ffmpeg/libavfilter/avfilter.h
Vitor Sessak 72f6d6317c Remove the data parameter from draw_slice(). It's unneeded and often more
work than it's worth.

Commited in SoC by Bobby Bingham on 2007-08-17 14:39:11

Originally committed as revision 12096 to svn://svn.ffmpeg.org/ffmpeg/trunk
2008-02-15 22:13:44 +00:00

436 lines
16 KiB
C

/*
* 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 <stddef.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]; ///< picture data for each plane
int linesize[4]; ///< number of bytes per line
enum PixelFormat format; ///< colorspace
unsigned refcount; ///< number of references to this image
/** private data to be used by a custom free function */
void *priv;
/**
* A pointer to the function to deallocate this image if the default
* function is not sufficient. This could, for example, add the memory
* back into a memory pool to be reused later without the overhead of
* reallocating it from scratch.
*/
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; ///< the picture that this is a reference to
uint8_t *data[4]; ///< picture data for each plane
int linesize[4]; ///< number of bytes per line
int w; ///< image width
int h; ///< image height
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, excluding any permissions denied by pmask
*/
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);
/**
* A filter pad used for either input or output
*/
struct AVFilterPad
{
/**
* Pad name. The name is unique among inputs and among outputs, but an
* input may have the same name as an output. This may be NULL if this
* pad has no need to ever be referenced by name.
*/
char *name;
/**
* AVFilterPad type. Only video supported now, hopefully someone will
* add audio in the future.
*/
int type;
#define AV_PAD_VIDEO 0 ///< video pad
/**
* Callback to get a list of supported formats. The returned list should
* be terminated by -1 (see avfilter_make_format_list for an easy way to
* create such a list).
*
* This is used for both input and output pads. If ommitted from an output
* pad, it is assumed that the only format supported is the same format
* that is being used for the filter's first input. If the filter has no
* inputs, then this may not be ommitted for its output pads.
*/
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.
*
* Input video pads only.
*/
void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
/**
* Callback function to get a buffer. If NULL, the filter system will
* handle buffer requests.
*
* Input video pads only.
*/
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().
*
* Input video pads only.
*/
void (*end_frame)(AVFilterLink *link);
/**
* Slice drawing callback. This is where a filter receives video data
* and should do its processing.
*
* Input video pads only.
*/
void (*draw_slice)(AVFilterLink *link, int y, int height);
/**
* Frame request callback. A call to this should result in at least one
* frame being output over the given link. This should return zero on
* success, and another value on error.
*
* Output video pads only.
*/
int (*request_frame)(AVFilterLink *link);
/**
* Link configuration callback.
*
* For output pads, this should set the link properties such as
* width/height. This should NOT set the format property - that is
* negotiated between filters by the filter system using the
* query_formats() callback before this function is called.
*
* For input pads, this should check the properties of the link, and update
* the filter's internal state as necessary.
*
* For both input and output filters, this should return zero on success,
* and another value on error.
*/
int (*config_props)(AVFilterLink *link);
};
/** Default handler for start_frame() for video inputs */
void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
/** Default handler for end_frame() for video inputs */
void avfilter_default_end_frame(AVFilterLink *link);
/** Default handler for config_props() for video outputs */
int avfilter_default_config_output_link(AVFilterLink *link);
/** Default handler for config_props() for video inputs */
int avfilter_default_config_input_link (AVFilterLink *link);
/** Default handler for query_formats() for video outputs */
int *avfilter_default_query_output_formats(AVFilterLink *link);
/** Default handler for get_video_buffer() for video inputs */
AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
int perms);
/**
* Filter definition. This defines the pads a filter contains, and all the
* callback functions used to interact with the filter.
*/
typedef struct
{
char *name; ///< filter name
char *author; ///< filter author
int priv_size; ///< size of private data to allocate for the filter
/**
* 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, void *opaque);
/**
* Filter uninitialization function. Should deallocate any memory held
* by the filter, release any picture references, etc. This does not need
* to deallocate the AVFilterContext->priv memory itself.
*/
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;
/** An instance of a filter */
struct AVFilterContext
{
AVClass *av_class; ///< Needed for av_log()
AVFilter *filter; ///< The AVFilter of which this is an instance
char *name; ///< name of this filter instance
unsigned input_count; ///< number of input pads
AVFilterPad *input_pads; ///< array of input pads
AVFilterLink **inputs; ///< array of pointers to input links
unsigned output_count; ///< number of output pads
AVFilterPad *output_pads; ///< array of output pads
AVFilterLink **outputs; ///< array of pointers to output links
void *priv; ///< private data for use by the filter
};
/**
* A links between two filters. This contains pointers to the source and
* destination filters between which this link exists, and the indices of
* the pads involved. In addition, this link also contains the parameters
