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
28 * Main libavfilter public API header
32 * @defgroup lavfi Libavfilter - graph-based frame editing library
36 #include "libavutil/attributes.h"
37 #include "libavutil/avutil.h"
38 #include "libavutil/frame.h"
39 #include "libavutil/log.h"
40 #include "libavutil/samplefmt.h"
41 #include "libavutil/pixfmt.h"
42 #include "libavutil/rational.h"
43 #include "libavcodec/avcodec.h"
47 #include "libavfilter/version.h"
50 * Return the LIBAVFILTER_VERSION_INT constant.
52 unsigned avfilter_version(void);
55 * Return the libavfilter build-time configuration.
57 const char *avfilter_configuration(void);
60 * Return the libavfilter license.
62 const char *avfilter_license(void);
65 typedef struct AVFilterContext AVFilterContext;
66 typedef struct AVFilterLink AVFilterLink;
67 typedef struct AVFilterPad AVFilterPad;
68 typedef struct AVFilterFormats AVFilterFormats;
70 #if FF_API_AVFILTERBUFFER
72 * A reference-counted buffer data type used by the filter system. Filters
73 * should not store pointers to this structure directly, but instead use the
74 * AVFilterBufferRef structure below.
76 typedef struct AVFilterBuffer {
77 uint8_t *data[8]; ///< buffer data for each plane/channel
80 * pointers to the data planes/channels.
82 * For video, this should simply point to data[].
84 * For planar audio, each channel has a separate data pointer, and
85 * linesize[0] contains the size of each channel buffer.
86 * For packed audio, there is just one data pointer, and linesize[0]
87 * contains the total size of the buffer for all channels.
89 * Note: Both data and extended_data will always be set, but for planar
90 * audio with more channels that can fit in data, extended_data must be used
91 * in order to access all channels.
93 uint8_t **extended_data;
94 int linesize[8]; ///< number of bytes per line
96 /** private data to be used by a custom free function */
99 * A pointer to the function to deallocate this buffer if the default
100 * function is not sufficient. This could, for example, add the memory
101 * back into a memory pool to be reused later without the overhead of
102 * reallocating it from scratch.
104 void (*free)(struct AVFilterBuffer *buf);
106 int format; ///< media format
107 int w, h; ///< width and height of the allocated buffer
108 unsigned refcount; ///< number of references to this buffer
111 #define AV_PERM_READ 0x01 ///< can read from the buffer
112 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
113 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
114 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
115 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
116 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
119 * Audio specific properties in a reference to an AVFilterBuffer. Since
120 * AVFilterBufferRef is common to different media formats, audio specific
121 * per reference properties must be separated out.
123 typedef struct AVFilterBufferRefAudioProps {
124 uint64_t channel_layout; ///< channel layout of audio buffer
125 int nb_samples; ///< number of audio samples
126 int sample_rate; ///< audio buffer sample rate
127 int planar; ///< audio buffer - planar or packed
128 } AVFilterBufferRefAudioProps;
131 * Video specific properties in a reference to an AVFilterBuffer. Since
132 * AVFilterBufferRef is common to different media formats, video specific
133 * per reference properties must be separated out.
135 typedef struct AVFilterBufferRefVideoProps {
136 int w; ///< image width
137 int h; ///< image height
138 AVRational pixel_aspect; ///< pixel aspect ratio
139 int interlaced; ///< is frame interlaced
140 int top_field_first; ///< field order
141 enum AVPictureType pict_type; ///< picture type of the frame
142 int key_frame; ///< 1 -> keyframe, 0-> not
143 } AVFilterBufferRefVideoProps;
146 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
147 * a buffer to, for example, crop image without any memcpy, the buffer origin
148 * and dimensions are per-reference properties. Linesize is also useful for
149 * image flipping, frame to field filters, etc, and so is also per-reference.
