Opensource ML embedded evaluation kit

Change-Id: I12e807f19f5cacad7cef82572b6dd48252fd61fd
diff --git a/source/application/main/Classifier.cc b/source/application/main/Classifier.cc
new file mode 100644
index 0000000..bc2c378
--- /dev/null
+++ b/source/application/main/Classifier.cc
@@ -0,0 +1,191 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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.
+ */
+#include "Classifier.hpp"
+
+#include "hal.h"
+#include "TensorFlowLiteMicro.hpp"
+
+#include <vector>
+#include <string>
+#include <set>
+#include <cstdint>
+
+namespace arm {
+namespace app {
+
+    template<typename T>
+    bool Classifier::_GetTopNResults(TfLiteTensor* tensor,
+                         std::vector<ClassificationResult>& vecResults,
+                         uint32_t topNCount,
+                         const std::vector <std::string>& labels)
+    {
+        std::set<std::pair<T, uint32_t>> sortedSet;
+
+        /* NOTE: inputVec's size verification against labels should be
+         *       checked by the calling/public function. */
+        T* tensorData = tflite::GetTensorData<T>(tensor);
+
+        /* Set initial elements. */
+        for (uint32_t i = 0; i < topNCount; ++i) {
+            sortedSet.insert({tensorData[i], i});
+        }
+
+        /* Initialise iterator. */
+        auto setFwdIter = sortedSet.begin();
+
+        /* Scan through the rest of elements with compare operations. */
+        for (uint32_t i = topNCount; i < labels.size(); ++i) {
+            if (setFwdIter->first < tensorData[i]) {
+                sortedSet.erase(*setFwdIter);
+                sortedSet.insert({tensorData[i], i});
+                setFwdIter = sortedSet.begin();
+            }
+        }
+
+        /* Final results' container. */
+        vecResults = std::vector<ClassificationResult>(topNCount);
+
+        /* For getting the floating point values, we need quantization parameters. */
+        QuantParams quantParams = GetTensorQuantParams(tensor);
+
+        /* Reset the iterator to the largest element - use reverse iterator. */
+        auto setRevIter = sortedSet.rbegin();
+
+        /* Populate results
+         * Note: we could combine this loop with the loop above, but that
+         *       would, involve more multiplications and other operations.
+         **/
+        for (size_t i = 0; i < vecResults.size(); ++i, ++setRevIter) {
+            double score = static_cast<int> (setRevIter->first);
+            vecResults[i].m_normalisedVal = quantParams.scale *
+                                         (score - quantParams.offset);
+            vecResults[i].m_label = labels[setRevIter->second];
+            vecResults[i].m_labelIdx = setRevIter->second;
+        }
+
+        return true;
+    }
+
+    template<>
+    bool Classifier::_GetTopNResults<float>(TfLiteTensor* tensor,
+                                     std::vector<ClassificationResult>& vecResults,
+                                     uint32_t topNCount,
+                                     const std::vector <std::string>& labels)
+    {
+        std::set<std::pair<float, uint32_t>> sortedSet;
+
+        /* NOTE: inputVec's size verification against labels should be
+         *       checked by the calling/public function. */
+        float* tensorData = tflite::GetTensorData<float>(tensor);
+
+        /* Set initial elements. */
+        for (uint32_t i = 0; i < topNCount; ++i) {
+            sortedSet.insert({tensorData[i], i});
+        }
+
+        /* Initialise iterator. */
+        auto setFwdIter = sortedSet.begin();
+
+        /* Scan through the rest of elements with compare operations. */
+        for (uint32_t i = topNCount; i < labels.size(); ++i) {
+            if (setFwdIter->first < tensorData[i]) {
+                sortedSet.erase(*setFwdIter);
+                sortedSet.insert({tensorData[i], i});
+                setFwdIter = sortedSet.begin();
+            }
+        }
+
+        /* Final results' container. */
+        vecResults = std::vector<ClassificationResult>(topNCount);
+
+        /* Reset the iterator to the largest element - use reverse iterator. */
+        auto setRevIter = sortedSet.rbegin();
+
+        /* Populate results
+         * Note: we could combine this loop with the loop above, but that
+         *       would, involve more multiplications and other operations.
