1/*
2 *  Copyright (c) 2010 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 VPX_DSP_INV_TXFM_H_
12#define VPX_DSP_INV_TXFM_H_
13
14#include <assert.h>
15
16#include "./vpx_config.h"
17#include "vpx_dsp/txfm_common.h"
18#include "vpx_ports/mem.h"
19
20#ifdef __cplusplus
21extern "C" {
22#endif
23
24static INLINE tran_low_t check_range(tran_high_t input) {
25#if CONFIG_COEFFICIENT_RANGE_CHECKING
26  // For valid VP9 input streams, intermediate stage coefficients should always
27  // stay within the range of a signed 16 bit integer. Coefficients can go out
28  // of this range for invalid/corrupt VP9 streams. However, strictly checking
29  // this range for every intermediate coefficient can burdensome for a decoder,
30  // therefore the following assertion is only enabled when configured with
31  // --enable-coefficient-range-checking.
32  assert(INT16_MIN <= input);
33  assert(input <= INT16_MAX);
34#endif  // CONFIG_COEFFICIENT_RANGE_CHECKING
35  return (tran_low_t)input;
36}
37
38static INLINE tran_low_t dct_const_round_shift(tran_high_t input) {
39  tran_high_t rv = ROUND_POWER_OF_TWO(input, DCT_CONST_BITS);
40  return check_range(rv);
41}
42
43#if CONFIG_VP9_HIGHBITDEPTH
44static INLINE tran_low_t highbd_check_range(tran_high_t input,
45                                            int bd) {
46#if CONFIG_COEFFICIENT_RANGE_CHECKING
47  // For valid highbitdepth VP9 streams, intermediate stage coefficients will
48  // stay within the ranges:
49  // - 8 bit: signed 16 bit integer
50  // - 10 bit: signed 18 bit integer
51  // - 12 bit: signed 20 bit integer
52  const int32_t int_max = (1 << (7 + bd)) - 1;
53  const int32_t int_min = -int_max - 1;
54  assert(int_min <= input);
55  assert(input <= int_max);
56  (void) int_min;
57#endif  // CONFIG_COEFFICIENT_RANGE_CHECKING
58  (void) bd;
59  return (tran_low_t)input;
60}
61
62static INLINE tran_low_t highbd_dct_const_round_shift(tran_high_t input,
63                                                      int bd) {
64  tran_high_t rv = ROUND_POWER_OF_TWO(input, DCT_CONST_BITS);
65  return highbd_check_range(rv, bd);
66}
67#endif  // CONFIG_VP9_HIGHBITDEPTH
68
69#if CONFIG_EMULATE_HARDWARE
70// When CONFIG_EMULATE_HARDWARE is 1 the transform performs a
71// non-normative method to handle overflows. A stream that causes
72// overflows  in the inverse transform is considered invalid in VP9,
73// and a hardware implementer is free to choose any reasonable
74// method to handle overflows. However to aid in hardware
75// verification they can use a specific implementation of the
76// WRAPLOW() macro below that is identical to their intended
77// hardware implementation (and also use configure options to trigger
78// the C-implementation of the transform).
79//
80// The particular WRAPLOW implementation below performs strict
81// overflow wrapping to match common hardware implementations.
82// bd of 8 uses trans_low with 16bits, need to remove 16bits
83// bd of 10 uses trans_low with 18bits, need to remove 14bits
84// bd of 12 uses trans_low with 20bits, need to remove 12bits
85// bd of x uses trans_low with 8+x bits, need to remove 24-x bits
86#define WRAPLOW(x, bd) ((((int32_t)(x)) << (24 - bd)) >> (24 - bd))
87#else
88#define WRAPLOW(x, bd) ((int32_t)(x))
89#endif  // CONFIG_EMULATE_HARDWARE
90
91void idct4_c(const tran_low_t *input, tran_low_t *output);
92void idct8_c(const tran_low_t *input, tran_low_t *output);
93void idct16_c(const tran_low_t *input, tran_low_t *output);
94void idct32_c(const tran_low_t *input, tran_low_t *output);
95void iadst4_c(const tran_low_t *input, tran_low_t *output);
96void iadst8_c(const tran_low_t *input, tran_low_t *output);
97void iadst16_c(const tran_low_t *input, tran_low_t *output);
98
99#if CONFIG_VP9_HIGHBITDEPTH
100void vpx_highbd_idct4_c(const tran_low_t *input, tran_low_t *output, int bd);
101void vpx_highbd_idct8_c(const tran_low_t *input, tran_low_t *output, int bd);
102void vpx_highbd_idct16_c(const tran_low_t *input, tran_low_t *output, int bd);
103
104void vpx_highbd_iadst4_c(const tran_low_t *input, tran_low_t *output, int bd);
105void vpx_highbd_iadst8_c(const tran_low_t *input, tran_low_t *output, int bd);
106void vpx_highbd_iadst16_c(const tran_low_t *input, tran_low_t *output, int bd);
107
108static INLINE uint16_t highbd_clip_pixel_add(uint16_t dest, tran_high_t trans,
109                                             int bd) {
110  trans = WRAPLOW(trans, bd);
111  return clip_pixel_highbd(WRAPLOW(dest + trans, bd), bd);
112}
113#endif
114
115static INLINE uint8_t clip_pixel_add(uint8_t dest, tran_high_t trans) {
116  trans = WRAPLOW(trans, 8);
117  return clip_pixel(WRAPLOW(dest + trans, 8));
118}
119#ifdef __cplusplus
120}  // extern "C"
121#endif
122
123#endif  // VPX_DSP_INV_TXFM_H_
124