alexander | 3c79893 | 2021-03-26 21:42:19 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2021 Arm Limited. All rights reserved. |
| 3 | * SPDX-License-Identifier: Apache-2.0 |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | */ |
| 17 | #ifndef AUDIO_UTILS_HPP |
| 18 | #define AUDIO_UTILS_HPP |
| 19 | |
| 20 | #include <cstddef> |
| 21 | #include <cstdint> |
| 22 | |
| 23 | namespace arm { |
| 24 | namespace app { |
| 25 | namespace audio { |
| 26 | |
| 27 | template<class T> |
| 28 | class SlidingWindow { |
| 29 | public: |
| 30 | |
| 31 | /** |
| 32 | * @brief Creates the window slider through the given data. |
| 33 | * |
| 34 | * @param[in] data Pointer to the data to slide through. |
| 35 | * @param[in] dataSize Size in T type elements wise. |
| 36 | * @param[in] windowSize Sliding window size in T type wise elements. |
| 37 | * @param[in] stride Stride size in T type wise elements. |
| 38 | */ |
| 39 | SlidingWindow(T *data, size_t dataSize, |
| 40 | size_t windowSize, size_t stride) { |
| 41 | m_start = data; |
| 42 | m_dataSize = dataSize; |
| 43 | m_size = windowSize; |
| 44 | m_stride = stride; |
| 45 | } |
| 46 | |
| 47 | SlidingWindow() = default; |
| 48 | |
| 49 | ~SlidingWindow() = default; |
| 50 | |
| 51 | /** |
| 52 | * @brief Get the next data window. |
| 53 | * @return Pointer to the next window, if next window is not available nullptr is returned. |
| 54 | */ |
| 55 | virtual T *Next() { |
| 56 | if (HasNext()) { |
| 57 | m_count++; |
| 58 | return m_start + Index() * m_stride; |
| 59 | } else { |
| 60 | return nullptr; |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * @brief Checks if the next data portion is available. |
| 66 | * @return true if next data portion is available. |
| 67 | */ |
| 68 | virtual bool HasNext() { |
| 69 | return m_size + m_count * m_stride <= m_dataSize; |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * @brief Reset the slider to the initial position. |
| 74 | */ |
| 75 | virtual void Reset() { |
| 76 | m_count = 0; |
| 77 | } |
| 78 | |
| 79 | /** |
| 80 | * @brief Resets the slider to the start of the new data. |
| 81 | * New data size MUST be the same as the old one. |
| 82 | * @param[in] newStart Pointer to the new data to slide through. |
| 83 | */ |
| 84 | virtual void Reset(T *newStart) { |
| 85 | m_start = newStart; |
| 86 | Reset(); |
| 87 | } |
| 88 | |
| 89 | /** |
| 90 | * @brief Gets current index of the sliding window. |
| 91 | * @return Current position of the sliding window in number of strides. |
| 92 | */ |
| 93 | size_t Index() { |
| 94 | return m_count == 0? 0: m_count - 1; |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * @brief Gets the index from the start of the data where the next window will begin. |
| 99 | * While Index() returns the index of sliding window itself this function |
| 100 | * returns the index of the data element itself. |
| 101 | * @return Index from the start of the data where the next sliding window will begin. |
| 102 | */ |
| 103 | virtual uint32_t NextWindowStartIndex() { |
| 104 | return m_count == 0? 0: ((m_count) * m_stride); |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * @brief Go to given sliding window index. |
| 109 | * @param[in] index New position of the sliding window. If index is invalid |
| 110 | * (greater than possible range of strides) then next call to Next() will return nullptr. |
| 111 | */ |
| 112 | void FastForward(size_t index) { |
| 113 | m_count = index; |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | * @brief Calculates whole number of times the window can stride through the given data. |
| 118 | * @return Maximum number of whole strides. |
| 119 | */ |
| 120 | size_t TotalStrides() { |
| 121 | if (m_size > m_dataSize) { |
| 122 | return 0; |
| 123 | } |
| 124 | return ((m_dataSize - m_size)/m_stride); |
| 125 | } |
| 126 | |
alexander | 3c79893 | 2021-03-26 21:42:19 +0000 | [diff] [blame] | 127 | |
| 128 | protected: |
| 129 | T *m_start = nullptr; |
| 130 | size_t m_dataSize = 0; |
| 131 | size_t m_size = 0; |
| 132 | size_t m_stride = 0; |
| 133 | size_t m_count = 0; |
| 134 | }; |
| 135 | |
| 136 | /* |
alexander | 80eecfb | 2021-07-06 19:47:59 +0100 | [diff] [blame] | 137 | * Sliding window that will cover the whole length of the input, even if |
alexander | 3c79893 | 2021-03-26 21:42:19 +0000 | [diff] [blame] | 138 | * this means the last window is not a full window length. |
| 139 | */ |
| 140 | template<class T> |
alexander | 80eecfb | 2021-07-06 19:47:59 +0100 | [diff] [blame] | 141 | class FractionalSlidingWindow : public SlidingWindow<T> { |
alexander | 3c79893 | 2021-03-26 21:42:19 +0000 | [diff] [blame] | 142 | public: |
| 143 | using SlidingWindow<T>::SlidingWindow; |
| 144 | |
| 145 | /** |
| 146 | * @brief Checks if the next data portion is available. |
| 147 | * @return true if next data portion is available. |
| 148 | */ |
| 149 | bool HasNext() { |
| 150 | return this->m_count < 1 + this->FractionalTotalStrides() && (this->NextWindowStartIndex() < this->m_dataSize); |
| 151 | } |
alexander | 80eecfb | 2021-07-06 19:47:59 +0100 | [diff] [blame] | 152 | |
| 153 | /** |
| 154 | * @brief Calculates number of times the window can stride through the given data. |
| 155 | * May not be a whole number. |
| 156 | * @return Number of strides to cover all data. |
| 157 | */ |
| 158 | float FractionalTotalStrides() { |
| 159 | if (this->m_dataSize < this->m_size) { |
| 160 | return 0; |
| 161 | } else { |
| 162 | return ((this->m_dataSize - this->m_size) / static_cast<float>(this->m_stride)); |
| 163 | } |
| 164 | } |
alexander | 3c79893 | 2021-03-26 21:42:19 +0000 | [diff] [blame] | 165 | }; |
| 166 | |
| 167 | |
| 168 | } /* namespace audio */ |
| 169 | } /* namespace app */ |
| 170 | } /* namespace arm */ |
| 171 | |
| 172 | #endif /* AUDIO_UTILS_HPP */ |