Make av_get_random_seed() non-blocking
[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
b6bc2051 28#define LIBAVFILTER_VERSION_MINOR 20
6951515c 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
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42/**
43 * Returns the LIBAVFILTER_VERSION_INT constant.
44 */
45unsigned avfilter_version(void);
46
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47/**
48 * Returns the libavfilter build-time configuration.
49 */
41600690 50const char *avfilter_configuration(void);
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51
52/**
53 * Returns the libavfilter license.
54 */
41600690 55const char *avfilter_license(void);
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56
57
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58typedef struct AVFilterContext AVFilterContext;
59typedef struct AVFilterLink AVFilterLink;
60typedef struct AVFilterPad AVFilterPad;
61
62/* TODO: look for other flags which may be useful in this structure (interlace
63 * flags, etc)
64 */
65/**
38efe768 66 * A reference-counted picture data type used by the filter system. Filters
a5cbb2f4 67 * should not store pointers to this structure directly, but instead use the
664f6595 68 * AVFilterPicRef structure below.
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69 */
70typedef struct AVFilterPic
71{
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72 uint8_t *data[4]; ///< picture data for each plane
73 int linesize[4]; ///< number of bytes per line
74 enum PixelFormat format; ///< colorspace
a5cbb2f4 75
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76 unsigned refcount; ///< number of references to this image
77
78 /** private data to be used by a custom free function */
a5cbb2f4 79 void *priv;
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80 /**
81 * A pointer to the function to deallocate this image if the default
38efe768 82 * function is not sufficient. This could, for example, add the memory
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83 * back into a memory pool to be reused later without the overhead of
84 * reallocating it from scratch.
85 */
a5cbb2f4 86 void (*free)(struct AVFilterPic *pic);
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87
88 int w, h; ///< width and height of the allocated buffer
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89} AVFilterPic;
90
91/**
38efe768 92 * A reference to an AVFilterPic. Since filters can manipulate the origin of
a5cbb2f4 93 * a picture to, for example, crop image without any memcpy, the picture origin
38efe768 94 * and dimensions are per-reference properties. Linesize is also useful for
bbf42679 95 * image flipping, frame to field filters, etc, and so is also per-reference.
a5cbb2f4 96 *
1a18860a 97 * TODO: add anything necessary for frame reordering
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98 */
99typedef struct AVFilterPicRef
100{
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101 AVFilterPic *pic; ///< the picture that this is a reference to
102 uint8_t *data[4]; ///< picture data for each plane
103 int linesize[4]; ///< number of bytes per line
104 int w; ///< image width
105 int h; ///< image height
a5cbb2f4 106
056f0431 107 int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
5bb5c1dc 108 int64_t pos; ///< byte position in stream, -1 if unknown
1a18860a 109
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110 AVRational pixel_aspect; ///< pixel aspect ratio
111
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112 int perms; ///< permissions
113#define AV_PERM_READ 0x01 ///< can read from the buffer
114#define AV_PERM_WRITE 0x02 ///< can write to the buffer
115#define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
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116#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
117#define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
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118
119 int interlaced; ///< is frame interlaced
120 int top_field_first;
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121} AVFilterPicRef;
122
123/**
c5c6f626 124 * Adds a new reference to a picture.
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125 * @param ref an existing reference to the picture
126 * @param pmask a bitmask containing the allowable permissions in the new
13ff8fd0 127 * reference
664f6595 128 * @return a new reference to the picture with the same properties as the
13ff8fd0 129 * old, excluding any permissions denied by pmask
a5cbb2f4 130 */
16415eaf 131AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
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132
133/**
c5c6f626 134 * Removes a reference to a picture. If this is the last reference to the
a5cbb2f4 135 * picture, the picture itself is also automatically freed.
664f6595 136 * @param ref reference to the picture
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137 */
138void avfilter_unref_pic(AVFilterPicRef *ref);
139
13ff8fd0 140/**
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141 * A list of supported formats for one end of a filter link. This is used
142 * during the format negotiation process to try to pick the best format to
143 * use to minimize the number of necessary conversions. Each filter gives a
144 * list of the formats supported by each input and output pad. The list
145 * given for each pad need not be distinct - they may be references to the
146 * same list of formats, as is often the case when a filter supports multiple
42f72a3a 147 * formats, but will always output the same format as it is given in input.
