Set the correct type for the output links.
[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
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28#define LIBAVFILTER_VERSION_MINOR 35
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
540f1c7b 42/**
49bd8e4b 43 * Return the LIBAVFILTER_VERSION_INT constant.
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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
ecc8dada 65 * AVFilterBufferRef structure below.
a5cbb2f4 66 */
f607cc18 67typedef struct AVFilterBuffer {
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68 uint8_t *data[8]; ///< buffer data for each plane/channel
69 int linesize[8]; ///< number of bytes per line
a5cbb2f4 70
32d7bcd4 71 unsigned refcount; ///< number of references to this buffer
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72
73 /** private data to be used by a custom free function */
a5cbb2f4 74 void *priv;
13ff8fd0 75 /**
32d7bcd4 76 * A pointer to the function to deallocate this buffer if the default
38efe768 77 * function is not sufficient. This could, for example, add the memory
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78 * back into a memory pool to be reused later without the overhead of
79 * reallocating it from scratch.
80 */
32d7bcd4 81 void (*free)(struct AVFilterBuffer *buf);
f0d77b20 82} AVFilterBuffer;
a5cbb2f4 83
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84#define AV_PERM_READ 0x01 ///< can read from the buffer
85#define AV_PERM_WRITE 0x02 ///< can write to the buffer
86#define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
87#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
88#define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
89
a5cbb2f4 90/**
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91 * Video specific properties in a reference to an AVFilterBuffer. Since
92 * AVFilterBufferRef is common to different media formats, video specific
93 * per reference properties must be separated out.
94 */
f607cc18 95typedef struct AVFilterBufferRefVideoProps {
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96 int w; ///< image width
97 int h; ///< image height
98 AVRational pixel_aspect; ///< pixel aspect ratio
99 int interlaced; ///< is frame interlaced
100 int top_field_first; ///< field order
101} AVFilterBufferRefVideoProps;
102
103/**
f0d77b20 104 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
7fce481a 105 * a buffer to, for example, crop image without any memcpy, the buffer origin
38efe768 106 * and dimensions are per-reference properties. Linesize is also useful for
bbf42679 107 * image flipping, frame to field filters, etc, and so is also per-reference.
a5cbb2f4 108 *
1a18860a 109 * TODO: add anything necessary for frame reordering
a5cbb2f4 110 */
f607cc18 111typedef struct AVFilterBufferRef {
7fce481a 112 AVFilterBuffer *buf; ///< the buffer that this is a reference to
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113 uint8_t *data[8]; ///< picture data for each plane
114 int linesize[8]; ///< number of bytes per line
d54e0948 115 int format; ///< media format
a5cbb2f4 116
056f0431 117 int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
5bb5c1dc 118 int64_t pos; ///< byte position in stream, -1 if unknown
1a18860a 119
ff5f1be0 120 int perms; ///< permissions, see the AV_PERM_* flags
efdc74ef 121
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122 enum AVMediaType type; ///< media type of buffer data
123 AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
ecc8dada 124} AVFilterBufferRef;
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125
126/**
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127 * Copy properties of src to dst, without copying the actual video
128 * data.
129 */
7fce481a 130static inline void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src)
4d508e4d 131{
cc80caff 132 // copy common properties
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133 dst->pts = src->pts;
134 dst->pos = src->pos;
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135
136 switch (src->type) {
137 case AVMEDIA_TYPE_VIDEO: *dst->video = *src->video; break;
138 }
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139}
140
141/**
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142 * Add a new reference to a buffer.
143 * @param ref an existing reference to the buffer
664f6595 144 * @param pmask a bitmask containing the allowable permissions in the new
13ff8fd0 145 * reference
7fce481a 146 * @return a new reference to the buffer with the same properties as the
13ff8fd0 147 * old, excluding any permissions denied by pmask
a5cbb2f4 148 */
7fce481a 149AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
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150
151/**
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152 * Remove a reference to a buffer. If this is the last reference to the
153 * buffer, the buffer itself is also automatically freed.
154 * @param ref reference to the buffer
a5cbb2f4 155 */
7fce481a 156void avfilter_unref_buffer(AVFilterBufferRef *ref);
a5cbb2f4 157
13ff8fd0 158/**
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159 * A list of supported formats for one end of a filter link. This is used
160 * during the format negotiation process to try to pick the best format to
161 * use to minimize the number of necessary conversions. Each filter gives a
162 * list of the formats supported by each input and output pad. The list
163 * given for each pad need not be distinct - they may be references to the
164 * same list of formats, as is often the case when a filter supports multiple
42f72a3a 165 * formats, but will always output the same format as it is given in input.
