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
25 #include "libavutil/avutil.h"
26 #include "libavutil/log.h"
27 #include "libavutil/samplefmt.h"
28 #include "libavutil/pixfmt.h"
29 #include "libavutil/rational.h"
30 #include "libavcodec/avcodec.h"
33 #ifndef FF_API_OLD_VSINK_API
34 #define FF_API_OLD_VSINK_API (LIBAVFILTER_VERSION_MAJOR < 3)
36 #ifndef FF_API_OLD_ALL_FORMATS_API
37 #define FF_API_OLD_ALL_FORMATS_API (LIBAVFILTER_VERSION_MAJOR < 3)
42 #include "libavfilter/version.h"
45 * Return the LIBAVFILTER_VERSION_INT constant.
47 unsigned avfilter_version(void);
50 * Return the libavfilter build-time configuration.
52 const char *avfilter_configuration(void);
55 * Return the libavfilter license.
57 const char *avfilter_license(void);
60 typedef struct AVFilterContext AVFilterContext;
61 typedef struct AVFilterLink AVFilterLink;
62 typedef struct AVFilterPad AVFilterPad;
65 * A reference-counted buffer data type used by the filter system. Filters
66 * should not store pointers to this structure directly, but instead use the
67 * AVFilterBufferRef structure below.
69 typedef struct AVFilterBuffer {
70 uint8_t *data[8]; ///< buffer data for each plane/channel
71 int linesize[8]; ///< number of bytes per line
73 unsigned refcount; ///< number of references to this buffer
75 /** private data to be used by a custom free function */
78 * A pointer to the function to deallocate this buffer if the default
79 * function is not sufficient. This could, for example, add the memory
80 * back into a memory pool to be reused later without the overhead of
81 * reallocating it from scratch.
83 void (*free)(struct AVFilterBuffer *buf);
85 int format; ///< media format
86 int w, h; ///< width and height of the allocated buffer
89 #define AV_PERM_READ 0x01 ///< can read from the buffer
90 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
91 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
92 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
93 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
94 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
95 #define AV_PERM_ALIGN 0x40 ///< the buffer must be aligned
97 #define AVFILTER_ALIGN 16 //not part of ABI
100 * Audio specific properties in a reference to an AVFilterBuffer. Since
101 * AVFilterBufferRef is common to different media formats, audio specific
102 * per reference properties must be separated out.
104 typedef struct AVFilterBufferRefAudioProps {
105 uint64_t channel_layout; ///< channel layout of audio buffer
106 int nb_samples; ///< number of audio samples per channel
107 int sample_rate; ///< audio buffer sample rate
108 int planar; ///< audio buffer - planar or packed
109 } AVFilterBufferRefAudioProps;
112 * Video specific properties in a reference to an AVFilterBuffer. Since
113 * AVFilterBufferRef is common to different media formats, video specific
114 * per reference properties must be separated out.
116 typedef struct AVFilterBufferRefVideoProps {
117 int w; ///< image width
118 int h; ///< image height
119 AVRational sample_aspect_ratio; ///< sample aspect ratio
120 int interlaced; ///< is frame interlaced
121 int top_field_first; ///< field order
122 enum AVPictureType pict_type; ///< picture type of the frame
123 int key_frame; ///< 1 -> keyframe, 0-> not
124 } AVFilterBufferRefVideoProps;
127 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
128 * a buffer to, for example, crop image without any memcpy, the buffer origin
129 * and dimensions are per-reference properties. Linesize is also useful for
130 * image flipping, frame to field filters, etc, and so is also per-reference.
132 * TODO: add anything necessary for frame reordering
134 typedef struct AVFilterBufferRef {
135 AVFilterBuffer *buf; ///< the buffer that this is a reference to
136 uint8_t *data[8]; ///< picture/audio data for each plane
137 int linesize[8]; ///< number of bytes per line
138 int format; ///< media format
141 * presentation timestamp. The time unit may change during
142 * filtering, as it is specified in the link and the filter code
143 * may need to rescale the PTS accordingly.
146 int64_t pos; ///< byte position in stream, -1 if unknown
148 int perms; ///< permissions, see the AV_PERM_* flags
150 enum AVMediaType type; ///< media type of buffer data
151 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
152 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
156 * Copy properties of src to dst, without copying the actual data
158 static inline void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src)
160 // copy common properties
165 case AVMEDIA_TYPE_VIDEO: *dst->video = *src->video; break;
166 case AVMEDIA_TYPE_AUDIO: *dst->audio = *src->audio; break;
172 * Add a new reference to a buffer.
