OboeTester: factor out analyzer

So we can use it in CTS or other projects.
diff --git a/apps/OboeTester/app/src/main/cpp/FullDuplexAnalyzer.h b/apps/OboeTester/app/src/main/cpp/FullDuplexAnalyzer.h
index b323ffb..ee12fc1 100644
--- a/apps/OboeTester/app/src/main/cpp/FullDuplexAnalyzer.h
+++ b/apps/OboeTester/app/src/main/cpp/FullDuplexAnalyzer.h
@@ -22,7 +22,7 @@
 
 #include "oboe/Oboe.h"
 #include "FullDuplexStream.h"
-#include "LatencyAnalyzer.h"
+#include "analyzer/LatencyAnalyzer.h"
 #include "MultiChannelRecording.h"
 
 class FullDuplexAnalyzer : public FullDuplexStream {
diff --git a/apps/OboeTester/app/src/main/cpp/FullDuplexGlitches.h b/apps/OboeTester/app/src/main/cpp/FullDuplexGlitches.h
index 68e3688..1046e04 100644
--- a/apps/OboeTester/app/src/main/cpp/FullDuplexGlitches.h
+++ b/apps/OboeTester/app/src/main/cpp/FullDuplexGlitches.h
@@ -22,6 +22,7 @@
 
 #include "oboe/Oboe.h"
 #include "FullDuplexAnalyzer.h"
+#include "analyzer/GlitchAnalyzer.h"
 
 class FullDuplexGlitches : public FullDuplexAnalyzer {
 public:
diff --git a/apps/OboeTester/app/src/main/cpp/InputStreamCallbackAnalyzer.h b/apps/OboeTester/app/src/main/cpp/InputStreamCallbackAnalyzer.h
index 4bc6a80..42ffbfb 100644
--- a/apps/OboeTester/app/src/main/cpp/InputStreamCallbackAnalyzer.h
+++ b/apps/OboeTester/app/src/main/cpp/InputStreamCallbackAnalyzer.h
@@ -24,7 +24,7 @@
 // TODO #include "flowgraph/FlowGraph.h"
 #include "oboe/Oboe.h"
 #include "MultiChannelRecording.h"
-#include "PeakDetector.h"
+#include "analyzer/PeakDetector.h"
 
 constexpr int kMaxInputChannels = 8;
 
