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 39
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 (LIBAVUTIL_VERSION_MAJOR < 3)
50 * Return the LIBAVFILTER_VERSION_INT constant.
52 unsigned avfilter_version(void);
55 * Return the libavfilter build-time configuration.
57 const char *avfilter_configuration(void);
60 * Return the libavfilter license.
62 const char *avfilter_license(void);
65 typedef struct AVFilterContext AVFilterContext;
66 typedef struct AVFilterLink AVFilterLink;
67 typedef struct AVFilterPad AVFilterPad;
70 * A reference-counted buffer data type used by the filter system. Filters
71 * should not store pointers to this structure directly, but instead use the
72 * AVFilterBufferRef structure below.
74 typedef struct AVFilterBuffer {
75 uint8_t *data[8]; ///< buffer data for each plane/channel
76 int linesize[8]; ///< number of bytes per line
78 unsigned refcount; ///< number of references to this buffer
80 /** private data to be used by a custom free function */
83 * A pointer to the function to deallocate this buffer if the default
84 * function is not sufficient. This could, for example, add the memory
85 * back into a memory pool to be reused later without the overhead of
86 * reallocating it from scratch.
88 void (*free)(struct AVFilterBuffer *buf);
90 int format; ///< media format
91 int w, h; ///< width and height of the allocated buffer
94 #define AV_PERM_READ 0x01 ///< can read from the buffer
95 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
96 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
97 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
98 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
99 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
102 * Audio specific properties in a reference to an AVFilterBuffer. Since
103 * AVFilterBufferRef is common to different media formats, audio specific
104 * per reference properties must be separated out.
106 typedef struct AVFilterBufferRefAudioProps {
107 int64_t channel_layout; ///< channel layout of audio buffer
108 int nb_samples; ///< number of audio samples per channel
109 uint32_t sample_rate; ///< audio buffer sample rate
110 int planar; ///< audio buffer - planar or packed
111 } AVFilterBufferRefAudioProps;
114 * Video specific properties in a reference to an AVFilterBuffer. Since
115 * AVFilterBufferRef is common to different media formats, video specific
116 * per reference properties must be separated out.
118 typedef struct AVFilterBufferRefVideoProps {
119 int w; ///< image width
120 int h; ///< image height
121 AVRational sample_aspect_ratio; ///< sample aspect ratio
122 int interlaced; ///< is frame interlaced
123 int top_field_first; ///< field order
124 enum AVPictureType pict_type; ///< picture type of the frame
125 int key_frame; ///< 1 -> keyframe, 0-> not
126 } AVFilterBufferRefVideoProps;
129 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
130 * a buffer to, for example, crop image without any memcpy, the buffer origin
131 * and dimensions are per-reference properties. Linesize is also useful for
132 * image flipping, frame to field filters, etc, and so is also per-reference.
134 * TODO: add anything necessary for frame reordering
136 typedef struct AVFilterBufferRef {
137 AVFilterBuffer *buf; ///< the buffer that this is a reference to
138 uint8_t *data[8]; ///< picture/audio data for each plane
139 int linesize[8]; ///< number of bytes per line
140 int format; ///< media format
143 * presentation timestamp. The time unit may change during
144 * filtering, as it is specified in the link and the filter code
145 * may need to rescale the PTS accordingly.
148 int64_t pos; ///< byte position in stream, -1 if unknown
150 int perms; ///< permissions, see the AV_PERM_* flags
152 enum AVMediaType type; ///< media type of buffer data
153 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
154 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
158 * Copy properties of src to dst, without copying the actual data
160 static inline void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src)
162 // copy common properties
167 case AVMEDIA_TYPE_VIDEO: *dst->video = *src->video; break;
168 case AVMEDIA_TYPE_AUDIO: *dst->audio = *src->audio; break;
174 * Add a new reference to a buffer.
176 * @param ref an existing reference to the buffer
177 * @param pmask a bitmask containing the allowable permissions in the new
179 * @return a new reference to the buffer with the same properties as the
180 * old, excluding any permissions denied by pmask
182 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
185 * Remove a reference to a buffer. If this is the last reference to the
186 * buffer, the buffer itself is also automatically freed.