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166 *
167 * In this way, a list of possible input formats and a list of possible
168 * output formats are associated with each link. When a set of formats is
169 * negotiated over a link, the input and output lists are merged to form a
170 * new list containing only the common elements of each list. In the case
171 * that there were no common elements, a format conversion is necessary.
172 * Otherwise, the lists are merged, and all other links which reference
173 * either of the format lists involved in the merge are also affected.
174 *
175 * For example, consider the filter chain:
176 * filter (a) --> (b) filter (b) --> (c) filter
177 *
178 * where the letters in parenthesis indicate a list of formats supported on
179 * the input or output of the link. Suppose the lists are as follows:
180 * (a) = {A, B}
181 * (b) = {A, B, C}
182 * (c) = {B, C}
183 *
184 * First, the first link's lists are merged, yielding:
185 * filter (a) --> (a) filter (a) --> (c) filter
186 *
187 * Notice that format list (b) now refers to the same list as filter list (a).
188 * Next, the lists for the second link are merged, yielding:
189 * filter (a) --> (a) filter (a) --> (a) filter
190 *
191 * where (a) = {B}.
192 *
193 * Unfortunately, when the format lists at the two ends of a link are merged,
194 * we must ensure that all links which reference either pre-merge format list
195 * get updated as well. Therefore, we have the format list structure store a
196 * pointer to each of the pointers to itself.
197 */
f607cc18 198typedef struct AVFilterFormats {
35f3fdf4 199 unsigned format_count; ///< number of formats
bdab614b 200 int *formats; ///< list of media formats
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201
202 unsigned refcount; ///< number of references to this list
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203 struct AVFilterFormats ***refs; ///< references to this list
204} AVFilterFormats;;
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205
206/**
49bd8e4b 207 * Create a list of supported formats. This is intended for use in
f6a1fa85 208 * AVFilter->query_formats().
bdab614b 209 * @param fmts list of media formats, terminated by -1
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210 * @return the format list, with no existing references
211 */
bdab614b 212AVFilterFormats *avfilter_make_format_list(const int *fmts);
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213
214/**
bdab614b 215 * Add fmt to the list of media formats contained in *avff.
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216 * If *avff is NULL the function allocates the filter formats struct
217 * and puts its pointer in *avff.
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218 *
219 * @return a non negative value in case of success, or a negative
220 * value corresponding to an AVERROR code in case of error
221 */
bdab614b 222int avfilter_add_format(AVFilterFormats **avff, int fmt);
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223
224/**
bdab614b 225 * Return a list of all formats supported by FFmpeg for the given media type.
35f3fdf4 226 */
bdab614b 227AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
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228
229/**
49bd8e4b 230 * Return a format list which contains the intersection of the formats of
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231 * a and b. Also, all the references of a, all the references of b, and
232 * a and b themselves will be deallocated.
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233 *
234 * If a and b do not share any common formats, neither is modified, and NULL
235 * is returned.
236 */
237AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
238
09b63a42 239/**
49bd8e4b 240 * Add *ref as a new reference to formats.
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241 * That is the pointers will point like in the ascii art below:
242 * ________
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243 * |formats |<--------.
244 * | ____ | ____|___________________
245 * | |refs| | | __|_
246 * | |* * | | | | | | AVFilterLink
09b63a42 247 * | |* *--------->|*ref|
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248 * | |____| | | |____|
249 * |________| |________________________
09b63a42 250 */
a27c8d5f 251void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
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252
253/**
49bd8e4b 254 * If *ref is non-NULL, remove *ref as a reference to the format list
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255 * it currently points to, deallocates that list if this was the last
256 * reference, and sets *ref to NULL.
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257 *
258 * Before After
259 * ________ ________ NULL
260 * |formats |<--------. |formats | ^
261 * | ____ | ____|________________ | ____ | ____|________________
262 * | |refs| | | __|_ | |refs| | | __|_
263 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
264 * | |* *--------->|*ref| | |* | | | |*ref|
265 * | |____| | | |____| | |____| | | |____|
266 * |________| |_____________________ |________| |_____________________
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267 */
268void avfilter_formats_unref(AVFilterFormats **ref);
269
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270/**
271 *
272 * Before After
273 * ________ ________
a27c8d5f 274 * |formats |<---------. |formats |<---------.
