Implement null video sink.
[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
006aa1a4 28#define LIBAVFILTER_VERSION_MINOR 17
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
1a18860a 108
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109 AVRational pixel_aspect; ///< pixel aspect ratio
110
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111 int perms; ///< permissions
112#define AV_PERM_READ 0x01 ///< can read from the buffer
113#define AV_PERM_WRITE 0x02 ///< can write to the buffer
114#define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
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115#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
116#define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
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117} AVFilterPicRef;
118
119/**
c5c6f626 120 * Adds a new reference to a picture.
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121 * @param ref an existing reference to the picture
122 * @param pmask a bitmask containing the allowable permissions in the new
13ff8fd0 123 * reference
664f6595 124 * @return a new reference to the picture with the same properties as the
13ff8fd0 125 * old, excluding any permissions denied by pmask
a5cbb2f4 126 */
16415eaf 127AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
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128
129/**
c5c6f626 130 * Removes a reference to a picture. If this is the last reference to the
a5cbb2f4 131 * picture, the picture itself is also automatically freed.
664f6595 132 * @param ref reference to the picture
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133 */
134void avfilter_unref_pic(AVFilterPicRef *ref);
135
13ff8fd0 136/**
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137 * A list of supported formats for one end of a filter link. This is used
138 * during the format negotiation process to try to pick the best format to
139 * use to minimize the number of necessary conversions. Each filter gives a
140 * list of the formats supported by each input and output pad. The list
141 * given for each pad need not be distinct - they may be references to the
142 * same list of formats, as is often the case when a filter supports multiple
42f72a3a 143 * formats, but will always output the same format as it is given in input.
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144 *
145 * In this way, a list of possible input formats and a list of possible
146 * output formats are associated with each link. When a set of formats is
147 * negotiated over a link, the input and output lists are merged to form a
148 * new list containing only the common elements of each list. In the case
149 * that there were no common elements, a format conversion is necessary.
150 * Otherwise, the lists are merged, and all other links which reference
151 * either of the format lists involved in the merge are also affected.
152 *
153 * For example, consider the filter chain:
154 * filter (a) --> (b) filter (b) --> (c) filter
155 *
156 * where the letters in parenthesis indicate a list of formats supported on
157 * the input or output of the link. Suppose the lists are as follows:
158 * (a) = {A, B}
159 * (b) = {A, B, C}
160 * (c) = {B, C}
161 *
162 * First, the first link's lists are merged, yielding:
163 * filter (a) --> (a) filter (a) --> (c) filter
164 *
165 * Notice that format list (b) now refers to the same list as filter list (a).
166 * Next, the lists for the second link are merged, yielding:
167 * filter (a) --> (a) filter (a) --> (a) filter
168 *
169 * where (a) = {B}.
170 *
171 * Unfortunately, when the format lists at the two ends of a link are merged,
172 * we must ensure that all links which reference either pre-merge format list
173 * get updated as well. Therefore, we have the format list structure store a
174 * pointer to each of the pointers to itself.
175 */
176typedef struct AVFilterFormats AVFilterFormats;
177struct AVFilterFormats
178{
179 unsigned format_count; ///< number of formats
930aa451 180 enum PixelFormat *formats; ///< list of pixel formats
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181
182 unsigned refcount; ///< number of references to this list
183 AVFilterFormats ***refs; ///< references to this list
184};
185
186/**
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187 * Creates a list of supported formats. This is intended for use in
188 * AVFilter->query_formats().
189 * @param pix_fmt list of pixel formats, terminated by PIX_FMT_NONE
190 * @return the format list, with no existing references
191 */
9abba21a 192AVFilterFormats *avfilter_make_format_list(const enum PixelFormat *pix_fmts);
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193
194/**
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195 * Adds pix_fmt to the list of pixel formats contained in *avff.
196 * If *avff is NULL the function allocates the filter formats struct
197 * and puts its pointer in *avff.
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198 *
199 * @return a non negative value in case of success, or a negative
200 * value corresponding to an AVERROR code in case of error
201 */
c1d662fd 202int avfilter_add_colorspace(AVFilterFormats **avff, enum PixelFormat pix_fmt);
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203
204/**
853961a9 205 * Returns a list of all colorspaces supported by FFmpeg.
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206 */
207AVFilterFormats *avfilter_all_colorspaces(void);
208
209/**
33a0facf 210 * Returns a format list which contains the intersection of the formats of
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211 * a and b. Also, all the references of a, all the references of b, and
212 * a and b themselves will be deallocated.