188 * @param ref reference to the buffer, may be NULL
190 void avfilter_unref_buffer(AVFilterBufferRef *ref);
193 * A list of supported formats for one end of a filter link. This is used
194 * during the format negotiation process to try to pick the best format to
195 * use to minimize the number of necessary conversions. Each filter gives a
196 * list of the formats supported by each input and output pad. The list
197 * given for each pad need not be distinct - they may be references to the
198 * same list of formats, as is often the case when a filter supports multiple
199 * formats, but will always output the same format as it is given in input.
201 * In this way, a list of possible input formats and a list of possible
202 * output formats are associated with each link. When a set of formats is
203 * negotiated over a link, the input and output lists are merged to form a
204 * new list containing only the common elements of each list. In the case
205 * that there were no common elements, a format conversion is necessary.
206 * Otherwise, the lists are merged, and all other links which reference
207 * either of the format lists involved in the merge are also affected.
209 * For example, consider the filter chain:
210 * filter (a) --> (b) filter (b) --> (c) filter
212 * where the letters in parenthesis indicate a list of formats supported on
213 * the input or output of the link. Suppose the lists are as follows:
218 * First, the first link's lists are merged, yielding:
219 * filter (a) --> (a) filter (a) --> (c) filter
221 * Notice that format list (b) now refers to the same list as filter list (a).
222 * Next, the lists for the second link are merged, yielding:
223 * filter (a) --> (a) filter (a) --> (a) filter
227 * Unfortunately, when the format lists at the two ends of a link are merged,
228 * we must ensure that all links which reference either pre-merge format list
229 * get updated as well. Therefore, we have the format list structure store a
230 * pointer to each of the pointers to itself.
232 typedef struct AVFilterFormats {
233 unsigned format_count; ///< number of formats
234 int64_t *formats; ///< list of media formats
236 unsigned refcount; ///< number of references to this list
237 struct AVFilterFormats ***refs; ///< references to this list
241 * Create a list of supported formats. This is intended for use in
242 * AVFilter->query_formats().
244 * @param fmts list of media formats, terminated by -1. If NULL an
245 * empty list is created.
246 * @return the format list, with no existing references
248 AVFilterFormats *avfilter_make_format_list(const int *fmts);
249 AVFilterFormats *avfilter_make_format64_list(const int64_t *fmts);
252 * Add fmt to the list of media formats contained in *avff.
253 * If *avff is NULL the function allocates the filter formats struct
254 * and puts its pointer in *avff.
256 * @return a non negative value in case of success, or a negative
257 * value corresponding to an AVERROR code in case of error
259 int avfilter_add_format(AVFilterFormats **avff, int64_t fmt);
262 * Return a list of all formats supported by FFmpeg for the given media type.
264 AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
267 * Return a list of all channel layouts supported by FFmpeg.
269 AVFilterFormats *avfilter_all_channel_layouts(void);
272 * Return a list of all audio packing formats.
274 AVFilterFormats *avfilter_all_packing_formats(void);
277 * Return a format list which contains the intersection of the formats of
278 * a and b. Also, all the references of a, all the references of b, and
279 * a and b themselves will be deallocated.
281 * If a and b do not share any common formats, neither is modified, and NULL
284 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
287 * Add *ref as a new reference to formats.
288 * That is the pointers will point like in the ascii art below:
290 * |formats |<--------.
291 * | ____ | ____|___________________
293 * | |* * | | | | | | AVFilterLink
294 * | |* *--------->|*ref|
295 * | |____| | | |____|
296 * |________| |________________________
298 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
301 * If *ref is non-NULL, remove *ref as a reference to the format list
302 * it currently points to, deallocates that list if this was the last
303 * reference, and sets *ref to NULL.
306 * ________ ________ NULL
307 * |formats |<--------. |formats | ^
308 * | ____ | ____|________________ | ____ | ____|________________
309 * | |refs| | | __|_ | |refs| | | __|_
310 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
311 * | |* *--------->|*ref| | |* | | | |*ref|
312 * | |____| | | |____| | |____| | | |____|
313 * |________| |_____________________ |________| |_____________________
315 void avfilter_formats_unref(AVFilterFormats **ref);
321 * |formats |<---------. |formats |<---------.
322 * | ____ | ___|___ | ____ | ___|___
323 * | |refs| | | | | | |refs| | | | | NULL
324 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
325 * | |* * | | |_______| | |* * | | |_______| ___|___
326 * | |____| | | |____| | | | |
327 * |________| |________| |*oldref|
330 void avfilter_formats_changeref(AVFilterFormats **oldref,
331 AVFilterFormats **newref);
334 * A filter pad used for either input or output.