+         **/
+        for (size_t i = 0; i < vecResults.size(); ++i, ++setRevIter) {
+            vecResults[i].m_normalisedVal = setRevIter->first;
+            vecResults[i].m_label = labels[setRevIter->second];
+            vecResults[i].m_labelIdx = setRevIter->second;
+        }
+
+        return true;
+    }
+
+    template bool  Classifier::_GetTopNResults<uint8_t>(TfLiteTensor* tensor,
+                                           std::vector<ClassificationResult>& vecResults,
+                                           uint32_t topNCount, const std::vector <std::string>& labels);
+
+    template bool  Classifier::_GetTopNResults<int8_t>(TfLiteTensor* tensor,
+                                          std::vector<ClassificationResult>& vecResults,
+                                          uint32_t topNCount, const std::vector <std::string>& labels);
+
+    bool  Classifier::GetClassificationResults(
+        TfLiteTensor* outputTensor,
+        std::vector<ClassificationResult>& vecResults,
+        const std::vector <std::string>& labels, uint32_t topNCount)
+    {
+        if (outputTensor == nullptr) {
+            printf_err("Output vector is null pointer.\n");
+            return false;
+        }
+
+        uint32_t totalOutputSize = 1;
+        for (int inputDim = 0; inputDim < outputTensor->dims->size; inputDim++){
+            totalOutputSize *= outputTensor->dims->data[inputDim];
+        }
+
+        /* Sanity checks. */
+        if (totalOutputSize < topNCount) {
+            printf_err("Output vector is smaller than %u\n", topNCount);
+            return false;
+        } else if (totalOutputSize != labels.size()) {
+            printf_err("Output size doesn't match the labels' size\n");
+            return false;
+        }
+
+        bool resultState;
+        vecResults.clear();
+
+        /* Get the top N results. */
+        switch (outputTensor->type) {
+            case kTfLiteUInt8:
+                resultState = _GetTopNResults<uint8_t>(outputTensor, vecResults, topNCount, labels);
+                break;
+            case kTfLiteInt8:
+                resultState = _GetTopNResults<int8_t>(outputTensor, vecResults, topNCount, labels);
+                break;
+            case kTfLiteFloat32:
+                resultState = _GetTopNResults<float>(outputTensor, vecResults, topNCount, labels);
+                break;
+            default:
+                printf_err("Tensor type %s not supported by classifier\n", TfLiteTypeGetName(outputTensor->type));
+                return false;
+        }
+
+        if (!resultState) {
+            printf_err("Failed to get sorted set\n");
+            return false;
+        }
+
+        return true;
+    }
+
+} /* namespace app */
+} /* namespace arm */
\ No newline at end of file
diff --git a/source/application/main/Main.cc b/source/application/main/Main.cc
new file mode 100644
index 0000000..6e1c620
--- /dev/null
+++ b/source/application/main/Main.cc
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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.
+ */
+
+/****************************************************************************\
+ *               Main application file for ARM NPU on MPS3 board             *
+\****************************************************************************/
+
+#include "hal.h"                    /* our hardware abstraction api */
+#include "TensorFlowLiteMicro.hpp"  /* our inference logic api */
+
+#include <cstdio>
+
+extern void main_loop(hal_platform& platform);
+
+#if defined(__ARMCC_VERSION) && (__ARMCC_VERSION >= 6010050)
+__ASM(" .global __ARM_use_no_argv\n");
+#endif
+
+/* Print application information. */
+static void print_application_intro()
+{
+    info("%s\n", PRJ_DES_STR);
+    info("Target system design: %s\n", DESIGN_NAME);
+    info("Version %s Build date: " __DATE__ " @ " __TIME__ "\n", PRJ_VER_STR);
+    info("Copyright (C) ARM Ltd 2020. All rights reserved.\n\n");
+}
+
+int main ()
+{
+    hal_platform    platform;
+    data_acq_module dataAcq;
+    data_psn_module dataPsn;
+    platform_timer  timer;
+
+    /* Initialise the HAL and platform. */
+    hal_init(&platform, &dataAcq, &dataPsn, &timer);
+
+    if (0 == hal_platform_init(&platform)) {
+        /* Application information, UART should have been initialised. */
+        print_application_intro();
+
+        /* Check the version of TensorFlow Lite Micro. */
+        PrintTensorFlowVersion();
+
+        /* Run the application. */
+        main_loop(platform);
+    }
+
+    /* This is unreachable without errors. */
+    info("program terminating...\n");
+
+    /* Release platform. */
+    hal_platform_release(&platform);
+    return 0;
+}
+
diff --git a/source/application/main/Mfcc.cc b/source/application/main/Mfcc.cc
new file mode 100644
index 0000000..bf16159
--- /dev/null
+++ b/source/application/main/Mfcc.cc
@@ -0,0 +1,354 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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.
