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
66 * pointers to the data planes/channels.
68 * For video, this should simply point to data[].
70 * For planar audio, each channel has a separate data pointer, and
71 * linesize[0] contains the size of each channel buffer.
72 * For packed audio, there is just one data pointer, and linesize[0]
73 * contains the total size of the buffer for all channels.
75 * Note: Both data and extended_data will always be set, but for planar
76 * audio with more channels that can fit in data, extended_data must be used
77 * in order to access all channels.
79 uint8_t **extended_data;
80 int linesize[8]; ///< number of bytes per line
82 /** private data to be used by a custom free function */
85 * A pointer to the function to deallocate this buffer if the default
86 * function is not sufficient. This could, for example, add the memory
87 * back into a memory pool to be reused later without the overhead of
88 * reallocating it from scratch.
90 void (*free)(struct AVFilterBuffer *buf);
92 int format; ///< media format
93 int w, h; ///< width and height of the allocated buffer
94 unsigned refcount; ///< number of references to this 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
105 * Audio specific properties in a reference to an AVFilterBuffer. Since
106 * AVFilterBufferRef is common to different media formats, audio specific
107 * per reference properties must be separated out.
109 typedef struct AVFilterBufferRefAudioProps {
110 uint64_t channel_layout; ///< channel layout of audio buffer
111 int nb_samples; ///< number of audio samples
112 int sample_rate; ///< audio buffer sample rate
113 int planar; ///< audio buffer - planar or packed
114 } AVFilterBufferRefAudioProps;
117 * Video specific properties in a reference to an AVFilterBuffer. Since
118 * AVFilterBufferRef is common to different media formats, video specific
119 * per reference properties must be separated out.
121 typedef struct AVFilterBufferRefVideoProps {
122 int w; ///< image width
123 int h; ///< image height
124 AVRational pixel_aspect; ///< pixel aspect ratio
125 int interlaced; ///< is frame interlaced
126 int top_field_first; ///< field order
127 enum AVPictureType pict_type; ///< picture type of the frame
128 int key_frame; ///< 1 -> keyframe, 0-> not
129 } AVFilterBufferRefVideoProps;
132 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
133 * a buffer to, for example, crop image without any memcpy, the buffer origin
134 * and dimensions are per-reference properties. Linesize is also useful for
135 * image flipping, frame to field filters, etc, and so is also per-reference.
137 * TODO: add anything necessary for frame reordering
139 typedef struct AVFilterBufferRef {
140 AVFilterBuffer *buf; ///< the buffer that this is a reference to
141 uint8_t *data[8]; ///< picture/audio data for each plane
143 * pointers to the data planes/channels.
145 * For video, this should simply point to data[].
147 * For planar audio, each channel has a separate data pointer, and
148 * linesize[0] contains the size of each channel buffer.
149 * For packed audio, there is just one data pointer, and linesize[0]
150 * contains the total size of the buffer for all channels.
152 * Note: Both data and extended_data will always be set, but for planar
153 * audio with more channels that can fit in data, extended_data must be used
154 * in order to access all channels.
156 uint8_t **extended_data;
157 int linesize[8]; ///< number of bytes per line
159 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
160 AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
163 * presentation timestamp. The time unit may change during
164 * filtering, as it is specified in the link and the filter code
165 * may need to rescale the PTS accordingly.
168 int64_t pos; ///< byte position in stream, -1 if unknown
170 int format; ///< media format
172 int perms; ///< permissions, see the AV_PERM_* flags
174 enum AVMediaType type; ///< media type of buffer 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_AVFILTERPAD_PUBLIC
203 * A filter pad used for either input or output.
205 * @warning this struct will be removed from public API.
206 * users should call avfilter_pad_get_name() and avfilter_pad_get_type()
207 * to access the name and type fields; there should be no need to access
208 * any other fields from outside of libavfilter.
212 * Pad name. The name is unique among inputs and among outputs, but an
213 * input may have the same name as an output. This may be NULL if this
214 * pad has no need to ever be referenced by name.
