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"
46 #include "libavfilter/version.h"
49 * Return the LIBAVFILTER_VERSION_INT constant.
51 unsigned avfilter_version(void);
54 * Return the libavfilter build-time configuration.
56 const char *avfilter_configuration(void);
59 * Return the libavfilter license.
61 const char *avfilter_license(void);
64 typedef struct AVFilterContext AVFilterContext;
65 typedef struct AVFilterLink AVFilterLink;
66 typedef struct AVFilterPad AVFilterPad;
67 typedef struct AVFilterFormats AVFilterFormats;
69 #if FF_API_AVFILTERBUFFER
71 * A reference-counted buffer data type used by the filter system. Filters
72 * should not store pointers to this structure directly, but instead use the
73 * AVFilterBufferRef structure below.
75 typedef struct AVFilterBuffer {
76 uint8_t *data[8]; ///< buffer data for each plane/channel
79 * pointers to the data planes/channels.
81 * For video, this should simply point to data[].
83 * For planar audio, each channel has a separate data pointer, and
84 * linesize[0] contains the size of each channel buffer.
85 * For packed audio, there is just one data pointer, and linesize[0]
86 * contains the total size of the buffer for all channels.
88 * Note: Both data and extended_data will always be set, but for planar
89 * audio with more channels that can fit in data, extended_data must be used
90 * in order to access all channels.
92 uint8_t **extended_data;
93 int linesize[8]; ///< number of bytes per line
95 /** private data to be used by a custom free function */
98 * A pointer to the function to deallocate this buffer if the default
99 * function is not sufficient. This could, for example, add the memory
100 * back into a memory pool to be reused later without the overhead of
101 * reallocating it from scratch.
103 void (*free)(struct AVFilterBuffer *buf);
105 int format; ///< media format
106 int w, h; ///< width and height of the allocated buffer
107 unsigned refcount; ///< number of references to this buffer
110 #define AV_PERM_READ 0x01 ///< can read from the buffer
111 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
112 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
113 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
114 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
115 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
118 * Audio specific properties in a reference to an AVFilterBuffer. Since
119 * AVFilterBufferRef is common to different media formats, audio specific
120 * per reference properties must be separated out.
122 typedef struct AVFilterBufferRefAudioProps {
123 uint64_t channel_layout; ///< channel layout of audio buffer
124 int nb_samples; ///< number of audio samples
125 int sample_rate; ///< audio buffer sample rate
126 int planar; ///< audio buffer - planar or packed
127 } AVFilterBufferRefAudioProps;
130 * Video specific properties in a reference to an AVFilterBuffer. Since
131 * AVFilterBufferRef is common to different media formats, video specific
132 * per reference properties must be separated out.
134 typedef struct AVFilterBufferRefVideoProps {
135 int w; ///< image width
136 int h; ///< image height
137 AVRational pixel_aspect; ///< pixel aspect ratio
138 int interlaced; ///< is frame interlaced
139 int top_field_first; ///< field order
140 enum AVPictureType pict_type; ///< picture type of the frame
141 int key_frame; ///< 1 -> keyframe, 0-> not
142 } AVFilterBufferRefVideoProps;
145 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
146 * a buffer to, for example, crop image without any memcpy, the buffer origin
147 * and dimensions are per-reference properties. Linesize is also useful for
148 * image flipping, frame to field filters, etc, and so is also per-reference.
150 * TODO: add anything necessary for frame reordering
152 typedef struct AVFilterBufferRef {
153 AVFilterBuffer *buf; ///< the buffer that this is a reference to
154 uint8_t *data[8]; ///< picture/audio data for each plane
156 * pointers to the data planes/channels.
158 * For video, this should simply point to data[].
160 * For planar audio, each channel has a separate data pointer, and
161 * linesize[0] contains the size of each channel buffer.
162 * For packed audio, there is just one data pointer, and linesize[0]
163 * contains the total size of the buffer for all channels.
