src/third_party/libvpx/source/libvpx/vp9/common/vp9_scale.c

   1 /*
   2  *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license
   5  *  that can be found in the LICENSE file in the root of the source
   6  *  tree. An additional intellectual property rights grant can be found
   7  *  in the file PATENTS.  All contributing project authors may
   8  *  be found in the AUTHORS file in the root of the source tree.
   9  */
  10
  11 #include "./vp9_rtcd.h"
  12 #include "vp9/common/vp9_filter.h"
  13 #include "vp9/common/vp9_scale.h"
  14
  15 static INLINE int scaled_x(int val, const struct scale_factors *sf) {
  16   return (int)((int64_t)val * sf->x_scale_fp >> REF_SCALE_SHIFT);
  17 }
  18
  19 static INLINE int scaled_y(int val, const struct scale_factors *sf) {
  20   return (int)((int64_t)val * sf->y_scale_fp >> REF_SCALE_SHIFT);
  21 }
  22
  23 static int unscaled_value(int val, const struct scale_factors *sf) {
  24   (void) sf;
  25   return val;
  26 }
  27
  28 static int get_fixed_point_scale_factor(int other_size, int this_size) {
  29   // Calculate scaling factor once for each reference frame
  30   // and use fixed point scaling factors in decoding and encoding routines.
  31   // Hardware implementations can calculate scale factor in device driver
  32   // and use multiplication and shifting on hardware instead of division.
  33   return (other_size << REF_SCALE_SHIFT) / this_size;
  34 }
  35
  36 MV32 vp9_scale_mv(const MV *mv, int x, int y, const struct scale_factors *sf) {
  37   const int x_off_q4 = scaled_x(x << SUBPEL_BITS, sf) & SUBPEL_MASK;
  38   const int y_off_q4 = scaled_y(y << SUBPEL_BITS, sf) & SUBPEL_MASK;
  39   const MV32 res = {
  40     scaled_y(mv->row, sf) + y_off_q4,
  41     scaled_x(mv->col, sf) + x_off_q4
  42   };
  43   return res;
  44 }
  45
  46 #if CONFIG_VP9_HIGHBITDEPTH
  47 void vp9_setup_scale_factors_for_frame(struct scale_factors *sf,
  48                                        int other_w, int other_h,
  49                                        int this_w, int this_h,
  50                                        int use_high) {
  51 #else
  52 void vp9_setup_scale_factors_for_frame(struct scale_factors *sf,
  53                                        int other_w, int other_h,
  54                                        int this_w, int this_h) {
  55 #endif
  56   if (!valid_ref_frame_size(other_w, other_h, this_w, this_h)) {
  57     sf->x_scale_fp = REF_INVALID_SCALE;
  58     sf->y_scale_fp = REF_INVALID_SCALE;
  59     return;
  60   }
  61
  62   sf->x_scale_fp = get_fixed_point_scale_factor(other_w, this_w);
  63   sf->y_scale_fp = get_fixed_point_scale_factor(other_h, this_h);
  64   sf->x_step_q4 = scaled_x(16, sf);
  65   sf->y_step_q4 = scaled_y(16, sf);
  66
  67   if (vp9_is_scaled(sf)) {
  68     sf->scale_value_x = scaled_x;
  69     sf->scale_value_y = scaled_y;
  70   } else {
  71     sf->scale_value_x = unscaled_value;
  72     sf->scale_value_y = unscaled_value;
  73   }
  74
  75   // TODO(agrange): Investigate the best choice of functions to use here
  76   // for EIGHTTAP_SMOOTH. Since it is not interpolating, need to choose what
  77   // to do at full-pel offsets. The current selection, where the filter is
  78   // applied in one direction only, and not at all for 0,0, seems to give the
  79   // best quality, but it may be worth trying an additional mode that does
  80   // do the filtering on full-pel.
  81   if (sf->x_step_q4 == 16) {
  82     if (sf->y_step_q4 == 16) {
  83       // No scaling in either direction.
  84       sf->predict[0][0][0] = vp9_convolve_copy;
  85       sf->predict[0][0][1] = vp9_convolve_avg;
  86       sf->predict[0][1][0] = vp9_convolve8_vert;
  87       sf->predict[0][1][1] = vp9_convolve8_avg_vert;
  88       sf->predict[1][0][0] = vp9_convolve8_horiz;
  89       sf->predict[1][0][1] = vp9_convolve8_avg_horiz;
  90     } else {
  91       // No scaling in x direction. Must always scale in the y direction.
