Create a set of null callback functions.
[libav.git] / libavfilter / avfilter.h
CommitLineData
a5cbb2f4 1/*
664f6595 2 * filter layer
a5cbb2f4
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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
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22#ifndef AVFILTER_AVFILTER_H
23#define AVFILTER_AVFILTER_H
a5cbb2f4 24
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25#include "libavutil/avutil.h"
26
0eb4ff9e 27#define LIBAVFILTER_VERSION_MAJOR 1
8955a324 28#define LIBAVFILTER_VERSION_MINOR 18
3fb8e77a 29#define LIBAVFILTER_VERSION_MICRO 0
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30
31#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
32 LIBAVFILTER_VERSION_MINOR, \
33 LIBAVFILTER_VERSION_MICRO)
34#define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
35 LIBAVFILTER_VERSION_MINOR, \
36 LIBAVFILTER_VERSION_MICRO)
37#define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
a7d46657 38
a9c81431 39#include <stddef.h>
245976da 40#include "libavcodec/avcodec.h"
a5cbb2f4 41
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42/**
43 * Returns the LIBAVFILTER_VERSION_INT constant.
44 */
45unsigned avfilter_version(void);
46
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47/**
48 * Returns the libavfilter build-time configuration.
49 */
41600690 50const char *avfilter_configuration(void);
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51
52/**
53 * Returns the libavfilter license.
54 */
41600690 55const char *avfilter_license(void);
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56
57
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58typedef struct AVFilterContext AVFilterContext;
59typedef struct AVFilterLink AVFilterLink;
60typedef struct AVFilterPad AVFilterPad;
61
62/* TODO: look for other flags which may be useful in this structure (interlace
63 * flags, etc)
64 */
65/**
38efe768 66 * A reference-counted picture data type used by the filter system. Filters
a5cbb2f4 67 * should not store pointers to this structure directly, but instead use the
664f6595 68 * AVFilterPicRef structure below.
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69 */
70typedef struct AVFilterPic
71{
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72 uint8_t *data[4]; ///< picture data for each plane
73 int linesize[4]; ///< number of bytes per line
74 enum PixelFormat format; ///< colorspace
a5cbb2f4 75
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76 unsigned refcount; ///< number of references to this image
77
78 /** private data to be used by a custom free function */
a5cbb2f4 79 void *priv;
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80 /**
81 * A pointer to the function to deallocate this image if the default
38efe768 82 * function is not sufficient. This could, for example, add the memory
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83 * back into a memory pool to be reused later without the overhead of
84 * reallocating it from scratch.
85 */
a5cbb2f4 86 void (*free)(struct AVFilterPic *pic);
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87
88 int w, h; ///< width and height of the allocated buffer
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89} AVFilterPic;
90
91/**
38efe768 92 * A reference to an AVFilterPic. Since filters can manipulate the origin of
a5cbb2f4 93 * a picture to, for example, crop image without any memcpy, the picture origin
38efe768 94 * and dimensions are per-reference properties. Linesize is also useful for
bbf42679 95 * image flipping, frame to field filters, etc, and so is also per-reference.
a5cbb2f4 96 *
1a18860a 97 * TODO: add anything necessary for frame reordering
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98 */
99typedef struct AVFilterPicRef
100{
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101 AVFilterPic *pic; ///< the picture that this is a reference to
102 uint8_t *data[4]; ///< picture data for each plane
103 int linesize[4]; ///< number of bytes per line
104 int w; ///< image width
105 int h; ///< image height
a5cbb2f4 106
056f0431 107 int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
5bb5c1dc 108 int64_t pos; ///< byte position in stream, -1 if unknown
1a18860a 109
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110 AVRational pixel_aspect; ///< pixel aspect ratio
111
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112 int perms; ///< permissions
113#define AV_PERM_READ 0x01 ///< can read from the buffer
114#define AV_PERM_WRITE 0x02 ///< can write to the buffer
115#define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
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116#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
117#define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
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118} AVFilterPicRef;
119
120/**
c5c6f626 121 * Adds a new reference to a picture.
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122 * @param ref an existing reference to the picture
123 * @param pmask a bitmask containing the allowable permissions in the new
13ff8fd0 124 * reference
664f6595 125 * @return a new reference to the picture with the same properties as the
13ff8fd0 126 * old, excluding any permissions denied by pmask
a5cbb2f4 127 */
16415eaf 128AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
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129
130/**
c5c6f626 131 * Removes a reference to a picture. If this is the last reference to the
a5cbb2f4 132 * picture, the picture itself is also automatically freed.
