libavfilter/avfilter.h

   1 /*
   2  * filter layer
   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
  22 #ifndef AVFILTER_AVFILTER_H
  23 #define AVFILTER_AVFILTER_H
  24
  25 #define LIBAVFILTER_VERSION_MAJOR  0
  26 #define LIBAVFILTER_VERSION_MINOR  5
  27 #define LIBAVFILTER_VERSION_MICRO  0
  28
  29 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
  30                                                LIBAVFILTER_VERSION_MINOR, \
  31                                                LIBAVFILTER_VERSION_MICRO)
  32 #define LIBAVFILTER_VERSION     AV_VERSION(LIBAVFILTER_VERSION_MAJOR,   \
  33                                            LIBAVFILTER_VERSION_MINOR,   \
  34                                            LIBAVFILTER_VERSION_MICRO)
  35 #define LIBAVFILTER_BUILD       LIBAVFILTER_VERSION_INT
  36
  37 #include <stddef.h>
  38 #include "libavcodec/avcodec.h"
  39
  40 /**
  41  * Returns the LIBAVFILTER_VERSION_INT constant.
  42  */
  43 unsigned avfilter_version(void);
  44
  45 typedef struct AVFilterContext AVFilterContext;
  46 typedef struct AVFilterLink    AVFilterLink;
  47 typedef struct AVFilterPad     AVFilterPad;
  48
  49 /* TODO: look for other flags which may be useful in this structure (interlace
  50  * flags, etc)
  51  */
  52 /**
  53  * A reference-counted picture data type used by the filter system. Filters
  54  * should not store pointers to this structure directly, but instead use the
  55  * AVFilterPicRef structure below.
  56  */
  57 typedef struct AVFilterPic
  58 {
  59     uint8_t *data[4];           ///< picture data for each plane
  60     int linesize[4];            ///< number of bytes per line
  61     enum PixelFormat format;    ///< colorspace
  62
  63     unsigned refcount;          ///< number of references to this image
  64
  65     /** private data to be used by a custom free function */
  66     void *priv;
  67     /**
  68      * A pointer to the function to deallocate this image if the default
  69      * function is not sufficient. This could, for example, add the memory
  70      * back into a memory pool to be reused later without the overhead of
  71      * reallocating it from scratch.
  72      */
  73     void (*free)(struct AVFilterPic *pic);
  74 } AVFilterPic;
  75
  76 /**
  77  * A reference to an AVFilterPic. Since filters can manipulate the origin of
  78  * a picture to, for example, crop image without any memcpy, the picture origin
  79  * and dimensions are per-reference properties. Linesize is also useful for
  80  * image flipping, frame to field filters, etc, and so is also per-reference.
  81  *
  82  * TODO: add anything necessary for frame reordering
  83  */
  84 typedef struct AVFilterPicRef
  85 {
  86     AVFilterPic *pic;           ///< the picture that this is a reference to
  87     uint8_t *data[4];           ///< picture data for each plane
  88     int linesize[4];            ///< number of bytes per line
  89     int w;                      ///< image width
  90     int h;                      ///< image height
  91
  92     int64_t pts;                ///< presentation timestamp in units of 1/AV_TIME_BASE
  93
  94     AVRational pixel_aspect;    ///< pixel aspect ratio
  95
  96     int perms;                  ///< permissions
  97 #define AV_PERM_READ     0x01   ///< can read from the buffer
  98 #define AV_PERM_WRITE    0x02   ///< can write to the buffer
  99 #define AV_PERM_PRESERVE 0x04   ///< nobody else can overwrite the buffer
 100 #define AV_PERM_REUSE    0x08   ///< can output the buffer multiple times, with the same contents each time
 101 #define AV_PERM_REUSE2   0x10   ///< can output the buffer multiple times, modified each time
 102 } AVFilterPicRef;
 103
 104 /**
 105  * Adds a new reference to a picture.
