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 #ifndef VP9_COMMON_VP9_SCALE_H_
12 #define VP9_COMMON_VP9_SCALE_H_
13 
14 #include "vp9/common/vp9_mv.h"
15 #include "vp9/common/vp9_convolve.h"
16 
17 #ifdef __cplusplus
18 extern "C" {
19 #endif
20 
21 #define REF_SCALE_SHIFT 14
22 #define REF_NO_SCALE (1 << REF_SCALE_SHIFT)
23 #define REF_INVALID_SCALE -1
24 
25 struct scale_factors {
26   int x_scale_fp;   // horizontal fixed point scale factor
27   int y_scale_fp;   // vertical fixed point scale factor
28   int x_step_q4;
29   int y_step_q4;
30 
31   int (*scale_value_x)(int val, const struct scale_factors *sf);
32   int (*scale_value_y)(int val, const struct scale_factors *sf);
33 
34   convolve_fn_t predict[2][2][2];  // horiz, vert, avg
35 };
36 
37 MV32 vp9_scale_mv(const MV *mv, int x, int y, const struct scale_factors *sf);
38 
39 void vp9_setup_scale_factors_for_frame(struct scale_factors *sf,
40                                        int other_w, int other_h,
41                                        int this_w, int this_h);
42 
vp9_is_valid_scale(const struct scale_factors * sf)43 static INLINE int vp9_is_valid_scale(const struct scale_factors *sf) {
44   return sf->x_scale_fp != REF_INVALID_SCALE &&
45          sf->y_scale_fp != REF_INVALID_SCALE;
46 }
47 
vp9_is_scaled(const struct scale_factors * sf)48 static INLINE int vp9_is_scaled(const struct scale_factors *sf) {
49   return vp9_is_valid_scale(sf) &&
50          (sf->x_scale_fp != REF_NO_SCALE || sf->y_scale_fp != REF_NO_SCALE);
51 }
52 
valid_ref_frame_size(int ref_width,int ref_height,int this_width,int this_height)53 static INLINE int valid_ref_frame_size(int ref_width, int ref_height,
54                                       int this_width, int this_height) {
55   return 2 * this_width >= ref_width &&
56          2 * this_height >= ref_height &&
57          this_width <= 16 * ref_width &&
58          this_height <= 16 * ref_height;
59 }
60 
61 #ifdef __cplusplus
62 }  // extern "C"
63 #endif
64 
65 #endif  // VP9_COMMON_VP9_SCALE_H_
66