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bd2837387c
The assumption depends on the corresponding assumption done by sws_scale() and by the scale filter. Originally committed as revision 20655 to svn://svn.ffmpeg.org/ffmpeg/trunk
674 lines
25 KiB
C
674 lines
25 KiB
C
/*
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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 AVFILTER_AVFILTER_H
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#define AVFILTER_AVFILTER_H
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#include "libavutil/avutil.h"
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#define LIBAVFILTER_VERSION_MAJOR 1
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#define LIBAVFILTER_VERSION_MINOR 11
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#define LIBAVFILTER_VERSION_MICRO 0
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#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
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LIBAVFILTER_VERSION_MINOR, \
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LIBAVFILTER_VERSION_MICRO)
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#define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
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LIBAVFILTER_VERSION_MINOR, \
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LIBAVFILTER_VERSION_MICRO)
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#define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
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#include <stddef.h>
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#include "libavcodec/avcodec.h"
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/**
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* Returns the LIBAVFILTER_VERSION_INT constant.
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*/
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unsigned avfilter_version(void);
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/**
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* Returns the libavfilter build-time configuration.
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*/
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const char * avfilter_configuration(void);
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/**
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* Returns the libavfilter license.
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*/
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const char * avfilter_license(void);
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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]; ///< 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
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unsigned refcount; ///< number of references to this image
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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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int w, h; ///< width and height of the allocated buffer
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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 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; ///< 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 units of 1/AV_TIME_BASE
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AVRational pixel_aspect; ///< pixel aspect ratio
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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, with the same contents each time
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#define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
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} AVFilterPicRef;
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/**
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* Adds 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
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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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* Removes 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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/**
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* A list of supported formats for one end of a filter link. This is used
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* during the format negotiation process to try to pick the best format to
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* use to minimize the number of necessary conversions. Each filter gives a
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* list of the formats supported by each input and output pad. The list
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* given for each pad need not be distinct - they may be references to the
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* same list of formats, as is often the case when a filter supports multiple
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* formats, but will always output the same format as it is given in input.
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*
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* In this way, a list of possible input formats and a list of possible
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* output formats are associated with each link. When a set of formats is
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* negotiated over a link, the input and output lists are merged to form a
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* new list containing only the common elements of each list. In the case
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* that there were no common elements, a format conversion is necessary.
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* Otherwise, the lists are merged, and all other links which reference
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* either of the format lists involved in the merge are also affected.
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*
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* For example, consider the filter chain:
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* filter (a) --> (b) filter (b) --> (c) filter
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*
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* where the letters in parenthesis indicate a list of formats supported on
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* the input or output of the link. Suppose the lists are as follows:
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* (a) = {A, B}
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* (b) = {A, B, C}
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* (c) = {B, C}
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*
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* First, the first link's lists are merged, yielding:
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* filter (a) --> (a) filter (a) --> (c) filter
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*
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* Notice that format list (b) now refers to the same list as filter list (a).
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* Next, the lists for the second link are merged, yielding:
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* filter (a) --> (a) filter (a) --> (a) filter
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*
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* where (a) = {B}.
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*
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* Unfortunately, when the format lists at the two ends of a link are merged,
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* we must ensure that all links which reference either pre-merge format list
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* get updated as well. Therefore, we have the format list structure store a
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* pointer to each of the pointers to itself.
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*/
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typedef struct AVFilterFormats AVFilterFormats;
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struct AVFilterFormats
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{
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unsigned format_count; ///< number of formats
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enum PixelFormat *formats; ///< list of pixel formats
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unsigned refcount; ///< number of references to this list
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AVFilterFormats ***refs; ///< references to this list
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};
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/**
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* Creates a list of supported formats. This is intended for use in
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* AVFilter->query_formats().
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* @param pix_fmt list of pixel formats, terminated by PIX_FMT_NONE
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* @return the format list, with no existing references
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*/
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AVFilterFormats *avfilter_make_format_list(const enum PixelFormat *pix_fmts);
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/**
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* Returns a list of all colorspaces supported by FFmpeg.
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*/
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AVFilterFormats *avfilter_all_colorspaces(void);
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/**
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* Returns a format list which contains the intersection of the formats of
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* a and b. Also, all the references of a, all the references of b, and
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* a and b themselves will be deallocated.
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*
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* If a and b do not share any common formats, neither is modified, and NULL
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* is returned.
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*/
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AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b);
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/**
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* Adds *ref as a new reference to formats.
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* That is the pointers will point like in the ascii art below:
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* ________
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* |formats |<--------.
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* | ____ | ____|___________________
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* | |refs| | | __|_
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* | |* * | | | | | | AVFilterLink
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* | |* *--------->|*ref|
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* | |____| | | |____|
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* |________| |________________________
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*/
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void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref);
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/**
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* Removes *ref as a reference to the format list it currently points to,
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* deallocates that list if this was the last reference, and sets *ref to NULL.
