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"
31 #define LIBAVFILTER_VERSION_MAJOR 2
32 #define LIBAVFILTER_VERSION_MINOR 53
33 #define LIBAVFILTER_VERSION_MICRO 0
35 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
36 LIBAVFILTER_VERSION_MINOR, \
37 LIBAVFILTER_VERSION_MICRO)
38 #define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
39 LIBAVFILTER_VERSION_MINOR, \
40 LIBAVFILTER_VERSION_MICRO)
41 #define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
43 #ifndef FF_API_OLD_VSINK_API
44 #define FF_API_OLD_VSINK_API (LIBAVFILTER_VERSION_MAJOR < 3)
46 #ifndef FF_API_OLD_ALL_FORMATS_API
47 #define FF_API_OLD_ALL_FORMATS_API (LIBAVFILTER_VERSION_MAJOR < 3)
53 * Return the LIBAVFILTER_VERSION_INT constant.
55 unsigned avfilter_version(void);
58 * Return the libavfilter build-time configuration.
60 const char *avfilter_configuration(void);
63 * Return the libavfilter license.
65 const char *avfilter_license(void);
68 typedef struct AVFilterContext AVFilterContext;
69 typedef struct AVFilterLink AVFilterLink;
70 typedef struct AVFilterPad AVFilterPad;
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
79 int linesize[8]; ///< number of bytes per line
81 unsigned refcount; ///< number of references to this buffer
83 /** private data to be used by a custom free function */
86 * A pointer to the function to deallocate this buffer if the default
87 * function is not sufficient. This could, for example, add the memory
88 * back into a memory pool to be reused later without the overhead of
89 * reallocating it from scratch.
91 void (*free)(struct AVFilterBuffer *buf);
93 int format; ///< media format
94 int w, h; ///< width and height of the allocated buffer
97 #define AV_PERM_READ 0x01 ///< can read from the buffer
98 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
99 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
100 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
101 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
102 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
103 #define AV_PERM_ALIGN 0x40 ///< the buffer must be aligned
105 #define AVFILTER_ALIGN 16 //not part of ABI
108 * Audio specific properties in a reference to an AVFilterBuffer. Since
109 * AVFilterBufferRef is common to different media formats, audio specific
110 * per reference properties must be separated out.
112 typedef struct AVFilterBufferRefAudioProps {
113 uint64_t channel_layout; ///< channel layout of audio buffer
114 int nb_samples; ///< number of audio samples per channel
115 int sample_rate; ///< audio buffer sample rate
116 int planar; ///< audio buffer - planar or packed
117 } AVFilterBufferRefAudioProps;
120 * Video specific properties in a reference to an AVFilterBuffer. Since
121 * AVFilterBufferRef is common to different media formats, video specific
122 * per reference properties must be separated out.
124 typedef struct AVFilterBufferRefVideoProps {
125 int w; ///< image width
126 int h; ///< image height
127 AVRational sample_aspect_ratio; ///< sample aspect ratio
128 int interlaced; ///< is frame interlaced
129 int top_field_first; ///< field order
130 enum AVPictureType pict_type; ///< picture type of the frame
131 int key_frame; ///< 1 -> keyframe, 0-> not
132 } AVFilterBufferRefVideoProps;
135 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
136 * a buffer to, for example, crop image without any memcpy, the buffer origin
137 * and dimensions are per-reference properties. Linesize is also useful for
138 * image flipping, frame to field filters, etc, and so is also per-reference.
140 * TODO: add anything necessary for frame reordering
142 typedef struct AVFilterBufferRef {
143 AVFilterBuffer *buf; ///< the buffer that this is a reference to
144 uint8_t *data[8]; ///< picture/audio data for each plane
145 int linesize[8]; ///< number of bytes per line
146 int format; ///< media format
149 * presentation timestamp. The time unit may change during
150 * filtering, as it is specified in the link and the filter code
151 * may need to rescale the PTS accordingly.
154 int64_t pos; ///< byte position in stream, -1 if unknown
156 int perms; ///< permissions, see the AV_PERM_* flags
158 enum AVMediaType type; ///< media type of buffer data
159 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
160 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
164 * Copy properties of src to dst, without copying the actual data
166 static inline void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src)
168 // copy common properties
173 case AVMEDIA_TYPE_VIDEO: *dst->video = *src->video; break;
174 case AVMEDIA_TYPE_AUDIO: *dst->audio = *src->audio; break;
180 * Add a new reference to a buffer.