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275 * | ____ | ___|___ | ____ | ___|___
276 * | |refs| | | | | | |refs| | | | | NULL
277 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
278 * | |* * | | |_______| | |* * | | |_______| ___|___
279 * | |____| | | |____| | | | |
280 * |________| |________| |*oldref|
281 * |_______|
282 */
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283void avfilter_formats_changeref(AVFilterFormats **oldref,
284 AVFilterFormats **newref);
285
35f3fdf4 286/**
664f6595 287 * A filter pad used for either input or output.
13ff8fd0 288 */
f607cc18 289struct AVFilterPad {
a5cbb2f4 290 /**
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291 * Pad name. The name is unique among inputs and among outputs, but an
292 * input may have the same name as an output. This may be NULL if this
13ff8fd0 293 * pad has no need to ever be referenced by name.
a5cbb2f4 294 */
2844dd39 295 const char *name;
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296
297 /**
38efe768 298 * AVFilterPad type. Only video supported now, hopefully someone will
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299 * add audio in the future.
300 */
72415b2a 301 enum AVMediaType type;
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302
303 /**
38efe768 304 * Minimum required permissions on incoming buffers. Any buffer with
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305 * insufficient permissions will be automatically copied by the filter
306 * system to a new buffer which provides the needed access permissions.
307 *
308 * Input pads only.
309 */
310 int min_perms;
311
312 /**
38efe768 313 * Permissions which are not accepted on incoming buffers. Any buffer
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314 * which has any of these permissions set will be automatically copied
315 * by the filter system to a new buffer which does not have those
38efe768 316 * permissions. This can be used to easily disallow buffers with
9ce95f27 317 * AV_PERM_REUSE.
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318 *
319 * Input pads only.
320 */
321 int rej_perms;
322
323 /**
38efe768 324 * Callback called before passing the first slice of a new frame. If
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325 * NULL, the filter layer will default to storing a reference to the
326 * picture inside the link structure.
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327 *
328 * Input video pads only.
a5cbb2f4 329 */
ecc8dada 330 void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
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331
332 /**
38efe768 333 * Callback function to get a buffer. If NULL, the filter system will
da23d424 334 * use avfilter_default_get_video_buffer().
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335 *
336 * Input video pads only.
a5cbb2f4 337 */
ecc8dada 338 AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
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339
340 /**
38efe768 341 * Callback called after the slices of a frame are completely sent. If
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342 * NULL, the filter layer will default to releasing the reference stored
343 * in the link structure during start_frame().
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344 *
345 * Input video pads only.
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346 */
347 void (*end_frame)(AVFilterLink *link);
348
349 /**
38efe768 350 * Slice drawing callback. This is where a filter receives video data
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351 * and should do its processing.
352 *
353 * Input video pads only.
a5cbb2f4 354 */
a13a5437 355 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
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356
357 /**
38efe768 358 * Frame poll callback. This returns the number of immediately available
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359 * frames. It should return a positive value if the next request_frame()
360 * is guaranteed to return one frame (with no delay).
361 *
362 * Defaults to just calling the source poll_frame() method.
363 *
364 * Output video pads only.
365 */
366 int (*poll_frame)(AVFilterLink *link);
367
368 /**
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369 * Frame request callback. A call to this should result in at least one
370 * frame being output over the given link. This should return zero on
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371 * success, and another value on error.
372 *
373 * Output video pads only.
a5cbb2f4 374 */
63f64e6f 375 int (*request_frame)(AVFilterLink *link);
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376
377 /**
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378 * Link configuration callback.
379 *
380 * For output pads, this should set the link properties such as
38efe768 381 * width/height. This should NOT set the format property - that is
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382 * negotiated between filters by the filter system using the
383 * query_formats() callback before this function is called.
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384 *
385 * For input pads, this should check the properties of the link, and update
386 * the filter's internal state as necessary.
