1 /*
2  *  Copyright (c) 2011 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_FILTER_H_
12 #define VP9_COMMON_VP9_FILTER_H_
13 
14 #include "./vpx_config.h"
15 #include "vpx/vpx_integer.h"
16 #include "vpx_ports/mem.h"
17 
18 
19 #ifdef __cplusplus
20 extern "C" {
21 #endif
22 
23 #define FILTER_BITS 7
24 
25 #define SUBPEL_BITS 4
26 #define SUBPEL_MASK ((1 << SUBPEL_BITS) - 1)
27 #define SUBPEL_SHIFTS (1 << SUBPEL_BITS)
28 #define SUBPEL_TAPS 8
29 
30 typedef enum {
31   EIGHTTAP = 0,
32   EIGHTTAP_SMOOTH = 1,
33   EIGHTTAP_SHARP = 2,
34   BILINEAR = 3,
35   SWITCHABLE = 4  /* should be the last one */
36 } INTERP_FILTER;
37 
38 typedef int16_t InterpKernel[SUBPEL_TAPS];
39 
40 const InterpKernel *vp9_get_interp_kernel(INTERP_FILTER filter);
41 
42 DECLARE_ALIGNED(256, extern const InterpKernel,
43                 vp9_bilinear_filters[SUBPEL_SHIFTS]);
44 
45 // The VP9_BILINEAR_FILTERS_2TAP macro returns a pointer to the bilinear
46 // filter kernel as a 2 tap filter.
47 #define BILINEAR_FILTERS_2TAP(x) \
48   (vp9_bilinear_filters[(x)] + SUBPEL_TAPS/2 - 1)
49 
50 #ifdef __cplusplus
51 }  // extern "C"
52 #endif
53 
54 #endif  // VP9_COMMON_VP9_FILTER_H_
55