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148 *
149 * In this way, a list of possible input formats and a list of possible
150 * output formats are associated with each link. When a set of formats is
151 * negotiated over a link, the input and output lists are merged to form a
152 * new list containing only the common elements of each list. In the case
153 * that there were no common elements, a format conversion is necessary.
154 * Otherwise, the lists are merged, and all other links which reference
155 * either of the format lists involved in the merge are also affected.
156 *
157 * For example, consider the filter chain:
158 * filter (a) --> (b) filter (b) --> (c) filter
159 *
160 * where the letters in parenthesis indicate a list of formats supported on
161 * the input or output of the link. Suppose the lists are as follows:
162 * (a) = {A, B}
163 * (b) = {A, B, C}
164 * (c) = {B, C}
165 *
166 * First, the first link's lists are merged, yielding:
167 * filter (a) --> (a) filter (a) --> (c) filter
168 *
169 * Notice that format list (b) now refers to the same list as filter list (a).
170 * Next, the lists for the second link are merged, yielding:
171 * filter (a) --> (a) filter (a) --> (a) filter
172 *
173 * where (a) = {B}.
174 *
175 * Unfortunately, when the format lists at the two ends of a link are merged,
176 * we must ensure that all links which reference either pre-merge format list
177 * get updated as well. Therefore, we have the format list structure store a
178 * pointer to each of the pointers to itself.
179 */
180typedef struct AVFilterFormats AVFilterFormats;
181struct AVFilterFormats
182{
183 unsigned format_count; ///< number of formats
930aa451 184 enum PixelFormat *formats; ///< list of pixel formats
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185
186 unsigned refcount; ///< number of references to this list
187 AVFilterFormats ***refs; ///< references to this list
188};
189
190/**
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191 * Creates a list of supported formats. This is intended for use in
192 * AVFilter->query_formats().
193 * @param pix_fmt list of pixel formats, terminated by PIX_FMT_NONE
194 * @return the format list, with no existing references
195 */
9abba21a 196AVFilterFormats *avfilter_make_format_list(const enum PixelFormat *pix_fmts);
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197
198/**
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199 * Adds pix_fmt to the list of pixel formats contained in *avff.
200 * If *avff is NULL the function allocates the filter formats struct
201 * and puts its pointer in *avff.
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202 *
203 * @return a non negative value in case of success, or a negative
204 * value corresponding to an AVERROR code in case of error
205 */
c1d662fd 206int avfilter_add_colorspace(AVFilterFormats **avff, enum PixelFormat pix_fmt);
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207
208/**
853961a9 209 * Returns a list of all colorspaces supported by FFmpeg.
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210 */
211AVFilterFormats *avfilter_all_colorspaces(void);
212
213/**
33a0facf 214 * Returns a format list which contains the intersection of the formats of
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215 * a and b. Also, all the references of a, all the references of b, and
216 * a and b themselves will be deallocated.
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217 *
218 * If a and b do not share any common formats, neither is modified, and NULL
219 * is returned.
220 */
221AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
222
09b63a42 223/**
a27c8d5f 224 * Adds *ref as a new reference to formats.
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225 * That is the pointers will point like in the ascii art below:
226 * ________
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227 * |formats |<--------.
228 * | ____ | ____|___________________
229 * | |refs| | | __|_
230 * | |* * | | | | | | AVFilterLink
09b63a42 231 * | |* *--------->|*ref|
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232 * | |____| | | |____|
233 * |________| |________________________
09b63a42 234 */
a27c8d5f 235void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
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236
237/**
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238 * If *ref is non-NULL, removes *ref as a reference to the format list
239 * it currently points to, deallocates that list if this was the last
240 * reference, and sets *ref to NULL.
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241 *
242 * Before After
243 * ________ ________ NULL
244 * |formats |<--------. |formats | ^
245 * | ____ | ____|________________ | ____ | ____|________________
246 * | |refs| | | __|_ | |refs| | | __|_
247 * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
248 * | |* *--------->|*ref| | |* | | | |*ref|
249 * | |____| | | |____| | |____| | | |____|
250 * |________| |_____________________ |________| |_____________________
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251 */
252void avfilter_formats_unref(AVFilterFormats **ref);
253
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254/**
255 *
256 * Before After
257 * ________ ________
a27c8d5f 258 * |formats |<---------. |formats |<---------.
