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 #define LIBAVFILTER_VERSION_MAJOR 1
26 #define LIBAVFILTER_VERSION_MINOR 6
27 #define LIBAVFILTER_VERSION_MICRO 0
29 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
30 LIBAVFILTER_VERSION_MINOR, \
31 LIBAVFILTER_VERSION_MICRO)
32 #define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
33 LIBAVFILTER_VERSION_MINOR, \
34 LIBAVFILTER_VERSION_MICRO)
35 #define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
38 #include "libavcodec/avcodec.h"
41 * Returns the LIBAVFILTER_VERSION_INT constant.
43 unsigned avfilter_version(void);
45 typedef struct AVFilterContext AVFilterContext
;
46 typedef struct AVFilterLink AVFilterLink
;
47 typedef struct AVFilterPad AVFilterPad
;
49 /* TODO: look for other flags which may be useful in this structure (interlace
53 * A reference-counted picture data type used by the filter system. Filters
54 * should not store pointers to this structure directly, but instead use the
55 * AVFilterPicRef structure below.
57 typedef struct AVFilterPic
59 uint8_t *data
[4]; ///< picture data for each plane
60 int linesize
[4]; ///< number of bytes per line
61 enum PixelFormat format
; ///< colorspace
63 unsigned refcount
; ///< number of references to this image
65 /** private data to be used by a custom free function */
68 * A pointer to the function to deallocate this image if the default
69 * function is not sufficient. This could, for example, add the memory
70 * back into a memory pool to be reused later without the overhead of
71 * reallocating it from scratch.
73 void (*free
)(struct AVFilterPic
*pic
);
75 int w
, h
; ///< width and height of the allocated buffer
79 * A reference to an AVFilterPic. Since filters can manipulate the origin of
80 * a picture to, for example, crop image without any memcpy, the picture origin
81 * and dimensions are per-reference properties. Linesize is also useful for
82 * image flipping, frame to field filters, etc, and so is also per-reference.
84 * TODO: add anything necessary for frame reordering
86 typedef struct AVFilterPicRef
88 AVFilterPic
*pic
; ///< the picture that this is a reference to
89 uint8_t *data
[4]; ///< picture data for each plane
90 int linesize
[4]; ///< number of bytes per line
91 int w
; ///< image width
92 int h
; ///< image height
94 int64_t pts
; ///< presentation timestamp in units of 1/AV_TIME_BASE
96 AVRational pixel_aspect
; ///< pixel aspect ratio
98 int perms
; ///< permissions
99 #define AV_PERM_READ 0x01 ///< can read from the buffer
100 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
101 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
102 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
103 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
107 * Adds a new reference to a picture.
108 * @param ref an existing reference to the picture
109 * @param pmask a bitmask containing the allowable permissions in the new
111 * @return a new reference to the picture with the same properties as the
112 * old, excluding any permissions denied by pmask
114 AVFilterPicRef
*avfilter_ref_pic(AVFilterPicRef
*ref
, int pmask
);
117 * Removes a reference to a picture. If this is the last reference to the
118 * picture, the picture itself is also automatically freed.
119 * @param ref reference to the picture
121 void avfilter_unref_pic(AVFilterPicRef
*ref
);
124 * A list of supported formats for one end of a filter link. This is used
125 * during the format negotiation process to try to pick the best format to
126 * use to minimize the number of necessary conversions. Each filter gives a
127 * list of the formats supported by each input and output pad. The list
128 * given for each pad need not be distinct - they may be references to the
129 * same list of formats, as is often the case when a filter supports multiple
130 * formats, but will always output the same format as it is given in input.
132 * In this way, a list of possible input formats and a list of possible
133 * output formats are associated with each link. When a set of formats is
134 * negotiated over a link, the input and output lists are merged to form a
135 * new list containing only the common elements of each list. In the case
136 * that there were no common elements, a format conversion is necessary.
137 * Otherwise, the lists are merged, and all other links which reference
138 * either of the format lists involved in the merge are also affected.
