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/*
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 * filter layer
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 * copyright (c) 2007 Bobby Bingham
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#ifndef AVFILTER_AVFILTER_H
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#define AVFILTER_AVFILTER_H
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#include "libavutil/avutil.h"
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#define LIBAVFILTER_VERSION_MAJOR  1
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#define LIBAVFILTER_VERSION_MINOR  8
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#define LIBAVFILTER_VERSION_MICRO  0
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#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
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                                               LIBAVFILTER_VERSION_MINOR, \
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                                               LIBAVFILTER_VERSION_MICRO)
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#define LIBAVFILTER_VERSION     AV_VERSION(LIBAVFILTER_VERSION_MAJOR,   \
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                                           LIBAVFILTER_VERSION_MINOR,   \
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                                           LIBAVFILTER_VERSION_MICRO)
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#define LIBAVFILTER_BUILD       LIBAVFILTER_VERSION_INT
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#include <stddef.h>
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#include "libavcodec/avcodec.h"
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/**
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 * Returns the LIBAVFILTER_VERSION_INT constant.
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 */
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unsigned avfilter_version(void);
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/**
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 * Returns the libavfilter build-time configuration.
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 */
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const char * avfilter_configuration(void);
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/**
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 * Returns the libavfilter license.
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 */
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const char * avfilter_license(void);
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typedef struct AVFilterContext AVFilterContext;
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typedef struct AVFilterLink    AVFilterLink;
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typedef struct AVFilterPad     AVFilterPad;
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/* TODO: look for other flags which may be useful in this structure (interlace
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 * flags, etc)
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 */
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/**
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 * A reference-counted picture data type used by the filter system. Filters
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 * should not store pointers to this structure directly, but instead use the
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 * AVFilterPicRef structure below.
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 */
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typedef struct AVFilterPic
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{
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    uint8_t *data[4];           ///< picture data for each plane
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    int linesize[4];            ///< number of bytes per line
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    enum PixelFormat format;    ///< colorspace
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    unsigned refcount;          ///< number of references to this image
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    /** private data to be used by a custom free function */
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    void *priv;
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    /**
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     * A pointer to the function to deallocate this image if the default
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     * function is not sufficient. This could, for example, add the memory
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     * back into a memory pool to be reused later without the overhead of
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     * reallocating it from scratch.
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     */
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    void (*free)(struct AVFilterPic *pic);
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    int w, h;                  ///< width and height of the allocated buffer
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} AVFilterPic;
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/**
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 * A reference to an AVFilterPic. Since filters can manipulate the origin of
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 * a picture to, for example, crop image without any memcpy, the picture origin
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 * and dimensions are per-reference properties. Linesize is also useful for
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 * image flipping, frame to field filters, etc, and so is also per-reference.
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 *
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 * TODO: add anything necessary for frame reordering
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 */
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typedef struct AVFilterPicRef
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{
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    AVFilterPic *pic;           ///< the picture that this is a reference to
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    uint8_t *data[4];           ///< picture data for each plane
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    int linesize[4];            ///< number of bytes per line
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    int w;                      ///< image width
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    int h;                      ///< image height
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    int64_t pts;                ///< presentation timestamp in units of 1/AV_TIME_BASE
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    AVRational pixel_aspect;    ///< pixel aspect ratio
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    int perms;                  ///< permissions
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#define AV_PERM_READ     0x01   ///< can read from the buffer
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#define AV_PERM_WRITE    0x02   ///< can write to the buffer
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#define AV_PERM_PRESERVE 0x04   ///< nobody else can overwrite the buffer
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#define AV_PERM_REUSE    0x08   ///< can output the buffer multiple times, with the same contents each time
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#define AV_PERM_REUSE2   0x10   ///< can output the buffer multiple times, modified each time
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} AVFilterPicRef;
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/**
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 * Adds a new reference to a picture.
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 * @param ref   an existing reference to the picture
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 * @param pmask a bitmask containing the allowable permissions in the new
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 *              reference
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 * @return      a new reference to the picture with the same properties as the
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 *              old, excluding any permissions denied by pmask
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 */
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AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
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/**
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 * Removes a reference to a picture. If this is the last reference to the
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 * picture, the picture itself is also automatically freed.
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 * @param ref reference to the picture
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 */
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void avfilter_unref_pic(AVFilterPicRef *ref);
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/**
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 * A list of supported formats for one end of a filter link. This is used
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 * during the format negotiation process to try to pick the best format to
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 * use to minimize the number of necessary conversions. Each filter gives a
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 * list of the formats supported by each input and output pad. The list
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 * given for each pad need not be distinct - they may be references to the
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 * same list of formats, as is often the case when a filter supports multiple
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 * formats, but will always output the same format as it is given in input.
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 *
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 * In this way, a list of possible input formats and a list of possible
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 * output formats are associated with each link. When a set of formats is
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 * negotiated over a link, the input and output lists are merged to form a
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 * new list containing only the common elements of each list. In the case
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 * that there were no common elements, a format conversion is necessary.
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 * Otherwise, the lists are merged, and all other links which reference
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 * either of the format lists involved in the merge are also affected.
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 *
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 * For example, consider the filter chain:
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 * filter (a) --> (b) filter (b) --> (c) filter
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 *
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 * where the letters in parenthesis indicate a list of formats supported on
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 * the input or output of the link. Suppose the lists are as follows:
