3 * Copyright (c) 2007 Bobby Bingham
5 * This file is part of Libav.
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #ifndef AVFILTER_AVFILTER_H
23 #define AVFILTER_AVFILTER_H
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"
34 #include "libavfilter/version.h"
37 * Return the LIBAVFILTER_VERSION_INT constant.
39 unsigned avfilter_version(void);
42 * Return the libavfilter build-time configuration.
44 const char *avfilter_configuration(void);
47 * Return the libavfilter license.
49 const char *avfilter_license(void);
52 typedef struct AVFilterContext AVFilterContext;
53 typedef struct AVFilterLink AVFilterLink;
54 typedef struct AVFilterPad AVFilterPad;
55 typedef struct AVFilterFormats AVFilterFormats;
58 * A reference-counted buffer data type used by the filter system. Filters
59 * should not store pointers to this structure directly, but instead use the
60 * AVFilterBufferRef structure below.
62 typedef struct AVFilterBuffer {
63 uint8_t *data[8]; ///< buffer data for each plane/channel
64 int linesize[8]; ///< number of bytes per line
66 unsigned refcount; ///< number of references to this buffer
68 /** private data to be used by a custom free function */
71 * A pointer to the function to deallocate this buffer if the default
72 * function is not sufficient. This could, for example, add the memory
73 * back into a memory pool to be reused later without the overhead of
74 * reallocating it from scratch.
76 void (*free)(struct AVFilterBuffer *buf);
78 int format; ///< media format
79 int w, h; ///< width and height of the allocated buffer
82 * pointers to the data planes/channels.
84 * For video, this should simply point to data[].
86 * For planar audio, each channel has a separate data pointer, and
87 * linesize[0] contains the size of each channel buffer.
88 * For packed audio, there is just one data pointer, and linesize[0]
89 * contains the total size of the buffer for all channels.
91 * Note: Both data and extended_data will always be set, but for planar
92 * audio with more channels that can fit in data, extended_data must be used
93 * in order to access all channels.
95 uint8_t **extended_data;
98 #define AV_PERM_READ 0x01 ///< can read from the buffer
99 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
100 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
101 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
102 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
103 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
106 * Audio specific properties in a reference to an AVFilterBuffer. Since
107 * AVFilterBufferRef is common to different media formats, audio specific
108 * per reference properties must be separated out.
110 typedef struct AVFilterBufferRefAudioProps {
111 uint64_t channel_layout; ///< channel layout of audio buffer
112 int nb_samples; ///< number of audio samples
113 int sample_rate; ///< audio buffer sample rate
114 int planar; ///< audio buffer - planar or packed
115 } AVFilterBufferRefAudioProps;
118 * Video specific properties in a reference to an AVFilterBuffer. Since
119 * AVFilterBufferRef is common to different media formats, video specific
120 * per reference properties must be separated out.
122 typedef struct AVFilterBufferRefVideoProps {
123 int w; ///< image width
124 int h; ///< image height
125 AVRational pixel_aspect; ///< pixel aspect ratio
126 int interlaced; ///< is frame interlaced
127 int top_field_first; ///< field order
128 enum AVPictureType pict_type; ///< picture type of the frame
129 int key_frame; ///< 1 -> keyframe, 0-> not
130 } AVFilterBufferRefVideoProps;
133 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
134 * a buffer to, for example, crop image without any memcpy, the buffer origin
135 * and dimensions are per-reference properties. Linesize is also useful for
136 * image flipping, frame to field filters, etc, and so is also per-reference.
138 * TODO: add anything necessary for frame reordering
140 typedef struct AVFilterBufferRef {
141 AVFilterBuffer *buf; ///< the buffer that this is a reference to
142 uint8_t *data[8]; ///< picture/audio data for each plane
143 int linesize[8]; ///< number of bytes per line
144 int format; ///< media format
147 * presentation timestamp. The time unit may change during
148 * filtering, as it is specified in the link and the filter code
149 * may need to rescale the PTS accordingly.