165 * Note: Both data and extended_data will always be set, but for planar
166 * audio with more channels that can fit in data, extended_data must be used
167 * in order to access all channels.
169 uint8_t **extended_data;
170 int linesize[8]; ///< number of bytes per line
172 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
173 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
176 * presentation timestamp. The time unit may change during
177 * filtering, as it is specified in the link and the filter code
178 * may need to rescale the PTS accordingly.
181 int64_t pos; ///< byte position in stream, -1 if unknown
183 int format; ///< media format
185 int perms; ///< permissions, see the AV_PERM_* flags
187 enum AVMediaType type; ///< media type of buffer data
191 * Copy properties of src to dst, without copying the actual data
194 void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src);
197 * Add a new reference to a buffer.
199 * @param ref an existing reference to the buffer
200 * @param pmask a bitmask containing the allowable permissions in the new
202 * @return a new reference to the buffer with the same properties as the
203 * old, excluding any permissions denied by pmask
206 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
209 * Remove a reference to a buffer. If this is the last reference to the
210 * buffer, the buffer itself is also automatically freed.
212 * @param ref reference to the buffer, may be NULL
214 * @note it is recommended to use avfilter_unref_bufferp() instead of this
218 void avfilter_unref_buffer(AVFilterBufferRef *ref);
221 * Remove a reference to a buffer and set the pointer to NULL.
222 * If this is the last reference to the buffer, the buffer itself
223 * is also automatically freed.
225 * @param ref pointer to the buffer reference
228 void avfilter_unref_bufferp(AVFilterBufferRef **ref);
231 #if FF_API_AVFILTERPAD_PUBLIC
233 * A filter pad used for either input or output.
235 * @warning this struct will be removed from public API.
236 * users should call avfilter_pad_get_name() and avfilter_pad_get_type()
237 * to access the name and type fields; there should be no need to access
238 * any other fields from outside of libavfilter.
242 * Pad name. The name is unique among inputs and among outputs, but an
243 * input may have the same name as an output. This may be NULL if this
244 * pad has no need to ever be referenced by name.
251 enum AVMediaType type;
254 * Minimum required permissions on incoming buffers. Any buffer with
255 * insufficient permissions will be automatically copied by the filter
256 * system to a new buffer which provides the needed access permissions.
260 attribute_deprecated int min_perms;
263 * Permissions which are not accepted on incoming buffers. Any buffer
264 * which has any of these permissions set will be automatically copied
265 * by the filter system to a new buffer which does not have those
266 * permissions. This can be used to easily disallow buffers with
271 attribute_deprecated int rej_perms;
276 int (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
279 * Callback function to get a video buffer. If NULL, the filter system will
280 * use avfilter_default_get_video_buffer().
282 * Input video pads only.
284 AVFrame *(*get_video_buffer)(AVFilterLink *link, int w, int h);
287 * Callback function to get an audio buffer. If NULL, the filter system will
288 * use avfilter_default_get_audio_buffer().
290 * Input audio pads only.
292 AVFrame *(*get_audio_buffer)(AVFilterLink *link, int nb_samples);
297 int (*end_frame)(AVFilterLink *link);
302 int (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
305 * Filtering callback. This is where a filter receives a frame with
306 * audio/video data and should do its processing.
310 * @return >= 0 on success, a negative AVERROR on error. This function
311 * must ensure that samplesref is properly unreferenced on error if it
312 * hasn't been passed on to another filter.
314 int (*filter_frame)(AVFilterLink *link, AVFrame *frame);
317 * Frame poll callback. This returns the number of immediately available
318 * samples. It should return a positive value if the next request_frame()
319 * is guaranteed to return one frame (with no delay).
321 * Defaults to just calling the source poll_frame() method.
325 int (*poll_frame)(AVFilterLink *link);
328 * Frame request callback. A call to this should result in at least one
329 * frame being output over the given link. This should return zero on
330 * success, and another value on error.