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 * (a) = {A, B}
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 * (b) = {A, B, C}
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 * (c) = {B, C}
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 *
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 * First, the first link's lists are merged, yielding:
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 * filter (a) --> (a) filter (a) --> (c) filter
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 *
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 * Notice that format list (b) now refers to the same list as filter list (a).
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 * Next, the lists for the second link are merged, yielding:
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 * filter (a) --> (a) filter (a) --> (a) filter
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 *
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 * where (a) = {B}.
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 *
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 * Unfortunately, when the format lists at the two ends of a link are merged,
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 * we must ensure that all links which reference either pre-merge format list
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 * get updated as well. Therefore, we have the format list structure store a
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 * pointer to each of the pointers to itself.
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 */
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typedef struct AVFilterFormats AVFilterFormats;
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struct AVFilterFormats
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{
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    unsigned format_count;      ///< number of formats
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    enum PixelFormat *formats;  ///< list of pixel formats
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    unsigned refcount;          ///< number of references to this list
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    AVFilterFormats ***refs;    ///< references to this list
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};
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/**
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 * Creates a list of supported formats. This is intended for use in
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 * AVFilter->query_formats().
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 * @param pix_fmt list of pixel formats, terminated by PIX_FMT_NONE
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 * @return the format list, with no existing references
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 */
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AVFilterFormats *avfilter_make_format_list(const enum PixelFormat *pix_fmts);
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/**
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 * Returns a list of all colorspaces supported by FFmpeg.
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 */
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AVFilterFormats *avfilter_all_colorspaces(void);
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/**
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 * Returns a format list which contains the intersection of the formats of
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 * a and b. Also, all the references of a, all the references of b, and
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 * a and b themselves will be deallocated.
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 *
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 * If a and b do not share any common formats, neither is modified, and NULL
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 * is returned.
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 */
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AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
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/**
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 * Adds *ref as a new reference to formats.
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 * That is the pointers will point like in the ascii art below:
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 *   ________
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 *  |formats |<--------.
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 *  |  ____  |     ____|___________________
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 *  | |refs| |    |  __|_
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 *  | |* * | |    | |  | |  AVFilterLink
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 *  | |* *--------->|*ref|
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 *  | |____| |    | |____|
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 *  |________|    |________________________
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 */
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void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
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/**
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 * Removes *ref as a reference to the format list it currently points to,
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 * deallocates that list if this was the last reference, and sets *ref to NULL.
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 *
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 *         Before                                 After
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 *   ________                               ________         NULL
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 *  |formats |<--------.                   |formats |         ^
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 *  |  ____  |     ____|________________   |  ____  |     ____|________________
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 *  | |refs| |    |  __|_                  | |refs| |    |  __|_
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 *  | |* * | |    | |  | |  AVFilterLink   | |* * | |    | |  | |  AVFilterLink
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 *  | |* *--------->|*ref|                 | |*   | |    | |*ref|
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 *  | |____| |    | |____|                 | |____| |    | |____|
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 *  |________|    |_____________________   |________|    |_____________________
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 */
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void avfilter_formats_unref(AVFilterFormats **ref);
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/**
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 *
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 *         Before                                 After
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 *   ________                         ________
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 *  |formats |<---------.            |formats |<---------.
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 *  |  ____  |       ___|___         |  ____  |       ___|___
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 *  | |refs| |      |   |   |        | |refs| |      |   |   |   NULL
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 *  | |* *--------->|*oldref|        | |* *--------->|*newref|     ^
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 *  | |* * | |      |_______|        | |* * | |      |_______|  ___|___
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 *  | |____| |                       | |____| |                |   |   |
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 *  |________|                       |________|                |*oldref|
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 *                                                             |_______|
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 */
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void avfilter_formats_changeref(AVFilterFormats **oldref,
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                                AVFilterFormats **newref);
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/**
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 * A filter pad used for either input or output.
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 */
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struct AVFilterPad
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{
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    /**
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     * Pad name. The name is unique among inputs and among outputs, but an
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     * input may have the same name as an output. This may be NULL if this
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     * pad has no need to ever be referenced by name.
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     */
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    const char *name;
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    /**
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     * AVFilterPad type. Only video supported now, hopefully someone will
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     * add audio in the future.
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     */
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    enum CodecType type;
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    /**
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     * Minimum required permissions on incoming buffers. Any buffer with
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     * insufficient permissions will be automatically copied by the filter
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     * system to a new buffer which provides the needed access permissions.
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     *
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     * Input pads only.
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     */
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    int min_perms;
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    /**
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     * Permissions which are not accepted on incoming buffers. Any buffer
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     * which has any of these permissions set will be automatically copied
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     * by the filter system to a new buffer which does not have those
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     * permissions. This can be used to easily disallow buffers with
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     * AV_PERM_REUSE.
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     *
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     * Input pads only.
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     */
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    int rej_perms;
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    /**
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     * Callback called before passing the first slice of a new frame. If
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     * NULL, the filter layer will default to storing a reference to the
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     * picture inside the link structure.
