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/frame.h"
27 #include "libavutil/log.h"
28 #include "libavutil/samplefmt.h"
29 #include "libavutil/pixfmt.h"
30 #include "libavutil/rational.h"
31 #include "libavcodec/avcodec.h"
35 #include "libavfilter/version.h"
38 * Return the LIBAVFILTER_VERSION_INT constant.
40 unsigned avfilter_version(void);
43 * Return the libavfilter build-time configuration.
45 const char *avfilter_configuration(void);
48 * Return the libavfilter license.
50 const char *avfilter_license(void);
53 typedef struct AVFilterContext AVFilterContext;
54 typedef struct AVFilterLink AVFilterLink;
55 typedef struct AVFilterPad AVFilterPad;
56 typedef struct AVFilterFormats AVFilterFormats;
58 #if FF_API_AVFILTERBUFFER
60 * A reference-counted buffer data type used by the filter system. Filters
61 * should not store pointers to this structure directly, but instead use the
62 * AVFilterBufferRef structure below.
64 typedef struct AVFilterBuffer {
65 uint8_t *data[8]; ///< buffer data for each plane/channel
68 * pointers to the data planes/channels.
70 * For video, this should simply point to data[].
72 * For planar audio, each channel has a separate data pointer, and
73 * linesize[0] contains the size of each channel buffer.
74 * For packed audio, there is just one data pointer, and linesize[0]
75 * contains the total size of the buffer for all channels.
77 * Note: Both data and extended_data will always be set, but for planar
78 * audio with more channels that can fit in data, extended_data must be used
79 * in order to access all channels.
81 uint8_t **extended_data;
82 int linesize[8]; ///< number of bytes per line
84 /** private data to be used by a custom free function */
87 * A pointer to the function to deallocate this buffer if the default
88 * function is not sufficient. This could, for example, add the memory
89 * back into a memory pool to be reused later without the overhead of
90 * reallocating it from scratch.
92 void (*free)(struct AVFilterBuffer *buf);
94 int format; ///< media format
95 int w, h; ///< width and height of the allocated buffer
96 unsigned refcount; ///< number of references to this buffer
99 #define AV_PERM_READ 0x01 ///< can read from the buffer
100 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
101 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
102 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
103 #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
104 #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
107 * Audio specific properties in a reference to an AVFilterBuffer. Since
108 * AVFilterBufferRef is common to different media formats, audio specific
109 * per reference properties must be separated out.
111 typedef struct AVFilterBufferRefAudioProps {
112 uint64_t channel_layout; ///< channel layout of audio buffer
113 int nb_samples; ///< number of audio samples
114 int sample_rate; ///< audio buffer sample rate
115 int planar; ///< audio buffer - planar or packed
116 } AVFilterBufferRefAudioProps;
119 * Video specific properties in a reference to an AVFilterBuffer. Since
120 * AVFilterBufferRef is common to different media formats, video specific
121 * per reference properties must be separated out.
123 typedef struct AVFilterBufferRefVideoProps {
124 int w; ///< image width
125 int h; ///< image height
126 AVRational pixel_aspect; ///< pixel aspect ratio
127 int interlaced; ///< is frame interlaced
128 int top_field_first; ///< field order
129 enum AVPictureType pict_type; ///< picture type of the frame
130 int key_frame; ///< 1 -> keyframe, 0-> not
131 } AVFilterBufferRefVideoProps;
134 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
135 * a buffer to, for example, crop image without any memcpy, the buffer origin
136 * and dimensions are per-reference properties. Linesize is also useful for
137 * image flipping, frame to field filters, etc, and so is also per-reference.
139 * TODO: add anything necessary for frame reordering
141 typedef struct AVFilterBufferRef {
142 AVFilterBuffer *buf; ///< the buffer that this is a reference to
143 uint8_t *data[8]; ///< picture/audio data for each plane
145 * pointers to the data planes/channels.
147 * For video, this should simply point to data[].
149 * For planar audio, each channel has a separate data pointer, and
150 * linesize[0] contains the size of each channel buffer.
151 * For packed audio, there is just one data pointer, and linesize[0]
152 * contains the total size of the buffer for all channels.
154 * Note: Both data and extended_data will always be set, but for planar
155 * audio with more channels that can fit in data, extended_data must be used
156 * in order to access all channels.
158 uint8_t **extended_data;
159 int linesize[8]; ///< number of bytes per line
161 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
162 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
165 * presentation timestamp. The time unit may change during
166 * filtering, as it is specified in the link and the filter code
167 * may need to rescale the PTS accordingly.