151 * TODO: add anything necessary for frame reordering
153 typedef struct AVFilterBufferRef {
154 AVFilterBuffer *buf; ///< the buffer that this is a reference to
155 uint8_t *data[8]; ///< picture/audio data for each plane
157 * pointers to the data planes/channels.
159 * For video, this should simply point to data[].
161 * For planar audio, each channel has a separate data pointer, and
162 * linesize[0] contains the size of each channel buffer.
163 * For packed audio, there is just one data pointer, and linesize[0]
164 * contains the total size of the buffer for all channels.
166 * Note: Both data and extended_data will always be set, but for planar
167 * audio with more channels that can fit in data, extended_data must be used
168 * in order to access all channels.
170 uint8_t **extended_data;
171 int linesize[8]; ///< number of bytes per line
173 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
174 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
177 * presentation timestamp. The time unit may change during
178 * filtering, as it is specified in the link and the filter code
179 * may need to rescale the PTS accordingly.
182 int64_t pos; ///< byte position in stream, -1 if unknown
184 int format; ///< media format
186 int perms; ///< permissions, see the AV_PERM_* flags
188 enum AVMediaType type; ///< media type of buffer data
192 * Copy properties of src to dst, without copying the actual data
195 void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src);
198 * Add a new reference to a buffer.
200 * @param ref an existing reference to the buffer
201 * @param pmask a bitmask containing the allowable permissions in the new
203 * @return a new reference to the buffer with the same properties as the
204 * old, excluding any permissions denied by pmask
207 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
210 * Remove a reference to a buffer. If this is the last reference to the
211 * buffer, the buffer itself is also automatically freed.
213 * @param ref reference to the buffer, may be NULL
215 * @note it is recommended to use avfilter_unref_bufferp() instead of this
219 void avfilter_unref_buffer(AVFilterBufferRef *ref);
222 * Remove a reference to a buffer and set the pointer to NULL.
223 * If this is the last reference to the buffer, the buffer itself
224 * is also automatically freed.
226 * @param ref pointer to the buffer reference
229 void avfilter_unref_bufferp(AVFilterBufferRef **ref);
232 #if FF_API_AVFILTERPAD_PUBLIC
234 * A filter pad used for either input or output.
236 * @warning this struct will be removed from public API.
237 * users should call avfilter_pad_get_name() and avfilter_pad_get_type()
238 * to access the name and type fields; there should be no need to access
239 * any other fields from outside of libavfilter.
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.
261 attribute_deprecated int min_perms;
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
272 attribute_deprecated int rej_perms;
277 int (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
280 * Callback function to get a video buffer. If NULL, the filter system will
281 * use avfilter_default_get_video_buffer().
283 * Input video pads only.
285 AVFrame *(*get_video_buffer)(AVFilterLink *link, int w, int h);
288 * Callback function to get an audio buffer. If NULL, the filter system will
289 * use avfilter_default_get_audio_buffer().
291 * Input audio pads only.
293 AVFrame *(*get_audio_buffer)(AVFilterLink *link, int nb_samples);
298 int (*end_frame)(AVFilterLink *link);
303 int (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
306 * Filtering callback. This is where a filter receives a frame with
307 * audio/video data and should do its processing.
311 * @return >= 0 on success, a negative AVERROR on error. This function
312 * must ensure that samplesref is properly unreferenced on error if it
313 * hasn't been passed on to another filter.
315 int (*filter_frame)(AVFilterLink *link, AVFrame *frame);
318 * Frame poll callback. This returns the number of immediately available
319 * samples. It should return a positive value if the next request_frame()
320 * is guaranteed to return one frame (with no delay).
322 * Defaults to just calling the source poll_frame() method.
326 int (*poll_frame)(AVFilterLink *link);
329 * Frame request callback. A call to this should result in at least one
330 * frame being output over the given link. This should return zero on
331 * success, and another value on error.
335 int (*request_frame)(AVFilterLink *link);
338 * Link configuration callback.
