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 * @note it is recommended to use avfilter_unref_bufferp() instead of this
202 void avfilter_unref_buffer(AVFilterBufferRef *ref);
205 * Remove a reference to a buffer and set the pointer to NULL.
206 * If this is the last reference to the buffer, the buffer itself
207 * is also automatically freed.
209 * @param ref pointer to the buffer reference
211 void avfilter_unref_bufferp(AVFilterBufferRef **ref);
213 #if FF_API_AVFILTERPAD_PUBLIC
215 * A filter pad used for either input or output.
217 * @warning this struct will be removed from public API.
218 * users should call avfilter_pad_get_name() and avfilter_pad_get_type()
219 * to access the name and type fields; there should be no need to access
220 * any other fields from outside of libavfilter.
224 * Pad name. The name is unique among inputs and among outputs, but an
225 * input may have the same name as an output. This may be NULL if this
226 * pad has no need to ever be referenced by name.
233 enum AVMediaType type;
236 * Minimum required permissions on incoming buffers. Any buffer with
237 * insufficient permissions will be automatically copied by the filter
238 * system to a new buffer which provides the needed access permissions.
245 * Permissions which are not accepted on incoming buffers. Any buffer
246 * which has any of these permissions set will be automatically copied
247 * by the filter system to a new buffer which does not have those
248 * permissions. This can be used to easily disallow buffers with
258 int (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
261 * Callback function to get a video buffer. If NULL, the filter system will
262 * use avfilter_default_get_video_buffer().
264 * Input video pads only.
266 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
269 * Callback function to get an audio buffer. If NULL, the filter system will
270 * use avfilter_default_get_audio_buffer().
272 * Input audio pads only.
274 AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms,
280 int (*end_frame)(AVFilterLink *link);
285 int (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
288 * Filtering callback. This is where a filter receives a frame with
289 * audio/video data and should do its processing.
293 * @return >= 0 on success, a negative AVERROR on error. This function
294 * must ensure that samplesref is properly unreferenced on error if it
295 * hasn't been passed on to another filter.
297 int (*filter_frame)(AVFilterLink *link, AVFilterBufferRef *frame);
300 * Frame poll callback. This returns the number of immediately available
301 * samples. It should return a positive value if the next request_frame()
302 * is guaranteed to return one frame (with no delay).
304 * Defaults to just calling the source poll_frame() method.
308 int (*poll_frame)(AVFilterLink *link);
311 * Frame request callback. A call to this should result in at least one
312 * frame being output over the given link. This should return zero on
313 * success, and another value on error.
317 int (*request_frame)(AVFilterLink *link);
320 * Link configuration callback.
322 * For output pads, this should set the link properties such as
323 * width/height. This should NOT set the format property - that is
324 * negotiated between filters by the filter system using the
325 * query_formats() callback before this function is called.
327 * For input pads, this should check the properties of the link, and update
328 * the filter's internal state as necessary.
330 * For both input and output filters, this should return zero on success,
331 * and another value on error.
333 int (*config_props)(AVFilterLink *link);
336 * The filter expects a fifo to be inserted on its input link,
337 * typically because it has a delay.
346 * Get the name of an AVFilterPad.
348 * @param pads an array of AVFilterPads
349 * @param pad_idx index of the pad in the array it; is the caller's
350 * responsibility to ensure the index is valid
352 * @return name of the pad_idx'th pad in pads
354 const char *avfilter_pad_get_name(AVFilterPad *pads, int pad_idx);
357 * Get the type of an AVFilterPad.
359 * @param pads an array of AVFilterPads
360 * @param pad_idx index of the pad in the array; it is the caller's
361 * responsibility to ensure the index is valid
363 * @return type of the pad_idx'th pad in pads
365 enum AVMediaType avfilter_pad_get_type(AVFilterPad *pads, int pad_idx);
368 * Filter definition. This defines the pads a filter contains, and all the
369 * callback functions used to interact with the filter.
371 typedef struct AVFilter {
372 const char *name; ///< filter name
375 * A description for the filter. You should use the
376 * NULL_IF_CONFIG_SMALL() macro to define it.
