Document create_filter().
[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
b5c582fa 28#define LIBAVFILTER_VERSION_MINOR 25
9f0e31d2 29#define LIBAVFILTER_VERSION_MICRO 1
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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
540f1c7b 42/**
49bd8e4b 43 * Return the LIBAVFILTER_VERSION_INT constant.
540f1c7b
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44 */
45unsigned avfilter_version(void);
46
c1736936 47/**
49bd8e4b 48 * Return the libavfilter build-time configuration.
c1736936 49 */
41600690 50const char *avfilter_configuration(void);
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51
52/**
49bd8e4b 53 * Return the libavfilter license.
c1736936 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
a5cbb2f4 62/**
32d7bcd4 63 * A reference-counted buffer data type used by the filter system. Filters
a5cbb2f4 64 * should not store pointers to this structure directly, but instead use the
664f6595 65 * AVFilterPicRef structure below.
a5cbb2f4 66 */
f0d77b20 67typedef struct AVFilterBuffer
a5cbb2f4 68{
32d7bcd4 69 uint8_t *data[4]; ///< buffer data for each plane
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70 int linesize[4]; ///< number of bytes per line
71 enum PixelFormat format; ///< colorspace
a5cbb2f4 72
32d7bcd4 73 unsigned refcount; ///< number of references to this buffer
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74
75 /** private data to be used by a custom free function */
a5cbb2f4 76 void *priv;
13ff8fd0 77 /**
32d7bcd4 78 * A pointer to the function to deallocate this buffer if the default
38efe768 79 * function is not sufficient. This could, for example, add the memory
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80 * back into a memory pool to be reused later without the overhead of
81 * reallocating it from scratch.
82 */
32d7bcd4 83 void (*free)(struct AVFilterBuffer *buf);
f0d77b20 84} AVFilterBuffer;
a5cbb2f4 85
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86#define AV_PERM_READ 0x01 ///< can read from the buffer
87#define AV_PERM_WRITE 0x02 ///< can write to the buffer
88#define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
89#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
90#define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
91
a5cbb2f4 92/**
f0d77b20 93 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
a5cbb2f4 94 * a picture to, for example, crop image without any memcpy, the picture origin
38efe768 95 * and dimensions are per-reference properties. Linesize is also useful for
bbf42679 96 * image flipping, frame to field filters, etc, and so is also per-reference.
a5cbb2f4 97 *
1a18860a 98 * TODO: add anything necessary for frame reordering
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99 */
100typedef struct AVFilterPicRef
101{
f0d77b20 102 AVFilterBuffer *pic; ///< the picture that this is a reference to
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103 uint8_t *data[4]; ///< picture data for each plane
104 int linesize[4]; ///< number of bytes per line
105 int w; ///< image width
106 int h; ///< image height
a5cbb2f4 107
056f0431 108 int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
5bb5c1dc 109 int64_t pos; ///< byte position in stream, -1 if unknown
1a18860a 110
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111 AVRational pixel_aspect; ///< pixel aspect ratio
112
ff5f1be0 113 int perms; ///< permissions, see the AV_PERM_* flags
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114
115 int interlaced; ///< is frame interlaced
116 int top_field_first;
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117} AVFilterPicRef;
118
119/**
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120 * Copy properties of src to dst, without copying the actual video
121 * data.
122 */
123static inline void avfilter_copy_picref_props(AVFilterPicRef *dst, AVFilterPicRef *src)
124{
125 dst->pts = src->pts;
126 dst->pos = src->pos;
127 dst->pixel_aspect = src->pixel_aspect;
128 dst->interlaced = src->interlaced;
129 dst->top_field_first = src->top_field_first;
130}
131
132/**
49bd8e4b 133 * Add a new reference to a picture.
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134 * @param ref an existing reference to the picture
135 * @param pmask a bitmask containing the allowable permissions in the new
13ff8fd0 136 * reference
664f6595 137 * @return a new reference to the picture with the same properties as the
13ff8fd0 138 * old, excluding any permissions denied by pmask
a5cbb2f4 139 */
16415eaf 140AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
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141
142/**
49bd8e4b 143 * Remove a reference to a picture. If this is the last reference to the
a5cbb2f4 144 * picture, the picture itself is also automatically freed.
