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 FFMPEG_AVFILTER_H
23 #define FFMPEG_AVFILTER_H
25 #define LIBAVFILTER_VERSION_MAJOR 0
26 #define LIBAVFILTER_VERSION_MINOR 1
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);
77 * A reference to an AVFilterPic. Since filters can manipulate the origin of
78 * a picture to, for example, crop image without any memcpy, the picture origin
79 * and dimensions are per-reference properties. Linesize is also useful for
80 * image flipping, frame to field filters, etc, and so is also per-reference.
82 * TODO: add anything necessary for frame reordering
84 typedef struct AVFilterPicRef
86 AVFilterPic *pic; ///< the picture that this is a reference to
87 uint8_t *data[4]; ///< picture data for each plane
88 int linesize[4]; ///< number of bytes per line
89 int w; ///< image width
90 int h; ///< image height
92 int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
94 AVRational pixel_aspect; ///< pixel aspect ratio
96 int perms; ///< permissions
97 #define AV_PERM_READ 0x01 ///< can read from the buffer
98 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
99 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
100 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
101 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
105 * Add a new reference to a picture.
106 * @param ref an existing reference to the picture
107 * @param pmask a bitmask containing the allowable permissions in the new
109 * @return a new reference to the picture with the same properties as the
110 * old, excluding any permissions denied by pmask
112 AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
115 * Remove a reference to a picture. If this is the last reference to the
116 * picture, the picture itself is also automatically freed.
117 * @param ref reference to the picture
119 void avfilter_unref_pic(AVFilterPicRef *ref);
122 * A list of supported formats for one end of a filter link. This is used
123 * during the format negotiation process to try to pick the best format to
124 * use to minimize the number of necessary conversions. Each filter gives a
125 * list of the formats supported by each input and output pad. The list
126 * given for each pad need not be distinct - they may be references to the
127 * same list of formats, as is often the case when a filter supports multiple
128 * formats, but will always output the same format as it is given in input.
130 * In this way, a list of possible input formats and a list of possible
131 * output formats are associated with each link. When a set of formats is
132 * negotiated over a link, the input and output lists are merged to form a
133 * new list containing only the common elements of each list. In the case
134 * that there were no common elements, a format conversion is necessary.
135 * Otherwise, the lists are merged, and all other links which reference
136 * either of the format lists involved in the merge are also affected.
138 * For example, consider the filter chain:
139 * filter (a) --> (b) filter (b) --> (c) filter
141 * where the letters in parenthesis indicate a list of formats supported on
142 * the input or output of the link. Suppose the lists are as follows:
147 * First, the first link's lists are merged, yielding:
148 * filter (a) --> (a) filter (a) --> (c) filter
150 * Notice that format list (b) now refers to the same list as filter list (a).
151 * Next, the lists for the second link are merged, yielding:
152 * filter (a) --> (a) filter (a) --> (a) filter
156 * Unfortunately, when the format lists at the two ends of a link are merged,
157 * we must ensure that all links which reference either pre-merge format list
158 * get updated as well. Therefore, we have the format list structure store a
159 * pointer to each of the pointers to itself.
161 typedef struct AVFilterFormats AVFilterFormats;
162 struct AVFilterFormats
164 unsigned format_count; ///< number of formats
165 int *formats; ///< list of formats
167 unsigned refcount; ///< number of references to this list
168 AVFilterFormats ***refs; ///< references to this list
172 * Helper function to create a list of supported formats. This is intended
173 * for use in AVFilter->query_formats().
174 * @param len the number of formats supported
175 * @param ... a list of the supported formats
176 * @return the format list, with no existing references
178 AVFilterFormats *avfilter_make_format_list(int len, ...);
181 * Returns a list of all colorspaces supported by FFmpeg.
183 AVFilterFormats *avfilter_all_colorspaces(void);
186 * Returns a format list which contains the intersection of the formats of
187 * a and b. Also, all the references of a, all the references of b, and
188 * a and b themselves will be deallocated.
