media/libeffects/hapticgenerator/Processors.cpp - platform/frameworks/av - Git at Google

 /*
  * Copyright (C) 2020 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #define LOG_TAG "EffectHG_Processors"
 //#define LOG_NDEBUG 0
 #include <utils/Log.h>

 #include <assert.h>

 #include <cmath>

 #include "Processors.h"

 #if defined(__aarch64__) || defined(__ARM_NEON__)
 #ifndef USE_NEON
 #define USE_NEON (true)
 #endif
 #else
 #define USE_NEON (false)
 #endif
 #if USE_NEON
 #include <arm_neon.h>
 #endif

 namespace android::audio_effect::haptic_generator {

 float getRealPoleZ(float cornerFrequency, float sampleRate) {
     // This will be a pole of a first order filter.
     float realPoleS = -2 * M_PI * cornerFrequency;
     return exp(realPoleS / sampleRate); // zero-pole matching
 }

 std::pair<float, float> getComplexPoleZ(float ringingFrequency, float q, float sampleRate) {
     // This is the pole for 1/(s^2 + s/q + 1) in normalized frequency. The other pole is
     // the complex conjugate of this.
     float poleImagS = 2 * M_PI * ringingFrequency;
     float poleRealS = -poleImagS / (2 * q);
     float poleRadius = exp(poleRealS / sampleRate);
     float poleImagZ = poleRadius * sin(poleImagS / sampleRate);
     float poleRealZ = poleRadius * cos(poleImagS / sampleRate);
     return {poleRealZ, poleImagZ};
 }

 // Implementation of Ramp

 Ramp::Ramp(size_t channelCount) : mChannelCount(channelCount) {}

 void Ramp::process(float *out, const float *in, size_t frameCount) {
     size_t i = 0;
 #if USE_NEON
     size_t sampleCount = frameCount * mChannelCount;
     float32x2_t allZero = vdup_n_f32(0.0f);
     while (i + 1 < sampleCount) {
         vst1_f32(out, vmax_f32(vld1_f32(in), allZero));
         in += 2;
         out += 2;
         i += 2;
     }
 #endif // USE_NEON
     for (; i < frameCount * mChannelCount; ++i) {
         *out = *in >= 0.0f ? *in : 0.0f;
         out++;
         in++;
     }
 }

 // Implementation of SlowEnvelope

 SlowEnvelope::SlowEnvelope(
         float cornerFrequency,
         float sampleRate,
         float normalizationPower,
         float envOffset,
         size_t channelCount)
         : mLpf(createLPF(cornerFrequency, sampleRate, channelCount)),
           mNormalizationPower(normalizationPower),
           mEnvOffset(envOffset),
           mChannelCount(channelCount) {}

 void SlowEnvelope::process(float* out, const float* in, size_t frameCount) {
     size_t sampleCount = frameCount * mChannelCount;
     if (sampleCount > mLpfOutBuffer.size()) {
         mLpfOutBuffer.resize(sampleCount);
         mLpfInBuffer.resize(sampleCount);
     }
     for (size_t i = 0; i < sampleCount; ++i) {
         mLpfInBuffer[i] = fabs(in[i]);
     }
     mLpf->process(mLpfOutBuffer.data(), mLpfInBuffer.data(), frameCount);
     for (size_t i = 0; i < sampleCount; ++i) {
         out[i] = in[i] * pow(mLpfOutBuffer[i] + mEnvOffset, mNormalizationPower);
     }
 }

 void SlowEnvelope::setNormalizationPower(float normalizationPower) {
     mNormalizationPower = normalizationPower;
 }

 void SlowEnvelope::clear() {
     mLpf->clear();
 }

 // Implementation of distortion

 Distortion::Distortion(
         float cornerFrequency,
         float sampleRate,
         float inputGain,
         float cubeThreshold,
         float outputGain,
         size_t channelCount)
         : mLpf(createLPF2(cornerFrequency, sampleRate, channelCount)),
           mSampleRate(sampleRate),
           mCornerFrequency(cornerFrequency),
           mInputGain(inputGain),
           mCubeThreshold(cubeThreshold),
           mOutputGain(outputGain),
           mChannelCount(channelCount) {}