338 * Pad name. The name is unique among inputs and among outputs, but an
339 * input may have the same name as an output. This may be NULL if this
340 * pad has no need to ever be referenced by name.
345 * AVFilterPad type. Only video supported now, hopefully someone will
346 * add audio in the future.
348 enum AVMediaType type;
351 * Minimum required permissions on incoming buffers. Any buffer with
352 * insufficient permissions will be automatically copied by the filter
353 * system to a new buffer which provides the needed access permissions.
360 * Permissions which are not accepted on incoming buffers. Any buffer
361 * which has any of these permissions set will be automatically copied
362 * by the filter system to a new buffer which does not have those
363 * permissions. This can be used to easily disallow buffers with
371 * Callback called before passing the first slice of a new frame. If
372 * NULL, the filter layer will default to storing a reference to the
373 * picture inside the link structure.
375 * Input video pads only.
377 void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
380 * Callback function to get a video buffer. If NULL, the filter system will
381 * use avfilter_default_get_video_buffer().
383 * Input video pads only.
385 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
388 * Callback function to get an audio buffer. If NULL, the filter system will
389 * use avfilter_default_get_audio_buffer().
391 * Input audio pads only.
393 AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms,
394 enum AVSampleFormat sample_fmt, int nb_samples,
395 int64_t channel_layout, int planar);
398 * Callback called after the slices of a frame are completely sent. If
399 * NULL, the filter layer will default to releasing the reference stored
400 * in the link structure during start_frame().
402 * Input video pads only.
404 void (*end_frame)(AVFilterLink *link);
407 * Slice drawing callback. This is where a filter receives video data
408 * and should do its processing.
410 * Input video pads only.
412 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
415 * Samples filtering callback. This is where a filter receives audio data
416 * and should do its processing.
418 * Input audio pads only.
420 void (*filter_samples)(AVFilterLink *link, AVFilterBufferRef *samplesref);
423 * Frame poll callback. This returns the number of immediately available
424 * samples. It should return a positive value if the next request_frame()
425 * is guaranteed to return one frame (with no delay).
427 * Defaults to just calling the source poll_frame() method.
429 * Output video pads only.
431 int (*poll_frame)(AVFilterLink *link);
434 * Frame request callback. A call to this should result in at least one
435 * frame being output over the given link. This should return zero on
436 * success, and another value on error.
438 * Output video pads only.
440 int (*request_frame)(AVFilterLink *link);
443 * Link configuration callback.
445 * For output pads, this should set the following link properties:
446 * video: width, height, sample_aspect_ratio, time_base
447 * audio: sample_rate.
449 * This should NOT set properties such as format, channel_layout, etc which
450 * are negotiated between filters by the filter system using the
451 * query_formats() callback before this function is called.
453 * For input pads, this should check the properties of the link, and update
454 * the filter's internal state as necessary.
456 * For both input and output pads, this should return zero on success,
457 * and another value on error.
459 int (*config_props)(AVFilterLink *link);
462 /** default handler for start_frame() for video inputs */
463 void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
465 /** default handler for draw_slice() for video inputs */
466 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
468 /** default handler for end_frame() for video inputs */
469 void avfilter_default_end_frame(AVFilterLink *link);
471 /** default handler for filter_samples() for audio inputs */
472 void avfilter_default_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
474 /** default handler for get_video_buffer() for video inputs */
475 AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,
476 int perms, int w, int h);
478 /** default handler for get_audio_buffer() for audio inputs */
479 AVFilterBufferRef *avfilter_default_get_audio_buffer(AVFilterLink *link, int perms,
480 enum AVSampleFormat sample_fmt, int nb_samples,
481 int64_t channel_layout, int planar);
484 * Helpers for query_formats() which set all links to the same list of
485 * formats/layouts. If there are no links hooked to this filter, the list
486 * of formats is freed.
