Revision 13ff8fd0 libavfilter/avfilter.h

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libavfilter/avfilter.h
39 39
 */
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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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    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
45 45

  
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    unsigned refcount;
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    unsigned refcount;          ///< number of references to this image
47

  
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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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} AVFilterPic;
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......
58 66
 */
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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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    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 milliseconds
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......
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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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 * @param pmask A bitmask containing the allowable permissions in the new reference
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 * @return A new reference to the picture with the same properties as the old
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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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 */
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void avfilter_unref_pic(AVFilterPicRef *ref);
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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 oututs, but an
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     * input may have the same name as an output.
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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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    char *name;
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......
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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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#define AV_PAD_VIDEO 0      ///< video pad
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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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     * be terminated by -1 (see avfilter_make_format_list for an easy way to
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     * create such a list).
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     *
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     * This is used for both input and output pads.  If ommitted from an output
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     * pad, it is assumed that the only format supported is the same format
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     * that is being used for the filter's first input.  If the filter has no
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     * inputs, then this may not be ommitted for its output pads.
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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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     * 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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     * handle buffer requests.  Only required for input video pads.
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     * handle buffer requests.
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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);
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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.  Only required for input video pads.
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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, 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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     * 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.  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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     * 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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/* the default implementations of filter entry points */
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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 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 query_formats() for video outputs */
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int *avfilter_default_query_output_formats(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);
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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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 */
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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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    char *name;         ///< filter name
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    char *author;       ///< filter author
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    int priv_size;
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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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     * 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
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     * by the filter, release any picture references, etc.  This does not need
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     * to deallocate the AVFilterContext->priv memory itself.
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     */
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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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    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;
184 235

  
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/** An instance of a filter */
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struct AVFilterContext
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{
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    AVClass *av_class;
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    AVClass *av_class;              ///< Needed for av_log()
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    AVFilter *filter;
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    AVFilter *filter;               ///< The AVFilter of which this is an instance
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    char *name;
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    char *name;                     ///< name of this filter instance
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    unsigned input_count;
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    AVFilterPad   *input_pads;
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    AVFilterLink **inputs;
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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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    unsigned output_count;
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    AVFilterPad   *output_pads;
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    AVFilterLink **outputs;
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    unsigned output_count;          ///< number of output pads
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    AVFilterPad   *output_pads;     ///< array of output pads
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    AVFilterLink **outputs;         ///< array of pointers to output links
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    void *priv;
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    void *priv;                     ///< private data for use by the filter
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};
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/**
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 * A links between two filters.  This contains pointers to the source and
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 * destination filters between which this link exists, and the indices of
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 * the pads involved.  In addition, this link also contains the parameters
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 * which have been negotiated and agreed upon between the filter, such as
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 * image dimensions, format, etc
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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 *src;       ///< source filter
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    unsigned int srcpad;        ///< index of the output pad on the source filter
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    AVFilterContext *dst;
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    unsigned int dstpad;
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    AVFilterContext *dst;       ///< dest filter
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    unsigned int dstpad;        ///< index of the input pad on the dest filter
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    int w, h;
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    enum PixelFormat format;
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    int w;                      ///< agreed upon image width
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    int h;                      ///< agreed upon image height
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    enum PixelFormat format;    ///< agreed upon image colorspace
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    AVFilterPicRef *cur_pic;
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    AVFilterPicRef *outpic;
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};
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/** Link two filters together */
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/**
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 * Link two filters together
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 * @param src    The source filter
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 * @param srcpad Index of the output pad on the source filter
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 * @param dst    The destination filter
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 * @param dstpad Index of the input pad on the destination filter
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 * @return       Zero on success
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 */
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int avfilter_link(AVFilterContext *src, unsigned srcpad,
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                  AVFilterContext *dst, unsigned dstpad);
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/** Configure the colorspace, dimensions, etc of a link */
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/**
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 * Negotiate the colorspace, dimensions, etc of a link
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 * @param link The link to negotiate the properties of
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 * @return     Zero on successful negotiation
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 */
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int avfilter_config_link(AVFilterLink *link);
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/**
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 * Request a picture buffer with a specific set of permissions
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 * @param link  The output link to the filter from which the picture will
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 *              be requested
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 * @param perms The required access permissions
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 * @return      A reference to the picture.  This must be unreferenced with
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 *              avfilter_unref_pic when you are finished with it.
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 */
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AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);
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/**
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 * Request an input frame from the filter at the other end of the link.
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 * @param link The input link
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 * @return     Zero on success
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 */
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int  avfilter_request_frame(AVFilterLink *link);
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/**
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 * Notofy the next filter of the start of a frame.
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 * @param link   The output link the frame will be sent over
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 * @param picref A reference to the frame about to be sent.  The data for this
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 *               frame need only be valid once draw_slice() is called for that
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 *               portion.  The receiving filter will free this reference when
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 *               it no longer needs it.
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 */
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void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
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/**
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 * Notify the next filter that the current frame has finished
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 * @param link The output link the frame was sent over
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 */
229 328
void avfilter_end_frame(AVFilterLink *link);
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/**
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 * Send a slice to the next filter
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 * @param link The output link over which the frame is being sent
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 * @param data Start of the picture data for this slice
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 * @param y    Offset in pixels from the top of the image for this slice
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 * @param h    Height of this slice in pixels
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 */
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void avfilter_draw_slice(AVFilterLink *link, uint8_t *data[4], int y, int h);
231 338