664f6595 133 * @param ref reference to the picture
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134 */
135void avfilter_unref_pic(AVFilterPicRef *ref);
136
13ff8fd0 137/**
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138 * A list of supported formats for one end of a filter link. This is used
139 * during the format negotiation process to try to pick the best format to
140 * use to minimize the number of necessary conversions. Each filter gives a
141 * list of the formats supported by each input and output pad. The list
142 * given for each pad need not be distinct - they may be references to the
143 * same list of formats, as is often the case when a filter supports multiple
42f72a3a 144 * formats, but will always output the same format as it is given in input.
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145 *
146 * In this way, a list of possible input formats and a list of possible
147 * output formats are associated with each link. When a set of formats is
148 * negotiated over a link, the input and output lists are merged to form a
149 * new list containing only the common elements of each list. In the case
150 * that there were no common elements, a format conversion is necessary.
151 * Otherwise, the lists are merged, and all other links which reference
152 * either of the format lists involved in the merge are also affected.
153 *
154 * For example, consider the filter chain:
155 * filter (a) --> (b) filter (b) --> (c) filter
156 *
157 * where the letters in parenthesis indicate a list of formats supported on
158 * the input or output of the link. Suppose the lists are as follows:
159 * (a) = {A, B}
160 * (b) = {A, B, C}
161 * (c) = {B, C}
162 *
163 * First, the first link's lists are merged, yielding:
164 * filter (a) --> (a) filter (a) --> (c) filter
165 *
166 * Notice that format list (b) now refers to the same list as filter list (a).
167 * Next, the lists for the second link are merged, yielding:
168 * filter (a) --> (a) filter (a) --> (a) filter
169 *
170 * where (a) = {B}.
171 *
172 * Unfortunately, when the format lists at the two ends of a link are merged,
173 * we must ensure that all links which reference either pre-merge format list
174 * get updated as well. Therefore, we have the format list structure store a
175 * pointer to each of the pointers to itself.
176 */
177typedef struct AVFilterFormats AVFilterFormats;
178struct AVFilterFormats
179{
180 unsigned format_count; ///< number of formats
930aa451 181 enum PixelFormat *formats; ///< list of pixel formats
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182
183 unsigned refcount; ///< number of references to this list
184 AVFilterFormats ***refs; ///< references to this list
185};
186
187/**
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188 * Creates a list of supported formats. This is intended for use in
189 * AVFilter->query_formats().
190 * @param pix_fmt list of pixel formats, terminated by PIX_FMT_NONE
191 * @return the format list, with no existing references
192 */
9abba21a 193AVFilterFormats *avfilter_make_format_list(const enum PixelFormat *pix_fmts);
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194
195/**
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196 * Adds pix_fmt to the list of pixel formats contained in *avff.
197 * If *avff is NULL the function allocates the filter formats struct
198 * and puts its pointer in *avff.
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199 *
200 * @return a non negative value in case of success, or a negative
201 * value corresponding to an AVERROR code in case of error
202 */
c1d662fd 203int avfilter_add_colorspace(AVFilterFormats **avff, enum PixelFormat pix_fmt);
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204
205/**
853961a9 206 * Returns a list of all colorspaces supported by FFmpeg.
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207 */
208AVFilterFormats *avfilter_all_colorspaces(void);
209
210/**
33a0facf 211 * Returns a format list which contains the intersection of the formats of
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212 * a and b. Also, all the references of a, all the references of b, and
213 * a and b themselves will be deallocated.
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214 *
215 * If a and b do not share any common formats, neither is modified, and NULL
216 * is returned.
217 */
218AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
219
09b63a42 220/**
a27c8d5f 221 * Adds *ref as a new reference to formats.
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222 * That is the pointers will point like in the ascii art below:
223 * ________
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224 * |formats |<--------.
225 * | ____ | ____|___________________
226 * | |refs| | | __|_
227 * | |* * | | | | | | AVFilterLink
09b63a42 228 * | |* *--------->|*ref|
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229 * | |____| | | |____|
230 * |________| |________________________
09b63a42 231 */
a27c8d5f 232void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
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233
234/**
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235 * If *ref is non-NULL, removes *ref as a reference to the format list
236 * it currently points to, deallocates that list if this was the last
237 * reference, and sets *ref to NULL.
