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95 lines
3.1 KiB
95 lines
3.1 KiB
/*
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* Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef MODULES_AUDIO_PROCESSING_UTILITY_PFFFT_WRAPPER_H_
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#define MODULES_AUDIO_PROCESSING_UTILITY_PFFFT_WRAPPER_H_
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#include <memory>
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#include "api/array_view.h"
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// Forward declaration.
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struct PFFFT_Setup;
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namespace webrtc {
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// Pretty-Fast Fast Fourier Transform (PFFFT) wrapper class.
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// Not thread safe.
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class Pffft {
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public:
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enum class FftType { kReal, kComplex };
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// 1D floating point buffer used as input/output data type for the FFT ops.
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// It must be constructed using Pffft::CreateBuffer().
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class FloatBuffer {
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public:
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FloatBuffer(const FloatBuffer&) = delete;
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FloatBuffer& operator=(const FloatBuffer&) = delete;
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~FloatBuffer();
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rtc::ArrayView<const float> GetConstView() const;
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rtc::ArrayView<float> GetView();
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private:
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friend class Pffft;
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FloatBuffer(size_t fft_size, FftType fft_type);
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const float* const_data() const { return data_; }
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float* data() { return data_; }
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size_t size() const { return size_; }
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const size_t size_;
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float* const data_;
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};
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// TODO(https://crbug.com/webrtc/9577): Consider adding a factory and making
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// the ctor private.
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// static std::unique_ptr<Pffft> Create(size_t fft_size,
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// FftType fft_type); Ctor. |fft_size| must be a supported size (see
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// Pffft::IsValidFftSize()). If not supported, the code will crash.
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Pffft(size_t fft_size, FftType fft_type);
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Pffft(const Pffft&) = delete;
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Pffft& operator=(const Pffft&) = delete;
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~Pffft();
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// Returns true if the FFT size is supported.
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static bool IsValidFftSize(size_t fft_size, FftType fft_type);
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// Returns true if SIMD code optimizations are being used.
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static bool IsSimdEnabled();
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// Creates a buffer of the right size.
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std::unique_ptr<FloatBuffer> CreateBuffer() const;
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// TODO(https://crbug.com/webrtc/9577): Overload with rtc::ArrayView args.
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// Computes the forward fast Fourier transform.
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void ForwardTransform(const FloatBuffer& in, FloatBuffer* out, bool ordered);
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// Computes the backward fast Fourier transform.
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void BackwardTransform(const FloatBuffer& in, FloatBuffer* out, bool ordered);
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// Multiplies the frequency components of |fft_x| and |fft_y| and accumulates
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// them into |out|. The arrays must have been obtained with
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// ForwardTransform(..., /*ordered=*/false) - i.e., |fft_x| and |fft_y| must
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// not be ordered.
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void FrequencyDomainConvolve(const FloatBuffer& fft_x,
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const FloatBuffer& fft_y,
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FloatBuffer* out,
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float scaling = 1.f);
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private:
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const size_t fft_size_;
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const FftType fft_type_;
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PFFFT_Setup* pffft_status_;
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float* const scratch_buffer_;
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};
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} // namespace webrtc
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#endif // MODULES_AUDIO_PROCESSING_UTILITY_PFFFT_WRAPPER_H_
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