diff --git a/apps/OboeTester/app/src/main/cpp/LatencyAnalyzer.h b/apps/OboeTester/app/src/main/cpp/LatencyAnalyzer.h
deleted file mode 100644
index 343629a..0000000
--- a/apps/OboeTester/app/src/main/cpp/LatencyAnalyzer.h
+++ /dev/null
@@ -1,1126 +0,0 @@
-/*
- * Copyright (C) 2017 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.
- */
-
-/**
- * Tools for measuring latency and for detecting glitches.
- * These classes are pure math and can be used with any audio system.
- */
-
-#ifndef OBOETESTER_LATENCY_ANALYSER_H
-#define OBOETESTER_LATENCY_ANALYSER_H
-
-#include <algorithm>
-#include <assert.h>
-#include <cctype>
-#include <math.h>
-#include <memory>
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <vector>
-
-#include "RandomPulseGenerator.h"
-
-#define LOOPBACK_RESULT_TAG  "RESULT: "
-
-constexpr int32_t kDefaultSampleRate = 48000;
-constexpr int32_t kMillisPerSecond   = 1000;
-
-constexpr int32_t kMaxLatencyMillis  = 700;  // arbitrary and generous
-constexpr double  kMinimumConfidence = 0.2;
-
-class PseudoRandom {
-public:
-    PseudoRandom() {}
-    PseudoRandom(int64_t seed)
-            :    mSeed(seed)
-    {}
-
-    /**
-     * Returns the next random double from -1.0 to 1.0
-     *
-     * @return value from -1.0 to 1.0
-     */
-     double nextRandomDouble() {
-        return nextRandomInteger() * (0.5 / (((int32_t)1) << 30));
-    }
-
-    /** Calculate random 32 bit number using linear-congruential method.
-     */
-    int32_t nextRandomInteger() {
-#if __has_builtin(__builtin_mul_overflow) && __has_builtin(__builtin_add_overflow)
-        int64_t prod;
-        // Use values for 64-bit sequence from MMIX by Donald Knuth.
-        __builtin_mul_overflow(mSeed, (int64_t)6364136223846793005, &prod);
-        __builtin_add_overflow(prod, (int64_t)1442695040888963407, &mSeed);
-#else
-        mSeed = (mSeed * (int64_t)6364136223846793005) + (int64_t)1442695040888963407;
-#endif
-        return (int32_t) (mSeed >> 32); // The higher bits have a longer sequence.
-    }
-
-private:
-    int64_t mSeed = 99887766;
-};
-
-class PeakFollower {
-public:
-    float process(float input) {
-        mPrevious *= kDecayCoefficient;
-        const float positive = abs(input);
-        if (positive > mPrevious) {
-            mPrevious = positive;
-        }
-        return mPrevious;
-    }
-
-    float get() {
-        return mPrevious;
-    }
-
-private:
-    static constexpr float kDecayCoefficient = 0.99f;
-    float mPrevious = 0.0f;
-};
-
-typedef struct LatencyReport_s {
-    int32_t latencyInFrames = 0.0;
-    double confidence = 0.0;
-
-    void reset() {
-        latencyInFrames = 0;
-        confidence = 0.0;
-    }
-} LatencyReport;
-
-// Calculate a normalized cross correlation.
-static double calculateNormalizedCorrelation(const float *a,
-                                             const float *b,
-                                             int windowSize)
-{
-    double correlation = 0.0;
-    double sumProducts = 0.0;
-    double sumSquares = 0.0;
-
-    // Correlate a against b.
-    for (int i = 0; i < windowSize; i++) {
-        float s1 = a[i];
-        float s2 = b[i];
-        // Use a normalized cross-correlation.
-        sumProducts += s1 * s2;
-        sumSquares += ((s1 * s1) + (s2 * s2));
-    }
-
-    if (sumSquares >= 1.0e-9) {
-        correlation = (float) (2.0 * sumProducts / sumSquares);
-    }
-    return correlation;
-}
-
-static double calculateRootMeanSquare(float *data, int32_t numSamples) {
-    double sum = 0.0;
-    for (int32_t i = 0; i < numSamples; i++) {
-        float sample = data[i];
-        sum += sample * sample;
-    }
-    return sqrt(sum / numSamples);
-}
-
-/**
- * Monophonic recording with processing.
- */
-class AudioRecording
-{
-public:
-    AudioRecording() {
-    }
-    ~AudioRecording() {
-        delete[] mData;
-    }
-
-    void allocate(int maxFrames) {
-        delete[] mData;
-        mData = new float[maxFrames];
-        mMaxFrames = maxFrames;
-    }
-
-    // Write SHORT data from the first channel.
-    int32_t write(int16_t *inputData, int32_t inputChannelCount, int32_t numFrames) {
-        // stop at end of buffer
-        if ((mFrameCounter + numFrames) > mMaxFrames) {
-            numFrames = mMaxFrames - mFrameCounter;
-        }
-        for (int i = 0; i < numFrames; i++) {
-            mData[mFrameCounter++] = inputData[i * inputChannelCount] * (1.0f / 32768);
-        }
-        return numFrames;
-    }
-
-    // Write FLOAT data from the first channel.
-    int32_t write(float *inputData, int32_t inputChannelCount, int32_t numFrames) {
-        // stop at end of buffer
-        if ((mFrameCounter + numFrames) > mMaxFrames) {
-            numFrames = mMaxFrames - mFrameCounter;
-        }
-        for (int i = 0; i < numFrames; i++) {
-            mData[mFrameCounter++] = inputData[i * inputChannelCount];
-        }
-        return numFrames;
-    }
-
-    // Write FLOAT data from the first channel.
-    int32_t write(float sample) {
-        // stop at end of buffer
-        if (mFrameCounter < mMaxFrames) {
-            mData[mFrameCounter++] = sample;
-        }
-        return 1;
-    }
-
-    void clear() {
-        mFrameCounter = 0;
-    }
-    int32_t size() {
-        return mFrameCounter;
-    }
-
-    bool isFull() {
-        return mFrameCounter >= mMaxFrames;
-    }
-
-    float *getData() {
-        return mData;
-    }
-
-    void setSampleRate(int32_t sampleRate) {
-        mSampleRate = sampleRate;
-    }
-
-    int32_t getSampleRate() {
-        return mSampleRate;
-    }
-
-/*
-    int save(const char *fileName, bool writeShorts = true) {
-        SNDFILE *sndFile = nullptr;
-        int written = 0;
-        SF_INFO info = {
-                .frames = mFrameCounter,
-                .samplerate = mSampleRate,
-                .channels = 1,
-                .format = SF_FORMAT_WAV | (writeShorts ? SF_FORMAT_PCM_16 : SF_FORMAT_FLOAT)
-        };
-
-        sndFile = sf_open(fileName, SFM_WRITE, &info);
-        if (sndFile == nullptr) {
-            LOGD("AudioRecording::save(%s) failed to open file\n", fileName);
-            return -errno;
-        }
-
-        written = sf_writef_float(sndFile, mData, mFrameCounter);
-
-        sf_close(sndFile);
-        return written;
-    }
-
-    int load(const char *fileName) {
-        SNDFILE *sndFile = nullptr;
-        SF_INFO info;
-
-        sndFile = sf_open(fileName, SFM_READ, &info);
-        if (sndFile == nullptr) {
-            LOGD("AudioRecording::load(%s) failed to open file\n", fileName);
-            return -errno;
-        }
-
-        assert(info.channels == 1);
-        assert(info.format == SF_FORMAT_FLOAT);
-
-        setSampleRate(info.samplerate);
-        allocate(info.frames);
-        mFrameCounter = sf_readf_float(sndFile, mData, info.frames);
-
-        sf_close(sndFile);
-        return mFrameCounter;
-    }
-*/
-    /**
-     * Square the samples so they are all positive and so the peaks are emphasized.
-     */
-    void square() {
-        for (int i = 0; i < mFrameCounter; i++) {
-            const float sample = mData[i];
-            mData[i] = sample * sample;
-        }
-    }
-
-    /**
-     * Amplify a signal so that the peak matches the specified target.
-     *
-     * @param target final max value
-     * @return gain applied to signal
-     */
-    float normalize(float target) {
-        float maxValue = 1.0e-9f;
-        for (int i = 0; i < mFrameCounter; i++) {
-            maxValue = std::max(maxValue, abs(mData[i]));
-        }
-        float gain = target / maxValue;
-        for (int i = 0; i < mFrameCounter; i++) {
-            mData[i] *= gain;
-        }
-        return gain;
-    }
-
-private:
-    float        *mData = nullptr;
-    int32_t       mFrameCounter = 0;
-    int32_t       mMaxFrames = 0;
-    int32_t       mSampleRate = kDefaultSampleRate; // common default
-};
-
-static int measureLatencyFromPulse(AudioRecording &recorded,
-                                   AudioRecording &pulse,
-                                   int32_t framesPerEncodedBit,
-                                   LatencyReport *report) {
-
-    report->latencyInFrames = 0;
-    report->confidence = 0.0;
-
-    int numCorrelations = recorded.size() - pulse.size();
-    if (numCorrelations < 10) {
-        LOGE("%s() recording too small = %d frames", __func__, recorded.size());
-        return -1;
-    }
-    std::unique_ptr<float[]> correlations= std::make_unique<float[]>(numCorrelations);
-
-    // Correlate pulse against the recorded data.
-    for (int i = 0; i < numCorrelations; i++) {
-        float correlation = (float) calculateNormalizedCorrelation(&recorded.getData()[i],
-                                                                   &pulse.getData()[0],
-                                                                   pulse.size());
-        correlations[i] = correlation;
-    }
-
-    // Find highest peak in correlation array.
-    float peakCorrelation = 0.0;
-    int peakIndex = -1;
-    for (int i = 0; i < numCorrelations; i++) {
-        float value = abs(correlations[i]);
-        if (value > peakCorrelation) {
-            peakCorrelation = value;
-            peakIndex = i;
-        }
-    }
-    if (peakIndex < 0) {
-        LOGE("%s() no signal for correlation", __func__);
-        return -2;
-    }
-
-    report->latencyInFrames = peakIndex;
-    report->confidence = peakCorrelation;
-
-    return 0;
-}
-
-// ====================================================================================
-class LoopbackProcessor {
-public:
-    virtual ~LoopbackProcessor() = default;
-
-    // Note that these values must match the switch in RoundTripLatencyActivity.h
-    enum result_code {
-        RESULT_OK = 0,
-        ERROR_NOISY = -99,
-        ERROR_VOLUME_TOO_LOW,
-        ERROR_VOLUME_TOO_HIGH,
-        ERROR_CONFIDENCE,
-        ERROR_INVALID_STATE,
-        ERROR_GLITCHES,
-        ERROR_NO_LOCK
-    };
-
-    virtual void onStartTest() {
-        reset();
-    }
-
-    virtual void reset() {
-        mResult = 0;
-        mResetCount++;
-    }
-
-    virtual result_code processInputFrame(float *frameData, int channelCount) = 0;
-    virtual result_code processOutputFrame(float *frameData, int channelCount) = 0;
-
-    void process(float *inputData, int inputChannelCount, int numInputFrames,
-                        float *outputData, int outputChannelCount, int numOutputFrames) {
-        int numBoth = std::min(numInputFrames, numOutputFrames);
-        // Process one frame at a time.
-        for (int i = 0; i < numBoth; i++) {
-            processInputFrame(inputData, inputChannelCount);
-            inputData += inputChannelCount;
-            processOutputFrame(outputData, outputChannelCount);
-            outputData += outputChannelCount;
-        }
-        // If there is more input than output.
-        for (int i = numBoth; i < numInputFrames; i++) {
-            processInputFrame(inputData, inputChannelCount);
-            inputData += inputChannelCount;
-        }
-        // If there is more output than input.
-        for (int i = numBoth; i < numOutputFrames; i++) {
-            processOutputFrame(outputData, outputChannelCount);
-            outputData += outputChannelCount;
-        }
-    }
-
-    virtual void analyze() = 0;
-
-    virtual void printStatus() {};
-
-    int32_t getResult() {
-        return mResult;
-    }
-
-    void setResult(int32_t result) {
-        mResult = result;
-    }
-
-    virtual bool isDone() {
-        return false;
-    }
-
-    virtual int save(const char *fileName) {
-        (void) fileName;
-        return -1;
-    }
-
-    virtual int load(const char *fileName) {
-        (void) fileName;
-        return -1;
-    }
-
-    virtual void setSampleRate(int32_t sampleRate) {
-        mSampleRate = sampleRate;
-    }
-