664f6595 145 * @param ref reference to the picture
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146 */
147void avfilter_unref_pic(AVFilterPicRef *ref);
148
13ff8fd0 149/**
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150 * A list of supported formats for one end of a filter link. This is used
151 * during the format negotiation process to try to pick the best format to
152 * use to minimize the number of necessary conversions. Each filter gives a
153 * list of the formats supported by each input and output pad. The list
154 * given for each pad need not be distinct - they may be references to the
155 * same list of formats, as is often the case when a filter supports multiple
42f72a3a 156 * formats, but will always output the same format as it is given in input.
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157 *
158 * In this way, a list of possible input formats and a list of possible
159 * output formats are associated with each link. When a set of formats is
160 * negotiated over a link, the input and output lists are merged to form a
161 * new list containing only the common elements of each list. In the case
162 * that there were no common elements, a format conversion is necessary.
163 * Otherwise, the lists are merged, and all other links which reference
164 * either of the format lists involved in the merge are also affected.
165 *
166 * For example, consider the filter chain:
167 * filter (a) --> (b) filter (b) --> (c) filter
168 *
169 * where the letters in parenthesis indicate a list of formats supported on
170 * the input or output of the link. Suppose the lists are as follows:
171 * (a) = {A, B}
172 * (b) = {A, B, C}
173 * (c) = {B, C}
174 *
175 * First, the first link's lists are merged, yielding:
176 * filter (a) --> (a) filter (a) --> (c) filter
177 *
178 * Notice that format list (b) now refers to the same list as filter list (a).
179 * Next, the lists for the second link are merged, yielding:
180 * filter (a) --> (a) filter (a) --> (a) filter
181 *
182 * where (a) = {B}.
183 *
184 * Unfortunately, when the format lists at the two ends of a link are merged,
185 * we must ensure that all links which reference either pre-merge format list
186 * get updated as well. Therefore, we have the format list structure store a
187 * pointer to each of the pointers to itself.
188 */
189typedef struct AVFilterFormats AVFilterFormats;
190struct AVFilterFormats
191{
192 unsigned format_count; ///< number of formats
930aa451 193 enum PixelFormat *formats; ///< list of pixel formats
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194
195 unsigned refcount; ///< number of references to this list
196 AVFilterFormats ***refs; ///< references to this list
197};
198
199/**
49bd8e4b 200 * Create a list of supported formats. This is intended for use in
f6a1fa85 201 * AVFilter->query_formats().
9a58234f 202 * @param pix_fmts list of pixel formats, terminated by PIX_FMT_NONE
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203 * @return the format list, with no existing references
204 */
9abba21a 205AVFilterFormats *avfilter_make_format_list(const enum PixelFormat *pix_fmts);
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206
207/**
49bd8e4b 208 * Add pix_fmt to the list of pixel formats contained in *avff.
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209 * If *avff is NULL the function allocates the filter formats struct
210 * and puts its pointer in *avff.
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211 *
212 * @return a non negative value in case of success, or a negative
213 * value corresponding to an AVERROR code in case of error
214 */
c1d662fd 215int avfilter_add_colorspace(AVFilterFormats **avff, enum PixelFormat pix_fmt);
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216
217/**
49bd8e4b 218 * Return a list of all colorspaces supported by FFmpeg.
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219 */
220AVFilterFormats *avfilter_all_colorspaces(void);
221
222/**
49bd8e4b 223 * Return a format list which contains the intersection of the formats of
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224 * a and b. Also, all the references of a, all the references of b, and
225 * a and b themselves will be deallocated.
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226 *
227 * If a and b do not share any common formats, neither is modified, and NULL
228 * is returned.
229 */
230AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
231
09b63a42 232/**
49bd8e4b 233 * Add *ref as a new reference to formats.
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234 * That is the pointers will point like in the ascii art below:
235 * ________
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236 * |formats |<--------.
237 * | ____ | ____|___________________
238 * | |refs| | | __|_
239 * | |* * | | | | | | AVFilterLink
09b63a42 240 * | |* *--------->|*ref|
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241 * | |____| | | |____|
242 * |________| |________________________
09b63a42 243 */
a27c8d5f 244void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
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245
246/**
49bd8e4b 247 * If *ref is non-NULL, remove *ref as a reference to the format list
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248 * it currently points to, deallocates that list if this was the last
249 * reference, and sets *ref to NULL.
