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