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/*
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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 Libav.
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 *
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 * Libav 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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 * Libav 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 Libav; 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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#include "libavutil/samplefmt.h"
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#define LIBAVFILTER_VERSION_MAJOR  1
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#define LIBAVFILTER_VERSION_MINOR 76
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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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/**
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 * Return 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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 * Return 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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 * Return 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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/**
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 * A reference-counted buffer 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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 * AVFilterBufferRef structure below.
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 */
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typedef struct AVFilterBuffer {
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    uint8_t *data[8];           ///< buffer data for each plane/channel
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    int linesize[8];            ///< number of bytes per line
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    unsigned refcount;          ///< number of references to this buffer
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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 buffer 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 AVFilterBuffer *buf);
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    int format;                 ///< media format
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    int w, h;                   ///< width and height of the allocated buffer
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} AVFilterBuffer;
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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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#define AV_PERM_NEG_LINESIZES 0x20  ///< the buffer requested can have negative linesizes
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/**
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 * Audio specific properties in a reference to an AVFilterBuffer. Since
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 * AVFilterBufferRef is common to different media formats, audio specific
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 * per reference properties must be separated out.
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 */
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typedef struct AVFilterBufferRefAudioProps {
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    int64_t channel_layout;     ///< channel layout of audio buffer
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    int nb_samples;             ///< number of audio samples
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    int size;                   ///< audio buffer size
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    uint32_t sample_rate;       ///< audio buffer sample rate
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    int planar;                 ///< audio buffer - planar or packed
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} AVFilterBufferRefAudioProps;
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/**
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 * Video specific properties in a reference to an AVFilterBuffer. Since
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 * AVFilterBufferRef is common to different media formats, video specific
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 * per reference properties must be separated out.
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 */
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typedef struct AVFilterBufferRefVideoProps {
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    int w;                      ///< image width
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    int h;                      ///< image height
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    AVRational pixel_aspect;    ///< pixel aspect ratio
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    int interlaced;             ///< is frame interlaced
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    int top_field_first;        ///< field order
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} AVFilterBufferRefVideoProps;
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/**
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 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
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 * a buffer to, for example, crop image without any memcpy, the buffer 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 AVFilterBufferRef {
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    AVFilterBuffer *buf;        ///< the buffer that this is a reference to
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    uint8_t *data[8];           ///< picture/audio data for each plane
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    int linesize[8];            ///< number of bytes per line
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    int format;                 ///< media format
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    /**
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     * presentation timestamp. The time unit may change during
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     * filtering, as it is specified in the link and the filter code
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     * may need to rescale the PTS accordingly.
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     */
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    int64_t pts;
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    int64_t pos;                ///< byte position in stream, -1 if unknown
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    int perms;                  ///< permissions, see the AV_PERM_* flags
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    enum AVMediaType type;      ///< media type of buffer data
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    AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
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    AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
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} AVFilterBufferRef;
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/**
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 * Copy properties of src to dst, without copying the actual data
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 */
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static inline void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src)
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{
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    // copy common properties
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    dst->pts             = src->pts;
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    dst->pos             = src->pos;
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    switch (src->type) {
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    case AVMEDIA_TYPE_VIDEO: *dst->video = *src->video; break;
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    case AVMEDIA_TYPE_AUDIO: *dst->audio = *src->audio; break;
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    }
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}
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/**
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 * Add a new reference to a buffer.
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 *
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 * @param ref   an existing reference to the buffer
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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 buffer 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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AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
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/**
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 * Remove a reference to a buffer. If this is the last reference to the
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 * buffer, the buffer itself is also automatically freed.
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 *
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 * @param ref reference to the buffer, may be NULL
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 */
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void avfilter_unref_buffer(AVFilterBufferRef *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 {
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    unsigned format_count;      ///< number of formats
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    int *formats;               ///< list of media formats
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    unsigned refcount;          ///< number of references to this list
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    struct AVFilterFormats ***refs; ///< references to this list
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}  AVFilterFormats;
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/**
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 * Create a list of supported formats. This is intended for use in
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 * AVFilter->query_formats().
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 *
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 * @param fmts list of media formats, terminated by -1
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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 int *fmts);
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/**
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 * Add fmt to the list of media formats contained in *avff.
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 * If *avff is NULL the function allocates the filter formats struct
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 * and puts its pointer in *avff.
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 *
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 * @return a non negative value in case of success, or a negative
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 * value corresponding to an AVERROR code in case of error
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 */
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int avfilter_add_format(AVFilterFormats **avff, int fmt);
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/**
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 * Return a list of all formats supported by Libav for the given media type.
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 */
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AVFilterFormats *avfilter_all_formats(enum AVMediaType type);
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/**
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 * Return 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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 * Add *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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 * If *ref is non-NULL, remove *ref as a reference to the format list
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 * it currently points to, deallocates that list if this was the last
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 * 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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     * 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 AVMediaType 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, AVFilterBufferRef *picref);
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    /**
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     * Callback function to get a video 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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    AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h);
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    /**
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     * Callback function to get an audio buffer. If NULL, the filter system will
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     * use avfilter_default_get_audio_buffer().
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     *
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     * Input audio pads only.
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     */
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    AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms,
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                                           enum AVSampleFormat sample_fmt, int size,
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                                           int64_t channel_layout, int planar);
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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, int slice_dir);
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    /**
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     * Samples filtering callback. This is where a filter receives audio data
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     * and should do its processing.
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     *
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     * Input audio pads only.
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     */
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    void (*filter_samples)(AVFilterLink *link, AVFilterBufferRef *samplesref);
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    /**
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     * Frame poll callback. This returns the number of immediately available
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     * samples. 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
426
     * negotiated between filters by the filter system using the
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     * query_formats() callback before this function is called.
428
     *
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     * For input pads, this should check the properties of the link, and update
430
     * 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,
433
     * and another value on error.
434
     */
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    int (*config_props)(AVFilterLink *link);
436
};
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/** default handler for start_frame() for video inputs */
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void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *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, int slice_dir);
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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 filter_samples() for audio inputs */
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void avfilter_default_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
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/** default handler for config_props() for audio/video outputs */
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int avfilter_default_config_output_link(AVFilterLink *link);
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/** default handler for config_props() for audio/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 */
457
AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,
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                                                     int perms, int w, int h);
459