182 * @param ref an existing reference to the buffer
183 * @param pmask a bitmask containing the allowable permissions in the new
185 * @return a new reference to the buffer with the same properties as the
186 * old, excluding any permissions denied by pmask
188 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
191 * Remove a reference to a buffer. If this is the last reference to the
192 * buffer, the buffer itself is also automatically freed.
194 * @param ref reference to the buffer, may be NULL
196 void avfilter_unref_buffer(AVFilterBufferRef *ref);
199 * A list of supported formats for one end of a filter link. This is used
200 * during the format negotiation process to try to pick the best format to
201 * use to minimize the number of necessary conversions. Each filter gives a
202 * list of the formats supported by each input and output pad. The list
203 * given for each pad need not be distinct - they may be references to the
204 * same list of formats, as is often the case when a filter supports multiple
205 * formats, but will always output the same format as it is given in input.
207 * In this way, a list of possible input formats and a list of possible
208 * output formats are associated with each link. When a set of formats is
209 * negotiated over a link, the input and output lists are merged to form a
210 * new list containing only the common elements of each list. In the case
211 * that there were no common elements, a format conversion is necessary.
212 * Otherwise, the lists are merged, and all other links which reference
213 * either of the format lists involved in the merge are also affected.
215 * For example, consider the filter chain:
216 * filter (a) --> (b) filter (b) --> (c) filter
218 * where the letters in parenthesis indicate a list of formats supported on
219 * the input or output of the link. Suppose the lists are as follows:
224 * First, the first link's lists are merged, yielding:
225 * filter (a) --> (a) filter (a) --> (c) filter
227 * Notice that format list (b) now refers to the same list as filter list (a).
228 * Next, the lists for the second link are merged, yielding:
229 * filter (a) --> (a) filter (a) --> (a) filter
233 * Unfortunately, when the format lists at the two ends of a link are merged,
234 * we must ensure that all links which reference either pre-merge format list
235 * get updated as well. Therefore, we have the format list structure store a
236 * pointer to each of the pointers to itself.
238 typedef struct AVFilterFormats {
239 unsigned format_count; ///< number of formats
240 int64_t *formats; ///< list of media formats
242 unsigned refcount; ///< number of references to this list
243 struct AVFilterFormats ***refs; ///< references to this list
247 * Create a list of supported formats. This is intended for use in
248 * AVFilter->query_formats().
250 * @param fmts list of media formats, terminated by -1. If NULL an
251 * empty list is created.
252 * @return the format list, with no existing references
254 AVFilterFormats *avfilter_make_format_list(const int *fmts);
255 AVFilterFormats *avfilter_make_format64_list(const int64_t *fmts);
258 * Add fmt to the list of media formats contained in *avff.
259 * If *avff is NULL the function allocates the filter formats struct
260 * and puts its pointer in *avff.
262 * @return a non negative value in case of success, or a negative
263 * value corresponding to an AVERROR code in case of error
265 int avfilter_add_format(AVFilterFormats **avff, int64_t fmt);
267 #if FF_API_OLD_ALL_FORMATS_API
269 * @deprecated Use avfilter_make_all_formats() instead.
272 AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
276 * Return a list of all formats supported by FFmpeg for the given media type.
278 AVFilterFormats *avfilter_make_all_formats(enum AVMediaType type);
281 * A list of all channel layouts supported by libavfilter.
283 extern const int64_t avfilter_all_channel_layouts[];
286 * Return a list of all channel layouts supported by FFmpeg.
288 AVFilterFormats *avfilter_make_all_channel_layouts(void);
291 * Return a list of all audio packing formats.
293 AVFilterFormats *avfilter_make_all_packing_formats(void);
296 * Return a format list which contains the intersection of the formats of
297 * a and b. Also, all the references of a, all the references of b, and
298 * a and b themselves will be deallocated.
300 * If a and b do not share any common formats, neither is modified, and NULL
303 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
306 * Add *ref as a new reference to formats.
307 * That is the pointers will point like in the ASCII art below:
309 * |formats |<--------.
310 * | ____ | ____|___________________
312 * | |* * | | | | | | AVFilterLink
313 * | |* *--------->|*ref|
314 * | |____| | | |____|
315 * |________| |________________________
317 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
320 * If *ref is non-NULL, remove *ref as a reference to the format list
321 * it currently points to, deallocates that list if this was the last
322 * reference, and sets *ref to NULL.