334 int (*request_frame)(AVFilterLink *link);
337 * Link configuration callback.
339 * For output pads, this should set the link properties such as
340 * width/height. This should NOT set the format property - that is
341 * negotiated between filters by the filter system using the
342 * query_formats() callback before this function is called.
344 * For input pads, this should check the properties of the link, and update
345 * the filter's internal state as necessary.
347 * For both input and output filters, this should return zero on success,
348 * and another value on error.
350 int (*config_props)(AVFilterLink *link);
353 * The filter expects a fifo to be inserted on its input link,
354 * typically because it has a delay.
361 * The filter expects writable frames from its input link,
362 * duplicating data buffers if needed.
371 * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
372 * AVFilter.inputs/outputs).
374 int avfilter_pad_count(const AVFilterPad *pads);
377 * Get the name of an AVFilterPad.
379 * @param pads an array of AVFilterPads
380 * @param pad_idx index of the pad in the array it; is the caller's
381 * responsibility to ensure the index is valid
383 * @return name of the pad_idx'th pad in pads
385 const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
388 * Get the type of an AVFilterPad.
390 * @param pads an array of AVFilterPads
391 * @param pad_idx index of the pad in the array; it is the caller's
392 * responsibility to ensure the index is valid
394 * @return type of the pad_idx'th pad in pads
396 enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
399 * The number of the filter inputs is not determined just by AVFilter.inputs.
400 * The filter might add additional inputs during initialization depending on the
401 * options supplied to it.
403 #define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
405 * The number of the filter outputs is not determined just by AVFilter.outputs.
406 * The filter might add additional outputs during initialization depending on
407 * the options supplied to it.
409 #define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
411 * The filter supports multithreading by splitting frames into multiple parts
412 * and processing them concurrently.
414 #define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
417 * Filter definition. This defines the pads a filter contains, and all the
418 * callback functions used to interact with the filter.
420 typedef struct AVFilter {
422 * Filter name. Must be non-NULL and unique among filters.
427 * A description of the filter. May be NULL.
429 * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
431 const char *description;
434 * List of inputs, terminated by a zeroed element.
436 * NULL if there are no (static) inputs. Instances of filters with
437 * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in
440 const AVFilterPad *inputs;
442 * List of outputs, terminated by a zeroed element.
444 * NULL if there are no (static) outputs. Instances of filters with
445 * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in
448 const AVFilterPad *outputs;
451 * A class for the private data, used to declare filter private AVOptions.
452 * This field is NULL for filters that do not declare any options.
454 * If this field is non-NULL, the first member of the filter private data
455 * must be a pointer to AVClass, which will be set by libavfilter generic
456 * code to this class.
458 const AVClass *priv_class;
461 * A combination of AVFILTER_FLAG_*
465 /*****************************************************************
466 * All fields below this line are not part of the public API. They
467 * may not be used outside of libavfilter and can be changed and
469 * New public fields should be added right above.
470 *****************************************************************
474 * Filter initialization function.
476 * This callback will be called only once during the filter lifetime, after
477 * all the options have been set, but before links between filters are
478 * established and format negotiation is done.
480 * Basic filter initialization should be done here. Filters with dynamic
481 * inputs and/or outputs should create those inputs/outputs here based on
482 * provided options. No more changes to this filter's inputs/outputs can be
483 * done after this callback.
485 * This callback must not assume that the filter links exist or frame
486 * parameters are known.
488 * @ref AVFilter.uninit "uninit" is guaranteed to be called even if
489 * initialization fails, so this callback does not have to clean up on
492 * @return 0 on success, a negative AVERROR on failure
494 int (*init)(AVFilterContext *ctx);
497 * Should be set instead of @ref AVFilter.init "init" by the filters that
498 * want to pass a dictionary of AVOptions to nested contexts that are
499 * allocated during init.
