3 * Copyright (c) 2007 Bobby Bingham
5 * This file is part of Libav.
7 * Libav 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 * Libav 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 Libav; 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"
26 #include "libavutil/log.h"
27 #include "libavutil/samplefmt.h"
28 #include "libavutil/pixfmt.h"
29 #include "libavutil/rational.h"
30 #include "libavcodec/avcodec.h"
34 #include "libavfilter/version.h"
37 * Return the LIBAVFILTER_VERSION_INT constant.
39 unsigned avfilter_version(void);
42 * Return the libavfilter build-time configuration.
44 const char *avfilter_configuration(void);
47 * Return the libavfilter license.
49 const char *avfilter_license(void);
52 typedef struct AVFilterContext AVFilterContext;
53 typedef struct AVFilterLink AVFilterLink;
54 typedef struct AVFilterPad AVFilterPad;
55 typedef struct AVFilterFormats AVFilterFormats;
58 * A reference-counted buffer data type used by the filter system. Filters
59 * should not store pointers to this structure directly, but instead use the
60 * AVFilterBufferRef structure below.
62 typedef struct AVFilterBuffer {
63 uint8_t *data[8]; ///< buffer data for each plane/channel
64 int linesize[8]; ///< number of bytes per line
66 unsigned refcount; ///< number of references to this buffer
68 /** private data to be used by a custom free function */
71 * A pointer to the function to deallocate this buffer if the default
72 * function is not sufficient. This could, for example, add the memory
73 * back into a memory pool to be reused later without the overhead of
74 * reallocating it from scratch.
76 void (*free)(struct AVFilterBuffer *buf);
78 int format; ///< media format
79 int w, h; ///< width and height of the allocated buffer
82 * pointers to the data planes/channels.
84 * For video, this should simply point to data[].
86 * For planar audio, each channel has a separate data pointer, and
87 * linesize[0] contains the size of each channel buffer.
88 * For packed audio, there is just one data pointer, and linesize[0]
89 * contains the total size of the buffer for all channels.
91 * Note: Both data and extended_data will always be set, but for planar
92 * audio with more channels that can fit in data, extended_data must be used
93 * in order to access all channels.
95 uint8_t **extended_data;
98 #define AV_PERM_READ 0x01 ///< can read from the buffer
99 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
100 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
101 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
102 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
103 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
106 * Audio specific properties in a reference to an AVFilterBuffer. Since
107 * AVFilterBufferRef is common to different media formats, audio specific
108 * per reference properties must be separated out.
110 typedef struct AVFilterBufferRefAudioProps {
111 uint64_t channel_layout; ///< channel layout of audio buffer
112 int nb_samples; ///< number of audio samples
113 int sample_rate; ///< audio buffer sample rate
114 int planar; ///< audio buffer - planar or packed
115 } AVFilterBufferRefAudioProps;
118 * Video specific properties in a reference to an AVFilterBuffer. Since
119 * AVFilterBufferRef is common to different media formats, video specific
120 * per reference properties must be separated out.
122 typedef struct AVFilterBufferRefVideoProps {
123 int w; ///< image width
124 int h; ///< image height
125 AVRational pixel_aspect; ///< pixel aspect ratio
126 int interlaced; ///< is frame interlaced
127 int top_field_first; ///< field order
128 enum AVPictureType pict_type; ///< picture type of the frame
129 int key_frame; ///< 1 -> keyframe, 0-> not
130 } AVFilterBufferRefVideoProps;
133 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
134 * a buffer to, for example, crop image without any memcpy, the buffer origin
135 * and dimensions are per-reference properties. Linesize is also useful for
136 * image flipping, frame to field filters, etc, and so is also per-reference.
138 * TODO: add anything necessary for frame reordering
140 typedef struct AVFilterBufferRef {
141 AVFilterBuffer *buf; ///< the buffer that this is a reference to
142 uint8_t *data[8]; ///< picture/audio data for each plane
143 int linesize[8]; ///< number of bytes per line
144 int format; ///< media format
147 * presentation timestamp. The time unit may change during
148 * filtering, as it is specified in the link and the filter code
149 * may need to rescale the PTS accordingly.