488 void avfilter_set_common_pixel_formats(AVFilterContext *ctx, AVFilterFormats *formats);
489 void avfilter_set_common_sample_formats(AVFilterContext *ctx, AVFilterFormats *formats);
490 void avfilter_set_common_channel_layouts(AVFilterContext *ctx, AVFilterFormats *formats);
491 void avfilter_set_common_packing_formats(AVFilterContext *ctx, AVFilterFormats *formats);
493 /** Default handler for query_formats() */
494 int avfilter_default_query_formats(AVFilterContext *ctx);
496 /** start_frame() handler for filters which simply pass video along */
497 void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
499 /** draw_slice() handler for filters which simply pass video along */
500 void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
502 /** end_frame() handler for filters which simply pass video along */
503 void avfilter_null_end_frame(AVFilterLink *link);
505 /** filter_samples() handler for filters which simply pass audio along */
506 void avfilter_null_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
508 /** get_video_buffer() handler for filters which simply pass video along */
509 AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link,
510 int perms, int w, int h);
512 /** get_audio_buffer() handler for filters which simply pass audio along */
513 AVFilterBufferRef *avfilter_null_get_audio_buffer(AVFilterLink *link, int perms,
514 enum AVSampleFormat sample_fmt, int size,
515 int64_t channel_layout, int planar);
518 * Filter definition. This defines the pads a filter contains, and all the
519 * callback functions used to interact with the filter.
521 typedef struct AVFilter {
522 const char *name; ///< filter name
524 int priv_size; ///< size of private data to allocate for the filter
527 * Filter initialization function. Args contains the user-supplied
528 * parameters. FIXME: maybe an AVOption-based system would be better?
529 * opaque is data provided by the code requesting creation of the filter,
530 * and is used to pass data to the filter.
532 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
535 * Filter uninitialization function. Should deallocate any memory held
536 * by the filter, release any buffer references, etc. This does not need
537 * to deallocate the AVFilterContext->priv memory itself.
539 void (*uninit)(AVFilterContext *ctx);
542 * Queries formats/layouts supported by the filter and its pads, and sets
543 * the in_formats/in_chlayouts for links connected to its output pads,
544 * and out_formats/out_chlayouts for links connected to its input pads.
546 * @return zero on success, a negative value corresponding to an
547 * AVERROR code otherwise
549 int (*query_formats)(AVFilterContext *);
551 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
552 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
555 * A description for the filter. You should use the
556 * NULL_IF_CONFIG_SMALL() macro to define it.
558 const char *description;
561 * Make the filter instance process a command.
563 * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
564 * @param arg the argument for the command
565 * @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.
566 * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
567 * timeconsuming then a filter should treat it like an unsupported command
569 * @returns >=0 on success otherwise an error code.
570 * AVERROR(ENOSYS) on unsupported commands
572 int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
575 /** An instance of a filter */
576 struct AVFilterContext {
577 const AVClass *av_class; ///< needed for av_log()
579 AVFilter *filter; ///< the AVFilter of which this is an instance
581 char *name; ///< name of this filter instance
583 unsigned input_count; ///< number of input pads
584 AVFilterPad *input_pads; ///< array of input pads
585 AVFilterLink **inputs; ///< array of pointers to input links
587 unsigned output_count; ///< number of output pads
588 AVFilterPad *output_pads; ///< array of output pads
589 AVFilterLink **outputs; ///< array of pointers to output links
591 void *priv; ///< private data for use by the filter
593 struct AVFilterCommand *command_queue;
596 enum AVFilterPacking {
602 * A link between two filters. This contains pointers to the source and
603 * destination filters between which this link exists, and the indexes of
604 * the pads involved. In addition, this link also contains the parameters
605 * which have been negotiated and agreed upon between the filter, such as
606 * image dimensions, format, etc.
608 struct AVFilterLink {
609 AVFilterContext *src; ///< source filter
610 AVFilterPad *srcpad; ///< output pad on the source filter
612 AVFilterContext *dst; ///< dest filter
613 AVFilterPad *dstpad; ///< input pad on the dest filter
615 /** stage of the initialization of the link properties (dimensions, etc) */
617 AVLINK_UNINIT = 0, ///< not started
618 AVLINK_STARTINIT, ///< started, but incomplete
619 AVLINK_INIT ///< complete
622 enum AVMediaType type; ///< filter media type
624 /* These parameters apply only to video */
625 int w; ///< agreed upon image width
626 int h; ///< agreed upon image height
627 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
628 /* These parameters apply only to audio */
629 int64_t channel_layout; ///< channel layout of current buffer (see libavutil/audioconvert.h)
630 int64_t sample_rate; ///< samples per second
631 int planar; ///< agreed upon packing mode of audio buffers. true if planar.
633 int format; ///< agreed upon media format
636 * Lists of formats and channel layouts supported by the input and output
637 * filters respectively. These lists are used for negotiating the format
638 * to actually be used, which will be loaded into the format and
639 * channel_layout members, above, when chosen.