501 * On return, the options dict should be freed and replaced with one that
502 * contains all the options which could not be processed by this filter (or
503 * with NULL if all the options were processed).
505 * Otherwise the semantics is the same as for @ref AVFilter.init "init".
507 int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
510 * Filter uninitialization function.
512 * Called only once right before the filter is freed. Should deallocate any
513 * memory held by the filter, release any buffer references, etc. It does
514 * not need to deallocate the AVFilterContext.priv memory itself.
516 * This callback may be called even if @ref AVFilter.init "init" was not
517 * called or failed, so it must be prepared to handle such a situation.
519 void (*uninit)(AVFilterContext *ctx);
522 * Query formats supported by the filter on its inputs and outputs.
524 * This callback is called after the filter is initialized (so the inputs
525 * and outputs are fixed), shortly before the format negotiation. This
526 * callback may be called more than once.
528 * This callback must set AVFilterLink.out_formats on every input link and
529 * AVFilterLink.in_formats on every output link to a list of pixel/sample
530 * formats that the filter supports on that link. For audio links, this
531 * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" /
532 * @ref AVFilterLink.out_samplerates "out_samplerates" and
533 * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" /
534 * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously.
536 * This callback may be NULL for filters with one input, in which case
537 * libavfilter assumes that it supports all input formats and preserves
540 * @return zero on success, a negative value corresponding to an
541 * AVERROR code otherwise
543 int (*query_formats)(AVFilterContext *);
545 int priv_size; ///< size of private data to allocate for the filter
548 * Used by the filter registration system. Must not be touched by any other
551 struct AVFilter *next;
555 * Process multiple parts of the frame concurrently.
557 #define AVFILTER_THREAD_SLICE (1 << 0)
559 typedef struct AVFilterInternal AVFilterInternal;
561 /** An instance of a filter */
562 struct AVFilterContext {
563 const AVClass *av_class; ///< needed for av_log()
565 const AVFilter *filter; ///< the AVFilter of which this is an instance
567 char *name; ///< name of this filter instance
569 AVFilterPad *input_pads; ///< array of input pads
570 AVFilterLink **inputs; ///< array of pointers to input links
572 attribute_deprecated unsigned input_count; ///< @deprecated use nb_inputs
574 unsigned nb_inputs; ///< number of input pads
576 AVFilterPad *output_pads; ///< array of output pads
577 AVFilterLink **outputs; ///< array of pointers to output links
579 attribute_deprecated unsigned output_count; ///< @deprecated use nb_outputs
581 unsigned nb_outputs; ///< number of output pads
583 void *priv; ///< private data for use by the filter
585 struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
588 * Type of multithreading being allowed/used. A combination of
589 * AVFILTER_THREAD_* flags.
591 * May be set by the caller before initializing the filter to forbid some
592 * or all kinds of multithreading for this filter. The default is allowing
595 * When the filter is initialized, this field is combined using bit AND with
596 * AVFilterGraph.thread_type to get the final mask used for determining
597 * allowed threading types. I.e. a threading type needs to be set in both
600 * After the filter is initialzed, libavfilter sets this field to the
601 * threading type that is actually used (0 for no multithreading).
606 * An opaque struct for libavfilter internal use.
608 AVFilterInternal *internal;
612 * A link between two filters. This contains pointers to the source and
613 * destination filters between which this link exists, and the indexes of
614 * the pads involved. In addition, this link also contains the parameters
615 * which have been negotiated and agreed upon between the filter, such as
616 * image dimensions, format, etc.
618 struct AVFilterLink {
619 AVFilterContext *src; ///< source filter
620 AVFilterPad *srcpad; ///< output pad on the source filter
622 AVFilterContext *dst; ///< dest filter
623 AVFilterPad *dstpad; ///< input pad on the dest filter
625 enum AVMediaType type; ///< filter media type
627 /* These parameters apply only to video */
628 int w; ///< agreed upon image width
629 int h; ///< agreed upon image height
630 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
631 /* These two parameters apply only to audio */
632 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
633 int sample_rate; ///< samples per second
635 int format; ///< agreed upon media format
638 * Define the time base used by the PTS of the frames/samples
639 * which will pass through this link.
