/src/aom/av1/common/scale.c
Line | Count | Source |
1 | | /* |
2 | | * Copyright (c) 2016, Alliance for Open Media. All rights reserved. |
3 | | * |
4 | | * This source code is subject to the terms of the BSD 2 Clause License and |
5 | | * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License |
6 | | * was not distributed with this source code in the LICENSE file, you can |
7 | | * obtain it at www.aomedia.org/license/software. If the Alliance for Open |
8 | | * Media Patent License 1.0 was not distributed with this source code in the |
9 | | * PATENTS file, you can obtain it at www.aomedia.org/license/patent. |
10 | | */ |
11 | | |
12 | | #include "config/aom_dsp_rtcd.h" |
13 | | #include "config/av1_rtcd.h" |
14 | | |
15 | | #include "av1/common/filter.h" |
16 | | #include "av1/common/scale.h" |
17 | | #include "aom_dsp/aom_filter.h" |
18 | | |
19 | 756k | static int get_fixed_point_scale_factor(int other_size, int this_size) { |
20 | | // Calculate scaling factor once for each reference frame |
21 | | // and use fixed point scaling factors in decoding and encoding routines. |
22 | | // Hardware implementations can calculate scale factor in device driver |
23 | | // and use multiplication and shifting on hardware instead of division. |
24 | 756k | return ((other_size << REF_SCALE_SHIFT) + this_size / 2) / this_size; |
25 | 756k | } |
26 | | |
27 | | // Given the fixed point scale, calculate coarse point scale. |
28 | 756k | static int fixed_point_scale_to_coarse_point_scale(int scale_fp) { |
29 | 756k | return ROUND_POWER_OF_TWO(scale_fp, REF_SCALE_SHIFT - SCALE_SUBPEL_BITS); |
30 | 756k | } |
31 | | |
32 | | // Note: x and y are integer precision, mvq4 is q4 precision. |
33 | | MV32 av1_scale_mv(const MV *mvq4, int x, int y, |
34 | 2.31M | const struct scale_factors *sf) { |
35 | 2.31M | const int x_off_q4 = av1_scaled_x(x << SUBPEL_BITS, sf); |
36 | 2.31M | const int y_off_q4 = av1_scaled_y(y << SUBPEL_BITS, sf); |
37 | 2.31M | const MV32 res = { |
38 | 2.31M | av1_scaled_y((y << SUBPEL_BITS) + mvq4->row, sf) - y_off_q4, |
39 | 2.31M | av1_scaled_x((x << SUBPEL_BITS) + mvq4->col, sf) - x_off_q4 |
40 | 2.31M | }; |
41 | 2.31M | return res; |
42 | 2.31M | } |
43 | | |
44 | | void av1_setup_scale_factors_for_frame(struct scale_factors *sf, int other_w, |
45 | 385k | int other_h, int this_w, int this_h) { |
46 | 385k | if (!valid_ref_frame_size(other_w, other_h, this_w, this_h)) { |
47 | 6.81k | sf->x_scale_fp = REF_INVALID_SCALE; |
48 | 6.81k | sf->y_scale_fp = REF_INVALID_SCALE; |
49 | 6.81k | return; |
50 | 6.81k | } |
51 | | |
52 | 378k | sf->x_scale_fp = get_fixed_point_scale_factor(other_w, this_w); |
53 | 378k | sf->y_scale_fp = get_fixed_point_scale_factor(other_h, this_h); |
54 | | |
55 | 378k | sf->x_step_q4 = fixed_point_scale_to_coarse_point_scale(sf->x_scale_fp); |
56 | 378k | sf->y_step_q4 = fixed_point_scale_to_coarse_point_scale(sf->y_scale_fp); |
57 | 378k | } |