third_party/libdav1d/src/ipred_prepare.h

/*
 * Copyright © 2018, VideoLAN and dav1d authors
 * Copyright © 2018, Two Orioles, LLC
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef DAV1D_SRC_IPRED_PREPARE_H
#define DAV1D_SRC_IPRED_PREPARE_H

#include <stddef.h>
#include <stdint.h>

#include "common/bitdepth.h"

#include "src/env.h"
#include "src/intra_edge.h"
#include "src/levels.h"

/*
 * Luma intra edge preparation.
 *
 * x/y/start/w/h are in luma block (4px) units:
 * - x and y are the absolute block positions in the image;
 * - start/w/h are the *dependent tile* boundary positions. In practice, start
 *   is the horizontal tile start, w is the horizontal tile end, the vertical
 *   tile start is assumed to be 0 and h is the vertical image end.
 *
 * edge_flags signals which edges are available for this transform-block inside
 * the given partition, as well as for the partition inside the superblock
 * structure.
 *
 * dst and stride are pointers to the top/left position of the current block,
 * and can be used to locate the top, left, top/left, top/right and bottom/left
 * edge pointers also.
 *
 * angle is the angle_delta [-3..3] on input, and the absolute angle on output.
 *
 * mode is the intra prediction mode as coded in the bitstream. The return value
 * is this same mode, converted to an index in the DSP functions.
 *
 * tw/th are the size of the transform block in block (4px) units.
 *
 * topleft_out is a pointer to scratch memory that will be filled with the edge
 * pixels. The memory array should have space to be indexed in the [-2*w,2*w]
 * range, in the following order:
 * - [0] will be the top/left edge pixel;
 * - [1..w] will be the top edge pixels (1 being left-most, w being right-most);
 * - [w+1..2*w] will be the top/right edge pixels;
 * - [-1..-w] will be the left edge pixels (-1 being top-most, -w being bottom-
 *   most);
 * - [-w-1..-2*w] will be the bottom/left edge pixels.
 * Each edge may remain uninitialized if it is not used by the returned mode
 * index. If edges are not available (because the edge position is outside the
 * tile dimensions or because edge_flags indicates lack of edge availability),
 * they will be extended from nearby edges as defined by the av1 spec.
 */
enum IntraPredMode
    bytefn(dav1d_prepare_intra_edges)(int x, int have_left, int y, int have_top,
                                      int w, int h, enum EdgeFlags edge_flags,
                                      const pixel *dst, ptrdiff_t stride,
                                      const pixel *prefilter_toplevel_sb_edge,
                                      enum IntraPredMode mode, int *angle,
                                      int tw, int th, int filter_edge,
                                      pixel *topleft_out HIGHBD_DECL_SUFFIX);

// These flags are OR'd with the angle argument into intra predictors.
// ANGLE_USE_EDGE_FILTER_FLAG signals that edges should be convolved
// with a filter before using them to predict values in a block.
// ANGLE_SMOOTH_EDGE_FLAG means that edges are smooth and should use
// reduced filter strength.
#define ANGLE_USE_EDGE_FILTER_FLAG 1024
#define ANGLE_SMOOTH_EDGE_FLAG      512

static inline int sm_flag(const BlockContext *const b, const int idx) {
    if (!b->intra[idx]) return 0;
    const enum IntraPredMode m = b->mode[idx];
    return (m == SMOOTH_PRED || m == SMOOTH_H_PRED ||
            m == SMOOTH_V_PRED) ? ANGLE_SMOOTH_EDGE_FLAG : 0;
}

static inline int sm_uv_flag(const BlockContext *const b, const int idx) {
    const enum IntraPredMode m = b->uvmode[idx];
    return (m == SMOOTH_PRED || m == SMOOTH_H_PRED ||
            m == SMOOTH_V_PRED) ? ANGLE_SMOOTH_EDGE_FLAG : 0;
}

#endif /* DAV1D_SRC_IPRED_PREPARE_H */