642 AVFilterFormats *in_formats;
643 AVFilterFormats *out_formats;
645 AVFilterFormats *in_chlayouts;
646 AVFilterFormats *out_chlayouts;
647 AVFilterFormats *in_packing;
648 AVFilterFormats *out_packing;
651 * The buffer reference currently being sent across the link by the source
652 * filter. This is used internally by the filter system to allow
653 * automatic copying of buffers which do not have sufficient permissions
654 * for the destination. This should not be accessed directly by the
657 AVFilterBufferRef *src_buf;
659 AVFilterBufferRef *cur_buf;
660 AVFilterBufferRef *out_buf;
663 * Define the time base used by the PTS of the frames/samples
664 * which will pass through this link.
665 * During the configuration stage, each filter is supposed to
666 * change only the output timebase, while the timebase of the
667 * input link is assumed to be an unchangeable property.
669 AVRational time_base;
671 struct AVFilterPool *pool;
675 * Link two filters together.
677 * @param src the source filter
678 * @param srcpad index of the output pad on the source filter
679 * @param dst the destination filter
680 * @param dstpad index of the input pad on the destination filter
681 * @return zero on success
683 int avfilter_link(AVFilterContext *src, unsigned srcpad,
684 AVFilterContext *dst, unsigned dstpad);
687 * Free the link in *link, and set its pointer to NULL.
689 void avfilter_link_free(AVFilterLink **link);
692 * Negotiate the media format, dimensions, etc of all inputs to a filter.
694 * @param filter the filter to negotiate the properties for its inputs
695 * @return zero on successful negotiation
697 int avfilter_config_links(AVFilterContext *filter);
700 * Request a picture buffer with a specific set of permissions.
702 * @param link the output link to the filter from which the buffer will
704 * @param perms the required access permissions
705 * @param w the minimum width of the buffer to allocate
706 * @param h the minimum height of the buffer to allocate
707 * @return A reference to the buffer. This must be unreferenced with
708 * avfilter_unref_buffer when you are finished with it.
710 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
714 * Create a buffer reference wrapped around an already allocated image
717 * @param data pointers to the planes of the image to reference
718 * @param linesize linesizes for the planes of the image to reference
719 * @param perms the required access permissions
720 * @param w the width of the image specified by the data and linesize arrays
721 * @param h the height of the image specified by the data and linesize arrays
722 * @param format the pixel format of the image specified by the data and linesize arrays
725 avfilter_get_video_buffer_ref_from_arrays(uint8_t * const data[4], const int linesize[4], int perms,
726 int w, int h, enum PixelFormat format);
729 * Request an audio samples buffer with a specific set of permissions.
731 * @param link the output link to the filter from which the buffer will
733 * @param perms the required access permissions
734 * @param sample_fmt the format of each sample in the buffer to allocate
735 * @param nb_samples the number of samples per channel
736 * @param channel_layout the number and type of channels per sample in the buffer to allocate
737 * @param planar audio data layout - planar or packed
738 * @return A reference to the samples. This must be unreferenced with
739 * avfilter_unref_buffer when you are finished with it.
741 AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms,
742 enum AVSampleFormat sample_fmt, int nb_samples,
743 int64_t channel_layout, int planar);
746 * Create an audio buffer reference wrapped around an already
747 * allocated samples buffer.
749 * @param data pointers to the samples plane buffers
750 * @param linesize linesize for the samples plane buffers
751 * @param perms the required access permissions
752 * @param nb_samples number of samples per channel
753 * @param sample_fmt the format of each sample in the buffer to allocate
754 * @param channel_layout the channel layout of the buffer
755 * @param planar audio data layout - planar or packed
758 avfilter_get_audio_buffer_ref_from_arrays(uint8_t *data[8], int linesize[8], int perms,
759 int nb_samples, enum AVSampleFormat sample_fmt,
760 int64_t channel_layout, int planar);
763 * Request an input frame from the filter at the other end of the link.
765 * @param link the input link
766 * @return zero on success
768 int avfilter_request_frame(AVFilterLink *link);
771 * Poll a frame from the filter chain.
773 * @param link the input link
774 * @return the number of immediately available frames, a negative
775 * number in case of error
777 int avfilter_poll_frame(AVFilterLink *link);
780 * Notifie the next filter of the start of a frame.
