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FFmpeg/libavfilter/avfilter.h
Stefano Sabatini 4cc3f6afe4 Remove AVFilter.next field, since it is not used and it is not going
to be used since the implementation of the new filter registration
system.

Originally committed as revision 20611 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-11-25 23:24:09 +00:00

669 lines
25 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 AVFILTER_AVFILTER_H
#define AVFILTER_AVFILTER_H
#include "libavutil/avutil.h"
#define LIBAVFILTER_VERSION_MAJOR 1
#define LIBAVFILTER_VERSION_MINOR 11
#define LIBAVFILTER_VERSION_MICRO 0
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \
LIBAVFILTER_VERSION_MICRO)
#define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \
LIBAVFILTER_VERSION_MICRO)
#define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
#include <stddef.h>
#include "libavcodec/avcodec.h"
/**
* Returns the LIBAVFILTER_VERSION_INT constant.
*/
unsigned avfilter_version(void);
/**
* Returns the libavfilter build-time configuration.
*/
const char * avfilter_configuration(void);
/**
* Returns the libavfilter license.
*/
const char * avfilter_license(void);
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);
int w, h; ///< width and height of the allocated buffer
} 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 units of 1/AV_TIME_BASE
AVRational pixel_aspect; ///< pixel aspect ratio
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, with the same contents each time
#define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
} AVFilterPicRef;
/**
* Adds 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);
/**
* Removes 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 list of supported formats for one end of a filter link. This is used
* during the format negotiation process to try to pick the best format to
* use to minimize the number of necessary conversions. Each filter gives a
* list of the formats supported by each input and output pad. The list
* given for each pad need not be distinct - they may be references to the
* same list of formats, as is often the case when a filter supports multiple
* formats, but will always output the same format as it is given in input.
*
* In this way, a list of possible input formats and a list of possible
* output formats are associated with each link. When a set of formats is
* negotiated over a link, the input and output lists are merged to form a
* new list containing only the common elements of each list. In the case
* that there were no common elements, a format conversion is necessary.
* Otherwise, the lists are merged, and all other links which reference
* either of the format lists involved in the merge are also affected.
*
* For example, consider the filter chain:
* filter (a) --> (b) filter (b) --> (c) filter
*
* where the letters in parenthesis indicate a list of formats supported on
* the input or output of the link. Suppose the lists are as follows:
* (a) = {A, B}
* (b) = {A, B, C}
* (c) = {B, C}
*
* First, the first link's lists are merged, yielding:
* filter (a) --> (a) filter (a) --> (c) filter
*
* Notice that format list (b) now refers to the same list as filter list (a).
* Next, the lists for the second link are merged, yielding:
* filter (a) --> (a) filter (a) --> (a) filter
*
* where (a) = {B}.
*
* Unfortunately, when the format lists at the two ends of a link are merged,
* we must ensure that all links which reference either pre-merge format list
* get updated as well. Therefore, we have the format list structure store a
* pointer to each of the pointers to itself.
*/
typedef struct AVFilterFormats AVFilterFormats;
struct AVFilterFormats
{
unsigned format_count; ///< number of formats
enum PixelFormat *formats; ///< list of pixel formats
unsigned refcount; ///< number of references to this list
AVFilterFormats ***refs; ///< references to this list
};
/**
* Creates a list of supported formats. This is intended for use in
* AVFilter->query_formats().
* @param pix_fmt list of pixel formats, terminated by PIX_FMT_NONE
* @return the format list, with no existing references
*/
AVFilterFormats *avfilter_make_format_list(const enum PixelFormat *pix_fmts);
/**
* Returns a list of all colorspaces supported by FFmpeg.
*/
AVFilterFormats *avfilter_all_colorspaces(void);
/**
* Returns a format list which contains the intersection of the formats of
* a and b. Also, all the references of a, all the references of b, and
* a and b themselves will be deallocated.
*
* If a and b do not share any common formats, neither is modified, and NULL
* is returned.
*/
AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
/**
* Adds *ref as a new reference to formats.
* That is the pointers will point like in the ascii art below:
* ________
* |formats |<--------.
* | ____ | ____|___________________
* | |refs| | | __|_
* | |* * | | | | | | AVFilterLink
* | |* *--------->|*ref|
* | |____| | | |____|
* |________| |________________________
*/
void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
/**
* Removes *ref as a reference to the format list it currently points to,
* deallocates that list if this was the last reference, and sets *ref to NULL.
*
* Before After
* ________ ________ NULL
* |formats |<--------. |formats | ^
* | ____ | ____|________________ | ____ | ____|________________
* | |refs| | | __|_ | |refs| | | __|_
* | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
* | |* *--------->|*ref| | |* | | | |*ref|
* | |____| | | |____| | |____| | | |____|
* |________| |_____________________ |________| |_____________________
*/
void avfilter_formats_unref(AVFilterFormats **ref);
/**
*
* Before After
* ________ ________
* |formats |<---------. |formats |<---------.
* | ____ | ___|___ | ____ | ___|___
* | |refs| | | | | | |refs| | | | | NULL
* | |* *--------->|*oldref| | |* *--------->|*newref| ^
* | |* * | | |_______| | |* * | | |_______| ___|___
* | |____| | | |____| | | | |
* |________| |________| |*oldref|
* |_______|
*/
void avfilter_formats_changeref(AVFilterFormats **oldref,
AVFilterFormats **newref);
/**
* 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.
