3 * Copyright (c) 2007 Bobby Bingham
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #ifndef AVFILTER_AVFILTER_H
23 #define AVFILTER_AVFILTER_H
32 * @defgroup lavfi Libavfilter
38 #include "libavutil/avutil.h"
39 #include "libavutil/dict.h"
40 #include "libavutil/log.h"
41 #include "libavutil/samplefmt.h"
42 #include "libavutil/pixfmt.h"
43 #include "libavutil/rational.h"
45 #include "libavfilter/version.h"
48 * Return the LIBAVFILTER_VERSION_INT constant.
50 unsigned avfilter_version(void);
53 * Return the libavfilter build-time configuration.
55 const char *avfilter_configuration(void);
58 * Return the libavfilter license.
60 const char *avfilter_license(void);
63 * Get the class for the AVFilterContext struct.
65 const AVClass *avfilter_get_class(void);
67 typedef struct AVFilterContext AVFilterContext;
68 typedef struct AVFilterLink AVFilterLink;
69 typedef struct AVFilterPad AVFilterPad;
70 typedef struct AVFilterFormats AVFilterFormats;
73 * A reference-counted buffer data type used by the filter system. Filters
74 * should not store pointers to this structure directly, but instead use the
75 * AVFilterBufferRef structure below.
77 typedef struct AVFilterBuffer {
78 uint8_t *data[8]; ///< buffer data for each plane/channel
81 * pointers to the data planes/channels.
83 * For video, this should simply point to data[].
85 * For planar audio, each channel has a separate data pointer, and
86 * linesize[0] contains the size of each channel buffer.
87 * For packed audio, there is just one data pointer, and linesize[0]
88 * contains the total size of the buffer for all channels.
90 * Note: Both data and extended_data will always be set, but for planar
91 * audio with more channels that can fit in data, extended_data must be used
92 * in order to access all channels.
94 uint8_t **extended_data;
95 int linesize[8]; ///< number of bytes per line
97 /** private data to be used by a custom free function */
100 * A pointer to the function to deallocate this buffer if the default
101 * function is not sufficient. This could, for example, add the memory
102 * back into a memory pool to be reused later without the overhead of
103 * reallocating it from scratch.
105 void (*free)(struct AVFilterBuffer *buf);
107 int format; ///< media format
108 int w, h; ///< width and height of the allocated buffer
109 unsigned refcount; ///< number of references to this buffer
112 #define AV_PERM_READ 0x01 ///< can read from the buffer
113 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
114 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
115 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
116 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
117 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
118 #define AV_PERM_ALIGN 0x40 ///< the buffer must be aligned
120 #define AVFILTER_ALIGN 16 //not part of ABI
123 * Audio specific properties in a reference to an AVFilterBuffer. Since
124 * AVFilterBufferRef is common to different media formats, audio specific
125 * per reference properties must be separated out.
127 typedef struct AVFilterBufferRefAudioProps {
128 uint64_t channel_layout; ///< channel layout of audio buffer
129 int nb_samples; ///< number of audio samples per channel
130 int sample_rate; ///< audio buffer sample rate
131 int channels; ///< number of channels
132 } AVFilterBufferRefAudioProps;
135 * Video specific properties in a reference to an AVFilterBuffer. Since
136 * AVFilterBufferRef is common to different media formats, video specific
137 * per reference properties must be separated out.
139 typedef struct AVFilterBufferRefVideoProps {
140 int w; ///< image width
141 int h; ///< image height
142 AVRational sample_aspect_ratio; ///< sample aspect ratio
143 int interlaced; ///< is frame interlaced
144 int top_field_first; ///< field order
145 enum AVPictureType pict_type; ///< picture type of the frame
146 int key_frame; ///< 1 -> keyframe, 0-> not
147 int qp_table_linesize; ///< qp_table stride
148 int qp_table_size; ///< qp_table size
149 int8_t *qp_table; ///< array of Quantization Parameters
150 } AVFilterBufferRefVideoProps;
153 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
154 * a buffer to, for example, crop image without any memcpy, the buffer origin
155 * and dimensions are per-reference properties. Linesize is also useful for
156 * image flipping, frame to field filters, etc, and so is also per-reference.
158 * TODO: add anything necessary for frame reordering
160 typedef struct AVFilterBufferRef {
161 AVFilterBuffer *buf; ///< the buffer that this is a reference to
162 uint8_t *data[8]; ///< picture/audio data for each plane
164 * pointers to the data planes/channels.