    
460
/** default handler for get_audio_buffer() for audio inputs */
461
AVFilterBufferRef *avfilter_default_get_audio_buffer(AVFilterLink *link, int perms,
462
                                                     enum AVSampleFormat sample_fmt, int size,
463
                                                     int64_t channel_layout, int planar);
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465
/**
466
 * A helper for query_formats() which sets all links to the same list of
467
 * formats. If there are no links hooked to this filter, the list of formats is
468
 * freed.
469
 */
470
void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);
471

    
472
/** Default handler for query_formats() */
473
int avfilter_default_query_formats(AVFilterContext *ctx);
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475
/** start_frame() handler for filters which simply pass video along */
476
void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
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/** draw_slice() handler for filters which simply pass video along */
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void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
480

    
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/** end_frame() handler for filters which simply pass video along */
482
void avfilter_null_end_frame(AVFilterLink *link);
483

    
484
/** filter_samples() handler for filters which simply pass audio along */
485
void avfilter_null_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
486

    
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/** get_video_buffer() handler for filters which simply pass video along */
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AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link,
489
                                                  int perms, int w, int h);
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491
/** get_audio_buffer() handler for filters which simply pass audio along */
492
AVFilterBufferRef *avfilter_null_get_audio_buffer(AVFilterLink *link, int perms,
493
                                                  enum AVSampleFormat sample_fmt, int size,
494
                                                  int64_t channel_layout, int planar);
495

    
496
/**
497
 * Filter definition. This defines the pads a filter contains, and all the
498
 * callback functions used to interact with the filter.
499
 */
500
typedef struct AVFilter {
501
    const char *name;         ///< filter name
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503
    int priv_size;      ///< size of private data to allocate for the filter
504

    
505
    /**
506
     * Filter initialization function. Args contains the user-supplied
507
     * parameters. FIXME: maybe an AVOption-based system would be better?
508
     * opaque is data provided by the code requesting creation of the filter,
509
     * and is used to pass data to the filter.
510
     */
511
    int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
512