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250 *
251 * Before After
252 * ________ ________ NULL
253 * |formats |<--------. |formats | ^
254 * | ____ | ____|________________ | ____ | ____|________________
255 * | |refs| | | __|_ | |refs| | | __|_
256 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
257 * | |* *--------->|*ref| | |* | | | |*ref|
258 * | |____| | | |____| | |____| | | |____|
259 * |________| |_____________________ |________| |_____________________
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260 */
261void avfilter_formats_unref(AVFilterFormats **ref);
262
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263/**
264 *
265 * Before After
266 * ________ ________
a27c8d5f 267 * |formats |<---------. |formats |<---------.
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268 * | ____ | ___|___ | ____ | ___|___
269 * | |refs| | | | | | |refs| | | | | NULL
270 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
271 * | |* * | | |_______| | |* * | | |_______| ___|___
272 * | |____| | | |____| | | | |
273 * |________| |________| |*oldref|
274 * |_______|
275 */
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276void avfilter_formats_changeref(AVFilterFormats **oldref,
277 AVFilterFormats **newref);
278
35f3fdf4 279/**
664f6595 280 * A filter pad used for either input or output.
13ff8fd0 281 */
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282struct AVFilterPad
283{
284 /**
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285 * Pad name. The name is unique among inputs and among outputs, but an
286 * input may have the same name as an output. This may be NULL if this
13ff8fd0 287 * pad has no need to ever be referenced by name.
a5cbb2f4 288 */
2844dd39 289 const char *name;
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290
291 /**
38efe768 292 * AVFilterPad type. Only video supported now, hopefully someone will
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293 * add audio in the future.
294 */
72415b2a 295 enum AVMediaType type;
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296
297 /**
38efe768 298 * Minimum required permissions on incoming buffers. Any buffer with
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299 * insufficient permissions will be automatically copied by the filter
300 * system to a new buffer which provides the needed access permissions.
301 *
302 * Input pads only.
303 */
304 int min_perms;
305
306 /**
38efe768 307 * Permissions which are not accepted on incoming buffers. Any buffer
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308 * which has any of these permissions set will be automatically copied
309 * by the filter system to a new buffer which does not have those
38efe768 310 * permissions. This can be used to easily disallow buffers with
9ce95f27 311 * AV_PERM_REUSE.
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312 *
313 * Input pads only.
314 */
315 int rej_perms;
316
317 /**
38efe768 318 * Callback called before passing the first slice of a new frame. If
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319 * NULL, the filter layer will default to storing a reference to the
320 * picture inside the link structure.
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321 *
322 * Input video pads only.
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323 */
324 void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
325
326 /**
38efe768 327 * Callback function to get a buffer. If NULL, the filter system will
da23d424 328 * use avfilter_default_get_video_buffer().
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329 *
330 * Input video pads only.
a5cbb2f4 331 */
0eb4ff9e 332 AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
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333
334 /**
38efe768 335 * Callback called after the slices of a frame are completely sent. If
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336 * NULL, the filter layer will default to releasing the reference stored
337 * in the link structure during start_frame().
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338 *
339 * Input video pads only.
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340 */
341 void (*end_frame)(AVFilterLink *link);
342
343 /**
38efe768 344 * Slice drawing callback. This is where a filter receives video data
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345 * and should do its processing.
346 *
347 * Input video pads only.
a5cbb2f4 348 */
a13a5437 349 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
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350
351 /**
38efe768 352 * Frame poll callback. This returns the number of immediately available
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353 * frames. It should return a positive value if the next request_frame()
354 * is guaranteed to return one frame (with no delay).
355 *
356 * Defaults to just calling the source poll_frame() method.
357 *
358 * Output video pads only.
359 */
360 int (*poll_frame)(AVFilterLink *link);
361
362 /**
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363 * Frame request callback. A call to this should result in at least one
364 * frame being output over the given link. This should return zero on
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365 * success, and another value on error.
366 *
367 * Output video pads only.
a5cbb2f4 368 */
63f64e6f 369 int (*request_frame)(AVFilterLink *link);
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370
371 /**
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372 * Link configuration callback.
373 *
374 * For output pads, this should set the link properties such as
38efe768 375 * width/height. This should NOT set the format property - that is
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376 * negotiated between filters by the filter system using the
377 * query_formats() callback before this function is called.
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378 *
379 * For input pads, this should check the properties of the link, and update
380 * the filter's internal state as necessary.
