h264_metadata: Add option to delete filler data
[libav.git] / libavfilter / avfilter.h
CommitLineData
a5cbb2f4 1/*
664f6595 2 * filter layer
3fa77bde 3 * Copyright (c) 2007 Bobby Bingham
a5cbb2f4 4 *
2912e87a 5 * This file is part of Libav.
a5cbb2f4 6 *
2912e87a 7 * Libav is free software; you can redistribute it and/or
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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 *
2912e87a 12 * Libav is distributed in the hope that it will be useful,
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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
2912e87a 18 * License along with Libav; if not, write to the Free Software
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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/**
26 * @file
27 * @ingroup lavfi
28 * Main libavfilter public API header
29 */
30
31/**
32 * @defgroup lavfi Libavfilter - graph-based frame editing library
33 * @{
34 */
35
bf4b0ed1 36#include "libavutil/attributes.h"
1f20782c 37#include "libavutil/avutil.h"
b3dd30db 38#include "libavutil/buffer.h"
7e350379 39#include "libavutil/frame.h"
abc78a5a 40#include "libavutil/log.h"
737eb597 41#include "libavutil/samplefmt.h"
d49ea4af 42#include "libavutil/pixfmt.h"
e91709ca 43#include "libavutil/rational.h"
1f20782c 44
a9c81431 45#include <stddef.h>
a5cbb2f4 46
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47#include "libavfilter/version.h"
48
540f1c7b 49/**
49bd8e4b 50 * Return the LIBAVFILTER_VERSION_INT constant.
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51 */
52unsigned avfilter_version(void);
53
c1736936 54/**
49bd8e4b 55 * Return the libavfilter build-time configuration.
c1736936 56 */
41600690 57const char *avfilter_configuration(void);
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58
59/**
49bd8e4b 60 * Return the libavfilter license.
c1736936 61 */
41600690 62const char *avfilter_license(void);
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63
64
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65typedef struct AVFilterContext AVFilterContext;
66typedef struct AVFilterLink AVFilterLink;
67typedef struct AVFilterPad AVFilterPad;
b74a1da4 68typedef struct AVFilterFormats AVFilterFormats;
a5cbb2f4 69
84b9fbe0 70/**
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71 * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
72 * AVFilter.inputs/outputs).
73 */
74int avfilter_pad_count(const AVFilterPad *pads);
75
76/**
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77 * Get the name of an AVFilterPad.
78 *
79 * @param pads an array of AVFilterPads
80 * @param pad_idx index of the pad in the array it; is the caller's
81 * responsibility to ensure the index is valid
82 *
83 * @return name of the pad_idx'th pad in pads
84 */
4a37d4b3 85const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
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86
87/**
88 * Get the type of an AVFilterPad.
89 *
90 * @param pads an array of AVFilterPads
91 * @param pad_idx index of the pad in the array; it is the caller's
92 * responsibility to ensure the index is valid
93 *
94 * @return type of the pad_idx'th pad in pads
95 */
4a37d4b3 96enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
84b9fbe0 97
13ff8fd0 98/**
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99 * The number of the filter inputs is not determined just by AVFilter.inputs.
100 * The filter might add additional inputs during initialization depending on the
101 * options supplied to it.
102 */
103#define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
104/**
105 * The number of the filter outputs is not determined just by AVFilter.outputs.
106 * The filter might add additional outputs during initialization depending on
107 * the options supplied to it.
108 */
109#define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
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110/**
111 * The filter supports multithreading by splitting frames into multiple parts
112 * and processing them concurrently.
113 */
114#define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
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115
116/**
38efe768 117 * Filter definition. This defines the pads a filter contains, and all the
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118 * callback functions used to interact with the filter.
119 */
f607cc18 120typedef struct AVFilter {
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121 /**
122 * Filter name. Must be non-NULL and unique among filters.
123 */
124 const char *name;
a5cbb2f4 125
96180805 126 /**
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127 * A description of the filter. May be NULL.