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213 *
214 * If a and b do not share any common formats, neither is modified, and NULL
215 * is returned.
216 */
217AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
218
09b63a42 219/**
a27c8d5f 220 * Adds *ref as a new reference to formats.
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221 * That is the pointers will point like in the ascii art below:
222 * ________
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223 * |formats |<--------.
224 * | ____ | ____|___________________
225 * | |refs| | | __|_
226 * | |* * | | | | | | AVFilterLink
09b63a42 227 * | |* *--------->|*ref|
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228 * | |____| | | |____|
229 * |________| |________________________
09b63a42 230 */
a27c8d5f 231void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
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232
233/**
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234 * If *ref is non-NULL, removes *ref as a reference to the format list
235 * it currently points to, deallocates that list if this was the last
236 * reference, and sets *ref to NULL.
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237 *
238 * Before After
239 * ________ ________ NULL
240 * |formats |<--------. |formats | ^
241 * | ____ | ____|________________ | ____ | ____|________________
242 * | |refs| | | __|_ | |refs| | | __|_
243 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
244 * | |* *--------->|*ref| | |* | | | |*ref|
245 * | |____| | | |____| | |____| | | |____|
246 * |________| |_____________________ |________| |_____________________
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247 */
248void avfilter_formats_unref(AVFilterFormats **ref);
249
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250/**
251 *
252 * Before After
253 * ________ ________
a27c8d5f 254 * |formats |<---------. |formats |<---------.
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255 * | ____ | ___|___ | ____ | ___|___
256 * | |refs| | | | | | |refs| | | | | NULL
257 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
258 * | |* * | | |_______| | |* * | | |_______| ___|___
259 * | |____| | | |____| | | | |
260 * |________| |________| |*oldref|
261 * |_______|
262 */
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263void avfilter_formats_changeref(AVFilterFormats **oldref,
264 AVFilterFormats **newref);
265
35f3fdf4 266/**
664f6595 267 * A filter pad used for either input or output.
13ff8fd0 268 */
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269struct AVFilterPad
270{
271 /**
38efe768
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272 * Pad name. The name is unique among inputs and among outputs, but an
273 * input may have the same name as an output. This may be NULL if this
13ff8fd0 274 * pad has no need to ever be referenced by name.
a5cbb2f4 275 */
2844dd39 276 const char *name;
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277
278 /**
38efe768 279 * AVFilterPad type. Only video supported now, hopefully someone will
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280 * add audio in the future.
281 */
daafdb6e 282 enum CodecType type;
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283
284 /**
38efe768 285 * Minimum required permissions on incoming buffers. Any buffer with
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286 * insufficient permissions will be automatically copied by the filter
287 * system to a new buffer which provides the needed access permissions.
288 *
289 * Input pads only.
290 */
291 int min_perms;
292
293 /**
38efe768 294 * Permissions which are not accepted on incoming buffers. Any buffer
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295 * which has any of these permissions set will be automatically copied
296 * by the filter system to a new buffer which does not have those
38efe768 297 * permissions. This can be used to easily disallow buffers with
9ce95f27 298 * AV_PERM_REUSE.
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299 *
300 * Input pads only.
301 */
302 int rej_perms;
303
304 /**
38efe768 305 * Callback called before passing the first slice of a new frame. If
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306 * NULL, the filter layer will default to storing a reference to the
307 * picture inside the link structure.
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308 *
309 * Input video pads only.
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310 */
311 void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
312
313 /**
38efe768 314 * Callback function to get a buffer. If NULL, the filter system will
da23d424 315 * use avfilter_default_get_video_buffer().
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316 *
317 * Input video pads only.
a5cbb2f4 318 */
0eb4ff9e 319 AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
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320
321 /**
38efe768 322 * Callback called after the slices of a frame are completely sent. If
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323 * NULL, the filter layer will default to releasing the reference stored
324 * in the link structure during start_frame().
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325 *
326 * Input video pads only.
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327 */
328 void (*end_frame)(AVFilterLink *link);
329
330 /**
38efe768 331 * Slice drawing callback. This is where a filter receives video data
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332 * and should do its processing.
333 *
334 * Input video pads only.
a5cbb2f4 335 */
a13a5437 336 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
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337
338 /**
38efe768 339 * Frame poll callback. This returns the number of immediately available
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340 * frames. It should return a positive value if the next request_frame()
341 * is guaranteed to return one frame (with no delay).
342 *
343 * Defaults to just calling the source poll_frame() method.
344 *
345 * Output video pads only.
