/*
 *
 * 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.
 */
#include <arm_neon.h>
#include <assert.h>

#include "av1/common/resize.h"
#include "config/av1_rtcd.h"
#include "config/aom_scale_rtcd.h"

static INLINE void scale_plane_2_to_1_phase_0(const uint8_t *src,
                                              const int src_stride,
                                              uint8_t *dst,
                                              const int dst_stride, const int w,
                                              const int h) {
  const int max_width = (w + 15) & ~15;
  int y = h;

  assert(w && h);

  do {
    int x = max_width;
    do {
      const uint8x16x2_t s = vld2q_u8(src);
      vst1q_u8(dst, s.val[0]);
      src += 32;
      dst += 16;
      x -= 16;
    } while (x);
    src += 2 * (src_stride - max_width);
    dst += dst_stride - max_width;
  } while (--y);
}

static INLINE void scale_plane_bilinear_kernel(
    const uint8x16_t in0, const uint8x16_t in1, const uint8x16_t in2,
    const uint8x16_t in3, const uint8x8_t coef0, const uint8x8_t coef1,
    uint8_t *const dst) {
  const uint16x8_t h0 = vmull_u8(vget_low_u8(in0), coef0);
  const uint16x8_t h1 = vmull_u8(vget_high_u8(in0), coef0);
  const uint16x8_t h2 = vmull_u8(vget_low_u8(in2), coef0);
  const uint16x8_t h3 = vmull_u8(vget_high_u8(in2), coef0);
  const uint16x8_t h4 = vmlal_u8(h0, vget_low_u8(in1), coef1);
  const uint16x8_t h5 = vmlal_u8(h1, vget_high_u8(in1), coef1);
  const uint16x8_t h6 = vmlal_u8(h2, vget_low_u8(in3), coef1);
  const uint16x8_t h7 = vmlal_u8(h3, vget_high_u8(in3), coef1);

  const uint8x8_t hor0 = vrshrn_n_u16(h4, 7);  // temp: 00 01 02 03 04 05 06 07
  const uint8x8_t hor1 = vrshrn_n_u16(h5, 7);  // temp: 08 09 0A 0B 0C 0D 0E 0F
  const uint8x8_t hor2 = vrshrn_n_u16(h6, 7);  // temp: 10 11 12 13 14 15 16 17
  const uint8x8_t hor3 = vrshrn_n_u16(h7, 7);  // temp: 18 19 1A 1B 1C 1D 1E 1F
  const uint16x8_t v0 = vmull_u8(hor0, coef0);
  const uint16x8_t v1 = vmull_u8(hor1, coef0);
  const uint16x8_t v2 = vmlal_u8(v0, hor2, coef1);
  const uint16x8_t v3 = vmlal_u8(v1, hor3, coef1);
  // dst: 0 1 2 3 4 5 6 7  8 9 A B C D E F
  const uint8x16_t d = vcombine_u8(vrshrn_n_u16(v2, 7), vrshrn_n_u16(v3, 7));
  vst1q_u8(dst, d);
}

static INLINE void scale_plane_2_to_1_bilinear(
    const uint8_t *const src, const int src_stride, uint8_t *dst,
    const int dst_stride, const int w, const int h, const int16_t c0,
    const int16_t c1) {
  const int max_width = (w + 15) & ~15;
  const uint8_t *src0 = src;
  const uint8_t *src1 = src + src_stride;
  const uint8x8_t coef0 = vdup_n_u8(c0);
  const uint8x8_t coef1 = vdup_n_u8(c1);
  int y = h;

  assert(w && h);

  do {
    int x = max_width;
    do {
      // 000 002 004 006 008 00A 00C 00E  010 012 014 016 018 01A 01C 01E
      // 001 003 005 007 009 00B 00D 00F  011 013 015 017 019 01B 01D 01F
      const uint8x16x2_t s0 = vld2q_u8(src0);
      // 100 102 104 106 108 10A 10C 10E  110 112 114 116 118 11A 11C 11E
      // 101 103 105 107 109 10B 10D 10F  111 113 115 117 119 11B 11D 11F
      const uint8x16x2_t s1 = vld2q_u8(src1);
      scale_plane_bilinear_kernel(s0.val[0], s0.val[1], s1.val[0], s1.val[1],
                                  coef0, coef1, dst);
      src0 += 32;
      src1 += 32;
      dst += 16;
      x -= 16;
    } while (x);
    src0 += 2 * (src_stride - max_width);
    src1 += 2 * (src_stride - max_width);
    dst += dst_stride - max_width;
  } while (--y);
}

void av1_resize_and_extend_frame_neon(const YV12_BUFFER_CONFIG *src,
                                      YV12_BUFFER_CONFIG *dst,
                                      const InterpFilter filter,
                                      const int phase, const int num_planes) {
  // We use AOMMIN(num_planes, MAX_MB_PLANE) instead of num_planes to quiet
  // the static analysis warnings.
  for (int i = 0; i < AOMMIN(num_planes, MAX_MB_PLANE); ++i) {
    const int is_uv = i > 0;
    const int src_w = src->crop_widths[is_uv];
    const int src_h = src->crop_heights[is_uv];
    const int dst_w = dst->crop_widths[is_uv];
    const int dst_h = dst->crop_heights[is_uv];

    if (2 * dst_w == src_w && 2 * dst_h == src_h) {
      if (phase == 0) {
        scale_plane_2_to_1_phase_0(src->buffers[i], src->strides[is_uv],
                                   dst->buffers[i], dst->strides[is_uv], dst_w,
                                   dst_h);
      } else if (filter == BILINEAR) {
        const int16_t c0 = av1_bilinear_filters[phase][3];
        const int16_t c1 = av1_bilinear_filters[phase][4];
        scale_plane_2_to_1_bilinear(src->buffers[i], src->strides[is_uv],
                                    dst->buffers[i], dst->strides[is_uv], dst_w,
                                    dst_h, c0, c1);
      } else {
        av1_resize_plane(src->buffers[i], src_h, src_w, src->strides[is_uv],
                         dst->buffers[i], dst_h, dst_w, dst->strides[is_uv]);
      }
    } else {
      av1_resize_plane(src->buffers[i], src_h, src_w, src->strides[is_uv],
                       dst->buffers[i], dst_h, dst_w, dst->strides[is_uv]);
    }
  }
  aom_extend_frame_borders(dst, num_planes);
}