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381 *
382 * For both input and output filters, this should return zero on success,
383 * and another value on error.
a5cbb2f4 384 */
d3e57c15 385 int (*config_props)(AVFilterLink *link);
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386};
387
2b187df9 388/** default handler for start_frame() for video inputs */
a5cbb2f4 389void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
b9609848 390/** default handler for draw_slice() for video inputs */
a13a5437 391void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
2b187df9 392/** default handler for end_frame() for video inputs */
a5cbb2f4 393void avfilter_default_end_frame(AVFilterLink *link);
2b187df9 394/** default handler for config_props() for video outputs */
901e6b39 395int avfilter_default_config_output_link(AVFilterLink *link);
2b187df9 396/** default handler for config_props() for video inputs */
85322466 397int avfilter_default_config_input_link (AVFilterLink *link);
2b187df9 398/** default handler for get_video_buffer() for video inputs */
901e6b39 399AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
0eb4ff9e 400 int perms, int w, int h);
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401/**
402 * A helper for query_formats() which sets all links to the same list of
403 * formats. If there are no links hooked to this filter, the list of formats is
404 * freed.
405 */
406void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
407/** Default handler for query_formats() */
408int avfilter_default_query_formats(AVFilterContext *ctx);
a5cbb2f4 409
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410/** start_frame() handler for filters which simply pass video along */
411void avfilter_null_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
412
413/** draw_slice() handler for filters which simply pass video along */
414void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
415
416/** end_frame() handler for filters which simply pass video along */
417void avfilter_null_end_frame(AVFilterLink *link);
418
419/** get_video_buffer() handler for filters which simply pass video along */
420AVFilterPicRef *avfilter_null_get_video_buffer(AVFilterLink *link,
421 int perms, int w, int h);
422
13ff8fd0 423/**
38efe768 424 * Filter definition. This defines the pads a filter contains, and all the
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425 * callback functions used to interact with the filter.
426 */
243110f9 427typedef struct AVFilter
a5cbb2f4 428{
2844dd39 429 const char *name; ///< filter name
a5cbb2f4 430
13ff8fd0 431 int priv_size; ///< size of private data to allocate for the filter
a5cbb2f4 432
4d96a914 433 /**
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434 * Filter initialization function. Args contains the user-supplied
435 * parameters. FIXME: maybe an AVOption-based system would be better?
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436 * opaque is data provided by the code requesting creation of the filter,
437 * and is used to pass data to the filter.
4d96a914 438 */
95bcf498 439 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
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440
441 /**
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442 * Filter uninitialization function. Should deallocate any memory held
443 * by the filter, release any picture references, etc. This does not need
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444 * to deallocate the AVFilterContext->priv memory itself.
445 */
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446 void (*uninit)(AVFilterContext *ctx);
447
35f3fdf4 448 /**
c4d2e41c 449 * Queries formats supported by the filter and its pads, and sets the
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450 * in_formats for links connected to its output pads, and out_formats
451 * for links connected to its input pads.
452 *
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453 * @return zero on success, a negative value corresponding to an
454 * AVERROR code otherwise
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455 */
456 int (*query_formats)(AVFilterContext *);
457
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458 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
459 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
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460
461 /**
462 * A description for the filter. You should use the
463 * NULL_IF_CONFIG_SMALL() macro to define it.
464 */
465 const char *description;
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466} AVFilter;
467
13ff8fd0 468/** An instance of a filter */
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469struct AVFilterContext
470{
d42a814e 471 const AVClass *av_class; ///< needed for av_log()
a5cbb2f4 472
664f6595 473 AVFilter *filter; ///< the AVFilter of which this is an instance
a5cbb2f4 474
13ff8fd0 475 char *name; ///< name of this filter instance
dcea2482 476
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477 unsigned input_count; ///< number of input pads
478 AVFilterPad *input_pads; ///< array of input pads
479 AVFilterLink **inputs; ///< array of pointers to input links
25f8e601 480
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481 unsigned output_count; ///< number of output pads
482 AVFilterPad *output_pads; ///< array of output pads
483 AVFilterLink **outputs; ///< array of pointers to output links
a5cbb2f4 484
13ff8fd0 485 void *priv; ///< private data for use by the filter
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486};
487
13ff8fd0 488/**
38efe768 489 * A link between two filters. This contains pointers to the source and
f4433de9 490 * destination filters between which this link exists, and the indexes of
38efe768 491 * the pads involved. In addition, this link also contains the parameters
13ff8fd0 492 * which have been negotiated and agreed upon between the filter, such as
2b187df9 493 * image dimensions, format, etc.
