| /* |
| * Copyright (c) 2016, Alliance for Open Media. All rights reserved. |
| * |
| * This source code is subject to the terms of the BSD 2 Clause License and |
| * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License |
| * was not distributed with this source code in the LICENSE file, you can |
| * obtain it at www.aomedia.org/license/software. If the Alliance for Open |
| * Media Patent License 1.0 was not distributed with this source code in the |
| * PATENTS file, you can obtain it at www.aomedia.org/license/patent. |
| */ |
| |
| #include "config/aom_dsp_rtcd.h" |
| #include "config/av1_rtcd.h" |
| |
| #include "av1/common/filter.h" |
| #include "av1/common/scale.h" |
| #include "aom_dsp/aom_filter.h" |
| |
| static int get_fixed_point_scale_factor(int other_size, int this_size) { |
| // Calculate scaling factor once for each reference frame |
| // and use fixed point scaling factors in decoding and encoding routines. |
| // Hardware implementations can calculate scale factor in device driver |
| // and use multiplication and shifting on hardware instead of division. |
| return ((other_size << REF_SCALE_SHIFT) + this_size / 2) / this_size; |
| } |
| |
| // Given the fixed point scale, calculate coarse point scale. |
| static int fixed_point_scale_to_coarse_point_scale(int scale_fp) { |
| return ROUND_POWER_OF_TWO(scale_fp, REF_SCALE_SHIFT - SCALE_SUBPEL_BITS); |
| } |
| |
| // Note: x and y are integer precision, mvq4 is q4 precision. |
| MV32 av1_scale_mv(const MV *mvq4, int x, int y, |
| const struct scale_factors *sf) { |
| const int x_off_q4 = av1_scaled_x(x << SUBPEL_BITS, sf); |
| const int y_off_q4 = av1_scaled_y(y << SUBPEL_BITS, sf); |
| const MV32 res = { |
| av1_scaled_y((y << SUBPEL_BITS) + mvq4->row, sf) - y_off_q4, |
| av1_scaled_x((x << SUBPEL_BITS) + mvq4->col, sf) - x_off_q4 |
| }; |
| return res; |
| } |
| |
| void av1_setup_scale_factors_for_frame(struct scale_factors *sf, int other_w, |
| int other_h, int this_w, int this_h) { |
| if (!valid_ref_frame_size(other_w, other_h, this_w, this_h)) { |
| sf->x_scale_fp = REF_INVALID_SCALE; |
| sf->y_scale_fp = REF_INVALID_SCALE; |
| return; |
| } |
| |
| sf->x_scale_fp = get_fixed_point_scale_factor(other_w, this_w); |
| sf->y_scale_fp = get_fixed_point_scale_factor(other_h, this_h); |
| |
| sf->x_step_q4 = fixed_point_scale_to_coarse_point_scale(sf->x_scale_fp); |
| sf->y_step_q4 = fixed_point_scale_to_coarse_point_scale(sf->y_scale_fp); |
| } |