325 * ________ ________ NULL
326 * |formats |<--------. |formats | ^
327 * | ____ | ____|________________ | ____ | ____|________________
328 * | |refs| | | __|_ | |refs| | | __|_
329 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
330 * | |* *--------->|*ref| | |* | | | |*ref|
331 * | |____| | | |____| | |____| | | |____|
332 * |________| |_____________________ |________| |_____________________
334 void avfilter_formats_unref(AVFilterFormats **ref);
340 * |formats |<---------. |formats |<---------.
341 * | ____ | ___|___ | ____ | ___|___
342 * | |refs| | | | | | |refs| | | | | NULL
343 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
344 * | |* * | | |_______| | |* * | | |_______| ___|___
345 * | |____| | | |____| | | | |
346 * |________| |________| |*oldref|
349 void avfilter_formats_changeref(AVFilterFormats **oldref,
350 AVFilterFormats **newref);
353 * A filter pad used for either input or output.
357 * Pad name. The name is unique among inputs and among outputs, but an
358 * input may have the same name as an output. This may be NULL if this
359 * pad has no need to ever be referenced by name.
364 * AVFilterPad type. Can be AVMEDIA_TYPE_VIDEO or AVMEDIA_TYPE_AUDIO.
366 enum AVMediaType type;
369 * Minimum required permissions on incoming buffers. Any buffer with
370 * insufficient permissions will be automatically copied by the filter
371 * system to a new buffer which provides the needed access permissions.
378 * Permissions which are not accepted on incoming buffers. Any buffer
379 * which has any of these permissions set will be automatically copied
380 * by the filter system to a new buffer which does not have those
381 * permissions. This can be used to easily disallow buffers with
389 * Callback called before passing the first slice of a new frame. If
390 * NULL, the filter layer will default to storing a reference to the
391 * picture inside the link structure.
393 * Input video pads only.
395 void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
398 * Callback function to get a video buffer. If NULL, the filter system will
399 * use avfilter_default_get_video_buffer().
401 * Input video pads only.
403 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
406 * Callback function to get an audio buffer. If NULL, the filter system will
407 * use avfilter_default_get_audio_buffer().
409 * Input audio pads only.
411 AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms, int nb_samples);
414 * Callback called after the slices of a frame are completely sent. If
415 * NULL, the filter layer will default to releasing the reference stored
416 * in the link structure during start_frame().
418 * Input video pads only.
420 void (*end_frame)(AVFilterLink *link);
423 * Slice drawing callback. This is where a filter receives video data
424 * and should do its processing.
426 * Input video pads only.
428 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
431 * Samples filtering callback. This is where a filter receives audio data
432 * and should do its processing.
434 * Input audio pads only.
436 void (*filter_samples)(AVFilterLink *link, AVFilterBufferRef *samplesref);
439 * Frame poll callback. This returns the number of immediately available
440 * samples. It should return a positive value if the next request_frame()
441 * is guaranteed to return one frame (with no delay).
443 * Defaults to just calling the source poll_frame() method.
445 * Output video pads only.
447 int (*poll_frame)(AVFilterLink *link);
450 * Frame request callback. A call to this should result in at least one
451 * frame being output over the given link. This should return zero on
452 * success, and another value on error.
454 * Output video pads only.
456 int (*request_frame)(AVFilterLink *link);
459 * Link configuration callback.
461 * For output pads, this should set the following link properties:
462 * video: width, height, sample_aspect_ratio, time_base
463 * audio: sample_rate.
465 * This should NOT set properties such as format, channel_layout, etc which
466 * are negotiated between filters by the filter system using the
467 * query_formats() callback before this function is called.
469 * For input pads, this should check the properties of the link, and update
470 * the filter's internal state as necessary.
472 * For both input and output pads, this should return zero on success,
473 * and another value on error.
475 int (*config_props)(AVFilterLink *link);
478 /** default handler for start_frame() for video inputs */
479 void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
481 /** default handler for draw_slice() for video inputs */
482 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
484 /** default handler for end_frame() for video inputs */
485 void avfilter_default_end_frame(AVFilterLink *link);
487 /** default handler for filter_samples() for audio inputs */
488 void avfilter_default_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
490 /** default handler for get_video_buffer() for video inputs */
491 AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,
492 int perms, int w, int h);
494 /** default handler for get_audio_buffer() for audio inputs */
495 AVFilterBufferRef *avfilter_default_get_audio_buffer(AVFilterLink *link,
496 int perms, int nb_samples);
499 * Helpers for query_formats() which set all links to the same list of
500 * formats/layouts. If there are no links hooked to this filter, the list
501 * of formats is freed.
