| /* |
| * Copyright (c) 2018 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #ifndef MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SYMMETRIC_MATRIX_BUFFER_H_ |
| #define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SYMMETRIC_MATRIX_BUFFER_H_ |
| |
| #include <algorithm> |
| #include <array> |
| #include <cstring> |
| #include <utility> |
| |
| #include "api/array_view.h" |
| #include "rtc_base/checks.h" |
| |
| namespace webrtc { |
| namespace rnn_vad { |
| |
| // Data structure to buffer the results of pair-wise comparisons between items |
| // stored in a ring buffer. Every time that the oldest item is replaced in the |
| // ring buffer, the new one is compared to the remaining items in the ring |
| // buffer. The results of such comparisons need to be buffered and automatically |
| // removed when one of the two corresponding items that have been compared is |
| // removed from the ring buffer. It is assumed that the comparison is symmetric |
| // and that comparing an item with itself is not needed. |
| template <typename T, size_t S> |
| class SymmetricMatrixBuffer { |
| static_assert(S > 2, ""); |
| |
| public: |
| SymmetricMatrixBuffer() = default; |
| SymmetricMatrixBuffer(const SymmetricMatrixBuffer&) = delete; |
| SymmetricMatrixBuffer& operator=(const SymmetricMatrixBuffer&) = delete; |
| ~SymmetricMatrixBuffer() = default; |
| // Sets the buffer values to zero. |
| void Reset() { |
| static_assert(std::is_arithmetic<T>::value, |
| "Integral or floating point required."); |
| buf_.fill(0); |
| } |
| // Pushes the results from the comparison between the most recent item and |
| // those that are still in the ring buffer. The first element in |values| must |
| // correspond to the comparison between the most recent item and the second |
| // most recent one in the ring buffer, whereas the last element in |values| |
| // must correspond to the comparison between the most recent item and the |
| // oldest one in the ring buffer. |
| void Push(rtc::ArrayView<T, S - 1> values) { |
| // Move the lower-right sub-matrix of size (S-2) x (S-2) one row up and one |
| // column left. |
| std::memmove(buf_.data(), buf_.data() + S, (buf_.size() - S) * sizeof(T)); |
| // Copy new values in the last column in the right order. |
| for (size_t i = 0; i < values.size(); ++i) { |
| const size_t index = (S - 1 - i) * (S - 1) - 1; |
| RTC_DCHECK_LE(static_cast<size_t>(0), index); |
| RTC_DCHECK_LT(index, buf_.size()); |
| buf_[index] = values[i]; |
| } |
| } |
| // Reads the value that corresponds to comparison of two items in the ring |
| // buffer having delay |delay1| and |delay2|. The two arguments must not be |
| // equal and both must be in {0, ..., S - 1}. |
| T GetValue(size_t delay1, size_t delay2) const { |
| int row = S - 1 - static_cast<int>(delay1); |
| int col = S - 1 - static_cast<int>(delay2); |
| RTC_DCHECK_NE(row, col) << "The diagonal cannot be accessed."; |
| if (row > col) |
| std::swap(row, col); // Swap to access the upper-right triangular part. |
| RTC_DCHECK_LE(0, row); |
| RTC_DCHECK_LT(row, S - 1) << "Not enforcing row < col and row != col."; |
| RTC_DCHECK_LE(1, col) << "Not enforcing row < col and row != col."; |
| RTC_DCHECK_LT(col, S); |
| const int index = row * (S - 1) + (col - 1); |
| RTC_DCHECK_LE(0, index); |
| RTC_DCHECK_LT(index, buf_.size()); |
| return buf_[index]; |
| } |
| |
| private: |
| // Encode an upper-right triangular matrix (excluding its diagonal) using a |
| // square matrix. This allows to move the data in Push() with one single |
| // operation. |
| std::array<T, (S - 1) * (S - 1)> buf_{}; |
| }; |
| |
| } // namespace rnn_vad |
| } // namespace webrtc |
| |
| #endif // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_SYMMETRIC_MATRIX_BUFFER_H_ |