378 const char *description;
380 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
381 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
383 /*****************************************************************
384 * All fields below this line are not part of the public API. They
385 * may not be used outside of libavfilter and can be changed and
387 * New public fields should be added right above.
388 *****************************************************************
392 * Filter initialization function. Args contains the user-supplied
393 * parameters. FIXME: maybe an AVOption-based system would be better?
395 int (*init)(AVFilterContext *ctx, const char *args);
398 * Filter uninitialization function. Should deallocate any memory held
399 * by the filter, release any buffer references, etc. This does not need
400 * to deallocate the AVFilterContext->priv memory itself.
402 void (*uninit)(AVFilterContext *ctx);
405 * Queries formats supported by the filter and its pads, and sets the
406 * in_formats for links connected to its output pads, and out_formats
407 * for links connected to its input pads.
409 * @return zero on success, a negative value corresponding to an
410 * AVERROR code otherwise
412 int (*query_formats)(AVFilterContext *);
414 int priv_size; ///< size of private data to allocate for the filter
417 /** An instance of a filter */
418 struct AVFilterContext {
419 const AVClass *av_class; ///< needed for av_log()
421 AVFilter *filter; ///< the AVFilter of which this is an instance
423 char *name; ///< name of this filter instance
425 AVFilterPad *input_pads; ///< array of input pads
426 AVFilterLink **inputs; ///< array of pointers to input links
428 unsigned input_count; ///< @deprecated use nb_inputs
430 unsigned nb_inputs; ///< number of input pads
432 AVFilterPad *output_pads; ///< array of output pads
433 AVFilterLink **outputs; ///< array of pointers to output links
435 unsigned output_count; ///< @deprecated use nb_outputs
437 unsigned nb_outputs; ///< number of output pads
439 void *priv; ///< private data for use by the filter
443 * A link between two filters. This contains pointers to the source and
444 * destination filters between which this link exists, and the indexes of
445 * the pads involved. In addition, this link also contains the parameters
446 * which have been negotiated and agreed upon between the filter, such as
447 * image dimensions, format, etc.
449 struct AVFilterLink {
450 AVFilterContext *src; ///< source filter
451 AVFilterPad *srcpad; ///< output pad on the source filter
453 AVFilterContext *dst; ///< dest filter
454 AVFilterPad *dstpad; ///< input pad on the dest filter
456 enum AVMediaType type; ///< filter media type
458 /* These parameters apply only to video */
459 int w; ///< agreed upon image width
460 int h; ///< agreed upon image height
461 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
462 /* These two parameters apply only to audio */
463 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
464 int sample_rate; ///< samples per second
466 int format; ///< agreed upon media format
469 * Define the time base used by the PTS of the frames/samples
470 * which will pass through this link.
471 * During the configuration stage, each filter is supposed to
472 * change only the output timebase, while the timebase of the
473 * input link is assumed to be an unchangeable property.
475 AVRational time_base;
477 /*****************************************************************
478 * All fields below this line are not part of the public API. They
479 * may not be used outside of libavfilter and can be changed and
481 * New public fields should be added right above.
482 *****************************************************************
485 * Lists of formats supported by the input and output filters respectively.
486 * These lists are used for negotiating the format to actually be used,
487 * which will be loaded into the format member, above, when chosen.
489 AVFilterFormats *in_formats;
490 AVFilterFormats *out_formats;
493 * Lists of channel layouts and sample rates used for automatic
496 AVFilterFormats *in_samplerates;
497 AVFilterFormats *out_samplerates;
498 struct AVFilterChannelLayouts *in_channel_layouts;
499 struct AVFilterChannelLayouts *out_channel_layouts;
502 * Audio only, the destination filter sets this to a non-zero value to
503 * request that buffers with the given number of samples should be sent to
504 * it. AVFilterPad.needs_fifo must also be set on the corresponding input
506 * Last buffer before EOF will be padded with silence.
510 /** stage of the initialization of the link properties (dimensions, etc) */
512 AVLINK_UNINIT = 0, ///< not started
513 AVLINK_STARTINIT, ///< started, but incomplete
514 AVLINK_INIT ///< complete
519 * Link two filters together.