340 * For output pads, this should set the link properties such as
341 * width/height. This should NOT set the format property - that is
342 * negotiated between filters by the filter system using the
343 * query_formats() callback before this function is called.
345 * For input pads, this should check the properties of the link, and update
346 * the filter's internal state as necessary.
348 * For both input and output filters, this should return zero on success,
349 * and another value on error.
351 int (*config_props)(AVFilterLink *link);
354 * The filter expects a fifo to be inserted on its input link,
355 * typically because it has a delay.
362 * The filter expects writable frames from its input link,
363 * duplicating data buffers if needed.
372 * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
373 * AVFilter.inputs/outputs).
375 int avfilter_pad_count(const AVFilterPad *pads);
378 * Get the name of an AVFilterPad.
380 * @param pads an array of AVFilterPads
381 * @param pad_idx index of the pad in the array it; is the caller's
382 * responsibility to ensure the index is valid
384 * @return name of the pad_idx'th pad in pads
386 const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
389 * Get the type of an AVFilterPad.
391 * @param pads an array of AVFilterPads
392 * @param pad_idx index of the pad in the array; it is the caller's
393 * responsibility to ensure the index is valid
395 * @return type of the pad_idx'th pad in pads
397 enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
400 * The number of the filter inputs is not determined just by AVFilter.inputs.
401 * The filter might add additional inputs during initialization depending on the
402 * options supplied to it.
404 #define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
406 * The number of the filter outputs is not determined just by AVFilter.outputs.
407 * The filter might add additional outputs during initialization depending on
408 * the options supplied to it.
410 #define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
412 * The filter supports multithreading by splitting frames into multiple parts
413 * and processing them concurrently.
415 #define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
418 * Filter definition. This defines the pads a filter contains, and all the
419 * callback functions used to interact with the filter.
421 typedef struct AVFilter {
423 * Filter name. Must be non-NULL and unique among filters.
428 * A description of the filter. May be NULL.
430 * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
432 const char *description;
435 * List of inputs, terminated by a zeroed element.
437 * NULL if there are no (static) inputs. Instances of filters with
438 * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in
441 const AVFilterPad *inputs;
443 * List of outputs, terminated by a zeroed element.
445 * NULL if there are no (static) outputs. Instances of filters with
446 * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in
449 const AVFilterPad *outputs;
452 * A class for the private data, used to declare filter private AVOptions.
453 * This field is NULL for filters that do not declare any options.
455 * If this field is non-NULL, the first member of the filter private data
456 * must be a pointer to AVClass, which will be set by libavfilter generic
457 * code to this class.
459 const AVClass *priv_class;
462 * A combination of AVFILTER_FLAG_*
466 /*****************************************************************
467 * All fields below this line are not part of the public API. They
468 * may not be used outside of libavfilter and can be changed and
470 * New public fields should be added right above.
471 *****************************************************************
475 * Filter initialization function.
477 * This callback will be called only once during the filter lifetime, after
478 * all the options have been set, but before links between filters are
479 * established and format negotiation is done.
481 * Basic filter initialization should be done here. Filters with dynamic
482 * inputs and/or outputs should create those inputs/outputs here based on
483 * provided options. No more changes to this filter's inputs/outputs can be
484 * done after this callback.
486 * This callback must not assume that the filter links exist or frame
487 * parameters are known.
489 * @ref AVFilter.uninit "uninit" is guaranteed to be called even if
490 * initialization fails, so this callback does not have to clean up on
493 * @return 0 on success, a negative AVERROR on failure
495 int (*init)(AVFilterContext *ctx);
498 * Should be set instead of @ref AVFilter.init "init" by the filters that
499 * want to pass a dictionary of AVOptions to nested contexts that are
500 * allocated during init.
502 * On return, the options dict should be freed and replaced with one that
503 * contains all the options which could not be processed by this filter (or
504 * with NULL if all the options were processed).
