| // Copyright 2016 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_IIR_PROCESSOR_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_IIR_PROCESSOR_H_ |
| |
| #include <memory> |
| #include "third_party/blink/renderer/modules/webaudio/audio_node.h" |
| #include "third_party/blink/renderer/platform/audio/audio_dsp_kernel.h" |
| #include "third_party/blink/renderer/platform/audio/audio_dsp_kernel_processor.h" |
| #include "third_party/blink/renderer/platform/audio/iir_filter.h" |
| |
| namespace blink { |
| |
| class IIRDSPKernel; |
| |
| class IIRProcessor final : public AudioDSPKernelProcessor { |
| public: |
| IIRProcessor(float sample_rate, |
| uint32_t number_of_channels, |
| const Vector<double>& feedforward_coef, |
| const Vector<double>& feedback_coef, |
| bool is_filter_stable); |
| ~IIRProcessor() override; |
| |
| std::unique_ptr<AudioDSPKernel> CreateKernel() override; |
| |
| void Process(const AudioBus* source, |
| AudioBus* destination, |
| uint32_t frames_to_process) override; |
| |
| // Get the magnitude and phase response of the filter at the given |
| // set of frequencies (in Hz). The phase response is in radians. |
| void GetFrequencyResponse(int n_frequencies, |
| const float* frequency_hz, |
| float* mag_response, |
| float* phase_response); |
| |
| AudioDoubleArray* Feedback() { return &feedback_; } |
| AudioDoubleArray* Feedforward() { return &feedforward_; } |
| bool IsFilterStable() const { return is_filter_stable_; } |
| |
| private: |
| // The feedback and feedforward filter coefficients for the IIR filter. |
| AudioDoubleArray feedback_; |
| AudioDoubleArray feedforward_; |
| bool is_filter_stable_; |
| |
| // This holds the IIR kernel for computing the frequency response. |
| std::unique_ptr<IIRDSPKernel> response_kernel_; |
| }; |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_IIR_PROCESSOR_H_ |