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     *
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     * Input video pads only.
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     */
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    void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
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    /**
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     * Callback function to get a buffer. If NULL, the filter system will
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     * use avfilter_default_get_video_buffer().
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     *
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     * Input video pads only.
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     */
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    AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
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    /**
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     * Callback called after the slices of a frame are completely sent. If
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     * NULL, the filter layer will default to releasing the reference stored
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     * in the link structure during start_frame().
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     *
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     * Input video pads only.
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     */
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    void (*end_frame)(AVFilterLink *link);
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    /**
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     * Slice drawing callback. This is where a filter receives video data
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     * and should do its processing.
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     *
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     * Input video pads only.
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     */
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    void (*draw_slice)(AVFilterLink *link, int y, int height);
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    /**
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     * Frame poll callback. This returns the number of immediately available
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     * frames. It should return a positive value if the next request_frame()
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     * is guaranteed to return one frame (with no delay).
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     *
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     * Defaults to just calling the source poll_frame() method.
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     *
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     * Output video pads only.
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     */
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    int (*poll_frame)(AVFilterLink *link);
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    /**
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     * Frame request callback. A call to this should result in at least one
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     * frame being output over the given link. This should return zero on
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     * success, and another value on error.
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     *
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     * Output video pads only.
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     */
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    int (*request_frame)(AVFilterLink *link);
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    /**
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     * Link configuration callback.
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     *
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     * For output pads, this should set the link properties such as
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     * width/height. This should NOT set the format property - that is
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     * negotiated between filters by the filter system using the
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     * query_formats() callback before this function is called.
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     *
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     * For input pads, this should check the properties of the link, and update
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     * the filter's internal state as necessary.
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     *
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     * For both input and output filters, this should return zero on success,
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     * and another value on error.
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     */
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    int (*config_props)(AVFilterLink *link);
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};
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/** default handler for start_frame() for video inputs */
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void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
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/** default handler for draw_slice() for video inputs */
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void avfilter_default_draw_slice(AVFilterLink *link, int y, int h);
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/** default handler for end_frame() for video inputs */
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void avfilter_default_end_frame(AVFilterLink *link);
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/** default handler for config_props() for video outputs */
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int avfilter_default_config_output_link(AVFilterLink *link);
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/** default handler for config_props() for video inputs */
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int avfilter_default_config_input_link (AVFilterLink *link);
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/** default handler for get_video_buffer() for video inputs */
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AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
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                                                  int perms, int w, int h);
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/**
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 * A helper for query_formats() which sets all links to the same list of
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 * formats. If there are no links hooked to this filter, the list of formats is
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 * freed.
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 */
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void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
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/** Default handler for query_formats() */
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int avfilter_default_query_formats(AVFilterContext *ctx);
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/**
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 * Filter definition. This defines the pads a filter contains, and all the
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 * callback functions used to interact with the filter.
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 */
390
typedef struct AVFilter
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{
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    const char *name;         ///< filter name
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    int priv_size;      ///< size of private data to allocate for the filter
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    /**
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     * Filter initialization function. Args contains the user-supplied
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     * parameters. FIXME: maybe an AVOption-based system would be better?
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     * opaque is data provided by the code requesting creation of the filter,
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     * and is used to pass data to the filter.
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     */
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    int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
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    /**
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     * Filter uninitialization function. Should deallocate any memory held
406
     * by the filter, release any picture references, etc. This does not need
407
     * to deallocate the AVFilterContext->priv memory itself.
408
     */
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    void (*uninit)(AVFilterContext *ctx);
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    /**
412
     * Query formats supported by the filter and its pads. Should set the
413
     * in_formats for links connected to its output pads, and out_formats
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     * for links connected to its input pads.
415
     *
416
     * Should return zero on success.
417
     */
418
    int (*query_formats)(AVFilterContext *);
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    const AVFilterPad *inputs;  ///< NULL terminated list of inputs. NULL if none
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    const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
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    /**
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     * A description for the filter. You should use the
425
     * NULL_IF_CONFIG_SMALL() macro to define it.
426
     */
427
    const char *description;
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    /**
430
     * The next registered filter, NULL if this is the last one.
431
     */
432
    struct AVFilter *next;
433
} AVFilter;
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/** An instance of a filter */
436
struct AVFilterContext
437
{
438
    const AVClass *av_class;              ///< needed for av_log()
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440
    AVFilter *filter;               ///< the AVFilter of which this is an instance
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    char *name;                     ///< name of this filter instance
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    unsigned input_count;           ///< number of input pads
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    AVFilterPad   *input_pads;      ///< array of input pads
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    AVFilterLink **inputs;          ///< array of pointers to input links
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448
    unsigned output_count;          ///< number of output pads
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    AVFilterPad   *output_pads;     ///< array of output pads
450
    AVFilterLink **outputs;         ///< array of pointers to output links
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452
    void *priv;                     ///< private data for use by the filter
453
};
454