506 * Otherwise the semantics is the same as for @ref AVFilter.init "init".
508 int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
511 * Filter uninitialization function.
513 * Called only once right before the filter is freed. Should deallocate any
514 * memory held by the filter, release any buffer references, etc. It does
515 * not need to deallocate the AVFilterContext.priv memory itself.
517 * This callback may be called even if @ref AVFilter.init "init" was not
518 * called or failed, so it must be prepared to handle such a situation.
520 void (*uninit)(AVFilterContext *ctx);
523 * Query formats supported by the filter on its inputs and outputs.
525 * This callback is called after the filter is initialized (so the inputs
526 * and outputs are fixed), shortly before the format negotiation. This
527 * callback may be called more than once.
529 * This callback must set AVFilterLink.out_formats on every input link and
530 * AVFilterLink.in_formats on every output link to a list of pixel/sample
531 * formats that the filter supports on that link. For audio links, this
532 * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" /
533 * @ref AVFilterLink.out_samplerates "out_samplerates" and
534 * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" /
535 * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously.
537 * This callback may be NULL for filters with one input, in which case
538 * libavfilter assumes that it supports all input formats and preserves
541 * @return zero on success, a negative value corresponding to an
542 * AVERROR code otherwise
544 int (*query_formats)(AVFilterContext *);
546 int priv_size; ///< size of private data to allocate for the filter
549 * Used by the filter registration system. Must not be touched by any other
552 struct AVFilter *next;
556 * Process multiple parts of the frame concurrently.
558 #define AVFILTER_THREAD_SLICE (1 << 0)
560 typedef struct AVFilterInternal AVFilterInternal;
562 /** An instance of a filter */
563 struct AVFilterContext {
564 const AVClass *av_class; ///< needed for av_log()
566 const AVFilter *filter; ///< the AVFilter of which this is an instance
568 char *name; ///< name of this filter instance
570 AVFilterPad *input_pads; ///< array of input pads
571 AVFilterLink **inputs; ///< array of pointers to input links
573 attribute_deprecated unsigned input_count; ///< @deprecated use nb_inputs
575 unsigned nb_inputs; ///< number of input pads
577 AVFilterPad *output_pads; ///< array of output pads
578 AVFilterLink **outputs; ///< array of pointers to output links
580 attribute_deprecated unsigned output_count; ///< @deprecated use nb_outputs
582 unsigned nb_outputs; ///< number of output pads
584 void *priv; ///< private data for use by the filter
586 struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
589 * Type of multithreading being allowed/used. A combination of
590 * AVFILTER_THREAD_* flags.
592 * May be set by the caller before initializing the filter to forbid some
593 * or all kinds of multithreading for this filter. The default is allowing
596 * When the filter is initialized, this field is combined using bit AND with
597 * AVFilterGraph.thread_type to get the final mask used for determining
598 * allowed threading types. I.e. a threading type needs to be set in both
601 * After the filter is initialzed, libavfilter sets this field to the
602 * threading type that is actually used (0 for no multithreading).
607 * An opaque struct for libavfilter internal use.
609 AVFilterInternal *internal;
613 * A link between two filters. This contains pointers to the source and
614 * destination filters between which this link exists, and the indexes of
615 * the pads involved. In addition, this link also contains the parameters
616 * which have been negotiated and agreed upon between the filter, such as
617 * image dimensions, format, etc.
619 struct AVFilterLink {
620 AVFilterContext *src; ///< source filter
621 AVFilterPad *srcpad; ///< output pad on the source filter
623 AVFilterContext *dst; ///< dest filter
624 AVFilterPad *dstpad; ///< input pad on the dest filter
626 enum AVMediaType type; ///< filter media type
628 /* These parameters apply only to video */
629 int w; ///< agreed upon image width
630 int h; ///< agreed upon image height
631 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
632 /* These two parameters apply only to audio */
633 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
634 int sample_rate; ///< samples per second
636 int format; ///< agreed upon media format
639 * Define the time base used by the PTS of the frames/samples
640 * which will pass through this link.