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387 *
388 * For both input and output filters, this should return zero on success,
389 * and another value on error.
a5cbb2f4 390 */
d3e57c15 391 int (*config_props)(AVFilterLink *link);
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392};
393
2b187df9 394/** default handler for start_frame() for video inputs */
ecc8dada 395void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
a4fb0ada 396
b9609848 397/** default handler for draw_slice() for video inputs */
a13a5437 398void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
a4fb0ada 399
2b187df9 400/** default handler for end_frame() for video inputs */
a5cbb2f4 401void avfilter_default_end_frame(AVFilterLink *link);
a4fb0ada 402
2b187df9 403/** default handler for config_props() for video outputs */
901e6b39 404int avfilter_default_config_output_link(AVFilterLink *link);
a4fb0ada 405
2b187df9 406/** default handler for config_props() for video inputs */
85322466 407int avfilter_default_config_input_link (AVFilterLink *link);
a4fb0ada 408
2b187df9 409/** default handler for get_video_buffer() for video inputs */
ecc8dada 410AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,
a4fb0ada 411 int perms, int w, int h);
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412/**
413 * A helper for query_formats() which sets all links to the same list of
414 * formats. If there are no links hooked to this filter, the list of formats is
415 * freed.
416 */
417void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
a4fb0ada 418
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419/** Default handler for query_formats() */
420int avfilter_default_query_formats(AVFilterContext *ctx);
a5cbb2f4 421
91d1c741 422/** start_frame() handler for filters which simply pass video along */
ecc8dada 423void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
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424
425/** draw_slice() handler for filters which simply pass video along */
426void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
427
428/** end_frame() handler for filters which simply pass video along */
429void avfilter_null_end_frame(AVFilterLink *link);
430
431/** get_video_buffer() handler for filters which simply pass video along */
ecc8dada 432AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link,
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433 int perms, int w, int h);
434
13ff8fd0 435/**
38efe768 436 * Filter definition. This defines the pads a filter contains, and all the
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437 * callback functions used to interact with the filter.
438 */
f607cc18 439typedef struct AVFilter {
2844dd39 440 const char *name; ///< filter name
a5cbb2f4 441
13ff8fd0 442 int priv_size; ///< size of private data to allocate for the filter
a5cbb2f4 443
4d96a914 444 /**
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445 * Filter initialization function. Args contains the user-supplied
446 * parameters. FIXME: maybe an AVOption-based system would be better?
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447 * opaque is data provided by the code requesting creation of the filter,
448 * and is used to pass data to the filter.
4d96a914 449 */
95bcf498 450 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
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451
452 /**
38efe768 453 * Filter uninitialization function. Should deallocate any memory held
7fce481a 454 * by the filter, release any buffer references, etc. This does not need
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455 * to deallocate the AVFilterContext->priv memory itself.
456 */
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457 void (*uninit)(AVFilterContext *ctx);
458
35f3fdf4 459 /**
c4d2e41c 460 * Queries formats supported by the filter and its pads, and sets the
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461 * in_formats for links connected to its output pads, and out_formats
462 * for links connected to its input pads.
463 *
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464 * @return zero on success, a negative value corresponding to an
465 * AVERROR code otherwise
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466 */
467 int (*query_formats)(AVFilterContext *);
468
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469 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
470 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
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471
472 /**
473 * A description for the filter. You should use the
474 * NULL_IF_CONFIG_SMALL() macro to define it.
475 */
476 const char *description;
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477} AVFilter;
478
13ff8fd0 479/** An instance of a filter */
f607cc18 480struct AVFilterContext {
d42a814e 481 const AVClass *av_class; ///< needed for av_log()
a5cbb2f4 482
664f6595 483 AVFilter *filter; ///< the AVFilter of which this is an instance
a5cbb2f4 484
13ff8fd0 485 char *name; ///< name of this filter instance
dcea2482 486
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487 unsigned input_count; ///< number of input pads
488 AVFilterPad *input_pads; ///< array of input pads
489 AVFilterLink **inputs; ///< array of pointers to input links
25f8e601 490
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491 unsigned output_count; ///< number of output pads
492 AVFilterPad *output_pads; ///< array of output pads
493 AVFilterLink **outputs; ///< array of pointers to output links
a5cbb2f4 494
13ff8fd0 495 void *priv; ///< private data for use by the filter
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496};
497
13ff8fd0 498/**
38efe768 499 * A link between two filters. This contains pointers to the source and
f4433de9 500 * destination filters between which this link exists, and the indexes of
38efe768 501 * the pads involved. In addition, this link also contains the parameters
13ff8fd0 502 * which have been negotiated and agreed upon between the filter, such as
2b187df9 503 * image dimensions, format, etc.