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259 * | ____ | ___|___ | ____ | ___|___
260 * | |refs| | | | | | |refs| | | | | NULL
261 * | |* *--------->|*oldref| | |* *--------->|*newref| ^
262 * | |* * | | |_______| | |* * | | |_______| ___|___
263 * | |____| | | |____| | | | |
264 * |________| |________| |*oldref|
265 * |_______|
266 */
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267void avfilter_formats_changeref(AVFilterFormats **oldref,
268 AVFilterFormats **newref);
269
35f3fdf4 270/**
664f6595 271 * A filter pad used for either input or output.
13ff8fd0 272 */
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273struct AVFilterPad
274{
275 /**
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276 * Pad name. The name is unique among inputs and among outputs, but an
277 * input may have the same name as an output. This may be NULL if this
13ff8fd0 278 * pad has no need to ever be referenced by name.
a5cbb2f4 279 */
2844dd39 280 const char *name;
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281
282 /**
38efe768 283 * AVFilterPad type. Only video supported now, hopefully someone will
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284 * add audio in the future.
285 */
72415b2a 286 enum AVMediaType type;
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287
288 /**
38efe768 289 * Minimum required permissions on incoming buffers. Any buffer with
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290 * insufficient permissions will be automatically copied by the filter
291 * system to a new buffer which provides the needed access permissions.
292 *
293 * Input pads only.
294 */
295 int min_perms;
296
297 /**
38efe768 298 * Permissions which are not accepted on incoming buffers. Any buffer
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299 * which has any of these permissions set will be automatically copied
300 * by the filter system to a new buffer which does not have those
38efe768 301 * permissions. This can be used to easily disallow buffers with
9ce95f27 302 * AV_PERM_REUSE.
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303 *
304 * Input pads only.
305 */
306 int rej_perms;
307
308 /**
38efe768 309 * Callback called before passing the first slice of a new frame. If
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310 * NULL, the filter layer will default to storing a reference to the
311 * picture inside the link structure.
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312 *
313 * Input video pads only.
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314 */
315 void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
316
317 /**
38efe768 318 * Callback function to get a buffer. If NULL, the filter system will
da23d424 319 * use avfilter_default_get_video_buffer().
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320 *
321 * Input video pads only.
a5cbb2f4 322 */
0eb4ff9e 323 AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
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324
325 /**
38efe768 326 * Callback called after the slices of a frame are completely sent. If
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327 * NULL, the filter layer will default to releasing the reference stored
328 * in the link structure during start_frame().
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329 *
330 * Input video pads only.
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331 */
332 void (*end_frame)(AVFilterLink *link);
333
334 /**
38efe768 335 * Slice drawing callback. This is where a filter receives video data
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336 * and should do its processing.
337 *
338 * Input video pads only.
a5cbb2f4 339 */
a13a5437 340 void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
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341
342 /**
38efe768 343 * Frame poll callback. This returns the number of immediately available
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344 * frames. It should return a positive value if the next request_frame()
345 * is guaranteed to return one frame (with no delay).
346 *
347 * Defaults to just calling the source poll_frame() method.
348 *
349 * Output video pads only.
350 */
351 int (*poll_frame)(AVFilterLink *link);
352
353 /**
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354 * Frame request callback. A call to this should result in at least one
355 * frame being output over the given link. This should return zero on
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356 * success, and another value on error.
357 *
358 * Output video pads only.
a5cbb2f4 359 */
63f64e6f 360 int (*request_frame)(AVFilterLink *link);
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361
362 /**
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363 * Link configuration callback.
364 *
365 * For output pads, this should set the link properties such as
38efe768 366 * width/height. This should NOT set the format property - that is
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367 * negotiated between filters by the filter system using the
368 * query_formats() callback before this function is called.
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369 *
370 * For input pads, this should check the properties of the link, and update
371 * the filter's internal state as necessary.