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238 *
239 * Before After
240 * ________ ________ NULL
241 * |formats |<--------. |formats | ^
242 * | ____ | ____|________________ | ____ | ____|________________
243 * | |refs| | | __|_ | |refs| | | __|_
244 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
245 * | |* *--------->|*ref| | |* | | | |*ref|
246 * | |____| | | |____| | |____| | | |____|
247 * |________| |_____________________ |________| |_____________________
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248 */
249void avfilter_formats_unref(AVFilterFormats **ref);
250
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251/**
252 *
253 * Before After
254 * ________ ________
a27c8d5f 255 * |formats |<---------. |formats |<---------.
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256 * | ____ | ___|___ | ____ | ___|___
257 * | |refs| | | | | | |refs| | | | | NULL
258 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
259 * | |* * | | |_______| | |* * | | |_______| ___|___
260 * | |____| | | |____| | | | |
261 * |________| |________| |*oldref|
262 * |_______|
263 */
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264void avfilter_formats_changeref(AVFilterFormats **oldref,
265 AVFilterFormats **newref);
266
35f3fdf4 267/**
664f6595 268 * A filter pad used for either input or output.
13ff8fd0 269 */
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270struct AVFilterPad
271{
272 /**
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273 * Pad name. The name is unique among inputs and among outputs, but an
274 * input may have the same name as an output. This may be NULL if this
13ff8fd0 275 * pad has no need to ever be referenced by name.
a5cbb2f4 276 */
2844dd39 277 const char *name;
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278
279 /**
38efe768 280 * AVFilterPad type. Only video supported now, hopefully someone will
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281 * add audio in the future.
282 */
daafdb6e 283 enum CodecType type;
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284
285 /**
38efe768 286 * Minimum required permissions on incoming buffers. Any buffer with
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287 * insufficient permissions will be automatically copied by the filter
288 * system to a new buffer which provides the needed access permissions.
289 *
290 * Input pads only.
291 */
292 int min_perms;
293
294 /**
38efe768 295 * Permissions which are not accepted on incoming buffers. Any buffer
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296 * which has any of these permissions set will be automatically copied
297 * by the filter system to a new buffer which does not have those
38efe768 298 * permissions. This can be used to easily disallow buffers with
9ce95f27 299 * AV_PERM_REUSE.
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300 *
301 * Input pads only.
302 */
303 int rej_perms;
304
305 /**
38efe768 306 * Callback called before passing the first slice of a new frame. If
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307 * NULL, the filter layer will default to storing a reference to the
308 * picture inside the link structure.
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309 *
310 * Input video pads only.
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311 */
312 void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
313
314 /**
38efe768 315 * Callback function to get a buffer. If NULL, the filter system will
da23d424 316 * use avfilter_default_get_video_buffer().
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317 *
318 * Input video pads only.
a5cbb2f4 319 */
0eb4ff9e 320 AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
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321
322 /**
38efe768 323 * Callback called after the slices of a frame are completely sent. If
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324 * NULL, the filter layer will default to releasing the reference stored
325 * in the link structure during start_frame().
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326 *
327 * Input video pads only.
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328 */
329 void (*end_frame)(AVFilterLink *link);
330
331 /**
38efe768 332 * Slice drawing callback. This is where a filter receives video data
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333 * and should do its processing.
334 *
335 * Input video pads only.
a5cbb2f4 336 */
a13a5437 337 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
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338
339 /**
38efe768 340 * Frame poll callback. This returns the number of immediately available
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341 * frames. It should return a positive value if the next request_frame()
342 * is guaranteed to return one frame (with no delay).
343 *
344 * Defaults to just calling the source poll_frame() method.
345 *
346 * Output video pads only.
347 */
348 int (*poll_frame)(AVFilterLink *link);
349
350 /**
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351 * Frame request callback. A call to this should result in at least one
352 * frame being output over the given link. This should return zero on
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353 * success, and another value on error.
354 *
355 * Output video pads only.
a5cbb2f4 356 */
63f64e6f 357 int (*request_frame)(AVFilterLink *link);
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358
359 /**
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360 * Link configuration callback.
361 *
362 * For output pads, this should set the link properties such as
38efe768 363 * width/height. This should NOT set the format property - that is
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364 * negotiated between filters by the filter system using the
365 * query_formats() callback before this function is called.
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366 *
367 * For input pads, this should check the properties of the link, and update
368 * the filter's internal state as necessary.