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*
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* Before After
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* ________ ________ NULL
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* |formats |<--------. |formats | ^
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* | ____ | ____|________________ | ____ | ____|________________
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* | |refs| | | __|_ | |refs| | | __|_
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* | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink
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* | |* *--------->|*ref| | |* | | | |*ref|
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* | |____| | | |____| | |____| | | |____|
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* |________| |_____________________ |________| |_____________________
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*/
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void avfilter_formats_unref(AVFilterFormats **ref);
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/**
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*
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* Before After
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* ________ ________
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* |formats |<---------. |formats |<---------.
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* | ____ | ___|___ | ____ | ___|___
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* | |refs| | | | | | |refs| | | | | NULL
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* | |* *--------->|*oldref| | |* *--------->|*newref| ^
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* | |* * | | |_______| | |* * | | |_______| ___|___
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* | |____| | | |____| | | | |
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* |________| |________| |*oldref|
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* |_______|
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*/
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void avfilter_formats_changeref(AVFilterFormats **oldref,
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AVFilterFormats **newref);
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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 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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const 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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enum CodecType type;
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/**
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* Minimum required permissions on incoming buffers. Any buffer with
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* insufficient permissions will be automatically copied by the filter
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* system to a new buffer which provides the needed access permissions.
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*
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* Input pads only.
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*/
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int min_perms;
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/**
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* Permissions which are not accepted on incoming buffers. Any buffer
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* which has any of these permissions set will be automatically copied
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* by the filter system to a new buffer which does not have those
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* permissions. This can be used to easily disallow buffers with
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* AV_PERM_REUSE.
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*
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* Input pads only.
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*/
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int rej_perms;
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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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* use avfilter_default_get_video_buffer().
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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, int w, int h);
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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.
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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, int y, int height);
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/**
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* Frame poll callback. This returns the number of immediately available
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* frames. It should return a positive value if the next request_frame()
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* is guaranteed to return one frame (with no delay).
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*
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* Defaults to just calling the source poll_frame() method.
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*
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* Output video pads only.
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*/
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int (*poll_frame)(AVFilterLink *link);
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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. 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.
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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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/** 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 draw_slice() for video inputs */
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void avfilter_default_draw_slice(AVFilterLink *link, int y, int h);
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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 get_video_buffer() for video inputs */
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AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
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int perms, int w, int h);
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/**
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* A helper for query_formats() which sets all links to the same list of
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* formats. If there are no links hooked to this filter, the list of formats is
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* freed.
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*/
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void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
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/** Default handler for query_formats() */
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int avfilter_default_query_formats(AVFilterContext *ctx);
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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 AVFilter
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{
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const char *name; ///< filter name
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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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* parameters. FIXME: maybe an AVOption-based system would be better?
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* opaque is data provided by the code requesting creation of the filter,
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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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/**
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* Query formats supported by the filter and its pads. Should set the
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* in_formats for links connected to its output pads, and out_formats
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* for links connected to its input pads.
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*
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* Should return zero on success.
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*/
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int (*query_formats)(AVFilterContext *);
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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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/**
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* A description for the filter. You should use the
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* NULL_IF_CONFIG_SMALL() macro to define it.
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*/
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const char *description;
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} AVFilter;
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/** An instance of a filter */
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struct AVFilterContext
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{
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const AVClass *av_class; ///< needed for av_log()
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AVFilter *filter; ///< the AVFilter of which this is an instance
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char *name; ///< name of this filter instance
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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; ///< 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; ///< private data for use by the filter
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};
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/**
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* A link between two filters. This contains pointers to the source and
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* destination filters between which this link exists, and the indexes 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; ///< source filter
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unsigned int srcpad; ///< index of the output pad on the source filter
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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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/** stage of the initialization of the link properties (dimensions, etc) */
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enum {
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AVLINK_UNINIT = 0, ///< not started
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AVLINK_STARTINIT, ///< started, but incomplete
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AVLINK_INIT ///< complete
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} init_state;
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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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/**
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* Lists of formats supported by the input and output filters respectively.
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* These lists are used for negotiating the format to actually be used,
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* which will be loaded into the format member, above, when chosen.
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*/
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AVFilterFormats *in_formats;
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AVFilterFormats *out_formats;
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/**
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* The picture reference currently being sent across the link by the source
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* filter. This is used internally by the filter system to allow
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* automatic copying of pictures which do not have sufficient permissions
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* for the destination. This should not be accessed directly by the
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* filters.
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*/
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AVFilterPicRef *srcpic;
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AVFilterPicRef *cur_pic;
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AVFilterPicRef *outpic;
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};
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/**
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* Links 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
|
|
* @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.
|
|
*
|
|
* Slices have to be provided in sequential order, either in
|
|
* top-bottom or bottom-top order. If slices are provided in
|
|
* non-sequential order the behavior of the function is undefined.
|
|
*
|
|
* @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 */
|