+ */
+#include "Mfcc.hpp"
+
+#include "PlatformMath.hpp"
+
+#include <cfloat>
+
+namespace arm {
+namespace app {
+namespace audio {
+
+    MfccParams::MfccParams(
+                    const float samplingFreq,
+                    const uint32_t numFbankBins,
+                    const float melLoFreq,
+                    const float melHiFreq,
+                    const uint32_t numMfccFeats,
+                    const uint32_t frameLen,
+                    const bool useHtkMethod):
+                        m_samplingFreq(samplingFreq),
+                        m_numFbankBins(numFbankBins),
+                        m_melLoFreq(melLoFreq),
+                        m_melHiFreq(melHiFreq),
+                        m_numMfccFeatures(numMfccFeats),
+                        m_frameLen(frameLen),
+
+                        /* Smallest power of 2 >= frame length. */
+                        m_frameLenPadded(pow(2, ceil((log(frameLen)/log(2))))),
+                        m_useHtkMethod(useHtkMethod)
+    {}
+
+    std::string MfccParams::Str()
+    {
+        char strC[1024];
+        snprintf(strC, sizeof(strC) - 1, "\n   \
+            \n\t Sampling frequency:         %f\
+            \n\t Number of filter banks:     %u\
+            \n\t Mel frequency limit (low):  %f\
+            \n\t Mel frequency limit (high): %f\
+            \n\t Number of MFCC features:    %u\
+            \n\t Frame length:               %u\
+            \n\t Padded frame length:        %u\
+            \n\t Using HTK for Mel scale:    %s\n",
+                this->m_samplingFreq, this->m_numFbankBins, this->m_melLoFreq,
+                this->m_melHiFreq, this->m_numMfccFeatures, this->m_frameLen,
+                this->m_frameLenPadded, this->m_useHtkMethod ? "yes" : "no");
+        return std::string{strC};
+    }
+
+    MFCC::MFCC(const MfccParams& params):
+        _m_params(params),
+        _m_filterBankInitialised(false)
+    {
+        this->_m_buffer = std::vector<float>(
+                            this->_m_params.m_frameLenPadded, 0.0);
+        this->_m_frame = std::vector<float>(
+                            this->_m_params.m_frameLenPadded, 0.0);
+        this->_m_melEnergies = std::vector<float>(
+                                this->_m_params.m_numFbankBins, 0.0);
+
+        this->_m_windowFunc = std::vector<float>(this->_m_params.m_frameLen);
+        const float multiplier = 2 * M_PI / this->_m_params.m_frameLen;
+
+        /* Create window function. */
+        for (size_t i = 0; i < this->_m_params.m_frameLen; i++) {
+            this->_m_windowFunc[i] = (0.5 - (0.5 *
+                math::MathUtils::CosineF32(static_cast<float>(i) * multiplier)));
+        }
+
+        math::MathUtils::FftInitF32(this->_m_params.m_frameLenPadded, this->_m_fftInstance);
+        debug("Instantiated MFCC object: %s\n", this->_m_params.Str().c_str());
+    }
+
+    void MFCC::Init()
+    {
+        this->_InitMelFilterBank();
+    }
+
+    float MFCC::MelScale(const float freq, const bool useHTKMethod)
+    {
+        if (useHTKMethod) {
+            return 1127.0f * logf (1.0f + freq / 700.0f);
+        } else {
+            /* Slaney formula for mel scale. */
+
+            float mel = freq / ms_freqStep;
+
+            if (freq >= ms_minLogHz) {
+                mel = ms_minLogMel + logf(freq / ms_minLogHz) / ms_logStep;
+            }
+            return mel;
+        }
+    }
+
+    float MFCC::InverseMelScale(const float melFreq, const bool useHTKMethod)
+    {
+        if (useHTKMethod) {
+            return 700.0f * (expf (melFreq / 1127.0f) - 1.0f);
+        } else {
+            /* Slaney formula for mel scale. */
+            float freq = ms_freqStep * melFreq;
+
+            if (melFreq >= ms_minLogMel) {
+                freq = ms_minLogHz * expf(ms_logStep * (melFreq - ms_minLogMel));
+            }
+            return freq;
+        }
+    }
+
+
+    bool MFCC::ApplyMelFilterBank(
+            std::vector<float>&                 fftVec,
+            std::vector<std::vector<float>>&    melFilterBank,
+            std::vector<int32_t>&               filterBankFilterFirst,
+            std::vector<int32_t>&               filterBankFilterLast,
+            std::vector<float>&                 melEnergies)
+    {
+        const size_t numBanks = melEnergies.size();
+
+        if (numBanks != filterBankFilterFirst.size() ||
+                numBanks != filterBankFilterLast.size()) {
+            printf_err("unexpected filter bank lengths\n");
+            return false;
+        }
+
+        for (size_t bin = 0; bin < numBanks; ++bin) {
+            auto filterBankIter = melFilterBank[bin].begin();
+            float melEnergy = FLT_MIN;  /* Avoid log of zero at later stages */
+            int32_t firstIndex = filterBankFilterFirst[bin];
+            int32_t lastIndex = filterBankFilterLast[bin];
+
+            for (int i = firstIndex; i <= lastIndex; i++) {