 106  * @param ref   an existing reference to the picture
 107  * @param pmask a bitmask containing the allowable permissions in the new
 108  *              reference
 109  * @return      a new reference to the picture with the same properties as the
 110  *              old, excluding any permissions denied by pmask
 111  */
 112 AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
 113
 114 /**
 115  * Removes a reference to a picture. If this is the last reference to the
 116  * picture, the picture itself is also automatically freed.
 117  * @param ref reference to the picture
 118  */
 119 void avfilter_unref_pic(AVFilterPicRef *ref);
 120
 121 /**
 122  * A list of supported formats for one end of a filter link. This is used
 123  * during the format negotiation process to try to pick the best format to
 124  * use to minimize the number of necessary conversions. Each filter gives a
 125  * list of the formats supported by each input and output pad. The list
 126  * given for each pad need not be distinct - they may be references to the
 127  * same list of formats, as is often the case when a filter supports multiple
 128  * formats, but will always output the same format as it is given in input.
 129  *
 130  * In this way, a list of possible input formats and a list of possible
 131  * output formats are associated with each link. When a set of formats is
 132  * negotiated over a link, the input and output lists are merged to form a
 133  * new list containing only the common elements of each list. In the case
 134  * that there were no common elements, a format conversion is necessary.
 135  * Otherwise, the lists are merged, and all other links which reference
 136  * either of the format lists involved in the merge are also affected.
 137  *
 138  * For example, consider the filter chain:
 139  * filter (a) --> (b) filter (b) --> (c) filter
 140  *
 141  * where the letters in parenthesis indicate a list of formats supported on
 142  * the input or output of the link. Suppose the lists are as follows:
 143  * (a) = {A, B}
 144  * (b) = {A, B, C}
 145  * (c) = {B, C}
 146  *
 147  * First, the first link's lists are merged, yielding:
 148  * filter (a) --> (a) filter (a) --> (c) filter
 149  *
 150  * Notice that format list (b) now refers to the same list as filter list (a).
 151  * Next, the lists for the second link are merged, yielding:
 152  * filter (a) --> (a) filter (a) --> (a) filter
 153  *
 154  * where (a) = {B}.
 155  *
 156  * Unfortunately, when the format lists at the two ends of a link are merged,
 157  * we must ensure that all links which reference either pre-merge format list
 158  * get updated as well. Therefore, we have the format list structure store a
 159  * pointer to each of the pointers to itself.
 160  */
 161 typedef struct AVFilterFormats AVFilterFormats;
 162 struct AVFilterFormats
 163 {
 164     unsigned format_count;      ///< number of formats
 165     int *formats;               ///< list of formats
 166
 167     unsigned refcount;          ///< number of references to this list
 168     AVFilterFormats ***refs;    ///< references to this list
 169 };
 170
 171 /**
 172  * Helper function to create a list of supported formats.  This is intended
 173  * for use in AVFilter->query_formats().
 174  * @param len the number of formats supported
 175  * @param ... a list of the supported formats
 176  * @return    the format list, with no existing references
 177  */
 178 AVFilterFormats *avfilter_make_format_list(int len, ...);
 179
 180 /**
 181  * Returns a list of all colorspaces supported by FFmpeg.
 182  */
 183 AVFilterFormats *avfilter_all_colorspaces(void);
 184
 185 /**
 186  * Returns a format list which contains the intersection of the formats of
 187  * a and b. Also, all the references of a, all the references of b, and
 188  * a and b themselves will be deallocated.
 189  *
 190  * If a and b do not share any common formats, neither is modified, and NULL
 191  * is returned.
 192  */
 193 AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
 194
 195 /**
 196  * Adds *ref as a new reference to formats.
 197  * That is the pointers will point like in the ascii art below:
 198  *   ________
 199  *  |formats |<--------.