640 * During the configuration stage, each filter is supposed to
641 * change only the output timebase, while the timebase of the
642 * input link is assumed to be an unchangeable property.
644 AVRational time_base;
646 /*****************************************************************
647 * All fields below this line are not part of the public API. They
648 * may not be used outside of libavfilter and can be changed and
650 * New public fields should be added right above.
651 *****************************************************************
654 * Lists of formats supported by the input and output filters respectively.
655 * These lists are used for negotiating the format to actually be used,
656 * which will be loaded into the format member, above, when chosen.
658 AVFilterFormats *in_formats;
659 AVFilterFormats *out_formats;
662 * Lists of channel layouts and sample rates used for automatic
665 AVFilterFormats *in_samplerates;
666 AVFilterFormats *out_samplerates;
667 struct AVFilterChannelLayouts *in_channel_layouts;
668 struct AVFilterChannelLayouts *out_channel_layouts;
671 * Audio only, the destination filter sets this to a non-zero value to
672 * request that buffers with the given number of samples should be sent to
673 * it. AVFilterPad.needs_fifo must also be set on the corresponding input
675 * Last buffer before EOF will be padded with silence.
679 /** stage of the initialization of the link properties (dimensions, etc) */
681 AVLINK_UNINIT = 0, ///< not started
682 AVLINK_STARTINIT, ///< started, but incomplete
683 AVLINK_INIT ///< complete
688 * Link two filters together.
690 * @param src the source filter
691 * @param srcpad index of the output pad on the source filter
692 * @param dst the destination filter
693 * @param dstpad index of the input pad on the destination filter
694 * @return zero on success
696 int avfilter_link(AVFilterContext *src, unsigned srcpad,
697 AVFilterContext *dst, unsigned dstpad);
700 * Negotiate the media format, dimensions, etc of all inputs to a filter.
702 * @param filter the filter to negotiate the properties for its inputs
703 * @return zero on successful negotiation
705 int avfilter_config_links(AVFilterContext *filter);
707 #if FF_API_AVFILTERBUFFER
709 * Create a buffer reference wrapped around an already allocated image
712 * @param data pointers to the planes of the image to reference
713 * @param linesize linesizes for the planes of the image to reference
714 * @param perms the required access permissions
715 * @param w the width of the image specified by the data and linesize arrays
716 * @param h the height of the image specified by the data and linesize arrays
717 * @param format the pixel format of the image specified by the data and linesize arrays
721 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
722 int w, int h, enum AVPixelFormat format);
725 * Create an audio buffer reference wrapped around an already
726 * allocated samples buffer.
728 * @param data pointers to the samples plane buffers
729 * @param linesize linesize for the samples plane buffers
730 * @param perms the required access permissions
731 * @param nb_samples number of samples per channel
732 * @param sample_fmt the format of each sample in the buffer to allocate
733 * @param channel_layout the channel layout of the buffer
736 AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays(uint8_t **data,
740 enum AVSampleFormat sample_fmt,
741 uint64_t channel_layout);
744 /** Initialize the filter system. Register all builtin filters. */
745 void avfilter_register_all(void);
747 #if FF_API_OLD_FILTER_REGISTER
748 /** Uninitialize the filter system. Unregister all filters. */
750 void avfilter_uninit(void);
754 * Register a filter. This is only needed if you plan to use
755 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
756 * filter can still by instantiated with avfilter_graph_alloc_filter even if it
759 * @param filter the filter to register
760 * @return 0 if the registration was succesfull, a negative value
763 int avfilter_register(AVFilter *filter);
766 * Get a filter definition matching the given name.
768 * @param name the filter name to find
769 * @return the filter definition, if any matching one is registered.