152 int64_t pos; ///< byte position in stream, -1 if unknown
154 int perms; ///< permissions, see the AV_PERM_* flags
156 enum AVMediaType type; ///< media type of buffer data
157 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
158 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
161 * pointers to the data planes/channels.
163 * For video, this should simply point to data[].
165 * For planar audio, each channel has a separate data pointer, and
166 * linesize[0] contains the size of each channel buffer.
167 * For packed audio, there is just one data pointer, and linesize[0]
168 * contains the total size of the buffer for all channels.
170 * Note: Both data and extended_data will always be set, but for planar
171 * audio with more channels that can fit in data, extended_data must be used
172 * in order to access all channels.
174 uint8_t **extended_data;
178 * Copy properties of src to dst, without copying the actual data
180 void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src);
183 * Add a new reference to a buffer.
185 * @param ref an existing reference to the buffer
186 * @param pmask a bitmask containing the allowable permissions in the new
188 * @return a new reference to the buffer with the same properties as the
189 * old, excluding any permissions denied by pmask
191 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
194 * Remove a reference to a buffer. If this is the last reference to the
195 * buffer, the buffer itself is also automatically freed.
197 * @param ref reference to the buffer, may be NULL
199 void avfilter_unref_buffer(AVFilterBufferRef *ref);
201 #if FF_API_FILTERS_PUBLIC
203 * @addtogroup lavfi_deprecated
204 * @deprecated Those functions are only useful inside filters and
205 * user filters are not supported at this point.
208 struct AVFilterFormats {
209 unsigned format_count; ///< number of formats
210 int *formats; ///< list of media formats
212 unsigned refcount; ///< number of references to this list
213 struct AVFilterFormats ***refs; ///< references to this list
217 AVFilterFormats *avfilter_make_format_list(const int *fmts);
219 int avfilter_add_format(AVFilterFormats **avff, int fmt);
221 AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
223 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
225 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
227 void avfilter_formats_unref(AVFilterFormats **ref);
229 void avfilter_formats_changeref(AVFilterFormats **oldref,
230 AVFilterFormats **newref);
232 void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
239 * A filter pad used for either input or output.
243 * Pad name. The name is unique among inputs and among outputs, but an
244 * input may have the same name as an output. This may be NULL if this
245 * pad has no need to ever be referenced by name.
252 enum AVMediaType type;
255 * Minimum required permissions on incoming buffers. Any buffer with
256 * insufficient permissions will be automatically copied by the filter
257 * system to a new buffer which provides the needed access permissions.
264 * Permissions which are not accepted on incoming buffers. Any buffer
265 * which has any of these permissions set will be automatically copied
266 * by the filter system to a new buffer which does not have those
267 * permissions. This can be used to easily disallow buffers with
275 * Callback called before passing the first slice of a new frame. If
276 * NULL, the filter layer will default to storing a reference to the
277 * picture inside the link structure.
279 * Input video pads only.
281 void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
284 * Callback function to get a video buffer. If NULL, the filter system will
285 * use avfilter_default_get_video_buffer().
287 * Input video pads only.
289 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
292 * Callback function to get an audio buffer. If NULL, the filter system will
293 * use avfilter_default_get_audio_buffer().
295 * Input audio pads only.
297 AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms,
301 * Callback called after the slices of a frame are completely sent. If
302 * NULL, the filter layer will default to releasing the reference stored
303 * in the link structure during start_frame().
305 * Input video pads only.
307 void (*end_frame)(AVFilterLink *link);
310 * Slice drawing callback. This is where a filter receives video data
311 * and should do its processing.
313 * Input video pads only.
315 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
318 * Samples filtering callback. This is where a filter receives audio data
319 * and should do its processing.
321 * Input audio pads only.
323 void (*filter_samples)(AVFilterLink *link, AVFilterBufferRef *samplesref);
326 * Frame poll callback. This returns the number of immediately available
327 * samples. It should return a positive value if the next request_frame()
328 * is guaranteed to return one frame (with no delay).
330 * Defaults to just calling the source poll_frame() method.
334 int (*poll_frame)(AVFilterLink *link);
337 * Frame request callback. A call to this should result in at least one
338 * frame being output over the given link. This should return zero on
339 * success, and another value on error.