 200  *  |  ____  |     ____|___________________
 201  *  | |refs| |    |  __|_
 202  *  | |* * | |    | |  | |  AVFilterLink
 203  *  | |* *--------->|*ref|
 204  *  | |____| |    | |____|
 205  *  |________|    |________________________
 206  */
 207 void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
 208
 209 /**
 210  * Removes *ref as a reference to the format list it currently points to,
 211  * deallocates that list if this was the last reference, and sets *ref to NULL.
 212  *
 213  *         Before                                 After
 214  *   ________                               ________         NULL
 215  *  |formats |<--------.                   |formats |         ^
 216  *  |  ____  |     ____|________________   |  ____  |     ____|________________
 217  *  | |refs| |    |  __|_                  | |refs| |    |  __|_
 218  *  | |* * | |    | |  | |  AVFilterLink   | |* * | |    | |  | |  AVFilterLink
 219  *  | |* *--------->|*ref|                 | |*   | |    | |*ref|
 220  *  | |____| |    | |____|                 | |____| |    | |____|
 221  *  |________|    |_____________________   |________|    |_____________________
 222  */
 223 void avfilter_formats_unref(AVFilterFormats **ref);
 224
 225 /**
 226  *
 227  *         Before                                 After
 228  *   ________                         ________
 229  *  |formats |<---------.            |formats |<---------.
 230  *  |  ____  |       ___|___         |  ____  |       ___|___
 231  *  | |refs| |      |   |   |        | |refs| |      |   |   |   NULL
 232  *  | |* *--------->|*oldref|        | |* *--------->|*newref|     ^
 233  *  | |* * | |      |_______|        | |* * | |      |_______|  ___|___
 234  *  | |____| |                       | |____| |                |   |   |
 235  *  |________|                       |________|                |*oldref|
 236  *                                                             |_______|
 237  */
 238 void avfilter_formats_changeref(AVFilterFormats **oldref,
 239                                 AVFilterFormats **newref);
 240
 241 /**
 242  * A filter pad used for either input or output.
 243  */
 244 struct AVFilterPad
 245 {
 246     /**
 247      * Pad name. The name is unique among inputs and among outputs, but an
 248      * input may have the same name as an output. This may be NULL if this
 249      * pad has no need to ever be referenced by name.
 250      */
 251     const char *name;
 252
 253     /**
 254      * AVFilterPad type. Only video supported now, hopefully someone will
 255      * add audio in the future.
 256      */
 257     enum CodecType type;
 258
 259     /**
 260      * Minimum required permissions on incoming buffers. Any buffer with
 261      * insufficient permissions will be automatically copied by the filter
 262      * system to a new buffer which provides the needed access permissions.
 263      *
 264      * Input pads only.
 265      */
 266     int min_perms;
 267
 268     /**
 269      * Permissions which are not accepted on incoming buffers. Any buffer
 270      * which has any of these permissions set will be automatically copied
 271      * by the filter system to a new buffer which does not have those
 272      * permissions. This can be used to easily disallow buffers with
 273      * AV_PERM_REUSE.
 274      *
 275      * Input pads only.
 276      */
 277     int rej_perms;
 278
 279     /**
 280      * Callback called before passing the first slice of a new frame. If
 281      * NULL, the filter layer will default to storing a reference to the
 282      * picture inside the link structure.
 283      *
 284      * Input video pads only.
 285      */
 286     void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
 287
 288     /**
 289      * Callback function to get a buffer. If NULL, the filter system will
 290      * handle buffer requests.
 291      *
 292      * Input video pads only.
 293      */
 294     AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms);
 295
 296     /**
 297      * Callback called after the slices of a frame are completely sent. If
 298      * NULL, the filter layer will default to releasing the reference stored
 299      * in the link structure during start_frame().
 300      *
 301      * Input video pads only.
 302      */
 303     void (*end_frame)(AVFilterLink *link);
 304
 305     /**
 306      * Slice drawing callback. This is where a filter receives video data
 307      * and should do its processing.
 308      *
 309      * Input video pads only.