166 * For video, this should simply point to data[].
168 * For planar audio, each channel has a separate data pointer, and
169 * linesize[0] contains the size of each channel buffer.
170 * For packed audio, there is just one data pointer, and linesize[0]
171 * contains the total size of the buffer for all channels.
173 * Note: Both data and extended_data will always be set, but for planar
174 * audio with more channels that can fit in data, extended_data must be used
175 * in order to access all channels.
177 uint8_t **extended_data;
178 int linesize[8]; ///< number of bytes per line
180 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
181 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
184 * presentation timestamp. The time unit may change during
185 * filtering, as it is specified in the link and the filter code
186 * may need to rescale the PTS accordingly.
189 int64_t pos; ///< byte position in stream, -1 if unknown
191 int format; ///< media format
193 int perms; ///< permissions, see the AV_PERM_* flags
195 enum AVMediaType type; ///< media type of buffer data
197 AVDictionary *metadata; ///< dictionary containing metadata key=value tags
201 * Copy properties of src to dst, without copying the actual data
203 void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src);
206 * Add a new reference to a buffer.
208 * @param ref an existing reference to the buffer
209 * @param pmask a bitmask containing the allowable permissions in the new
211 * @return a new reference to the buffer with the same properties as the
212 * old, excluding any permissions denied by pmask
214 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
217 * Remove a reference to a buffer. If this is the last reference to the
218 * buffer, the buffer itself is also automatically freed.
220 * @param ref reference to the buffer, may be NULL
222 * @note it is recommended to use avfilter_unref_bufferp() instead of this
225 void avfilter_unref_buffer(AVFilterBufferRef *ref);
228 * Remove a reference to a buffer and set the pointer to NULL.
229 * If this is the last reference to the buffer, the buffer itself
230 * is also automatically freed.
232 * @param ref pointer to the buffer reference
234 void avfilter_unref_bufferp(AVFilterBufferRef **ref);
236 #if FF_API_AVFILTERPAD_PUBLIC
238 * A filter pad used for either input or output.
240 * See doc/filter_design.txt for details on how to implement the methods.
242 * @warning this struct might be removed from public API.
243 * users should call avfilter_pad_get_name() and avfilter_pad_get_type()
244 * to access the name and type fields; there should be no need to access
245 * any other fields from outside of libavfilter.
249 * Pad name. The name is unique among inputs and among outputs, but an
250 * input may have the same name as an output. This may be NULL if this
251 * pad has no need to ever be referenced by name.
258 enum AVMediaType type;
262 * Minimum required permissions on incoming buffers. Any buffer with
263 * insufficient permissions will be automatically copied by the filter
264 * system to a new buffer which provides the needed access permissions.
267 * Guaranteed permissions on outgoing buffers. Any buffer pushed on the
268 * link must have at least these permissions; this fact is checked by
269 * asserts. It can be used to optimize buffer allocation.
275 * Permissions which are not accepted on incoming buffers. Any buffer
276 * which has any of these permissions set will be automatically copied
277 * by the filter system to a new buffer which does not have those
278 * permissions. This can be used to easily disallow buffers with
282 * Permissions which are automatically removed on outgoing buffers. It
283 * can be used to optimize buffer allocation.
290 int (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
293 * Callback function to get a video buffer. If NULL, the filter system will
294 * use ff_default_get_video_buffer().
296 * Input video pads only.
298 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
301 * Callback function to get an audio buffer. If NULL, the filter system will
302 * use ff_default_get_audio_buffer().
304 * Input audio pads only.
306 AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms,
312 int (*end_frame)(AVFilterLink *link);
317 int (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
320 * Filtering callback. This is where a filter receives a frame with
321 * audio/video data and should do its processing.
325 * @return >= 0 on success, a negative AVERROR on error. This function
326 * must ensure that frame is properly unreferenced on error if it
327 * hasn't been passed on to another filter.
329 int (*filter_frame)(AVFilterLink *link, AVFilterBufferRef *frame);
332 * Frame poll callback. This returns the number of immediately available
333 * samples. It should return a positive value if the next request_frame()
334 * is guaranteed to return one frame (with no delay).
336 * Defaults to just calling the source poll_frame() method.
340 int (*poll_frame)(AVFilterLink *link);
343 * Frame request callback. A call to this should result in at least one
344 * frame being output over the given link. This should return zero on
345 * success, and another value on error.
346 * See ff_request_frame() for the error codes with a specific
351 int (*request_frame)(AVFilterLink *link);
354 * Link configuration callback.