140 * For example, consider the filter chain:
141 * filter (a) --> (b) filter (b) --> (c) filter
143 * where the letters in parenthesis indicate a list of formats supported on
144 * the input or output of the link. Suppose the lists are as follows:
149 * First, the first link's lists are merged, yielding:
150 * filter (a) --> (a) filter (a) --> (c) filter
152 * Notice that format list (b) now refers to the same list as filter list (a).
153 * Next, the lists for the second link are merged, yielding:
154 * filter (a) --> (a) filter (a) --> (a) filter
158 * Unfortunately, when the format lists at the two ends of a link are merged,
159 * we must ensure that all links which reference either pre-merge format list
160 * get updated as well. Therefore, we have the format list structure store a
161 * pointer to each of the pointers to itself.
163 typedef struct AVFilterFormats AVFilterFormats
;
164 struct AVFilterFormats
166 unsigned format_count
; ///< number of formats
167 enum PixelFormat
*formats
; ///< list of pixel formats
169 unsigned refcount
; ///< number of references to this list
170 AVFilterFormats
***refs
; ///< references to this list
174 * Creates a list of supported formats. This is intended for use in
175 * AVFilter->query_formats().
176 * @param pix_fmt list of pixel formats, terminated by PIX_FMT_NONE
177 * @return the format list, with no existing references
179 AVFilterFormats
*avfilter_make_format_list(const enum PixelFormat
*pix_fmts
);
182 * Returns a list of all colorspaces supported by FFmpeg.
184 AVFilterFormats
*avfilter_all_colorspaces(void);
187 * Returns a format list which contains the intersection of the formats of
188 * a and b. Also, all the references of a, all the references of b, and
189 * a and b themselves will be deallocated.
191 * If a and b do not share any common formats, neither is modified, and NULL
194 AVFilterFormats
*avfilter_merge_formats(AVFilterFormats
*a
, AVFilterFormats
*b
);
197 * Adds *ref as a new reference to formats.
198 * That is the pointers will point like in the ascii art below:
200 * |formats |<--------.
201 * | ____ | ____|___________________
203 * | |* * | | | | | | AVFilterLink
204 * | |* *--------->|*ref|
205 * | |____| | | |____|
206 * |________| |________________________
208 void avfilter_formats_ref(AVFilterFormats
*formats
, AVFilterFormats
**ref
);
211 * Removes *ref as a reference to the format list it currently points to,
212 * deallocates that list if this was the last reference, and sets *ref to NULL.
215 * ________ ________ NULL
216 * |formats |<--------. |formats | ^
217 * | ____ | ____|________________ | ____ | ____|________________
218 * | |refs| | | __|_ | |refs| | | __|_
219 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
220 * | |* *--------->|*ref| | |* | | | |*ref|
221 * | |____| | | |____| | |____| | | |____|
222 * |________| |_____________________ |________| |_____________________
224 void avfilter_formats_unref(AVFilterFormats
**ref
);
230 * |formats |<---------. |formats |<---------.
231 * | ____ | ___|___ | ____ | ___|___
232 * | |refs| | | | | | |refs| | | | | NULL
233 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
234 * | |* * | | |_______| | |* * | | |_______| ___|___
235 * | |____| | | |____| | | | |
236 * |________| |________| |*oldref|
239 void avfilter_formats_changeref(AVFilterFormats
**oldref
,
240 AVFilterFormats
**newref
);
243 * A filter pad used for either input or output.
248 * Pad name. The name is unique among inputs and among outputs, but an
249 * input may have the same name as an output. This may be NULL if this
250 * pad has no need to ever be referenced by name.
255 * AVFilterPad type. Only video supported now, hopefully someone will
256 * add audio in the future.
261 * Minimum required permissions on incoming buffers. Any buffer with
262 * insufficient permissions will be automatically copied by the filter
263 * system to a new buffer which provides the needed access permissions.
270 * Permissions which are not accepted on incoming buffers. Any buffer
271 * which has any of these permissions set will be automatically copied
272 * by the filter system to a new buffer which does not have those
273 * permissions. This can be used to easily disallow buffers with
281 * Callback called before passing the first slice of a new frame. If
282 * NULL, the filter layer will default to storing a reference to the
283 * picture inside the link structure.