    
513
    /**
514
     * Filter uninitialization function. Should deallocate any memory held
515
     * by the filter, release any buffer references, etc. This does not need
516
     * to deallocate the AVFilterContext->priv memory itself.
517
     */
518
    void (*uninit)(AVFilterContext *ctx);
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520
    /**
521
     * Queries formats supported by the filter and its pads, and sets the
522
     * in_formats for links connected to its output pads, and out_formats
523
     * for links connected to its input pads.
524
     *
525
     * @return zero on success, a negative value corresponding to an
526
     * AVERROR code otherwise
527
     */
528
    int (*query_formats)(AVFilterContext *);
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530
    const AVFilterPad *inputs;  ///< NULL terminated list of inputs. NULL if none
531
    const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
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533
    /**
534
     * A description for the filter. You should use the
535
     * NULL_IF_CONFIG_SMALL() macro to define it.
536
     */
537
    const char *description;
538
} AVFilter;
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540
/** An instance of a filter */
541
struct AVFilterContext {
542
    const AVClass *av_class;              ///< needed for av_log()
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544
    AVFilter *filter;               ///< the AVFilter of which this is an instance
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546
    char *name;                     ///< name of this filter instance
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548
    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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552
    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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556
    void *priv;                     ///< private data for use by the filter
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};
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559
/**
560
 * A link between two filters. This contains pointers to the source and
561
 * destination filters between which this link exists, and the indexes of
562
 * the pads involved. In addition, this link also contains the parameters
563
 * which have been negotiated and agreed upon between the filter, such as
564
 * image dimensions, format, etc.
565
 */
566
struct AVFilterLink {
567
    AVFilterContext *src;       ///< source filter
568
    AVFilterPad *srcpad;        ///< output pad on the source filter
569

    
570
    AVFilterContext *dst;       ///< dest filter
571
    AVFilterPad *dstpad;        ///< input pad on the dest filter
572

    
573
    /** stage of the initialization of the link properties (dimensions, etc) */
574
    enum {
575
        AVLINK_UNINIT = 0,      ///< not started
576
        AVLINK_STARTINIT,       ///< started, but incomplete
577
        AVLINK_INIT             ///< complete
578
    } init_state;
579

    
580
    enum AVMediaType type;      ///< filter media type
581

    
582
    /* These parameters apply only to video */
583
    int w;                      ///< agreed upon image width
584
    int h;                      ///< agreed upon image height
585
    AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
586
    /* These two parameters apply only to audio */
587
    int64_t channel_layout;     ///< channel layout of current buffer (see libavutil/audioconvert.h)
588
    int64_t sample_rate;        ///< samples per second
589

    
590
    int format;                 ///< agreed upon media format
591

    
592
    /**
593
     * Lists of formats supported by the input and output filters respectively.
594
     * These lists are used for negotiating the format to actually be used,
595
     * which will be loaded into the format member, above, when chosen.
596
     */
597
    AVFilterFormats *in_formats;
598
    AVFilterFormats *out_formats;
599

    
600
    /**
601
     * The buffer reference currently being sent across the link by the source
602
     * filter. This is used internally by the filter system to allow
603
     * automatic copying of buffers which do not have sufficient permissions
604
     * for the destination. This should not be accessed directly by the
605
     * filters.
606
     */
607
    AVFilterBufferRef *src_buf;
608

    
609
    AVFilterBufferRef *cur_buf;
610
    AVFilterBufferRef *out_buf;
611

    
612
    /**
613
     * Define the time base used by the PTS of the frames/samples
614
     * which will pass through this link.
615
     * During the configuration stage, each filter is supposed to
616
     * change only the output timebase, while the timebase of the
617
     * input link is assumed to be an unchangeable property.
618
     */
619
    AVRational time_base;
620
};
621