152 int64_t pos; ///< byte position in stream, -1 if unknown
154 int perms; ///< permissions, see the AV_PERM_* flags
156 enum AVMediaType type; ///< media type of buffer data
157 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
158 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
161 * pointers to the data planes/channels.
163 * For video, this should simply point to data[].
165 * For planar audio, each channel has a separate data pointer, and
166 * linesize[0] contains the size of each channel buffer.
167 * For packed audio, there is just one data pointer, and linesize[0]
168 * contains the total size of the buffer for all channels.
170 * Note: Both data and extended_data will always be set, but for planar
171 * audio with more channels that can fit in data, extended_data must be used
172 * in order to access all channels.
174 uint8_t **extended_data;
178 * Copy properties of src to dst, without copying the actual data
180 void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src);
183 * Add a new reference to a buffer.
185 * @param ref an existing reference to the buffer
186 * @param pmask a bitmask containing the allowable permissions in the new
188 * @return a new reference to the buffer with the same properties as the
189 * old, excluding any permissions denied by pmask
191 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
194 * Remove a reference to a buffer. If this is the last reference to the
195 * buffer, the buffer itself is also automatically freed.
197 * @param ref reference to the buffer, may be NULL
199 void avfilter_unref_buffer(AVFilterBufferRef *ref);
201 #if FF_API_FILTERS_PUBLIC
203 * @addtogroup lavfi_deprecated
204 * @deprecated Those functions are only useful inside filters and
205 * user filters are not supported at this point.
208 struct AVFilterFormats {
209 unsigned format_count; ///< number of formats
210 int *formats; ///< list of media formats
212 unsigned refcount; ///< number of references to this list
213 struct AVFilterFormats ***refs; ///< references to this list
217 AVFilterFormats *avfilter_make_format_list(const int *fmts);
219 int avfilter_add_format(AVFilterFormats **avff, int fmt);
221 AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
223 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
225 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
227 void avfilter_formats_unref(AVFilterFormats **ref);
229 void avfilter_formats_changeref(AVFilterFormats **oldref,
230 AVFilterFormats **newref);
232 void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
238 #if FF_API_AVFILTERPAD_PUBLIC
240 * A filter pad used for either input or output.
242 * @warning this struct will be removed from public API.
243 * users should call avfilter_pad_get_name() and avfilter_pad_get_type()
244 * to access the name and type fields; there should be no need to access
245 * any other fields from outside of libavfilter.
249 * Pad name. The name is unique among inputs and among outputs, but an
250 * input may have the same name as an output. This may be NULL if this
251 * pad has no need to ever be referenced by name.
258 enum AVMediaType type;
261 * Minimum required permissions on incoming buffers. Any buffer with
262 * insufficient permissions will be automatically copied by the filter
263 * system to a new buffer which provides the needed access permissions.
270 * Permissions which are not accepted on incoming buffers. Any buffer
271 * which has any of these permissions set will be automatically copied
272 * by the filter system to a new buffer which does not have those
273 * permissions. This can be used to easily disallow buffers with
281 * Callback called before passing the first slice of a new frame. If
282 * NULL, the filter layer will default to storing a reference to the
283 * picture inside the link structure.
285 * Input video pads only.
287 void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
290 * Callback function to get a video buffer. If NULL, the filter system will
291 * use avfilter_default_get_video_buffer().
293 * Input video pads only.
295 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
298 * Callback function to get an audio buffer. If NULL, the filter system will
299 * use avfilter_default_get_audio_buffer().
301 * Input audio pads only.
303 AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms,
307 * Callback called after the slices of a frame are completely sent. If
308 * NULL, the filter layer will default to releasing the reference stored
309 * in the link structure during start_frame().
311 * Input video pads only.
313 void (*end_frame)(AVFilterLink *link);
316 * Slice drawing callback. This is where a filter receives video data
317 * and should do its processing.
319 * Input video pads only.
321 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
324 * Samples filtering callback. This is where a filter receives audio data
325 * and should do its processing.