170 int64_t pos; ///< byte position in stream, -1 if unknown
172 int format; ///< media format
174 int perms; ///< permissions, see the AV_PERM_* flags
176 enum AVMediaType type; ///< media type of buffer data
180 * Copy properties of src to dst, without copying the actual data
183 void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src);
186 * Add a new reference to a buffer.
188 * @param ref an existing reference to the buffer
189 * @param pmask a bitmask containing the allowable permissions in the new
191 * @return a new reference to the buffer with the same properties as the
192 * old, excluding any permissions denied by pmask
195 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
198 * Remove a reference to a buffer. If this is the last reference to the
199 * buffer, the buffer itself is also automatically freed.
201 * @param ref reference to the buffer, may be NULL
203 * @note it is recommended to use avfilter_unref_bufferp() instead of this
207 void avfilter_unref_buffer(AVFilterBufferRef *ref);
210 * Remove a reference to a buffer and set the pointer to NULL.
211 * If this is the last reference to the buffer, the buffer itself
212 * is also automatically freed.
214 * @param ref pointer to the buffer reference
217 void avfilter_unref_bufferp(AVFilterBufferRef **ref);
220 #if FF_API_AVFILTERPAD_PUBLIC
222 * A filter pad used for either input or output.
224 * @warning this struct will be removed from public API.
225 * users should call avfilter_pad_get_name() and avfilter_pad_get_type()
226 * to access the name and type fields; there should be no need to access
227 * any other fields from outside of libavfilter.
231 * Pad name. The name is unique among inputs and among outputs, but an
232 * input may have the same name as an output. This may be NULL if this
233 * pad has no need to ever be referenced by name.
240 enum AVMediaType type;
243 * Minimum required permissions on incoming buffers. Any buffer with
244 * insufficient permissions will be automatically copied by the filter
245 * system to a new buffer which provides the needed access permissions.
249 attribute_deprecated int min_perms;
252 * Permissions which are not accepted on incoming buffers. Any buffer
253 * which has any of these permissions set will be automatically copied
254 * by the filter system to a new buffer which does not have those
255 * permissions. This can be used to easily disallow buffers with
260 attribute_deprecated int rej_perms;
265 int (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
268 * Callback function to get a video buffer. If NULL, the filter system will
269 * use avfilter_default_get_video_buffer().
271 * Input video pads only.
273 AVFrame *(*get_video_buffer)(AVFilterLink *link, int w, int h);
276 * Callback function to get an audio buffer. If NULL, the filter system will
277 * use avfilter_default_get_audio_buffer().
279 * Input audio pads only.
281 AVFrame *(*get_audio_buffer)(AVFilterLink *link, int nb_samples);
286 int (*end_frame)(AVFilterLink *link);
291 int (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
294 * Filtering callback. This is where a filter receives a frame with
295 * audio/video data and should do its processing.
299 * @return >= 0 on success, a negative AVERROR on error. This function
300 * must ensure that samplesref is properly unreferenced on error if it
301 * hasn't been passed on to another filter.
303 int (*filter_frame)(AVFilterLink *link, AVFrame *frame);
306 * Frame poll callback. This returns the number of immediately available
307 * samples. It should return a positive value if the next request_frame()
308 * is guaranteed to return one frame (with no delay).
310 * Defaults to just calling the source poll_frame() method.
314 int (*poll_frame)(AVFilterLink *link);
317 * Frame request callback. A call to this should result in at least one
318 * frame being output over the given link. This should return zero on
319 * success, and another value on error.
323 int (*request_frame)(AVFilterLink *link);
326 * Link configuration callback.
328 * For output pads, this should set the link properties such as
329 * width/height. This should NOT set the format property - that is
330 * negotiated between filters by the filter system using the
331 * query_formats() callback before this function is called.
333 * For input pads, this should check the properties of the link, and update
334 * the filter's internal state as necessary.
336 * For both input and output filters, this should return zero on success,
337 * and another value on error.
339 int (*config_props)(AVFilterLink *link);
342 * The filter expects a fifo to be inserted on its input link,
343 * typically because it has a delay.
354 * Get the name of an AVFilterPad.
356 * @param pads an array of AVFilterPads
357 * @param pad_idx index of the pad in the array it; is the caller's
358 * responsibility to ensure the index is valid
360 * @return name of the pad_idx'th pad in pads
362 const char *avfilter_pad_get_name(AVFilterPad *pads, int pad_idx);
365 * Get the type of an AVFilterPad.
