vp9_reconinter.c

/*
 *  Copyright (c) 2010 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 <assert.h>

#include "./vpx_config.h"
#include "vpx/vpx_integer.h"
#include "vp9/common/vp9_blockd.h"
#include "vp9/common/vp9_filter.h"
#include "vp9/common/vp9_reconinter.h"
#include "vp9/common/vp9_reconintra.h"

void vp9_setup_scale_factors_for_frame(struct scale_factors *scale,
                                       YV12_BUFFER_CONFIG *other,
                                       int this_w, int this_h) {
  int other_h = other->y_crop_height;
  int other_w = other->y_crop_width;

  scale->x_num = other_w;
  scale->x_den = this_w;
  scale->x_offset_q4 = 0;  // calculated per-mb
  scale->x_step_q4 = 16 * other_w / this_w;

  scale->y_num = other_h;
  scale->y_den = this_h;
  scale->y_offset_q4 = 0;  // calculated per-mb
  scale->y_step_q4 = 16 * other_h / this_h;

  if (scale->x_num == scale->x_den && scale->y_num == scale->y_den) {
    scale->scale_value_x = unscaled_value;
    scale->scale_value_y = unscaled_value;
    scale->set_scaled_offsets = set_offsets_without_scaling;
    scale->scale_motion_vector_q3_to_q4 =
        motion_vector_q3_to_q4_without_scaling;
    scale->scale_motion_vector_component_q4 =
        motion_vector_component_q4_without_scaling;
  } else {
    scale->scale_value_x = scale_value_x_with_scaling;
    scale->scale_value_y = scale_value_y_with_scaling;
    scale->set_scaled_offsets = set_offsets_with_scaling;
    scale->scale_motion_vector_q3_to_q4 =
        motion_vector_q3_to_q4_with_scaling;
    scale->scale_motion_vector_component_q4 =
        motion_vector_component_q4_with_scaling;
  }

  // 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 (scale->x_step_q4 == 16) {
    if (scale->y_step_q4 == 16) {
      // No scaling in either direction.
      scale->predict[0][0][0] = vp9_convolve_copy;
      scale->predict[0][0][1] = vp9_convolve_avg;
      scale->predict[0][1][0] = vp9_convolve8_vert;
      scale->predict[0][1][1] = vp9_convolve8_avg_vert;
      scale->predict[1][0][0] = vp9_convolve8_horiz;
      scale->predict[1][0][1] = vp9_convolve8_avg_horiz;
    } else {
      // No scaling in x direction. Must always scale in the y direction.