521 * @param src the source filter
522 * @param srcpad index of the output pad on the source filter
523 * @param dst the destination filter
524 * @param dstpad index of the input pad on the destination filter
525 * @return zero on success
527 int avfilter_link(AVFilterContext *src, unsigned srcpad,
528 AVFilterContext *dst, unsigned dstpad);
531 * Negotiate the media format, dimensions, etc of all inputs to a filter.
533 * @param filter the filter to negotiate the properties for its inputs
534 * @return zero on successful negotiation
536 int avfilter_config_links(AVFilterContext *filter);
539 * Create a buffer reference wrapped around an already allocated image
542 * @param data pointers to the planes of the image to reference
543 * @param linesize linesizes for the planes of the image to reference
544 * @param perms the required access permissions
545 * @param w the width of the image specified by the data and linesize arrays
546 * @param h the height of the image specified by the data and linesize arrays
547 * @param format the pixel format of the image specified by the data and linesize arrays
550 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
551 int w, int h, enum AVPixelFormat format);
554 * Create an audio buffer reference wrapped around an already
555 * allocated samples buffer.
557 * @param data pointers to the samples plane buffers
558 * @param linesize linesize for the samples plane buffers
559 * @param perms the required access permissions
560 * @param nb_samples number of samples per channel
561 * @param sample_fmt the format of each sample in the buffer to allocate
562 * @param channel_layout the channel layout of the buffer
564 AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays(uint8_t **data,
568 enum AVSampleFormat sample_fmt,
569 uint64_t channel_layout);
571 /** Initialize the filter system. Register all builtin filters. */
572 void avfilter_register_all(void);
574 /** Uninitialize the filter system. Unregister all filters. */
575 void avfilter_uninit(void);
578 * Register a filter. This is only needed if you plan to use
579 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
580 * filter can still by instantiated with avfilter_open even if it is not
583 * @param filter the filter to register
584 * @return 0 if the registration was succesfull, a negative value
587 int avfilter_register(AVFilter *filter);
590 * Get a filter definition matching the given name.
592 * @param name the filter name to find
593 * @return the filter definition, if any matching one is registered.
594 * NULL if none found.
596 AVFilter *avfilter_get_by_name(const char *name);
599 * If filter is NULL, returns a pointer to the first registered filter pointer,
600 * if filter is non-NULL, returns the next pointer after filter.
601 * If the returned pointer points to NULL, the last registered filter
602 * was already reached.
604 AVFilter **av_filter_next(AVFilter **filter);
607 * Create a filter instance.
609 * @param filter_ctx put here a pointer to the created filter context
610 * on success, NULL on failure
611 * @param filter the filter to create an instance of
612 * @param inst_name Name to give to the new instance. Can be NULL for none.
613 * @return >= 0 in case of success, a negative error code otherwise
615 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
618 * Initialize a filter.
620 * @param filter the filter to initialize
621 * @param args A string of parameters to use when initializing the filter.
622 * The format and meaning of this string varies by filter.
623 * @param opaque Any extra non-string data needed by the filter. The meaning
624 * of this parameter varies by filter.
625 * @return zero on success
627 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
630 * Free a filter context.
632 * @param filter the filter to free
634 void avfilter_free(AVFilterContext *filter);
637 * Insert a filter in the middle of an existing link.
639 * @param link the link into which the filter should be inserted
640 * @param filt the filter to be inserted
641 * @param filt_srcpad_idx the input pad on the filter to connect
642 * @param filt_dstpad_idx the output pad on the filter to connect
643 * @return zero on success
645 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
646 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
649 * Copy the frame properties of src to dst, without copying the actual
652 * @return 0 on success, a negative number on error.
654 int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src);
657 * Copy the frame properties and data pointers of src to dst, without copying
660 * @return 0 on success, a negative number on error.
662 int avfilter_copy_buf_props(AVFrame *dst, const AVFilterBufferRef *src);
664 #endif /* AVFILTER_AVFILTER_H */