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 25
29 #define LIBAVFILTER_VERSION_MICRO 1
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 * AVFilterPicRef structure below.
67 typedef struct AVFilterBuffer
69 uint8_t *data[4]; ///< buffer data for each plane
70 int linesize[4]; ///< number of bytes per line
71 enum PixelFormat format; ///< colorspace
73 unsigned refcount; ///< number of references to this buffer
75 /** private data to be used by a custom free function */
78 * A pointer to the function to deallocate this buffer if the default
79 * function is not sufficient. This could, for example, add the memory
80 * back into a memory pool to be reused later without the overhead of
81 * reallocating it from scratch.
83 void (*free)(struct AVFilterBuffer *buf);
86 #define AV_PERM_READ 0x01 ///< can read from the buffer
87 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
88 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
89 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
90 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
93 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
94 * a picture to, for example, crop image without any memcpy, the picture origin
95 * and dimensions are per-reference properties. Linesize is also useful for
96 * image flipping, frame to field filters, etc, and so is also per-reference.
98 * TODO: add anything necessary for frame reordering
100 typedef struct AVFilterPicRef
102 AVFilterBuffer *pic; ///< the picture that this is a reference to
103 uint8_t *data[4]; ///< picture data for each plane
104 int linesize[4]; ///< number of bytes per line
105 int w; ///< image width
106 int h; ///< image height
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(AVFilterPicRef *dst, AVFilterPicRef *src)
127 dst->pixel_aspect = src->pixel_aspect;
128 dst->interlaced = src->interlaced;
129 dst->top_field_first = src->top_field_first;
133 * Add a new reference to a picture.
134 * @param ref an existing reference to the picture
135 * @param pmask a bitmask containing the allowable permissions in the new
137 * @return a new reference to the picture with the same properties as the
138 * old, excluding any permissions denied by pmask
140 AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
143 * Remove a reference to a picture. If this is the last reference to the
144 * picture, the picture itself is also automatically freed.
145 * @param ref reference to the picture
147 void avfilter_unref_pic(AVFilterPicRef *ref);
150 * A list of supported formats for one end of a filter link. This is used
151 * during the format negotiation process to try to pick the best format to
152 * use to minimize the number of necessary conversions. Each filter gives a
153 * list of the formats supported by each input and output pad. The list
154 * given for each pad need not be distinct - they may be references to the
155 * same list of formats, as is often the case when a filter supports multiple
156 * formats, but will always output the same format as it is given in input.
158 * In this way, a list of possible input formats and a list of possible
159 * output formats are associated with each link. When a set of formats is
160 * negotiated over a link, the input and output lists are merged to form a
161 * new list containing only the common elements of each list. In the case
162 * that there were no common elements, a format conversion is necessary.
163 * Otherwise, the lists are merged, and all other links which reference
164 * either of the format lists involved in the merge are also affected.
166 * For example, consider the filter chain:
167 * filter (a) --> (b) filter (b) --> (c) filter
169 * where the letters in parenthesis indicate a list of formats supported on
170 * the input or output of the link. Suppose the lists are as follows:
175 * First, the first link's lists are merged, yielding:
176 * filter (a) --> (a) filter (a) --> (c) filter
178 * Notice that format list (b) now refers to the same list as filter list (a).
179 * Next, the lists for the second link are merged, yielding:
180 * filter (a) --> (a) filter (a) --> (a) filter
184 * Unfortunately, when the format lists at the two ends of a link are merged,
185 * we must ensure that all links which reference either pre-merge format list
186 * get updated as well. Therefore, we have the format list structure store a
187 * pointer to each of the pointers to itself.
189 typedef struct AVFilterFormats AVFilterFormats;
190 struct AVFilterFormats
192 unsigned format_count; ///< number of formats
193 enum PixelFormat *formats; ///< list of pixel formats
195 unsigned refcount; ///< number of references to this list
196 AVFilterFormats ***refs; ///< references to this list
200 * Create a list of supported formats. This is intended for use in
201 * AVFilter->query_formats().
202 * @param pix_fmts list of pixel formats, terminated by PIX_FMT_NONE
203 * @return the format list, with no existing references
205 AVFilterFormats *avfilter_make_format_list(const enum PixelFormat *pix_fmts);
208 * Add pix_fmt to the list of pixel formats contained in *avff.
209 * If *avff is NULL the function allocates the filter formats struct
210 * and puts its pointer in *avff.
212 * @return a non negative value in case of success, or a negative
213 * value corresponding to an AVERROR code in case of error
215 int avfilter_add_colorspace(AVFilterFormats **avff, enum PixelFormat pix_fmt);
218 * Return a list of all colorspaces supported by FFmpeg.