356 * For output pads, this should set the following link properties:
357 * video: width, height, sample_aspect_ratio, time_base
358 * audio: sample_rate.
360 * This should NOT set properties such as format, channel_layout, etc which
361 * are negotiated between filters by the filter system using the
362 * query_formats() callback before this function is called.
364 * For input pads, this should check the properties of the link, and update
365 * the filter's internal state as necessary.
367 * For both input and output pads, this should return zero on success,
368 * and another value on error.
370 int (*config_props)(AVFilterLink *link);
373 * The filter expects a fifo to be inserted on its input link,
374 * typically because it has a delay.
383 * Get the name of an AVFilterPad.
385 * @param pads an array of AVFilterPads
386 * @param pad_idx index of the pad in the array it; is the caller's
387 * responsibility to ensure the index is valid
389 * @return name of the pad_idx'th pad in pads
391 const char *avfilter_pad_get_name(AVFilterPad *pads, int pad_idx);
394 * Get the type of an AVFilterPad.
396 * @param pads an array of AVFilterPads
397 * @param pad_idx index of the pad in the array; it is the caller's
398 * responsibility to ensure the index is valid
400 * @return type of the pad_idx'th pad in pads
402 enum AVMediaType avfilter_pad_get_type(AVFilterPad *pads, int pad_idx);
405 * Filter definition. This defines the pads a filter contains, and all the
406 * callback functions used to interact with the filter.
408 typedef struct AVFilter {
409 const char *name; ///< filter name
412 * A description for the filter. You should use the
413 * NULL_IF_CONFIG_SMALL() macro to define it.
415 const char *description;
417 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
418 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
420 /*****************************************************************
421 * All fields below this line are not part of the public API. They
422 * may not be used outside of libavfilter and can be changed and
424 * New public fields should be added right above.
425 *****************************************************************
429 * Filter initialization function. Args contains the user-supplied
430 * parameters. FIXME: maybe an AVOption-based system would be better?
432 int (*init)(AVFilterContext *ctx, const char *args);
435 * Filter uninitialization function. Should deallocate any memory held
436 * by the filter, release any buffer references, etc. This does not need
437 * to deallocate the AVFilterContext->priv memory itself.
439 void (*uninit)(AVFilterContext *ctx);
442 * Queries formats/layouts supported by the filter and its pads, and sets
443 * the in_formats/in_chlayouts for links connected to its output pads,
444 * and out_formats/out_chlayouts for links connected to its input pads.
446 * @return zero on success, a negative value corresponding to an
447 * AVERROR code otherwise
449 int (*query_formats)(AVFilterContext *);
451 int priv_size; ///< size of private data to allocate for the filter
454 * Make the filter instance process a command.
456 * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
457 * @param arg the argument for the command
458 * @param res a buffer with size res_size where the filter(s) can return a response. This must not change when the command is not supported.
459 * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
460 * time consuming then a filter should treat it like an unsupported command
462 * @returns >=0 on success otherwise an error code.
463 * AVERROR(ENOSYS) on unsupported commands
465 int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
468 * Filter initialization function, alternative to the init()
469 * callback. Args contains the user-supplied parameters, opaque is
470 * used for providing binary data.
472 int (*init_opaque)(AVFilterContext *ctx, const char *args, void *opaque);
474 const AVClass *priv_class; ///< private class, containing filter specific options
477 /** An instance of a filter */
478 struct AVFilterContext {
479 const AVClass *av_class; ///< needed for av_log()
481 AVFilter *filter; ///< the AVFilter of which this is an instance
483 char *name; ///< name of this filter instance
485 AVFilterPad *input_pads; ///< array of input pads
486 AVFilterLink **inputs; ///< array of pointers to input links
488 unsigned input_count; ///< @deprecated use nb_inputs
490 unsigned nb_inputs; ///< number of input pads
492 AVFilterPad *output_pads; ///< array of output pads
493 AVFilterLink **outputs; ///< array of pointers to output links
495 unsigned output_count; ///< @deprecated use nb_outputs
497 unsigned nb_outputs; ///< number of output pads
499 void *priv; ///< private data for use by the filter
501 struct AVFilterCommand *command_queue;
505 * A link between two filters. This contains pointers to the source and
506 * destination filters between which this link exists, and the indexes of
507 * the pads involved. In addition, this link also contains the parameters
508 * which have been negotiated and agreed upon between the filter, such as
509 * image dimensions, format, etc.