 void Distortion::process(float *out, const float *in, size_t frameCount) {
     size_t sampleCount = frameCount * mChannelCount;
     if (sampleCount > mLpfInBuffer.size()) {
         mLpfInBuffer.resize(sampleCount);
     }
     for (size_t i = 0; i < sampleCount; ++i) {
         const float x = mInputGain * in[i];
         mLpfInBuffer[i] = x * x * x / (mCubeThreshold + x * x);  // "Coring" nonlinearity.
     }
     mLpf->process(out, mLpfInBuffer.data(), frameCount);  // Reduce 3*F components.
     for (size_t i = 0; i < sampleCount; ++i) {
         const float x = out[i];
         out[i] = mOutputGain * x / (1.0f + fabs(x));  // Soft limiter.
     }
 }

 void Distortion::setCornerFrequency(float cornerFrequency) {
     mCornerFrequency = cornerFrequency;
     BiquadFilterCoefficients coefficient = lpfCoefs(cornerFrequency, mSampleRate);
     mLpf->setCoefficients(coefficient);
 }

 void Distortion::setInputGain(float inputGain) {
     mInputGain = inputGain;
 }

 void Distortion::setCubeThrehold(float cubeThreshold) {
     mCubeThreshold = cubeThreshold;
 }

 void Distortion::setOutputGain(float outputGain) {
     mOutputGain = outputGain;
 }

 void Distortion::clear() {
     mLpf->clear();
 }


 // Implementation of helper functions

 BiquadFilterCoefficients cascadeFirstOrderFilters(const BiquadFilterCoefficients &coefs1,
                                                    const BiquadFilterCoefficients &coefs2) {
     assert(coefs1[2] == 0.0f);
     assert(coefs2[2] == 0.0f);
     assert(coefs1[4] == 0.0f);
     assert(coefs2[4] == 0.0f);
     return {coefs1[0] * coefs2[0],
             coefs1[0] * coefs2[1] + coefs1[1] * coefs2[0],
             coefs1[1] * coefs2[1],
             coefs1[3] + coefs2[3],
             coefs1[3] * coefs2[3]};
 }

 BiquadFilterCoefficients lpfCoefs(const float cornerFrequency, const float sampleRate) {
     BiquadFilterCoefficients coefficient;
     float realPoleZ = getRealPoleZ(cornerFrequency, sampleRate);
     // This is a zero at nyquist
     coefficient[0] = 0.5f * (1 - realPoleZ);
     coefficient[1] = coefficient[0];
     coefficient[2] = 0.0f;
     coefficient[3] = -realPoleZ; // This is traditional 1/(s+1) filter
     coefficient[4] = 0.0f;
     return coefficient;
 }

 BiquadFilterCoefficients bpfCoefs(const float ringingFrequency,
                                   const float q,
                                   const float sampleRate) {
     BiquadFilterCoefficients coefficient;
     const auto [real, img] = getComplexPoleZ(ringingFrequency, q, sampleRate);
     // Note: this is not a standard cookbook BPF, but a low pass filter with zero at DC
     coefficient[0] = 1.0f;
     coefficient[1] = -1.0f;
     coefficient[2] = 0.0f;
     coefficient[3] = -2 * real;
     coefficient[4] = real * real + img * img;
     return coefficient;
 }

 BiquadFilterCoefficients bsfCoefs(const float ringingFrequency,
                                   const float zq,
                                   const float pq,
                                   const float sampleRate) {
     BiquadFilterCoefficients coefficient;
     const auto [zeroReal, zeroImg] = getComplexPoleZ(ringingFrequency, zq, sampleRate);
     float zeroCoeff1 = -2 * zeroReal;
     float zeroCoeff2 = zeroReal* zeroReal + zeroImg * zeroImg;
     const auto [poleReal, poleImg] = getComplexPoleZ(ringingFrequency, pq, sampleRate);
     float poleCoeff1 = -2 * poleReal;
     float poleCoeff2 = poleReal * poleReal + poleImg * poleImg;
     const float norm = (1.0f + poleCoeff1 + poleCoeff2) / (1.0f + zeroCoeff1 + zeroCoeff2);
     coefficient[0] = 1.0f * norm;
     coefficient[1] = zeroCoeff1 * norm;
     coefficient[2] = zeroCoeff2 * norm;
     coefficient[3] = poleCoeff1;
     coefficient[4] = poleCoeff2;
     return coefficient;
 }