285 * Input video pads only.
287 void (*start_frame
)(AVFilterLink
*link
, AVFilterPicRef
*picref
);
290 * Callback function to get a buffer. If NULL, the filter system will
291 * handle buffer requests.
293 * Input video pads only.
295 AVFilterPicRef
*(*get_video_buffer
)(AVFilterLink
*link
, int perms
, int w
, int h
);
298 * Callback called after the slices of a frame are completely sent. If
299 * NULL, the filter layer will default to releasing the reference stored
300 * in the link structure during start_frame().
302 * Input video pads only.
304 void (*end_frame
)(AVFilterLink
*link
);
307 * Slice drawing callback. This is where a filter receives video data
308 * and should do its processing.
310 * Input video pads only.
312 void (*draw_slice
)(AVFilterLink
*link
, int y
, int height
);
315 * Frame poll callback. This returns the number of immediately available
316 * frames. It should return a positive value if the next request_frame()
317 * is guaranteed to return one frame (with no delay).
319 * Defaults to just calling the source poll_frame() method.
321 * Output video pads only.
323 int (*poll_frame
)(AVFilterLink
*link
);
326 * Frame request callback. A call to this should result in at least one
327 * frame being output over the given link. This should return zero on
328 * success, and another value on error.
330 * Output video pads only.
332 int (*request_frame
)(AVFilterLink
*link
);
335 * Link configuration callback.
337 * For output pads, this should set the link properties such as
338 * width/height. This should NOT set the format property - that is
339 * negotiated between filters by the filter system using the
340 * query_formats() callback before this function is called.
342 * For input pads, this should check the properties of the link, and update
343 * the filter's internal state as necessary.
345 * For both input and output filters, this should return zero on success,
346 * and another value on error.
348 int (*config_props
)(AVFilterLink
*link
);
351 /** default handler for start_frame() for video inputs */
352 void avfilter_default_start_frame(AVFilterLink
*link
, AVFilterPicRef
*picref
);
353 /** default handler for draw_slice() for video inputs */
354 void avfilter_default_draw_slice(AVFilterLink
*link
, int y
, int h
);
355 /** default handler for end_frame() for video inputs */
356 void avfilter_default_end_frame(AVFilterLink
*link
);
357 /** default handler for config_props() for video outputs */
358 int avfilter_default_config_output_link(AVFilterLink
*link
);
359 /** default handler for config_props() for video inputs */
360 int avfilter_default_config_input_link (AVFilterLink
*link
);
361 /** default handler for get_video_buffer() for video inputs */
362 AVFilterPicRef
*avfilter_default_get_video_buffer(AVFilterLink
*link
,
363 int perms
, int w
, int h
);
365 * A helper for query_formats() which sets all links to the same list of
366 * formats. If there are no links hooked to this filter, the list of formats is
369 void avfilter_set_common_formats(AVFilterContext
*ctx
, AVFilterFormats
*formats
);
370 /** Default handler for query_formats() */
371 int avfilter_default_query_formats(AVFilterContext
*ctx
);
374 * Filter definition. This defines the pads a filter contains, and all the
375 * callback functions used to interact with the filter.
377 typedef struct AVFilter
379 const char *name
; ///< filter name
381 int priv_size
; ///< size of private data to allocate for the filter
384 * Filter initialization function. Args contains the user-supplied
385 * parameters. FIXME: maybe an AVOption-based system would be better?
386 * opaque is data provided by the code requesting creation of the filter,
387 * and is used to pass data to the filter.
389 int (*init
)(AVFilterContext
*ctx
, const char *args
, void *opaque
);
392 * Filter uninitialization function. Should deallocate any memory held
393 * by the filter, release any picture references, etc. This does not need
394 * to deallocate the AVFilterContext->priv memory itself.
396 void (*uninit
)(AVFilterContext
*ctx
);
399 * Query formats supported by the filter and its pads. Should set the
400 * in_formats for links connected to its output pads, and out_formats
401 * for links connected to its input pads.
403 * Should return zero on success.