221 enum AVMediaType type;
224 * Minimum required permissions on incoming buffers. Any buffer with
225 * insufficient permissions will be automatically copied by the filter
226 * system to a new buffer which provides the needed access permissions.
233 * Permissions which are not accepted on incoming buffers. Any buffer
234 * which has any of these permissions set will be automatically copied
235 * by the filter system to a new buffer which does not have those
236 * permissions. This can be used to easily disallow buffers with
244 * Callback called before passing the first slice of a new frame. If
245 * NULL, the filter layer will default to storing a reference to the
246 * picture inside the link structure.
248 * Input video pads only.
250 void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
253 * Callback function to get a video buffer. If NULL, the filter system will
254 * use avfilter_default_get_video_buffer().
256 * Input video pads only.
258 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
261 * Callback function to get an audio buffer. If NULL, the filter system will
262 * use avfilter_default_get_audio_buffer().
264 * Input audio pads only.
266 AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms,
270 * Callback called after the slices of a frame are completely sent. If
271 * NULL, the filter layer will default to releasing the reference stored
272 * in the link structure during start_frame().
274 * Input video pads only.
276 void (*end_frame)(AVFilterLink *link);
279 * Slice drawing callback. This is where a filter receives video data
280 * and should do its processing.
282 * Input video pads only.
284 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
287 * Samples filtering callback. This is where a filter receives audio data
288 * and should do its processing.
290 * Input audio pads only.
292 * @return >= 0 on success, a negative AVERROR on error. This function
293 * must ensure that samplesref is properly unreferenced on error if it
294 * hasn't been passed on to another filter.
296 int (*filter_samples)(AVFilterLink *link, AVFilterBufferRef *samplesref);
299 * Frame poll callback. This returns the number of immediately available
300 * samples. It should return a positive value if the next request_frame()
301 * is guaranteed to return one frame (with no delay).
303 * Defaults to just calling the source poll_frame() method.
307 int (*poll_frame)(AVFilterLink *link);
310 * Frame request callback. A call to this should result in at least one
311 * frame being output over the given link. This should return zero on
312 * success, and another value on error.
316 int (*request_frame)(AVFilterLink *link);
319 * Link configuration callback.
321 * For output pads, this should set the link properties such as
322 * width/height. This should NOT set the format property - that is
323 * negotiated between filters by the filter system using the
324 * query_formats() callback before this function is called.
326 * For input pads, this should check the properties of the link, and update
327 * the filter's internal state as necessary.
329 * For both input and output filters, this should return zero on success,
330 * and another value on error.
332 int (*config_props)(AVFilterLink *link);
335 * The filter expects a fifo to be inserted on its input link,
336 * typically because it has a delay.
345 * Get the name of an AVFilterPad.
347 * @param pads an array of AVFilterPads
348 * @param pad_idx index of the pad in the array it; is the caller's
349 * responsibility to ensure the index is valid
351 * @return name of the pad_idx'th pad in pads
353 const char *avfilter_pad_get_name(AVFilterPad *pads, int pad_idx);
356 * Get the type of an AVFilterPad.
358 * @param pads an array of AVFilterPads
359 * @param pad_idx index of the pad in the array; it is the caller's
360 * responsibility to ensure the index is valid
362 * @return type of the pad_idx'th pad in pads
364 enum AVMediaType avfilter_pad_get_type(AVFilterPad *pads, int pad_idx);
367 * Filter definition. This defines the pads a filter contains, and all the
368 * callback functions used to interact with the filter.
370 typedef struct AVFilter {
371 const char *name; ///< filter name
374 * A description for the filter. You should use the
375 * NULL_IF_CONFIG_SMALL() macro to define it.
377 const char *description;
379 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
380 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
382 /*****************************************************************
383 * All fields below this line are not part of the public API. They
384 * may not be used outside of libavfilter and can be changed and
386 * New public fields should be added right above.
387 *****************************************************************
391 * Filter initialization function. Args contains the user-supplied
392 * parameters. FIXME: maybe an AVOption-based system would be better?