641 * During the configuration stage, each filter is supposed to
642 * change only the output timebase, while the timebase of the
643 * input link is assumed to be an unchangeable property.
645 AVRational time_base;
647 /*****************************************************************
648 * All fields below this line are not part of the public API. They
649 * may not be used outside of libavfilter and can be changed and
651 * New public fields should be added right above.
652 *****************************************************************
655 * Lists of formats supported by the input and output filters respectively.
656 * These lists are used for negotiating the format to actually be used,
657 * which will be loaded into the format member, above, when chosen.
659 AVFilterFormats *in_formats;
660 AVFilterFormats *out_formats;
663 * Lists of channel layouts and sample rates used for automatic
666 AVFilterFormats *in_samplerates;
667 AVFilterFormats *out_samplerates;
668 struct AVFilterChannelLayouts *in_channel_layouts;
669 struct AVFilterChannelLayouts *out_channel_layouts;
672 * Audio only, the destination filter sets this to a non-zero value to
673 * request that buffers with the given number of samples should be sent to
674 * it. AVFilterPad.needs_fifo must also be set on the corresponding input
676 * Last buffer before EOF will be padded with silence.
680 /** stage of the initialization of the link properties (dimensions, etc) */
682 AVLINK_UNINIT = 0, ///< not started
683 AVLINK_STARTINIT, ///< started, but incomplete
684 AVLINK_INIT ///< complete
689 * Link two filters together.
691 * @param src the source filter
692 * @param srcpad index of the output pad on the source filter
693 * @param dst the destination filter
694 * @param dstpad index of the input pad on the destination filter
695 * @return zero on success
697 int avfilter_link(AVFilterContext *src, unsigned srcpad,
698 AVFilterContext *dst, unsigned dstpad);
701 * Negotiate the media format, dimensions, etc of all inputs to a filter.
703 * @param filter the filter to negotiate the properties for its inputs
704 * @return zero on successful negotiation
706 int avfilter_config_links(AVFilterContext *filter);
708 #if FF_API_AVFILTERBUFFER
710 * Create a buffer reference wrapped around an already allocated image
713 * @param data pointers to the planes of the image to reference
714 * @param linesize linesizes for the planes of the image to reference
715 * @param perms the required access permissions
716 * @param w the width of the image specified by the data and linesize arrays
717 * @param h the height of the image specified by the data and linesize arrays
718 * @param format the pixel format of the image specified by the data and linesize arrays
722 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
723 int w, int h, enum AVPixelFormat format);
726 * Create an audio buffer reference wrapped around an already
727 * allocated samples buffer.
729 * @param data pointers to the samples plane buffers
730 * @param linesize linesize for the samples plane buffers
731 * @param perms the required access permissions
732 * @param nb_samples number of samples per channel
733 * @param sample_fmt the format of each sample in the buffer to allocate
734 * @param channel_layout the channel layout of the buffer
737 AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays(uint8_t **data,
741 enum AVSampleFormat sample_fmt,
742 uint64_t channel_layout);
745 /** Initialize the filter system. Register all builtin filters. */
746 void avfilter_register_all(void);
748 #if FF_API_OLD_FILTER_REGISTER
749 /** Uninitialize the filter system. Unregister all filters. */
751 void avfilter_uninit(void);
755 * Register a filter. This is only needed if you plan to use
756 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
757 * filter can still by instantiated with avfilter_graph_alloc_filter even if it
760 * @param filter the filter to register
761 * @return 0 if the registration was succesfull, a negative value
764 int avfilter_register(AVFilter *filter);
767 * Get a filter definition matching the given name.
769 * @param name the filter name to find
770 * @return the filter definition, if any matching one is registered.