511 struct AVFilterLink {
512 AVFilterContext *src; ///< source filter
513 AVFilterPad *srcpad; ///< output pad on the source filter
515 AVFilterContext *dst; ///< dest filter
516 AVFilterPad *dstpad; ///< input pad on the dest filter
518 enum AVMediaType type; ///< filter media type
520 /* These parameters apply only to video */
521 int w; ///< agreed upon image width
522 int h; ///< agreed upon image height
523 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
524 /* These parameters apply only to audio */
525 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
526 int sample_rate; ///< samples per second
528 int format; ///< agreed upon media format
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 formats and channel layouts supported by the input and output
548 * filters respectively. These lists are used for negotiating the format
549 * to actually be used, which will be loaded into the format and
550 * channel_layout members, above, when chosen.
553 AVFilterFormats *in_formats;
554 AVFilterFormats *out_formats;
557 * Lists of channel layouts and sample rates used for automatic
560 AVFilterFormats *in_samplerates;
561 AVFilterFormats *out_samplerates;
562 struct AVFilterChannelLayouts *in_channel_layouts;
563 struct AVFilterChannelLayouts *out_channel_layouts;
566 * Audio only, the destination filter sets this to a non-zero value to
567 * request that buffers with the given number of samples should be sent to
568 * it. AVFilterPad.needs_fifo must also be set on the corresponding input
570 * Last buffer before EOF will be padded with silence.
574 /** stage of the initialization of the link properties (dimensions, etc) */
576 AVLINK_UNINIT = 0, ///< not started
577 AVLINK_STARTINIT, ///< started, but incomplete
578 AVLINK_INIT ///< complete
582 * The buffer reference currently being sent across the link by the source
583 * filter. This is used internally by the filter system to allow
584 * automatic copying of buffers which do not have sufficient permissions
585 * for the destination. This should not be accessed directly by the
588 AVFilterBufferRef *src_buf;
591 * The buffer reference to the frame sent across the link by the
592 * source filter, which is read by the destination filter. It is
593 * automatically set up by ff_start_frame().
595 * Depending on the permissions, it may either be the same as
596 * src_buf or an automatic copy of it.
598 * It is automatically freed by the filter system when calling
599 * ff_end_frame(). In case you save the buffer reference
600 * internally (e.g. if you cache it for later reuse), or give it
601 * away (e.g. if you pass the reference to the next filter) it
602 * must be set to NULL before calling ff_end_frame().
604 AVFilterBufferRef *cur_buf;
607 * The buffer reference to the frame which is sent to output by
610 * If no start_frame callback is defined on a link,
611 * ff_start_frame() will automatically request a new buffer on the
612 * first output link of the destination filter. The reference to
613 * the buffer so obtained is stored in the out_buf field on the
616 * It can also be set by the filter code in case the filter needs
617 * to access the output buffer later. For example the filter code
618 * may set it in a custom start_frame, and access it in
621 * It is automatically freed by the filter system in
624 AVFilterBufferRef *out_buf;
626 struct AVFilterPool *pool;
629 * Graph the filter belongs to.
631 struct AVFilterGraph *graph;
634 * Current timestamp of the link, as defined by the most recent
635 * frame(s), in AV_TIME_BASE units.
640 * Index in the age array.
645 * Frame rate of the stream on the link, or 1/0 if unknown;
646 * if left to 0/0, will be automatically be copied from the first input
647 * of the source filter if it exists.
649 * Sources should set it to the best estimation of the real frame rate.
650 * Filters should update it if necessary depending on their function.
651 * Sinks can use it to set a default output frame rate.
652 * It is similar to the r_frame_rate field in AVStream.
654 AVRational frame_rate;
657 * Buffer partially filled with samples to achieve a fixed/minimum size.
659 AVFilterBufferRef *partial_buf;
662 * Size of the partial buffer to allocate.
663 * Must be between min_samples and max_samples.
665 int partial_buf_size;
668 * Minimum number of samples to filter at once. If filter_frame() is
669 * called with fewer samples, it will accumulate them in partial_buf.
670 * This field and the related ones must not be changed after filtering
672 * If 0, all related fields are ignored.
677 * Maximum number of samples to filter at once. If filter_frame() is
678 * called with more samples, it will split them.
683 * The buffer reference currently being received across the link by the
684 * destination filter. This is used internally by the filter system to
685 * allow automatic copying of buffers which do not have sufficient
686 * permissions for the destination. This should not be accessed directly
689 AVFilterBufferRef *cur_buf_copy;
692 * True if the link is closed.