128 *
129 * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
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130 */
131 const char *description;
132
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133 /**
134 * List of inputs, terminated by a zeroed element.
135 *
136 * NULL if there are no (static) inputs. Instances of filters with
137 * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in
138 * this list.
139 */
140 const AVFilterPad *inputs;
141 /**
142 * List of outputs, terminated by a zeroed element.
143 *
144 * NULL if there are no (static) outputs. Instances of filters with
145 * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in
146 * this list.
147 */
148 const AVFilterPad *outputs;
96180805 149
b439c992 150 /**
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151 * A class for the private data, used to declare filter private AVOptions.
152 * This field is NULL for filters that do not declare any options.
153 *
154 * If this field is non-NULL, the first member of the filter private data
155 * must be a pointer to AVClass, which will be set by libavfilter generic
156 * code to this class.
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157 */
158 const AVClass *priv_class;
159
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160 /**
161 * A combination of AVFILTER_FLAG_*
162 */
163 int flags;
164
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165 /*****************************************************************
166 * All fields below this line are not part of the public API. They
167 * may not be used outside of libavfilter and can be changed and
168 * removed at will.
169 * New public fields should be added right above.
170 *****************************************************************
171 */
a5cbb2f4 172
4d96a914 173 /**
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174 * Filter initialization function.
175 *
176 * This callback will be called only once during the filter lifetime, after
177 * all the options have been set, but before links between filters are
178 * established and format negotiation is done.
179 *
180 * Basic filter initialization should be done here. Filters with dynamic
181 * inputs and/or outputs should create those inputs/outputs here based on
182 * provided options. No more changes to this filter's inputs/outputs can be
183 * done after this callback.
184 *
185 * This callback must not assume that the filter links exist or frame
186 * parameters are known.
187 *
188 * @ref AVFilter.uninit "uninit" is guaranteed to be called even if
189 * initialization fails, so this callback does not have to clean up on
190 * failure.
191 *
192 * @return 0 on success, a negative AVERROR on failure
4d96a914 193 */
c43a7eca 194 int (*init)(AVFilterContext *ctx);
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195
196 /**
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197 * Should be set instead of @ref AVFilter.init "init" by the filters that
198 * want to pass a dictionary of AVOptions to nested contexts that are
199 * allocated during init.
200 *
201 * On return, the options dict should be freed and replaced with one that
202 * contains all the options which could not be processed by this filter (or
203 * with NULL if all the options were processed).
204 *
205 * Otherwise the semantics is the same as for @ref AVFilter.init "init".
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206 */
207 int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
208
209 /**
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210 * Filter uninitialization function.
211 *
212 * Called only once right before the filter is freed. Should deallocate any
213 * memory held by the filter, release any buffer references, etc. It does
214 * not need to deallocate the AVFilterContext.priv memory itself.
215 *
216 * This callback may be called even if @ref AVFilter.init "init" was not
217 * called or failed, so it must be prepared to handle such a situation.
13ff8fd0 218 */
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219 void (*uninit)(AVFilterContext *ctx);
220
35f3fdf4 221 /**
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222 * Query formats supported by the filter on its inputs and outputs.
223 *
224 * This callback is called after the filter is initialized (so the inputs
225 * and outputs are fixed), shortly before the format negotiation. This
226 * callback may be called more than once.
227 *
228 * This callback must set AVFilterLink.out_formats on every input link and
229 * AVFilterLink.in_formats on every output link to a list of pixel/sample
230 * formats that the filter supports on that link. For audio links, this
231 * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" /
232 * @ref AVFilterLink.out_samplerates "out_samplerates" and
233 * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" /
234 * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously.
235 *
236 * This callback may be NULL for filters with one input, in which case
237 * libavfilter assumes that it supports all input formats and preserves
238 * them on output.
35f3fdf4 239 *
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240 * @return zero on success, a negative value corresponding to an
241 * AVERROR code otherwise
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242 */
243 int (*query_formats)(AVFilterContext *);
244
96180805 245 int priv_size; ///< size of private data to allocate for the filter
fa2a34cd 246
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247 int flags_internal; ///< Additional flags for avfilter internal use only.