367 * @param pads an array of AVFilterPads
368 * @param pad_idx index of the pad in the array; it is the caller's
369 * responsibility to ensure the index is valid
371 * @return type of the pad_idx'th pad in pads
373 enum AVMediaType avfilter_pad_get_type(AVFilterPad *pads, int pad_idx);
376 * Filter definition. This defines the pads a filter contains, and all the
377 * callback functions used to interact with the filter.
379 typedef struct AVFilter {
380 const char *name; ///< filter name
383 * A description for the filter. You should use the
384 * NULL_IF_CONFIG_SMALL() macro to define it.
386 const char *description;
388 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
389 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
392 * A class for the private data, used to access filter private
395 const AVClass *priv_class;
397 /*****************************************************************
398 * All fields below this line are not part of the public API. They
399 * may not be used outside of libavfilter and can be changed and
401 * New public fields should be added right above.
402 *****************************************************************
406 * Filter initialization function. Args contains the user-supplied
407 * parameters. FIXME: maybe an AVOption-based system would be better?
409 int (*init)(AVFilterContext *ctx, const char *args);
412 * Should be set instead of init by the filters that want to pass a
413 * dictionary of AVOptions to nested contexts that are allocated in
416 int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
419 * Filter uninitialization function. Should deallocate any memory held
420 * by the filter, release any buffer references, etc. This does not need
421 * to deallocate the AVFilterContext->priv memory itself.
423 void (*uninit)(AVFilterContext *ctx);
426 * Queries formats supported by the filter and its pads, and sets the
427 * in_formats for links connected to its output pads, and out_formats
428 * for links connected to its input pads.
430 * @return zero on success, a negative value corresponding to an
431 * AVERROR code otherwise
433 int (*query_formats)(AVFilterContext *);
435 int priv_size; ///< size of private data to allocate for the filter
438 /** An instance of a filter */
439 struct AVFilterContext {
440 const AVClass *av_class; ///< needed for av_log()
442 AVFilter *filter; ///< the AVFilter of which this is an instance
444 char *name; ///< name of this filter instance
446 AVFilterPad *input_pads; ///< array of input pads
447 AVFilterLink **inputs; ///< array of pointers to input links
449 unsigned input_count; ///< @deprecated use nb_inputs
451 unsigned nb_inputs; ///< number of input pads
453 AVFilterPad *output_pads; ///< array of output pads
454 AVFilterLink **outputs; ///< array of pointers to output links
456 unsigned output_count; ///< @deprecated use nb_outputs
458 unsigned nb_outputs; ///< number of output pads
460 void *priv; ///< private data for use by the filter
464 * A link between two filters. This contains pointers to the source and
465 * destination filters between which this link exists, and the indexes of
466 * the pads involved. In addition, this link also contains the parameters
467 * which have been negotiated and agreed upon between the filter, such as
468 * image dimensions, format, etc.
470 struct AVFilterLink {
471 AVFilterContext *src; ///< source filter
472 AVFilterPad *srcpad; ///< output pad on the source filter
474 AVFilterContext *dst; ///< dest filter
475 AVFilterPad *dstpad; ///< input pad on the dest filter
477 enum AVMediaType type; ///< filter media type
479 /* These parameters apply only to video */
480 int w; ///< agreed upon image width
481 int h; ///< agreed upon image height
482 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
483 /* These two parameters apply only to audio */
484 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
485 int sample_rate; ///< samples per second
487 int format; ///< agreed upon media format
490 * Define the time base used by the PTS of the frames/samples
491 * which will pass through this link.
492 * During the configuration stage, each filter is supposed to
493 * change only the output timebase, while the timebase of the
494 * input link is assumed to be an unchangeable property.
496 AVRational time_base;
498 /*****************************************************************
499 * All fields below this line are not part of the public API. They
500 * may not be used outside of libavfilter and can be changed and
502 * New public fields should be added right above.
503 *****************************************************************
506 * Lists of formats supported by the input and output filters respectively.
507 * These lists are used for negotiating the format to actually be used,
508 * which will be loaded into the format member, above, when chosen.
510 AVFilterFormats *in_formats;
511 AVFilterFormats *out_formats;
514 * Lists of channel layouts and sample rates used for automatic
517 AVFilterFormats *in_samplerates;
518 AVFilterFormats *out_samplerates;
519 struct AVFilterChannelLayouts *in_channel_layouts;
520 struct AVFilterChannelLayouts *out_channel_layouts;
523 * Audio only, the destination filter sets this to a non-zero value to
524 * request that buffers with the given number of samples should be sent to
525 * it. AVFilterPad.needs_fifo must also be set on the corresponding input
527 * Last buffer before EOF will be padded with silence.