-    int32_t getSampleRate() {
-        return mSampleRate;
-    }
-
-    int32_t getResetCount() {
-        return mResetCount;
-    }
-
-    /** Called when not enough input frames could be read after synchronization.
-     */
-    virtual void onInsufficientRead() {
-        reset();
-    }
-
-protected:
-    int32_t   mResetCount = 0;
-
-private:
-    int32_t mSampleRate = kDefaultSampleRate;
-    int32_t mResult = 0;
-};
-
-/*
-class PeakAnalyzer {
-public:
-    float process(float input) {
-        float output = mPrevious * mDecay;
-        if (input > output) {
-            output = input;
-        }
-        mPrevious = output;
-        return output;
-    }
-
-private:
-    float  mDecay = 0.99f;
-    float  mPrevious = 0.0f;
-};
-*/
-
-class LatencyAnalyzer : public LoopbackProcessor {
-public:
-
-    LatencyAnalyzer() : LoopbackProcessor() {}
-    virtual ~LatencyAnalyzer() = default;
-
-    virtual int32_t getProgress() = 0;
-
-    virtual int getState() = 0;
-
-    // @return latency in frames
-    virtual int32_t getMeasuredLatency() = 0;
-
-    virtual double getMeasuredConfidence() = 0;
-
-    virtual double getBackgroundRMS() = 0;
-
-    virtual double getSignalRMS() = 0;
-
-};
-
-// ====================================================================================
-/**
- * Measure latency given a loopback stream data.
- * Use an encoded bit train as the sound source because it
- * has an unambiguous correlation value.
- * Uses a state machine to cycle through various stages.
- *
- */
-class PulseLatencyAnalyzer : public LatencyAnalyzer {
-public:
-
-    PulseLatencyAnalyzer() : LatencyAnalyzer() {
-        int32_t maxLatencyFrames = getSampleRate() * kMaxLatencyMillis / kMillisPerSecond;
-        int32_t numPulseBits = getSampleRate() * kPulseLengthMillis
-                / (kFramesPerEncodedBit * kMillisPerSecond);
-        int32_t  pulseLength = numPulseBits * kFramesPerEncodedBit;
-        mFramesToRecord = pulseLength + maxLatencyFrames;
-        LOGD("PulseLatencyAnalyzer: allocate recording with %d frames", mFramesToRecord);
-        mAudioRecording.allocate(mFramesToRecord);
-        mAudioRecording.setSampleRate(getSampleRate());
-        generateRandomPulse(pulseLength);
-    }
-
-    void generateRandomPulse(int32_t pulseLength) {
-        mPulse.allocate(pulseLength);
-        RandomPulseGenerator pulser(kFramesPerEncodedBit);
-        for (int i = 0; i < pulseLength; i++) {
-            mPulse.write(pulser.nextFloat());
-        }
-    }
-
-    int getState() override {
-        return mState;
-    }
-
-    void setSampleRate(int32_t sampleRate) override {
-        LoopbackProcessor::setSampleRate(sampleRate);
-        mAudioRecording.setSampleRate(sampleRate);
-    }
-
-    void reset() override {
-        LoopbackProcessor::reset();
-        mDownCounter = getSampleRate() / 2;
-        mLoopCounter = 0;
-
-        mPulseCursor = 0;
-        mBackgroundSumSquare = 0.0f;
-        mBackgroundSumCount = 0;
-        mBackgroundRMS = 0.0f;
-        mSignalRMS = 0.0f;
-
-        LOGD("state reset to STATE_MEASURE_BACKGROUND");
-        mState = STATE_MEASURE_BACKGROUND;
-        mAudioRecording.clear();
-        mLatencyReport.reset();
-    }
-
-    bool hasEnoughData() {
-        return mAudioRecording.isFull();
-    }
-
-    bool isDone() override {
-        return mState == STATE_DONE;
-    }
-
-    int32_t getProgress() override {
-        return mAudioRecording.size();
-    }
-
-    void analyze() override {
-        LOGD("PulseLatencyAnalyzer ---------------");
-        LOGD(LOOPBACK_RESULT_TAG "test.state             = %8d", mState);
-        LOGD(LOOPBACK_RESULT_TAG "test.state.name        = %8s", convertStateToText(mState));
-        LOGD(LOOPBACK_RESULT_TAG "background.rms         = %8f", mBackgroundRMS);
-
-        int32_t newResult = RESULT_OK;
-        if (mState != STATE_GOT_DATA) {
-            LOGD("WARNING - Bad state. Check volume on device.");
-            // setResult(ERROR_INVALID_STATE);
-        } else {
-            LOGD("Please wait several seconds for cross-correlation to complete.");
-            float gain = mAudioRecording.normalize(1.0f);
-            measureLatencyFromPulse(mAudioRecording,
-                                    mPulse,
-                                    kFramesPerEncodedBit,
-                                    &mLatencyReport);
-
-            if (mLatencyReport.confidence < kMinimumConfidence) {
-                LOGD("   ERROR - confidence too low!");
-                newResult = ERROR_CONFIDENCE;
-            } else {
-                mSignalRMS = calculateRootMeanSquare(
-                        &mAudioRecording.getData()[mLatencyReport.latencyInFrames], mPulse.size())
-                                / gain;
-            }
-#if OBOE_ENABLE_LOGGING
-            double latencyMillis = kMillisPerSecond * (double) mLatencyReport.latencyInFrames
-                                   / getSampleRate();
-#endif
-            LOGD(LOOPBACK_RESULT_TAG "latency.frames         = %8d",
-                   mLatencyReport.latencyInFrames);
-            LOGD(LOOPBACK_RESULT_TAG "latency.msec           = %8.2f",
-                   latencyMillis);
-            LOGD(LOOPBACK_RESULT_TAG "latency.confidence     = %8.6f",
-                   mLatencyReport.confidence);
-        }
-        mState = STATE_DONE;
-        if (getResult() == RESULT_OK) {
-            setResult(newResult);
-        }
-    }
-
-    int32_t getMeasuredLatency() override {
-        return mLatencyReport.latencyInFrames;
-    }
-
-    double getMeasuredConfidence() override {
-        return mLatencyReport.confidence;
-    }
-
-    double getBackgroundRMS() override {
-        return mBackgroundRMS;
-    }
-
-    double getSignalRMS() override {
-        return mSignalRMS;
-    }
-
-    void printStatus() override {
-        LOGD("st = %d", mState);
-    }
-
-    result_code processInputFrame(float *frameData, int channelCount) override {
-        echo_state nextState = mState;
-        mLoopCounter++;
-
-        switch (mState) {
-            case STATE_MEASURE_BACKGROUND:
-                // Measure background RMS on channel 0
-                mBackgroundSumSquare += frameData[0] * frameData[0];
-                mBackgroundSumCount++;
-                mDownCounter--;
-                if (mDownCounter <= 0) {
-                    mBackgroundRMS = sqrtf(mBackgroundSumSquare / mBackgroundSumCount);
-                    nextState = STATE_IN_PULSE;
-                    mPulseCursor = 0;
-                    LOGD("LatencyAnalyzer state => STATE_SENDING_PULSE");
-                }
-                break;
-
-            case STATE_IN_PULSE:
-                // Record input until the mAudioRecording is full.
-                mAudioRecording.write(frameData, channelCount, 1);
-                if (hasEnoughData()) {
-                    LOGD("LatencyAnalyzer state => STATE_GOT_DATA");
-                    nextState = STATE_GOT_DATA;
-                }
-                break;
-
-            case STATE_GOT_DATA:
-            case STATE_DONE:
-            default:
-                break;
-        }
-
-        mState = nextState;
-        return RESULT_OK;
-    }
-
-    result_code processOutputFrame(float *frameData, int channelCount) override {
-        switch (mState) {
-            case STATE_IN_PULSE:
-                if (mPulseCursor < mPulse.size()) {
-                    float pulseSample = mPulse.getData()[mPulseCursor++];
-                    for (int i = 0; i < channelCount; i++) {
-                        frameData[i] = pulseSample;
-                    }
-                } else {
-                    for (int i = 0; i < channelCount; i++) {
-                        frameData[i] = 0;
-                    }
-                }
-                break;
-
-            case STATE_MEASURE_BACKGROUND:
-            case STATE_GOT_DATA:
-            case STATE_DONE:
-            default:
-                for (int i = 0; i < channelCount; i++) {
-                    frameData[i] = 0.0f; // silence
-                }
-                break;
-        }
-
-        return RESULT_OK;
-    }
-
-private:
-
-    enum echo_state {
-        STATE_MEASURE_BACKGROUND,
-        STATE_IN_PULSE,
-        STATE_GOT_DATA, // must match RoundTripLatencyActivity.java
-        STATE_DONE,
-    };
-
-    const char *convertStateToText(echo_state state) {
-        const char *result = "Unknown";
-        switch(state) {
-            case STATE_MEASURE_BACKGROUND:
-                result = "INIT";
-                break;
-            case STATE_IN_PULSE:
-                result = "PULSE";
-                break;
-            case STATE_GOT_DATA:
-                result = "GOT_DATA";
-                break;
-            case STATE_DONE:
-                result = "DONE";
-                break;
-        }
-        return result;
-    }
-
-    int32_t         mDownCounter = 500;
-    int32_t         mLoopCounter = 0;
-    echo_state      mState = STATE_MEASURE_BACKGROUND;
-
-    static constexpr int32_t kFramesPerEncodedBit = 8; // multiple of 2
-    static constexpr int32_t kPulseLengthMillis = 500;
-
-    AudioRecording     mPulse;
-    int32_t            mPulseCursor = 0;
-
-    float              mBackgroundSumSquare = 0.0f;
-    int32_t            mBackgroundSumCount = 0;
-    float              mBackgroundRMS = 0.0f;
-    float              mSignalRMS = 0.0f;
-    int32_t            mFramesToRecord = 0;
-
-    AudioRecording     mAudioRecording; // contains only the input after starting the pulse
-    LatencyReport      mLatencyReport;
-};
-
-// ====================================================================================
-/**
- * Output a steady sinewave and analyze the return signal.
- *
- * Use a cosine transform to measure the predicted magnitude and relative phase of the
- * looped back sine wave. Then generate a predicted signal and compare with the actual signal.
- */
-class GlitchAnalyzer : public LoopbackProcessor {
-public:
-
-    int32_t getState() {
-        return mState;
-    }
-
-    float getPeakAmplitude() {
-        return mPeakFollower.get();
-    }
-
-    float getTolerance() {
-        return mTolerance;
-    }
-
-    void setTolerance(float tolerance) {
-        mTolerance = tolerance;
-        mScaledTolerance = mMagnitude * mTolerance;
-    }
-
-    void setMagnitude(double magnitude) {
-        mMagnitude = magnitude;
-        mScaledTolerance = mMagnitude * mTolerance;
-    }
-
-    int32_t getGlitchCount() {
-        return mGlitchCount;
-    }
-
-    int32_t getStateFrameCount(int state) {
-        return mStateFrameCounters[state];
-    }
-
-    double getSignalToNoiseDB() {
-        static const double threshold = 1.0e-14;
-        if (mMeanSquareSignal < threshold || mMeanSquareNoise < threshold) {
-            return 0.0;
-        } else {
-            double signalToNoise = mMeanSquareSignal / mMeanSquareNoise; // power ratio
-            double signalToNoiseDB = 10.0 * log(signalToNoise);
-            if (signalToNoiseDB < MIN_SNRATIO_DB) {
-                LOGD("ERROR - signal to noise ratio is too low! < %d dB. Adjust volume.",
-                     MIN_SNRATIO_DB);
-                setResult(ERROR_VOLUME_TOO_LOW);
-            }
-            return signalToNoiseDB;
-        }
-    }
-
-    void analyze() override {
-        LOGD("GlitchAnalyzer ------------------");
-        LOGD(LOOPBACK_RESULT_TAG "peak.amplitude     = %8f", getPeakAmplitude());
-        LOGD(LOOPBACK_RESULT_TAG "sine.magnitude     = %8f", mMagnitude);
-        LOGD(LOOPBACK_RESULT_TAG "rms.noise          = %8f", mMeanSquareNoise);
-        LOGD(LOOPBACK_RESULT_TAG "signal.to.noise.db = %8.2f", getSignalToNoiseDB());
-        LOGD(LOOPBACK_RESULT_TAG "frames.accumulated = %8d", mFramesAccumulated);
-        LOGD(LOOPBACK_RESULT_TAG "sine.period        = %8d", mSinePeriod);