770 * NULL if none found.
772 #if !FF_API_NOCONST_GET_NAME
775 AVFilter *avfilter_get_by_name(const char *name);
778 * Iterate over all registered filters.
779 * @return If prev is non-NULL, next registered filter after prev or NULL if
780 * prev is the last filter. If prev is NULL, return the first registered filter.
782 const AVFilter *avfilter_next(const AVFilter *prev);
784 #if FF_API_OLD_FILTER_REGISTER
786 * If filter is NULL, returns a pointer to the first registered filter pointer,
787 * if filter is non-NULL, returns the next pointer after filter.
788 * If the returned pointer points to NULL, the last registered filter
789 * was already reached.
790 * @deprecated use avfilter_next()
793 AVFilter **av_filter_next(AVFilter **filter);
796 #if FF_API_AVFILTER_OPEN
798 * Create a filter instance.
800 * @param filter_ctx put here a pointer to the created filter context
801 * on success, NULL on failure
802 * @param filter the filter to create an instance of
803 * @param inst_name Name to give to the new instance. Can be NULL for none.
804 * @return >= 0 in case of success, a negative error code otherwise
805 * @deprecated use avfilter_graph_alloc_filter() instead
808 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
812 #if FF_API_AVFILTER_INIT_FILTER
814 * Initialize a filter.
816 * @param filter the filter to initialize
817 * @param args A string of parameters to use when initializing the filter.
818 * The format and meaning of this string varies by filter.
819 * @param opaque Any extra non-string data needed by the filter. The meaning
820 * of this parameter varies by filter.
821 * @return zero on success
824 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
828 * Initialize a filter with the supplied parameters.
830 * @param ctx uninitialized filter context to initialize
831 * @param args Options to initialize the filter with. This must be a
832 * ':'-separated list of options in the 'key=value' form.
833 * May be NULL if the options have been set directly using the
834 * AVOptions API or there are no options that need to be set.
835 * @return 0 on success, a negative AVERROR on failure
837 int avfilter_init_str(AVFilterContext *ctx, const char *args);
840 * Initialize a filter with the supplied dictionary of options.
842 * @param ctx uninitialized filter context to initialize
843 * @param options An AVDictionary filled with options for this filter. On
844 * return this parameter will be destroyed and replaced with
845 * a dict containing options that were not found. This dictionary
846 * must be freed by the caller.
847 * May be NULL, then this function is equivalent to
848 * avfilter_init_str() with the second parameter set to NULL.
849 * @return 0 on success, a negative AVERROR on failure
851 * @note This function and avfilter_init_str() do essentially the same thing,
852 * the difference is in manner in which the options are passed. It is up to the
853 * calling code to choose whichever is more preferable. The two functions also
854 * behave differently when some of the provided options are not declared as
855 * supported by the filter. In such a case, avfilter_init_str() will fail, but
856 * this function will leave those extra options in the options AVDictionary and
859 int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options);
862 * Free a filter context. This will also remove the filter from its
863 * filtergraph's list of filters.
865 * @param filter the filter to free
867 void avfilter_free(AVFilterContext *filter);
870 * Insert a filter in the middle of an existing link.
872 * @param link the link into which the filter should be inserted
873 * @param filt the filter to be inserted
874 * @param filt_srcpad_idx the input pad on the filter to connect
875 * @param filt_dstpad_idx the output pad on the filter to connect
876 * @return zero on success
878 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
879 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
881 #if FF_API_AVFILTERBUFFER
883 * Copy the frame properties of src to dst, without copying the actual
886 * @return 0 on success, a negative number on error.
889 int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src);
892 * Copy the frame properties and data pointers of src to dst, without copying
895 * @return 0 on success, a negative number on error.
898 int avfilter_copy_buf_props(AVFrame *dst, const AVFilterBufferRef *src);
902 * @return AVClass for AVFilterContext.
904 * @see av_opt_find().
