1 /* 2 * Copyright (c) 2019 The WebRTC 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 MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_ 12 #define MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_ 13 14 #include <vector> 15 16 #include "api/array_view.h" 17 #include "modules/audio_processing/ns/ns_common.h" 18 19 namespace webrtc { 20 21 // Wrapper class providing 256 point FFT functionality. 22 class NrFft { 23 public: 24 NrFft(); 25 NrFft(const NrFft&) = delete; 26 NrFft& operator=(const NrFft&) = delete; 27 28 // Transforms the signal from time to frequency domain. 29 void Fft(rtc::ArrayView<float, kFftSize> time_data, 30 rtc::ArrayView<float, kFftSize> real, 31 rtc::ArrayView<float, kFftSize> imag); 32 33 // Transforms the signal from frequency to time domain. 34 void Ifft(rtc::ArrayView<const float> real, 35 rtc::ArrayView<const float> imag, 36 rtc::ArrayView<float> time_data); 37 38 private: 39 std::vector<size_t> bit_reversal_state_; 40 std::vector<float> tables_; 41 }; 42 43 } // namespace webrtc 44 45 #endif // MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_ 46