503 void avfilter_set_common_pixel_formats(AVFilterContext *ctx, AVFilterFormats *formats);
504 void avfilter_set_common_sample_formats(AVFilterContext *ctx, AVFilterFormats *formats);
505 void avfilter_set_common_channel_layouts(AVFilterContext *ctx, AVFilterFormats *formats);
506 void avfilter_set_common_packing_formats(AVFilterContext *ctx, AVFilterFormats *formats);
508 /** Default handler for query_formats() */
509 int avfilter_default_query_formats(AVFilterContext *ctx);
511 /** start_frame() handler for filters which simply pass video along */
512 void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
514 /** draw_slice() handler for filters which simply pass video along */
515 void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
517 /** end_frame() handler for filters which simply pass video along */
518 void avfilter_null_end_frame(AVFilterLink *link);
520 /** filter_samples() handler for filters which simply pass audio along */
521 void avfilter_null_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
523 /** get_video_buffer() handler for filters which simply pass video along */
524 AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link,
525 int perms, int w, int h);
527 /** get_audio_buffer() handler for filters which simply pass audio along */
528 AVFilterBufferRef *avfilter_null_get_audio_buffer(AVFilterLink *link,
529 int perms, int nb_samples);
532 * Filter definition. This defines the pads a filter contains, and all the
533 * callback functions used to interact with the filter.
535 typedef struct AVFilter {
536 const char *name; ///< filter name
538 int priv_size; ///< size of private data to allocate for the filter
541 * Filter initialization function. Args contains the user-supplied
542 * parameters. FIXME: maybe an AVOption-based system would be better?
543 * opaque is data provided by the code requesting creation of the filter,
544 * and is used to pass data to the filter.
546 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
549 * Filter uninitialization function. Should deallocate any memory held
550 * by the filter, release any buffer references, etc. This does not need
551 * to deallocate the AVFilterContext->priv memory itself.
553 void (*uninit)(AVFilterContext *ctx);
556 * Queries formats/layouts supported by the filter and its pads, and sets
557 * the in_formats/in_chlayouts for links connected to its output pads,
558 * and out_formats/out_chlayouts for links connected to its input pads.
560 * @return zero on success, a negative value corresponding to an
561 * AVERROR code otherwise
563 int (*query_formats)(AVFilterContext *);
565 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
566 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
569 * A description for the filter. You should use the
570 * NULL_IF_CONFIG_SMALL() macro to define it.
572 const char *description;
575 * Make the filter instance process a command.
577 * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
578 * @param arg the argument for the command
579 * @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.
580 * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
581 * time consuming then a filter should treat it like an unsupported command
583 * @returns >=0 on success otherwise an error code.
584 * AVERROR(ENOSYS) on unsupported commands
586 int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
589 /** An instance of a filter */
590 struct AVFilterContext {
591 const AVClass *av_class; ///< needed for av_log()
593 AVFilter *filter; ///< the AVFilter of which this is an instance
595 char *name; ///< name of this filter instance
597 unsigned input_count; ///< number of input pads
598 AVFilterPad *input_pads; ///< array of input pads
599 AVFilterLink **inputs; ///< array of pointers to input links
601 unsigned output_count; ///< number of output pads
602 AVFilterPad *output_pads; ///< array of output pads
603 AVFilterLink **outputs; ///< array of pointers to output links
605 void *priv; ///< private data for use by the filter
607 struct AVFilterCommand *command_queue;
610 enum AVFilterPacking {
616 * A link between two filters. This contains pointers to the source and
617 * destination filters between which this link exists, and the indexes of
618 * the pads involved. In addition, this link also contains the parameters
619 * which have been negotiated and agreed upon between the filter, such as
620 * image dimensions, format, etc.
622 struct AVFilterLink {
623 AVFilterContext *src; ///< source filter
624 AVFilterPad *srcpad; ///< output pad on the source filter
626 AVFilterContext *dst; ///< dest filter
627 AVFilterPad *dstpad; ///< input pad on the dest filter
629 /** stage of the initialization of the link properties (dimensions, etc) */
631 AVLINK_UNINIT = 0, ///< not started
632 AVLINK_STARTINIT, ///< started, but incomplete
633 AVLINK_INIT ///< complete
636 enum AVMediaType type; ///< filter media type
638 /* These parameters apply only to video */
639 int w; ///< agreed upon image width
640 int h; ///< agreed upon image height
641 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
642 /* These parameters apply only to audio */
643 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/audioconvert.h)
644 #if LIBAVFILTER_VERSION_MAJOR < 3
645 int64_t sample_rate; ///< samples per second
647 int sample_rate; ///< samples per second
649 int planar; ///< agreed upon packing mode of audio buffers. true if planar.