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369 *
370 * For both input and output filters, this should return zero on success,
371 * and another value on error.
a5cbb2f4 372 */
d3e57c15 373 int (*config_props)(AVFilterLink *link);
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374};
375
2b187df9 376/** default handler for start_frame() for video inputs */
a5cbb2f4 377void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
b9609848 378/** default handler for draw_slice() for video inputs */
a13a5437 379void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
2b187df9 380/** default handler for end_frame() for video inputs */
a5cbb2f4 381void avfilter_default_end_frame(AVFilterLink *link);
2b187df9 382/** default handler for config_props() for video outputs */
901e6b39 383int avfilter_default_config_output_link(AVFilterLink *link);
2b187df9 384/** default handler for config_props() for video inputs */
85322466 385int avfilter_default_config_input_link (AVFilterLink *link);
2b187df9 386/** default handler for get_video_buffer() for video inputs */
901e6b39 387AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
0eb4ff9e 388 int perms, int w, int h);
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389/**
390 * A helper for query_formats() which sets all links to the same list of
391 * formats. If there are no links hooked to this filter, the list of formats is
392 * freed.
393 */
394void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
395/** Default handler for query_formats() */
396int avfilter_default_query_formats(AVFilterContext *ctx);
a5cbb2f4 397
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398/** start_frame() handler for filters which simply pass video along */
399void avfilter_null_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
400
401/** draw_slice() handler for filters which simply pass video along */
402void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
403
404/** end_frame() handler for filters which simply pass video along */
405void avfilter_null_end_frame(AVFilterLink *link);
406
407/** get_video_buffer() handler for filters which simply pass video along */
408AVFilterPicRef *avfilter_null_get_video_buffer(AVFilterLink *link,
409 int perms, int w, int h);
410
13ff8fd0 411/**
38efe768 412 * Filter definition. This defines the pads a filter contains, and all the
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413 * callback functions used to interact with the filter.
414 */
243110f9 415typedef struct AVFilter
a5cbb2f4 416{
2844dd39 417 const char *name; ///< filter name
a5cbb2f4 418
13ff8fd0 419 int priv_size; ///< size of private data to allocate for the filter
a5cbb2f4 420
4d96a914 421 /**
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422 * Filter initialization function. Args contains the user-supplied
423 * parameters. FIXME: maybe an AVOption-based system would be better?
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424 * opaque is data provided by the code requesting creation of the filter,
425 * and is used to pass data to the filter.
4d96a914 426 */
95bcf498 427 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
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428
429 /**
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430 * Filter uninitialization function. Should deallocate any memory held
431 * by the filter, release any picture references, etc. This does not need
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432 * to deallocate the AVFilterContext->priv memory itself.
433 */
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434 void (*uninit)(AVFilterContext *ctx);
435
35f3fdf4 436 /**
c4d2e41c 437 * Queries formats supported by the filter and its pads, and sets the
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438 * in_formats for links connected to its output pads, and out_formats
439 * for links connected to its input pads.
440 *
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441 * @return zero on success, a negative value corresponding to an
442 * AVERROR code otherwise
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443 */
444 int (*query_formats)(AVFilterContext *);
445
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446 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
447 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
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448
449 /**
450 * A description for the filter. You should use the
451 * NULL_IF_CONFIG_SMALL() macro to define it.
452 */
453 const char *description;
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454} AVFilter;
455
13ff8fd0 456/** An instance of a filter */
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457struct AVFilterContext
458{
d42a814e 459 const AVClass *av_class; ///< needed for av_log()
a5cbb2f4 460
664f6595 461 AVFilter *filter; ///< the AVFilter of which this is an instance
a5cbb2f4 462
13ff8fd0 463 char *name; ///< name of this filter instance
dcea2482 464
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465 unsigned input_count; ///< number of input pads
466 AVFilterPad *input_pads; ///< array of input pads
467 AVFilterLink **inputs; ///< array of pointers to input links
25f8e601 468
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469 unsigned output_count; ///< number of output pads
470 AVFilterPad *output_pads; ///< array of output pads
471 AVFilterLink **outputs; ///< array of pointers to output links
a5cbb2f4 472
13ff8fd0 473 void *priv; ///< private data for use by the filter
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474};
475
13ff8fd0 476/**
38efe768 477 * A link between two filters. This contains pointers to the source and
f4433de9 478 * destination filters between which this link exists, and the indexes of
38efe768 479 * the pads involved. In addition, this link also contains the parameters
13ff8fd0 480 * which have been negotiated and agreed upon between the filter, such as
2b187df9 481 * image dimensions, format, etc.