13ff8fd0 494 */
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495struct AVFilterLink
496{
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497 AVFilterContext *src; ///< source filter
498 unsigned int srcpad; ///< index of the output pad on the source filter
a5cbb2f4 499
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500 AVFilterContext *dst; ///< dest filter
501 unsigned int dstpad; ///< index of the input pad on the dest filter
a5cbb2f4 502
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503 /** stage of the initialization of the link properties (dimensions, etc) */
504 enum {
505 AVLINK_UNINIT = 0, ///< not started
506 AVLINK_STARTINIT, ///< started, but incomplete
507 AVLINK_INIT ///< complete
508 } init_state;
509
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510 int w; ///< agreed upon image width
511 int h; ///< agreed upon image height
512 enum PixelFormat format; ///< agreed upon image colorspace
a5cbb2f4 513
60bf6ce3 514 /**
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515 * Lists of formats supported by the input and output filters respectively.
516 * These lists are used for negotiating the format to actually be used,
517 * which will be loaded into the format member, above, when chosen.
518 */
519 AVFilterFormats *in_formats;
520 AVFilterFormats *out_formats;
521
522 /**
60bf6ce3 523 * The picture reference currently being sent across the link by the source
38efe768 524 * filter. This is used internally by the filter system to allow
664f6595 525 * automatic copying of pictures which do not have sufficient permissions
38efe768 526 * for the destination. This should not be accessed directly by the
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527 * filters.
528 */
529 AVFilterPicRef *srcpic;
530
a5cbb2f4 531 AVFilterPicRef *cur_pic;
462f57db 532 AVFilterPicRef *outpic;
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533};
534
13ff8fd0 535/**
49bd8e4b 536 * Link two filters together.
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537 * @param src the source filter
538 * @param srcpad index of the output pad on the source filter
539 * @param dst the destination filter
540 * @param dstpad index of the input pad on the destination filter
541 * @return zero on success
13ff8fd0 542 */
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543int avfilter_link(AVFilterContext *src, unsigned srcpad,
544 AVFilterContext *dst, unsigned dstpad);
545
13ff8fd0 546/**
49bd8e4b 547 * Negotiate the colorspace, dimensions, etc of all inputs to a filter.
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548 * @param filter the filter to negotiate the properties for its inputs
549 * @return zero on successful negotiation
13ff8fd0 550 */
24c4eff6 551int avfilter_config_links(AVFilterContext *filter);
85322466 552
13ff8fd0 553/**
49bd8e4b 554 * Request a picture buffer with a specific set of permissions.
664f6595 555 * @param link the output link to the filter from which the picture will
13ff8fd0 556 * be requested
664f6595 557 * @param perms the required access permissions
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558 * @param w the minimum width of the buffer to allocate
559 * @param h the minimum height of the buffer to allocate
38efe768 560 * @return A reference to the picture. This must be unreferenced with
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561 * avfilter_unref_pic when you are finished with it.
562 */
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563AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
564 int w, int h);
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565
566/**
49bd8e4b 567 * Request an input frame from the filter at the other end of the link.
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568 * @param link the input link
569 * @return zero on success
13ff8fd0 570 */
0155b1a1 571int avfilter_request_frame(AVFilterLink *link);
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572
573/**
49bd8e4b 574 * Poll a frame from the filter chain.
b04c740a 575 * @param link the input link
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576 * @return the number of immediately available frames, a negative
577 * number in case of error
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578 */
579int avfilter_poll_frame(AVFilterLink *link);
580
581/**
49bd8e4b 582 * Notifie the next filter of the start of a frame.
664f6595 583 * @param link the output link the frame will be sent over
38efe768 584 * @param picref A reference to the frame about to be sent. The data for this
13ff8fd0 585 * frame need only be valid once draw_slice() is called for that
38efe768 586 * portion. The receiving filter will free this reference when
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587 * it no longer needs it.
588 */
a5cbb2f4 589void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
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590
591/**
49bd8e4b 592 * Notifie the next filter that the current frame has finished.
664f6595 593 * @param link the output link the frame was sent over
13ff8fd0 594 */
a5cbb2f4 595void avfilter_end_frame(AVFilterLink *link);
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596
597/**
49bd8e4b 598 * Send a slice to the next filter.
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599 *
600 * Slices have to be provided in sequential order, either in
601 * top-bottom or bottom-top order. If slices are provided in
602 * non-sequential order the behavior of the function is undefined.