174 * @param ref an existing reference to the buffer
175 * @param pmask a bitmask containing the allowable permissions in the new
177 * @return a new reference to the buffer with the same properties as the
178 * old, excluding any permissions denied by pmask
180 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
183 * Remove a reference to a buffer. If this is the last reference to the
184 * buffer, the buffer itself is also automatically freed.
186 * @param ref reference to the buffer, may be NULL
188 void avfilter_unref_buffer(AVFilterBufferRef *ref);
191 * A list of supported formats for one end of a filter link. This is used
192 * during the format negotiation process to try to pick the best format to
193 * use to minimize the number of necessary conversions. Each filter gives a
194 * list of the formats supported by each input and output pad. The list
195 * given for each pad need not be distinct - they may be references to the
196 * same list of formats, as is often the case when a filter supports multiple
197 * formats, but will always output the same format as it is given in input.
199 * In this way, a list of possible input formats and a list of possible
200 * output formats are associated with each link. When a set of formats is
201 * negotiated over a link, the input and output lists are merged to form a
202 * new list containing only the common elements of each list. In the case
203 * that there were no common elements, a format conversion is necessary.
204 * Otherwise, the lists are merged, and all other links which reference
205 * either of the format lists involved in the merge are also affected.
207 * For example, consider the filter chain:
208 * filter (a) --> (b) filter (b) --> (c) filter
210 * where the letters in parenthesis indicate a list of formats supported on
211 * the input or output of the link. Suppose the lists are as follows:
216 * First, the first link's lists are merged, yielding:
217 * filter (a) --> (a) filter (a) --> (c) filter
219 * Notice that format list (b) now refers to the same list as filter list (a).
220 * Next, the lists for the second link are merged, yielding:
221 * filter (a) --> (a) filter (a) --> (a) filter
225 * Unfortunately, when the format lists at the two ends of a link are merged,
226 * we must ensure that all links which reference either pre-merge format list
227 * get updated as well. Therefore, we have the format list structure store a
228 * pointer to each of the pointers to itself.
230 typedef struct AVFilterFormats {
231 unsigned format_count; ///< number of formats
232 int64_t *formats; ///< list of media formats
234 unsigned refcount; ///< number of references to this list
235 struct AVFilterFormats ***refs; ///< references to this list
239 * Create a list of supported formats. This is intended for use in
240 * AVFilter->query_formats().
242 * @param fmts list of media formats, terminated by -1. If NULL an
243 * empty list is created.
244 * @return the format list, with no existing references
246 AVFilterFormats *avfilter_make_format_list(const int *fmts);
247 AVFilterFormats *avfilter_make_format64_list(const int64_t *fmts);
250 * Add fmt to the list of media formats contained in *avff.
251 * If *avff is NULL the function allocates the filter formats struct
252 * and puts its pointer in *avff.
254 * @return a non negative value in case of success, or a negative
255 * value corresponding to an AVERROR code in case of error
257 int avfilter_add_format(AVFilterFormats **avff, int64_t fmt);
259 #if FF_API_OLD_ALL_FORMATS_API
261 * @deprecated Use avfilter_make_all_formats() instead.
264 AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
268 * Return a list of all formats supported by FFmpeg for the given media type.
270 AVFilterFormats *avfilter_make_all_formats(enum AVMediaType type);
273 * A list of all channel layouts supported by libavfilter.
275 extern const int64_t avfilter_all_channel_layouts[];
278 * Return a list of all channel layouts supported by FFmpeg.
280 AVFilterFormats *avfilter_make_all_channel_layouts(void);
283 * Return a list of all audio packing formats.
285 AVFilterFormats *avfilter_make_all_packing_formats(void);
288 * Return a format list which contains the intersection of the formats of
289 * a and b. Also, all the references of a, all the references of b, and
290 * a and b themselves will be deallocated.
292 * If a and b do not share any common formats, neither is modified, and NULL
295 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
298 * Add *ref as a new reference to formats.
299 * That is the pointers will point like in the ASCII art below:
301 * |formats |<--------.
302 * | ____ | ____|___________________
304 * | |* * | | | | | | AVFilterLink
305 * | |* *--------->|*ref|
306 * | |____| | | |____|
307 * |________| |________________________
309 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
312 * If *ref is non-NULL, remove *ref as a reference to the format list
313 * it currently points to, deallocates that list if this was the last
314 * reference, and sets *ref to NULL.
