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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 FFMPEG_AVFILTER_H
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#define FFMPEG_AVFILTER_H
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#include "avcodec.h"
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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];
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    int linesize[4];    ///< number of bytes per line
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    enum PixelFormat format;
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    unsigned refcount;
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    void *priv;
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    void (*free)(struct AVFilterPic *pic);
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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 pts, and 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;
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    uint8_t *data[4];
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    int linesize[4];
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    int w, h;
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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
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} AVFilterPicRef;
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/**
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 * Add a new reference to a picture.
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 * @param ref An existing reference to the picture
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 * @return A new reference to the picture with the same properties as the old
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 */
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AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref);
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/**
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 * Remove 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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struct AVFilterPad
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{
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    /**
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     * Pad name.  The name is unique among inputs and among oututs, but an
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     * input may have the same name as an output.
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     */
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    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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    int type;
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#define AV_PAD_VIDEO 0
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    /**
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     * Callback to get a list of supported formats.  The returned list should
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     * be terminated by -1.  This is used for both input and output pads and
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     * is required for both.
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     */
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    int *(*query_formats)(AVFilterLink *link);
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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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    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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     * handle buffer requests.  Only required for input video pads.
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     */
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    AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms);
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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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    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.  Only required for input video pads.
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     */
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    void (*draw_slice)(AVFilterLink *link, uint8_t *data[4], int y, int height);
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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.  Video output pads only.
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     */
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    void (*request_frame)(AVFilterLink *link);
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    /**
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     * Link configuration callback.  For output pads, this should set the link
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     * properties such as width/height.  NOTE: this should not set the format
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     * property - that is negotiated between filters by the filter system using
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     * the query_formats() callback.
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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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    int (*config_props)(AVFilterLink *link);
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};
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/* the default implementations of start_frame() and end_frame() */
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void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
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void avfilter_default_end_frame(AVFilterLink *link);
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typedef struct
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{
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    char *name;
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    char *author;
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    int priv_size;
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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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     */
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    int (*init)(AVFilterContext *ctx, const char *args);
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    void (*uninit)(AVFilterContext *ctx);
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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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} AVFilter;
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struct AVFilterContext
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{
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    AVClass *av_class;
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    AVFilter *filter;
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    AVFilterLink **inputs;
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    AVFilterLink **outputs;
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    void *priv;
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};
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struct AVFilterLink
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{
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    AVFilterContext *src;
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    unsigned int srcpad;
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    AVFilterContext *dst;
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    unsigned int dstpad;
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    int w, h;
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    enum PixelFormat format;
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    AVFilterPicRef *cur_pic;
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};
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/** Link two filters together */
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int avfilter_link(AVFilterContext *src, unsigned srcpad,
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                  AVFilterContext *dst, unsigned dstpad);
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AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);
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void avfilter_request_frame(AVFilterLink *link);
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void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
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void avfilter_end_frame(AVFilterLink *link);
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void avfilter_draw_slice(AVFilterLink *link, uint8_t *data[4], int y, int h);
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void avfilter_init(void);
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void avfilter_uninit(void);
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void avfilter_register(AVFilter *filter);
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AVFilter *avfilter_get_by_name(char *name);
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AVFilterContext *avfilter_create(AVFilter *filter);
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AVFilterContext *avfilter_create_by_name(char *name);
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int avfilter_init_filter(AVFilterContext *filter, const char *args);
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void avfilter_destroy(AVFilterContext *filter);
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int *avfilter_make_format_list(int len, ...);
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#endif  /* FFMPEG_AVFILTER_H */