-        LOGD(LOOPBACK_RESULT_TAG "test.state         = %8d", mState);
-        LOGD(LOOPBACK_RESULT_TAG "frame.count        = %8d", mFrameCounter);
-        // Did we ever get a lock?
-        bool gotLock = (mState == STATE_LOCKED) || (mGlitchCount > 0);
-        if (!gotLock) {
-            LOGD("ERROR - failed to lock on reference sine tone");
-            setResult(ERROR_NO_LOCK);
-        } else {
-            // Only print if meaningful.
-            LOGD(LOOPBACK_RESULT_TAG "glitch.count       = %8d", mGlitchCount);
-            LOGD(LOOPBACK_RESULT_TAG "max.glitch         = %8f", mMaxGlitchDelta);
-            if (mGlitchCount > 0) {
-                LOGD("ERROR - number of glitches > 0");
-                setResult(ERROR_GLITCHES);
-            }
-        }
-    }
-
-    void printStatus() override {
-        LOGD("st = %d, #gl = %3d,", mState, mGlitchCount);
-    }
-
-    double calculateMagnitude(double *phasePtr = NULL) {
-        if (mFramesAccumulated == 0) {
-            return 0.0;
-        }
-        double sinMean = mSinAccumulator / mFramesAccumulated;
-        double cosMean = mCosAccumulator / mFramesAccumulated;
-        double magnitude = 2.0 * sqrt( (sinMean * sinMean) + (cosMean * cosMean ));
-        if( phasePtr != NULL )
-        {
-            double phase = M_PI_2 - atan2( sinMean, cosMean );
-            *phasePtr = phase;
-        }
-        return magnitude;
-    }
-
-    /**
-     * @param frameData contains microphone data with sine signal feedback
-     * @param channelCount
-     */
-    result_code processInputFrame(float *frameData, int channelCount) override {
-        result_code result = RESULT_OK;
-
-        float sample = frameData[0];
-        float peak = mPeakFollower.process(sample);
-
-        // Force a periodic glitch!
-        if (mForceGlitchDuration > 0) {
-            if (mForceGlitchCounter == 0) {
-                LOGE("%s: force a glitch!!", __func__);
-                mForceGlitchCounter = getSampleRate();
-            } else if (mForceGlitchCounter <= mForceGlitchDuration) {
-                sample += (sample > 0.0) ? -0.5f : 0.5f;
-            }
-            --mForceGlitchCounter;
-        }
-
-        mStateFrameCounters[mState]++; // count how many frames we are in each state
-
-        switch (mState) {
-            case STATE_IDLE:
-                mDownCounter--;
-                if (mDownCounter <= 0) {
-                    mState = STATE_IMMUNE;
-                    mDownCounter = IMMUNE_FRAME_COUNT;
-                    mInputPhase = 0.0; // prevent spike at start
-                    mOutputPhase = 0.0;
-                }
-                break;
-
-            case STATE_IMMUNE:
-                mDownCounter--;
-                if (mDownCounter <= 0) {
-                    mState = STATE_WAITING_FOR_SIGNAL;
-                }
-                break;
-
-            case STATE_WAITING_FOR_SIGNAL:
-                if (peak > mThreshold) {
-                    mState = STATE_WAITING_FOR_LOCK;
-                    //LOGD("%5d: switch to STATE_WAITING_FOR_LOCK", mFrameCounter);
-                    resetAccumulator();
-                }
-                break;
-
-            case STATE_WAITING_FOR_LOCK:
-                mSinAccumulator += sample * sinf(mInputPhase);
-                mCosAccumulator += sample * cosf(mInputPhase);
-                mFramesAccumulated++;
-                // Must be a multiple of the period or the calculation will not be accurate.
-                if (mFramesAccumulated == mSinePeriod * PERIODS_NEEDED_FOR_LOCK) {
-                    double phaseOffset = 0.0;
-                    setMagnitude(calculateMagnitude(&phaseOffset));
-//                    LOGD("%s() mag = %f, offset = %f, prev = %f",
-//                            __func__, mMagnitude, mPhaseOffset, mPreviousPhaseOffset);
-                    if (mMagnitude > mThreshold) {
-                        if (abs(phaseOffset) < kMaxPhaseError) {
-                            mState = STATE_LOCKED;
-//                            LOGD("%5d: switch to STATE_LOCKED", mFrameCounter);
-                        }
-                        // Adjust mInputPhase to match measured phase
-                        mInputPhase += phaseOffset;
-                    }
-                    resetAccumulator();
-                }
-                incrementInputPhase();
-                break;
-
-            case STATE_LOCKED: {
-                // Predict next sine value
-                float predicted = sinf(mInputPhase) * mMagnitude;
-                float diff = predicted - sample;
-                float absDiff = fabs(diff);
-                mMaxGlitchDelta = std::max(mMaxGlitchDelta, absDiff);
-                if (absDiff > mScaledTolerance) {
-                    result = ERROR_GLITCHES;
-                    onGlitchStart();
-//                    LOGI("diff glitch detected, absDiff = %g", absDiff);
-                } else {
-                    mSumSquareSignal += predicted * predicted;
-                    mSumSquareNoise += diff * diff;
-                    // Track incoming signal and slowly adjust magnitude to account
-                    // for drift in the DRC or AGC.
-                    mSinAccumulator += sample * sinf(mInputPhase);
-                    mCosAccumulator += sample * cosf(mInputPhase);
-                    mFramesAccumulated++;
-                    // Must be a multiple of the period or the calculation will not be accurate.
-                    if (mFramesAccumulated == mSinePeriod) {
-                        const double coefficient = 0.1;
-                        double phaseOffset = 0.0;
-                        double magnitude = calculateMagnitude(&phaseOffset);
-                        // One pole averaging filter.
-                        setMagnitude((mMagnitude * (1.0 - coefficient)) + (magnitude * coefficient));
-
-                        mMeanSquareNoise = mSumSquareNoise * mInverseSinePeriod;
-                        mMeanSquareSignal = mSumSquareSignal * mInverseSinePeriod;
-                        resetAccumulator();
-
-                        if (abs(phaseOffset) > kMaxPhaseError) {
-                            result = ERROR_GLITCHES;
-                            onGlitchStart();
-                            LOGD("phase glitch detected, phaseOffset = %g", phaseOffset);
-                        } else if (mMagnitude < mThreshold) {
-                            result = ERROR_GLITCHES;
-                            onGlitchStart();
-                            LOGD("magnitude glitch detected, mMagnitude = %g", mMagnitude);
-                        }
-                    }
-                }
-                incrementInputPhase();
-            } break;
-
-            case STATE_GLITCHING: {
-                // Predict next sine value
-                mGlitchLength++;
-                float predicted = sinf(mInputPhase) * mMagnitude;
-                float diff = predicted - sample;
-                float absDiff = fabs(diff);
-                mMaxGlitchDelta = std::max(mMaxGlitchDelta, absDiff);
-                if (absDiff < mScaledTolerance) { // close enough?
-                    // If we get a full sine period of non-glitch samples in a row then consider the glitch over.
-                    // We don't want to just consider a zero crossing the end of a glitch.
-                    if (mNonGlitchCount++ > mSinePeriod) {
-                        onGlitchEnd();
-                    }
-                } else {
-                    mNonGlitchCount = 0;
-                    if (mGlitchLength > (4 * mSinePeriod)) {
-                       relock();
-                    }
-                }
-                incrementInputPhase();
-            } break;
-
-            case NUM_STATES: // not a real state
-                break;
-        }
-
-        mFrameCounter++;
-
-        return result;
-    }
-
-    // advance and wrap phase
-    void incrementInputPhase() {
-        mInputPhase += mPhaseIncrement;
-        if (mInputPhase > M_PI) {
-            mInputPhase -= (2.0 * M_PI);
-        }
-    }
-
-    // advance and wrap phase
-    void incrementOutputPhase() {
-        mOutputPhase += mPhaseIncrement;
-        if (mOutputPhase > M_PI) {
-            mOutputPhase -= (2.0 * M_PI);
-        }
-    }
-
-    /**
-     * @param frameData upon return, contains the reference sine wave
-     * @param channelCount
-     */
-    result_code processOutputFrame(float *frameData, int channelCount) override {
-        float output = 0.0f;
-        // Output sine wave so we can measure it.
-        if (mState != STATE_IDLE) {
-            float sinOut = sinf(mOutputPhase);
-            incrementOutputPhase();
-            output = (sinOut * mOutputAmplitude)
-                     + (mWhiteNoise.nextRandomDouble() * kNoiseAmplitude);
-            // LOGD("%5d: sin(%f) = %f, %f", i, mPhase, sinOut,  mPhaseIncrement);
-        }
-        frameData[0] = output;
-        for (int i = 1; i < channelCount; i++) {
-            frameData[i] = 0.0f;
-        }
-        return RESULT_OK;
-    }
-
-    void onGlitchStart() {
-        mGlitchCount++;
-//        LOGD("%5d: STARTED a glitch # %d", mFrameCounter, mGlitchCount);
-        mState = STATE_GLITCHING;
-        mGlitchLength = 1;
-        mNonGlitchCount = 0;
-    }
-
-    void onGlitchEnd() {
-//        LOGD("%5d: ENDED a glitch # %d, length = %d", mFrameCounter, mGlitchCount, mGlitchLength);
-        mState = STATE_LOCKED;
-        resetAccumulator();
-    }
-
-    // reset the sine wave detector
-    void resetAccumulator() {
-        mFramesAccumulated = 0;
-        mSinAccumulator = 0.0;
-        mCosAccumulator = 0.0;
-        mSumSquareSignal = 0.0;
-        mSumSquareNoise = 0.0;
-    }
-
-    void relock() {
-//        LOGD("relock: %d because of a very long %d glitch", mFrameCounter, mGlitchLength);
-        mState = STATE_WAITING_FOR_LOCK;
-        resetAccumulator();
-    }
-
-    void reset() override {
-        LoopbackProcessor::reset();
-        mState = STATE_IDLE;
-        mDownCounter = IDLE_FRAME_COUNT;
-        resetAccumulator();
-    }
-
-    void onStartTest() override {
-        LoopbackProcessor::onStartTest();
-        mSinePeriod = getSampleRate() / kTargetGlitchFrequency;
-        mOutputPhase = 0.0f;
-        mInverseSinePeriod = 1.0 / mSinePeriod;
-        mPhaseIncrement = 2.0 * M_PI * mInverseSinePeriod;
-        mGlitchCount = 0;
-        mMaxGlitchDelta = 0.0;
-        for (int i = 0; i < NUM_STATES; i++) {
-            mStateFrameCounters[i] = 0;
-        }
-    }
-
-private:
-
-    // These must match the values in GlitchActivity.java
-    enum sine_state_t {
-        STATE_IDLE,               // beginning
-        STATE_IMMUNE,             // ignoring input, waiting fo HW to settle
-        STATE_WAITING_FOR_SIGNAL, // looking for a loud signal
-        STATE_WAITING_FOR_LOCK,   // trying to lock onto the phase of the sine
-        STATE_LOCKED,             // locked on the sine wave, looking for glitches
-        STATE_GLITCHING,           // locked on the sine wave but glitching
-        NUM_STATES
-    };
-
-    enum constants {
-        // Arbitrary durations, assuming 48000 Hz
-        IDLE_FRAME_COUNT = 48 * 100,
-        IMMUNE_FRAME_COUNT = 48 * 100,
-        PERIODS_NEEDED_FOR_LOCK = 8,
-        MIN_SNRATIO_DB = 65
-    };
-
-    static constexpr float kNoiseAmplitude = 0.00; // Used to experiment with warbling caused by DRC.
-    static constexpr int kTargetGlitchFrequency = 607;
-    static constexpr double kMaxPhaseError = M_PI * 0.05;
-
-    float   mTolerance = 0.10; // scaled from 0.0 to 1.0
-    double  mThreshold = 0.005;
-    int     mSinePeriod = 1; // this will be set before use
-    double  mInverseSinePeriod = 1.0;
-
-    int32_t mStateFrameCounters[NUM_STATES];
-
-    double  mPhaseIncrement = 0.0;
-    double  mInputPhase = 0.0;
-    double  mOutputPhase = 0.0;
