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/*
* Filter layer
* copyright (c) 2007 Bobby Bingham
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef FFMPEG_AVFILTER_H
#define FFMPEG_AVFILTER_H
#include "avcodec.h"
typedef struct AVFilterContext AVFilterContext;
typedef struct AVFilterLink AVFilterLink;
typedef struct AVFilterPad AVFilterPad;
/* TODO: look for other flags which may be useful in this structure (interlace
* flags, etc)
*/
/**
* A reference-counted picture data type used by the filter system. Filters
* should not store pointers to this structure directly, but instead use the
* AVFilterPicRef structure below
*/
typedef struct AVFilterPic
{
uint8_t *data[4];
int linesize[4]; ///< number of bytes per line
enum PixelFormat format;
unsigned refcount;
void *priv;
void (*free)(struct AVFilterPic *pic);
} AVFilterPic;
/**
* A reference to an AVFilterPic. Since filters can manipulate the origin of
* a picture to, for example, crop image without any memcpy, the picture origin
* and dimensions are per-reference properties. Linesize is also useful for
* image flipping, frame to field filters, etc, and so is also per-reference.
*
* TODO: add anything necessary for frame reordering
*/
typedef struct AVFilterPicRef
{
AVFilterPic *pic;
uint8_t *data[4];
int linesize[4];
int w, h;
int64_t pts; ///< presentation timestamp in milliseconds
int perms; ///< permissions
#define AV_PERM_READ 0x01 ///< can read from the buffer
#define AV_PERM_WRITE 0x02 ///< can write to the buffer
#define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times
} AVFilterPicRef;
/**
* Add a new reference to a picture.
* @param ref An existing reference to the picture
* @param pmask A bitmask containing the allowable permissions in the new reference
* @return A new reference to the picture with the same properties as the old
*/
AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
/**
* Remove a reference to a picture. If this is the last reference to the
* picture, the picture itself is also automatically freed.
* @param ref Reference to the picture.
*/
void avfilter_unref_pic(AVFilterPicRef *ref);
struct AVFilterPad
{
/**
* Pad name. The name is unique among inputs and among oututs, but an
* input may have the same name as an output.
*/
char *name;
/**
* AVFilterPad type. Only video supported now, hopefully someone will
* add audio in the future.
*/
int type;
#define AV_PAD_VIDEO 0
/**
* Callback to get a list of supported formats. The returned list should
* be terminated by -1. This is used for both input and output pads and
* is required for both.
*/
int *(*query_formats)(AVFilterLink *link);
/**
* Callback called before passing the first slice of a new frame. If
* NULL, the filter layer will default to storing a reference to the
* picture inside the link structure.
*/
void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
/**
* Callback function to get a buffer. If NULL, the filter system will
* handle buffer requests. Only required for input video pads.
*/
AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms);
/**
* Callback called after the slices of a frame are completely sent. If
* NULL, the filter layer will default to releasing the reference stored
* in the link structure during start_frame().
*/
void (*end_frame)(AVFilterLink *link);
/**
* Slice drawing callback. This is where a filter receives video data
* and should do its processing. Only required for input video pads.
*/
void (*draw_slice)(AVFilterLink *link, uint8_t *data[4], int y, int height);
/**
* Frame request callback. A call to this should result in at least one
* frame being output over the given link. Video output pads only.
*/
void (*request_frame)(AVFilterLink *link);
/**
* Link configuration callback. For output pads, this should set the link
* properties such as width/height. NOTE: this should not set the format
* property - that is negotiated between filters by the filter system using
* the query_formats() callback.
*
* For input pads, this should check the properties of the link, and update
* the filter's internal state as necessary.
*/
int (*config_props)(AVFilterLink *link);
};
/* the default implementations of start_frame() and end_frame() */
void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
void avfilter_default_end_frame(AVFilterLink *link);
typedef struct
{
char *name;
char *author;
int priv_size;
/**
* Filter initialization function. Args contains the user-supplied
* parameters. FIXME: maybe an AVOption-based system would be better?
* opaque is data provided by the code requesting creation of the filter,
* and is used to pass data to the filter.
*/
int (*init)(AVFilterContext *ctx, const char *args, const void *opaque);
void (*uninit)(AVFilterContext *ctx);
const AVFilterPad *inputs; /// NULL terminated list of inputs. NULL if none
const AVFilterPad *outputs; /// NULL terminated list of outputs. NULL if none
} AVFilter;
struct AVFilterContext
{
AVClass *av_class;
AVFilter *filter;
char *name;
AVFilterLink **inputs;
AVFilterLink **outputs;
void *priv;
};
struct AVFilterLink
{
AVFilterContext *src;
unsigned int srcpad;
AVFilterContext *dst;
unsigned int dstpad;
int w, h;
enum PixelFormat format;
AVFilterPicRef *cur_pic;
AVFilterPicRef *outpic;
};
/** Link two filters together */
int avfilter_link(AVFilterContext *src, unsigned srcpad,
AVFilterContext *dst, unsigned dstpad);
AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);
void avfilter_request_frame(AVFilterLink *link);
void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
void avfilter_end_frame(AVFilterLink *link);
void avfilter_draw_slice(AVFilterLink *link, uint8_t *data[4], int y, int h);
void avfilter_init(void);
void avfilter_uninit(void);
void avfilter_register(AVFilter *filter);
AVFilter *avfilter_get_by_name(char *name);
AVFilterContext *avfilter_create(AVFilter *filter, char *inst_name);
AVFilterContext *avfilter_create_by_name(char *name, char *inst_name);
int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
void avfilter_destroy(AVFilterContext *filter);
int *avfilter_make_format_list(int len, ...);
#endif /* FFMPEG_AVFILTER_H */
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