220 AVFilterFormats *avfilter_all_colorspaces(void);
223 * Return a format list which contains the intersection of the formats of
224 * a and b. Also, all the references of a, all the references of b, and
225 * a and b themselves will be deallocated.
227 * If a and b do not share any common formats, neither is modified, and NULL
230 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
233 * Add *ref as a new reference to formats.
234 * That is the pointers will point like in the ascii art below:
236 * |formats |<--------.
237 * | ____ | ____|___________________
239 * | |* * | | | | | | AVFilterLink
240 * | |* *--------->|*ref|
241 * | |____| | | |____|
242 * |________| |________________________
244 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
247 * If *ref is non-NULL, remove *ref as a reference to the format list
248 * it currently points to, deallocates that list if this was the last
249 * reference, and sets *ref to NULL.
252 * ________ ________ NULL
253 * |formats |<--------. |formats | ^
254 * | ____ | ____|________________ | ____ | ____|________________
255 * | |refs| | | __|_ | |refs| | | __|_
256 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
257 * | |* *--------->|*ref| | |* | | | |*ref|
258 * | |____| | | |____| | |____| | | |____|
259 * |________| |_____________________ |________| |_____________________
261 void avfilter_formats_unref(AVFilterFormats **ref);
267 * |formats |<---------. |formats |<---------.
268 * | ____ | ___|___ | ____ | ___|___
269 * | |refs| | | | | | |refs| | | | | NULL
270 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
271 * | |* * | | |_______| | |* * | | |_______| ___|___
272 * | |____| | | |____| | | | |
273 * |________| |________| |*oldref|
276 void avfilter_formats_changeref(AVFilterFormats **oldref,
277 AVFilterFormats **newref);
280 * A filter pad used for either input or output.
285 * Pad name. The name is unique among inputs and among outputs, but an
286 * input may have the same name as an output. This may be NULL if this
287 * pad has no need to ever be referenced by name.
292 * AVFilterPad type. Only video supported now, hopefully someone will
293 * add audio in the future.
295 enum AVMediaType type;
298 * Minimum required permissions on incoming buffers. Any buffer with
299 * insufficient permissions will be automatically copied by the filter
300 * system to a new buffer which provides the needed access permissions.
307 * Permissions which are not accepted on incoming buffers. Any buffer
308 * which has any of these permissions set will be automatically copied
309 * by the filter system to a new buffer which does not have those
310 * permissions. This can be used to easily disallow buffers with
318 * Callback called before passing the first slice of a new frame. If
319 * NULL, the filter layer will default to storing a reference to the
320 * picture inside the link structure.
322 * Input video pads only.
324 void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
327 * Callback function to get a buffer. If NULL, the filter system will
328 * use avfilter_default_get_video_buffer().
330 * Input video pads only.
332 AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
335 * Callback called after the slices of a frame are completely sent. If
336 * NULL, the filter layer will default to releasing the reference stored
337 * in the link structure during start_frame().
339 * Input video pads only.
341 void (*end_frame)(AVFilterLink *link);
344 * Slice drawing callback. This is where a filter receives video data
345 * and should do its processing.
347 * Input video pads only.
349 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
352 * Frame poll callback. This returns the number of immediately available
353 * frames. It should return a positive value if the next request_frame()
354 * is guaranteed to return one frame (with no delay).
356 * Defaults to just calling the source poll_frame() method.
358 * Output video pads only.
360 int (*poll_frame)(AVFilterLink *link);
363 * Frame request callback. A call to this should result in at least one
364 * frame being output over the given link. This should return zero on
365 * success, and another value on error.
367 * Output video pads only.
369 int (*request_frame)(AVFilterLink *link);
372 * Link configuration callback.
374 * For output pads, this should set the link properties such as
375 * width/height. This should NOT set the format property - that is
376 * negotiated between filters by the filter system using the
377 * query_formats() callback before this function is called.
379 * For input pads, this should check the properties of the link, and update
380 * the filter's internal state as necessary.
382 * For both input and output filters, this should return zero on success,
383 * and another value on error.