+                float energyRep = math::MathUtils::SqrtF32(fftVec[i]);
+                melEnergy += (*filterBankIter++ * energyRep);
+            }
+
+            melEnergies[bin] = melEnergy;
+        }
+
+        return true;
+    }
+
+    void MFCC::ConvertToLogarithmicScale(std::vector<float>& melEnergies)
+    {
+        for (size_t bin = 0; bin < melEnergies.size(); ++bin) {
+            melEnergies[bin] = logf(melEnergies[bin]);
+        }
+    }
+
+    void MFCC::_ConvertToPowerSpectrum()
+    {
+        const uint32_t halfDim = this->_m_params.m_frameLenPadded / 2;
+
+        /* Handle this special case. */
+        float firstEnergy = this->_m_buffer[0] * this->_m_buffer[0];
+        float lastEnergy = this->_m_buffer[1] * this->_m_buffer[1];
+
+        math::MathUtils::ComplexMagnitudeSquaredF32(
+                            this->_m_buffer.data(),
+                            this->_m_buffer.size(),
+                            this->_m_buffer.data(),
+                            this->_m_buffer.size()/2);
+
+        this->_m_buffer[0] = firstEnergy;
+        this->_m_buffer[halfDim] = lastEnergy;
+    }
+
+    std::vector<float> MFCC::CreateDCTMatrix(
+                                const int32_t inputLength,
+                                const int32_t coefficientCount)
+    {
+        std::vector<float> dctMatix(inputLength * coefficientCount);
+
+        const float normalizer = math::MathUtils::SqrtF32(2.0f/inputLength);
+        const float angleIncr = M_PI/inputLength;
+        float angle = 0;
+
+        for (int32_t k = 0, m = 0; k < coefficientCount; k++, m += inputLength) {
+            for (int32_t n = 0; n < inputLength; n++) {
+                dctMatix[m+n] = normalizer *
+                    math::MathUtils::CosineF32((n + 0.5) * angle);
+            }
+            angle += angleIncr;
+        }
+
+        return dctMatix;
+    }
+
+    float MFCC::GetMelFilterBankNormaliser(
+                    const float&    leftMel,
+                    const float&    rightMel,
+                    const bool      useHTKMethod)
+    {
+        UNUSED(leftMel);
+        UNUSED(rightMel);
+        UNUSED(useHTKMethod);
+
+        /* By default, no normalisation => return 1 */
+        return 1.f;
+    }
+
+    void MFCC::_InitMelFilterBank()
+    {
+        if (!this->_IsMelFilterBankInited()) {
+            this->_m_melFilterBank = this->_CreateMelFilterBank();
+            this->_m_dctMatrix = this->CreateDCTMatrix(
+                                    this->_m_params.m_numFbankBins,
+                                    this->_m_params.m_numMfccFeatures);
+            this->_m_filterBankInitialised = true;
+        }
+    }
+
+    bool MFCC::_IsMelFilterBankInited()
+    {
+        return this->_m_filterBankInitialised;
+    }
+
+    void MFCC::_MfccComputePreFeature(const std::vector<int16_t>& audioData)
+    {
+        this->_InitMelFilterBank();
+
+        /* TensorFlow way of normalizing .wav data to (-1, 1). */
+        constexpr float normaliser = 1.0/(1<<15);
+        for (size_t i = 0; i < this->_m_params.m_frameLen; i++) {
+            this->_m_frame[i] = static_cast<float>(audioData[i]) * normaliser;
+        }
+
+        /* Apply window function to input frame. */
+        for(size_t i = 0; i < this->_m_params.m_frameLen; i++) {
+            this->_m_frame[i] *= this->_m_windowFunc[i];
+        }
+
+        /* Set remaining frame values to 0. */
+        std::fill(this->_m_frame.begin() + this->_m_params.m_frameLen,this->_m_frame.end(), 0);
+
+        /* Compute FFT. */
+        math::MathUtils::FftF32(this->_m_frame, this->_m_buffer, this->_m_fftInstance);
+
+        /* Convert to power spectrum. */
+        this->_ConvertToPowerSpectrum();
+
+        /* Apply mel filterbanks. */
+        if (!this->ApplyMelFilterBank(this->_m_buffer,
+                                      this->_m_melFilterBank,
+                                      this->_m_filterBankFilterFirst,
+                                      this->_m_filterBankFilterLast,
+                                      this->_m_melEnergies)) {
+            printf_err("Failed to apply MEL filter banks\n");
+        }
+
+        /* Convert to logarithmic scale. */
+        this->ConvertToLogarithmicScale(this->_m_melEnergies);
+    }
+
+    std::vector<float> MFCC::MfccCompute(const std::vector<int16_t>& audioData)
+    {
+        this->_MfccComputePreFeature(audioData);
+
+        std::vector<float> mfccOut(this->_m_params.m_numMfccFeatures);
+
+        float * ptrMel = this->_m_melEnergies.data();
+        float * ptrDct = this->_m_dctMatrix.data();
+        float * ptrMfcc = mfccOut.data();
+
+        /* Take DCT. Uses matrix mul. */
+        for (size_t i = 0, j = 0; i < mfccOut.size();
+                    ++i, j += this->_m_params.m_numFbankBins) {
+            *ptrMfcc++ = math::MathUtils::DotProductF32(