346 */
347 int (*poll_frame)(AVFilterLink *link);
348
349 /**
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350 * Frame request callback. A call to this should result in at least one
351 * frame being output over the given link. This should return zero on
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352 * success, and another value on error.
353 *
354 * Output video pads only.
a5cbb2f4 355 */
63f64e6f 356 int (*request_frame)(AVFilterLink *link);
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357
358 /**
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359 * Link configuration callback.
360 *
361 * For output pads, this should set the link properties such as
38efe768 362 * width/height. This should NOT set the format property - that is
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363 * negotiated between filters by the filter system using the
364 * query_formats() callback before this function is called.
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365 *
366 * For input pads, this should check the properties of the link, and update
367 * the filter's internal state as necessary.
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368 *
369 * For both input and output filters, this should return zero on success,
370 * and another value on error.
a5cbb2f4 371 */
d3e57c15 372 int (*config_props)(AVFilterLink *link);
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373};
374
2b187df9 375/** default handler for start_frame() for video inputs */
a5cbb2f4 376void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
b9609848 377/** default handler for draw_slice() for video inputs */
a13a5437 378void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
2b187df9 379/** default handler for end_frame() for video inputs */
a5cbb2f4 380void avfilter_default_end_frame(AVFilterLink *link);
2b187df9 381/** default handler for config_props() for video outputs */
901e6b39 382int avfilter_default_config_output_link(AVFilterLink *link);
2b187df9 383/** default handler for config_props() for video inputs */
85322466 384int avfilter_default_config_input_link (AVFilterLink *link);
2b187df9 385/** default handler for get_video_buffer() for video inputs */
901e6b39 386AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
0eb4ff9e 387 int perms, int w, int h);
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388/**
389 * A helper for query_formats() which sets all links to the same list of
390 * formats. If there are no links hooked to this filter, the list of formats is
391 * freed.
392 */
393void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
394/** Default handler for query_formats() */
395int avfilter_default_query_formats(AVFilterContext *ctx);
a5cbb2f4 396
13ff8fd0 397/**
38efe768 398 * Filter definition. This defines the pads a filter contains, and all the
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399 * callback functions used to interact with the filter.
400 */
243110f9 401typedef struct AVFilter
a5cbb2f4 402{
2844dd39 403 const char *name; ///< filter name
a5cbb2f4 404
13ff8fd0 405 int priv_size; ///< size of private data to allocate for the filter
a5cbb2f4 406
4d96a914 407 /**
38efe768
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408 * Filter initialization function. Args contains the user-supplied
409 * parameters. FIXME: maybe an AVOption-based system would be better?
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410 * opaque is data provided by the code requesting creation of the filter,
411 * and is used to pass data to the filter.
4d96a914 412 */
95bcf498 413 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
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414
415 /**
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416 * Filter uninitialization function. Should deallocate any memory held
417 * by the filter, release any picture references, etc. This does not need
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418 * to deallocate the AVFilterContext->priv memory itself.
419 */
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420 void (*uninit)(AVFilterContext *ctx);
421
35f3fdf4 422 /**
c4d2e41c 423 * Queries formats supported by the filter and its pads, and sets the
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424 * in_formats for links connected to its output pads, and out_formats
425 * for links connected to its input pads.
426 *
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427 * @return zero on success, a negative value corresponding to an
428 * AVERROR code otherwise
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429 */
430 int (*query_formats)(AVFilterContext *);
431
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432 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
433 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
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434
435 /**
436 * A description for the filter. You should use the
437 * NULL_IF_CONFIG_SMALL() macro to define it.
438 */
439 const char *description;
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440} AVFilter;
441
13ff8fd0 442/** An instance of a filter */
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443struct AVFilterContext
444{
d42a814e 445 const AVClass *av_class; ///< needed for av_log()
a5cbb2f4 446
664f6595 447 AVFilter *filter; ///< the AVFilter of which this is an instance
a5cbb2f4 448
13ff8fd0 449 char *name; ///< name of this filter instance
dcea2482 450
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451 unsigned input_count; ///< number of input pads
452 AVFilterPad *input_pads; ///< array of input pads
453 AVFilterLink **inputs; ///< array of pointers to input links
25f8e601 454
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455 unsigned output_count; ///< number of output pads
456 AVFilterPad *output_pads; ///< array of output pads
457 AVFilterLink **outputs; ///< array of pointers to output links
a5cbb2f4 458
13ff8fd0 459 void *priv; ///< private data for use by the filter
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460};
461
13ff8fd0 462/**
38efe768 463 * A link between two filters. This contains pointers to the source and
f4433de9 464 * destination filters between which this link exists, and the indexes of
38efe768 465 * the pads involved. In addition, this link also contains the parameters
13ff8fd0 466 * which have been negotiated and agreed upon between the filter, such as
2b187df9 467 * image dimensions, format, etc.