385 int (*config_props)(AVFilterLink *link);
388 /** default handler for start_frame() for video inputs */
389 void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
390 /** default handler for draw_slice() for video inputs */
391 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
392 /** default handler for end_frame() for video inputs */
393 void avfilter_default_end_frame(AVFilterLink *link);
394 /** default handler for config_props() for video outputs */
395 int avfilter_default_config_output_link(AVFilterLink *link);
396 /** default handler for config_props() for video inputs */
397 int avfilter_default_config_input_link (AVFilterLink *link);
398 /** default handler for get_video_buffer() for video inputs */
399 AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
400 int perms, int w, int h);
402 * A helper for query_formats() which sets all links to the same list of
403 * formats. If there are no links hooked to this filter, the list of formats is
406 void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
407 /** Default handler for query_formats() */
408 int avfilter_default_query_formats(AVFilterContext *ctx);
410 /** start_frame() handler for filters which simply pass video along */
411 void avfilter_null_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
413 /** draw_slice() handler for filters which simply pass video along */
414 void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
416 /** end_frame() handler for filters which simply pass video along */
417 void avfilter_null_end_frame(AVFilterLink *link);
419 /** get_video_buffer() handler for filters which simply pass video along */
420 AVFilterPicRef *avfilter_null_get_video_buffer(AVFilterLink *link,
421 int perms, int w, int h);
424 * Filter definition. This defines the pads a filter contains, and all the
425 * callback functions used to interact with the filter.
427 typedef struct AVFilter
429 const char *name; ///< filter name
431 int priv_size; ///< size of private data to allocate for the filter
434 * Filter initialization function. Args contains the user-supplied
435 * parameters. FIXME: maybe an AVOption-based system would be better?
436 * opaque is data provided by the code requesting creation of the filter,
437 * and is used to pass data to the filter.
439 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
442 * Filter uninitialization function. Should deallocate any memory held
443 * by the filter, release any picture references, etc. This does not need
444 * to deallocate the AVFilterContext->priv memory itself.
446 void (*uninit)(AVFilterContext *ctx);
449 * Queries formats supported by the filter and its pads, and sets the
450 * in_formats for links connected to its output pads, and out_formats
451 * for links connected to its input pads.
453 * @return zero on success, a negative value corresponding to an
454 * AVERROR code otherwise
456 int (*query_formats)(AVFilterContext *);
458 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
459 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
462 * A description for the filter. You should use the
463 * NULL_IF_CONFIG_SMALL() macro to define it.
465 const char *description;
468 /** An instance of a filter */
469 struct AVFilterContext
471 const AVClass *av_class; ///< needed for av_log()
473 AVFilter *filter; ///< the AVFilter of which this is an instance
475 char *name; ///< name of this filter instance
477 unsigned input_count; ///< number of input pads
478 AVFilterPad *input_pads; ///< array of input pads
479 AVFilterLink **inputs; ///< array of pointers to input links
481 unsigned output_count; ///< number of output pads
482 AVFilterPad *output_pads; ///< array of output pads
483 AVFilterLink **outputs; ///< array of pointers to output links
485 void *priv; ///< private data for use by the filter
489 * A link between two filters. This contains pointers to the source and
490 * destination filters between which this link exists, and the indexes of
491 * the pads involved. In addition, this link also contains the parameters
492 * which have been negotiated and agreed upon between the filter, such as
493 * image dimensions, format, etc.
497 AVFilterContext *src; ///< source filter
498 unsigned int srcpad; ///< index of the output pad on the source filter
500 AVFilterContext *dst; ///< dest filter
501 unsigned int dstpad; ///< index of the input pad on the dest filter
503 /** stage of the initialization of the link properties (dimensions, etc) */
505 AVLINK_UNINIT = 0, ///< not started
506 AVLINK_STARTINIT, ///< started, but incomplete
507 AVLINK_INIT ///< complete
510 int w; ///< agreed upon image width
511 int h; ///< agreed upon image height
512 enum PixelFormat format; ///< agreed upon image colorspace
515 * Lists of formats supported by the input and output filters respectively.
516 * These lists are used for negotiating the format to actually be used,
517 * which will be loaded into the format member, above, when chosen.
519 AVFilterFormats *in_formats;
520 AVFilterFormats *out_formats;
523 * The picture reference currently being sent across the link by the source
524 * filter. This is used internally by the filter system to allow
525 * automatic copying of pictures which do not have sufficient permissions
526 * for the destination. This should not be accessed directly by the
529 AVFilterPicRef *srcpic;
531 AVFilterPicRef *cur_pic;
532 AVFilterPicRef *outpic;
536 * Link two filters together.
537 * @param src the source filter
538 * @param srcpad index of the output pad on the source filter
539 * @param dst the destination filter
540 * @param dstpad index of the input pad on the destination filter
541 * @return zero on success
543 int avfilter_link(AVFilterContext *src, unsigned srcpad,
544 AVFilterContext *dst, unsigned dstpad);
547 * Negotiate the colorspace, dimensions, etc of all inputs to a filter.
548 * @param filter the filter to negotiate the properties for its inputs
549 * @return zero on successful negotiation
551 int avfilter_config_links(AVFilterContext *filter);
554 * Request a picture buffer with a specific set of permissions.