+                                            ptrDct + j,
+                                            ptrMel,
+                                            this->_m_params.m_numFbankBins);
+        }
+        return mfccOut;
+    }
+
+    std::vector<std::vector<float>> MFCC::_CreateMelFilterBank()
+    {
+        size_t numFftBins = this->_m_params.m_frameLenPadded / 2;
+        float fftBinWidth = static_cast<float>(this->_m_params.m_samplingFreq) / this->_m_params.m_frameLenPadded;
+
+        float melLowFreq = MFCC::MelScale(this->_m_params.m_melLoFreq,
+                                          this->_m_params.m_useHtkMethod);
+        float melHighFreq = MFCC::MelScale(this->_m_params.m_melHiFreq,
+                                           this->_m_params.m_useHtkMethod);
+        float melFreqDelta = (melHighFreq - melLowFreq) / (this->_m_params.m_numFbankBins + 1);
+
+        std::vector<float> thisBin = std::vector<float>(numFftBins);
+        std::vector<std::vector<float>> melFilterBank(
+                                            this->_m_params.m_numFbankBins);
+        this->_m_filterBankFilterFirst =
+                        std::vector<int32_t>(this->_m_params.m_numFbankBins);
+        this->_m_filterBankFilterLast =
+                        std::vector<int32_t>(this->_m_params.m_numFbankBins);
+
+        for (size_t bin = 0; bin < this->_m_params.m_numFbankBins; bin++) {
+            float leftMel = melLowFreq + bin * melFreqDelta;
+            float centerMel = melLowFreq + (bin + 1) * melFreqDelta;
+            float rightMel = melLowFreq + (bin + 2) * melFreqDelta;
+
+            int32_t firstIndex = -1;
+            int32_t lastIndex = -1;
+            const float normaliser = this->GetMelFilterBankNormaliser(leftMel, rightMel, this->_m_params.m_useHtkMethod);
+
+            for (size_t i = 0; i < numFftBins; i++) {
+                float freq = (fftBinWidth * i);  /* Center freq of this fft bin. */
+                float mel = MFCC::MelScale(freq, this->_m_params.m_useHtkMethod);
+                thisBin[i] = 0.0;
+
+                if (mel > leftMel && mel < rightMel) {
+                    float weight;
+                    if (mel <= centerMel) {
+                        weight = (mel - leftMel) / (centerMel - leftMel);
+                    } else {
+                        weight = (rightMel - mel) / (rightMel - centerMel);
+                    }
+
+                    thisBin[i] = weight * normaliser;
+                    if (firstIndex == -1) {
+                        firstIndex = i;
+                    }
+                    lastIndex = i;
+                }
+            }
+
+            this->_m_filterBankFilterFirst[bin] = firstIndex;
+            this->_m_filterBankFilterLast[bin] = lastIndex;
+
+            /* Copy the part we care about. */
+            for (int32_t i = firstIndex; i <= lastIndex; i++) {
+                melFilterBank[bin].push_back(thisBin[i]);
+            }
+        }
+
+        return melFilterBank;
+    }
+
+} /* namespace audio */
+} /* namespace app */
+} /* namespace arm */
diff --git a/source/application/main/PlatformMath.cc b/source/application/main/PlatformMath.cc
new file mode 100644
index 0000000..a9f5049
--- /dev/null
+++ b/source/application/main/PlatformMath.cc
@@ -0,0 +1,196 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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.
+ */
+#include "PlatformMath.hpp"
+
+#if 0 == ARM_DSP_AVAILABLE
+    #include <cmath>
+    #include <numeric>
+#endif /* 0 == ARM_DSP_AVAILABLE */
+
+namespace arm {
+namespace app {
+namespace math {
+
+    float MathUtils::CosineF32(float radians)
+    {
+#if ARM_DSP_AVAILABLE
+        return arm_cos_f32(radians);
+#else /* ARM_DSP_AVAILABLE */
+        return cos(radians);
+#endif /* ARM_DSP_AVAILABLE */
+    }
+
+    float MathUtils::SqrtF32(float input)
+    {
+#if ARM_DSP_AVAILABLE
+        float output = 0.f;
+        arm_sqrt_f32(input, &output);
+        return output;
+#else /* ARM_DSP_AVAILABLE */
+        return sqrtf(input);
+#endif /* ARM_DSP_AVAILABLE */
+    }
+
+    float MathUtils::MeanF32(float* ptrSrc, const uint32_t srcLen)
+    {
+        if (!srcLen) {
+            return 0.f;
+        }
+
+#if ARM_DSP_AVAILABLE
+        float result = 0.f;
+        arm_mean_f32(ptrSrc, srcLen, &result);
+        return result;
+#else /* ARM_DSP_AVAILABLE */
+        float acc = std::accumulate(ptrSrc, ptrSrc + srcLen, 0.0);
+        return acc/srcLen;
+#endif /* ARM_DSP_AVAILABLE */
+    }
+
+    float MathUtils::StdDevF32(float* ptrSrc, const uint32_t srcLen,
+                               const float mean)
+    {
+        if (!srcLen) {
+            return 0.f;
+        }
+#if ARM_DSP_AVAILABLE
+        /**
+         * Note Standard deviation calculation can be off
+         * by > 0.01 but less than < 0.1, according to
+         * preliminary findings.
