Add pixel aspect ratio to AVFilterPicRef structure
[libav.git] / libavfilter / avfilter.h
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1/*
2 * Filter layer
3 * copyright (c) 2007 Bobby Bingham
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22#ifndef FFMPEG_AVFILTER_H
23#define FFMPEG_AVFILTER_H
24
a9c81431 25#include <stddef.h>
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26#include "avcodec.h"
27
28typedef struct AVFilterContext AVFilterContext;
29typedef struct AVFilterLink AVFilterLink;
30typedef struct AVFilterPad AVFilterPad;
31
32/* TODO: look for other flags which may be useful in this structure (interlace
33 * flags, etc)
34 */
35/**
36 * A reference-counted picture data type used by the filter system. Filters
37 * should not store pointers to this structure directly, but instead use the
38 * AVFilterPicRef structure below
39 */
40typedef struct AVFilterPic
41{
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42 uint8_t *data[4]; ///< picture data for each plane
43 int linesize[4]; ///< number of bytes per line
44 enum PixelFormat format; ///< colorspace
a5cbb2f4 45
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46 unsigned refcount; ///< number of references to this image
47
48 /** private data to be used by a custom free function */
a5cbb2f4 49 void *priv;
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50 /**
51 * A pointer to the function to deallocate this image if the default
52 * function is not sufficient. This could, for example, add the memory
53 * back into a memory pool to be reused later without the overhead of
54 * reallocating it from scratch.
55 */
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56 void (*free)(struct AVFilterPic *pic);
57} AVFilterPic;
58
59/**
60 * A reference to an AVFilterPic. Since filters can manipulate the origin of
61 * a picture to, for example, crop image without any memcpy, the picture origin
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62 * and dimensions are per-reference properties. Linesize is also useful for
63 * image flipping, frame to field filters, etc, and so is also per-reference.
a5cbb2f4 64 *
1a18860a 65 * TODO: add anything necessary for frame reordering
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66 */
67typedef struct AVFilterPicRef
68{
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69 AVFilterPic *pic; ///< the picture that this is a reference to
70 uint8_t *data[4]; ///< picture data for each plane
71 int linesize[4]; ///< number of bytes per line
72 int w; ///< image width
73 int h; ///< image height
a5cbb2f4 74
056f0431 75 int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
1a18860a 76
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77 AVRational pixel_aspect; ///< pixel aspect ratio
78
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79 int perms; ///< permissions
80#define AV_PERM_READ 0x01 ///< can read from the buffer
81#define AV_PERM_WRITE 0x02 ///< can write to the buffer
82#define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
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83#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
84#define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
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85} AVFilterPicRef;
86
87/**
88 * Add a new reference to a picture.
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89 * @param ref An existing reference to the picture
90 * @param pmask A bitmask containing the allowable permissions in the new
91 * reference
92 * @return A new reference to the picture with the same properties as the
93 * old, excluding any permissions denied by pmask
a5cbb2f4 94 */
16415eaf 95AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
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96
97/**
98 * Remove a reference to a picture. If this is the last reference to the
99 * picture, the picture itself is also automatically freed.
100 * @param ref Reference to the picture.
101 */
102void avfilter_unref_pic(AVFilterPicRef *ref);
103
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104/**
105 * A filter pad used for either input or output
106 */
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107struct AVFilterPad
108{
109 /**
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110 * Pad name. The name is unique among inputs and among outputs, but an
111 * input may have the same name as an output. This may be NULL if this
112 * pad has no need to ever be referenced by name.
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113 */
114 char *name;
115
116 /**
117 * AVFilterPad type. Only video supported now, hopefully someone will
118 * add audio in the future.
119 */
120 int type;
13ff8fd0 121#define AV_PAD_VIDEO 0 ///< video pad
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122
123 /**
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124 * Minimum required permissions on incoming buffers. Any buffers with
125 * insufficient permissions will be automatically copied by the filter
126 * system to a new buffer which provides the needed access permissions.
