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 21 extern "C" { 22 #endif 23 24 static 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 38 static 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 44 static 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 62 static 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 91 void idct4_c(const tran_low_t *input, tran_low_t *output); 92 void idct8_c(const tran_low_t *input, tran_low_t *output); 93 void idct16_c(const tran_low_t *input, tran_low_t *output); 94 void idct32_c(const tran_low_t *input, tran_low_t *output); 95 void iadst4_c(const tran_low_t *input, tran_low_t *output); 96 void iadst8_c(const tran_low_t *input, tran_low_t *output); 97 void iadst16_c(const tran_low_t *input, tran_low_t *output); 98 99 #if CONFIG_VP9_HIGHBITDEPTH 100 void vpx_highbd_idct4_c(const tran_low_t *input, tran_low_t *output, int bd); 101 void vpx_highbd_idct8_c(const tran_low_t *input, tran_low_t *output, int bd); 102 void vpx_highbd_idct16_c(const tran_low_t *input, tran_low_t *output, int bd); 103 104 void vpx_highbd_iadst4_c(const tran_low_t *input, tran_low_t *output, int bd); 105 void vpx_highbd_iadst8_c(const tran_low_t *input, tran_low_t *output, int bd); 106 void vpx_highbd_iadst16_c(const tran_low_t *input, tran_low_t *output, int bd); 107 108 static 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 114 115 static 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