+         **/
+        UNUSED(mean);
+        float stdDev = 0;
+        arm_std_f32(ptrSrc, srcLen, &stdDev);
+        return stdDev;
+#else /* ARM_DSP_AVAILABLE */
+        auto VarianceFunction = [=](float acc, const float value) {
+            return acc + (((value - mean) * (value - mean))/ srcLen);
+        };
+
+        float acc = std::accumulate(ptrSrc, ptrSrc + srcLen, 0.0,
+                                    VarianceFunction);
+
+        return sqrtf(acc);
+#endif /* ARM_DSP_AVAILABLE */
+    }
+
+    bool MathUtils::FftInitF32(const uint16_t fftLen, arm::app::math::FftInstance& fftInstance)
+    {
+#if ARM_DSP_AVAILABLE
+        if (!fftInstance.initialised) {
+            arm_status status = arm_rfft_fast_init_f32(&fftInstance.instance, fftLen);
+
+            if (ARM_MATH_SUCCESS != status) {
+                return false;
+            }
+            fftInstance.initialised = true;
+        }
+#else
+        UNUSED(fftLen);
+        UNUSED(fftInstance);
+#endif /* ARM_DSP_AVAILABLE */
+        return true;
+    }
+
+    void MathUtils::FftF32(std::vector<float>& input,
+                           std::vector<float>& fftOutput,
+                           arm::app::math::FftInstance& fftInstance)
+    {
+#if ARM_DSP_AVAILABLE
+        arm_rfft_fast_f32(&fftInstance.instance, input.data(), fftOutput.data(), 0);
+#else
+        UNUSED(fftInstance);
+        const int inputLength = input.size();
+
+        for (int k = 0; k <= inputLength / 2; k++) {
+            float sumReal = 0, sumImag = 0;
+
+            for (int t = 0; t < inputLength; t++) {
+                float angle = 2 * M_PI * t * k / inputLength;
+                sumReal += input[t] * cosf(angle);
+                sumImag += -input[t] * sinf(angle);
+            }
+
+            /* Arrange output to [real0, realN/2, real1, im1, real2, im2, ...] */
+            if (k == 0) {
+                fftOutput[0] = sumReal;
+            } else if (k == inputLength / 2) {
+                fftOutput[1] = sumReal;
+            } else {
+                fftOutput[k*2] = sumReal;
+                fftOutput[k*2 + 1] = sumImag;
+            };
+        }
+#endif /* ARM_DSP_AVAILABLE */
+    }
+
+    void MathUtils::VecLogarithmF32(std::vector <float>& input,
+                                    std::vector <float>& output)
+    {
+#if ARM_DSP_AVAILABLE
+        arm_vlog_f32(input.data(), output.data(),
+                     output.size());
+#else /* ARM_DSP_AVAILABLE */
+        for (auto in = input.begin(), out = output.begin();
+                in != input.end(); ++in, ++out) {
+            *out = logf(*in);
+        }
+#endif /* ARM_DSP_AVAILABLE */
+    }
+
+    float MathUtils::DotProductF32(float* srcPtrA, float* srcPtrB,
+                                   const uint32_t srcLen)
+    {
+        float output = 0.f;
+
+#if ARM_DSP_AVAILABLE
+        arm_dot_prod_f32(srcPtrA, srcPtrB, srcLen, &output);
+#else /* ARM_DSP_AVAILABLE */
+        for (uint32_t i = 0; i < srcLen; ++i) {
+            output += *srcPtrA++ * *srcPtrB++;
+        }
+#endif /* ARM_DSP_AVAILABLE */
+
+        return output;
+    }
+
+    bool MathUtils::ComplexMagnitudeSquaredF32(float* ptrSrc,
+                                               const uint32_t srcLen,
+                                               float* ptrDst,
+                                               const uint32_t dstLen)
+    {
+        if (dstLen < srcLen/2) {
+            printf_err("dstLen must be greater than srcLen/2");
+            return false;
+        }
+
+#if ARM_DSP_AVAILABLE
+        arm_cmplx_mag_squared_f32(ptrSrc, ptrDst, srcLen/2);
+#else /* ARM_DSP_AVAILABLE */
+        for (uint32_t j = 0; j < srcLen; ++j) {
+            const float real = *ptrSrc++;
+            const float im = *ptrSrc++;
+            *ptrDst++ = real*real + im*im;
+        }
+#endif /* ARM_DSP_AVAILABLE */
+        return true;
+    }
+
+} /* namespace math */
+} /* namespace app */
+} /* namespace arm */
\ No newline at end of file
diff --git a/source/application/main/Profiler.cc b/source/application/main/Profiler.cc
new file mode 100644
index 0000000..f364759
--- /dev/null
+++ b/source/application/main/Profiler.cc
@@ -0,0 +1,219 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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.