693 * If set, all attemps of start_frame, filter_frame or request_frame
694 * will fail with AVERROR_EOF, and if necessary the reference will be
696 * If request_frame returns AVERROR_EOF, this flag is set on the
697 * corresponding link.
698 * It can be set also be set by either the source or the destination
705 * Link two filters together.
707 * @param src the source filter
708 * @param srcpad index of the output pad on the source filter
709 * @param dst the destination filter
710 * @param dstpad index of the input pad on the destination filter
711 * @return zero on success
713 int avfilter_link(AVFilterContext *src, unsigned srcpad,
714 AVFilterContext *dst, unsigned dstpad);
717 * Free the link in *link, and set its pointer to NULL.
719 void avfilter_link_free(AVFilterLink **link);
722 * Set the closed field of a link.
724 void avfilter_link_set_closed(AVFilterLink *link, int closed);
727 * Negotiate the media format, dimensions, etc of all inputs to a filter.
729 * @param filter the filter to negotiate the properties for its inputs
730 * @return zero on successful negotiation
732 int avfilter_config_links(AVFilterContext *filter);
735 * Create a buffer reference wrapped around an already allocated image
738 * @param data pointers to the planes of the image to reference
739 * @param linesize linesizes for the planes of the image to reference
740 * @param perms the required access permissions
741 * @param w the width of the image specified by the data and linesize arrays
742 * @param h the height of the image specified by the data and linesize arrays
743 * @param format the pixel format of the image specified by the data and linesize arrays
746 avfilter_get_video_buffer_ref_from_arrays(uint8_t * const data[4], const int linesize[4], int perms,
747 int w, int h, enum AVPixelFormat format);
750 * Create an audio buffer reference wrapped around an already
751 * allocated samples buffer.
753 * @param data pointers to the samples plane buffers
754 * @param linesize linesize for the samples plane buffers
755 * @param perms the required access permissions
756 * @param nb_samples number of samples per channel
757 * @param sample_fmt the format of each sample in the buffer to allocate
758 * @param channel_layout the channel layout of the buffer
760 AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays(uint8_t **data,
764 enum AVSampleFormat sample_fmt,
765 uint64_t channel_layout);
768 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
769 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
772 * Make the filter instance process a command.
773 * It is recommended to use avfilter_graph_send_command().
775 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
777 /** Initialize the filter system. Register all builtin filters. */
778 void avfilter_register_all(void);
780 /** Uninitialize the filter system. Unregister all filters. */
781 void avfilter_uninit(void);
784 * Register a filter. This is only needed if you plan to use
785 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
786 * filter can still by instantiated with avfilter_open even if it is not
789 * @param filter the filter to register
790 * @return 0 if the registration was successful, a negative value
793 int avfilter_register(AVFilter *filter);
796 * Get a filter definition matching the given name.
798 * @param name the filter name to find
799 * @return the filter definition, if any matching one is registered.
800 * NULL if none found.
802 AVFilter *avfilter_get_by_name(const char *name);
805 * If filter is NULL, returns a pointer to the first registered filter pointer,
806 * if filter is non-NULL, returns the next pointer after filter.
807 * If the returned pointer points to NULL, the last registered filter
808 * was already reached.
810 AVFilter **av_filter_next(AVFilter **filter);
813 * Create a filter instance.
815 * @param filter_ctx put here a pointer to the created filter context
816 * on success, NULL on failure
817 * @param filter the filter to create an instance of
818 * @param inst_name Name to give to the new instance. Can be NULL for none.
819 * @return >= 0 in case of success, a negative error code otherwise
821 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
824 * Initialize a filter.
826 * @param filter the filter to initialize
827 * @param args A string of parameters to use when initializing the filter.
828 * The format and meaning of this string varies by filter.
829 * @param opaque Any extra non-string data needed by the filter. The meaning
830 * of this parameter varies by filter.
831 * @return zero on success
833 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
836 * Free a filter context.
838 * @param filter the filter to free
840 void avfilter_free(AVFilterContext *filter);
843 * Insert a filter in the middle of an existing link.
845 * @param link the link into which the filter should be inserted
846 * @param filt the filter to be inserted
847 * @param filt_srcpad_idx the input pad on the filter to connect
848 * @param filt_dstpad_idx the output pad on the filter to connect
849 * @return zero on success
851 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
852 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
858 #endif /* AVFILTER_AVFILTER_H */