190 * If a and b do not share any common formats, neither is modified, and NULL
193 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
196 * Adds *ref as a new reference to formats.
197 * That is the pointers will point like in the ascii art below:
199 * |formats |<--------.
200 * | ____ | ____|___________________
202 * | |* * | | | | | | AVFilterLink
203 * | |* *--------->|*ref|
204 * | |____| | | |____|
205 * |________| |________________________
207 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
210 * Remove *ref as a reference to the format list it currently points to,
211 * deallocate that list if this was the last reference, and set *ref to NULL.
214 * ________ ________ NULL
215 * |formats |<--------. |formats | ^
216 * | ____ | ____|________________ | ____ | ____|________________
217 * | |refs| | | __|_ | |refs| | | __|_
218 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
219 * | |* *--------->|*ref| | |* | | | |*ref|
220 * | |____| | | |____| | |____| | | |____|
221 * |________| |_____________________ |________| |_____________________
223 void avfilter_formats_unref(AVFilterFormats **ref);
229 * |formats |<---------. |formats |<---------.
230 * | ____ | ___|___ | ____ | ___|___
231 * | |refs| | | | | | |refs| | | | | NULL
232 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
233 * | |* * | | |_______| | |* * | | |_______| ___|___
234 * | |____| | | |____| | | | |
235 * |________| |________| |*oldref|
238 void avfilter_formats_changeref(AVFilterFormats **oldref,
239 AVFilterFormats **newref);
242 * A filter pad used for either input or output.
247 * Pad name. The name is unique among inputs and among outputs, but an
248 * input may have the same name as an output. This may be NULL if this
249 * pad has no need to ever be referenced by name.
254 * AVFilterPad type. Only video supported now, hopefully someone will
255 * add audio in the future.
260 * Minimum required permissions on incoming buffers. Any buffers with
261 * insufficient permissions will be automatically copied by the filter
262 * system to a new buffer which provides the needed access permissions.
269 * Permissions which are not accepted on incoming buffers. Any buffer
270 * which has any of these permissions set be automatically copied by the
271 * filter system to a new buffer which does not have those permissions.
272 * This can be used to easily disallow buffers with AV_PERM_REUSE.
279 * Callback called before passing the first slice of a new frame. If
280 * NULL, the filter layer will default to storing a reference to the
281 * picture inside the link structure.
283 * Input video pads only.
285 void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
288 * Callback function to get a buffer. If NULL, the filter system will
289 * handle buffer requests.
291 * Input video pads only.
293 AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms);
296 * Callback called after the slices of a frame are completely sent. If
297 * NULL, the filter layer will default to releasing the reference stored
298 * in the link structure during start_frame().
300 * Input video pads only.
302 void (*end_frame)(AVFilterLink *link);
305 * Slice drawing callback. This is where a filter receives video data
306 * and should do its processing.
308 * Input video pads only.
310 void (*draw_slice)(AVFilterLink *link, int y, int height);
313 * Frame poll callback. This returns the number of immediately available
314 * frames. It should return a positive value if the next request_frame()
315 * is guaranteed to return one frame (with no delay).
317 * Defaults to just calling the source poll_frame() method.
319 * Output video pads only.
321 int (*poll_frame)(AVFilterLink *link);
324 * Frame request callback. A call to this should result in at least one
325 * frame being output over the given link. This should return zero on
326 * success, and another value on error.
328 * Output video pads only.
330 int (*request_frame)(AVFilterLink *link);
333 * Link configuration callback.
335 * For output pads, this should set the link properties such as
336 * width/height. This should NOT set the format property - that is
337 * negotiated between filters by the filter system using the
338 * query_formats() callback before this function is called.
340 * For input pads, this should check the properties of the link, and update
341 * the filter's internal state as necessary.
343 * For both input and output filters, this should return zero on success,
344 * and another value on error.