531 /** stage of the initialization of the link properties (dimensions, etc) */
533 AVLINK_UNINIT = 0, ///< not started
534 AVLINK_STARTINIT, ///< started, but incomplete
535 AVLINK_INIT ///< complete
540 * Link two filters together.
542 * @param src the source filter
543 * @param srcpad index of the output pad on the source filter
544 * @param dst the destination filter
545 * @param dstpad index of the input pad on the destination filter
546 * @return zero on success
548 int avfilter_link(AVFilterContext *src, unsigned srcpad,
549 AVFilterContext *dst, unsigned dstpad);
552 * Negotiate the media format, dimensions, etc of all inputs to a filter.
554 * @param filter the filter to negotiate the properties for its inputs
555 * @return zero on successful negotiation
557 int avfilter_config_links(AVFilterContext *filter);
559 #if FF_API_AVFILTERBUFFER
561 * Create a buffer reference wrapped around an already allocated image
564 * @param data pointers to the planes of the image to reference
565 * @param linesize linesizes for the planes of the image to reference
566 * @param perms the required access permissions
567 * @param w the width of the image specified by the data and linesize arrays
568 * @param h the height of the image specified by the data and linesize arrays
569 * @param format the pixel format of the image specified by the data and linesize arrays
573 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
574 int w, int h, enum AVPixelFormat format);
577 * Create an audio buffer reference wrapped around an already
578 * allocated samples buffer.
580 * @param data pointers to the samples plane buffers
581 * @param linesize linesize for the samples plane buffers
582 * @param perms the required access permissions
583 * @param nb_samples number of samples per channel
584 * @param sample_fmt the format of each sample in the buffer to allocate
585 * @param channel_layout the channel layout of the buffer
588 AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays(uint8_t **data,
592 enum AVSampleFormat sample_fmt,
593 uint64_t channel_layout);
596 /** Initialize the filter system. Register all builtin filters. */
597 void avfilter_register_all(void);
599 /** Uninitialize the filter system. Unregister all filters. */
600 void avfilter_uninit(void);
603 * Register a filter. This is only needed if you plan to use
604 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
605 * filter can still by instantiated with avfilter_open even if it is not
608 * @param filter the filter to register
609 * @return 0 if the registration was succesfull, a negative value
612 int avfilter_register(AVFilter *filter);
615 * Get a filter definition matching the given name.
617 * @param name the filter name to find
618 * @return the filter definition, if any matching one is registered.
619 * NULL if none found.
621 AVFilter *avfilter_get_by_name(const char *name);
624 * If filter is NULL, returns a pointer to the first registered filter pointer,
625 * if filter is non-NULL, returns the next pointer after filter.
626 * If the returned pointer points to NULL, the last registered filter
627 * was already reached.
629 AVFilter **av_filter_next(AVFilter **filter);
632 * Create a filter instance.
634 * @param filter_ctx put here a pointer to the created filter context
635 * on success, NULL on failure
636 * @param filter the filter to create an instance of
637 * @param inst_name Name to give to the new instance. Can be NULL for none.
638 * @return >= 0 in case of success, a negative error code otherwise
640 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
643 * Initialize a filter.
645 * @param filter the filter to initialize
646 * @param args A string of parameters to use when initializing the filter.
647 * The format and meaning of this string varies by filter.
648 * @param opaque Any extra non-string data needed by the filter. The meaning
649 * of this parameter varies by filter.
650 * @return zero on success
652 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
655 * Free a filter context.
657 * @param filter the filter to free
659 void avfilter_free(AVFilterContext *filter);
662 * Insert a filter in the middle of an existing link.
664 * @param link the link into which the filter should be inserted
665 * @param filt the filter to be inserted
666 * @param filt_srcpad_idx the input pad on the filter to connect
667 * @param filt_dstpad_idx the output pad on the filter to connect
668 * @return zero on success
670 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
671 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
673 #if FF_API_AVFILTERBUFFER
675 * Copy the frame properties of src to dst, without copying the actual
678 * @return 0 on success, a negative number on error.
681 int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src);
684 * Copy the frame properties and data pointers of src to dst, without copying
687 * @return 0 on success, a negative number on error.
690 int avfilter_copy_buf_props(AVFrame *dst, const AVFilterBufferRef *src);
693 #endif /* AVFILTER_AVFILTER_H */