    
455
/**
456
 * A link between two filters. This contains pointers to the source and
457
 * destination filters between which this link exists, and the indexes of
458
 * the pads involved. In addition, this link also contains the parameters
459
 * which have been negotiated and agreed upon between the filter, such as
460
 * image dimensions, format, etc.
461
 */
462
struct AVFilterLink
463
{
464
    AVFilterContext *src;       ///< source filter
465
    unsigned int srcpad;        ///< index of the output pad on the source filter
466

    
467
    AVFilterContext *dst;       ///< dest filter
468
    unsigned int dstpad;        ///< index of the input pad on the dest filter
469

    
470
    /** stage of the initialization of the link properties (dimensions, etc) */
471
    enum {
472
        AVLINK_UNINIT = 0,      ///< not started
473
        AVLINK_STARTINIT,       ///< started, but incomplete
474
        AVLINK_INIT             ///< complete
475
    } init_state;
476

    
477
    int w;                      ///< agreed upon image width
478
    int h;                      ///< agreed upon image height
479
    enum PixelFormat format;    ///< agreed upon image colorspace
480

    
481
    /**
482
     * Lists of formats supported by the input and output filters respectively.
483
     * These lists are used for negotiating the format to actually be used,
484
     * which will be loaded into the format member, above, when chosen.
485
     */
486
    AVFilterFormats *in_formats;
487
    AVFilterFormats *out_formats;
488

    
489
    /**
490
     * The picture reference currently being sent across the link by the source
491
     * filter. This is used internally by the filter system to allow
492
     * automatic copying of pictures which do not have sufficient permissions
493
     * for the destination. This should not be accessed directly by the
494
     * filters.
495
     */
496
    AVFilterPicRef *srcpic;
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498
    AVFilterPicRef *cur_pic;
499
    AVFilterPicRef *outpic;
500
};
501

    
502
/**
503
 * Links two filters together.
504
 * @param src    the source filter
505
 * @param srcpad index of the output pad on the source filter
506
 * @param dst    the destination filter
507
 * @param dstpad index of the input pad on the destination filter
508
 * @return       zero on success
509
 */
510
int avfilter_link(AVFilterContext *src, unsigned srcpad,
511
                  AVFilterContext *dst, unsigned dstpad);
512

    
513
/**
514
 * Negotiates the colorspace, dimensions, etc of all inputs to a filter.
515
 * @param filter the filter to negotiate the properties for its inputs
516
 * @return       zero on successful negotiation
517
 */
518
int avfilter_config_links(AVFilterContext *filter);
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520
/**
521
 * Requests a picture buffer with a specific set of permissions.
522
 * @param link  the output link to the filter from which the picture will
523
 *              be requested
524
 * @param perms the required access permissions
525
 * @param w     the minimum width of the buffer to allocate
526
 * @param h     the minimum height of the buffer to allocate
527
 * @return      A reference to the picture. This must be unreferenced with
528
 *              avfilter_unref_pic when you are finished with it.
529
 */
530
AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
531
                                          int w, int h);
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533
/**
534
 * Requests an input frame from the filter at the other end of the link.
535
 * @param link the input link
536
 * @return     zero on success
537
 */
538
int avfilter_request_frame(AVFilterLink *link);
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540
/**
541
 * Polls a frame from the filter chain.
542
 * @param  link the input link
543
 * @return the number of immediately available frames, a negative
544
 * number in case of error
545
 */
546
int avfilter_poll_frame(AVFilterLink *link);
547