317 * ________ ________ NULL
318 * |formats |<--------. |formats | ^
319 * | ____ | ____|________________ | ____ | ____|________________
320 * | |refs| | | __|_ | |refs| | | __|_
321 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
322 * | |* *--------->|*ref| | |* | | | |*ref|
323 * | |____| | | |____| | |____| | | |____|
324 * |________| |_____________________ |________| |_____________________
326 void avfilter_formats_unref(AVFilterFormats **ref);
332 * |formats |<---------. |formats |<---------.
333 * | ____ | ___|___ | ____ | ___|___
334 * | |refs| | | | | | |refs| | | | | NULL
335 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
336 * | |* * | | |_______| | |* * | | |_______| ___|___
337 * | |____| | | |____| | | | |
338 * |________| |________| |*oldref|
341 void avfilter_formats_changeref(AVFilterFormats **oldref,
342 AVFilterFormats **newref);
345 * A filter pad used for either input or output.
349 * Pad name. The name is unique among inputs and among outputs, but an
350 * input may have the same name as an output. This may be NULL if this
351 * pad has no need to ever be referenced by name.
356 * AVFilterPad type. Can be AVMEDIA_TYPE_VIDEO or AVMEDIA_TYPE_AUDIO.
358 enum AVMediaType type;
361 * Minimum required permissions on incoming buffers. Any buffer with
362 * insufficient permissions will be automatically copied by the filter
363 * system to a new buffer which provides the needed access permissions.
370 * Permissions which are not accepted on incoming buffers. Any buffer
371 * which has any of these permissions set will be automatically copied
372 * by the filter system to a new buffer which does not have those
373 * permissions. This can be used to easily disallow buffers with
381 * Callback called before passing the first slice of a new frame. If
382 * NULL, the filter layer will default to storing a reference to the
383 * picture inside the link structure.
385 * Input video pads only.
387 void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
390 * Callback function to get a video buffer. If NULL, the filter system will
391 * use avfilter_default_get_video_buffer().
393 * Input video pads only.
395 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
398 * Callback function to get an audio buffer. If NULL, the filter system will
399 * use avfilter_default_get_audio_buffer().
401 * Input audio pads only.
403 AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms, int nb_samples);
406 * Callback called after the slices of a frame are completely sent. If
407 * NULL, the filter layer will default to releasing the reference stored
408 * in the link structure during start_frame().
410 * Input video pads only.
412 void (*end_frame)(AVFilterLink *link);
415 * Slice drawing callback. This is where a filter receives video data
416 * and should do its processing.
418 * Input video pads only.
420 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
423 * Samples filtering callback. This is where a filter receives audio data
424 * and should do its processing.
426 * Input audio pads only.
428 void (*filter_samples)(AVFilterLink *link, AVFilterBufferRef *samplesref);
431 * Frame poll callback. This returns the number of immediately available
432 * samples. It should return a positive value if the next request_frame()
433 * is guaranteed to return one frame (with no delay).
435 * Defaults to just calling the source poll_frame() method.
437 * Output video pads only.
439 int (*poll_frame)(AVFilterLink *link);
442 * Frame request callback. A call to this should result in at least one
443 * frame being output over the given link. This should return zero on
444 * success, and another value on error.
446 * Output video pads only.
448 int (*request_frame)(AVFilterLink *link);
451 * Link configuration callback.
453 * For output pads, this should set the following link properties:
454 * video: width, height, sample_aspect_ratio, time_base
455 * audio: sample_rate.
457 * This should NOT set properties such as format, channel_layout, etc which
458 * are negotiated between filters by the filter system using the
459 * query_formats() callback before this function is called.
461 * For input pads, this should check the properties of the link, and update
462 * the filter's internal state as necessary.
464 * For both input and output pads, this should return zero on success,
465 * and another value on error.
467 int (*config_props)(AVFilterLink *link);
470 /** default handler for start_frame() for video inputs */
471 void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
473 /** default handler for draw_slice() for video inputs */
474 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
476 /** default handler for end_frame() for video inputs */
477 void avfilter_default_end_frame(AVFilterLink *link);
479 /** default handler for filter_samples() for audio inputs */
480 void avfilter_default_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
482 /** default handler for get_video_buffer() for video inputs */
483 AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,
484 int perms, int w, int h);
486 /** default handler for get_audio_buffer() for audio inputs */
487 AVFilterBufferRef *avfilter_default_get_audio_buffer(AVFilterLink *link,
488 int perms, int nb_samples);
491 * Helpers for query_formats() which set all links to the same list of
492 * formats/layouts. If there are no links hooked to this filter, the list
493 * of formats is freed.