13ff8fd0 468 */
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469struct AVFilterLink
470{
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471 AVFilterContext *src; ///< source filter
472 unsigned int srcpad; ///< index of the output pad on the source filter
a5cbb2f4 473
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474 AVFilterContext *dst; ///< dest filter
475 unsigned int dstpad; ///< index of the input pad on the dest filter
a5cbb2f4 476
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477 /** stage of the initialization of the link properties (dimensions, etc) */
478 enum {
479 AVLINK_UNINIT = 0, ///< not started
480 AVLINK_STARTINIT, ///< started, but incomplete
481 AVLINK_INIT ///< complete
482 } init_state;
483
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484 int w; ///< agreed upon image width
485 int h; ///< agreed upon image height
486 enum PixelFormat format; ///< agreed upon image colorspace
a5cbb2f4 487
60bf6ce3 488 /**
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489 * Lists of formats supported by the input and output filters respectively.
490 * These lists are used for negotiating the format to actually be used,
491 * which will be loaded into the format member, above, when chosen.
492 */
493 AVFilterFormats *in_formats;
494 AVFilterFormats *out_formats;
495
496 /**
60bf6ce3 497 * The picture reference currently being sent across the link by the source
38efe768 498 * filter. This is used internally by the filter system to allow
664f6595 499 * automatic copying of pictures which do not have sufficient permissions
38efe768 500 * for the destination. This should not be accessed directly by the
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501 * filters.
502 */
503 AVFilterPicRef *srcpic;
504
a5cbb2f4 505 AVFilterPicRef *cur_pic;
462f57db 506 AVFilterPicRef *outpic;
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507};
508
13ff8fd0 509/**
c5c6f626 510 * Links two filters together.
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511 * @param src the source filter
512 * @param srcpad index of the output pad on the source filter
513 * @param dst the destination filter
514 * @param dstpad index of the input pad on the destination filter
515 * @return zero on success
13ff8fd0 516 */
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517int avfilter_link(AVFilterContext *src, unsigned srcpad,
518 AVFilterContext *dst, unsigned dstpad);
519
13ff8fd0 520/**
c5c6f626 521 * Negotiates the colorspace, dimensions, etc of all inputs to a filter.
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522 * @param filter the filter to negotiate the properties for its inputs
523 * @return zero on successful negotiation
13ff8fd0 524 */
24c4eff6 525int avfilter_config_links(AVFilterContext *filter);
85322466 526
13ff8fd0 527/**
c5c6f626 528 * Requests a picture buffer with a specific set of permissions.
664f6595 529 * @param link the output link to the filter from which the picture will
13ff8fd0 530 * be requested
664f6595 531 * @param perms the required access permissions
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532 * @param w the minimum width of the buffer to allocate
533 * @param h the minimum height of the buffer to allocate
38efe768 534 * @return A reference to the picture. This must be unreferenced with
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535 * avfilter_unref_pic when you are finished with it.
536 */
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537AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
538 int w, int h);
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539
540/**
c5c6f626 541 * Requests an input frame from the filter at the other end of the link.
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542 * @param link the input link
543 * @return zero on success
13ff8fd0 544 */
0155b1a1 545int avfilter_request_frame(AVFilterLink *link);
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546
547/**
c5c6f626 548 * Polls a frame from the filter chain.
b04c740a 549 * @param link the input link
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550 * @return the number of immediately available frames, a negative
551 * number in case of error
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552 */
553int avfilter_poll_frame(AVFilterLink *link);
554
555/**
c5c6f626 556 * Notifies the next filter of the start of a frame.
664f6595 557 * @param link the output link the frame will be sent over
38efe768 558 * @param picref A reference to the frame about to be sent. The data for this
13ff8fd0 559 * frame need only be valid once draw_slice() is called for that
38efe768 560 * portion. The receiving filter will free this reference when
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561 * it no longer needs it.
562 */
a5cbb2f4 563void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
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564
565/**
c5c6f626 566 * Notifies the next filter that the current frame has finished.
664f6595 567 * @param link the output link the frame was sent over
13ff8fd0 568 */
a5cbb2f4 569void avfilter_end_frame(AVFilterLink *link);
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570
571/**
c5c6f626 572 * Sends a slice to the next filter.
