libav1/dx/shaders/inter_ext_borders.hlsl

/*
 * Copyright 2020 Google LLC
 *
 */

/*
 * Copyright (c) 2020, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 2 Clause License and
 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
 * was not distributed with this source code in the LICENSE file, you can
 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
 * Media Patent License 1.0 was not distributed with this source code in the
 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
 */

cbuffer ExtBorderSRT : register(b0) {
  uint4 cb_planes[3];
  uint4 cb_dims[2];
};

RWByteAddressBuffer Dst : register(u0);

[numthreads(64, 1, 1)] void main(uint3 thread
                                 : SV_DispatchThreadID) {
  const uint yh = cb_dims[0].y;
  const uint uvh = cb_dims[1].y;

  if (thread.x >= (yh + 2 * uvh)) return;

  const uint plane = (thread.x >= yh) + (thread.x >= (yh + uvh));
  const uint wi = thread.x - yh * (thread.x >= yh) - uvh * (thread.x >= (yh + uvh));

  const uint left_ptr = cb_planes[plane].y + wi * cb_planes[plane].x;
  const uint right_ptr = left_ptr + ((cb_dims[plane > 0].x - 1) & (~3));
  const uint shft = ((cb_dims[plane > 0].x - 1) & 3) * 8;
  uint left = (Dst.Load(left_ptr) & 0xff) * 0x01010101;
  uint right0 = Dst.Load(right_ptr);
  uint right = ((right0 >> shft) & 0xff) * 0x01010101;

  uint r0mask = (1 << shft) - 1;
  right0 = (right0 & r0mask) | (right & (~r0mask));

  Dst.Store(left_ptr - 12, left);
  Dst.Store(left_ptr - 8, left);
  Dst.Store(left_ptr - 4, left);

  Dst.Store(right_ptr + 0, right0);
  Dst.Store(right_ptr + 4, right);
  Dst.Store(right_ptr + 8, right);
  Dst.Store(right_ptr + 12, right);
}