394 int (*init)(AVFilterContext *ctx, const char *args);
397 * Filter uninitialization function. Should deallocate any memory held
398 * by the filter, release any buffer references, etc. This does not need
399 * to deallocate the AVFilterContext->priv memory itself.
401 void (*uninit)(AVFilterContext *ctx);
404 * Queries formats supported by the filter and its pads, and sets the
405 * in_formats for links connected to its output pads, and out_formats
406 * for links connected to its input pads.
408 * @return zero on success, a negative value corresponding to an
409 * AVERROR code otherwise
411 int (*query_formats)(AVFilterContext *);
413 int priv_size; ///< size of private data to allocate for the filter
416 /** An instance of a filter */
417 struct AVFilterContext {
418 const AVClass *av_class; ///< needed for av_log()
420 AVFilter *filter; ///< the AVFilter of which this is an instance
422 char *name; ///< name of this filter instance
424 AVFilterPad *input_pads; ///< array of input pads
425 AVFilterLink **inputs; ///< array of pointers to input links
427 unsigned input_count; ///< @deprecated use nb_inputs
429 unsigned nb_inputs; ///< number of input pads
431 AVFilterPad *output_pads; ///< array of output pads
432 AVFilterLink **outputs; ///< array of pointers to output links
434 unsigned output_count; ///< @deprecated use nb_outputs
436 unsigned nb_outputs; ///< number of output pads
438 void *priv; ///< private data for use by the filter
442 * A link between two filters. This contains pointers to the source and
443 * destination filters between which this link exists, and the indexes of
444 * the pads involved. In addition, this link also contains the parameters
445 * which have been negotiated and agreed upon between the filter, such as
446 * image dimensions, format, etc.
448 struct AVFilterLink {
449 AVFilterContext *src; ///< source filter
450 AVFilterPad *srcpad; ///< output pad on the source filter
452 AVFilterContext *dst; ///< dest filter
453 AVFilterPad *dstpad; ///< input pad on the dest filter
455 enum AVMediaType type; ///< filter media type
457 /* These parameters apply only to video */
458 int w; ///< agreed upon image width
459 int h; ///< agreed upon image height
460 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
461 /* These two parameters apply only to audio */
462 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/audioconvert.h)
463 int sample_rate; ///< samples per second
465 int format; ///< agreed upon media format
468 * Define the time base used by the PTS of the frames/samples
469 * which will pass through this link.
470 * During the configuration stage, each filter is supposed to
471 * change only the output timebase, while the timebase of the
472 * input link is assumed to be an unchangeable property.
474 AVRational time_base;
476 /*****************************************************************
477 * All fields below this line are not part of the public API. They
478 * may not be used outside of libavfilter and can be changed and
480 * New public fields should be added right above.
481 *****************************************************************
484 * Lists of formats supported by the input and output filters respectively.
485 * These lists are used for negotiating the format to actually be used,
486 * which will be loaded into the format member, above, when chosen.
488 AVFilterFormats *in_formats;
489 AVFilterFormats *out_formats;
492 * Lists of channel layouts and sample rates used for automatic
495 AVFilterFormats *in_samplerates;
496 AVFilterFormats *out_samplerates;
497 struct AVFilterChannelLayouts *in_channel_layouts;
498 struct AVFilterChannelLayouts *out_channel_layouts;
501 * Audio only, the destination filter sets this to a non-zero value to
502 * request that buffers with the given number of samples should be sent to
503 * it. AVFilterPad.needs_fifo must also be set on the corresponding input
505 * Last buffer before EOF will be padded with silence.
509 /** stage of the initialization of the link properties (dimensions, etc) */
511 AVLINK_UNINIT = 0, ///< not started
512 AVLINK_STARTINIT, ///< started, but incomplete
513 AVLINK_INIT ///< complete
517 * The buffer reference currently being sent across the link by the source
518 * filter. This is used internally by the filter system to allow
519 * automatic copying of buffers which do not have sufficient permissions
520 * for the destination. This should not be accessed directly by the
523 AVFilterBufferRef *src_buf;
525 AVFilterBufferRef *cur_buf;
526 AVFilterBufferRef *out_buf;
530 * Link two filters together.