248
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249 /**
250 * Used by the filter registration system. Must not be touched by any other
251 * code.
252 */
fa2a34cd 253 struct AVFilter *next;
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254} AVFilter;
255
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256/**
257 * Process multiple parts of the frame concurrently.
258 */
259#define AVFILTER_THREAD_SLICE (1 << 0)
260
261typedef struct AVFilterInternal AVFilterInternal;
262
13ff8fd0 263/** An instance of a filter */
f607cc18 264struct AVFilterContext {
d42a814e 265 const AVClass *av_class; ///< needed for av_log()
a5cbb2f4 266
91d2efa7 267 const AVFilter *filter; ///< the AVFilter of which this is an instance
a5cbb2f4 268
13ff8fd0 269 char *name; ///< name of this filter instance
dcea2482 270
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271 AVFilterPad *input_pads; ///< array of input pads
272 AVFilterLink **inputs; ///< array of pointers to input links
f892013a 273 unsigned nb_inputs; ///< number of input pads
25f8e601 274
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275 AVFilterPad *output_pads; ///< array of output pads
276 AVFilterLink **outputs; ///< array of pointers to output links
f892013a 277 unsigned nb_outputs; ///< number of output pads
a5cbb2f4 278
13ff8fd0 279 void *priv; ///< private data for use by the filter
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280
281 struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
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282
283 /**
284 * Type of multithreading being allowed/used. A combination of
285 * AVFILTER_THREAD_* flags.
286 *
287 * May be set by the caller before initializing the filter to forbid some
288 * or all kinds of multithreading for this filter. The default is allowing
289 * everything.
290 *
291 * When the filter is initialized, this field is combined using bit AND with
292 * AVFilterGraph.thread_type to get the final mask used for determining
293 * allowed threading types. I.e. a threading type needs to be set in both
294 * to be allowed.
295 *
296 * After the filter is initialzed, libavfilter sets this field to the
297 * threading type that is actually used (0 for no multithreading).
298 */
299 int thread_type;
300
301 /**
302 * An opaque struct for libavfilter internal use.
303 */
304 AVFilterInternal *internal;
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305
306 /**
307 * For filters which will create hardware frames, sets the device the
308 * filter should create them in. All other filters will ignore this field:
309 * in particular, a filter which consumes or processes hardware frames will
310 * instead use the hw_frames_ctx field in AVFilterLink to carry the
311 * hardware context information.
312 */
313 AVBufferRef *hw_device_ctx;
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314
315 /**
316 * Sets the number of extra hardware frames which the filter will
317 * allocate on its output links for use in following filters or by
318 * the caller.
319 *
320 * Some hardware filters require all frames that they will use for
321 * output to be defined in advance before filtering starts. For such
322 * filters, any hardware frame pools used for output must therefore be
323 * of fixed size. The extra frames set here are on top of any number
324 * that the filter needs internally in order to operate normally.
325 *
326 * This field must be set before the graph containing this filter is
327 * configured.
328 */
329 int extra_hw_frames;
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330};
331
13ff8fd0 332/**
38efe768 333 * A link between two filters. This contains pointers to the source and
f4433de9 334 * destination filters between which this link exists, and the indexes of
38efe768 335 * the pads involved. In addition, this link also contains the parameters
13ff8fd0 336 * which have been negotiated and agreed upon between the filter, such as
2b187df9 337 * image dimensions, format, etc.