 std::shared_ptr<HapticBiquadFilter> createLPF(const float cornerFrequency,
                                         const float sampleRate,
                                         const size_t channelCount) {
     BiquadFilterCoefficients coefficient = lpfCoefs(cornerFrequency, sampleRate);
     return std::make_shared<HapticBiquadFilter>(channelCount, coefficient);
 }

 std::shared_ptr<HapticBiquadFilter> createLPF2(const float cornerFrequency,
                                          const float sampleRate,
                                          const size_t channelCount) {
     BiquadFilterCoefficients coefficient = lpfCoefs(cornerFrequency, sampleRate);
     return std::make_shared<HapticBiquadFilter>(
             channelCount, cascadeFirstOrderFilters(coefficient, coefficient));
 }

 std::shared_ptr<HapticBiquadFilter> createHPF2(const float cornerFrequency,
                                          const float sampleRate,
                                          const size_t channelCount) {
     BiquadFilterCoefficients coefficient;
     // Note: this is valid only when corner frequency is less than nyquist / 2.
     float realPoleZ = getRealPoleZ(cornerFrequency, sampleRate);

     // Note: this is a zero at DC
     coefficient[0] = 0.5f * (1 + realPoleZ);
     coefficient[1] = -coefficient[0];
     coefficient[2] = 0.0f;
     coefficient[3] = -realPoleZ;
     coefficient[4] = 0.0f;
     return std::make_shared<HapticBiquadFilter>(
             channelCount, cascadeFirstOrderFilters(coefficient, coefficient));
 }

 std::shared_ptr<HapticBiquadFilter> createBPF(const float ringingFrequency,
                                         const float q,
                                         const float sampleRate,
                                         const size_t channelCount) {
     BiquadFilterCoefficients coefficient = bpfCoefs(ringingFrequency, q, sampleRate);
     return std::make_shared<HapticBiquadFilter>(channelCount, coefficient);
 }

 std::shared_ptr<HapticBiquadFilter> createBSF(const float ringingFrequency,
                                         const float zq,
                                         const float pq,
                                         const float sampleRate,
                                         const size_t channelCount) {
     BiquadFilterCoefficients coefficient = bsfCoefs(ringingFrequency, zq, pq, sampleRate);
     return std::make_shared<HapticBiquadFilter>(channelCount, coefficient);
 }

 } // namespace android::audio_effect::haptic_generator
	/*
	* Copyright (C) 2020 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#define LOG_TAG "EffectHG_Processors"
	//#define LOG_NDEBUG 0
	#include <utils/Log.h>

	#include <assert.h>

	#include <cmath>

	#include "Processors.h"

	#if defined(__aarch64__) \|\| defined(__ARM_NEON__)
	#ifndef USE_NEON
	#define USE_NEON (true)
	#endif
	#else
	#define USE_NEON (false)
	#endif
	#if USE_NEON
	#include <arm_neon.h>
	#endif

	namespace android::audio_effect::haptic_generator {

	float getRealPoleZ(float cornerFrequency, float sampleRate) {
	// This will be a pole of a first order filter.
	float realPoleS = -2 * M_PI * cornerFrequency;
	return exp(realPoleS / sampleRate); // zero-pole matching
	}

	std::pair<float, float> getComplexPoleZ(float ringingFrequency, float q, float sampleRate) {
	// This is the pole for 1/(s^2 + s/q + 1) in normalized frequency. The other pole is
	// the complex conjugate of this.
	float poleImagS = 2 * M_PI * ringingFrequency;
	float poleRealS = -poleImagS / (2 * q);
	float poleRadius = exp(poleRealS / sampleRate);
	float poleImagZ = poleRadius * sin(poleImagS / sampleRate);
	float poleRealZ = poleRadius * cos(poleImagS / sampleRate);
	return {poleRealZ, poleImagZ};
	}

	// Implementation of Ramp

	Ramp::Ramp(size_t channelCount) : mChannelCount(channelCount) {}

	void Ramp::process(float out, const float in, size_t frameCount) {
	size_t i = 0;
	#if USE_NEON
	size_t sampleCount = frameCount * mChannelCount;
	float32x2_t allZero = vdup_n_f32(0.0f);
	while (i + 1 < sampleCount) {
	vst1_f32(out, vmax_f32(vld1_f32(in), allZero));
	in += 2;
	out += 2;
	i += 2;
	}
	#endif // USE_NEON
	for (; i < frameCount * mChannelCount; ++i) {
	out = in >= 0.0f ? *in : 0.0f;
	out++;
	in++;
	}
	}