+ */
+#include "Profiler.hpp"
+
+#include <cstring>
+#include <string>
+#include <sstream>
+
+namespace arm {
+namespace app {
+
+    template<class T>
+    static void writeStatLine(std::ostringstream& s,
+                              const char* desc,
+                              T total,
+                              uint32_t samples,
+                              T min,
+                              T max)
+    {
+        s << "\t" << desc << total << " / "
+          << ((double)total / samples) << " / "
+          << min << " / " << max << std::endl;
+    }
+
+    Profiler::Profiler(hal_platform* platform, const char* name = "Unknown")
+    : _m_name(name)
+    {
+        if (platform && platform->inited) {
+            this->_m_pPlatform = platform;
+            this->Reset();
+        } else {
+            printf_err("Profiler %s initialised with invalid platform\n",
+                this->_m_name.c_str());
+        }
+    }
+
+    bool Profiler::StartProfiling(const char* name)
+    {
+        if (name) {
+            this->SetName(name);
+        }
+        if (this->_m_pPlatform && !this->_m_started) {
+            this->_m_pPlatform->timer->reset();
+            this->_m_tstampSt = this->_m_pPlatform->timer->start_profiling();
+            this->_m_started = true;
+            return true;
+        }
+        printf_err("Failed to start profiler %s\n", this->_m_name.c_str());
+        return false;
+    }
+
+    bool Profiler::StopProfiling()
+    {
+        if (this->_m_pPlatform && this->_m_started) {
+            this->_m_tstampEnd = this->_m_pPlatform->timer->stop_profiling();
+            this->_m_started = false;
+
+            this->_AddProfilingUnit(this->_m_tstampSt, this->_m_tstampEnd, this->_m_name);
+
+            return true;
+        }
+        printf_err("Failed to stop profiler %s\n", this->_m_name.c_str());
+        return false;
+    }
+
+    bool Profiler::StopProfilingAndReset()
+    {
+        if (this->StopProfiling()) {
+            this->Reset();
+            return true;
+        }
+        printf_err("Failed to stop profiler %s\n", this->_m_name.c_str());
+        return false;
+    }
+
+    void Profiler::Reset()
+    {
+        this->_m_started = false;
+        memset(&this->_m_tstampSt, 0, sizeof(this->_m_tstampSt));
+        memset(&this->_m_tstampEnd, 0, sizeof(this->_m_tstampEnd));
+    }
+
+    std::string Profiler::GetResultsAndReset()
+    {
+        std::ostringstream strResults;
+
+        for (const auto& item: this->_m_series) {
+            auto name = item.first;
+            ProfilingSeries series = item.second;
+
+            uint32_t samplesNum = series.size();
+
+            uint64_t totalNpuCycles = 0;        /* Total NPU cycles (idle + active). */
+            uint64_t totalActiveNpuCycles = 0;  /* Active NPU cycles. */
+            uint64_t totalCpuCycles = 0;        /* Total CPU cycles. */
+            time_t totalTimeMs = 0;
+
+            uint64_t minActiveNpuCycles = series[0].activeNpuCycles;
+            uint64_t minIdleNpuCycles = series[0].npuCycles - minActiveNpuCycles;
+            uint64_t minActiveCpuCycles = series[0].cpuCycles - minActiveNpuCycles;
+            time_t minTimeMs = series[0].time;
+
+            uint64_t maxIdleNpuCycles = 0;
+            uint64_t maxActiveNpuCycles = 0;
+            uint64_t maxActiveCpuCycles = 0;
+            time_t maxTimeMs = 0;
+
+            for(ProfilingUnit& unit: series){
+                totalNpuCycles += unit.npuCycles;
+                totalActiveNpuCycles += unit.activeNpuCycles;
+                totalCpuCycles += unit.cpuCycles;
+                totalTimeMs += unit.time;
+
+                maxActiveNpuCycles = std::max(maxActiveNpuCycles,
+                                              unit.activeNpuCycles);
+                maxIdleNpuCycles = std::max(maxIdleNpuCycles,
+                                            unit.npuCycles - maxActiveNpuCycles);
+                maxActiveCpuCycles = std::max(maxActiveCpuCycles,
+                                              unit.cpuCycles - maxActiveNpuCycles);
+                maxTimeMs = std::max(maxTimeMs, unit.time);
+
+                minActiveNpuCycles = std::min(minActiveNpuCycles,
+                                              unit.activeNpuCycles);
+                minIdleNpuCycles = std::min(minIdleNpuCycles,
+                                            unit.npuCycles - minActiveNpuCycles);
+                minActiveCpuCycles = std::min(minActiveCpuCycles,
+                                              unit.cpuCycles - minActiveNpuCycles);
+                minTimeMs = std::min(minTimeMs, unit.time);
+            }
+
+            strResults << "Profile for " << name << ": " << std::endl;
+
+            if (samplesNum > 1) {
+                strResults << "\tSamples: " << samplesNum << std::endl;
+                strResults << "\t                            Total / Avg./ Min / Max"
+                           << std::endl;
+
+                writeStatLine<uint64_t>(strResults, "Active NPU cycles:          ",
+                                        totalActiveNpuCycles, samplesNum,
+                                        minActiveNpuCycles, maxActiveNpuCycles);
+
+                writeStatLine<uint64_t>(strResults, "Idle NPU cycles:            ",
+                                        (totalNpuCycles - totalActiveNpuCycles),
+                                        samplesNum, minIdleNpuCycles, maxIdleNpuCycles);
+
+#if defined(CPU_PROFILE_ENABLED)
+                writeStatLine<uint64_t>(strResults, "Active CPU cycles (approx): ",