13ff8fd0 338 */
f607cc18 339struct AVFilterLink {
13ff8fd0 340 AVFilterContext *src; ///< source filter
acc0490f 341 AVFilterPad *srcpad; ///< output pad on the source filter
a5cbb2f4 342
13ff8fd0 343 AVFilterContext *dst; ///< dest filter
acc0490f 344 AVFilterPad *dstpad; ///< input pad on the dest filter
a5cbb2f4 345
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346 enum AVMediaType type; ///< filter media type
347
910b5b82 348 /* These parameters apply only to video */
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349 int w; ///< agreed upon image width
350 int h; ///< agreed upon image height
910b5b82 351 AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
ad2c9501 352 /* These two parameters apply only to audio */
a903f8f0 353 uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
f20ab492 354 int sample_rate; ///< samples per second
ad2c9501 355
bdab614b 356 int format; ///< agreed upon media format
a5cbb2f4 357
60bf6ce3 358 /**
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359 * Define the time base used by the PTS of the frames/samples
360 * which will pass through this link.
361 * During the configuration stage, each filter is supposed to
362 * change only the output timebase, while the timebase of the
363 * input link is assumed to be an unchangeable property.
364 */
365 AVRational time_base;
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366
367 /*****************************************************************
368 * All fields below this line are not part of the public API. They
369 * may not be used outside of libavfilter and can be changed and
370 * removed at will.
371 * New public fields should be added right above.
372 *****************************************************************
373 */
374 /**
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375 * Lists of formats supported by the input and output filters respectively.
376 * These lists are used for negotiating the format to actually be used,
377 * which will be loaded into the format member, above, when chosen.
378 */
379 AVFilterFormats *in_formats;
380 AVFilterFormats *out_formats;
381
382 /**
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383 * Lists of channel layouts and sample rates used for automatic
384 * negotiation.
385 */
386 AVFilterFormats *in_samplerates;
387 AVFilterFormats *out_samplerates;
388 struct AVFilterChannelLayouts *in_channel_layouts;
389 struct AVFilterChannelLayouts *out_channel_layouts;
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390
391 /**
392 * Audio only, the destination filter sets this to a non-zero value to
393 * request that buffers with the given number of samples should be sent to
394 * it. AVFilterPad.needs_fifo must also be set on the corresponding input
395 * pad.
396 * Last buffer before EOF will be padded with silence.
397 */
398 int request_samples;
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399
400 /** stage of the initialization of the link properties (dimensions, etc) */
401 enum {
402 AVLINK_UNINIT = 0, ///< not started
403 AVLINK_STARTINIT, ///< started, but incomplete
404 AVLINK_INIT ///< complete
405 } init_state;
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406
407 /**
408 * Frame rate of the stream on the link, or 1/0 if unknown or variable;
409 * if left to 0/0, will be automatically copied from the first input
410 * of the source filter if it exists.
411 *
412 * Sources should set it to the real constant frame rate.
413 * If the source frame rate is unknown or variable, set this to 1/0.
414 * Filters should update it if necessary depending on their function.
415 * Sinks can use it to set a default output frame rate.
416 */
417 AVRational frame_rate;
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418
419 /**
420 * For hwaccel pixel formats, this should be a reference to the
421 * AVHWFramesContext describing the frames.
422 */
423 AVBufferRef *hw_frames_ctx;
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424};
425
13ff8fd0 426/**
49bd8e4b 427 * Link two filters together.
3fa3e4f4 428 *
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429 * @param src the source filter
430 * @param srcpad index of the output pad on the source filter
431 * @param dst the destination filter
432 * @param dstpad index of the input pad on the destination filter
433 * @return zero on success
13ff8fd0 434 */
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435int avfilter_link(AVFilterContext *src, unsigned srcpad,
436 AVFilterContext *dst, unsigned dstpad);
437
13ff8fd0 438/**
bdab614b 439 * Negotiate the media format, dimensions, etc of all inputs to a filter.
3fa3e4f4 440 *
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441 * @param filter the filter to negotiate the properties for its inputs
442 * @return zero on successful negotiation
13ff8fd0 443 */
24c4eff6 444int avfilter_config_links(AVFilterContext *filter);
85322466 445
49bd8e4b 446/** Initialize the filter system. Register all builtin filters. */
11de6cac 447void avfilter_register_all(void);
e4152452 448
13ff8fd0 449/**
49bd8e4b 450 * Register a filter. This is only needed if you plan to use
fc815c56 451 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
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452 * filter can still by instantiated with avfilter_graph_alloc_filter even if it
453 * is not registered.