127 *
128 * Input pads only.
129 */
130 int min_perms;
131
132 /**
133 * Permissions which are not accepted on incoming buffers. Any buffer
134 * which has any of these permissions set be automatically copied by the
135 * filter system to a new buffer which does not have those permissions.
136 * This can be used to easily disallow buffers with AV_PERM_REUSE.
137 *
138 * Input pads only.
139 */
140 int rej_perms;
141
142 /**
d3e57c15 143 * Callback to get a list of supported formats. The returned list should
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144 * be terminated by -1 (see avfilter_make_format_list for an easy way to
145 * create such a list).
146 *
147 * This is used for both input and output pads. If ommitted from an output
148 * pad, it is assumed that the only format supported is the same format
149 * that is being used for the filter's first input. If the filter has no
150 * inputs, then this may not be ommitted for its output pads.
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151 */
152 int *(*query_formats)(AVFilterLink *link);
153
154 /**
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155 * Callback called before passing the first slice of a new frame. If
156 * NULL, the filter layer will default to storing a reference to the
157 * picture inside the link structure.
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158 *
159 * Input video pads only.
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160 */
161 void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
162
163 /**
164 * Callback function to get a buffer. If NULL, the filter system will
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165 * handle buffer requests.
166 *
167 * Input video pads only.
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168 */
169 AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms);
170
171 /**
172 * Callback called after the slices of a frame are completely sent. If
173 * NULL, the filter layer will default to releasing the reference stored
174 * in the link structure during start_frame().
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175 *
176 * Input video pads only.
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177 */
178 void (*end_frame)(AVFilterLink *link);
179
180 /**
181 * Slice drawing callback. This is where a filter receives video data
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182 * and should do its processing.
183 *
184 * Input video pads only.
a5cbb2f4 185 */
72f6d631 186 void (*draw_slice)(AVFilterLink *link, int y, int height);
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187
188 /**
189 * Frame request callback. A call to this should result in at least one
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190 * frame being output over the given link. This should return zero on
191 * success, and another value on error.
192 *
193 * Output video pads only.
a5cbb2f4 194 */
63f64e6f 195 int (*request_frame)(AVFilterLink *link);
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196
197 /**
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198 * Link configuration callback.
199 *
200 * For output pads, this should set the link properties such as
201 * width/height. This should NOT set the format property - that is
202 * negotiated between filters by the filter system using the
203 * query_formats() callback before this function is called.
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204 *
205 * For input pads, this should check the properties of the link, and update
206 * the filter's internal state as necessary.
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207 *
208 * For both input and output filters, this should return zero on success,
209 * and another value on error.
a5cbb2f4 210 */
d3e57c15 211 int (*config_props)(AVFilterLink *link);
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212};
213
13ff8fd0 214/** Default handler for start_frame() for video inputs */
a5cbb2f4 215void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
13ff8fd0 216/** Default handler for end_frame() for video inputs */
a5cbb2f4 217void avfilter_default_end_frame(AVFilterLink *link);
13ff8fd0 218/** Default handler for config_props() for video outputs */
901e6b39 219int avfilter_default_config_output_link(AVFilterLink *link);
13ff8fd0 220/** Default handler for config_props() for video inputs */
85322466 221int avfilter_default_config_input_link (AVFilterLink *link);
13ff8fd0 222/** Default handler for query_formats() for video outputs */
901e6b39 223int *avfilter_default_query_output_formats(AVFilterLink *link);
13ff8fd0 224/** Default handler for get_video_buffer() for video inputs */
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225AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
226 int perms);
a5cbb2f4 227
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228/**
229 * Filter definition. This defines the pads a filter contains, and all the
230 * callback functions used to interact with the filter.
231 */
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232typedef struct
233{
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234 char *name; ///< filter name
235 char *author; ///< filter author
a5cbb2f4 236
13ff8fd0 237 int priv_size; ///< size of private data to allocate for the filter
a5cbb2f4 238
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239 /**
240 * Filter initialization function. Args contains the user-supplied
241 * parameters. FIXME: maybe an AVOption-based system would be better?