495 void avfilter_set_common_pixel_formats(AVFilterContext *ctx, AVFilterFormats *formats);
496 void avfilter_set_common_sample_formats(AVFilterContext *ctx, AVFilterFormats *formats);
497 void avfilter_set_common_channel_layouts(AVFilterContext *ctx, AVFilterFormats *formats);
498 void avfilter_set_common_packing_formats(AVFilterContext *ctx, AVFilterFormats *formats);
500 /** Default handler for query_formats() */
501 int avfilter_default_query_formats(AVFilterContext *ctx);
503 /** start_frame() handler for filters which simply pass video along */
504 void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
506 /** draw_slice() handler for filters which simply pass video along */
507 void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
509 /** end_frame() handler for filters which simply pass video along */
510 void avfilter_null_end_frame(AVFilterLink *link);
512 /** filter_samples() handler for filters which simply pass audio along */
513 void avfilter_null_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
515 /** get_video_buffer() handler for filters which simply pass video along */
516 AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link,
517 int perms, int w, int h);
519 /** get_audio_buffer() handler for filters which simply pass audio along */
520 AVFilterBufferRef *avfilter_null_get_audio_buffer(AVFilterLink *link,
521 int perms, int nb_samples);
524 * Filter definition. This defines the pads a filter contains, and all the
525 * callback functions used to interact with the filter.
527 typedef struct AVFilter {
528 const char *name; ///< filter name
530 int priv_size; ///< size of private data to allocate for the filter
533 * Filter initialization function. Args contains the user-supplied
534 * parameters. FIXME: maybe an AVOption-based system would be better?
535 * opaque is data provided by the code requesting creation of the filter,
536 * and is used to pass data to the filter.
538 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
541 * Filter uninitialization function. Should deallocate any memory held
542 * by the filter, release any buffer references, etc. This does not need
543 * to deallocate the AVFilterContext->priv memory itself.
545 void (*uninit)(AVFilterContext *ctx);
548 * Queries formats/layouts supported by the filter and its pads, and sets
549 * the in_formats/in_chlayouts for links connected to its output pads,
550 * and out_formats/out_chlayouts for links connected to its input pads.
552 * @return zero on success, a negative value corresponding to an
553 * AVERROR code otherwise
555 int (*query_formats)(AVFilterContext *);
557 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
558 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
561 * A description for the filter. You should use the
562 * NULL_IF_CONFIG_SMALL() macro to define it.
564 const char *description;
567 * Make the filter instance process a command.
569 * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
570 * @param arg the argument for the command
571 * @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.
572 * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
573 * time consuming then a filter should treat it like an unsupported command
575 * @returns >=0 on success otherwise an error code.
576 * AVERROR(ENOSYS) on unsupported commands
578 int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
581 /** An instance of a filter */
582 struct AVFilterContext {
583 const AVClass *av_class; ///< needed for av_log()
585 AVFilter *filter; ///< the AVFilter of which this is an instance
587 char *name; ///< name of this filter instance
589 unsigned input_count; ///< number of input pads
590 AVFilterPad *input_pads; ///< array of input pads
591 AVFilterLink **inputs; ///< array of pointers to input links
593 unsigned output_count; ///< number of output pads
594 AVFilterPad *output_pads; ///< array of output pads
595 AVFilterLink **outputs; ///< array of pointers to output links
597 void *priv; ///< private data for use by the filter
599 struct AVFilterCommand *command_queue;
602 enum AVFilterPacking {
608 * A link between two filters. This contains pointers to the source and
609 * destination filters between which this link exists, and the indexes of
610 * the pads involved. In addition, this link also contains the parameters
611 * which have been negotiated and agreed upon between the filter, such as
612 * image dimensions, format, etc.
614 struct AVFilterLink {
615 AVFilterContext *src; ///< source filter
616 AVFilterPad *srcpad; ///< output pad on the source filter
618 AVFilterContext *dst; ///< dest filter
619 AVFilterPad *dstpad; ///< input pad on the dest filter
621 /** stage of the initialization of the link properties (dimensions, etc) */
623 AVLINK_UNINIT = 0, ///< not started
624 AVLINK_STARTINIT, ///< started, but incomplete
625 AVLINK_INIT ///< complete
628 enum AVMediaType type; ///< filter media type
630 /* These parameters apply only to video */
631 int w; ///< agreed upon image width
632 int h; ///< agreed upon image height
633 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
634 /* These parameters apply only to audio */
635 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/audioconvert.h)
636 #if LIBAVFILTER_VERSION_MAJOR < 3
637 int64_t sample_rate; ///< samples per second
639 int sample_rate; ///< samples per second
641 int planar; ///< agreed upon packing mode of audio buffers. true if planar.