343 int (*request_frame)(AVFilterLink *link);
346 * Link configuration callback.
348 * For output pads, this should set the link properties such as
349 * width/height. This should NOT set the format property - that is
350 * negotiated between filters by the filter system using the
351 * query_formats() callback before this function is called.
353 * For input pads, this should check the properties of the link, and update
354 * the filter's internal state as necessary.
356 * For both input and output filters, this should return zero on success,
357 * and another value on error.
359 int (*config_props)(AVFilterLink *link);
362 #if FF_API_FILTERS_PUBLIC
363 /** default handler for start_frame() for video inputs */
365 void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
367 /** default handler for draw_slice() for video inputs */
369 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
371 /** default handler for end_frame() for video inputs */
373 void avfilter_default_end_frame(AVFilterLink *link);
375 #if FF_API_DEFAULT_CONFIG_OUTPUT_LINK
376 /** default handler for config_props() for audio/video outputs */
378 int avfilter_default_config_output_link(AVFilterLink *link);
381 /** default handler for get_video_buffer() for video inputs */
383 AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,
384 int perms, int w, int h);
386 /** Default handler for query_formats() */
388 int avfilter_default_query_formats(AVFilterContext *ctx);
391 #if FF_API_FILTERS_PUBLIC
392 /** start_frame() handler for filters which simply pass video along */
394 void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
396 /** draw_slice() handler for filters which simply pass video along */
398 void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
400 /** end_frame() handler for filters which simply pass video along */
402 void avfilter_null_end_frame(AVFilterLink *link);
404 /** get_video_buffer() handler for filters which simply pass video along */
406 AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link,
407 int perms, int w, int h);
411 * Filter definition. This defines the pads a filter contains, and all the
412 * callback functions used to interact with the filter.
414 typedef struct AVFilter {
415 const char *name; ///< filter name
417 int priv_size; ///< size of private data to allocate for the filter
420 * Filter initialization function. Args contains the user-supplied
421 * parameters. FIXME: maybe an AVOption-based system would be better?
422 * opaque is data provided by the code requesting creation of the filter,
423 * and is used to pass data to the filter.
425 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
428 * Filter uninitialization function. Should deallocate any memory held
429 * by the filter, release any buffer references, etc. This does not need
430 * to deallocate the AVFilterContext->priv memory itself.
432 void (*uninit)(AVFilterContext *ctx);
435 * Queries formats supported by the filter and its pads, and sets the
436 * in_formats for links connected to its output pads, and out_formats
437 * for links connected to its input pads.
439 * @return zero on success, a negative value corresponding to an
440 * AVERROR code otherwise
442 int (*query_formats)(AVFilterContext *);
444 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
445 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
448 * A description for the filter. You should use the
449 * NULL_IF_CONFIG_SMALL() macro to define it.
451 const char *description;
454 /** An instance of a filter */
455 struct AVFilterContext {
456 const AVClass *av_class; ///< needed for av_log()
458 AVFilter *filter; ///< the AVFilter of which this is an instance
460 char *name; ///< name of this filter instance
462 unsigned input_count; ///< number of input pads
463 AVFilterPad *input_pads; ///< array of input pads
464 AVFilterLink **inputs; ///< array of pointers to input links
466 unsigned output_count; ///< number of output pads
467 AVFilterPad *output_pads; ///< array of output pads
468 AVFilterLink **outputs; ///< array of pointers to output links
470 void *priv; ///< private data for use by the filter
474 * A link between two filters. This contains pointers to the source and
475 * destination filters between which this link exists, and the indexes of
476 * the pads involved. In addition, this link also contains the parameters
477 * which have been negotiated and agreed upon between the filter, such as
478 * image dimensions, format, etc.
480 struct AVFilterLink {
481 AVFilterContext *src; ///< source filter
482 AVFilterPad *srcpad; ///< output pad on the source filter
484 AVFilterContext *dst; ///< dest filter
485 AVFilterPad *dstpad; ///< input pad on the dest filter
487 /** stage of the initialization of the link properties (dimensions, etc) */
489 AVLINK_UNINIT = 0, ///< not started
490 AVLINK_STARTINIT, ///< started, but incomplete
491 AVLINK_INIT ///< complete
494 enum AVMediaType type; ///< filter media type
496 /* These parameters apply only to video */
497 int w; ///< agreed upon image width
498 int h; ///< agreed upon image height
499 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
500 /* These two parameters apply only to audio */
501 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/audioconvert.h)
502 #if FF_API_SAMPLERATE64
503 int64_t sample_rate; ///< samples per second
505 int sample_rate; ///< samples per second
508 int format; ///< agreed upon media format
511 * Lists of formats supported by the input and output filters respectively.