13ff8fd0 504 */
f607cc18 505struct AVFilterLink {
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506 AVFilterContext *src; ///< source filter
507 unsigned int srcpad; ///< index of the output pad on the source filter
a5cbb2f4 508
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509 AVFilterContext *dst; ///< dest filter
510 unsigned int dstpad; ///< index of the input pad on the dest filter
a5cbb2f4 511
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512 /** stage of the initialization of the link properties (dimensions, etc) */
513 enum {
514 AVLINK_UNINIT = 0, ///< not started
515 AVLINK_STARTINIT, ///< started, but incomplete
516 AVLINK_INIT ///< complete
517 } init_state;
518
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519 enum AVMediaType type; ///< filter media type
520
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521 int w; ///< agreed upon image width
522 int h; ///< agreed upon image height
bdab614b 523 int format; ///< agreed upon media format
a5cbb2f4 524
60bf6ce3 525 /**
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526 * Lists of formats supported by the input and output filters respectively.
527 * These lists are used for negotiating the format to actually be used,
528 * which will be loaded into the format member, above, when chosen.
529 */
530 AVFilterFormats *in_formats;
531 AVFilterFormats *out_formats;
532
533 /**
7fce481a 534 * The buffer reference currently being sent across the link by the source
38efe768 535 * filter. This is used internally by the filter system to allow
7fce481a 536 * automatic copying of buffers which do not have sufficient permissions
38efe768 537 * for the destination. This should not be accessed directly by the
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538 * filters.
539 */
5d4890d7 540 AVFilterBufferRef *src_buf;
60bf6ce3 541
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542 AVFilterBufferRef *cur_buf;
543 AVFilterBufferRef *out_buf;
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544};
545
13ff8fd0 546/**
49bd8e4b 547 * Link two filters together.
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548 * @param src the source filter
549 * @param srcpad index of the output pad on the source filter
550 * @param dst the destination filter
551 * @param dstpad index of the input pad on the destination filter
552 * @return zero on success
13ff8fd0 553 */
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554int avfilter_link(AVFilterContext *src, unsigned srcpad,
555 AVFilterContext *dst, unsigned dstpad);
556
13ff8fd0 557/**
bdab614b 558 * Negotiate the media format, dimensions, etc of all inputs to a filter.
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559 * @param filter the filter to negotiate the properties for its inputs
560 * @return zero on successful negotiation
13ff8fd0 561 */
24c4eff6 562int avfilter_config_links(AVFilterContext *filter);
85322466 563
13ff8fd0 564/**
49bd8e4b 565 * Request a picture buffer with a specific set of permissions.
7fce481a 566 * @param link the output link to the filter from which the buffer will
13ff8fd0 567 * be requested
664f6595 568 * @param perms the required access permissions
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569 * @param w the minimum width of the buffer to allocate
570 * @param h the minimum height of the buffer to allocate
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571 * @return A reference to the buffer. This must be unreferenced with
572 * avfilter_unref_buffer when you are finished with it.
13ff8fd0 573 */
ecc8dada 574AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
0eb4ff9e 575 int w, int h);
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576
577/**
49bd8e4b 578 * Request an input frame from the filter at the other end of the link.
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579 * @param link the input link
580 * @return zero on success
13ff8fd0 581 */
0155b1a1 582int avfilter_request_frame(AVFilterLink *link);
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583
584/**
49bd8e4b 585 * Poll a frame from the filter chain.
b04c740a 586 * @param link the input link
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587 * @return the number of immediately available frames, a negative
588 * number in case of error
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589 */
590int avfilter_poll_frame(AVFilterLink *link);
591
592/**
49bd8e4b 593 * Notifie the next filter of the start of a frame.
664f6595 594 * @param link the output link the frame will be sent over
38efe768 595 * @param picref A reference to the frame about to be sent. The data for this
13ff8fd0 596 * frame need only be valid once draw_slice() is called for that
38efe768 597 * portion. The receiving filter will free this reference when
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598 * it no longer needs it.
599 */
ecc8dada 600void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
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601
602/**
49bd8e4b 603 * Notifie the next filter that the current frame has finished.
664f6595 604 * @param link the output link the frame was sent over
13ff8fd0 605 */
a5cbb2f4 606void avfilter_end_frame(AVFilterLink *link);
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607
608/**
49bd8e4b 609 * Send a slice to the next filter.
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610 *
611 * Slices have to be provided in sequential order, either in
612 * top-bottom or bottom-top order. If slices are provided in
613 * non-sequential order the behavior of the function is undefined.