	// Implementation of SlowEnvelope

	SlowEnvelope::SlowEnvelope(
	float cornerFrequency,
	float sampleRate,
	float normalizationPower,
	float envOffset,
	size_t channelCount)
	: mLpf(createLPF(cornerFrequency, sampleRate, channelCount)),
	mNormalizationPower(normalizationPower),
	mEnvOffset(envOffset),
	mChannelCount(channelCount) {}

	void SlowEnvelope::process(float* out, const float* in, size_t frameCount) {
	size_t sampleCount = frameCount * mChannelCount;
	if (sampleCount > mLpfOutBuffer.size()) {
	mLpfOutBuffer.resize(sampleCount);
	mLpfInBuffer.resize(sampleCount);
	}
	for (size_t i = 0; i < sampleCount; ++i) {
	mLpfInBuffer[i] = fabs(in[i]);
	}
	mLpf->process(mLpfOutBuffer.data(), mLpfInBuffer.data(), frameCount);
	for (size_t i = 0; i < sampleCount; ++i) {
	out[i] = in[i] * pow(mLpfOutBuffer[i] + mEnvOffset, mNormalizationPower);
	}
	}

	void SlowEnvelope::setNormalizationPower(float normalizationPower) {
	mNormalizationPower = normalizationPower;
	}

	void SlowEnvelope::clear() {
	mLpf->clear();
	}

	// Implementation of distortion

	Distortion::Distortion(
	float cornerFrequency,
	float sampleRate,
	float inputGain,
	float cubeThreshold,
	float outputGain,
	size_t channelCount)
	: mLpf(createLPF2(cornerFrequency, sampleRate, channelCount)),
	mSampleRate(sampleRate),
	mCornerFrequency(cornerFrequency),
	mInputGain(inputGain),
	mCubeThreshold(cubeThreshold),
	mOutputGain(outputGain),
	mChannelCount(channelCount) {}

	void Distortion::process(float out, const float in, size_t frameCount) {
	size_t sampleCount = frameCount * mChannelCount;
	if (sampleCount > mLpfInBuffer.size()) {
	mLpfInBuffer.resize(sampleCount);
	}
	for (size_t i = 0; i < sampleCount; ++i) {
	const float x = mInputGain * in[i];
	mLpfInBuffer[i] = x * x * x / (mCubeThreshold + x * x); // "Coring" nonlinearity.
	}
	mLpf->process(out, mLpfInBuffer.data(), frameCount); // Reduce 3*F components.
	for (size_t i = 0; i < sampleCount; ++i) {
	const float x = out[i];
	out[i] = mOutputGain * x / (1.0f + fabs(x)); // Soft limiter.
	}
	}

	void Distortion::setCornerFrequency(float cornerFrequency) {
	mCornerFrequency = cornerFrequency;
	BiquadFilterCoefficients coefficient = lpfCoefs(cornerFrequency, mSampleRate);
	mLpf->setCoefficients(coefficient);
	}

	void Distortion::setInputGain(float inputGain) {
	mInputGain = inputGain;
	}

	void Distortion::setCubeThrehold(float cubeThreshold) {
	mCubeThreshold = cubeThreshold;
	}

	void Distortion::setOutputGain(float outputGain) {
	mOutputGain = outputGain;
	}

	void Distortion::clear() {
	mLpf->clear();
	}


	// Implementation of helper functions

	BiquadFilterCoefficients cascadeFirstOrderFilters(const BiquadFilterCoefficients &coefs1,
	const BiquadFilterCoefficients &coefs2) {
	assert(coefs1[2] == 0.0f);
	assert(coefs2[2] == 0.0f);
	assert(coefs1[4] == 0.0f);
	assert(coefs2[4] == 0.0f);
	return {coefs1[0] * coefs2[0],
	coefs1[0] * coefs2[1] + coefs1[1] * coefs2[0],
	coefs1[1] * coefs2[1],
	coefs1[3] + coefs2[3],
	coefs1[3] * coefs2[3]};
	}