643 int format; ///< agreed upon media format
646 * Lists of formats and channel layouts supported by the input and output
647 * filters respectively. These lists are used for negotiating the format
648 * to actually be used, which will be loaded into the format and
649 * channel_layout members, above, when chosen.
652 AVFilterFormats *in_formats;
653 AVFilterFormats *out_formats;
655 AVFilterFormats *in_chlayouts;
656 AVFilterFormats *out_chlayouts;
657 AVFilterFormats *in_packing;
658 AVFilterFormats *out_packing;
661 * The buffer reference currently being sent across the link by the source
662 * filter. This is used internally by the filter system to allow
663 * automatic copying of buffers which do not have sufficient permissions
664 * for the destination. This should not be accessed directly by the
667 AVFilterBufferRef *src_buf;
669 AVFilterBufferRef *cur_buf;
670 AVFilterBufferRef *out_buf;
673 * Define the time base used by the PTS of the frames/samples
674 * which will pass through this link.
675 * During the configuration stage, each filter is supposed to
676 * change only the output timebase, while the timebase of the
677 * input link is assumed to be an unchangeable property.
679 AVRational time_base;
681 struct AVFilterPool *pool;
685 * Link two filters together.
687 * @param src the source filter
688 * @param srcpad index of the output pad on the source filter
689 * @param dst the destination filter
690 * @param dstpad index of the input pad on the destination filter
691 * @return zero on success
693 int avfilter_link(AVFilterContext *src, unsigned srcpad,
694 AVFilterContext *dst, unsigned dstpad);
697 * Free the link in *link, and set its pointer to NULL.
699 void avfilter_link_free(AVFilterLink **link);
702 * Negotiate the media format, dimensions, etc of all inputs to a filter.
704 * @param filter the filter to negotiate the properties for its inputs
705 * @return zero on successful negotiation
707 int avfilter_config_links(AVFilterContext *filter);
710 * Request a picture buffer with a specific set of permissions.
712 * @param link the output link to the filter from which the buffer will
714 * @param perms the required access permissions
715 * @param w the minimum width of the buffer to allocate
716 * @param h the minimum height of the buffer to allocate
717 * @return A reference to the buffer. This must be unreferenced with
718 * avfilter_unref_buffer when you are finished with it.
720 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
724 * Create a buffer reference wrapped around an already allocated image
727 * @param data pointers to the planes of the image to reference
728 * @param linesize linesizes for the planes of the image to reference
729 * @param perms the required access permissions
730 * @param w the width of the image specified by the data and linesize arrays
731 * @param h the height of the image specified by the data and linesize arrays
732 * @param format the pixel format of the image specified by the data and linesize arrays
735 avfilter_get_video_buffer_ref_from_arrays(uint8_t * const data[4], const int linesize[4], int perms,
736 int w, int h, enum PixelFormat format);
739 * Request an audio samples buffer with a specific set of permissions.
741 * @param link the output link to the filter from which the buffer will
743 * @param perms the required access permissions
744 * @param nb_samples the number of samples per channel
745 * @return A reference to the samples. This must be unreferenced with
746 * avfilter_unref_buffer when you are finished with it.
748 AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms,
752 * Create an audio buffer reference wrapped around an already
753 * allocated samples buffer.
755 * @param data pointers to the samples plane buffers
756 * @param linesize linesize for the samples plane buffers
757 * @param perms the required access permissions
758 * @param nb_samples number of samples per channel
759 * @param sample_fmt the format of each sample in the buffer to allocate
760 * @param channel_layout the channel layout of the buffer
761 * @param planar audio data layout - planar or packed
764 avfilter_get_audio_buffer_ref_from_arrays(uint8_t *data[8], int linesize[8], int perms,
765 int nb_samples, enum AVSampleFormat sample_fmt,
766 uint64_t channel_layout, int planar);
768 * Request an input frame from the filter at the other end of the link.
770 * @param link the input link
771 * @return zero on success
773 int avfilter_request_frame(AVFilterLink *link);
776 * Poll a frame from the filter chain.