532 * @param src the source filter
533 * @param srcpad index of the output pad on the source filter
534 * @param dst the destination filter
535 * @param dstpad index of the input pad on the destination filter
536 * @return zero on success
538 int avfilter_link(AVFilterContext *src, unsigned srcpad,
539 AVFilterContext *dst, unsigned dstpad);
542 * Negotiate the media format, dimensions, etc of all inputs to a filter.
544 * @param filter the filter to negotiate the properties for its inputs
545 * @return zero on successful negotiation
547 int avfilter_config_links(AVFilterContext *filter);
550 * Create a buffer reference wrapped around an already allocated image
553 * @param data pointers to the planes of the image to reference
554 * @param linesize linesizes for the planes of the image to reference
555 * @param perms the required access permissions
556 * @param w the width of the image specified by the data and linesize arrays
557 * @param h the height of the image specified by the data and linesize arrays
558 * @param format the pixel format of the image specified by the data and linesize arrays
561 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
562 int w, int h, enum PixelFormat format);
565 * Create an audio buffer reference wrapped around an already
566 * allocated samples buffer.
568 * @param data pointers to the samples plane buffers
569 * @param linesize linesize for the samples plane buffers
570 * @param perms the required access permissions
571 * @param nb_samples number of samples per channel
572 * @param sample_fmt the format of each sample in the buffer to allocate
573 * @param channel_layout the channel layout of the buffer
575 AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays(uint8_t **data,
579 enum AVSampleFormat sample_fmt,
580 uint64_t channel_layout);
582 /** Initialize the filter system. Register all builtin filters. */
583 void avfilter_register_all(void);
585 /** Uninitialize the filter system. Unregister all filters. */
586 void avfilter_uninit(void);
589 * Register a filter. This is only needed if you plan to use
590 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
591 * filter can still by instantiated with avfilter_open even if it is not
594 * @param filter the filter to register
595 * @return 0 if the registration was succesfull, a negative value
598 int avfilter_register(AVFilter *filter);
601 * Get a filter definition matching the given name.
603 * @param name the filter name to find
604 * @return the filter definition, if any matching one is registered.
605 * NULL if none found.
607 AVFilter *avfilter_get_by_name(const char *name);
610 * If filter is NULL, returns a pointer to the first registered filter pointer,
611 * if filter is non-NULL, returns the next pointer after filter.
612 * If the returned pointer points to NULL, the last registered filter
613 * was already reached.
615 AVFilter **av_filter_next(AVFilter **filter);
618 * Create a filter instance.
620 * @param filter_ctx put here a pointer to the created filter context
621 * on success, NULL on failure
622 * @param filter the filter to create an instance of
623 * @param inst_name Name to give to the new instance. Can be NULL for none.
624 * @return >= 0 in case of success, a negative error code otherwise
626 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
629 * Initialize a filter.
631 * @param filter the filter to initialize
632 * @param args A string of parameters to use when initializing the filter.
633 * The format and meaning of this string varies by filter.
634 * @param opaque Any extra non-string data needed by the filter. The meaning
635 * of this parameter varies by filter.
636 * @return zero on success
638 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
641 * Free a filter context.
643 * @param filter the filter to free
645 void avfilter_free(AVFilterContext *filter);
648 * Insert a filter in the middle of an existing link.
650 * @param link the link into which the filter should be inserted
651 * @param filt the filter to be inserted
652 * @param filt_srcpad_idx the input pad on the filter to connect
653 * @param filt_dstpad_idx the output pad on the filter to connect
654 * @return zero on success
656 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
657 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
660 * Copy the frame properties of src to dst, without copying the actual
663 * @return 0 on success, a negative number on error.
665 int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src);
668 * Copy the frame properties and data pointers of src to dst, without copying
671 * @return 0 on success, a negative number on error.
673 int avfilter_copy_buf_props(AVFrame *dst, const AVFilterBufferRef *src);
675 #endif /* AVFILTER_AVFILTER_H */