512 * These lists are used for negotiating the format to actually be used,
513 * which will be loaded into the format member, above, when chosen.
515 AVFilterFormats *in_formats;
516 AVFilterFormats *out_formats;
519 * The buffer reference currently being sent across the link by the source
520 * filter. This is used internally by the filter system to allow
521 * automatic copying of buffers which do not have sufficient permissions
522 * for the destination. This should not be accessed directly by the
525 AVFilterBufferRef *src_buf;
527 AVFilterBufferRef *cur_buf;
528 AVFilterBufferRef *out_buf;
531 * Define the time base used by the PTS of the frames/samples
532 * which will pass through this link.
533 * During the configuration stage, each filter is supposed to
534 * change only the output timebase, while the timebase of the
535 * input link is assumed to be an unchangeable property.
537 AVRational time_base;
539 /*****************************************************************
540 * All fields below this line are not part of the public API. They
541 * may not be used outside of libavfilter and can be changed and
543 * New public fields should be added right above.
544 *****************************************************************
547 * Lists of channel layouts and sample rates used for automatic
550 AVFilterFormats *in_samplerates;
551 AVFilterFormats *out_samplerates;
552 struct AVFilterChannelLayouts *in_channel_layouts;
553 struct AVFilterChannelLayouts *out_channel_layouts;
557 * Link two filters together.
559 * @param src the source filter
560 * @param srcpad index of the output pad on the source filter
561 * @param dst the destination filter
562 * @param dstpad index of the input pad on the destination filter
563 * @return zero on success
565 int avfilter_link(AVFilterContext *src, unsigned srcpad,
566 AVFilterContext *dst, unsigned dstpad);
569 * Negotiate the media format, dimensions, etc of all inputs to a filter.
571 * @param filter the filter to negotiate the properties for its inputs
572 * @return zero on successful negotiation
574 int avfilter_config_links(AVFilterContext *filter);
577 * Request a picture buffer with a specific set of permissions.
579 * @param link the output link to the filter from which the buffer will
581 * @param perms the required access permissions
582 * @param w the minimum width of the buffer to allocate
583 * @param h the minimum height of the buffer to allocate
584 * @return A reference to the buffer. This must be unreferenced with
585 * avfilter_unref_buffer when you are finished with it.
587 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
591 * Create a buffer reference wrapped around an already allocated image
594 * @param data pointers to the planes of the image to reference
595 * @param linesize linesizes for the planes of the image to reference
596 * @param perms the required access permissions
597 * @param w the width of the image specified by the data and linesize arrays
598 * @param h the height of the image specified by the data and linesize arrays
599 * @param format the pixel format of the image specified by the data and linesize arrays
602 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
603 int w, int h, enum PixelFormat format);
606 * Create an audio buffer reference wrapped around an already
607 * allocated samples buffer.
609 * @param data pointers to the samples plane buffers
610 * @param linesize linesize for the samples plane buffers
611 * @param perms the required access permissions
612 * @param nb_samples number of samples per channel
613 * @param sample_fmt the format of each sample in the buffer to allocate
614 * @param channel_layout the channel layout of the buffer
616 AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays(uint8_t **data,
620 enum AVSampleFormat sample_fmt,
621 uint64_t channel_layout);
624 * Request an input frame from the filter at the other end of the link.
626 * @param link the input link
627 * @return zero on success
629 int avfilter_request_frame(AVFilterLink *link);
632 * Poll a frame from the filter chain.
634 * @param link the input link
635 * @return the number of immediately available frames, a negative
636 * number in case of error
638 int avfilter_poll_frame(AVFilterLink *link);
641 * Notify the next filter of the start of a frame.