  92       sf->predict[0][0][0] = vp9_convolve8_vert;
  93       sf->predict[0][0][1] = vp9_convolve8_avg_vert;
  94       sf->predict[0][1][0] = vp9_convolve8_vert;
  95       sf->predict[0][1][1] = vp9_convolve8_avg_vert;
  96       sf->predict[1][0][0] = vp9_convolve8;
  97       sf->predict[1][0][1] = vp9_convolve8_avg;
  98     }
  99   } else {
 100     if (sf->y_step_q4 == 16) {
 101       // No scaling in the y direction. Must always scale in the x direction.
 102       sf->predict[0][0][0] = vp9_convolve8_horiz;
 103       sf->predict[0][0][1] = vp9_convolve8_avg_horiz;
 104       sf->predict[0][1][0] = vp9_convolve8;
 105       sf->predict[0][1][1] = vp9_convolve8_avg;
 106       sf->predict[1][0][0] = vp9_convolve8_horiz;
 107       sf->predict[1][0][1] = vp9_convolve8_avg_horiz;
 108     } else {
 109       // Must always scale in both directions.
 110       sf->predict[0][0][0] = vp9_convolve8;
 111       sf->predict[0][0][1] = vp9_convolve8_avg;
 112       sf->predict[0][1][0] = vp9_convolve8;
 113       sf->predict[0][1][1] = vp9_convolve8_avg;
 114       sf->predict[1][0][0] = vp9_convolve8;
 115       sf->predict[1][0][1] = vp9_convolve8_avg;
 116     }
 117   }
 118   // 2D subpel motion always gets filtered in both directions
 119   sf->predict[1][1][0] = vp9_convolve8;
 120   sf->predict[1][1][1] = vp9_convolve8_avg;
 121 #if CONFIG_VP9_HIGHBITDEPTH
 122   if (use_high) {
 123     if (sf->x_step_q4 == 16) {
 124       if (sf->y_step_q4 == 16) {
 125         // No scaling in either direction.
 126         sf->high_predict[0][0][0] = vp9_high_convolve_copy;
 127         sf->high_predict[0][0][1] = vp9_high_convolve_avg;
 128         sf->high_predict[0][1][0] = vp9_high_convolve8_vert;
 129         sf->high_predict[0][1][1] = vp9_high_convolve8_avg_vert;
 130         sf->high_predict[1][0][0] = vp9_high_convolve8_horiz;
 131         sf->high_predict[1][0][1] = vp9_high_convolve8_avg_horiz;
 132       } else {
 133         // No scaling in x direction. Must always scale in the y direction.
 134         sf->high_predict[0][0][0] = vp9_high_convolve8_vert;
 135         sf->high_predict[0][0][1] = vp9_high_convolve8_avg_vert;
 136         sf->high_predict[0][1][0] = vp9_high_convolve8_vert;
 137         sf->high_predict[0][1][1] = vp9_high_convolve8_avg_vert;
 138         sf->high_predict[1][0][0] = vp9_high_convolve8;
 139         sf->high_predict[1][0][1] = vp9_high_convolve8_avg;
 140       }
 141     } else {
 142       if (sf->y_step_q4 == 16) {
 143         // No scaling in the y direction. Must always scale in the x direction.
 144         sf->high_predict[0][0][0] = vp9_high_convolve8_horiz;
 145         sf->high_predict[0][0][1] = vp9_high_convolve8_avg_horiz;
 146         sf->high_predict[0][1][0] = vp9_high_convolve8;
 147         sf->high_predict[0][1][1] = vp9_high_convolve8_avg;
 148         sf->high_predict[1][0][0] = vp9_high_convolve8_horiz;
 149         sf->high_predict[1][0][1] = vp9_high_convolve8_avg_horiz;
 150       } else {
 151         // Must always scale in both directions.
 152         sf->high_predict[0][0][0] = vp9_high_convolve8;
 153         sf->high_predict[0][0][1] = vp9_high_convolve8_avg;
 154         sf->high_predict[0][1][0] = vp9_high_convolve8;
 155         sf->high_predict[0][1][1] = vp9_high_convolve8_avg;
 156         sf->high_predict[1][0][0] = vp9_high_convolve8;
 157         sf->high_predict[1][0][1] = vp9_high_convolve8_avg;
 158       }
 159     }
 160     // 2D subpel motion always gets filtered in both directions.
 161     sf->high_predict[1][1][0] = vp9_high_convolve8;
 162     sf->high_predict[1][1][1] = vp9_high_convolve8_avg;
 163   }
 164 #endif
 165 }