/*

 *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.

 *

 *  Use of this source code is governed by a BSD-style license

 *  that can be found in the LICENSE file in the root of the source

 *  tree. An additional intellectual property rights grant can be found

 *  in the file PATENTS.  All contributing project authors may

 *  be found in the AUTHORS file in the root of the source tree.

 */

#include "./vpx_dsp_rtcd.h"

#include "vp9/common/vp9_filter.h"

#include "vp9/common/vp9_scale.h"

#include "vpx_dsp/vpx_filter.h"

static INLINE int scaled_x(int val, const struct scale_factors *sf) {

  return (int)((int64_t)val * sf->x_scale_fp >> REF_SCALE_SHIFT);

}

static INLINE int scaled_y(int val, const struct scale_factors *sf) {

  return (int)((int64_t)val * sf->y_scale_fp >> REF_SCALE_SHIFT);

}

static int unscaled_value(int val, const struct scale_factors *sf) {

  (void)sf;

  return val;

}

static int get_fixed_point_scale_factor(int other_size, int this_size) {

  // Calculate scaling factor once for each reference frame

  // and use fixed point scaling factors in decoding and encoding routines.

  // Hardware implementations can calculate scale factor in device driver

  // and use multiplication and shifting on hardware instead of division.

  return (other_size << REF_SCALE_SHIFT) / this_size;

}

MV32 vp9_scale_mv(const MV *mv, int x, int y, const struct scale_factors *sf) {

  const int x_off_q4 = scaled_x(x << SUBPEL_BITS, sf) & SUBPEL_MASK;

  const int y_off_q4 = scaled_y(y << SUBPEL_BITS, sf) & SUBPEL_MASK;

  const MV32 res = { scaled_y(mv->row, sf) + y_off_q4,

                     scaled_x(mv->col, sf) + x_off_q4 };

  return res;

}

#if CONFIG_VP9_HIGHBITDEPTH

void vp9_setup_scale_factors_for_frame(struct scale_factors *sf, int other_w,

                                       int other_h, int this_w, int this_h,

                                       int use_highbd) {

#else

void vp9_setup_scale_factors_for_frame(struct scale_factors *sf, int other_w,

                                       int other_h, int this_w, int this_h) {

#endif

  if (!valid_ref_frame_size(other_w, other_h, this_w, this_h)) {

    sf->x_scale_fp = REF_INVALID_SCALE;

    sf->y_scale_fp = REF_INVALID_SCALE;

    return;

  }

  sf->x_scale_fp = get_fixed_point_scale_factor(other_w, this_w);

  sf->y_scale_fp = get_fixed_point_scale_factor(other_h, this_h);

  sf->x_step_q4 = scaled_x(16, sf);

  sf->y_step_q4 = scaled_y(16, sf);

  if (vp9_is_scaled(sf)) {

    sf->scale_value_x = scaled_x;

    sf->scale_value_y = scaled_y;

  } else {

    sf->scale_value_x = unscaled_value;

    sf->scale_value_y = unscaled_value;

  }

  // TODO(agrange): Investigate the best choice of functions to use here

  // for EIGHTTAP_SMOOTH. Since it is not interpolating, need to choose what

  // to do at full-pel offsets. The current selection, where the filter is

  // applied in one direction only, and not at all for 0,0, seems to give the

  // best quality, but it may be worth trying an additional mode that does

  // do the filtering on full-pel.

  if (sf->x_step_q4 == 16) {

    if (sf->y_step_q4 == 16) {

      // No scaling in either direction.

      sf->predict[0][0][0] = vpx_convolve_copy;

      sf->predict[0][0][1] = vpx_convolve_avg;

      sf->predict[0][1][0] = vpx_convolve8_vert;

      sf->predict[0][1][1] = vpx_convolve8_avg_vert;

      sf->predict[1][0][0] = vpx_convolve8_horiz;

      sf->predict[1][0][1] = vpx_convolve8_avg_horiz;

    } else {

      // No scaling in x direction. Must always scale in the y direction.

      sf->predict[0][0][0] = vpx_scaled_vert;

      sf->predict[0][0][1] = vpx_scaled_avg_vert;

      sf->predict[0][1][0] = vpx_scaled_vert;

      sf->predict[0][1][1] = vpx_scaled_avg_vert;

      sf->predict[1][0][0] = vpx_scaled_2d;

      sf->predict[1][0][1] = vpx_scaled_avg_2d;