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242 * opaque is data provided by the code requesting creation of the filter,
243 * and is used to pass data to the filter.
4d96a914 244 */
95bcf498 245 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
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246
247 /**
248 * Filter uninitialization function. Should deallocate any memory held
249 * by the filter, release any picture references, etc. This does not need
250 * to deallocate the AVFilterContext->priv memory itself.
251 */
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252 void (*uninit)(AVFilterContext *ctx);
253
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254 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
255 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
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256} AVFilter;
257
13ff8fd0 258/** An instance of a filter */
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259struct AVFilterContext
260{
13ff8fd0 261 AVClass *av_class; ///< Needed for av_log()
a5cbb2f4 262
13ff8fd0 263 AVFilter *filter; ///< The AVFilter of which this is an instance
a5cbb2f4 264
13ff8fd0 265 char *name; ///< name of this filter instance
dcea2482 266
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267 unsigned input_count; ///< number of input pads
268 AVFilterPad *input_pads; ///< array of input pads
269 AVFilterLink **inputs; ///< array of pointers to input links
25f8e601 270
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271 unsigned output_count; ///< number of output pads
272 AVFilterPad *output_pads; ///< array of output pads
273 AVFilterLink **outputs; ///< array of pointers to output links
a5cbb2f4 274
13ff8fd0 275 void *priv; ///< private data for use by the filter
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276};
277
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278/**
279 * A links between two filters. This contains pointers to the source and
280 * destination filters between which this link exists, and the indices of
281 * the pads involved. In addition, this link also contains the parameters
282 * which have been negotiated and agreed upon between the filter, such as
283 * image dimensions, format, etc
284 */
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285struct AVFilterLink
286{
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287 AVFilterContext *src; ///< source filter
288 unsigned int srcpad; ///< index of the output pad on the source filter
a5cbb2f4 289
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290 AVFilterContext *dst; ///< dest filter
291 unsigned int dstpad; ///< index of the input pad on the dest filter
a5cbb2f4 292
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293 int w; ///< agreed upon image width
294 int h; ///< agreed upon image height
295 enum PixelFormat format; ///< agreed upon image colorspace
a5cbb2f4 296
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297 /**
298 * The picture reference currently being sent across the link by the source
299 * filter. This is used internally by the filter system to allow
300 * automatic copying of pictures which d not have sufficient permissions
301 * for the destination. This should not be accessed directly by the
302 * filters.
303 */
304 AVFilterPicRef *srcpic;
305
a5cbb2f4 306 AVFilterPicRef *cur_pic;
462f57db 307 AVFilterPicRef *outpic;
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308};
309
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310/**
311 * Link two filters together
312 * @param src The source filter
313 * @param srcpad Index of the output pad on the source filter
314 * @param dst The destination filter
315 * @param dstpad Index of the input pad on the destination filter
316 * @return Zero on success
317 */
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318int avfilter_link(AVFilterContext *src, unsigned srcpad,
319 AVFilterContext *dst, unsigned dstpad);
320
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321/**
322 * Negotiate the colorspace, dimensions, etc of a link
323 * @param link The link to negotiate the properties of
324 * @return Zero on successful negotiation
325 */
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326int avfilter_config_link(AVFilterLink *link);
327
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328/**
329 * Request a picture buffer with a specific set of permissions
330 * @param link The output link to the filter from which the picture will
331 * be requested
332 * @param perms The required access permissions
333 * @return A reference to the picture. This must be unreferenced with
334 * avfilter_unref_pic when you are finished with it.
335 */
a5cbb2f4 336AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);
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337
338/**
339 * Request an input frame from the filter at the other end of the link.
340 * @param link The input link
341 * @return Zero on success
342 */
63f64e6f 343int avfilter_request_frame(AVFilterLink *link);
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344
345/**
b42a6a92 346 * Notify the next filter of the start of a frame.