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372 *
373 * For both input and output filters, this should return zero on success,
374 * and another value on error.
a5cbb2f4 375 */
d3e57c15 376 int (*config_props)(AVFilterLink *link);
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377};
378
2b187df9 379/** default handler for start_frame() for video inputs */
a5cbb2f4 380void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
b9609848 381/** default handler for draw_slice() for video inputs */
a13a5437 382void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
2b187df9 383/** default handler for end_frame() for video inputs */
a5cbb2f4 384void avfilter_default_end_frame(AVFilterLink *link);
2b187df9 385/** default handler for config_props() for video outputs */
901e6b39 386int avfilter_default_config_output_link(AVFilterLink *link);
2b187df9 387/** default handler for config_props() for video inputs */
85322466 388int avfilter_default_config_input_link (AVFilterLink *link);
2b187df9 389/** default handler for get_video_buffer() for video inputs */
901e6b39 390AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
0eb4ff9e 391 int perms, int w, int h);
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392/**
393 * A helper for query_formats() which sets all links to the same list of
394 * formats. If there are no links hooked to this filter, the list of formats is
395 * freed.
396 */
397void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
398/** Default handler for query_formats() */
399int avfilter_default_query_formats(AVFilterContext *ctx);
a5cbb2f4 400
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401/** start_frame() handler for filters which simply pass video along */
402void avfilter_null_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
403
404/** draw_slice() handler for filters which simply pass video along */
405void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
406
407/** end_frame() handler for filters which simply pass video along */
408void avfilter_null_end_frame(AVFilterLink *link);
409
410/** get_video_buffer() handler for filters which simply pass video along */
411AVFilterPicRef *avfilter_null_get_video_buffer(AVFilterLink *link,
412 int perms, int w, int h);
413
13ff8fd0 414/**
38efe768 415 * Filter definition. This defines the pads a filter contains, and all the
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416 * callback functions used to interact with the filter.
417 */
243110f9 418typedef struct AVFilter
a5cbb2f4 419{
2844dd39 420 const char *name; ///< filter name
a5cbb2f4 421
13ff8fd0 422 int priv_size; ///< size of private data to allocate for the filter
a5cbb2f4 423
4d96a914 424 /**
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425 * Filter initialization function. Args contains the user-supplied
426 * parameters. FIXME: maybe an AVOption-based system would be better?
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427 * opaque is data provided by the code requesting creation of the filter,
428 * and is used to pass data to the filter.
4d96a914 429 */
95bcf498 430 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
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431
432 /**
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433 * Filter uninitialization function. Should deallocate any memory held
434 * by the filter, release any picture references, etc. This does not need
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435 * to deallocate the AVFilterContext->priv memory itself.
436 */
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437 void (*uninit)(AVFilterContext *ctx);
438
35f3fdf4 439 /**
c4d2e41c 440 * Queries formats supported by the filter and its pads, and sets the
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441 * in_formats for links connected to its output pads, and out_formats
442 * for links connected to its input pads.
443 *
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444 * @return zero on success, a negative value corresponding to an
445 * AVERROR code otherwise
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446 */
447 int (*query_formats)(AVFilterContext *);
448
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449 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
450 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
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451
452 /**
453 * A description for the filter. You should use the
454 * NULL_IF_CONFIG_SMALL() macro to define it.
455 */
456 const char *description;
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457} AVFilter;
458
13ff8fd0 459/** An instance of a filter */
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460struct AVFilterContext
461{
d42a814e 462 const AVClass *av_class; ///< needed for av_log()
a5cbb2f4 463
664f6595 464 AVFilter *filter; ///< the AVFilter of which this is an instance
a5cbb2f4 465
13ff8fd0 466 char *name; ///< name of this filter instance
dcea2482 467
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468 unsigned input_count; ///< number of input pads
469 AVFilterPad *input_pads; ///< array of input pads
470 AVFilterLink **inputs; ///< array of pointers to input links
25f8e601 471
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472 unsigned output_count; ///< number of output pads
473 AVFilterPad *output_pads; ///< array of output pads
474 AVFilterLink **outputs; ///< array of pointers to output links
a5cbb2f4 475
13ff8fd0 476 void *priv; ///< private data for use by the filter
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477};
478
13ff8fd0 479/**
38efe768 480 * A link between two filters. This contains pointers to the source and
f4433de9 481 * destination filters between which this link exists, and the indexes of
38efe768 482 * the pads involved. In addition, this link also contains the parameters
13ff8fd0 483 * which have been negotiated and agreed upon between the filter, such as
2b187df9 484 * image dimensions, format, etc.
