1 /* 2 * Copyright (C) 2020 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ANALYZER_DATA_PATH_ANALYZER_H 18 #define ANALYZER_DATA_PATH_ANALYZER_H 19 20 #include <algorithm> 21 #include <cctype> 22 #include <iomanip> 23 #include <iostream> 24 #include <math.h> 25 26 #include "BaseSineAnalyzer.h" 27 #include "InfiniteRecording.h" 28 #include "LatencyAnalyzer.h" 29 30 /** 31 * Output a steady sine wave and analyze the return signal. 32 * 33 * Use a cosine transform to measure the predicted magnitude and relative phase of the 34 * looped back sine wave. 35 */ 36 class DataPathAnalyzer : public BaseSineAnalyzer { 37 public: 38 DataPathAnalyzer()39 DataPathAnalyzer() : BaseSineAnalyzer() { 40 // Add a little bit of noise to reduce blockage by speaker protection and DRC. 41 setNoiseAmplitude(0.02); 42 } 43 44 /** 45 * @param frameData contains microphone data with sine signal feedback 46 * @param channelCount 47 */ processInputFrame(const float * frameData,int)48 result_code processInputFrame(const float *frameData, int /* channelCount */) override { 49 result_code result = RESULT_OK; 50 51 float sample = frameData[getInputChannel()]; 52 mInfiniteRecording.write(sample); 53 54 if (transformSample(sample, mOutputPhase)) { 55 resetAccumulator(); 56 // Analyze magnitude and phase on every period. 57 double diff = abs(mPhaseOffset - mPreviousPhaseOffset); 58 if (diff < mPhaseTolerance) { 59 mMaxMagnitude = std::max(mMagnitude, mMaxMagnitude); 60 } 61 mPreviousPhaseOffset = mPhaseOffset; 62 } 63 return result; 64 } 65 analyze()66 std::string analyze() override { 67 std::stringstream report; 68 report << "DataPathAnalyzer ------------------\n"; 69 report << LOOPBACK_RESULT_TAG "sine.magnitude = " << std::setw(8) 70 << mMagnitude << "\n"; 71 report << LOOPBACK_RESULT_TAG "frames.accumulated = " << std::setw(8) 72 << mFramesAccumulated << "\n"; 73 report << LOOPBACK_RESULT_TAG "sine.period = " << std::setw(8) 74 << mSinePeriod << "\n"; 75 return report.str(); 76 } 77 reset()78 void reset() override { 79 BaseSineAnalyzer::reset(); 80 mPreviousPhaseOffset = 999.0; // Arbitrary high offset to prevent early lock. 81 mMaxMagnitude = 0.0; 82 } 83 getMaxMagnitude()84 double getMaxMagnitude() { 85 return mMaxMagnitude; 86 } 87 88 private: 89 double mPreviousPhaseOffset = 0.0; 90 double mPhaseTolerance = 2 * M_PI / 48; 91 double mMaxMagnitude = 0.0; 92 }; 93 #endif // ANALYZER_DATA_PATH_ANALYZER_H 94