613 * from the bottom slice to the top slice if the value is -1,
614 * for other values the behavior of the function is undefined.
616 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
618 /** Initialize the filter system. Register all builtin filters. */
619 void avfilter_register_all(void);
621 /** Uninitialize the filter system. Unregister all filters. */
622 void avfilter_uninit(void);
625 * Register a filter. This is only needed if you plan to use
626 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
627 * filter can still by instantiated with avfilter_open even if it is not
629 * @param filter the filter to register
630 * @return 0 if the registration was succesfull, a negative value
633 int avfilter_register(AVFilter *filter);
636 * Get a filter definition matching the given name.
637 * @param name the filter name to find
638 * @return the filter definition, if any matching one is registered.
639 * NULL if none found.
641 AVFilter *avfilter_get_by_name(const char *name);
644 * If filter is NULL, returns a pointer to the first registered filter pointer,
645 * if filter is non-NULL, returns the next pointer after filter.
646 * If the returned pointer points to NULL, the last registered filter
647 * was already reached.
649 AVFilter **av_filter_next(AVFilter **filter);
652 * Create a filter instance.
653 * @param filter the filter to create an instance of
654 * @param inst_name Name to give to the new instance. Can be NULL for none.
655 * @return Pointer to the new instance on success. NULL on failure.
657 AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
660 * Initialize a filter.
661 * @param filter the filter to initialize
662 * @param args A string of parameters to use when initializing the filter.
663 * The format and meaning of this string varies by filter.
664 * @param opaque Any extra non-string data needed by the filter. The meaning
665 * of this parameter varies by filter.
666 * @return zero on success
668 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
672 * @param filter the filter to destroy
674 void avfilter_destroy(AVFilterContext *filter);
677 * Insert a filter in the middle of an existing link.
678 * @param link the link into which the filter should be inserted
679 * @param filt the filter to be inserted
680 * @param in the input pad on the filter to connect
681 * @param out the output pad on the filter to connect
682 * @return zero on success
684 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
685 unsigned in, unsigned out);
689 * @param idx Insertion point. Pad is inserted at the end if this point
690 * is beyond the end of the list of pads.
691 * @param count Pointer to the number of pads in the list
692 * @param padidx_off Offset within an AVFilterLink structure to the element
693 * to increment when inserting a new pad causes link
694 * numbering to change
695 * @param pads Pointer to the pointer to the beginning of the list of pads
696 * @param links Pointer to the pointer to the beginning of the list of links
697 * @param newpad The new pad to add. A copy is made when adding.
699 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
700 AVFilterPad **pads, AVFilterLink ***links,
701 AVFilterPad *newpad);
703 /** Insert a new input pad for the filter. */
704 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
707 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
708 &f->input_pads, &f->inputs, p);
711 /** Insert a new output pad for the filter. */
712 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
715 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
716 &f->output_pads, &f->outputs, p);
719 #endif /* AVFILTER_AVFILTER_H */