405 int (*query_formats
)(AVFilterContext
*);
407 const AVFilterPad
*inputs
; ///< NULL terminated list of inputs. NULL if none
408 const AVFilterPad
*outputs
; ///< NULL terminated list of outputs. NULL if none
411 * A description for the filter. You should use the
412 * NULL_IF_CONFIG_SMALL() macro to define it.
414 const char *description
;
417 * The next registered filter, NULL if this is the last one.
419 struct AVFilter
*next
;
422 /** An instance of a filter */
423 struct AVFilterContext
425 const AVClass
*av_class
; ///< needed for av_log()
427 AVFilter
*filter
; ///< the AVFilter of which this is an instance
429 char *name
; ///< name of this filter instance
431 unsigned input_count
; ///< number of input pads
432 AVFilterPad
*input_pads
; ///< array of input pads
433 AVFilterLink
**inputs
; ///< array of pointers to input links
435 unsigned output_count
; ///< number of output pads
436 AVFilterPad
*output_pads
; ///< array of output pads
437 AVFilterLink
**outputs
; ///< array of pointers to output links
439 void *priv
; ///< private data for use by the filter
443 * A link between two filters. This contains pointers to the source and
444 * destination filters between which this link exists, and the indexes of
445 * the pads involved. In addition, this link also contains the parameters
446 * which have been negotiated and agreed upon between the filter, such as
447 * image dimensions, format, etc.
451 AVFilterContext
*src
; ///< source filter
452 unsigned int srcpad
; ///< index of the output pad on the source filter
454 AVFilterContext
*dst
; ///< dest filter
455 unsigned int dstpad
; ///< index of the input pad on the dest filter
457 /** stage of the initialization of the link properties (dimensions, etc) */
459 AVLINK_UNINIT
= 0, ///< not started
460 AVLINK_STARTINIT
, ///< started, but incomplete
461 AVLINK_INIT
///< complete
464 int w
; ///< agreed upon image width
465 int h
; ///< agreed upon image height
466 enum PixelFormat format
; ///< agreed upon image colorspace
469 * Lists of formats supported by the input and output filters respectively.
470 * These lists are used for negotiating the format to actually be used,
471 * which will be loaded into the format member, above, when chosen.
473 AVFilterFormats
*in_formats
;
474 AVFilterFormats
*out_formats
;
477 * The picture reference currently being sent across the link by the source
478 * filter. This is used internally by the filter system to allow
479 * automatic copying of pictures which do not have sufficient permissions
480 * for the destination. This should not be accessed directly by the
483 AVFilterPicRef
*srcpic
;
485 AVFilterPicRef
*cur_pic
;
486 AVFilterPicRef
*outpic
;
490 * Links two filters together.
491 * @param src the source filter
492 * @param srcpad index of the output pad on the source filter
493 * @param dst the destination filter
494 * @param dstpad index of the input pad on the destination filter
495 * @return zero on success
497 int avfilter_link(AVFilterContext
*src
, unsigned srcpad
,
498 AVFilterContext
*dst
, unsigned dstpad
);
501 * Negotiates the colorspace, dimensions, etc of all inputs to a filter.
502 * @param filter the filter to negotiate the properties for its inputs
503 * @return zero on successful negotiation
505 int avfilter_config_links(AVFilterContext
*filter
);
508 * Requests a picture buffer with a specific set of permissions.
509 * @param link the output link to the filter from which the picture will
511 * @param perms the required access permissions
512 * @param w the minimum width of the buffer to allocate
513 * @param h the minimum height of the buffer to allocate
514 * @return A reference to the picture. This must be unreferenced with
515 * avfilter_unref_pic when you are finished with it.
517 AVFilterPicRef
*avfilter_get_video_buffer(AVFilterLink
*link
, int perms
,
521 * Requests an input frame from the filter at the other end of the link.
522 * @param link the input link
523 * @return zero on success
525 int avfilter_request_frame(AVFilterLink
*link
);
528 * Polls a frame from the filter chain.
529 * @param link the input link
530 * @return the number of immediately available frames, a negative
531 * number in case of error
533 int avfilter_poll_frame(AVFilterLink
*link
);
536 * Notifies the next filter of the start of a frame.