906 const AVClass *avfilter_get_class(void);
908 typedef struct AVFilterGraphInternal AVFilterGraphInternal;
911 * A function pointer passed to the @ref AVFilterGraph.execute callback to be
912 * executed multiple times, possibly in parallel.
914 * @param ctx the filter context the job belongs to
915 * @param arg an opaque parameter passed through from @ref
916 * AVFilterGraph.execute
917 * @param jobnr the index of the job being executed
918 * @param nb_jobs the total number of jobs
920 * @return 0 on success, a negative AVERROR on error
922 typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
925 * A function executing multiple jobs, possibly in parallel.
927 * @param ctx the filter context to which the jobs belong
928 * @param func the function to be called multiple times
929 * @param arg the argument to be passed to func
930 * @param ret a nb_jobs-sized array to be filled with return values from each
932 * @param nb_jobs the number of jobs to execute
934 * @return 0 on success, a negative AVERROR on error
936 typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
937 void *arg, int *ret, int nb_jobs);
939 typedef struct AVFilterGraph {
940 const AVClass *av_class;
943 unsigned filter_count;
945 AVFilterContext **filters;
946 #if !FF_API_FOO_COUNT
950 char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
951 char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
957 * Type of multithreading allowed for filters in this graph. A combination
958 * of AVFILTER_THREAD_* flags.
960 * May be set by the caller at any point, the setting will apply to all
961 * filters initialized after that. The default is allowing everything.
963 * When a filter in this graph is initialized, this field is combined using
964 * bit AND with AVFilterContext.thread_type to get the final mask used for
965 * determining allowed threading types. I.e. a threading type needs to be
966 * set in both to be allowed.
971 * Maximum number of threads used by filters in this graph. May be set by
972 * the caller before adding any filters to the filtergraph. Zero (the
973 * default) means that the number of threads is determined automatically.
978 * Opaque object for libavfilter internal use.
980 AVFilterGraphInternal *internal;
983 * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
984 * be used from callbacks like @ref AVFilterGraph.execute.
985 * Libavfilter will not touch this field in any way.
990 * This callback may be set by the caller immediately after allocating the
991 * graph and before adding any filters to it, to provide a custom
992 * multithreading implementation.
994 * If set, filters with slice threading capability will call this callback
995 * to execute multiple jobs in parallel.
997 * If this field is left unset, libavfilter will use its internal
998 * implementation, which may or may not be multithreaded depending on the
999 * platform and build options.
1001 avfilter_execute_func *execute;
1005 * Allocate a filter graph.
1007 * @return the allocated filter graph on success or NULL.
1009 AVFilterGraph *avfilter_graph_alloc(void);
1012 * Create a new filter instance in a filter graph.
1014 * @param graph graph in which the new filter will be used
1015 * @param filter the filter to create an instance of
1016 * @param name Name to give to the new instance (will be copied to
1017 * AVFilterContext.name). This may be used by the caller to identify
1018 * different filters, libavfilter itself assigns no semantics to
1019 * this parameter. May be NULL.
1021 * @return the context of the newly created filter instance (note that it is
1022 * also retrievable directly through AVFilterGraph.filters or with
1023 * avfilter_graph_get_filter()) on success or NULL or failure.
1025 AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
1026 const AVFilter *filter,
1030 * Get a filter instance with name name from graph.
1032 * @return the pointer to the found filter instance or NULL if it
1035 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name);
1037 #if FF_API_AVFILTER_OPEN
1039 * Add an existing filter instance to a filter graph.
1041 * @param graphctx the filter graph
1042 * @param filter the filter to be added
1044 * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a
1047 attribute_deprecated
1048 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
1052 * Create and add a filter instance into an existing graph.
1053 * The filter instance is created from the filter filt and inited
1054 * with the parameters args and opaque.
1056 * In case of success put in *filt_ctx the pointer to the created
1057 * filter instance, otherwise set *filt_ctx to NULL.