771 * NULL if none found.
773 #if !FF_API_NOCONST_GET_NAME
776 AVFilter *avfilter_get_by_name(const char *name);
779 * Iterate over all registered filters.
780 * @return If prev is non-NULL, next registered filter after prev or NULL if
781 * prev is the last filter. If prev is NULL, return the first registered filter.
783 const AVFilter *avfilter_next(const AVFilter *prev);
785 #if FF_API_OLD_FILTER_REGISTER
787 * If filter is NULL, returns a pointer to the first registered filter pointer,
788 * if filter is non-NULL, returns the next pointer after filter.
789 * If the returned pointer points to NULL, the last registered filter
790 * was already reached.
791 * @deprecated use avfilter_next()
794 AVFilter **av_filter_next(AVFilter **filter);
797 #if FF_API_AVFILTER_OPEN
799 * Create a filter instance.
801 * @param filter_ctx put here a pointer to the created filter context
802 * on success, NULL on failure
803 * @param filter the filter to create an instance of
804 * @param inst_name Name to give to the new instance. Can be NULL for none.
805 * @return >= 0 in case of success, a negative error code otherwise
806 * @deprecated use avfilter_graph_alloc_filter() instead
809 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
813 #if FF_API_AVFILTER_INIT_FILTER
815 * Initialize a filter.
817 * @param filter the filter to initialize
818 * @param args A string of parameters to use when initializing the filter.
819 * The format and meaning of this string varies by filter.
820 * @param opaque Any extra non-string data needed by the filter. The meaning
821 * of this parameter varies by filter.
822 * @return zero on success
825 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
829 * Initialize a filter with the supplied parameters.
831 * @param ctx uninitialized filter context to initialize
832 * @param args Options to initialize the filter with. This must be a
833 * ':'-separated list of options in the 'key=value' form.
834 * May be NULL if the options have been set directly using the
835 * AVOptions API or there are no options that need to be set.
836 * @return 0 on success, a negative AVERROR on failure
838 int avfilter_init_str(AVFilterContext *ctx, const char *args);
841 * Initialize a filter with the supplied dictionary of options.
843 * @param ctx uninitialized filter context to initialize
844 * @param options An AVDictionary filled with options for this filter. On
845 * return this parameter will be destroyed and replaced with
846 * a dict containing options that were not found. This dictionary
847 * must be freed by the caller.
848 * May be NULL, then this function is equivalent to
849 * avfilter_init_str() with the second parameter set to NULL.
850 * @return 0 on success, a negative AVERROR on failure
852 * @note This function and avfilter_init_str() do essentially the same thing,
853 * the difference is in manner in which the options are passed. It is up to the
854 * calling code to choose whichever is more preferable. The two functions also
855 * behave differently when some of the provided options are not declared as
856 * supported by the filter. In such a case, avfilter_init_str() will fail, but
857 * this function will leave those extra options in the options AVDictionary and
860 int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options);
863 * Free a filter context. This will also remove the filter from its
864 * filtergraph's list of filters.
866 * @param filter the filter to free
868 void avfilter_free(AVFilterContext *filter);
871 * Insert a filter in the middle of an existing link.
873 * @param link the link into which the filter should be inserted
874 * @param filt the filter to be inserted
875 * @param filt_srcpad_idx the input pad on the filter to connect
876 * @param filt_dstpad_idx the output pad on the filter to connect
877 * @return zero on success
879 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
880 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
882 #if FF_API_AVFILTERBUFFER
884 * Copy the frame properties of src to dst, without copying the actual
887 * @return 0 on success, a negative number on error.
890 int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src);
893 * Copy the frame properties and data pointers of src to dst, without copying
896 * @return 0 on success, a negative number on error.
899 int avfilter_copy_buf_props(AVFrame *dst, const AVFilterBufferRef *src);
903 * @return AVClass for AVFilterContext.
905 * @see av_opt_find().