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347 * @param link The output link the frame will be sent over
348 * @param picref A reference to the frame about to be sent. The data for this
349 * frame need only be valid once draw_slice() is called for that
350 * portion. The receiving filter will free this reference when
351 * it no longer needs it.
352 */
a5cbb2f4 353void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
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354
355/**
356 * Notify the next filter that the current frame has finished
357 * @param link The output link the frame was sent over
358 */
a5cbb2f4 359void avfilter_end_frame(AVFilterLink *link);
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360
361/**
362 * Send a slice to the next filter
363 * @param link The output link over which the frame is being sent
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364 * @param y Offset in pixels from the top of the image for this slice
365 * @param h Height of this slice in pixels
366 */
72f6d631 367void avfilter_draw_slice(AVFilterLink *link, int y, int h);
a5cbb2f4 368
13ff8fd0 369/** Initialize the filter system. Registers all builtin filters */
a5cbb2f4 370void avfilter_init(void);
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371
372/** Uninitialize the filter system. Unregisters all filters */
a5cbb2f4 373void avfilter_uninit(void);
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374
375/**
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376 * Register a filter. This is only needed if you plan to use
377 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
378 * filter can still by instantiated with avfilter_open even if it is not
379 * registered.
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380 * @param filter The filter to register
381 */
a5cbb2f4 382void avfilter_register(AVFilter *filter);
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383
384/**
385 * Gets a filter definition matching the given name
386 * @param name The filter name to find
387 * @return The filter definition, if any matching one is registered.
388 * NULL if none found.
389 */
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390AVFilter *avfilter_get_by_name(char *name);
391
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392/**
393 * Create a filter instance
394 * @param filter The filter to create an instance of
395 * @param inst_name Name to give to the new instance. Can be NULL for none.
396 * @return Pointer to the new instance on success. NULL on failure.
397 */
fc815c56 398AVFilterContext *avfilter_open(AVFilter *filter, char *inst_name);
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399
400/**
401 * Initialize a filter
402 * @param filter The filter to initialize
403 * @param args A string of parameters to use when initializing the filter.
404 * The format and meaning of this string varies by filter.
405 * @param opaque Any extra non-string data needed by the filter. The meaning
406 * of this parameter varies by filter.
407 * @return Zero on success
408 */
6e365c57 409int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
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410
411/**
412 * Destroy a filter
413 * @param filter The filter to destroy
414 */
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415void avfilter_destroy(AVFilterContext *filter);
416
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417/**
418 * Helper function to create a list of supported formats. This is intended
419 * for use in AVFilterPad->query_formats().
420 * @param len The number of formats supported
421 * @param ... A list of the supported formats
422 * @return The format list in a form suitable for returning from
423 * AVFilterPad->query_formats()
424 */
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425int *avfilter_make_format_list(int len, ...);
426
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427/**
428 * Insert a new pad
429 * @param idx Insertion point. Pad is inserted at the end if this point
430 * is beyond the end of the list of pads.
431 * @param count Pointer to the number of pads in the list
432 * @param padidx_off Offset within an AVFilterLink structure to the element
433 * to increment when inserting a new pad causes link
434 * numbering to change
435 * @param pads Pointer to the pointer to the beginning of the list of pads
436 * @param links Pointer to the pointer to the beginning of the list of links
437 * @param newpad The new pad to add. A copy is made when adding.
438 */
439void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
440 AVFilterPad **pads, AVFilterLink ***links,
441 AVFilterPad *newpad);
442
443/** insert a new input pad for the filter */
444static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
445 AVFilterPad *p)
446{
447 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
448 &f->input_pads, &f->inputs, p);
449}
450
451/** insert a new output pad for the filter */
452static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
453 AVFilterPad *p)
454{
455 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
456 &f->output_pads, &f->outputs, p);
457}
458
a5cbb2f4 459#endif /* FFMPEG_AVFILTER_H */