651 int format; ///< agreed upon media format
654 * Lists of formats and channel layouts supported by the input and output
655 * filters respectively. These lists are used for negotiating the format
656 * to actually be used, which will be loaded into the format and
657 * channel_layout members, above, when chosen.
660 AVFilterFormats *in_formats;
661 AVFilterFormats *out_formats;
663 AVFilterFormats *in_chlayouts;
664 AVFilterFormats *out_chlayouts;
665 AVFilterFormats *in_packing;
666 AVFilterFormats *out_packing;
669 * The buffer reference currently being sent across the link by the source
670 * filter. This is used internally by the filter system to allow
671 * automatic copying of buffers which do not have sufficient permissions
672 * for the destination. This should not be accessed directly by the
675 AVFilterBufferRef *src_buf;
677 AVFilterBufferRef *cur_buf;
678 AVFilterBufferRef *out_buf;
681 * Define the time base used by the PTS of the frames/samples
682 * which will pass through this link.
683 * During the configuration stage, each filter is supposed to
684 * change only the output timebase, while the timebase of the
685 * input link is assumed to be an unchangeable property.
687 AVRational time_base;
689 struct AVFilterPool *pool;
693 * Link two filters together.
695 * @param src the source filter
696 * @param srcpad index of the output pad on the source filter
697 * @param dst the destination filter
698 * @param dstpad index of the input pad on the destination filter
699 * @return zero on success
701 int avfilter_link(AVFilterContext *src, unsigned srcpad,
702 AVFilterContext *dst, unsigned dstpad);
705 * Free the link in *link, and set its pointer to NULL.
707 void avfilter_link_free(AVFilterLink **link);
710 * Negotiate the media format, dimensions, etc of all inputs to a filter.
712 * @param filter the filter to negotiate the properties for its inputs
713 * @return zero on successful negotiation
715 int avfilter_config_links(AVFilterContext *filter);
718 * Request a picture buffer with a specific set of permissions.
720 * @param link the output link to the filter from which the buffer will
722 * @param perms the required access permissions
723 * @param w the minimum width of the buffer to allocate
724 * @param h the minimum height of the buffer to allocate
725 * @return A reference to the buffer. This must be unreferenced with
726 * avfilter_unref_buffer when you are finished with it.
728 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
732 * Create a buffer reference wrapped around an already allocated image
735 * @param data pointers to the planes of the image to reference
736 * @param linesize linesizes for the planes of the image to reference
737 * @param perms the required access permissions
738 * @param w the width of the image specified by the data and linesize arrays
739 * @param h the height of the image specified by the data and linesize arrays
740 * @param format the pixel format of the image specified by the data and linesize arrays
743 avfilter_get_video_buffer_ref_from_arrays(uint8_t * const data[4], const int linesize[4], int perms,
744 int w, int h, enum PixelFormat format);
747 * Request an audio samples buffer with a specific set of permissions.
749 * @param link the output link to the filter from which the buffer will
751 * @param perms the required access permissions
752 * @param nb_samples the number of samples per channel
753 * @return A reference to the samples. This must be unreferenced with
754 * avfilter_unref_buffer when you are finished with it.
756 AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms,
760 * Create an audio buffer reference wrapped around an already
761 * allocated samples buffer.
763 * @param data pointers to the samples plane buffers
764 * @param linesize linesize for the samples plane buffers
765 * @param perms the required access permissions
766 * @param nb_samples number of samples per channel
767 * @param sample_fmt the format of each sample in the buffer to allocate
768 * @param channel_layout the channel layout of the buffer
769 * @param planar audio data layout - planar or packed
772 avfilter_get_audio_buffer_ref_from_arrays(uint8_t *data[8], int linesize[8], int perms,
773 int nb_samples, enum AVSampleFormat sample_fmt,
774 uint64_t channel_layout, int planar);
776 * Request an input frame from the filter at the other end of the link.
778 * @param link the input link
779 * @return zero on success
781 int avfilter_request_frame(AVFilterLink *link);
784 * Poll a frame from the filter chain.