907 const AVClass *avfilter_get_class(void);
909 typedef struct AVFilterGraphInternal AVFilterGraphInternal;
912 * A function pointer passed to the @ref AVFilterGraph.execute callback to be
913 * executed multiple times, possibly in parallel.
915 * @param ctx the filter context the job belongs to
916 * @param arg an opaque parameter passed through from @ref
917 * AVFilterGraph.execute
918 * @param jobnr the index of the job being executed
919 * @param nb_jobs the total number of jobs
921 * @return 0 on success, a negative AVERROR on error
923 typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
926 * A function executing multiple jobs, possibly in parallel.
928 * @param ctx the filter context to which the jobs belong
929 * @param func the function to be called multiple times
930 * @param arg the argument to be passed to func
931 * @param ret a nb_jobs-sized array to be filled with return values from each
933 * @param nb_jobs the number of jobs to execute
935 * @return 0 on success, a negative AVERROR on error
937 typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
938 void *arg, int *ret, int nb_jobs);
940 typedef struct AVFilterGraph {
941 const AVClass *av_class;
944 unsigned filter_count;
946 AVFilterContext **filters;
947 #if !FF_API_FOO_COUNT
951 char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
952 char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
958 * Type of multithreading allowed for filters in this graph. A combination
959 * of AVFILTER_THREAD_* flags.
961 * May be set by the caller at any point, the setting will apply to all
962 * filters initialized after that. The default is allowing everything.
964 * When a filter in this graph is initialized, this field is combined using
965 * bit AND with AVFilterContext.thread_type to get the final mask used for
966 * determining allowed threading types. I.e. a threading type needs to be
967 * set in both to be allowed.
972 * Maximum number of threads used by filters in this graph. May be set by
973 * the caller before adding any filters to the filtergraph. Zero (the
974 * default) means that the number of threads is determined automatically.
979 * Opaque object for libavfilter internal use.
981 AVFilterGraphInternal *internal;
984 * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
985 * be used from callbacks like @ref AVFilterGraph.execute.
986 * Libavfilter will not touch this field in any way.
991 * This callback may be set by the caller immediately after allocating the
992 * graph and before adding any filters to it, to provide a custom
993 * multithreading implementation.
995 * If set, filters with slice threading capability will call this callback
996 * to execute multiple jobs in parallel.
998 * If this field is left unset, libavfilter will use its internal
999 * implementation, which may or may not be multithreaded depending on the
1000 * platform and build options.
1002 avfilter_execute_func *execute;
1006 * Allocate a filter graph.
1008 AVFilterGraph *avfilter_graph_alloc(void);
1011 * Create a new filter instance in a filter graph.
1013 * @param graph graph in which the new filter will be used
1014 * @param filter the filter to create an instance of
1015 * @param name Name to give to the new instance (will be copied to
1016 * AVFilterContext.name). This may be used by the caller to identify
1017 * different filters, libavfilter itself assigns no semantics to
1018 * this parameter. May be NULL.
1020 * @return the context of the newly created filter instance (note that it is
1021 * also retrievable directly through AVFilterGraph.filters or with
1022 * avfilter_graph_get_filter()) on success or NULL or failure.
1024 AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
1025 const AVFilter *filter,
1029 * Get a filter instance with name name from graph.
1031 * @return the pointer to the found filter instance or NULL if it
1034 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name);
1036 #if FF_API_AVFILTER_OPEN
1038 * Add an existing filter instance to a filter graph.
1040 * @param graphctx the filter graph
1041 * @param filter the filter to be added
1043 * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a
1046 attribute_deprecated
1047 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
1051 * Create and add a filter instance into an existing graph.
1052 * The filter instance is created from the filter filt and inited
1053 * with the parameters args and opaque.
1055 * In case of success put in *filt_ctx the pointer to the created
1056 * filter instance, otherwise set *filt_ctx to NULL.
