| /* |
| * Copyright (C) 2010 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of |
| * its contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_BIQUAD_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_BIQUAD_H_ |
| |
| #include <sys/types.h> |
| |
| #include <complex> |
| |
| #include "build/build_config.h" |
| #include "third_party/blink/renderer/platform/audio/audio_array.h" |
| #include "third_party/blink/renderer/platform/platform_export.h" |
| #include "third_party/blink/renderer/platform/wtf/allocator/allocator.h" |
| |
| namespace blink { |
| |
| // A basic biquad (two-zero / two-pole digital filter) |
| // |
| // It can be configured to a number of common and very useful filters: |
| // lowpass, highpass, shelving, parameteric, notch, allpass, ... |
| |
| class PLATFORM_EXPORT Biquad final { |
| DISALLOW_NEW(); |
| |
| public: |
| Biquad(); |
| ~Biquad(); |
| |
| void Process(const float* source_p, |
| float* dest_p, |
| uint32_t frames_to_process); |
| |
| bool HasSampleAccurateValues() const { return has_sample_accurate_values_; } |
| void SetHasSampleAccurateValues(bool is_sample_accurate) { |
| has_sample_accurate_values_ = is_sample_accurate; |
| } |
| |
| // frequency is 0 - 1 normalized, resonance and dbGain are in decibels. |
| // Q is a unitless quality factor. |
| void SetLowpassParams(int, double frequency, double resonance); |
| void SetHighpassParams(int, double frequency, double resonance); |
| void SetBandpassParams(int, double frequency, double q); |
| void SetLowShelfParams(int, double frequency, double db_gain); |
| void SetHighShelfParams(int, double frequency, double db_gain); |
| void SetPeakingParams(int, double frequency, double q, double db_gain); |
| void SetAllpassParams(int, double frequency, double q); |
| void SetNotchParams(int, double frequency, double q); |
| |
| // Resets filter state |
| void Reset(); |
| |
| // Compute tail frame based on the filter coefficents at index |
| // |coef_index|. The tail frame is the frame number where the |
| // impulse response of the filter falls below a threshold value. |
| // The maximum allowed frame value is given by |max_frame|. This |
| // limits how much work is done in computing the frame numer. |
| double TailFrame(int coef_index, double max_frame); |
| |
| // Filter response at a set of n frequencies. The magnitude and |
| // phase response are returned in magResponse and phaseResponse. |
| // The phase response is in radians. |
| void GetFrequencyResponse(int n_frequencies, |
| const float* frequency, |
| float* mag_response, |
| float* phase_response); |
| |
| private: |
| void SetNormalizedCoefficients(int, |
| double b0, |
| double b1, |
| double b2, |
| double a0, |
| double a1, |
| double a2); |
| |
| // If true, the filter coefficients are (possibly) time-varying due to a |
| // timeline automation on at least one filter parameter. |
| bool has_sample_accurate_values_; |
| |
| // Filter coefficients. The filter is defined as |
| // |
| // y[n] + m_a1*y[n-1] + m_a2*y[n-2] = m_b0*x[n] + m_b1*x[n-1] + m_b2*x[n-2]. |
| AudioDoubleArray b0_; |
| AudioDoubleArray b1_; |
| AudioDoubleArray b2_; |
| AudioDoubleArray a1_; |
| AudioDoubleArray a2_; |
| |
| #if defined(OS_MAC) |
| void ProcessFast(const float* source_p, |
| float* dest_p, |
| uint32_t frames_to_process); |
| void ProcessSliceFast(double* source_p, |
| double* dest_p, |
| double* coefficients_p, |
| uint32_t frames_to_process); |
| |
| AudioDoubleArray input_buffer_; |
| AudioDoubleArray output_buffer_; |
| |
| #endif |
| // Filter memory |
| double x1_; // input delayed by 1 sample |
| double x2_; // input delayed by 2 samples |
| double y1_; // output delayed by 1 sample |
| double y2_; // output delayed by 2 samples |
| }; |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_BIQUAD_H_ |