*/
const char *name;
/**
* AVFilterPad type. Only video supported now, hopefully someone will
* add audio in the future.
*/
enum CodecType type;
/**
* Minimum required permissions on incoming buffers. Any buffer with
* insufficient permissions will be automatically copied by the filter
* system to a new buffer which provides the needed access permissions.
*
* Input pads only.
*/
int min_perms;
/**
* Permissions which are not accepted on incoming buffers. Any buffer
* which has any of these permissions set will be automatically copied
* by the filter system to a new buffer which does not have those
* permissions. This can be used to easily disallow buffers with
* AV_PERM_REUSE.
*
* Input pads only.
*/
int rej_perms;
/**
* 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
* use avfilter_default_get_video_buffer().
*
* Input video pads only.
*/
AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
/**
* 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 poll callback. This returns the number of immediately available
* frames. It should return a positive value if the next request_frame()
* is guaranteed to return one frame (with no delay).
*
* Defaults to just calling the source poll_frame() method.
*
* Output video pads only.
*/
int (*poll_frame)(AVFilterLink *link);
/**
* 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 draw_slice() for video inputs */
void avfilter_default_draw_slice(AVFilterLink *link, int y, int h);
/** 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 get_video_buffer() for video inputs */
AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
int perms, int w, int h);
/**
* A helper for query_formats() which sets all links to the same list of
* formats. If there are no links hooked to this filter, the list of formats is
* freed.
*/
void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
/** Default handler for query_formats() */
int avfilter_default_query_formats(AVFilterContext *ctx);
/**
* Filter definition. This defines the pads a filter contains, and all the
* callback functions used to interact with the filter.
*/
typedef struct AVFilter
{
const char *name; ///< filter name
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);
/**
* Query formats supported by the filter and its pads. Should set the
* in_formats for links connected to its output pads, and out_formats
* for links connected to its input pads.
*
* Should return zero on success.
*/
int (*query_formats)(AVFilterContext *);
const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
/**
* A description for the filter. You should use the
* NULL_IF_CONFIG_SMALL() macro to define it.
*/
const char *description;
} AVFilter;
/** An instance of a filter */
struct AVFilterContext
{
const 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 link between two filters. This contains pointers to the source and
* destination filters between which this link exists, and the indexes 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
/** stage of the initialization of the link properties (dimensions, etc) */
enum {
AVLINK_UNINIT = 0, ///< not started
AVLINK_STARTINIT, ///< started, but incomplete
AVLINK_INIT ///< complete
} init_state;
int w; ///< agreed upon image width
int h; ///< agreed upon image height
enum PixelFormat format; ///< agreed upon image colorspace
/**
* Lists of formats supported by the input and output filters respectively.
* These lists are used for negotiating the format to actually be used,
* which will be loaded into the format member, above, when chosen.
*/
AVFilterFormats *in_formats;
AVFilterFormats *out_formats;
/**
* The picture reference currently being sent across the link by the source
* filter. This is used internally by the filter system to allow
* automatic copying of pictures which do not have sufficient permissions
* for the destination. This should not be accessed directly by the
* filters.
*/
AVFilterPicRef *srcpic;
AVFilterPicRef *cur_pic;
AVFilterPicRef *outpic;
};
/**
* Links 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);
/**
* Negotiates the colorspace, dimensions, etc of all inputs to a filter.
* @param filter the filter to negotiate the properties for its inputs
* @return zero on successful negotiation
*/
int avfilter_config_links(AVFilterContext *filter);
/**
* Requests 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
* @param w the minimum width of the buffer to allocate
* @param h the minimum height of the buffer to allocate
* @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,
int w, int h);
/**
* Requests 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);
/**
* Polls a frame from the filter chain.
* @param link the input link
* @return the number of immediately available frames, a negative
* number in case of error
*/
int avfilter_poll_frame(AVFilterLink *link);
/**
* Notifies 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);
/**
* Notifies 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);
/**
* Sends 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);
/** Initializes the filter system. Registers all builtin filters. */
void avfilter_register_all(void);
/** Uninitializes the filter system. Unregisters all filters. */
void avfilter_uninit(void);
/**
* Registers a filter. This is only needed if you plan to use
* avfilter_get_by_name later to lookup the AVFilter structure by name. A
* filter can still by instantiated with avfilter_open even if it is not
* registered.
* @param filter the filter to register
* @return 0 if the registration was succesfull, a negative value
* otherwise
*/
int 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(const char *name);
/**
* If filter is NULL, returns a pointer to the first registered filter pointer,
* if filter is non-NULL, returns the next pointer after filter.
* If the returned pointer points to NULL, the last registered filter
* was already reached.
*/
AVFilter **av_filter_next(AVFilter **filter);
/**
* Creates 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_open(AVFilter *filter, const char *inst_name);
/**
* Initializes 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);
/**
* Destroys a filter.
* @param filter the filter to destroy
*/
void avfilter_destroy(AVFilterContext *filter);
/**
* Inserts a filter in the middle of an existing link.
* @param link the link into which the filter should be inserted
* @param filt the filter to be inserted
* @param in the input pad on the filter to connect
* @param out the output pad on the filter to connect
* @return zero on success
*/
int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
unsigned in, unsigned out);
/**
* Inserts 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);
/** Inserts 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);
}
/** Inserts 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 /* AVFILTER_AVFILTER_H */