3fa3e4f4 454 *
664f6595 455 * @param filter the filter to register
41ed7ab4 456 * @return 0 if the registration was successful, a negative value
86a60fa1 457 * otherwise
13ff8fd0 458 */
86a60fa1 459int avfilter_register(AVFilter *filter);
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460
461/**
49bd8e4b 462 * Get a filter definition matching the given name.
3fa3e4f4 463 *
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464 * @param name the filter name to find
465 * @return the filter definition, if any matching one is registered.
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466 * NULL if none found.
467 */
96a47364 468const AVFilter *avfilter_get_by_name(const char *name);
a5cbb2f4 469
13ff8fd0 470/**
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471 * Iterate over all registered filters.
472 * @return If prev is non-NULL, next registered filter after prev or NULL if
473 * prev is the last filter. If prev is NULL, return the first registered filter.
474 */
475const AVFilter *avfilter_next(const AVFilter *prev);
476
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477/**
478 * Initialize a filter with the supplied parameters.
479 *
480 * @param ctx uninitialized filter context to initialize
481 * @param args Options to initialize the filter with. This must be a
482 * ':'-separated list of options in the 'key=value' form.
483 * May be NULL if the options have been set directly using the
484 * AVOptions API or there are no options that need to be set.
485 * @return 0 on success, a negative AVERROR on failure
486 */
487int avfilter_init_str(AVFilterContext *ctx, const char *args);
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488
489/**
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490 * Initialize a filter with the supplied dictionary of options.
491 *
492 * @param ctx uninitialized filter context to initialize
493 * @param options An AVDictionary filled with options for this filter. On
494 * return this parameter will be destroyed and replaced with
495 * a dict containing options that were not found. This dictionary
496 * must be freed by the caller.
497 * May be NULL, then this function is equivalent to
498 * avfilter_init_str() with the second parameter set to NULL.
499 * @return 0 on success, a negative AVERROR on failure
500 *
501 * @note This function and avfilter_init_str() do essentially the same thing,
502 * the difference is in manner in which the options are passed. It is up to the
503 * calling code to choose whichever is more preferable. The two functions also
504 * behave differently when some of the provided options are not declared as
505 * supported by the filter. In such a case, avfilter_init_str() will fail, but
506 * this function will leave those extra options in the options AVDictionary and
507 * continue as usual.
508 */
509int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options);
510
511/**
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512 * Free a filter context. This will also remove the filter from its
513 * filtergraph's list of filters.
3fa3e4f4 514 *
24de0edb 515 * @param filter the filter to free
13ff8fd0 516 */
24de0edb 517void avfilter_free(AVFilterContext *filter);
a5cbb2f4 518
13ff8fd0 519/**
49bd8e4b 520 * Insert a filter in the middle of an existing link.
3fa3e4f4 521 *
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522 * @param link the link into which the filter should be inserted
523 * @param filt the filter to be inserted
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524 * @param filt_srcpad_idx the input pad on the filter to connect
525 * @param filt_dstpad_idx the output pad on the filter to connect
664f6595 526 * @return zero on success
13ff8fd0 527 */
35f3fdf4 528int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
486adc55 529 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
d3e57c15 530
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531/**
532 * @return AVClass for AVFilterContext.
533 *
534 * @see av_opt_find().
535 */
536const AVClass *avfilter_get_class(void);
537
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538typedef struct AVFilterGraphInternal AVFilterGraphInternal;
539
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540/**
541 * A function pointer passed to the @ref AVFilterGraph.execute callback to be
542 * executed multiple times, possibly in parallel.