 310      */
 311     void (*draw_slice)(AVFilterLink *link, int y, int height);
 312
 313     /**
 314      * Frame poll callback. This returns the number of immediately available
 315      * frames. It should return a positive value if the next request_frame()
 316      * is guaranteed to return one frame (with no delay).
 317      *
 318      * Defaults to just calling the source poll_frame() method.
 319      *
 320      * Output video pads only.
 321      */
 322     int (*poll_frame)(AVFilterLink *link);
 323
 324     /**
 325      * Frame request callback. A call to this should result in at least one
 326      * frame being output over the given link. This should return zero on
 327      * success, and another value on error.
 328      *
 329      * Output video pads only.
 330      */
 331     int (*request_frame)(AVFilterLink *link);
 332
 333     /**
 334      * Link configuration callback.
 335      *
 336      * For output pads, this should set the link properties such as
 337      * width/height. This should NOT set the format property - that is
 338      * negotiated between filters by the filter system using the
 339      * query_formats() callback before this function is called.
 340      *
 341      * For input pads, this should check the properties of the link, and update
 342      * the filter's internal state as necessary.
 343      *
 344      * For both input and output filters, this should return zero on success,
 345      * and another value on error.
 346      */
 347     int (*config_props)(AVFilterLink *link);
 348 };
 349
 350 /** default handler for start_frame() for video inputs */
 351 void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
 352 /** default handler for draw_slice() for video inputs */
 353 void avfilter_default_draw_slice(AVFilterLink *link, int y, int h);
 354 /** default handler for end_frame() for video inputs */
 355 void avfilter_default_end_frame(AVFilterLink *link);
 356 /** default handler for config_props() for video outputs */
 357 int avfilter_default_config_output_link(AVFilterLink *link);
 358 /** default handler for config_props() for video inputs */
 359 int avfilter_default_config_input_link (AVFilterLink *link);
 360 /** default handler for get_video_buffer() for video inputs */
 361 AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
 362                                                   int perms);
 363 /**
 364  * A helper for query_formats() which sets all links to the same list of
 365  * formats. If there are no links hooked to this filter, the list of formats is
 366  * freed.
 367  */
 368 void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
 369 /** Default handler for query_formats() */
 370 int avfilter_default_query_formats(AVFilterContext *ctx);
 371
 372 /**
 373  * Filter definition. This defines the pads a filter contains, and all the
 374  * callback functions used to interact with the filter.
 375  */
 376 typedef struct
 377 {
 378     const char *name;         ///< filter name
 379
 380     int priv_size;      ///< size of private data to allocate for the filter
 381
 382     /**
 383      * Filter initialization function. Args contains the user-supplied
 384      * parameters. FIXME: maybe an AVOption-based system would be better?
 385      * opaque is data provided by the code requesting creation of the filter,
 386      * and is used to pass data to the filter.
 387      */
 388     int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
 389
 390     /**
 391      * Filter uninitialization function. Should deallocate any memory held
 392      * by the filter, release any picture references, etc. This does not need
 393      * to deallocate the AVFilterContext->priv memory itself.
 394      */
 395     void (*uninit)(AVFilterContext *ctx);
 396
 397     /**
 398      * Query formats supported by the filter and its pads. Should set the
 399      * in_formats for links connected to its output pads, and out_formats
 400      * for links connected to its input pads.
 401      *
 402      * Should return zero on success.