* which have been negotiated and agreed upon between the filter, such as
* image dimensions, format, etc
*/
struct AVFilterLink
{
AVFilterContext *src; ///< source filter
unsigned int srcpad; ///< index of the output pad on the source filter
AVFilterContext *dst; ///< dest filter
unsigned int dstpad; ///< index of the input pad on the dest filter
int w; ///< agreed upon image width
int h; ///< agreed upon image height
enum PixelFormat format; ///< agreed upon image colorspace
AVFilterPicRef *cur_pic;
AVFilterPicRef *outpic;
};
/**
* Link two filters together
* @param src The source filter
* @param srcpad Index of the output pad on the source filter
* @param dst The destination filter
* @param dstpad Index of the input pad on the destination filter
* @return Zero on success
*/
int avfilter_link(AVFilterContext *src, unsigned srcpad,
AVFilterContext *dst, unsigned dstpad);
/**
* Negotiate the colorspace, dimensions, etc of a link
* @param link The link to negotiate the properties of
* @return Zero on successful negotiation
*/
int avfilter_config_link(AVFilterLink *link);
/**
* Request a picture buffer with a specific set of permissions
* @param link The output link to the filter from which the picture will
* be requested
* @param perms The required access permissions
* @return A reference to the picture. This must be unreferenced with
* avfilter_unref_pic when you are finished with it.
*/
AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);
/**
* Request an input frame from the filter at the other end of the link.
* @param link The input link
* @return Zero on success
*/
int avfilter_request_frame(AVFilterLink *link);
/**
* Notofy the next filter of the start of a frame.
* @param link The output link the frame will be sent over
* @param picref A reference to the frame about to be sent. The data for this
* frame need only be valid once draw_slice() is called for that
* portion. The receiving filter will free this reference when
* it no longer needs it.
*/
void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
/**
* Notify the next filter that the current frame has finished
* @param link The output link the frame was sent over
*/
void avfilter_end_frame(AVFilterLink *link);
/**
* Send a slice to the next filter
* @param link The output link over which the frame is being sent
* @param y Offset in pixels from the top of the image for this slice
* @param h Height of this slice in pixels
*/
void avfilter_draw_slice(AVFilterLink *link, int y, int h);
/** Initialize the filter system. Registers all builtin filters */
void avfilter_init(void);
/** Uninitialize the filter system. Unregisters all filters */
void avfilter_uninit(void);
/**
* Register a filter. This is only needed if you plan to create an instance of
* this filter by name later with avfilter_create_by_name. A filter can still
* by created with acfilter_create even if it is not registered.
* @param filter The filter to register
*/
void avfilter_register(AVFilter *filter);
/**
* Gets a filter definition matching the given name
* @param name The filter name to find
* @return The filter definition, if any matching one is registered.
* NULL if none found.
*/
AVFilter *avfilter_get_by_name(char *name);
/**
* Create a filter instance
* @param filter The filter to create an instance of
* @param inst_name Name to give to the new instance. Can be NULL for none.
* @return Pointer to the new instance on success. NULL on failure.
*/
AVFilterContext *avfilter_create(AVFilter *filter, char *inst_name);
/**
* Creates a filter instace
* @param name The name of the filter type which is to be instantiated
* @param inst_name Name to give to the new instance. Can be NULL for none.
* @return Pointer to the new instance on success. NULL in failure.
*/
AVFilterContext *avfilter_create_by_name(char *name, char *inst_name);
/**
* Initialize a filter
* @param filter The filter to initialize
* @param args A string of parameters to use when initializing the filter.
* The format and meaning of this string varies by filter.
* @param opaque Any extra non-string data needed by the filter. The meaning
* of this parameter varies by filter.
* @return Zero on success
*/
int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
/**
* Destroy a filter
* @param filter The filter to destroy
*/
void avfilter_destroy(AVFilterContext *filter);
/**
* Helper function to create a list of supported formats. This is intended
* for use in AVFilterPad->query_formats().
* @param len The number of formats supported
* @param ... A list of the supported formats
* @return The format list in a form suitable for returning from
* AVFilterPad->query_formats()
*/
int *avfilter_make_format_list(int len, ...);
/**
* Insert a new pad
* @param idx Insertion point. Pad is inserted at the end if this point
* is beyond the end of the list of pads.
* @param count Pointer to the number of pads in the list
* @param padidx_off Offset within an AVFilterLink structure to the element
* to increment when inserting a new pad causes link
* numbering to change
* @param pads Pointer to the pointer to the beginning of the list of pads
* @param links Pointer to the pointer to the beginning of the list of links
* @param newpad The new pad to add. A copy is made when adding.
*/
void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
AVFilterPad **pads, AVFilterLink ***links,
AVFilterPad *newpad);
/** insert a new input pad for the filter */
static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
AVFilterPad *p)
{
avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
&f->input_pads, &f->inputs, p);
}
/** insert a new output pad for the filter */
static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
AVFilterPad *p)
{
avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
&f->output_pads, &f->outputs, p);
}
#endif /* FFMPEG_AVFILTER_H */