    
548
/**
549
 * Notifies the next filter of the start of a frame.
550
 * @param link   the output link the frame will be sent over
551
 * @param picref A reference to the frame about to be sent. The data for this
552
 *               frame need only be valid once draw_slice() is called for that
553
 *               portion. The receiving filter will free this reference when
554
 *               it no longer needs it.
555
 */
556
void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
557

    
558
/**
559
 * Notifies the next filter that the current frame has finished.
560
 * @param link the output link the frame was sent over
561
 */
562
void avfilter_end_frame(AVFilterLink *link);
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564
/**
565
 * Sends a slice to the next filter.
566
 * @param link the output link over which the frame is being sent
567
 * @param y    offset in pixels from the top of the image for this slice
568
 * @param h    height of this slice in pixels
569
 */
570
void avfilter_draw_slice(AVFilterLink *link, int y, int h);
571

    
572
/** Initializes the filter system. Registers all builtin filters. */
573
void avfilter_register_all(void);
574

    
575
/** Uninitializes the filter system. Unregisters all filters. */
576
void avfilter_uninit(void);
577

    
578
/**
579
 * Registers a filter. This is only needed if you plan to use
580
 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
581
 * filter can still by instantiated with avfilter_open even if it is not
582
 * registered.
583
 * @param filter the filter to register
584
 */
585
void avfilter_register(AVFilter *filter);
586

    
587
/**
588
 * Gets a filter definition matching the given name.
589
 * @param name the filter name to find
590
 * @return     the filter definition, if any matching one is registered.
591
 *             NULL if none found.
592
 */
593
AVFilter *avfilter_get_by_name(const char *name);
594

    
595
/**
596
 * Creates a filter instance.
597
 * @param filter    the filter to create an instance of
598
 * @param inst_name Name to give to the new instance. Can be NULL for none.
599
 * @return          Pointer to the new instance on success. NULL on failure.
600
 */
601
AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name);
602

    
603
/**
604
 * Initializes a filter.
605
 * @param filter the filter to initialize
606
 * @param args   A string of parameters to use when initializing the filter.
607
 *               The format and meaning of this string varies by filter.
608
 * @param opaque Any extra non-string data needed by the filter. The meaning
609
 *               of this parameter varies by filter.
610
 * @return       zero on success
611
 */
612
int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
613

    
614
/**
615
 * Destroys a filter.
616
 * @param filter the filter to destroy
617
 */
618
void avfilter_destroy(AVFilterContext *filter);
619

    
620
/**
621
 * Inserts a filter in the middle of an existing link.
622
 * @param link the link into which the filter should be inserted
623
 * @param filt the filter to be inserted
624
 * @param in   the input pad on the filter to connect
625
 * @param out  the output pad on the filter to connect
626
 * @return     zero on success
627
 */
628
int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
629
                           unsigned in, unsigned out);
630

    
631
/**
632
 * Inserts a new pad.
633
 * @param idx Insertion point. Pad is inserted at the end if this point
634
 *            is beyond the end of the list of pads.
635
 * @param count Pointer to the number of pads in the list
636
 * @param padidx_off Offset within an AVFilterLink structure to the element
637
 *                   to increment when inserting a new pad causes link
638
 *                   numbering to change
639
 * @param pads Pointer to the pointer to the beginning of the list of pads
640
 * @param links Pointer to the pointer to the beginning of the list of links
641
 * @param newpad The new pad to add. A copy is made when adding.
642
 */
643
void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
644
                         AVFilterPad **pads, AVFilterLink ***links,
645
                         AVFilterPad *newpad);
646

    
647
/** Inserts a new input pad for the filter. */
648
static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
649
                                         AVFilterPad *p)
650
{
651
    avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
652
                        &f->input_pads, &f->inputs, p);
653
}
654

    
655
/** Inserts a new output pad for the filter. */
656
static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
657
                                          AVFilterPad *p)
658
{
659
    avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
660
                        &f->output_pads, &f->outputs, p);
661
}
662

    
663
#endif  /* AVFILTER_AVFILTER_H */