    
622
/**
623
 * Link two filters together.
624
 *
625
 * @param src    the source filter
626
 * @param srcpad index of the output pad on the source filter
627
 * @param dst    the destination filter
628
 * @param dstpad index of the input pad on the destination filter
629
 * @return       zero on success
630
 */
631
int avfilter_link(AVFilterContext *src, unsigned srcpad,
632
                  AVFilterContext *dst, unsigned dstpad);
633

    
634
/**
635
 * Negotiate the media format, dimensions, etc of all inputs to a filter.
636
 *
637
 * @param filter the filter to negotiate the properties for its inputs
638
 * @return       zero on successful negotiation
639
 */
640
int avfilter_config_links(AVFilterContext *filter);
641

    
642
/**
643
 * Request a picture buffer with a specific set of permissions.
644
 *
645
 * @param link  the output link to the filter from which the buffer will
646
 *              be requested
647
 * @param perms the required access permissions
648
 * @param w     the minimum width of the buffer to allocate
649
 * @param h     the minimum height of the buffer to allocate
650
 * @return      A reference to the buffer. This must be unreferenced with
651
 *              avfilter_unref_buffer when you are finished with it.
652
 */
653
AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms,
654
                                          int w, int h);
655

    
656
/**
657
 * Create a buffer reference wrapped around an already allocated image
658
 * buffer.
659
 *
660
 * @param data pointers to the planes of the image to reference
661
 * @param linesize linesizes for the planes of the image to reference
662
 * @param perms the required access permissions
663
 * @param w the width of the image specified by the data and linesize arrays
664
 * @param h the height of the image specified by the data and linesize arrays
665
 * @param format the pixel format of the image specified by the data and linesize arrays
666
 */
667
AVFilterBufferRef *
668
avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
669
                                          int w, int h, enum PixelFormat format);
670

    
671
/**
672
 * Request an audio samples buffer with a specific set of permissions.
673
 *
674
 * @param link           the output link to the filter from which the buffer will
675
 *                       be requested
676
 * @param perms          the required access permissions
677
 * @param sample_fmt     the format of each sample in the buffer to allocate
678
 * @param size           the buffer size in bytes
679
 * @param channel_layout the number and type of channels per sample in the buffer to allocate
680
 * @param planar         audio data layout - planar or packed
681
 * @return               A reference to the samples. This must be unreferenced with
682
 *                       avfilter_unref_buffer when you are finished with it.
683
 */
684
AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms,
685
                                             enum AVSampleFormat sample_fmt, int size,
686
                                             int64_t channel_layout, int planar);
687

    
688
/**
689
 * Request an input frame from the filter at the other end of the link.
690
 *
691
 * @param link the input link
692
 * @return     zero on success
693
 */
694
int avfilter_request_frame(AVFilterLink *link);
695

    
696
/**
697
 * Poll a frame from the filter chain.
698
 *
699
 * @param  link the input link
700
 * @return the number of immediately available frames, a negative
701
 * number in case of error
702
 */
703
int avfilter_poll_frame(AVFilterLink *link);
704

    
705
/**
706
 * Notifie the next filter of the start of a frame.
707
 *
708
 * @param link   the output link the frame will be sent over
709
 * @param picref A reference to the frame about to be sent. The data for this
710
 *               frame need only be valid once draw_slice() is called for that
711
 *               portion. The receiving filter will free this reference when
712
 *               it no longer needs it.
713
 */
714
void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref);
715

    
716
/**
717
 * Notifie the next filter that the current frame has finished.
718
 *
719
 * @param link the output link the frame was sent over
720
 */
721
void avfilter_end_frame(AVFilterLink *link);
722

    
723
/**
724
 * Send a slice to the next filter.
725
 *
726
 * Slices have to be provided in sequential order, either in
727
 * top-bottom or bottom-top order. If slices are provided in
728
 * non-sequential order the behavior of the function is undefined.
729
 *
730
 * @param link the output link over which the frame is being sent
731
 * @param y    offset in pixels from the top of the image for this slice
732
 * @param h    height of this slice in pixels
733
 * @param slice_dir the assumed direction for sending slices,
734
 *             from the top slice to the bottom slice if the value is 1,
735
 *             from the bottom slice to the top slice if the value is -1,
736
 *             for other values the behavior of the function is undefined.
737
 */
738
void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);
739