	BiquadFilterCoefficients lpfCoefs(const float cornerFrequency, const float sampleRate) {
	BiquadFilterCoefficients coefficient;
	float realPoleZ = getRealPoleZ(cornerFrequency, sampleRate);
	// This is a zero at nyquist
	coefficient[0] = 0.5f * (1 - realPoleZ);
	coefficient[1] = coefficient[0];
	coefficient[2] = 0.0f;
	coefficient[3] = -realPoleZ; // This is traditional 1/(s+1) filter
	coefficient[4] = 0.0f;
	return coefficient;
	}

	BiquadFilterCoefficients bpfCoefs(const float ringingFrequency,
	const float q,
	const float sampleRate) {
	BiquadFilterCoefficients coefficient;
	const auto [real, img] = getComplexPoleZ(ringingFrequency, q, sampleRate);
	// Note: this is not a standard cookbook BPF, but a low pass filter with zero at DC
	coefficient[0] = 1.0f;
	coefficient[1] = -1.0f;
	coefficient[2] = 0.0f;
	coefficient[3] = -2 * real;
	coefficient[4] = real * real + img * img;
	return coefficient;
	}

	BiquadFilterCoefficients bsfCoefs(const float ringingFrequency,
	const float zq,
	const float pq,
	const float sampleRate) {
	BiquadFilterCoefficients coefficient;
	const auto [zeroReal, zeroImg] = getComplexPoleZ(ringingFrequency, zq, sampleRate);
	float zeroCoeff1 = -2 * zeroReal;
	float zeroCoeff2 = zeroReal* zeroReal + zeroImg * zeroImg;
	const auto [poleReal, poleImg] = getComplexPoleZ(ringingFrequency, pq, sampleRate);
	float poleCoeff1 = -2 * poleReal;
	float poleCoeff2 = poleReal * poleReal + poleImg * poleImg;
	const float norm = (1.0f + poleCoeff1 + poleCoeff2) / (1.0f + zeroCoeff1 + zeroCoeff2);
	coefficient[0] = 1.0f * norm;
	coefficient[1] = zeroCoeff1 * norm;
	coefficient[2] = zeroCoeff2 * norm;
	coefficient[3] = poleCoeff1;
	coefficient[4] = poleCoeff2;
	return coefficient;
	}

	std::shared_ptr<HapticBiquadFilter> createLPF(const float cornerFrequency,
	const float sampleRate,
	const size_t channelCount) {
	BiquadFilterCoefficients coefficient = lpfCoefs(cornerFrequency, sampleRate);
	return std::make_shared<HapticBiquadFilter>(channelCount, coefficient);
	}

	std::shared_ptr<HapticBiquadFilter> createLPF2(const float cornerFrequency,
	const float sampleRate,
	const size_t channelCount) {
	BiquadFilterCoefficients coefficient = lpfCoefs(cornerFrequency, sampleRate);
	return std::make_shared<HapticBiquadFilter>(
	channelCount, cascadeFirstOrderFilters(coefficient, coefficient));
	}

	std::shared_ptr<HapticBiquadFilter> createHPF2(const float cornerFrequency,
	const float sampleRate,
	const size_t channelCount) {
	BiquadFilterCoefficients coefficient;
	// Note: this is valid only when corner frequency is less than nyquist / 2.
	float realPoleZ = getRealPoleZ(cornerFrequency, sampleRate);

	// Note: this is a zero at DC
	coefficient[0] = 0.5f * (1 + realPoleZ);
	coefficient[1] = -coefficient[0];
	coefficient[2] = 0.0f;
	coefficient[3] = -realPoleZ;
	coefficient[4] = 0.0f;
	return std::make_shared<HapticBiquadFilter>(
	channelCount, cascadeFirstOrderFilters(coefficient, coefficient));
	}

	std::shared_ptr<HapticBiquadFilter> createBPF(const float ringingFrequency,
	const float q,
	const float sampleRate,
	const size_t channelCount) {
	BiquadFilterCoefficients coefficient = bpfCoefs(ringingFrequency, q, sampleRate);
	return std::make_shared<HapticBiquadFilter>(channelCount, coefficient);
	}

	std::shared_ptr<HapticBiquadFilter> createBSF(const float ringingFrequency,
	const float zq,
	const float pq,
	const float sampleRate,
	const size_t channelCount) {
	BiquadFilterCoefficients coefficient = bsfCoefs(ringingFrequency, zq, pq, sampleRate);
	return std::make_shared<HapticBiquadFilter>(channelCount, coefficient);
	}

	} // namespace android::audio_effect::haptic_generator