13ff8fd0 485 */
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486struct AVFilterLink
487{
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488 AVFilterContext *src; ///< source filter
489 unsigned int srcpad; ///< index of the output pad on the source filter
a5cbb2f4 490
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491 AVFilterContext *dst; ///< dest filter
492 unsigned int dstpad; ///< index of the input pad on the dest filter
a5cbb2f4 493
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494 /** stage of the initialization of the link properties (dimensions, etc) */
495 enum {
496 AVLINK_UNINIT = 0, ///< not started
497 AVLINK_STARTINIT, ///< started, but incomplete
498 AVLINK_INIT ///< complete
499 } init_state;
500
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501 int w; ///< agreed upon image width
502 int h; ///< agreed upon image height
503 enum PixelFormat format; ///< agreed upon image colorspace
a5cbb2f4 504
60bf6ce3 505 /**
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506 * Lists of formats supported by the input and output filters respectively.
507 * These lists are used for negotiating the format to actually be used,
508 * which will be loaded into the format member, above, when chosen.
509 */
510 AVFilterFormats *in_formats;
511 AVFilterFormats *out_formats;
512
513 /**
60bf6ce3 514 * The picture reference currently being sent across the link by the source
38efe768 515 * filter. This is used internally by the filter system to allow
664f6595 516 * automatic copying of pictures which do not have sufficient permissions
38efe768 517 * for the destination. This should not be accessed directly by the
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518 * filters.
519 */
520 AVFilterPicRef *srcpic;
521
a5cbb2f4 522 AVFilterPicRef *cur_pic;
462f57db 523 AVFilterPicRef *outpic;
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524};
525
13ff8fd0 526/**
c5c6f626 527 * Links two filters together.
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528 * @param src the source filter
529 * @param srcpad index of the output pad on the source filter
530 * @param dst the destination filter
531 * @param dstpad index of the input pad on the destination filter
532 * @return zero on success
13ff8fd0 533 */
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534int avfilter_link(AVFilterContext *src, unsigned srcpad,
535 AVFilterContext *dst, unsigned dstpad);
536
13ff8fd0 537/**
c5c6f626 538 * Negotiates the colorspace, dimensions, etc of all inputs to a filter.
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539 * @param filter the filter to negotiate the properties for its inputs
540 * @return zero on successful negotiation
13ff8fd0 541 */
24c4eff6 542int avfilter_config_links(AVFilterContext *filter);
85322466 543
13ff8fd0 544/**
c5c6f626 545 * Requests a picture buffer with a specific set of permissions.
664f6595 546 * @param link the output link to the filter from which the picture will
13ff8fd0 547 * be requested
664f6595 548 * @param perms the required access permissions
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549 * @param w the minimum width of the buffer to allocate
550 * @param h the minimum height of the buffer to allocate
38efe768 551 * @return A reference to the picture. This must be unreferenced with
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552 * avfilter_unref_pic when you are finished with it.
553 */
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554AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
555 int w, int h);
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556
557/**
c5c6f626 558 * Requests an input frame from the filter at the other end of the link.
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559 * @param link the input link
560 * @return zero on success
13ff8fd0 561 */
0155b1a1 562int avfilter_request_frame(AVFilterLink *link);
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563
564/**
c5c6f626 565 * Polls a frame from the filter chain.
b04c740a 566 * @param link the input link
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567 * @return the number of immediately available frames, a negative
568 * number in case of error
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569 */
570int avfilter_poll_frame(AVFilterLink *link);
571
572/**
c5c6f626 573 * Notifies the next filter of the start of a frame.
664f6595 574 * @param link the output link the frame will be sent over
38efe768 575 * @param picref A reference to the frame about to be sent. The data for this
13ff8fd0 576 * frame need only be valid once draw_slice() is called for that
38efe768 577 * portion. The receiving filter will free this reference when
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578 * it no longer needs it.
579 */
a5cbb2f4 580void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
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581
582/**
c5c6f626 583 * Notifies the next filter that the current frame has finished.
664f6595 584 * @param link the output link the frame was sent over
13ff8fd0 585 */
a5cbb2f4 586void avfilter_end_frame(AVFilterLink *link);
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587
588/**
c5c6f626 589 * Sends a slice to the next filter.
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590 *
591 * Slices have to be provided in sequential order, either in
592 * top-bottom or bottom-top order. If slices are provided in
593 * non-sequential order the behavior of the function is undefined.