-    double  mMagnitude = 0.0;
-    int32_t mFramesAccumulated = 0;
-    double  mSinAccumulator = 0.0;
-    double  mCosAccumulator = 0.0;
-    float   mMaxGlitchDelta = 0.0f;
-    int32_t mGlitchCount = 0;
-    int32_t mNonGlitchCount = 0;
-    int32_t mGlitchLength = 0;
-    float   mScaledTolerance = 0.0;
-    int     mDownCounter = IDLE_FRAME_COUNT;
-    int32_t mFrameCounter = 0;
-    float   mOutputAmplitude = 0.75;
-
-    int32_t mForceGlitchDuration = 0; // if > 0 then force a glitch for debugging
-    int32_t mForceGlitchCounter = 4 * 48000; // count down and trigger at zero
-
-    // measure background noise continuously as a deviation from the expected signal
-    double  mSumSquareSignal = 0.0;
-    double  mSumSquareNoise = 0.0;
-    double  mMeanSquareSignal = 0.0;
-    double  mMeanSquareNoise = 0.0;
-
-    PeakFollower  mPeakFollower;
-
-    PseudoRandom  mWhiteNoise;
-
-    sine_state_t  mState = STATE_IDLE;
-};
-
-#undef LOOPBACK_RESULT_TAG
-
-#endif // OBOETESTER_LATENCY_ANALYSER_H
diff --git a/apps/OboeTester/app/src/main/cpp/analyzer/GlitchAnalyzer.h b/apps/OboeTester/app/src/main/cpp/analyzer/GlitchAnalyzer.h
new file mode 100644
index 0000000..1cf218c
--- /dev/null
+++ b/apps/OboeTester/app/src/main/cpp/analyzer/GlitchAnalyzer.h
@@ -0,0 +1,423 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#ifndef OBOETESTER_GLITCHANALYZER_H
+#define OBOETESTER_GLITCHANALYZER_H
+
+#include <cctype>
+
+#include "PseudoRandom.h"
+#include "LatencyAnalyzer.h"
+
+/**
+ * Output a steady sinewave and analyze the return signal.
+ *
+ * Use a cosine transform to measure the predicted magnitude and relative phase of the
+ * looped back sine wave. Then generate a predicted signal and compare with the actual signal.
+ */
+class GlitchAnalyzer : public LoopbackProcessor {
+public:
+
+    int32_t getState() {
+        return mState;
+    }
+
+    float getPeakAmplitude() {
+        return mPeakFollower.getLevel();
+    }
+
+    float getTolerance() {
+        return mTolerance;
+    }
+
+    void setTolerance(float tolerance) {
+        mTolerance = tolerance;
+        mScaledTolerance = mMagnitude * mTolerance;
+    }
+
+    void setMagnitude(double magnitude) {
+        mMagnitude = magnitude;
+        mScaledTolerance = mMagnitude * mTolerance;
+    }
+
+    int32_t getGlitchCount() {
+        return mGlitchCount;
+    }
+
+    int32_t getStateFrameCount(int state) {
+        return mStateFrameCounters[state];
+    }
+
+    double getSignalToNoiseDB() {
+        static const double threshold = 1.0e-14;
+        if (mMeanSquareSignal < threshold || mMeanSquareNoise < threshold) {
+            return 0.0;
+        } else {
+            double signalToNoise = mMeanSquareSignal / mMeanSquareNoise; // power ratio
+            double signalToNoiseDB = 10.0 * log(signalToNoise);
+            if (signalToNoiseDB < MIN_SNRATIO_DB) {
+                LOGD("ERROR - signal to noise ratio is too low! < %d dB. Adjust volume.",
+                     MIN_SNRATIO_DB);
+                setResult(ERROR_VOLUME_TOO_LOW);
+            }
+            return signalToNoiseDB;
+        }
+    }
+
+    void analyze() override {
+        LOGD("GlitchAnalyzer ------------------");
+        LOGD(LOOPBACK_RESULT_TAG "peak.amplitude     = %8f", getPeakAmplitude());
+        LOGD(LOOPBACK_RESULT_TAG "sine.magnitude     = %8f", mMagnitude);
+        LOGD(LOOPBACK_RESULT_TAG "rms.noise          = %8f", mMeanSquareNoise);
+        LOGD(LOOPBACK_RESULT_TAG "signal.to.noise.db = %8.2f", getSignalToNoiseDB());
+        LOGD(LOOPBACK_RESULT_TAG "frames.accumulated = %8d", mFramesAccumulated);
+        LOGD(LOOPBACK_RESULT_TAG "sine.period        = %8d", mSinePeriod);
+        LOGD(LOOPBACK_RESULT_TAG "test.state         = %8d", mState);
+        LOGD(LOOPBACK_RESULT_TAG "frame.count        = %8d", mFrameCounter);
+        // Did we ever get a lock?
+        bool gotLock = (mState == STATE_LOCKED) || (mGlitchCount > 0);
+        if (!gotLock) {
+            LOGD("ERROR - failed to lock on reference sine tone");
+            setResult(ERROR_NO_LOCK);
+        } else {
+            // Only print if meaningful.
+            LOGD(LOOPBACK_RESULT_TAG "glitch.count       = %8d", mGlitchCount);
+            LOGD(LOOPBACK_RESULT_TAG "max.glitch         = %8f", mMaxGlitchDelta);
+            if (mGlitchCount > 0) {
+                LOGD("ERROR - number of glitches > 0");
+                setResult(ERROR_GLITCHES);
+            }
+        }
+    }
+
+    void printStatus() override {
+        LOGD("st = %d, #gl = %3d,", mState, mGlitchCount);
+    }
+
+    double calculateMagnitude(double *phasePtr = NULL) {
+        if (mFramesAccumulated == 0) {
+            return 0.0;
+        }
+        double sinMean = mSinAccumulator / mFramesAccumulated;
+        double cosMean = mCosAccumulator / mFramesAccumulated;
+        double magnitude = 2.0 * sqrt( (sinMean * sinMean) + (cosMean * cosMean ));
+        if( phasePtr != NULL )
+        {
+            double phase = M_PI_2 - atan2( sinMean, cosMean );
+            *phasePtr = phase;
+        }
+        return magnitude;
+    }
+
+    /**
+     * @param frameData contains microphone data with sine signal feedback
+     * @param channelCount
+     */
+    result_code processInputFrame(float *frameData, int channelCount) override {
+        result_code result = RESULT_OK;
+
+        float sample = frameData[0];
+        float peak = mPeakFollower.process(sample);
+
+        // Force a periodic glitch!
+        if (mForceGlitchDuration > 0) {
+            if (mForceGlitchCounter == 0) {
+                LOGE("%s: force a glitch!!", __func__);
+                mForceGlitchCounter = getSampleRate();
+            } else if (mForceGlitchCounter <= mForceGlitchDuration) {
+                sample += (sample > 0.0) ? -0.5f : 0.5f;
+            }
+            --mForceGlitchCounter;
+        }
+
+        mStateFrameCounters[mState]++; // count how many frames we are in each state
+
+        switch (mState) {
+            case STATE_IDLE:
+                mDownCounter--;
+                if (mDownCounter <= 0) {
+                    mState = STATE_IMMUNE;
+                    mDownCounter = IMMUNE_FRAME_COUNT;
+                    mInputPhase = 0.0; // prevent spike at start
+                    mOutputPhase = 0.0;
+                }
+                break;
+
+            case STATE_IMMUNE:
+                mDownCounter--;
+                if (mDownCounter <= 0) {
+                    mState = STATE_WAITING_FOR_SIGNAL;
+                }
+                break;
+
+            case STATE_WAITING_FOR_SIGNAL:
+                if (peak > mThreshold) {
+                    mState = STATE_WAITING_FOR_LOCK;
+                    //LOGD("%5d: switch to STATE_WAITING_FOR_LOCK", mFrameCounter);
+                    resetAccumulator();
+                }
+                break;
+
+            case STATE_WAITING_FOR_LOCK:
+                mSinAccumulator += sample * sinf(mInputPhase);
+                mCosAccumulator += sample * cosf(mInputPhase);
+                mFramesAccumulated++;
+                // Must be a multiple of the period or the calculation will not be accurate.
+                if (mFramesAccumulated == mSinePeriod * PERIODS_NEEDED_FOR_LOCK) {
+                    double phaseOffset = 0.0;
+                    setMagnitude(calculateMagnitude(&phaseOffset));
+//                    LOGD("%s() mag = %f, offset = %f, prev = %f",
+//                            __func__, mMagnitude, mPhaseOffset, mPreviousPhaseOffset);
+                    if (mMagnitude > mThreshold) {
+                        if (abs(phaseOffset) < kMaxPhaseError) {
+                            mState = STATE_LOCKED;
+//                            LOGD("%5d: switch to STATE_LOCKED", mFrameCounter);
+                        }
+                        // Adjust mInputPhase to match measured phase
+                        mInputPhase += phaseOffset;
+                    }
+                    resetAccumulator();
+                }
+                incrementInputPhase();
+                break;
+
+            case STATE_LOCKED: {
+                // Predict next sine value
+                float predicted = sinf(mInputPhase) * mMagnitude;
+                float diff = predicted - sample;
+                float absDiff = fabs(diff);
+                mMaxGlitchDelta = std::max(mMaxGlitchDelta, absDiff);
+                if (absDiff > mScaledTolerance) {
+                    result = ERROR_GLITCHES;
+                    onGlitchStart();
+//                    LOGI("diff glitch detected, absDiff = %g", absDiff);
+                } else {
+                    mSumSquareSignal += predicted * predicted;
+                    mSumSquareNoise += diff * diff;
+                    // Track incoming signal and slowly adjust magnitude to account
+                    // for drift in the DRC or AGC.
+                    mSinAccumulator += sample * sinf(mInputPhase);
+                    mCosAccumulator += sample * cosf(mInputPhase);
+                    mFramesAccumulated++;
+                    // Must be a multiple of the period or the calculation will not be accurate.
+                    if (mFramesAccumulated == mSinePeriod) {
+                        const double coefficient = 0.1;
+                        double phaseOffset = 0.0;
+                        double magnitude = calculateMagnitude(&phaseOffset);
+                        // One pole averaging filter.
+                        setMagnitude((mMagnitude * (1.0 - coefficient)) + (magnitude * coefficient));
+
+                        mMeanSquareNoise = mSumSquareNoise * mInverseSinePeriod;
+                        mMeanSquareSignal = mSumSquareSignal * mInverseSinePeriod;
+                        resetAccumulator();
+
+                        if (abs(phaseOffset) > kMaxPhaseError) {
+                            result = ERROR_GLITCHES;
+                            onGlitchStart();
+                            LOGD("phase glitch detected, phaseOffset = %g", phaseOffset);
+                        } else if (mMagnitude < mThreshold) {
+                            result = ERROR_GLITCHES;
+                            onGlitchStart();
+                            LOGD("magnitude glitch detected, mMagnitude = %g", mMagnitude);
+                        }
+                    }
+                }
+                incrementInputPhase();
+            } break;
+
+            case STATE_GLITCHING: {
+                // Predict next sine value
+                mGlitchLength++;
+                float predicted = sinf(mInputPhase) * mMagnitude;
+                float diff = predicted - sample;
+                float absDiff = fabs(diff);
+                mMaxGlitchDelta = std::max(mMaxGlitchDelta, absDiff);
+                if (absDiff < mScaledTolerance) { // close enough?
+                    // If we get a full sine period of non-glitch samples in a row then consider the glitch over.
+                    // We don't want to just consider a zero crossing the end of a glitch.
+                    if (mNonGlitchCount++ > mSinePeriod) {
+                        onGlitchEnd();
+                    }
+                } else {
+                    mNonGlitchCount = 0;
+                    if (mGlitchLength > (4 * mSinePeriod)) {
+                        relock();
+                    }
+                }
+                incrementInputPhase();
+            } break;
+
+            case NUM_STATES: // not a real state
+                break;
+        }
+
+        mFrameCounter++;
+
+        return result;
+    }
+
+    // advance and wrap phase
+    void incrementInputPhase() {
+        mInputPhase += mPhaseIncrement;
+        if (mInputPhase > M_PI) {
+            mInputPhase -= (2.0 * M_PI);
+        }
+    }
+
+    // advance and wrap phase
+    void incrementOutputPhase() {
+        mOutputPhase += mPhaseIncrement;