 403      */
 404     int (*query_formats)(AVFilterContext *);
 405
 406     const AVFilterPad *inputs;  ///< NULL terminated list of inputs. NULL if none
 407     const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
 408 } AVFilter;
 409
 410 /** An instance of a filter */
 411 struct AVFilterContext
 412 {
 413     const AVClass *av_class;              ///< needed for av_log()
 414
 415     AVFilter *filter;               ///< the AVFilter of which this is an instance
 416
 417     char *name;                     ///< name of this filter instance
 418
 419     unsigned input_count;           ///< number of input pads
 420     AVFilterPad   *input_pads;      ///< array of input pads
 421     AVFilterLink **inputs;          ///< array of pointers to input links
 422
 423     unsigned output_count;          ///< number of output pads
 424     AVFilterPad   *output_pads;     ///< array of output pads
 425     AVFilterLink **outputs;         ///< array of pointers to output links
 426
 427     void *priv;                     ///< private data for use by the filter
 428 };
 429
 430 /**
 431  * A link between two filters. This contains pointers to the source and
 432  * destination filters between which this link exists, and the indexes of
 433  * the pads involved. In addition, this link also contains the parameters
 434  * which have been negotiated and agreed upon between the filter, such as
 435  * image dimensions, format, etc.
 436  */
 437 struct AVFilterLink
 438 {
 439     AVFilterContext *src;       ///< source filter
 440     unsigned int srcpad;        ///< index of the output pad on the source filter
 441
 442     AVFilterContext *dst;       ///< dest filter
 443     unsigned int dstpad;        ///< index of the input pad on the dest filter
 444
 445     /** stage of the initialization of the link properties (dimensions, etc) */
 446     enum {
 447         AVLINK_UNINIT = 0,      ///< not started
 448         AVLINK_STARTINIT,       ///< started, but incomplete
 449         AVLINK_INIT             ///< complete
 450     } init_state;
 451
 452     int w;                      ///< agreed upon image width
 453     int h;                      ///< agreed upon image height
 454     enum PixelFormat format;    ///< agreed upon image colorspace
 455
 456     /**
 457      * Lists of formats supported by the input and output filters respectively.
 458      * These lists are used for negotiating the format to actually be used,
 459      * which will be loaded into the format member, above, when chosen.
 460      */
 461     AVFilterFormats *in_formats;
 462     AVFilterFormats *out_formats;
 463
 464     /**
 465      * The picture reference currently being sent across the link by the source
 466      * filter. This is used internally by the filter system to allow
 467      * automatic copying of pictures which do not have sufficient permissions
 468      * for the destination. This should not be accessed directly by the
 469      * filters.
 470      */
 471     AVFilterPicRef *srcpic;
 472
 473     AVFilterPicRef *cur_pic;
 474     AVFilterPicRef *outpic;
 475 };
 476
 477 /**
 478  * Links two filters together.
 479  * @param src    the source filter
 480  * @param srcpad index of the output pad on the source filter
 481  * @param dst    the destination filter
 482  * @param dstpad index of the input pad on the destination filter
 483  * @return       zero on success
 484  */
 485 int avfilter_link(AVFilterContext *src, unsigned srcpad,
 486                   AVFilterContext *dst, unsigned dstpad);
 487
 488 /**
 489  * Negotiates the colorspace, dimensions, etc of all inputs to a filter.
 490  * @param filter the filter to negotiate the properties for its inputs
 491  * @return       zero on successful negotiation
 492  */
 493 int avfilter_config_links(AVFilterContext *filter);
 494
 495 /**
 496  * Requests a picture buffer with a specific set of permissions.
 497  * @param link  the output link to the filter from which the picture will
 498  *              be requested
 499  * @param perms the required access permissions
 500  * @return      A reference to the picture. This must be unreferenced with
 501  *              avfilter_unref_pic when you are finished with it.
 502  */
 503 AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);
 504
 505 /**
 506  * Requests an input frame from the filter at the other end of the link.
 507  * @param link the input link
 508  * @return     zero on success
 509  */
 510 int avfilter_request_frame(AVFilterLink *link);
 511
 512 /**
 513  * Polls a frame from the filter chain.
 514  * @param  link the input link
 515  * @return the number of immediately available frames, a negative
 516  * number in case of error
 517  */
 518 int avfilter_poll_frame(AVFilterLink *link);
 519
 520 /**
 521  * Notifies the next filter of the start of a frame.
 522  * @param link   the output link the frame will be sent over
 523  * @param picref A reference to the frame about to be sent. The data for this
 524  *               frame need only be valid once draw_slice() is called for that
 525  *               portion. The receiving filter will free this reference when
 526  *               it no longer needs it.