327 * Input audio pads only.
329 void (*filter_samples)(AVFilterLink *link, AVFilterBufferRef *samplesref);
332 * Frame poll callback. This returns the number of immediately available
333 * samples. It should return a positive value if the next request_frame()
334 * is guaranteed to return one frame (with no delay).
336 * Defaults to just calling the source poll_frame() method.
340 int (*poll_frame)(AVFilterLink *link);
343 * Frame request callback. A call to this should result in at least one
344 * frame being output over the given link. This should return zero on
345 * success, and another value on error.
349 int (*request_frame)(AVFilterLink *link);
352 * Link configuration callback.
354 * For output pads, this should set the link properties such as
355 * width/height. This should NOT set the format property - that is
356 * negotiated between filters by the filter system using the
357 * query_formats() callback before this function is called.
359 * For input pads, this should check the properties of the link, and update
360 * the filter's internal state as necessary.
362 * For both input and output filters, this should return zero on success,
363 * and another value on error.
365 int (*config_props)(AVFilterLink *link);
370 * Get the name of an AVFilterPad.
372 * @param pads an array of AVFilterPads
373 * @param pad_idx index of the pad in the array it; is the caller's
374 * responsibility to ensure the index is valid
376 * @return name of the pad_idx'th pad in pads
378 const char *avfilter_pad_get_name(AVFilterPad *pads, int pad_idx);
381 * Get the type of an AVFilterPad.
383 * @param pads an array of AVFilterPads
384 * @param pad_idx index of the pad in the array; it is the caller's
385 * responsibility to ensure the index is valid
387 * @return type of the pad_idx'th pad in pads
389 enum AVMediaType avfilter_pad_get_type(AVFilterPad *pads, int pad_idx);
391 #if FF_API_FILTERS_PUBLIC
392 /** default handler for start_frame() for video inputs */
394 void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
396 /** default handler for draw_slice() for video inputs */
398 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
400 /** default handler for end_frame() for video inputs */
402 void avfilter_default_end_frame(AVFilterLink *link);
404 #if FF_API_DEFAULT_CONFIG_OUTPUT_LINK
405 /** default handler for config_props() for audio/video outputs */
407 int avfilter_default_config_output_link(AVFilterLink *link);
410 /** default handler for get_video_buffer() for video inputs */
412 AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,
413 int perms, int w, int h);
415 /** Default handler for query_formats() */
417 int avfilter_default_query_formats(AVFilterContext *ctx);
420 #if FF_API_FILTERS_PUBLIC
421 /** start_frame() handler for filters which simply pass video along */
423 void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
425 /** draw_slice() handler for filters which simply pass video along */
427 void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
429 /** end_frame() handler for filters which simply pass video along */
431 void avfilter_null_end_frame(AVFilterLink *link);
433 /** get_video_buffer() handler for filters which simply pass video along */
435 AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link,
436 int perms, int w, int h);
440 * Filter definition. This defines the pads a filter contains, and all the
441 * callback functions used to interact with the filter.
443 typedef struct AVFilter {
444 const char *name; ///< filter name
446 int priv_size; ///< size of private data to allocate for the filter
449 * Filter initialization function. Args contains the user-supplied
450 * parameters. FIXME: maybe an AVOption-based system would be better?
451 * opaque is data provided by the code requesting creation of the filter,
452 * and is used to pass data to the filter.
454 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
457 * Filter uninitialization function. Should deallocate any memory held
458 * by the filter, release any buffer references, etc. This does not need
459 * to deallocate the AVFilterContext->priv memory itself.
461 void (*uninit)(AVFilterContext *ctx);
464 * Queries formats supported by the filter and its pads, and sets the
465 * in_formats for links connected to its output pads, and out_formats
466 * for links connected to its input pads.
468 * @return zero on success, a negative value corresponding to an
469 * AVERROR code otherwise
471 int (*query_formats)(AVFilterContext *);
473 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
474 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
477 * A description for the filter. You should use the
478 * NULL_IF_CONFIG_SMALL() macro to define it.