346 int (*config_props)(AVFilterLink *link);
349 /** Default handler for start_frame() for video inputs */
350 void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
351 /** Default handler for end_frame() for video inputs */
352 void avfilter_default_end_frame(AVFilterLink *link);
353 /** Default handler for config_props() for video outputs */
354 int avfilter_default_config_output_link(AVFilterLink *link);
355 /** Default handler for config_props() for video inputs */
356 int avfilter_default_config_input_link (AVFilterLink *link);
357 /** Default handler for get_video_buffer() for video inputs */
358 AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
361 * A helper for query_formats() which sets all links to the same list of
362 * formats. If there are no links hooked to this filter, the list of formats is
365 void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
366 /** Default handler for query_formats() */
367 int avfilter_default_query_formats(AVFilterContext *ctx);
370 * Filter definition. This defines the pads a filter contains, and all the
371 * callback functions used to interact with the filter.
375 const char *name; ///< filter name
377 int priv_size; ///< size of private data to allocate for the filter
380 * Filter initialization function. Args contains the user-supplied
381 * parameters. FIXME: maybe an AVOption-based system would be better?
382 * opaque is data provided by the code requesting creation of the filter,
383 * and is used to pass data to the filter.
385 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
388 * Filter uninitialization function. Should deallocate any memory held
389 * by the filter, release any picture references, etc. This does not need
390 * to deallocate the AVFilterContext->priv memory itself.
392 void (*uninit)(AVFilterContext *ctx);
395 * Query formats supported by the filter and its pads. Should set the
396 * in_formats for links connected to its output pads, and out_formats
397 * for links connected to its input pads.
399 * Should return zero on success.
401 int (*query_formats)(AVFilterContext *);
403 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
404 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
407 /** An instance of a filter */
408 struct AVFilterContext
410 const AVClass *av_class; ///< needed for av_log()
412 AVFilter *filter; ///< the AVFilter of which this is an instance
414 char *name; ///< name of this filter instance
416 unsigned input_count; ///< number of input pads
417 AVFilterPad *input_pads; ///< array of input pads
418 AVFilterLink **inputs; ///< array of pointers to input links
420 unsigned output_count; ///< number of output pads
421 AVFilterPad *output_pads; ///< array of output pads
422 AVFilterLink **outputs; ///< array of pointers to output links
424 void *priv; ///< private data for use by the filter
428 * A link between two filters. This contains pointers to the source and
429 * destination filters between which this link exists, and the indexes of
430 * the pads involved. In addition, this link also contains the parameters
431 * which have been negotiated and agreed upon between the filter, such as
432 * image dimensions, format, etc
436 AVFilterContext *src; ///< source filter
437 unsigned int srcpad; ///< index of the output pad on the source filter
439 AVFilterContext *dst; ///< dest filter
440 unsigned int dstpad; ///< index of the input pad on the dest filter
442 /** stage of the initialization of the link properties (dimensions, etc) */
444 AVLINK_UNINIT = 0, ///< not started
445 AVLINK_STARTINIT, ///< started, but incomplete
446 AVLINK_INIT ///< complete
449 int w; ///< agreed upon image width
450 int h; ///< agreed upon image height
451 enum PixelFormat format; ///< agreed upon image colorspace
454 * Lists of formats supported by the input and output filters respectively.
455 * These lists are used for negotiating the format to actually be used,
456 * which will be loaded into the format member, above, when chosen.
458 AVFilterFormats *in_formats;
459 AVFilterFormats *out_formats;
462 * The picture reference currently being sent across the link by the source
463 * filter. This is used internally by the filter system to allow
464 * automatic copying of pictures which do not have sufficient permissions
465 * for the destination. This should not be accessed directly by the
468 AVFilterPicRef *srcpic;
470 AVFilterPicRef *cur_pic;
471 AVFilterPicRef *outpic;
475 * Link two filters together.
476 * @param src the source filter
477 * @param srcpad index of the output pad on the source filter
478 * @param dst the destination filter
479 * @param dstpad index of the input pad on the destination filter
480 * @return zero on success
482 int avfilter_link(AVFilterContext *src, unsigned srcpad,
483 AVFilterContext *dst, unsigned dstpad);
486 * Negotiate the colorspace, dimensions, etc of all inputs to a filter.
