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
scaled_x(int val,const struct scale_factors * sf)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
scaled_y(int val,const struct scale_factors * sf)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
unscaled_value(int val,const struct scale_factors * sf)23 static int unscaled_value(int val, const struct scale_factors *sf) {
24 (void) sf;
25 return val;
26 }
27
get_fixed_point_scale_factor(int other_size,int this_size)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
check_scale_factors(int other_w,int other_h,int this_w,int this_h)36 static int check_scale_factors(int other_w, int other_h,
37 int this_w, int this_h) {
38 return 2 * this_w >= other_w &&
39 2 * this_h >= other_h &&
40 this_w <= 16 * other_w &&
41 this_h <= 16 * other_h;
42 }
43
vp9_scale_mv(const MV * mv,int x,int y,const struct scale_factors * sf)44 MV32 vp9_scale_mv(const MV *mv, int x, int y, const struct scale_factors *sf) {
45 const int x_off_q4 = scaled_x(x << SUBPEL_BITS, sf) & SUBPEL_MASK;
46 const int y_off_q4 = scaled_y(y << SUBPEL_BITS, sf) & SUBPEL_MASK;
47 const MV32 res = {
48 scaled_y(mv->row, sf) + y_off_q4,
49 scaled_x(mv->col, sf) + x_off_q4
50 };
51 return res;
52 }
53
vp9_setup_scale_factors_for_frame(struct scale_factors * sf,int other_w,int other_h,int this_w,int this_h)54 void vp9_setup_scale_factors_for_frame(struct scale_factors *sf,
55 int other_w, int other_h,
56 int this_w, int this_h) {
57 if (!check_scale_factors(other_w, other_h, this_w, this_h)) {
58 sf->x_scale_fp = REF_INVALID_SCALE;
59 sf->y_scale_fp = REF_INVALID_SCALE;
60 return;
61 }
62
63 sf->x_scale_fp = get_fixed_point_scale_factor(other_w, this_w);
64 sf->y_scale_fp = get_fixed_point_scale_factor(other_h, this_h);
65 sf->x_step_q4 = scaled_x(16, sf);
66 sf->y_step_q4 = scaled_y(16, sf);
67
68 if (vp9_is_scaled(sf)) {
69 sf->scale_value_x = scaled_x;
70 sf->scale_value_y = scaled_y;
71 } else {
72 sf->scale_value_x = unscaled_value;
73 sf->scale_value_y = unscaled_value;
74 }
75
76 // TODO(agrange): Investigate the best choice of functions to use here
77 // for EIGHTTAP_SMOOTH. Since it is not interpolating, need to choose what
78 // to do at full-pel offsets. The current selection, where the filter is
79 // applied in one direction only, and not at all for 0,0, seems to give the
80 // best quality, but it may be worth trying an additional mode that does
81 // do the filtering on full-pel.
82 if (sf->x_step_q4 == 16) {
83 if (sf->y_step_q4 == 16) {
84 // No scaling in either direction.
85 sf->predict[0][0][0] = vp9_convolve_copy;
86 sf->predict[0][0][1] = vp9_convolve_avg;
87 sf->predict[0][1][0] = vp9_convolve8_vert;
88 sf->predict[0][1][1] = vp9_convolve8_avg_vert;
89 sf->predict[1][0][0] = vp9_convolve8_horiz;
90 sf->predict[1][0][1] = vp9_convolve8_avg_horiz;
91 } else {
92 // No scaling in x direction. Must always scale in the y direction.
93 sf->predict[0][0][0] = vp9_convolve8_vert;
94 sf->predict[0][0][1] = vp9_convolve8_avg_vert;
95 sf->predict[0][1][0] = vp9_convolve8_vert;
96 sf->predict[0][1][1] = vp9_convolve8_avg_vert;
97 sf->predict[1][0][0] = vp9_convolve8;
98 sf->predict[1][0][1] = vp9_convolve8_avg;
99 }
100 } else {
101 if (sf->y_step_q4 == 16) {
102 // No scaling in the y direction. Must always scale in the x direction.
103 sf->predict[0][0][0] = vp9_convolve8_horiz;
104 sf->predict[0][0][1] = vp9_convolve8_avg_horiz;
105 sf->predict[0][1][0] = vp9_convolve8;
106 sf->predict[0][1][1] = vp9_convolve8_avg;
107 sf->predict[1][0][0] = vp9_convolve8_horiz;
108 sf->predict[1][0][1] = vp9_convolve8_avg_horiz;
109 } else {
110 // Must always scale in both directions.
111 sf->predict[0][0][0] = vp9_convolve8;
112 sf->predict[0][0][1] = vp9_convolve8_avg;
113 sf->predict[0][1][0] = vp9_convolve8;
114 sf->predict[0][1][1] = vp9_convolve8_avg;
115 sf->predict[1][0][0] = vp9_convolve8;
116 sf->predict[1][0][1] = vp9_convolve8_avg;
117 }
118 }
119 // 2D subpel motion always gets filtered in both directions
120 sf->predict[1][1][0] = vp9_convolve8;
121 sf->predict[1][1][1] = vp9_convolve8_avg;
122 }
123