778 * @param link the input link
779 * @return the number of immediately available frames, a negative
780 * number in case of error
782 int avfilter_poll_frame(AVFilterLink *link);
785 * Notify the next filter of the start of a frame.
787 * @param link the output link the frame will be sent over
788 * @param picref A reference to the frame about to be sent. The data for this
789 * frame need only be valid once draw_slice() is called for that
790 * portion. The receiving filter will free this reference when
791 * it no longer needs it.
793 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
796 * Notify the next filter that the current frame has finished.
798 * @param link the output link the frame was sent over
800 void avfilter_end_frame(AVFilterLink *link);
803 * Send a slice to the next filter.
805 * Slices have to be provided in sequential order, either in
806 * top-bottom or bottom-top order. If slices are provided in
807 * non-sequential order the behavior of the function is undefined.
809 * @param link the output link over which the frame is being sent
810 * @param y offset in pixels from the top of the image for this slice
811 * @param h height of this slice in pixels
812 * @param slice_dir the assumed direction for sending slices,
813 * from the top slice to the bottom slice if the value is 1,
814 * from the bottom slice to the top slice if the value is -1,
815 * for other values the behavior of the function is undefined.
817 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
819 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
820 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
823 * Make the filter instance process a command.
824 * It is recommended to use avfilter_graph_send_command().
826 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
829 * Send a buffer of audio samples to the next filter.
831 * @param link the output link over which the audio samples are being sent
832 * @param samplesref a reference to the buffer of audio samples being sent. The
833 * receiving filter will free this reference when it no longer
834 * needs it or pass it on to the next filter.
836 void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
838 /** Initialize the filter system. Register all built-in filters. */
839 void avfilter_register_all(void);
841 /** Uninitialize the filter system. Unregister all filters. */
842 void avfilter_uninit(void);
845 * Register a filter. This is only needed if you plan to use
846 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
847 * filter can still by instantiated with avfilter_open even if it is not
850 * @param filter the filter to register
851 * @return 0 if the registration was successful, a negative value
854 int avfilter_register(AVFilter *filter);
857 * Get a filter definition matching the given name.
859 * @param name the filter name to find
860 * @return the filter definition, if any matching one is registered.
861 * NULL if none found.
863 AVFilter *avfilter_get_by_name(const char *name);
866 * If filter is NULL, returns a pointer to the first registered filter pointer,
867 * if filter is non-NULL, returns the next pointer after filter.
868 * If the returned pointer points to NULL, the last registered filter
869 * was already reached.
871 AVFilter **av_filter_next(AVFilter **filter);
874 * Create a filter instance.
876 * @param filter_ctx put here a pointer to the created filter context
877 * on success, NULL on failure
878 * @param filter the filter to create an instance of
879 * @param inst_name Name to give to the new instance. Can be NULL for none.
880 * @return >= 0 in case of success, a negative error code otherwise
882 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
885 * Initialize a filter.
887 * @param filter the filter to initialize
888 * @param args A string of parameters to use when initializing the filter.
889 * The format and meaning of this string varies by filter.
890 * @param opaque Any extra non-string data needed by the filter. The meaning
891 * of this parameter varies by filter.
892 * @return zero on success
894 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
897 * Free a filter context.
899 * @param filter the filter to free
901 void avfilter_free(AVFilterContext *filter);
904 * Insert a filter in the middle of an existing link.
906 * @param link the link into which the filter should be inserted
907 * @param filt the filter to be inserted
908 * @param filt_srcpad_idx the input pad on the filter to connect
909 * @param filt_dstpad_idx the output pad on the filter to connect
910 * @return zero on success
912 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
913 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
918 * @param idx Insertion point. Pad is inserted at the end if this point
919 * is beyond the end of the list of pads.
920 * @param count Pointer to the number of pads in the list
921 * @param padidx_off Offset within an AVFilterLink structure to the element
922 * to increment when inserting a new pad causes link
923 * numbering to change
924 * @param pads Pointer to the pointer to the beginning of the list of pads
925 * @param links Pointer to the pointer to the beginning of the list of links
926 * @param newpad The new pad to add. A copy is made when adding.
928 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
929 AVFilterPad **pads, AVFilterLink ***links,
930 AVFilterPad *newpad);
932 /** Insert a new input pad for the filter. */
933 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
936 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
937 &f->input_pads, &f->inputs, p);
940 /** Insert a new output pad for the filter. */
941 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
944 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
945 &f->output_pads, &f->outputs, p);
948 #endif /* AVFILTER_AVFILTER_H */