543 *
544 * @param ctx the filter context the job belongs to
545 * @param arg an opaque parameter passed through from @ref
546 * AVFilterGraph.execute
547 * @param jobnr the index of the job being executed
548 * @param nb_jobs the total number of jobs
549 *
550 * @return 0 on success, a negative AVERROR on error
551 */
552typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
553
554/**
555 * A function executing multiple jobs, possibly in parallel.
556 *
557 * @param ctx the filter context to which the jobs belong
558 * @param func the function to be called multiple times
559 * @param arg the argument to be passed to func
560 * @param ret a nb_jobs-sized array to be filled with return values from each
561 * invocation of func
562 * @param nb_jobs the number of jobs to execute
563 *
564 * @return 0 on success, a negative AVERROR on error
565 */
566typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
567 void *arg, int *ret, int nb_jobs);
568
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569typedef struct AVFilterGraph {
570 const AVClass *av_class;
38f0c078 571 AVFilterContext **filters;
38f0c078 572 unsigned nb_filters;
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573
574 char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
575 char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
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576
577 /**
578 * Type of multithreading allowed for filters in this graph. A combination
579 * of AVFILTER_THREAD_* flags.
580 *
581 * May be set by the caller at any point, the setting will apply to all
582 * filters initialized after that. The default is allowing everything.
583 *
584 * When a filter in this graph is initialized, this field is combined using
585 * bit AND with AVFilterContext.thread_type to get the final mask used for
586 * determining allowed threading types. I.e. a threading type needs to be
587 * set in both to be allowed.
588 */
589 int thread_type;
590
591 /**
592 * Maximum number of threads used by filters in this graph. May be set by
593 * the caller before adding any filters to the filtergraph. Zero (the
594 * default) means that the number of threads is determined automatically.
595 */
596 int nb_threads;
597
598 /**
599 * Opaque object for libavfilter internal use.
600 */
601 AVFilterGraphInternal *internal;
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602
603 /**
604 * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
605 * be used from callbacks like @ref AVFilterGraph.execute.
606 * Libavfilter will not touch this field in any way.
607 */
608 void *opaque;
609
610 /**
611 * This callback may be set by the caller immediately after allocating the
612 * graph and before adding any filters to it, to provide a custom
613 * multithreading implementation.
614 *
615 * If set, filters with slice threading capability will call this callback
616 * to execute multiple jobs in parallel.
617 *
618 * If this field is left unset, libavfilter will use its internal
619 * implementation, which may or may not be multithreaded depending on the
620 * platform and build options.
621 */
622 avfilter_execute_func *execute;
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623} AVFilterGraph;
624
625/**
626 * Allocate a filter graph.
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627 *
628 * @return the allocated filter graph on success or NULL.
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629 */
630AVFilterGraph *avfilter_graph_alloc(void);
631
632/**
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633 * Create a new filter instance in a filter graph.
634 *
635 * @param graph graph in which the new filter will be used
636 * @param filter the filter to create an instance of
637 * @param name Name to give to the new instance (will be copied to
638 * AVFilterContext.name). This may be used by the caller to identify
639 * different filters, libavfilter itself assigns no semantics to
640 * this parameter. May be NULL.
641 *
642 * @return the context of the newly created filter instance (note that it is
643 * also retrievable directly through AVFilterGraph.filters or with
644 * avfilter_graph_get_filter()) on success or NULL or failure.
645 */
646AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
647 const AVFilter *filter,
648 const char *name);
649
650/**
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651 * Get a filter instance with name name from graph.
652 *
653 * @return the pointer to the found filter instance or NULL if it
654 * cannot be found.
655 */
656AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name);
657
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658/**
659 * Create and add a filter instance into an existing graph.
660 * The filter instance is created from the filter filt and inited
661 * with the parameters args and opaque.
662 *
663 * In case of success put in *filt_ctx the pointer to the created
664 * filter instance, otherwise set *filt_ctx to NULL.
665 *
666 * @param name the instance name to give to the created filter instance
667 * @param graph_ctx the filter graph
668 * @return a negative AVERROR error code in case of failure, a non
669 * negative value otherwise
670 */
77cc958f 671int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
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672 const char *name, const char *args, void *opaque,
673 AVFilterGraph *graph_ctx);
674
675/**
676 * Check validity and configure all the links and formats in the graph.