1059 * @param name the instance name to give to the created filter instance
1060 * @param graph_ctx the filter graph
1061 * @return a negative AVERROR error code in case of failure, a non
1062 * negative value otherwise
1064 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
1065 const char *name, const char *args, void *opaque,
1066 AVFilterGraph *graph_ctx);
1069 * Check validity and configure all the links and formats in the graph.
1071 * @param graphctx the filter graph
1072 * @param log_ctx context used for logging
1073 * @return 0 in case of success, a negative AVERROR code otherwise
1075 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
1078 * Free a graph, destroy its links, and set *graph to NULL.
1079 * If *graph is NULL, do nothing.
1081 void avfilter_graph_free(AVFilterGraph **graph);
1084 * A linked-list of the inputs/outputs of the filter chain.
1086 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
1087 * where it is used to communicate open (unlinked) inputs and outputs from and
1089 * This struct specifies, per each not connected pad contained in the graph, the
1090 * filter context and the pad index required for establishing a link.
1092 typedef struct AVFilterInOut {
1093 /** unique name for this input/output in the list */
1096 /** filter context associated to this input/output */
1097 AVFilterContext *filter_ctx;
1099 /** index of the filt_ctx pad to use for linking */
1102 /** next input/input in the list, NULL if this is the last */
1103 struct AVFilterInOut *next;
1107 * Allocate a single AVFilterInOut entry.
1108 * Must be freed with avfilter_inout_free().
1109 * @return allocated AVFilterInOut on success, NULL on failure.
1111 AVFilterInOut *avfilter_inout_alloc(void);
1114 * Free the supplied list of AVFilterInOut and set *inout to NULL.
1115 * If *inout is NULL, do nothing.
1117 void avfilter_inout_free(AVFilterInOut **inout);
1120 * Add a graph described by a string to a graph.
1122 * @param graph the filter graph where to link the parsed graph context
1123 * @param filters string to be parsed
1124 * @param inputs linked list to the inputs of the graph
1125 * @param outputs linked list to the outputs of the graph
1126 * @return zero on success, a negative AVERROR code on error
1128 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
1129 AVFilterInOut *inputs, AVFilterInOut *outputs,
1133 * Add a graph described by a string to a graph.
1135 * @param[in] graph the filter graph where to link the parsed graph context
1136 * @param[in] filters string to be parsed
1137 * @param[out] inputs a linked list of all free (unlinked) inputs of the
1138 * parsed graph will be returned here. It is to be freed
1139 * by the caller using avfilter_inout_free().
1140 * @param[out] outputs a linked list of all free (unlinked) outputs of the
1141 * parsed graph will be returned here. It is to be freed by the
1142 * caller using avfilter_inout_free().
1143 * @return zero on success, a negative AVERROR code on error
1145 * @note the difference between avfilter_graph_parse2() and
1146 * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
1147 * the lists of inputs and outputs, which therefore must be known before calling
1148 * the function. On the other hand, avfilter_graph_parse2() \em returns the
1149 * inputs and outputs that are left unlinked after parsing the graph and the
1150 * caller then deals with them. Another difference is that in
1151 * avfilter_graph_parse(), the inputs parameter describes inputs of the
1152 * <em>already existing</em> part of the graph; i.e. from the point of view of
1153 * the newly created part, they are outputs. Similarly the outputs parameter
1154 * describes outputs of the already existing filters, which are provided as
1155 * inputs to the parsed filters.
1156 * avfilter_graph_parse2() takes the opposite approach -- it makes no reference
1157 * whatsoever to already existing parts of the graph and the inputs parameter
1158 * will on return contain inputs of the newly parsed part of the graph.
1159 * Analogously the outputs parameter will contain outputs of the newly created
1162 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
1163 AVFilterInOut **inputs,
1164 AVFilterInOut **outputs);
1170 #endif /* AVFILTER_AVFILTER_H */