594 *
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595 * @param link the output link over which the frame is being sent
596 * @param y offset in pixels from the top of the image for this slice
597 * @param h height of this slice in pixels
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598 * @param slice_dir the assumed direction for sending slices,
599 * from the top slice to the bottom slice if the value is 1,
600 * from the bottom slice to the top slice if the value is -1,
601 * for other values the behavior of the function is undefined.
13ff8fd0 602 */
a13a5437 603void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
a5cbb2f4 604
2be414c8 605/** Initializes the filter system. Registers all builtin filters. */
11de6cac 606void avfilter_register_all(void);
e4152452 607
2be414c8 608/** Uninitializes the filter system. Unregisters all filters. */
a5cbb2f4 609void avfilter_uninit(void);
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610
611/**
c5c6f626 612 * Registers a filter. This is only needed if you plan to use
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613 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
614 * filter can still by instantiated with avfilter_open even if it is not
615 * registered.
664f6595 616 * @param filter the filter to register
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617 * @return 0 if the registration was succesfull, a negative value
618 * otherwise
13ff8fd0 619 */
86a60fa1 620int avfilter_register(AVFilter *filter);
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621
622/**
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623 * Gets a filter definition matching the given name.
624 * @param name the filter name to find
625 * @return the filter definition, if any matching one is registered.
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626 * NULL if none found.
627 */
2844dd39 628AVFilter *avfilter_get_by_name(const char *name);
a5cbb2f4 629
13ff8fd0 630/**
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631 * If filter is NULL, returns a pointer to the first registered filter pointer,
632 * if filter is non-NULL, returns the next pointer after filter.
633 * If the returned pointer points to NULL, the last registered filter
634 * was already reached.
635 */
636AVFilter **av_filter_next(AVFilter **filter);
637
638/**
c5c6f626 639 * Creates a filter instance.
664f6595 640 * @param filter the filter to create an instance of
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641 * @param inst_name Name to give to the new instance. Can be NULL for none.
642 * @return Pointer to the new instance on success. NULL on failure.
13ff8fd0 643 */
2844dd39 644AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
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645
646/**
c5c6f626 647 * Initializes a filter.
664f6595 648 * @param filter the filter to initialize
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649 * @param args A string of parameters to use when initializing the filter.
650 * The format and meaning of this string varies by filter.
38efe768 651 * @param opaque Any extra non-string data needed by the filter. The meaning
13ff8fd0 652 * of this parameter varies by filter.
664f6595 653 * @return zero on success
13ff8fd0 654 */
6e365c57 655int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
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656
657/**
c5c6f626 658 * Destroys a filter.
664f6595 659 * @param filter the filter to destroy
13ff8fd0 660 */
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661void avfilter_destroy(AVFilterContext *filter);
662
13ff8fd0 663/**
c5c6f626 664 * Inserts a filter in the middle of an existing link.
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665 * @param link the link into which the filter should be inserted
666 * @param filt the filter to be inserted
667 * @param in the input pad on the filter to connect
668 * @param out the output pad on the filter to connect
669 * @return zero on success
13ff8fd0 670 */
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671int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
672 unsigned in, unsigned out);
d3e57c15 673
a9c81431 674/**
c5c6f626 675 * Inserts a new pad.
38efe768 676 * @param idx Insertion point. Pad is inserted at the end if this point
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677 * is beyond the end of the list of pads.
678 * @param count Pointer to the number of pads in the list
679 * @param padidx_off Offset within an AVFilterLink structure to the element
680 * to increment when inserting a new pad causes link
681 * numbering to change
682 * @param pads Pointer to the pointer to the beginning of the list of pads
683 * @param links Pointer to the pointer to the beginning of the list of links
684 * @param newpad The new pad to add. A copy is made when adding.
685 */
686void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
687 AVFilterPad **pads, AVFilterLink ***links,
688 AVFilterPad *newpad);
689
c5c6f626 690/** Inserts a new input pad for the filter. */
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691static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
692 AVFilterPad *p)
693{
694 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
695 &f->input_pads, &f->inputs, p);
696}
697
c5c6f626 698/** Inserts a new output pad for the filter. */
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699static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
700 AVFilterPad *p)
701{
702 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
703 &f->output_pads, &f->outputs, p);
704}
705
98790382 706#endif /* AVFILTER_AVFILTER_H */