    
740
/**
741
 * Send a buffer of audio samples to the next filter.
742
 *
743
 * @param link       the output link over which the audio samples are being sent
744
 * @param samplesref a reference to the buffer of audio samples being sent. The
745
 *                   receiving filter will free this reference when it no longer
746
 *                   needs it or pass it on to the next filter.
747
 */
748
void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref);
749

    
750
/** Initialize the filter system. Register all builtin filters. */
751
void avfilter_register_all(void);
752

    
753
/** Uninitialize the filter system. Unregister all filters. */
754
void avfilter_uninit(void);
755

    
756
/**
757
 * Register a filter. This is only needed if you plan to use
758
 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
759
 * filter can still by instantiated with avfilter_open even if it is not
760
 * registered.
761
 *
762
 * @param filter the filter to register
763
 * @return 0 if the registration was succesfull, a negative value
764
 * otherwise
765
 */
766
int avfilter_register(AVFilter *filter);
767

    
768
/**
769
 * Get a filter definition matching the given name.
770
 *
771
 * @param name the filter name to find
772
 * @return     the filter definition, if any matching one is registered.
773
 *             NULL if none found.
774
 */
775
AVFilter *avfilter_get_by_name(const char *name);
776

    
777
/**
778
 * If filter is NULL, returns a pointer to the first registered filter pointer,
779
 * if filter is non-NULL, returns the next pointer after filter.
780
 * If the returned pointer points to NULL, the last registered filter
781
 * was already reached.
782
 */
783
AVFilter **av_filter_next(AVFilter **filter);
784

    
785
/**
786
 * Create a filter instance.
787
 *
788
 * @param filter_ctx put here a pointer to the created filter context
789
 * on success, NULL on failure
790
 * @param filter    the filter to create an instance of
791
 * @param inst_name Name to give to the new instance. Can be NULL for none.
792
 * @return >= 0 in case of success, a negative error code otherwise
793
 */
794
int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
795

    
796
/**
797
 * Initialize a filter.
798
 *
799
 * @param filter the filter to initialize
800
 * @param args   A string of parameters to use when initializing the filter.
801
 *               The format and meaning of this string varies by filter.
802
 * @param opaque Any extra non-string data needed by the filter. The meaning
803
 *               of this parameter varies by filter.
804
 * @return       zero on success
805
 */
806
int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
807

    
808
/**
809
 * Free a filter context.
810
 *
811
 * @param filter the filter to free
812
 */
813
void avfilter_free(AVFilterContext *filter);
814

    
815
/**
816
 * Insert a filter in the middle of an existing link.
817
 *
818
 * @param link the link into which the filter should be inserted
819
 * @param filt the filter to be inserted
820
 * @param filt_srcpad_idx the input pad on the filter to connect
821
 * @param filt_dstpad_idx the output pad on the filter to connect
822
 * @return     zero on success
823
 */
824
int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
825
                           unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
826

    
827
/**
828
 * Insert a new pad.
829
 *
830
 * @param idx Insertion point. Pad is inserted at the end if this point
831
 *            is beyond the end of the list of pads.
832
 * @param count Pointer to the number of pads in the list
833
 * @param padidx_off Offset within an AVFilterLink structure to the element
834
 *                   to increment when inserting a new pad causes link
835
 *                   numbering to change
836
 * @param pads Pointer to the pointer to the beginning of the list of pads
837
 * @param links Pointer to the pointer to the beginning of the list of links
838
 * @param newpad The new pad to add. A copy is made when adding.
839
 */
840
void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
841
                         AVFilterPad **pads, AVFilterLink ***links,
842
                         AVFilterPad *newpad);
843

    
844
/** Insert a new input pad for the filter. */
845
static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
846
                                         AVFilterPad *p)
847
{
848
    avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
849
                        &f->input_pads, &f->inputs, p);
850
}
851

    
852
/** Insert a new output pad for the filter. */
853
static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
854
                                          AVFilterPad *p)
855
{
856
    avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
857
                        &f->output_pads, &f->outputs, p);
858
}
859

    
860
#endif  /* AVFILTER_AVFILTER_H */