13ff8fd0 482 */
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483struct AVFilterLink
484{
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485 AVFilterContext *src; ///< source filter
486 unsigned int srcpad; ///< index of the output pad on the source filter
a5cbb2f4 487
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488 AVFilterContext *dst; ///< dest filter
489 unsigned int dstpad; ///< index of the input pad on the dest filter
a5cbb2f4 490
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491 /** stage of the initialization of the link properties (dimensions, etc) */
492 enum {
493 AVLINK_UNINIT = 0, ///< not started
494 AVLINK_STARTINIT, ///< started, but incomplete
495 AVLINK_INIT ///< complete
496 } init_state;
497
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498 int w; ///< agreed upon image width
499 int h; ///< agreed upon image height
500 enum PixelFormat format; ///< agreed upon image colorspace
a5cbb2f4 501
60bf6ce3 502 /**
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503 * Lists of formats supported by the input and output filters respectively.
504 * These lists are used for negotiating the format to actually be used,
505 * which will be loaded into the format member, above, when chosen.
506 */
507 AVFilterFormats *in_formats;
508 AVFilterFormats *out_formats;
509
510 /**
60bf6ce3 511 * The picture reference currently being sent across the link by the source
38efe768 512 * filter. This is used internally by the filter system to allow
664f6595 513 * automatic copying of pictures which do not have sufficient permissions
38efe768 514 * for the destination. This should not be accessed directly by the
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515 * filters.
516 */
517 AVFilterPicRef *srcpic;
518
a5cbb2f4 519 AVFilterPicRef *cur_pic;
462f57db 520 AVFilterPicRef *outpic;
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521};
522
13ff8fd0 523/**
c5c6f626 524 * Links two filters together.
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525 * @param src the source filter
526 * @param srcpad index of the output pad on the source filter
527 * @param dst the destination filter
528 * @param dstpad index of the input pad on the destination filter
529 * @return zero on success
13ff8fd0 530 */
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531int avfilter_link(AVFilterContext *src, unsigned srcpad,
532 AVFilterContext *dst, unsigned dstpad);
533
13ff8fd0 534/**
c5c6f626 535 * Negotiates the colorspace, dimensions, etc of all inputs to a filter.
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536 * @param filter the filter to negotiate the properties for its inputs
537 * @return zero on successful negotiation
13ff8fd0 538 */
24c4eff6 539int avfilter_config_links(AVFilterContext *filter);
85322466 540
13ff8fd0 541/**
c5c6f626 542 * Requests a picture buffer with a specific set of permissions.
664f6595 543 * @param link the output link to the filter from which the picture will
13ff8fd0 544 * be requested
664f6595 545 * @param perms the required access permissions
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546 * @param w the minimum width of the buffer to allocate
547 * @param h the minimum height of the buffer to allocate
38efe768 548 * @return A reference to the picture. This must be unreferenced with
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549 * avfilter_unref_pic when you are finished with it.
550 */
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551AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
552 int w, int h);
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553
554/**
c5c6f626 555 * Requests an input frame from the filter at the other end of the link.
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556 * @param link the input link
557 * @return zero on success
13ff8fd0 558 */
0155b1a1 559int avfilter_request_frame(AVFilterLink *link);
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560
561/**
c5c6f626 562 * Polls a frame from the filter chain.
b04c740a 563 * @param link the input link
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564 * @return the number of immediately available frames, a negative
565 * number in case of error
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566 */
567int avfilter_poll_frame(AVFilterLink *link);
568
569/**
c5c6f626 570 * Notifies the next filter of the start of a frame.
664f6595 571 * @param link the output link the frame will be sent over
38efe768 572 * @param picref A reference to the frame about to be sent. The data for this
13ff8fd0 573 * frame need only be valid once draw_slice() is called for that
38efe768 574 * portion. The receiving filter will free this reference when
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575 * it no longer needs it.
576 */
a5cbb2f4 577void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
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578
579/**
c5c6f626 580 * Notifies the next filter that the current frame has finished.
664f6595 581 * @param link the output link the frame was sent over
13ff8fd0 582 */
a5cbb2f4 583void avfilter_end_frame(AVFilterLink *link);
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584
585/**
c5c6f626 586 * Sends a slice to the next filter.