+        if (mOutputPhase > M_PI) {
+            mOutputPhase -= (2.0 * M_PI);
+        }
+    }
+
+    /**
+     * @param frameData upon return, contains the reference sine wave
+     * @param channelCount
+     */
+    result_code processOutputFrame(float *frameData, int channelCount) override {
+        float output = 0.0f;
+        // Output sine wave so we can measure it.
+        if (mState != STATE_IDLE) {
+            float sinOut = sinf(mOutputPhase);
+            incrementOutputPhase();
+            output = (sinOut * mOutputAmplitude)
+                     + (mWhiteNoise.nextRandomDouble() * kNoiseAmplitude);
+            // LOGD("%5d: sin(%f) = %f, %f", i, mPhase, sinOut,  mPhaseIncrement);
+        }
+        frameData[0] = output;
+        for (int i = 1; i < channelCount; i++) {
+            frameData[i] = 0.0f;
+        }
+        return RESULT_OK;
+    }
+
+    void onGlitchStart() {
+        mGlitchCount++;
+//        LOGD("%5d: STARTED a glitch # %d", mFrameCounter, mGlitchCount);
+        mState = STATE_GLITCHING;
+        mGlitchLength = 1;
+        mNonGlitchCount = 0;
+    }
+
+    void onGlitchEnd() {
+//        LOGD("%5d: ENDED a glitch # %d, length = %d", mFrameCounter, mGlitchCount, mGlitchLength);
+        mState = STATE_LOCKED;
+        resetAccumulator();
+    }
+
+    // reset the sine wave detector
+    void resetAccumulator() {
+        mFramesAccumulated = 0;
+        mSinAccumulator = 0.0;
+        mCosAccumulator = 0.0;
+        mSumSquareSignal = 0.0;
+        mSumSquareNoise = 0.0;
+    }
+
+    void relock() {
+//        LOGD("relock: %d because of a very long %d glitch", mFrameCounter, mGlitchLength);
+        mState = STATE_WAITING_FOR_LOCK;
+        resetAccumulator();
+    }
+
+    void reset() override {
+        LoopbackProcessor::reset();
+        mState = STATE_IDLE;
+        mDownCounter = IDLE_FRAME_COUNT;
+        resetAccumulator();
+    }
+
+    void onStartTest() override {
+        LoopbackProcessor::onStartTest();
+        mSinePeriod = getSampleRate() / kTargetGlitchFrequency;
+        mOutputPhase = 0.0f;
+        mInverseSinePeriod = 1.0 / mSinePeriod;
+        mPhaseIncrement = 2.0 * M_PI * mInverseSinePeriod;
+        mGlitchCount = 0;
+        mMaxGlitchDelta = 0.0;
+        for (int i = 0; i < NUM_STATES; i++) {
+            mStateFrameCounters[i] = 0;
+        }
+    }
+
+private:
+
+    // These must match the values in GlitchActivity.java
+    enum sine_state_t {
+        STATE_IDLE,               // beginning
+        STATE_IMMUNE,             // ignoring input, waiting fo HW to settle
+        STATE_WAITING_FOR_SIGNAL, // looking for a loud signal
+        STATE_WAITING_FOR_LOCK,   // trying to lock onto the phase of the sine
+        STATE_LOCKED,             // locked on the sine wave, looking for glitches
+        STATE_GLITCHING,           // locked on the sine wave but glitching
+        NUM_STATES
+    };
+
+    enum constants {
+        // Arbitrary durations, assuming 48000 Hz
+                IDLE_FRAME_COUNT = 48 * 100,
+        IMMUNE_FRAME_COUNT = 48 * 100,
+        PERIODS_NEEDED_FOR_LOCK = 8,
+        MIN_SNRATIO_DB = 65
+    };
+
+    static constexpr float kNoiseAmplitude = 0.00; // Used to experiment with warbling caused by DRC.
+    static constexpr int kTargetGlitchFrequency = 607;
+    static constexpr double kMaxPhaseError = M_PI * 0.05;
+
+    float   mTolerance = 0.10; // scaled from 0.0 to 1.0
+    double  mThreshold = 0.005;
+    int     mSinePeriod = 1; // this will be set before use
+    double  mInverseSinePeriod = 1.0;
+
+    int32_t mStateFrameCounters[NUM_STATES];
+
+    double  mPhaseIncrement = 0.0;
+    double  mInputPhase = 0.0;
+    double  mOutputPhase = 0.0;
+    double  mMagnitude = 0.0;
+    int32_t mFramesAccumulated = 0;
+    double  mSinAccumulator = 0.0;
+    double  mCosAccumulator = 0.0;
+    float   mMaxGlitchDelta = 0.0f;
+    int32_t mGlitchCount = 0;
+    int32_t mNonGlitchCount = 0;
+    int32_t mGlitchLength = 0;
+    float   mScaledTolerance = 0.0;
+    int     mDownCounter = IDLE_FRAME_COUNT;
+    int32_t mFrameCounter = 0;
+    float   mOutputAmplitude = 0.75;
+
+    int32_t mForceGlitchDuration = 0; // if > 0 then force a glitch for debugging
+    int32_t mForceGlitchCounter = 4 * 48000; // count down and trigger at zero
+
+    // measure background noise continuously as a deviation from the expected signal
+    double  mSumSquareSignal = 0.0;
+    double  mSumSquareNoise = 0.0;
+    double  mMeanSquareSignal = 0.0;
+    double  mMeanSquareNoise = 0.0;
+
+    PeakDetector  mPeakFollower;
+
+    PseudoRandom  mWhiteNoise;
+
+    sine_state_t  mState = STATE_IDLE;
+};
+
+
+#endif //OBOETESTER_GLITCHANALYZER_H
diff --git a/apps/OboeTester/app/src/main/cpp/analyzer/LatencyAnalyzer.h b/apps/OboeTester/app/src/main/cpp/analyzer/LatencyAnalyzer.h
new file mode 100644
index 0000000..d0d1aa8
--- /dev/null
+++ b/apps/OboeTester/app/src/main/cpp/analyzer/LatencyAnalyzer.h
@@ -0,0 +1,611 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+/**
+ * Tools for measuring latency and for detecting glitches.
+ * These classes are pure math and can be used with any audio system.
+ */
+
+#ifndef ANALYZER_LATENCY_ANALYZER_H
+#define ANALYZER_LATENCY_ANALYZER_H
+
+#include <algorithm>
+#include <assert.h>
+#include <cctype>
+#include <math.h>
+#include <memory>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <vector>
+
+#include "RandomPulseGenerator.h"
+#include "PeakDetector.h"
+#include "PseudoRandom.h"
+
+#define LOOPBACK_RESULT_TAG  "RESULT: "
+
+static constexpr int32_t kDefaultSampleRate = 48000;
+static constexpr int32_t kMillisPerSecond   = 1000;
+static constexpr int32_t kMaxLatencyMillis  = 700;  // arbitrary and generous
+static constexpr double  kMinimumConfidence = 0.2;
+
+typedef struct LatencyReport_s {
+    int32_t latencyInFrames = 0.0;
+    double confidence = 0.0;
+
+    void reset() {
+        latencyInFrames = 0;
+        confidence = 0.0;
+    }
+} LatencyReport;
+
+// Calculate a normalized cross correlation.
+static double calculateNormalizedCorrelation(const float *a,
+                                             const float *b,
+                                             int windowSize)
+{
+    double correlation = 0.0;
+    double sumProducts = 0.0;
+    double sumSquares = 0.0;
+
+    // Correlate a against b.
+    for (int i = 0; i < windowSize; i++) {
+        float s1 = a[i];
+        float s2 = b[i];
+        // Use a normalized cross-correlation.
+        sumProducts += s1 * s2;
+        sumSquares += ((s1 * s1) + (s2 * s2));
+    }
+
+    if (sumSquares >= 1.0e-9) {
+        correlation = (float) (2.0 * sumProducts / sumSquares);
+    }
+    return correlation;
+}
+
+static double calculateRootMeanSquare(float *data, int32_t numSamples) {
+    double sum = 0.0;
+    for (int32_t i = 0; i < numSamples; i++) {
+        float sample = data[i];
+        sum += sample * sample;
+    }
+    return sqrt(sum / numSamples);
+}
+
+/**
+ * Monophonic recording with processing.
+ */
+class AudioRecording
+{
+public:
+    AudioRecording() {
+    }
+    ~AudioRecording() {
+        delete[] mData;
+    }
+
+    void allocate(int maxFrames) {
+        delete[] mData;
+        mData = new float[maxFrames];
+        mMaxFrames = maxFrames;
+    }
+
+    // Write SHORT data from the first channel.
+    int32_t write(int16_t *inputData, int32_t inputChannelCount, int32_t numFrames) {
+        // stop at end of buffer
+        if ((mFrameCounter + numFrames) > mMaxFrames) {
+            numFrames = mMaxFrames - mFrameCounter;
+        }
+        for (int i = 0; i < numFrames; i++) {
+            mData[mFrameCounter++] = inputData[i * inputChannelCount] * (1.0f / 32768);
+        }
+        return numFrames;
+    }
+
+    // Write FLOAT data from the first channel.
+    int32_t write(float *inputData, int32_t inputChannelCount, int32_t numFrames) {
+        // stop at end of buffer
+        if ((mFrameCounter + numFrames) > mMaxFrames) {
+            numFrames = mMaxFrames - mFrameCounter;
+        }
+        for (int i = 0; i < numFrames; i++) {
+            mData[mFrameCounter++] = inputData[i * inputChannelCount];
+        }
+        return numFrames;
+    }
+
+    // Write FLOAT data from the first channel.
+    int32_t write(float sample) {
+        // stop at end of buffer
+        if (mFrameCounter < mMaxFrames) {
+            mData[mFrameCounter++] = sample;
+        }
+        return 1;
+    }
+
+    void clear() {
+        mFrameCounter = 0;
+    }
+    int32_t size() {
+        return mFrameCounter;
+    }
+
+    bool isFull() {
+        return mFrameCounter >= mMaxFrames;
+    }
+
+    float *getData() {
+        return mData;
+    }
+
+    void setSampleRate(int32_t sampleRate) {
+        mSampleRate = sampleRate;
+    }
+
+    int32_t getSampleRate() {
+        return mSampleRate;
+    }
+
+    /**
+     * Square the samples so they are all positive and so the peaks are emphasized.
+     */
+    void square() {
+        for (int i = 0; i < mFrameCounter; i++) {
+            const float sample = mData[i];
+            mData[i] = sample * sample;
+        }
+    }
+
+    /**
+     * Amplify a signal so that the peak matches the specified target.
+     *
+     * @param target final max value
+     * @return gain applied to signal
+     */
+    float normalize(float target) {
+        float maxValue = 1.0e-9f;
+        for (int i = 0; i < mFrameCounter; i++) {
+            maxValue = std::max(maxValue, abs(mData[i]));
+        }
+        float gain = target / maxValue;
+        for (int i = 0; i < mFrameCounter; i++) {
+            mData[i] *= gain;
+        }
+        return gain;
+    }
+
+private:
+    float        *mData = nullptr;
+    int32_t       mFrameCounter = 0;
+    int32_t       mMaxFrames = 0;
+    int32_t       mSampleRate = kDefaultSampleRate; // common default
+};
+
+static int measureLatencyFromPulse(AudioRecording &recorded,
+                                   AudioRecording &pulse,
+                                   int32_t framesPerEncodedBit,
+                                   LatencyReport *report) {
+
+    report->latencyInFrames = 0;
+    report->confidence = 0.0;
+
+    int numCorrelations = recorded.size() - pulse.size();
+    if (numCorrelations < 10) {
+        LOGE("%s() recording too small = %d frames", __func__, recorded.size());
+        return -1;
+    }
+    std::unique_ptr<float[]> correlations= std::make_unique<float[]>(numCorrelations);
+
+    // Correlate pulse against the recorded data.
+    for (int i = 0; i < numCorrelations; i++) {
+        float correlation = (float) calculateNormalizedCorrelation(&recorded.getData()[i],
+                                                                   &pulse.getData()[0],
+                                                                   pulse.size());
+        correlations[i] = correlation;
+    }
+
+    // Find highest peak in correlation array.
+    float peakCorrelation = 0.0;
+    int peakIndex = -1;
+    for (int i = 0; i < numCorrelations; i++) {
+        float value = abs(correlations[i]);
+        if (value > peakCorrelation) {
+            peakCorrelation = value;
+            peakIndex = i;
+        }
+    }
+    if (peakIndex < 0) {
+        LOGE("%s() no signal for correlation", __func__);
+        return -2;
+    }
+
+    report->latencyInFrames = peakIndex;
+    report->confidence = peakCorrelation;
+
+    return 0;
+}
+
+// ====================================================================================
+class LoopbackProcessor {
+public:
+    virtual ~LoopbackProcessor() = default;
+
+    // Note that these values must match the switch in RoundTripLatencyActivity.h
+    enum result_code {
+        RESULT_OK = 0,
+        ERROR_NOISY = -99,
+        ERROR_VOLUME_TOO_LOW,
+        ERROR_VOLUME_TOO_HIGH,
+        ERROR_CONFIDENCE,
+        ERROR_INVALID_STATE,
+        ERROR_GLITCHES,