786 * @param link the input link
787 * @return the number of immediately available frames, a negative
788 * number in case of error
790 int avfilter_poll_frame(AVFilterLink *link);
793 * Notify the next filter of the start of a frame.
795 * @param link the output link the frame will be sent over
796 * @param picref A reference to the frame about to be sent. The data for this
797 * frame need only be valid once draw_slice() is called for that
798 * portion. The receiving filter will free this reference when
799 * it no longer needs it.
801 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
804 * Notify the next filter that the current frame has finished.
806 * @param link the output link the frame was sent over
808 void avfilter_end_frame(AVFilterLink *link);
811 * Send a slice to the next filter.
813 * Slices have to be provided in sequential order, either in
814 * top-bottom or bottom-top order. If slices are provided in
815 * non-sequential order the behavior of the function is undefined.
817 * @param link the output link over which the frame is being sent
818 * @param y offset in pixels from the top of the image for this slice
819 * @param h height of this slice in pixels
820 * @param slice_dir the assumed direction for sending slices,
821 * from the top slice to the bottom slice if the value is 1,
822 * from the bottom slice to the top slice if the value is -1,
823 * for other values the behavior of the function is undefined.
825 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
827 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
828 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
831 * Make the filter instance process a command.
832 * It is recommended to use avfilter_graph_send_command().
834 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
837 * Send a buffer of audio samples to the next filter.
839 * @param link the output link over which the audio samples are being sent
840 * @param samplesref a reference to the buffer of audio samples being sent. The
841 * receiving filter will free this reference when it no longer
842 * needs it or pass it on to the next filter.
844 void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
846 /** Initialize the filter system. Register all built-in filters. */
847 void avfilter_register_all(void);
849 /** Uninitialize the filter system. Unregister all filters. */
850 void avfilter_uninit(void);
853 * Register a filter. This is only needed if you plan to use
854 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
855 * filter can still by instantiated with avfilter_open even if it is not
858 * @param filter the filter to register
859 * @return 0 if the registration was successful, a negative value
862 int avfilter_register(AVFilter *filter);
865 * Get a filter definition matching the given name.
867 * @param name the filter name to find
868 * @return the filter definition, if any matching one is registered.
869 * NULL if none found.
871 AVFilter *avfilter_get_by_name(const char *name);
874 * If filter is NULL, returns a pointer to the first registered filter pointer,
875 * if filter is non-NULL, returns the next pointer after filter.
876 * If the returned pointer points to NULL, the last registered filter
877 * was already reached.
879 AVFilter **av_filter_next(AVFilter **filter);
882 * Create a filter instance.
884 * @param filter_ctx put here a pointer to the created filter context
885 * on success, NULL on failure
886 * @param filter the filter to create an instance of
887 * @param inst_name Name to give to the new instance. Can be NULL for none.
888 * @return >= 0 in case of success, a negative error code otherwise
890 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
893 * Initialize a filter.
895 * @param filter the filter to initialize
896 * @param args A string of parameters to use when initializing the filter.
897 * The format and meaning of this string varies by filter.
898 * @param opaque Any extra non-string data needed by the filter. The meaning
899 * of this parameter varies by filter.
900 * @return zero on success
902 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
905 * Free a filter context.
907 * @param filter the filter to free
909 void avfilter_free(AVFilterContext *filter);
912 * Insert a filter in the middle of an existing link.
914 * @param link the link into which the filter should be inserted
915 * @param filt the filter to be inserted
916 * @param filt_srcpad_idx the input pad on the filter to connect
917 * @param filt_dstpad_idx the output pad on the filter to connect
918 * @return zero on success
920 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
921 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
926 * @param idx Insertion point. Pad is inserted at the end if this point
927 * is beyond the end of the list of pads.
928 * @param count Pointer to the number of pads in the list
929 * @param padidx_off Offset within an AVFilterLink structure to the element
930 * to increment when inserting a new pad causes link
931 * numbering to change
932 * @param pads Pointer to the pointer to the beginning of the list of pads
933 * @param links Pointer to the pointer to the beginning of the list of links
934 * @param newpad The new pad to add. A copy is made when adding.
936 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
937 AVFilterPad **pads, AVFilterLink ***links,
938 AVFilterPad *newpad);
940 /** Insert a new input pad for the filter. */
941 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
944 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
945 &f->input_pads, &f->inputs, p);
948 /** Insert a new output pad for the filter. */
949 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
952 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
953 &f->output_pads, &f->outputs, p);
956 #endif /* AVFILTER_AVFILTER_H */