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/*
* 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.
*/
#ifndef AOM_AV1_COMMON_SCALE_H_
#define AOM_AV1_COMMON_SCALE_H_
#include "av1/common/convolve.h"
#include "av1/common/mv.h"
#ifdef __cplusplus
extern "C" {
#endif
#define SCALE_NUMERATOR 8
#define REF_SCALE_SHIFT 14
#define REF_NO_SCALE (1 << REF_SCALE_SHIFT)
#define REF_INVALID_SCALE -1
struct scale_factors {
int x_scale_fp; // horizontal fixed point scale factor
int y_scale_fp; // vertical fixed point scale factor
int x_step_q4;
int y_step_q4;
};
// Note: Expect val to be in q4 precision
static inline int av1_scaled_x(int val, const struct scale_factors *sf) {
const int off =
(sf->x_scale_fp - (1 << REF_SCALE_SHIFT)) * (1 << (SUBPEL_BITS - 1));
const int64_t tval = (int64_t)val * sf->x_scale_fp + off;
return (int)ROUND_POWER_OF_TWO_SIGNED_64(tval,
REF_SCALE_SHIFT - SCALE_EXTRA_BITS);
}
// Note: Expect val to be in q4 precision
static inline int av1_scaled_y(int val, const struct scale_factors *sf) {
const int off =
(sf->y_scale_fp - (1 << REF_SCALE_SHIFT)) * (1 << (SUBPEL_BITS - 1));
const int64_t tval = (int64_t)val * sf->y_scale_fp + off;
return (int)ROUND_POWER_OF_TWO_SIGNED_64(tval,
REF_SCALE_SHIFT - SCALE_EXTRA_BITS);
}
// Note: Expect val to be in q4 precision
static inline int av1_unscaled_value(int val, const struct scale_factors *sf) {
(void)sf;
return val * (1 << SCALE_EXTRA_BITS);
}
MV32 av1_scale_mv(const MV *mv, int x, int y, const struct scale_factors *sf);
void av1_setup_scale_factors_for_frame(struct scale_factors *sf, int other_w,
int other_h, int this_w, int this_h);
static inline int av1_is_valid_scale(const struct scale_factors *sf) {
assert(sf != NULL);
return sf->x_scale_fp != REF_INVALID_SCALE &&
sf->y_scale_fp != REF_INVALID_SCALE;
}
static inline int av1_is_scaled(const struct scale_factors *sf) {
assert(sf != NULL);
return av1_is_valid_scale(sf) &&
(sf->x_scale_fp != REF_NO_SCALE || sf->y_scale_fp != REF_NO_SCALE);
}
// See AV1 spec, Section 6.8.6. Frame size with refs semantics.
static inline int valid_ref_frame_size(int ref_width, int ref_height,
int this_width, int this_height) {
return 2 * this_width >= ref_width && 2 * this_height >= ref_height &&
this_width <= 16 * ref_width && this_height <= 16 * ref_height;
}
#ifdef __cplusplus
} // extern "C"
#endif
#endif // AOM_AV1_COMMON_SCALE_H_