537 * @param link the output link the frame will be sent over
538 * @param picref A reference to the frame about to be sent. The data for this
539 * frame need only be valid once draw_slice() is called for that
540 * portion. The receiving filter will free this reference when
541 * it no longer needs it.
543 void avfilter_start_frame(AVFilterLink
*link
, AVFilterPicRef
*picref
);
546 * Notifies the next filter that the current frame has finished.
547 * @param link the output link the frame was sent over
549 void avfilter_end_frame(AVFilterLink
*link
);
552 * Sends a slice to the next filter.
553 * @param link the output link over which the frame is being sent
554 * @param y offset in pixels from the top of the image for this slice
555 * @param h height of this slice in pixels
557 void avfilter_draw_slice(AVFilterLink
*link
, int y
, int h
);
559 /** Initializes the filter system. Registers all builtin filters. */
560 void avfilter_register_all(void);
562 /** Uninitializes the filter system. Unregisters all filters. */
563 void avfilter_uninit(void);
566 * Registers a filter. This is only needed if you plan to use
567 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
568 * filter can still by instantiated with avfilter_open even if it is not
570 * @param filter the filter to register
572 void avfilter_register(AVFilter
*filter
);
575 * Gets a filter definition matching the given name.
576 * @param name the filter name to find
577 * @return the filter definition, if any matching one is registered.
578 * NULL if none found.
580 AVFilter
*avfilter_get_by_name(const char *name
);
583 * Creates a filter instance.
584 * @param filter the filter to create an instance of
585 * @param inst_name Name to give to the new instance. Can be NULL for none.
586 * @return Pointer to the new instance on success. NULL on failure.
588 AVFilterContext
*avfilter_open(AVFilter
*filter
, const char *inst_name
);
591 * Initializes a filter.
592 * @param filter the filter to initialize
593 * @param args A string of parameters to use when initializing the filter.
594 * The format and meaning of this string varies by filter.
595 * @param opaque Any extra non-string data needed by the filter. The meaning
596 * of this parameter varies by filter.
597 * @return zero on success
599 int avfilter_init_filter(AVFilterContext
*filter
, const char *args
, void *opaque
);
603 * @param filter the filter to destroy
605 void avfilter_destroy(AVFilterContext
*filter
);
608 * Inserts a filter in the middle of an existing link.
609 * @param link the link into which the filter should be inserted
610 * @param filt the filter to be inserted
611 * @param in the input pad on the filter to connect
612 * @param out the output pad on the filter to connect
613 * @return zero on success
615 int avfilter_insert_filter(AVFilterLink
*link
, AVFilterContext
*filt
,
616 unsigned in
, unsigned out
);
620 * @param idx Insertion point. Pad is inserted at the end if this point
621 * is beyond the end of the list of pads.
622 * @param count Pointer to the number of pads in the list
623 * @param padidx_off Offset within an AVFilterLink structure to the element
624 * to increment when inserting a new pad causes link
625 * numbering to change
626 * @param pads Pointer to the pointer to the beginning of the list of pads
627 * @param links Pointer to the pointer to the beginning of the list of links
628 * @param newpad The new pad to add. A copy is made when adding.
630 void avfilter_insert_pad(unsigned idx
, unsigned *count
, size_t padidx_off
,
631 AVFilterPad
**pads
, AVFilterLink
***links
,
632 AVFilterPad
*newpad
);
634 /** Inserts a new input pad for the filter. */
635 static inline void avfilter_insert_inpad(AVFilterContext
*f
, unsigned index
,
638 avfilter_insert_pad(index
, &f
->input_count
, offsetof(AVFilterLink
, dstpad
),
639 &f
->input_pads
, &f
->inputs
, p
);
642 /** Inserts a new output pad for the filter. */
643 static inline void avfilter_insert_outpad(AVFilterContext
*f
, unsigned index
,
646 avfilter_insert_pad(index
, &f
->output_count
, offsetof(AVFilterLink
, srcpad
),
647 &f
->output_pads
, &f
->outputs
, p
);
650 #endif /* AVFILTER_AVFILTER_H */