+        ERROR_NO_LOCK
+    };
+
+    virtual void onStartTest() {
+        reset();
+    }
+
+    virtual void reset() {
+        mResult = 0;
+        mResetCount++;
+    }
+
+    virtual result_code processInputFrame(float *frameData, int channelCount) = 0;
+    virtual result_code processOutputFrame(float *frameData, int channelCount) = 0;
+
+    void process(float *inputData, int inputChannelCount, int numInputFrames,
+                        float *outputData, int outputChannelCount, int numOutputFrames) {
+        int numBoth = std::min(numInputFrames, numOutputFrames);
+        // Process one frame at a time.
+        for (int i = 0; i < numBoth; i++) {
+            processInputFrame(inputData, inputChannelCount);
+            inputData += inputChannelCount;
+            processOutputFrame(outputData, outputChannelCount);
+            outputData += outputChannelCount;
+        }
+        // If there is more input than output.
+        for (int i = numBoth; i < numInputFrames; i++) {
+            processInputFrame(inputData, inputChannelCount);
+            inputData += inputChannelCount;
+        }
+        // If there is more output than input.
+        for (int i = numBoth; i < numOutputFrames; i++) {
+            processOutputFrame(outputData, outputChannelCount);
+            outputData += outputChannelCount;
+        }
+    }
+
+    virtual void analyze() = 0;
+
+    virtual void printStatus() {};
+
+    int32_t getResult() {
+        return mResult;
+    }
+
+    void setResult(int32_t result) {
+        mResult = result;
+    }
+
+    virtual bool isDone() {
+        return false;
+    }
+
+    virtual int save(const char *fileName) {
+        (void) fileName;
+        return -1;
+    }
+
+    virtual int load(const char *fileName) {
+        (void) fileName;
+        return -1;
+    }
+
+    virtual void setSampleRate(int32_t sampleRate) {
+        mSampleRate = sampleRate;
+    }
+
+    int32_t getSampleRate() {
+        return mSampleRate;
+    }
+
+    int32_t getResetCount() {
+        return mResetCount;
+    }
+
+    /** Called when not enough input frames could be read after synchronization.
+     */
+    virtual void onInsufficientRead() {
+        reset();
+    }
+
+protected:
+    int32_t   mResetCount = 0;
+
+private:
+    int32_t mSampleRate = kDefaultSampleRate;
+    int32_t mResult = 0;
+};
+
+class LatencyAnalyzer : public LoopbackProcessor {
+public:
+
+    LatencyAnalyzer() : LoopbackProcessor() {}
+    virtual ~LatencyAnalyzer() = default;
+
+    virtual int32_t getProgress() = 0;
+
+    virtual int getState() = 0;
+
+    // @return latency in frames
+    virtual int32_t getMeasuredLatency() = 0;
+
+    virtual double getMeasuredConfidence() = 0;
+
+    virtual double getBackgroundRMS() = 0;
+
+    virtual double getSignalRMS() = 0;
+
+};
+
+// ====================================================================================
+/**
+ * Measure latency given a loopback stream data.
+ * Use an encoded bit train as the sound source because it
+ * has an unambiguous correlation value.
+ * Uses a state machine to cycle through various stages.
+ *
+ */
+class PulseLatencyAnalyzer : public LatencyAnalyzer {
+public:
+
+    PulseLatencyAnalyzer() : LatencyAnalyzer() {
+        int32_t maxLatencyFrames = getSampleRate() * kMaxLatencyMillis / kMillisPerSecond;
+        int32_t numPulseBits = getSampleRate() * kPulseLengthMillis
+                / (kFramesPerEncodedBit * kMillisPerSecond);
+        int32_t  pulseLength = numPulseBits * kFramesPerEncodedBit;
+        mFramesToRecord = pulseLength + maxLatencyFrames;
+        LOGD("PulseLatencyAnalyzer: allocate recording with %d frames", mFramesToRecord);
+        mAudioRecording.allocate(mFramesToRecord);
+        mAudioRecording.setSampleRate(getSampleRate());
+        generateRandomPulse(pulseLength);
+    }
+
+    void generateRandomPulse(int32_t pulseLength) {
+        mPulse.allocate(pulseLength);
+        RandomPulseGenerator pulser(kFramesPerEncodedBit);
+        for (int i = 0; i < pulseLength; i++) {
+            mPulse.write(pulser.nextFloat());
+        }
+    }
+
+    int getState() override {
+        return mState;
+    }
+
+    void setSampleRate(int32_t sampleRate) override {
+        LoopbackProcessor::setSampleRate(sampleRate);
+        mAudioRecording.setSampleRate(sampleRate);
+    }
+
+    void reset() override {
+        LoopbackProcessor::reset();
+        mDownCounter = getSampleRate() / 2;
+        mLoopCounter = 0;
+
+        mPulseCursor = 0;
+        mBackgroundSumSquare = 0.0f;
+        mBackgroundSumCount = 0;
+        mBackgroundRMS = 0.0f;
+        mSignalRMS = 0.0f;
+
+        LOGD("state reset to STATE_MEASURE_BACKGROUND");
+        mState = STATE_MEASURE_BACKGROUND;
+        mAudioRecording.clear();
+        mLatencyReport.reset();
+    }
+
+    bool hasEnoughData() {
+        return mAudioRecording.isFull();
+    }
+
+    bool isDone() override {
+        return mState == STATE_DONE;
+    }
+
+    int32_t getProgress() override {
+        return mAudioRecording.size();
+    }
+
+    void analyze() override {
+        LOGD("PulseLatencyAnalyzer ---------------");
+        LOGD(LOOPBACK_RESULT_TAG "test.state             = %8d", mState);
+        LOGD(LOOPBACK_RESULT_TAG "test.state.name        = %8s", convertStateToText(mState));
+        LOGD(LOOPBACK_RESULT_TAG "background.rms         = %8f", mBackgroundRMS);
+
+        int32_t newResult = RESULT_OK;
+        if (mState != STATE_GOT_DATA) {
+            LOGD("WARNING - Bad state. Check volume on device.");
+            // setResult(ERROR_INVALID_STATE);
+        } else {
+            LOGD("Please wait several seconds for cross-correlation to complete.");
+            float gain = mAudioRecording.normalize(1.0f);
+            measureLatencyFromPulse(mAudioRecording,
+                                    mPulse,
+                                    kFramesPerEncodedBit,
+                                    &mLatencyReport);
+
+            if (mLatencyReport.confidence < kMinimumConfidence) {
+                LOGD("   ERROR - confidence too low!");
+                newResult = ERROR_CONFIDENCE;
+            } else {
+                mSignalRMS = calculateRootMeanSquare(
+                        &mAudioRecording.getData()[mLatencyReport.latencyInFrames], mPulse.size())
+                                / gain;
+            }
+#if OBOE_ENABLE_LOGGING
+            double latencyMillis = kMillisPerSecond * (double) mLatencyReport.latencyInFrames
+                                   / getSampleRate();
+#endif
+            LOGD(LOOPBACK_RESULT_TAG "latency.frames         = %8d",
+                   mLatencyReport.latencyInFrames);
+            LOGD(LOOPBACK_RESULT_TAG "latency.msec           = %8.2f",
+                   latencyMillis);
+            LOGD(LOOPBACK_RESULT_TAG "latency.confidence     = %8.6f",
+                   mLatencyReport.confidence);
+        }
+        mState = STATE_DONE;
+        if (getResult() == RESULT_OK) {
+            setResult(newResult);
+        }
+    }
+
+    int32_t getMeasuredLatency() override {
+        return mLatencyReport.latencyInFrames;
+    }
+
+    double getMeasuredConfidence() override {
+        return mLatencyReport.confidence;
+    }
+
+    double getBackgroundRMS() override {
+        return mBackgroundRMS;
+    }
+
+    double getSignalRMS() override {
+        return mSignalRMS;
+    }
+
+    void printStatus() override {
+        LOGD("st = %d", mState);
+    }
+
+    result_code processInputFrame(float *frameData, int channelCount) override {
+        echo_state nextState = mState;
+        mLoopCounter++;
+
+        switch (mState) {
+            case STATE_MEASURE_BACKGROUND:
+                // Measure background RMS on channel 0
+                mBackgroundSumSquare += frameData[0] * frameData[0];
+                mBackgroundSumCount++;
+                mDownCounter--;
+                if (mDownCounter <= 0) {
+                    mBackgroundRMS = sqrtf(mBackgroundSumSquare / mBackgroundSumCount);
+                    nextState = STATE_IN_PULSE;
+                    mPulseCursor = 0;
+                    LOGD("LatencyAnalyzer state => STATE_SENDING_PULSE");
+                }
+                break;
+
+            case STATE_IN_PULSE:
+                // Record input until the mAudioRecording is full.
+                mAudioRecording.write(frameData, channelCount, 1);
+                if (hasEnoughData()) {
+                    LOGD("LatencyAnalyzer state => STATE_GOT_DATA");
+                    nextState = STATE_GOT_DATA;
+                }
+                break;
+
+            case STATE_GOT_DATA:
+            case STATE_DONE:
+            default:
+                break;
+        }
+
+        mState = nextState;
+        return RESULT_OK;
+    }
+
+    result_code processOutputFrame(float *frameData, int channelCount) override {
+        switch (mState) {
+            case STATE_IN_PULSE:
+                if (mPulseCursor < mPulse.size()) {
+                    float pulseSample = mPulse.getData()[mPulseCursor++];
+                    for (int i = 0; i < channelCount; i++) {
+                        frameData[i] = pulseSample;
+                    }
+                } else {
+                    for (int i = 0; i < channelCount; i++) {
+                        frameData[i] = 0;
+                    }
+                }
+                break;
+
+            case STATE_MEASURE_BACKGROUND:
+            case STATE_GOT_DATA:
+            case STATE_DONE:
+            default:
+                for (int i = 0; i < channelCount; i++) {
+                    frameData[i] = 0.0f; // silence
+                }
+                break;
+        }
+
+        return RESULT_OK;
+    }
+
+private:
+
+    enum echo_state {
+        STATE_MEASURE_BACKGROUND,
+        STATE_IN_PULSE,
+        STATE_GOT_DATA, // must match RoundTripLatencyActivity.java
+        STATE_DONE,
+    };
+
+    const char *convertStateToText(echo_state state) {
+        const char *result = "Unknown";
+        switch(state) {
+            case STATE_MEASURE_BACKGROUND:
+                result = "INIT";
+                break;
+            case STATE_IN_PULSE:
+                result = "PULSE";
+                break;
+            case STATE_GOT_DATA:
+                result = "GOT_DATA";
+                break;
+            case STATE_DONE:
+                result = "DONE";
+                break;
+        }
+        return result;
+    }
+
+    int32_t         mDownCounter = 500;
+    int32_t         mLoopCounter = 0;
+    echo_state      mState = STATE_MEASURE_BACKGROUND;
+
+    static constexpr int32_t kFramesPerEncodedBit = 8; // multiple of 2
+    static constexpr int32_t kPulseLengthMillis = 500;
+
+    AudioRecording     mPulse;
+    int32_t            mPulseCursor = 0;
+
+    float              mBackgroundSumSquare = 0.0f;
+    int32_t            mBackgroundSumCount = 0;
+    float              mBackgroundRMS = 0.0f;
+    float              mSignalRMS = 0.0f;
+    int32_t            mFramesToRecord = 0;
+
+    AudioRecording     mAudioRecording; // contains only the input after starting the pulse
+    LatencyReport      mLatencyReport;
+};
+
+#endif // ANALYZER_LATENCY_ANALYZER_H
diff --git a/apps/OboeTester/app/src/main/cpp/util/ManchesterEncoder.h b/apps/OboeTester/app/src/main/cpp/analyzer/ManchesterEncoder.h
similarity index 95%
rename from apps/OboeTester/app/src/main/cpp/util/ManchesterEncoder.h
rename to apps/OboeTester/app/src/main/cpp/analyzer/ManchesterEncoder.h
index 1ffd1b1..b3d12b3 100644
--- a/apps/OboeTester/app/src/main/cpp/util/ManchesterEncoder.h
+++ b/apps/OboeTester/app/src/main/cpp/analyzer/ManchesterEncoder.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef UTIL_MANCHESTER_ENCODER_H
-#define UTIL_MANCHESTER_ENCODER_H
+#ifndef ANALYZER_MANCHESTER_ENCODER_H
+#define ANALYZER_MANCHESTER_ENCODER_H
 