603 *
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604 * @param link the output link over which the frame is being sent
605 * @param y offset in pixels from the top of the image for this slice
606 * @param h height of this slice in pixels
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607 * @param slice_dir the assumed direction for sending slices,
608 * from the top slice to the bottom slice if the value is 1,
609 * from the bottom slice to the top slice if the value is -1,
610 * for other values the behavior of the function is undefined.
13ff8fd0 611 */
a13a5437 612void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
a5cbb2f4 613
49bd8e4b 614/** Initialize the filter system. Register all builtin filters. */
11de6cac 615void avfilter_register_all(void);
e4152452 616
49bd8e4b 617/** Uninitialize the filter system. Unregister all filters. */
a5cbb2f4 618void avfilter_uninit(void);
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619
620/**
49bd8e4b 621 * Register a filter. This is only needed if you plan to use
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622 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
623 * filter can still by instantiated with avfilter_open even if it is not
624 * registered.
664f6595 625 * @param filter the filter to register
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626 * @return 0 if the registration was succesfull, a negative value
627 * otherwise
13ff8fd0 628 */
86a60fa1 629int avfilter_register(AVFilter *filter);
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630
631/**
49bd8e4b 632 * Get a filter definition matching the given name.
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633 * @param name the filter name to find
634 * @return the filter definition, if any matching one is registered.
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635 * NULL if none found.
636 */
2844dd39 637AVFilter *avfilter_get_by_name(const char *name);
a5cbb2f4 638
13ff8fd0 639/**
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640 * If filter is NULL, returns a pointer to the first registered filter pointer,
641 * if filter is non-NULL, returns the next pointer after filter.
642 * If the returned pointer points to NULL, the last registered filter
643 * was already reached.
644 */
645AVFilter **av_filter_next(AVFilter **filter);
646
647/**
49bd8e4b 648 * Create a filter instance.
664f6595 649 * @param filter the filter to create an instance of
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650 * @param inst_name Name to give to the new instance. Can be NULL for none.
651 * @return Pointer to the new instance on success. NULL on failure.
13ff8fd0 652 */
2844dd39 653AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
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654
655/**
49bd8e4b 656 * Initialize a filter.
664f6595 657 * @param filter the filter to initialize
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658 * @param args A string of parameters to use when initializing the filter.
659 * The format and meaning of this string varies by filter.
38efe768 660 * @param opaque Any extra non-string data needed by the filter. The meaning
13ff8fd0 661 * of this parameter varies by filter.
664f6595 662 * @return zero on success
13ff8fd0 663 */
6e365c57 664int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
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665
666/**
49bd8e4b 667 * Destroy a filter.
664f6595 668 * @param filter the filter to destroy
13ff8fd0 669 */
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670void avfilter_destroy(AVFilterContext *filter);
671
13ff8fd0 672/**
49bd8e4b 673 * Insert a filter in the middle of an existing link.
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674 * @param link the link into which the filter should be inserted
675 * @param filt the filter to be inserted
676 * @param in the input pad on the filter to connect
677 * @param out the output pad on the filter to connect
678 * @return zero on success
13ff8fd0 679 */
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680int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
681 unsigned in, unsigned out);
d3e57c15 682
a9c81431 683/**
49bd8e4b 684 * Insert a new pad.
38efe768 685 * @param idx Insertion point. Pad is inserted at the end if this point
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686 * is beyond the end of the list of pads.
687 * @param count Pointer to the number of pads in the list
688 * @param padidx_off Offset within an AVFilterLink structure to the element
689 * to increment when inserting a new pad causes link
690 * numbering to change
691 * @param pads Pointer to the pointer to the beginning of the list of pads
692 * @param links Pointer to the pointer to the beginning of the list of links
693 * @param newpad The new pad to add. A copy is made when adding.
694 */
695void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
696 AVFilterPad **pads, AVFilterLink ***links,
697 AVFilterPad *newpad);
698
49bd8e4b 699/** Insert a new input pad for the filter. */
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700static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
701 AVFilterPad *p)
702{
703 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
704 &f->input_pads, &f->inputs, p);
705}
706
49bd8e4b 707/** Insert a new output pad for the filter. */
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708static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
709 AVFilterPad *p)
710{
711 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
712 &f->output_pads, &f->outputs, p);
713}
714
98790382 715#endif /* AVFILTER_AVFILTER_H */