    }

  } else {

    if (sf->y_step_q4 == 16) {

      // No scaling in the y direction. Must always scale in the x direction.

      sf->predict[0][0][0] = vpx_scaled_horiz;

      sf->predict[0][0][1] = vpx_scaled_avg_horiz;

      sf->predict[0][1][0] = vpx_scaled_2d;

      sf->predict[0][1][1] = vpx_scaled_avg_2d;

      sf->predict[1][0][0] = vpx_scaled_horiz;

      sf->predict[1][0][1] = vpx_scaled_avg_horiz;

    } else {

      // Must always scale in both directions.

      sf->predict[0][0][0] = vpx_scaled_2d;

      sf->predict[0][0][1] = vpx_scaled_avg_2d;

      sf->predict[0][1][0] = vpx_scaled_2d;

      sf->predict[0][1][1] = vpx_scaled_avg_2d;

      sf->predict[1][0][0] = vpx_scaled_2d;

      sf->predict[1][0][1] = vpx_scaled_avg_2d;

    }

  }

  // 2D subpel motion always gets filtered in both directions

  if ((sf->x_step_q4 != 16) || (sf->y_step_q4 != 16)) {

    sf->predict[1][1][0] = vpx_scaled_2d;

    sf->predict[1][1][1] = vpx_scaled_avg_2d;

  } else {

    sf->predict[1][1][0] = vpx_convolve8;

    sf->predict[1][1][1] = vpx_convolve8_avg;

  }

#if CONFIG_VP9_HIGHBITDEPTH

  if (use_highbd) {

    if (sf->x_step_q4 == 16) {

      if (sf->y_step_q4 == 16) {

        // No scaling in either direction.

        sf->highbd_predict[0][0][0] = vpx_highbd_convolve_copy;

        sf->highbd_predict[0][0][1] = vpx_highbd_convolve_avg;

        sf->highbd_predict[0][1][0] = vpx_highbd_convolve8_vert;

        sf->highbd_predict[0][1][1] = vpx_highbd_convolve8_avg_vert;

        sf->highbd_predict[1][0][0] = vpx_highbd_convolve8_horiz;

        sf->highbd_predict[1][0][1] = vpx_highbd_convolve8_avg_horiz;

      } else {

        // No scaling in x direction. Must always scale in the y direction.

        sf->highbd_predict[0][0][0] = vpx_highbd_convolve8_vert;

        sf->highbd_predict[0][0][1] = vpx_highbd_convolve8_avg_vert;

        sf->highbd_predict[0][1][0] = vpx_highbd_convolve8_vert;

        sf->highbd_predict[0][1][1] = vpx_highbd_convolve8_avg_vert;

        sf->highbd_predict[1][0][0] = vpx_highbd_convolve8;

        sf->highbd_predict[1][0][1] = vpx_highbd_convolve8_avg;

      }

    } else {

      if (sf->y_step_q4 == 16) {

        // No scaling in the y direction. Must always scale in the x direction.

        sf->highbd_predict[0][0][0] = vpx_highbd_convolve8_horiz;

        sf->highbd_predict[0][0][1] = vpx_highbd_convolve8_avg_horiz;

        sf->highbd_predict[0][1][0] = vpx_highbd_convolve8;

        sf->highbd_predict[0][1][1] = vpx_highbd_convolve8_avg;

        sf->highbd_predict[1][0][0] = vpx_highbd_convolve8_horiz;

        sf->highbd_predict[1][0][1] = vpx_highbd_convolve8_avg_horiz;

      } else {

        // Must always scale in both directions.

        sf->highbd_predict[0][0][0] = vpx_highbd_convolve8;

        sf->highbd_predict[0][0][1] = vpx_highbd_convolve8_avg;

        sf->highbd_predict[0][1][0] = vpx_highbd_convolve8;

        sf->highbd_predict[0][1][1] = vpx_highbd_convolve8_avg;

        sf->highbd_predict[1][0][0] = vpx_highbd_convolve8;

        sf->highbd_predict[1][0][1] = vpx_highbd_convolve8_avg;

      }

    }

    // 2D subpel motion always gets filtered in both directions.

    sf->highbd_predict[1][1][0] = vpx_highbd_convolve8;

    sf->highbd_predict[1][1][1] = vpx_highbd_convolve8_avg;

  }

#endif

}