  
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/** Initialize the filter system.  Registers all builtin filters */
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void avfilter_init(void);
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/** Uninitialize the filter system.  Unregisters all filters */
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void avfilter_uninit(void);
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/**
346
 * Register a filter.  This is only needed if you plan to create an instance of
347
 * this filter by name later with avfilter_create_by_name.  A filter can still
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 * by created with acfilter_create even if it is not registered.
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 * @param filter The filter to register
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 */
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void avfilter_register(AVFilter *filter);
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/**
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 * Gets a filter definition matching the given name
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 * @param name The filter name to find
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 * @return     The filter definition, if any matching one is registered.
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 *             NULL if none found.
358
 */
235 359
AVFilter *avfilter_get_by_name(char *name);
236 360

  
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/**
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 * Create a filter instance
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 * @param filter    The filter to create an instance of
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 * @param inst_name Name to give to the new instance.  Can be NULL for none.
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 * @return          Pointer to the new instance on success.  NULL on failure.
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 */
237 367
AVFilterContext *avfilter_create(AVFilter *filter, char *inst_name);
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/**
370
 * Creates a filter instace
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 * @param name      The name of the filter type which is to be instantiated
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 * @param inst_name Name to give to the new instance.  Can be NULL for none.
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 * @return          Pointer to the new instance on success.  NULL in failure.
374
 */
238 375
AVFilterContext *avfilter_create_by_name(char *name, char *inst_name);
376

  
377
/**
378
 * Initialize a filter
379
 * @param filter The filter to initialize
380
 * @param args   A string of parameters to use when initializing the filter.
381
 *               The format and meaning of this string varies by filter.
382
 * @param opaque Any extra non-string data needed by the filter.  The meaning
383
 *               of this parameter varies by filter.
384
 * @return       Zero on success
385
 */
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int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
387

  
388
/**
389
 * Destroy a filter
390
 * @param filter The filter to destroy
391
 */
240 392
void avfilter_destroy(AVFilterContext *filter);
241 393

  
394
/**
395
 * Helper function to create a list of supported formats.  This is intended
396
 * for use in AVFilterPad->query_formats().
397
 * @param len The number of formats supported
398
 * @param ... A list of the supported formats
399
 * @return    The format list in a form suitable for returning from
400
 *            AVFilterPad->query_formats()
401
 */
242 402
int *avfilter_make_format_list(int len, ...);
243 403

  
244 404
/**

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