614 *
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615 * @param link the output link over which the frame is being sent
616 * @param y offset in pixels from the top of the image for this slice
617 * @param h height of this slice in pixels
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618 * @param slice_dir the assumed direction for sending slices,
619 * from the top slice to the bottom slice if the value is 1,
620 * from the bottom slice to the top slice if the value is -1,
621 * for other values the behavior of the function is undefined.
13ff8fd0 622 */
a13a5437 623void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
a5cbb2f4 624
49bd8e4b 625/** Initialize the filter system. Register all builtin filters. */
11de6cac 626void avfilter_register_all(void);
e4152452 627
49bd8e4b 628/** Uninitialize the filter system. Unregister all filters. */
a5cbb2f4 629void avfilter_uninit(void);
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630
631/**
49bd8e4b 632 * Register a filter. This is only needed if you plan to use
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633 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
634 * filter can still by instantiated with avfilter_open even if it is not
635 * registered.
664f6595 636 * @param filter the filter to register
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637 * @return 0 if the registration was succesfull, a negative value
638 * otherwise
13ff8fd0 639 */
86a60fa1 640int avfilter_register(AVFilter *filter);
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641
642/**
49bd8e4b 643 * Get a filter definition matching the given name.
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644 * @param name the filter name to find
645 * @return the filter definition, if any matching one is registered.
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646 * NULL if none found.
647 */
2844dd39 648AVFilter *avfilter_get_by_name(const char *name);
a5cbb2f4 649
13ff8fd0 650/**
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651 * If filter is NULL, returns a pointer to the first registered filter pointer,
652 * if filter is non-NULL, returns the next pointer after filter.
653 * If the returned pointer points to NULL, the last registered filter
654 * was already reached.
655 */
656AVFilter **av_filter_next(AVFilter **filter);
657
658/**
49bd8e4b 659 * Create a filter instance.
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660 *
661 * @param filter_ctx put here a pointer to the created filter context
662 * on success, NULL on failure
664f6595 663 * @param filter the filter to create an instance of
38efe768 664 * @param inst_name Name to give to the new instance. Can be NULL for none.
84c03869 665 * @return >= 0 in case of success, a negative error code otherwise
13ff8fd0 666 */
84c03869 667int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
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668
669/**
49bd8e4b 670 * Initialize a filter.
664f6595 671 * @param filter the filter to initialize
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672 * @param args A string of parameters to use when initializing the filter.
673 * The format and meaning of this string varies by filter.
38efe768 674 * @param opaque Any extra non-string data needed by the filter. The meaning
13ff8fd0 675 * of this parameter varies by filter.
664f6595 676 * @return zero on success
13ff8fd0 677 */
6e365c57 678int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
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679
680/**
49bd8e4b 681 * Destroy a filter.
664f6595 682 * @param filter the filter to destroy
13ff8fd0 683 */
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684void avfilter_destroy(AVFilterContext *filter);
685
13ff8fd0 686/**
49bd8e4b 687 * Insert a filter in the middle of an existing link.
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688 * @param link the link into which the filter should be inserted
689 * @param filt the filter to be inserted
690 * @param in the input pad on the filter to connect
691 * @param out the output pad on the filter to connect
692 * @return zero on success
13ff8fd0 693 */
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694int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
695 unsigned in, unsigned out);
d3e57c15 696
a9c81431 697/**
49bd8e4b 698 * Insert a new pad.
38efe768 699 * @param idx Insertion point. Pad is inserted at the end if this point
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700 * is beyond the end of the list of pads.
701 * @param count Pointer to the number of pads in the list
702 * @param padidx_off Offset within an AVFilterLink structure to the element
703 * to increment when inserting a new pad causes link
704 * numbering to change
705 * @param pads Pointer to the pointer to the beginning of the list of pads
706 * @param links Pointer to the pointer to the beginning of the list of links
707 * @param newpad The new pad to add. A copy is made when adding.
708 */
709void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
710 AVFilterPad **pads, AVFilterLink ***links,
711 AVFilterPad *newpad);
712
49bd8e4b 713/** Insert a new input pad for the filter. */
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714static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
715 AVFilterPad *p)
716{
717 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
718 &f->input_pads, &f->inputs, p);
719}
720
49bd8e4b 721/** Insert a new output pad for the filter. */
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722static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
723 AVFilterPad *p)
724{
725 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
726 &f->output_pads, &f->outputs, p);
727}
728
98790382 729#endif /* AVFILTER_AVFILTER_H */