 527  */
 528 void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
 529
 530 /**
 531  * Notifies the next filter that the current frame has finished.
 532  * @param link the output link the frame was sent over
 533  */
 534 void avfilter_end_frame(AVFilterLink *link);
 535
 536 /**
 537  * Sends a slice to the next filter.
 538  * @param link the output link over which the frame is being sent
 539  * @param y    offset in pixels from the top of the image for this slice
 540  * @param h    height of this slice in pixels
 541  */
 542 void avfilter_draw_slice(AVFilterLink *link, int y, int h);
 543
 544 /** Initialize the filter system. Registers all builtin filters */
 545 void avfilter_register_all(void);
 546
 547 /** Uninitialize the filter system. Unregisters all filters */
 548 void avfilter_uninit(void);
 549
 550 /**
 551  * Registers a filter. This is only needed if you plan to use
 552  * avfilter_get_by_name later to lookup the AVFilter structure by name. A
 553  * filter can still by instantiated with avfilter_open even if it is not
 554  * registered.
 555  * @param filter the filter to register
 556  */
 557 void avfilter_register(AVFilter *filter);
 558
 559 /**
 560  * Gets a filter definition matching the given name.
 561  * @param name the filter name to find
 562  * @return     the filter definition, if any matching one is registered.
 563  *             NULL if none found.
 564  */
 565 AVFilter *avfilter_get_by_name(const char *name);
 566
 567 /**
 568  * Creates a filter instance.
 569  * @param filter    the filter to create an instance of
 570  * @param inst_name Name to give to the new instance. Can be NULL for none.
 571  * @return          Pointer to the new instance on success. NULL on failure.
 572  */
 573 AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
 574
 575 /**
 576  * Initializes a filter.
 577  * @param filter the filter to initialize
 578  * @param args   A string of parameters to use when initializing the filter.
 579  *               The format and meaning of this string varies by filter.
 580  * @param opaque Any extra non-string data needed by the filter. The meaning
 581  *               of this parameter varies by filter.
 582  * @return       zero on success
 583  */
 584 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
 585
 586 /**
 587  * Destroys a filter.
 588  * @param filter the filter to destroy
 589  */
 590 void avfilter_destroy(AVFilterContext *filter);
 591
 592 /**
 593  * Inserts a filter in the middle of an existing link.
 594  * @param link the link into which the filter should be inserted
 595  * @param filt the filter to be inserted
 596  * @param in   the input pad on the filter to connect
 597  * @param out  the output pad on the filter to connect
 598  * @return     zero on success
 599  */
 600 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
 601                            unsigned in, unsigned out);
 602
 603 /**
 604  * Inserts a new pad.
 605  * @param idx Insertion point. Pad is inserted at the end if this point
 606  *            is beyond the end of the list of pads.
 607  * @param count Pointer to the number of pads in the list
 608  * @param padidx_off Offset within an AVFilterLink structure to the element
 609  *                   to increment when inserting a new pad causes link
 610  *                   numbering to change
 611  * @param pads Pointer to the pointer to the beginning of the list of pads
 612  * @param links Pointer to the pointer to the beginning of the list of links
 613  * @param newpad The new pad to add. A copy is made when adding.
 614  */
 615 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
 616                          AVFilterPad **pads, AVFilterLink ***links,
 617                          AVFilterPad *newpad);
 618
 619 /** Inserts a new input pad for the filter. */
 620 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
 621                                          AVFilterPad *p)
 622 {
 623     avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
 624                         &f->input_pads, &f->inputs, p);
 625 }
 626
 627 /** Inserts a new output pad for the filter. */
 628 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
 629                                           AVFilterPad *p)
 630 {
 631     avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
 632                         &f->output_pads, &f->outputs, p);
 633 }
 634
 635 #endif  /* AVFILTER_AVFILTER_H */