487 * @param filter the filter to negotiate the properties for its inputs
488 * @return zero on successful negotiation
490 int avfilter_config_links(AVFilterContext *filter);
493 * Request a picture buffer with a specific set of permissions
494 * @param link the output link to the filter from which the picture will
496 * @param perms the required access permissions
497 * @return A reference to the picture. This must be unreferenced with
498 * avfilter_unref_pic when you are finished with it.
500 AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);
503 * Request an input frame from the filter at the other end of the link.
504 * @param link the input link
505 * @return zero on success
507 int avfilter_request_frame(AVFilterLink *link);
510 * Poll a frame from the filter chain.
511 * @param link the input link
512 * @return the number of imediately available frames
514 int avfilter_poll_frame(AVFilterLink *link);
517 * Notify the next filter of the start of a frame.
518 * @param link the output link the frame will be sent over
519 * @param picref A reference to the frame about to be sent. The data for this
520 * frame need only be valid once draw_slice() is called for that
521 * portion. The receiving filter will free this reference when
522 * it no longer needs it.
524 void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
527 * Notify the next filter that the current frame has finished
528 * @param link the output link the frame was sent over
530 void avfilter_end_frame(AVFilterLink *link);
533 * Send a slice to the next filter.
534 * @param link the output link over which the frame is being sent
535 * @param y offset in pixels from the top of the image for this slice
536 * @param h height of this slice in pixels
538 void avfilter_draw_slice(AVFilterLink *link, int y, int h);
540 /** Initialize the filter system. Registers all builtin filters */
541 void avfilter_register_all(void);
543 /** Uninitialize the filter system. Unregisters all filters */
544 void avfilter_uninit(void);
547 * Register a filter. This is only needed if you plan to use
548 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
549 * filter can still by instantiated with avfilter_open even if it is not
551 * @param filter the filter to register
553 void avfilter_register(AVFilter *filter);
556 * Gets a filter definition matching the given name.
557 * @param name the filter name to find
558 * @return the filter definition, if any matching one is registered.
559 * NULL if none found.
561 AVFilter *avfilter_get_by_name(const char *name);
564 * Create a filter instance.
565 * @param filter the filter to create an instance of
566 * @param inst_name Name to give to the new instance. Can be NULL for none.
567 * @return Pointer to the new instance on success. NULL on failure.
569 AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
572 * Initialize a filter.
573 * @param filter the filter to initialize
574 * @param args A string of parameters to use when initializing the filter.
575 * The format and meaning of this string varies by filter.
576 * @param opaque Any extra non-string data needed by the filter. The meaning
577 * of this parameter varies by filter.
578 * @return zero on success
580 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
584 * @param filter the filter to destroy
586 void avfilter_destroy(AVFilterContext *filter);
589 * Insert a filter in the middle of an existing link.
590 * @param link the link into which the filter should be inserted
591 * @param filt the filter to be inserted
592 * @param in the input pad on the filter to connect
593 * @param out the output pad on the filter to connect
594 * @return zero on success
596 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
597 unsigned in, unsigned out);
601 * @param idx Insertion point. Pad is inserted at the end if this point
602 * is beyond the end of the list of pads.
603 * @param count Pointer to the number of pads in the list
604 * @param padidx_off Offset within an AVFilterLink structure to the element
605 * to increment when inserting a new pad causes link
606 * numbering to change
607 * @param pads Pointer to the pointer to the beginning of the list of pads
608 * @param links Pointer to the pointer to the beginning of the list of links
609 * @param newpad The new pad to add. A copy is made when adding.
611 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
612 AVFilterPad **pads, AVFilterLink ***links,
613 AVFilterPad *newpad);
615 /** insert a new input pad for the filter */
616 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
619 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
620 &f->input_pads, &f->inputs, p);
623 /** insert a new output pad for the filter */
624 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
627 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
628 &f->output_pads, &f->outputs, p);
631 #endif /* FFMPEG_AVFILTER_H */