677 *
678 * @param graphctx the filter graph
679 * @param log_ctx context used for logging
680 * @return 0 in case of success, a negative AVERROR code otherwise
681 */
682int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
683
684/**
685 * Free a graph, destroy its links, and set *graph to NULL.
686 * If *graph is NULL, do nothing.
687 */
688void avfilter_graph_free(AVFilterGraph **graph);
689
690/**
691 * A linked-list of the inputs/outputs of the filter chain.
692 *
693 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
694 * where it is used to communicate open (unlinked) inputs and outputs from and
695 * to the caller.
696 * This struct specifies, per each not connected pad contained in the graph, the
697 * filter context and the pad index required for establishing a link.
698 */
699typedef struct AVFilterInOut {
700 /** unique name for this input/output in the list */
701 char *name;
702
703 /** filter context associated to this input/output */
704 AVFilterContext *filter_ctx;
705
706 /** index of the filt_ctx pad to use for linking */
707 int pad_idx;
708
709 /** next input/input in the list, NULL if this is the last */
710 struct AVFilterInOut *next;
711} AVFilterInOut;
712
713/**
714 * Allocate a single AVFilterInOut entry.
715 * Must be freed with avfilter_inout_free().
716 * @return allocated AVFilterInOut on success, NULL on failure.
717 */
718AVFilterInOut *avfilter_inout_alloc(void);
719
720/**
721 * Free the supplied list of AVFilterInOut and set *inout to NULL.
722 * If *inout is NULL, do nothing.
723 */
724void avfilter_inout_free(AVFilterInOut **inout);
725
726/**
727 * Add a graph described by a string to a graph.
728 *
729 * @param graph the filter graph where to link the parsed graph context
730 * @param filters string to be parsed
731 * @param inputs linked list to the inputs of the graph
732 * @param outputs linked list to the outputs of the graph
733 * @return zero on success, a negative AVERROR code on error
734 */
735int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
736 AVFilterInOut *inputs, AVFilterInOut *outputs,
737 void *log_ctx);
738
739/**
740 * Add a graph described by a string to a graph.
741 *
742 * @param[in] graph the filter graph where to link the parsed graph context
743 * @param[in] filters string to be parsed
744 * @param[out] inputs a linked list of all free (unlinked) inputs of the
745 * parsed graph will be returned here. It is to be freed
746 * by the caller using avfilter_inout_free().
747 * @param[out] outputs a linked list of all free (unlinked) outputs of the
748 * parsed graph will be returned here. It is to be freed by the
749 * caller using avfilter_inout_free().
750 * @return zero on success, a negative AVERROR code on error
751 *
752 * @note the difference between avfilter_graph_parse2() and
753 * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
754 * the lists of inputs and outputs, which therefore must be known before calling
755 * the function. On the other hand, avfilter_graph_parse2() \em returns the
756 * inputs and outputs that are left unlinked after parsing the graph and the
757 * caller then deals with them. Another difference is that in
758 * avfilter_graph_parse(), the inputs parameter describes inputs of the
759 * <em>already existing</em> part of the graph; i.e. from the point of view of
760 * the newly created part, they are outputs. Similarly the outputs parameter
761 * describes outputs of the already existing filters, which are provided as
762 * inputs to the parsed filters.
763 * avfilter_graph_parse2() takes the opposite approach -- it makes no reference
764 * whatsoever to already existing parts of the graph and the inputs parameter
765 * will on return contain inputs of the newly parsed part of the graph.
766 * Analogously the outputs parameter will contain outputs of the newly created
767 * filters.
768 */
769int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
770 AVFilterInOut **inputs,
771 AVFilterInOut **outputs);
772
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773/**
774 * @}
775 */
776
153382e1 777#endif /* AVFILTER_AVFILTER_H */