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587 *
588 * Slices have to be provided in sequential order, either in
589 * top-bottom or bottom-top order. If slices are provided in
590 * non-sequential order the behavior of the function is undefined.
591 *
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592 * @param link the output link over which the frame is being sent
593 * @param y offset in pixels from the top of the image for this slice
594 * @param h height of this slice in pixels
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595 * @param slice_dir the assumed direction for sending slices,
596 * from the top slice to the bottom slice if the value is 1,
597 * from the bottom slice to the top slice if the value is -1,
598 * for other values the behavior of the function is undefined.
13ff8fd0 599 */
a13a5437 600void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
a5cbb2f4 601
2be414c8 602/** Initializes the filter system. Registers all builtin filters. */
11de6cac 603void avfilter_register_all(void);
e4152452 604
2be414c8 605/** Uninitializes the filter system. Unregisters all filters. */
a5cbb2f4 606void avfilter_uninit(void);
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607
608/**
c5c6f626 609 * Registers a filter. This is only needed if you plan to use
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610 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
611 * filter can still by instantiated with avfilter_open even if it is not
612 * registered.
664f6595 613 * @param filter the filter to register
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614 * @return 0 if the registration was succesfull, a negative value
615 * otherwise
13ff8fd0 616 */
86a60fa1 617int avfilter_register(AVFilter *filter);
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618
619/**
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620 * Gets a filter definition matching the given name.
621 * @param name the filter name to find
622 * @return the filter definition, if any matching one is registered.
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623 * NULL if none found.
624 */
2844dd39 625AVFilter *avfilter_get_by_name(const char *name);
a5cbb2f4 626
13ff8fd0 627/**
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628 * If filter is NULL, returns a pointer to the first registered filter pointer,
629 * if filter is non-NULL, returns the next pointer after filter.
630 * If the returned pointer points to NULL, the last registered filter
631 * was already reached.
632 */
633AVFilter **av_filter_next(AVFilter **filter);
634
635/**
c5c6f626 636 * Creates a filter instance.
664f6595 637 * @param filter the filter to create an instance of
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638 * @param inst_name Name to give to the new instance. Can be NULL for none.
639 * @return Pointer to the new instance on success. NULL on failure.
13ff8fd0 640 */
2844dd39 641AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
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642
643/**
c5c6f626 644 * Initializes a filter.
664f6595 645 * @param filter the filter to initialize
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646 * @param args A string of parameters to use when initializing the filter.
647 * The format and meaning of this string varies by filter.
38efe768 648 * @param opaque Any extra non-string data needed by the filter. The meaning
13ff8fd0 649 * of this parameter varies by filter.
664f6595 650 * @return zero on success
13ff8fd0 651 */
6e365c57 652int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
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653
654/**
c5c6f626 655 * Destroys a filter.
664f6595 656 * @param filter the filter to destroy
13ff8fd0 657 */
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658void avfilter_destroy(AVFilterContext *filter);
659
13ff8fd0 660/**
c5c6f626 661 * Inserts a filter in the middle of an existing link.
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662 * @param link the link into which the filter should be inserted
663 * @param filt the filter to be inserted
664 * @param in the input pad on the filter to connect
665 * @param out the output pad on the filter to connect
666 * @return zero on success
13ff8fd0 667 */
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668int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
669 unsigned in, unsigned out);
d3e57c15 670
a9c81431 671/**
c5c6f626 672 * Inserts a new pad.
38efe768 673 * @param idx Insertion point. Pad is inserted at the end if this point
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674 * is beyond the end of the list of pads.
675 * @param count Pointer to the number of pads in the list
676 * @param padidx_off Offset within an AVFilterLink structure to the element
677 * to increment when inserting a new pad causes link
678 * numbering to change
679 * @param pads Pointer to the pointer to the beginning of the list of pads
680 * @param links Pointer to the pointer to the beginning of the list of links
681 * @param newpad The new pad to add. A copy is made when adding.
682 */
683void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
684 AVFilterPad **pads, AVFilterLink ***links,
685 AVFilterPad *newpad);
686
c5c6f626 687/** Inserts a new input pad for the filter. */
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688static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
689 AVFilterPad *p)
690{
691 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
692 &f->input_pads, &f->inputs, p);
693}
694
c5c6f626 695/** Inserts a new output pad for the filter. */
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696static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
697 AVFilterPad *p)
698{
699 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
700 &f->output_pads, &f->outputs, p);
701}
702
98790382 703#endif /* AVFILTER_AVFILTER_H */