643 * @param link the output link the frame will be sent over
644 * @param picref A reference to the frame about to be sent. The data for this
645 * frame need only be valid once draw_slice() is called for that
646 * portion. The receiving filter will free this reference when
647 * it no longer needs it.
649 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
652 * Notifie the next filter that the current frame has finished.
654 * @param link the output link the frame was sent over
656 void avfilter_end_frame(AVFilterLink *link);
659 * Send a slice to the next filter.
661 * Slices have to be provided in sequential order, either in
662 * top-bottom or bottom-top order. If slices are provided in
663 * non-sequential order the behavior of the function is undefined.
665 * @param link the output link over which the frame is being sent
666 * @param y offset in pixels from the top of the image for this slice
667 * @param h height of this slice in pixels
668 * @param slice_dir the assumed direction for sending slices,
669 * from the top slice to the bottom slice if the value is 1,
670 * from the bottom slice to the top slice if the value is -1,
671 * for other values the behavior of the function is undefined.
673 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
675 /** Initialize the filter system. Register all builtin filters. */
676 void avfilter_register_all(void);
678 /** Uninitialize the filter system. Unregister all filters. */
679 void avfilter_uninit(void);
682 * Register a filter. This is only needed if you plan to use
683 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
684 * filter can still by instantiated with avfilter_open even if it is not
687 * @param filter the filter to register
688 * @return 0 if the registration was succesfull, a negative value
691 int avfilter_register(AVFilter *filter);
694 * Get a filter definition matching the given name.
696 * @param name the filter name to find
697 * @return the filter definition, if any matching one is registered.
698 * NULL if none found.
700 AVFilter *avfilter_get_by_name(const char *name);
703 * If filter is NULL, returns a pointer to the first registered filter pointer,
704 * if filter is non-NULL, returns the next pointer after filter.
705 * If the returned pointer points to NULL, the last registered filter
706 * was already reached.
708 AVFilter **av_filter_next(AVFilter **filter);
711 * Create a filter instance.
713 * @param filter_ctx put here a pointer to the created filter context
714 * on success, NULL on failure
715 * @param filter the filter to create an instance of
716 * @param inst_name Name to give to the new instance. Can be NULL for none.
717 * @return >= 0 in case of success, a negative error code otherwise
719 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
722 * Initialize a filter.
724 * @param filter the filter to initialize
725 * @param args A string of parameters to use when initializing the filter.
726 * The format and meaning of this string varies by filter.
727 * @param opaque Any extra non-string data needed by the filter. The meaning
728 * of this parameter varies by filter.
729 * @return zero on success
731 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
734 * Free a filter context.
736 * @param filter the filter to free
738 void avfilter_free(AVFilterContext *filter);
741 * Insert a filter in the middle of an existing link.
743 * @param link the link into which the filter should be inserted
744 * @param filt the filter to be inserted
745 * @param filt_srcpad_idx the input pad on the filter to connect
746 * @param filt_dstpad_idx the output pad on the filter to connect
747 * @return zero on success
749 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
750 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
755 * @param idx Insertion point. Pad is inserted at the end if this point
756 * is beyond the end of the list of pads.
757 * @param count Pointer to the number of pads in the list
758 * @param padidx_off Offset within an AVFilterLink structure to the element
759 * to increment when inserting a new pad causes link
760 * numbering to change
761 * @param pads Pointer to the pointer to the beginning of the list of pads
762 * @param links Pointer to the pointer to the beginning of the list of links
763 * @param newpad The new pad to add. A copy is made when adding.
765 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
766 AVFilterPad **pads, AVFilterLink ***links,
767 AVFilterPad *newpad);
769 /** Insert a new input pad for the filter. */
770 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
773 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
774 &f->input_pads, &f->inputs, p);
777 /** Insert a new output pad for the filter. */
778 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
781 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
782 &f->output_pads, &f->outputs, p);
786 * Copy the frame properties of src to dst, without copying the actual
789 * @return 0 on success, a negative number on error.
791 int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src);
794 * Copy the frame properties and data pointers of src to dst, without copying
797 * @return 0 on success, a negative number on error.
799 int avfilter_copy_buf_props(AVFrame *dst, const AVFilterBufferRef *src);
801 #endif /* AVFILTER_AVFILTER_H */