782 * @param link the output link the frame will be sent over
783 * @param picref A reference to the frame about to be sent. The data for this
784 * frame need only be valid once draw_slice() is called for that
785 * portion. The receiving filter will free this reference when
786 * it no longer needs it.
788 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
791 * Notifie the next filter that the current frame has finished.
793 * @param link the output link the frame was sent over
795 void avfilter_end_frame(AVFilterLink *link);
798 * Send a slice to the next filter.
800 * Slices have to be provided in sequential order, either in
801 * top-bottom or bottom-top order. If slices are provided in
802 * non-sequential order the behavior of the function is undefined.
804 * @param link the output link over which the frame is being sent
805 * @param y offset in pixels from the top of the image for this slice
806 * @param h height of this slice in pixels
807 * @param slice_dir the assumed direction for sending slices,
808 * from the top slice to the bottom slice if the value is 1,
809 * from the bottom slice to the top slice if the value is -1,
810 * for other values the behavior of the function is undefined.
812 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
814 #define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
815 #define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
818 * Make the filter instance process a command.
819 * It is recommanded to use avfilter_graph_send_command().
821 int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
824 * Send a buffer of audio samples to the next filter.
826 * @param link the output link over which the audio samples are being sent
827 * @param samplesref a reference to the buffer of audio samples being sent. The
828 * receiving filter will free this reference when it no longer
829 * needs it or pass it on to the next filter.
831 void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
833 /** Initialize the filter system. Register all builtin filters. */
834 void avfilter_register_all(void);
836 /** Uninitialize the filter system. Unregister all filters. */
837 void avfilter_uninit(void);
840 * Register a filter. This is only needed if you plan to use
841 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
842 * filter can still by instantiated with avfilter_open even if it is not
845 * @param filter the filter to register
846 * @return 0 if the registration was succesfull, a negative value
849 int avfilter_register(AVFilter *filter);
852 * Get a filter definition matching the given name.
854 * @param name the filter name to find
855 * @return the filter definition, if any matching one is registered.
856 * NULL if none found.
858 AVFilter *avfilter_get_by_name(const char *name);
861 * If filter is NULL, returns a pointer to the first registered filter pointer,
862 * if filter is non-NULL, returns the next pointer after filter.
863 * If the returned pointer points to NULL, the last registered filter
864 * was already reached.
866 AVFilter **av_filter_next(AVFilter **filter);
869 * Create a filter instance.
871 * @param filter_ctx put here a pointer to the created filter context
872 * on success, NULL on failure
873 * @param filter the filter to create an instance of
874 * @param inst_name Name to give to the new instance. Can be NULL for none.
875 * @return >= 0 in case of success, a negative error code otherwise
877 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
880 * Initialize a filter.
882 * @param filter the filter to initialize
883 * @param args A string of parameters to use when initializing the filter.
884 * The format and meaning of this string varies by filter.
885 * @param opaque Any extra non-string data needed by the filter. The meaning
886 * of this parameter varies by filter.
887 * @return zero on success
889 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
892 * Free a filter context.
894 * @param filter the filter to free
896 void avfilter_free(AVFilterContext *filter);
899 * Insert a filter in the middle of an existing link.
901 * @param link the link into which the filter should be inserted
902 * @param filt the filter to be inserted
903 * @param filt_srcpad_idx the input pad on the filter to connect
904 * @param filt_dstpad_idx the output pad on the filter to connect
905 * @return zero on success
907 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
908 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
913 * @param idx Insertion point. Pad is inserted at the end if this point
914 * is beyond the end of the list of pads.
915 * @param count Pointer to the number of pads in the list
916 * @param padidx_off Offset within an AVFilterLink structure to the element
917 * to increment when inserting a new pad causes link
918 * numbering to change
919 * @param pads Pointer to the pointer to the beginning of the list of pads
920 * @param links Pointer to the pointer to the beginning of the list of links
921 * @param newpad The new pad to add. A copy is made when adding.
923 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
924 AVFilterPad **pads, AVFilterLink ***links,
925 AVFilterPad *newpad);
927 /** Insert a new input pad for the filter. */
928 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
931 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
932 &f->input_pads, &f->inputs, p);
935 /** Insert a new output pad for the filter. */
936 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
939 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
940 &f->output_pads, &f->outputs, p);
943 #endif /* AVFILTER_AVFILTER_H */