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573 *
574 * Slices have to be provided in sequential order, either in
575 * top-bottom or bottom-top order. If slices are provided in
576 * non-sequential order the behavior of the function is undefined.
577 *
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578 * @param link the output link over which the frame is being sent
579 * @param y offset in pixels from the top of the image for this slice
580 * @param h height of this slice in pixels
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581 * @param slice_dir the assumed direction for sending slices,
582 * from the top slice to the bottom slice if the value is 1,
583 * from the bottom slice to the top slice if the value is -1,
584 * for other values the behavior of the function is undefined.
13ff8fd0 585 */
a13a5437 586void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
a5cbb2f4 587
2be414c8 588/** Initializes the filter system. Registers all builtin filters. */
11de6cac 589void avfilter_register_all(void);
e4152452 590
2be414c8 591/** Uninitializes the filter system. Unregisters all filters. */
a5cbb2f4 592void avfilter_uninit(void);
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593
594/**
c5c6f626 595 * Registers a filter. This is only needed if you plan to use
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596 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
597 * filter can still by instantiated with avfilter_open even if it is not
598 * registered.
664f6595 599 * @param filter the filter to register
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600 * @return 0 if the registration was succesfull, a negative value
601 * otherwise
13ff8fd0 602 */
86a60fa1 603int avfilter_register(AVFilter *filter);
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604
605/**
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606 * Gets a filter definition matching the given name.
607 * @param name the filter name to find
608 * @return the filter definition, if any matching one is registered.
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609 * NULL if none found.
610 */
2844dd39 611AVFilter *avfilter_get_by_name(const char *name);
a5cbb2f4 612
13ff8fd0 613/**
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614 * If filter is NULL, returns a pointer to the first registered filter pointer,
615 * if filter is non-NULL, returns the next pointer after filter.
616 * If the returned pointer points to NULL, the last registered filter
617 * was already reached.
618 */
619AVFilter **av_filter_next(AVFilter **filter);
620
621/**
c5c6f626 622 * Creates a filter instance.
664f6595 623 * @param filter the filter to create an instance of
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624 * @param inst_name Name to give to the new instance. Can be NULL for none.
625 * @return Pointer to the new instance on success. NULL on failure.
13ff8fd0 626 */
2844dd39 627AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
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628
629/**
c5c6f626 630 * Initializes a filter.
664f6595 631 * @param filter the filter to initialize
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632 * @param args A string of parameters to use when initializing the filter.
633 * The format and meaning of this string varies by filter.
38efe768 634 * @param opaque Any extra non-string data needed by the filter. The meaning
13ff8fd0 635 * of this parameter varies by filter.
664f6595 636 * @return zero on success
13ff8fd0 637 */
6e365c57 638int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
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639
640/**
c5c6f626 641 * Destroys a filter.
664f6595 642 * @param filter the filter to destroy
13ff8fd0 643 */
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644void avfilter_destroy(AVFilterContext *filter);
645
13ff8fd0 646/**
c5c6f626 647 * Inserts a filter in the middle of an existing link.
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648 * @param link the link into which the filter should be inserted
649 * @param filt the filter to be inserted
650 * @param in the input pad on the filter to connect
651 * @param out the output pad on the filter to connect
652 * @return zero on success
13ff8fd0 653 */
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654int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
655 unsigned in, unsigned out);
d3e57c15 656
a9c81431 657/**
c5c6f626 658 * Inserts a new pad.
38efe768 659 * @param idx Insertion point. Pad is inserted at the end if this point
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660 * is beyond the end of the list of pads.
661 * @param count Pointer to the number of pads in the list
662 * @param padidx_off Offset within an AVFilterLink structure to the element
663 * to increment when inserting a new pad causes link
664 * numbering to change
665 * @param pads Pointer to the pointer to the beginning of the list of pads
666 * @param links Pointer to the pointer to the beginning of the list of links
667 * @param newpad The new pad to add. A copy is made when adding.
668 */
669void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
670 AVFilterPad **pads, AVFilterLink ***links,
671 AVFilterPad *newpad);
672
c5c6f626 673/** Inserts a new input pad for the filter. */
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674static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
675 AVFilterPad *p)
676{
677 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
678 &f->input_pads, &f->inputs, p);
679}
680
c5c6f626 681/** Inserts a new output pad for the filter. */
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682static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
683 AVFilterPad *p)
684{
685 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
686 &f->output_pads, &f->outputs, p);
687}
688
98790382 689#endif /* AVFILTER_AVFILTER_H */