1058 * @param name the instance name to give to the created filter instance
1059 * @param graph_ctx the filter graph
1060 * @return a negative AVERROR error code in case of failure, a non
1061 * negative value otherwise
1063 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
1064 const char *name, const char *args, void *opaque,
1065 AVFilterGraph *graph_ctx);
1068 * Check validity and configure all the links and formats in the graph.
1070 * @param graphctx the filter graph
1071 * @param log_ctx context used for logging
1072 * @return 0 in case of success, a negative AVERROR code otherwise
1074 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
1077 * Free a graph, destroy its links, and set *graph to NULL.
1078 * If *graph is NULL, do nothing.
1080 void avfilter_graph_free(AVFilterGraph **graph);
1083 * A linked-list of the inputs/outputs of the filter chain.
1085 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
1086 * where it is used to communicate open (unlinked) inputs and outputs from and
1088 * This struct specifies, per each not connected pad contained in the graph, the
1089 * filter context and the pad index required for establishing a link.
1091 typedef struct AVFilterInOut {
1092 /** unique name for this input/output in the list */
1095 /** filter context associated to this input/output */
1096 AVFilterContext *filter_ctx;
1098 /** index of the filt_ctx pad to use for linking */
1101 /** next input/input in the list, NULL if this is the last */
1102 struct AVFilterInOut *next;
1106 * Allocate a single AVFilterInOut entry.
1107 * Must be freed with avfilter_inout_free().
1108 * @return allocated AVFilterInOut on success, NULL on failure.
1110 AVFilterInOut *avfilter_inout_alloc(void);
1113 * Free the supplied list of AVFilterInOut and set *inout to NULL.
1114 * If *inout is NULL, do nothing.
1116 void avfilter_inout_free(AVFilterInOut **inout);
1119 * Add a graph described by a string to a graph.
1121 * @param graph the filter graph where to link the parsed graph context
1122 * @param filters string to be parsed
1123 * @param inputs linked list to the inputs of the graph
1124 * @param outputs linked list to the outputs of the graph
1125 * @return zero on success, a negative AVERROR code on error
1127 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
1128 AVFilterInOut *inputs, AVFilterInOut *outputs,
1132 * Add a graph described by a string to a graph.
1134 * @param[in] graph the filter graph where to link the parsed graph context
1135 * @param[in] filters string to be parsed
1136 * @param[out] inputs a linked list of all free (unlinked) inputs of the
1137 * parsed graph will be returned here. It is to be freed
1138 * by the caller using avfilter_inout_free().
1139 * @param[out] outputs a linked list of all free (unlinked) outputs of the
1140 * parsed graph will be returned here. It is to be freed by the
1141 * caller using avfilter_inout_free().
1142 * @return zero on success, a negative AVERROR code on error
1144 * @note the difference between avfilter_graph_parse2() and
1145 * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
1146 * the lists of inputs and outputs, which therefore must be known before calling
1147 * the function. On the other hand, avfilter_graph_parse2() \em returns the
1148 * inputs and outputs that are left unlinked after parsing the graph and the
1149 * caller then deals with them. Another difference is that in
1150 * avfilter_graph_parse(), the inputs parameter describes inputs of the
1151 * <em>already existing</em> part of the graph; i.e. from the point of view of
1152 * the newly created part, they are outputs. Similarly the outputs parameter
1153 * describes outputs of the already existing filters, which are provided as
1154 * inputs to the parsed filters.
1155 * avfilter_graph_parse2() takes the opposite approach -- it makes no reference
1156 * whatsoever to already existing parts of the graph and the inputs parameter
1157 * will on return contain inputs of the newly parsed part of the graph.
1158 * Analogously the outputs parameter will contain outputs of the newly created
1161 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
1162 AVFilterInOut **inputs,
1163 AVFilterInOut **outputs);
1169 #endif /* AVFILTER_AVFILTER_H */