 #include <cstdint>
 
@@ -93,4 +93,4 @@
     uint8_t   mCurrentByte = 0;
     bool      mCurrentBit = false;
 };
-#endif //UTIL_MANCHESTER_ENCODER_H
+#endif //ANALYZER_MANCHESTER_ENCODER_H
diff --git a/apps/OboeTester/app/src/main/cpp/PeakDetector.h b/apps/OboeTester/app/src/main/cpp/analyzer/PeakDetector.h
similarity index 86%
rename from apps/OboeTester/app/src/main/cpp/PeakDetector.h
rename to apps/OboeTester/app/src/main/cpp/analyzer/PeakDetector.h
index 5e4b92c..9139e42 100644
--- a/apps/OboeTester/app/src/main/cpp/PeakDetector.h
+++ b/apps/OboeTester/app/src/main/cpp/analyzer/PeakDetector.h
@@ -14,13 +14,11 @@
  * limitations under the License.
  */
 
-#ifndef OBOE_TESTER_PEAK_DETECTOR_H
-#define OBOE_TESTER_PEAK_DETECTOR_H
+#ifndef ANALYZER_PEAK_DETECTOR_H
+#define ANALYZER_PEAK_DETECTOR_H
 
 #include <math.h>
 
-constexpr double kDefaultDecay = 0.9999; //
-
 class PeakDetector {
 public:
 
@@ -42,7 +40,9 @@
     }
 
 private:
+    static constexpr float kDefaultDecay = 0.99f;
+
     double mLevel = 0.0;
     double mDecay = kDefaultDecay;
 };
-#endif //OBOE_TESTER_PEAK_DETECTOR_H
+#endif //ANALYZER_PEAK_DETECTOR_H
diff --git a/apps/OboeTester/app/src/main/cpp/analyzer/PseudoRandom.h b/apps/OboeTester/app/src/main/cpp/analyzer/PseudoRandom.h
new file mode 100644
index 0000000..4aedbe0
--- /dev/null
+++ b/apps/OboeTester/app/src/main/cpp/analyzer/PseudoRandom.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+
+#ifndef ANALYZER_PSEUDORANDOM_H
+#define ANALYZER_PSEUDORANDOM_H
+
+#include <cctype>
+
+class PseudoRandom {
+public:
+    PseudoRandom() {}
+    PseudoRandom(int64_t seed)
+            :    mSeed(seed)
+    {}
+
+    /**
+     * Returns the next random double from -1.0 to 1.0
+     *
+     * @return value from -1.0 to 1.0
+     */
+    double nextRandomDouble() {
+        return nextRandomInteger() * (0.5 / (((int32_t)1) << 30));
+    }
+
+    /** Calculate random 32 bit number using linear-congruential method.
+     */
+    int32_t nextRandomInteger() {
+#if __has_builtin(__builtin_mul_overflow) && __has_builtin(__builtin_add_overflow)
+        int64_t prod;
+        // Use values for 64-bit sequence from MMIX by Donald Knuth.
+        __builtin_mul_overflow(mSeed, (int64_t)6364136223846793005, &prod);
+        __builtin_add_overflow(prod, (int64_t)1442695040888963407, &mSeed);
+#else
+        mSeed = (mSeed * (int64_t)6364136223846793005) + (int64_t)1442695040888963407;
+#endif
+        return (int32_t) (mSeed >> 32); // The higher bits have a longer sequence.
+    }
+
+private:
+    int64_t mSeed = 99887766;
+};
+
+#endif //ANALYZER_PSEUDORANDOM_H
diff --git a/apps/OboeTester/app/src/main/cpp/RandomPulseGenerator.h b/apps/OboeTester/app/src/main/cpp/analyzer/RandomPulseGenerator.h
similarity index 85%
rename from apps/OboeTester/app/src/main/cpp/RandomPulseGenerator.h
rename to apps/OboeTester/app/src/main/cpp/analyzer/RandomPulseGenerator.h
index d861289..f0623cc 100644
--- a/apps/OboeTester/app/src/main/cpp/RandomPulseGenerator.h
+++ b/apps/OboeTester/app/src/main/cpp/analyzer/RandomPulseGenerator.h
@@ -14,11 +14,11 @@
  * limitations under the License.
  */
 
-#ifndef OBOETESTER_RANDOM_PULSE_GENERATOR_H
-#define OBOETESTER_RANDOM_PULSE_GENERATOR_H
+#ifndef ANALYZER_RANDOM_PULSE_GENERATOR_H
+#define ANALYZER_RANDOM_PULSE_GENERATOR_H
 
 #include <stdlib.h>
-#include "util/RoundedManchesterEncoder.h"
+#include "RoundedManchesterEncoder.h"
 
 /**
  * Encode random ones and zeros using Manchester Code per IEEE 802.3.
@@ -38,4 +38,4 @@
     }
 };
 
-#endif //OBOETESTER_RANDOM_PULSE_GENERATOR_H
+#endif //ANALYZER_RANDOM_PULSE_GENERATOR_H
diff --git a/apps/OboeTester/app/src/main/cpp/util/RoundedManchesterEncoder.h b/apps/OboeTester/app/src/main/cpp/analyzer/RoundedManchesterEncoder.h
similarity index 94%
rename from apps/OboeTester/app/src/main/cpp/util/RoundedManchesterEncoder.h
rename to apps/OboeTester/app/src/main/cpp/analyzer/RoundedManchesterEncoder.h
index 92967c5..b1ba949 100644
--- a/apps/OboeTester/app/src/main/cpp/util/RoundedManchesterEncoder.h
+++ b/apps/OboeTester/app/src/main/cpp/analyzer/RoundedManchesterEncoder.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef UTIL_ROUNDED_MANCHESTER_ENCODER_H
-#define UTIL_ROUNDED_MANCHESTER_ENCODER_H
+#ifndef ANALYZER_ROUNDED_MANCHESTER_ENCODER_H
+#define ANALYZER_ROUNDED_MANCHESTER_ENCODER_H
 
 #include <math.h>
 #include <memory.h>
@@ -86,4 +86,4 @@
     std::unique_ptr<float[]> mZeroAfterOne;
 };
 
-#endif //UTIL_ROUNDED_MANCHESTER_ENCODER_H
+#endif //ANALYZER_ROUNDED_MANCHESTER_ENCODER_H