480 const char *description;
483 /** An instance of a filter */
484 struct AVFilterContext {
485 const AVClass *av_class; ///< needed for av_log()
487 AVFilter *filter; ///< the AVFilter of which this is an instance
489 char *name; ///< name of this filter instance
492 unsigned input_count; ///< @deprecated use nb_inputs
494 AVFilterPad *input_pads; ///< array of input pads
495 AVFilterLink **inputs; ///< array of pointers to input links
498 unsigned output_count; ///< @deprecated use nb_outputs
500 AVFilterPad *output_pads; ///< array of output pads
501 AVFilterLink **outputs; ///< array of pointers to output links
503 void *priv; ///< private data for use by the filter
505 unsigned nb_inputs; ///< number of input pads
506 unsigned nb_outputs; ///< number of output pads
510 * A link between two filters. This contains pointers to the source and
511 * destination filters between which this link exists, and the indexes of
512 * the pads involved. In addition, this link also contains the parameters
513 * which have been negotiated and agreed upon between the filter, such as
514 * image dimensions, format, etc.
516 struct AVFilterLink {
517 AVFilterContext *src; ///< source filter
518 AVFilterPad *srcpad; ///< output pad on the source filter
520 AVFilterContext *dst; ///< dest filter
521 AVFilterPad *dstpad; ///< input pad on the dest filter
523 /** stage of the initialization of the link properties (dimensions, etc) */
525 AVLINK_UNINIT = 0, ///< not started
526 AVLINK_STARTINIT, ///< started, but incomplete
527 AVLINK_INIT ///< complete
530 enum AVMediaType type; ///< filter media type
532 /* These parameters apply only to video */
533 int w; ///< agreed upon image width
534 int h; ///< agreed upon image height
535 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
536 /* These two parameters apply only to audio */
537 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/audioconvert.h)
538 #if FF_API_SAMPLERATE64
539 int64_t sample_rate; ///< samples per second
541 int sample_rate; ///< samples per second
544 int format; ///< agreed upon media format
547 * Lists of formats supported by the input and output filters respectively.
548 * These lists are used for negotiating the format to actually be used,
549 * which will be loaded into the format member, above, when chosen.
551 AVFilterFormats *in_formats;
552 AVFilterFormats *out_formats;
555 * The buffer reference currently being sent across the link by the source
556 * filter. This is used internally by the filter system to allow
557 * automatic copying of buffers which do not have sufficient permissions
558 * for the destination. This should not be accessed directly by the
561 AVFilterBufferRef *src_buf;
563 AVFilterBufferRef *cur_buf;
564 AVFilterBufferRef *out_buf;
567 * Define the time base used by the PTS of the frames/samples
568 * which will pass through this link.
569 * During the configuration stage, each filter is supposed to
570 * change only the output timebase, while the timebase of the
571 * input link is assumed to be an unchangeable property.
573 AVRational time_base;
575 /*****************************************************************
576 * All fields below this line are not part of the public API. They
577 * may not be used outside of libavfilter and can be changed and
579 * New public fields should be added right above.
580 *****************************************************************
583 * Lists of channel layouts and sample rates used for automatic
586 AVFilterFormats *in_samplerates;
587 AVFilterFormats *out_samplerates;
588 struct AVFilterChannelLayouts *in_channel_layouts;
589 struct AVFilterChannelLayouts *out_channel_layouts;
593 * Link two filters together.
595 * @param src the source filter
596 * @param srcpad index of the output pad on the source filter
597 * @param dst the destination filter
598 * @param dstpad index of the input pad on the destination filter
599 * @return zero on success
601 int avfilter_link(AVFilterContext *src, unsigned srcpad,
602 AVFilterContext *dst, unsigned dstpad);
605 * Negotiate the media format, dimensions, etc of all inputs to a filter.