555 * @param link the output link to the filter from which the picture will
557 * @param perms the required access permissions
558 * @param w the minimum width of the buffer to allocate
559 * @param h the minimum height of the buffer to allocate
560 * @return A reference to the picture. This must be unreferenced with
561 * avfilter_unref_pic when you are finished with it.
563 AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
567 * Request an input frame from the filter at the other end of the link.
568 * @param link the input link
569 * @return zero on success
571 int avfilter_request_frame(AVFilterLink *link);
574 * Poll a frame from the filter chain.
575 * @param link the input link
576 * @return the number of immediately available frames, a negative
577 * number in case of error
579 int avfilter_poll_frame(AVFilterLink *link);
582 * Notifie the next filter of the start of a frame.
583 * @param link the output link the frame will be sent over
584 * @param picref A reference to the frame about to be sent. The data for this
585 * frame need only be valid once draw_slice() is called for that
586 * portion. The receiving filter will free this reference when
587 * it no longer needs it.
589 void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
592 * Notifie the next filter that the current frame has finished.
593 * @param link the output link the frame was sent over
595 void avfilter_end_frame(AVFilterLink *link);
598 * Send a slice to the next filter.
600 * Slices have to be provided in sequential order, either in
601 * top-bottom or bottom-top order. If slices are provided in
602 * non-sequential order the behavior of the function is undefined.
604 * @param link the output link over which the frame is being sent
605 * @param y offset in pixels from the top of the image for this slice
606 * @param h height of this slice in pixels
607 * @param slice_dir the assumed direction for sending slices,
608 * from the top slice to the bottom slice if the value is 1,
609 * from the bottom slice to the top slice if the value is -1,
610 * for other values the behavior of the function is undefined.
612 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
614 /** Initialize the filter system. Register all builtin filters. */
615 void avfilter_register_all(void);
617 /** Uninitialize the filter system. Unregister all filters. */
618 void avfilter_uninit(void);
621 * Register a filter. This is only needed if you plan to use
622 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
623 * filter can still by instantiated with avfilter_open even if it is not
625 * @param filter the filter to register
626 * @return 0 if the registration was succesfull, a negative value
629 int avfilter_register(AVFilter *filter);
632 * Get a filter definition matching the given name.
633 * @param name the filter name to find
634 * @return the filter definition, if any matching one is registered.
635 * NULL if none found.
637 AVFilter *avfilter_get_by_name(const char *name);
640 * If filter is NULL, returns a pointer to the first registered filter pointer,
641 * if filter is non-NULL, returns the next pointer after filter.
642 * If the returned pointer points to NULL, the last registered filter
643 * was already reached.
645 AVFilter **av_filter_next(AVFilter **filter);
648 * Create a filter instance.
649 * @param filter the filter to create an instance of
650 * @param inst_name Name to give to the new instance. Can be NULL for none.
651 * @return Pointer to the new instance on success. NULL on failure.
653 AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
656 * Initialize a filter.
657 * @param filter the filter to initialize
658 * @param args A string of parameters to use when initializing the filter.
659 * The format and meaning of this string varies by filter.
660 * @param opaque Any extra non-string data needed by the filter. The meaning
661 * of this parameter varies by filter.
662 * @return zero on success
664 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
668 * @param filter the filter to destroy
670 void avfilter_destroy(AVFilterContext *filter);
673 * Insert a filter in the middle of an existing link.
674 * @param link the link into which the filter should be inserted
675 * @param filt the filter to be inserted
676 * @param in the input pad on the filter to connect
677 * @param out the output pad on the filter to connect
678 * @return zero on success
680 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
681 unsigned in, unsigned out);
685 * @param idx Insertion point. Pad is inserted at the end if this point
686 * is beyond the end of the list of pads.
687 * @param count Pointer to the number of pads in the list
688 * @param padidx_off Offset within an AVFilterLink structure to the element
689 * to increment when inserting a new pad causes link
690 * numbering to change
691 * @param pads Pointer to the pointer to the beginning of the list of pads
692 * @param links Pointer to the pointer to the beginning of the list of links
693 * @param newpad The new pad to add. A copy is made when adding.
695 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
696 AVFilterPad **pads, AVFilterLink ***links,
697 AVFilterPad *newpad);
699 /** Insert a new input pad for the filter. */
700 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
703 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
704 &f->input_pads, &f->inputs, p);
707 /** Insert a new output pad for the filter. */
708 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
711 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
712 &f->output_pads, &f->outputs, p);
715 #endif /* AVFILTER_AVFILTER_H */