607 * @param filter the filter to negotiate the properties for its inputs
608 * @return zero on successful negotiation
610 int avfilter_config_links(AVFilterContext *filter);
612 #if FF_API_FILTERS_PUBLIC
614 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
619 * Create a buffer reference wrapped around an already allocated image
622 * @param data pointers to the planes of the image to reference
623 * @param linesize linesizes for the planes of the image to reference
624 * @param perms the required access permissions
625 * @param w the width of the image specified by the data and linesize arrays
626 * @param h the height of the image specified by the data and linesize arrays
627 * @param format the pixel format of the image specified by the data and linesize arrays
630 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
631 int w, int h, enum PixelFormat format);
634 * Create an audio buffer reference wrapped around an already
635 * allocated samples buffer.
637 * @param data pointers to the samples plane buffers
638 * @param linesize linesize for the samples plane buffers
639 * @param perms the required access permissions
640 * @param nb_samples number of samples per channel
641 * @param sample_fmt the format of each sample in the buffer to allocate
642 * @param channel_layout the channel layout of the buffer
644 AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays(uint8_t **data,
648 enum AVSampleFormat sample_fmt,
649 uint64_t channel_layout);
651 #if FF_API_FILTERS_PUBLIC
653 int avfilter_request_frame(AVFilterLink *link);
656 int avfilter_poll_frame(AVFilterLink *link);
659 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
661 void avfilter_end_frame(AVFilterLink *link);
663 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
666 /** Initialize the filter system. Register all builtin filters. */
667 void avfilter_register_all(void);
669 /** Uninitialize the filter system. Unregister all filters. */
670 void avfilter_uninit(void);
673 * Register a filter. This is only needed if you plan to use
674 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
675 * filter can still by instantiated with avfilter_open even if it is not
678 * @param filter the filter to register
679 * @return 0 if the registration was succesfull, a negative value
682 int avfilter_register(AVFilter *filter);
685 * Get a filter definition matching the given name.
687 * @param name the filter name to find
688 * @return the filter definition, if any matching one is registered.
689 * NULL if none found.
691 AVFilter *avfilter_get_by_name(const char *name);
694 * If filter is NULL, returns a pointer to the first registered filter pointer,
695 * if filter is non-NULL, returns the next pointer after filter.
696 * If the returned pointer points to NULL, the last registered filter
697 * was already reached.
699 AVFilter **av_filter_next(AVFilter **filter);
702 * Create a filter instance.
704 * @param filter_ctx put here a pointer to the created filter context
705 * on success, NULL on failure
706 * @param filter the filter to create an instance of
707 * @param inst_name Name to give to the new instance. Can be NULL for none.
708 * @return >= 0 in case of success, a negative error code otherwise
710 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
713 * Initialize a filter.
715 * @param filter the filter to initialize
716 * @param args A string of parameters to use when initializing the filter.
717 * The format and meaning of this string varies by filter.
718 * @param opaque Any extra non-string data needed by the filter. The meaning
719 * of this parameter varies by filter.
720 * @return zero on success
722 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
725 * Free a filter context.
727 * @param filter the filter to free
729 void avfilter_free(AVFilterContext *filter);
732 * Insert a filter in the middle of an existing link.
734 * @param link the link into which the filter should be inserted
735 * @param filt the filter to be inserted
736 * @param filt_srcpad_idx the input pad on the filter to connect
737 * @param filt_dstpad_idx the output pad on the filter to connect
738 * @return zero on success
740 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
741 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
743 #if FF_API_FILTERS_PUBLIC
745 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
746 AVFilterPad **pads, AVFilterLink ***links,
747 AVFilterPad *newpad);
750 void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
753 void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
758 * Copy the frame properties of src to dst, without copying the actual
761 * @return 0 on success, a negative number on error.
763 int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src);
766 * Copy the frame properties and data pointers of src to dst, without copying
769 * @return 0 on success, a negative number on error.
771 int avfilter_copy_buf_props(AVFrame *dst, const AVFilterBufferRef *src);
773 #endif /* AVFILTER_AVFILTER_H */