+                                        (totalCpuCycles - totalActiveNpuCycles),
+                                        samplesNum, minActiveCpuCycles,
+                                        maxActiveCpuCycles);
+
+                writeStatLine<time_t>(strResults, "Time in ms:                 ",
+                                        totalTimeMs, samplesNum, minTimeMs, maxTimeMs);
+#endif
+            } else {
+                strResults << "\tActive NPU cycles: " << totalActiveNpuCycles
+                           << std::endl;
+                strResults << "\tIdle NPU cycles:   "
+                           << (totalNpuCycles - totalActiveNpuCycles)
+                           << std::endl;
+#if defined(CPU_PROFILE_ENABLED)
+                strResults << "\tActive CPU cycles: "
+                           << (totalCpuCycles - totalActiveNpuCycles)
+                           << " (approx)" << std::endl;
+
+                strResults << "\tTime in ms:        " << totalTimeMs << std::endl;
+#endif
+            }
+        }
+        this->Reset();
+        return strResults.str();
+    }
+
+    void Profiler::SetName(const char* str)
+    {
+        this->_m_name = std::string(str);
+    }
+
+    void Profiler::_AddProfilingUnit(time_counter start, time_counter end,
+                                     const std::string& name)
+    {
+        platform_timer * timer = this->_m_pPlatform->timer;
+
+        struct ProfilingUnit unit;
+
+        if (timer->cap.npu_cycles && timer->get_npu_total_cycle_diff &&
+            timer->get_npu_active_cycle_diff)
+        {
+            unit.npuCycles = timer->get_npu_total_cycle_diff(&start, &end);
+            unit.activeNpuCycles = timer->get_npu_active_cycle_diff(&start, &end);
+        }
+
+        if (timer->cap.cpu_cycles && timer->get_cpu_cycle_diff) {
+            unit.cpuCycles = timer->get_cpu_cycle_diff(&start, &end);
+        }
+
+        if (timer->cap.duration_ms && timer->get_duration_ms) {
+            unit.time = timer->get_duration_ms(&start, &end);
+        }
+
+        this->_m_series[name].emplace_back(unit);
+    }
+
+} /* namespace app */
+} /* namespace arm */
\ No newline at end of file
diff --git a/source/application/main/UseCaseCommonUtils.cc b/source/application/main/UseCaseCommonUtils.cc
new file mode 100644
index 0000000..4ea5e4d
--- /dev/null
+++ b/source/application/main/UseCaseCommonUtils.cc
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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.
+ */
+#include "UseCaseCommonUtils.hpp"
+
+#include "InputFiles.hpp"
+
+namespace arm {
+namespace app {
+
+    bool RunInference(hal_platform& platform, arm::app::Model& model)
+    {
+        Profiler profiler{&platform, "Inference"};
+        profiler.StartProfiling();
+
+        bool runInf = model.RunInference();
+
+        profiler.StopProfiling();
+        std::string profileResults = profiler.GetResultsAndReset();
+        info("%s\n", profileResults.c_str());
+
+        return runInf;
+    }
+
+    int ReadUserInputAsInt(hal_platform& platform)
+    {
+        char chInput[128];
+        memset(chInput, 0, sizeof(chInput));
+
+        platform.data_acq->get_input(chInput, sizeof(chInput));
+        return atoi(chInput);
+    }
+
+    void DumpTensor(TfLiteTensor* tensor, const size_t lineBreakForNumElements)
+    {
+        char strhex[8];
+        std::string strdump;
+
+        if (!tensor) {
+            printf_err("invalid tensor\n");
+            return;
+        }
+
+        const uint32_t tensorSz = tensor->bytes;
+        const uint8_t* tensorData = tflite::GetTensorData<uint8_t>(tensor);
+
+        for (size_t i = 0; i < tensorSz; ++i) {
+            if (0 == i % lineBreakForNumElements) {
+                printf("%s\n\t", strdump.c_str());
+                strdump.clear();
+            }
+            snprintf(strhex, sizeof(strhex) - 1,
+                     "0x%02x, ", tensorData[i]);
+            strdump += std::string(strhex);
+        }
+
+        if (strdump.size()) {
+            printf("%s\n", strdump.c_str());
+        }
+    }
+
+    bool ListFilesHandler(ApplicationContext& ctx)
+    {
+        auto& model = ctx.Get<Model&>("model");
+        auto& platform = ctx.Get<hal_platform&>("platform");
+
+        constexpr uint32_t dataPsnTxtStartX = 20;
+        constexpr uint32_t dataPsnTxtStartY = 40;
+
+        if (!model.IsInited()) {
+            printf_err("Model is not initialised! Terminating processing.\n");
+            return false;
+        }
+
+        /* Clear the LCD */
+        platform.data_psn->clear(COLOR_BLACK);
+
+        /* Show the total number of embedded files. */
+        std::string strNumFiles = std::string{"Total Number of Files: "} +
+                                   std::to_string(NUMBER_OF_FILES);
+        platform.data_psn->present_data_text(strNumFiles.c_str(),
+                                             strNumFiles.size(),
+                                             dataPsnTxtStartX,
+                                             dataPsnTxtStartY,
+                                             0);
+
+#if NUMBER_OF_FILES > 0
+        constexpr uint32_t dataPsnTxtYIncr = 16;
+        info("List of Files:\n");
+        uint32_t yVal = dataPsnTxtStartY + dataPsnTxtYIncr;
+        for (uint32_t i = 0; i < NUMBER_OF_FILES; ++i, yVal += dataPsnTxtYIncr) {
+
+            std::string currentFilename{get_filename(i)};
+            platform.data_psn->present_data_text(currentFilename.c_str(),
+                                                 currentFilename.size(),
+                                                 dataPsnTxtStartX, yVal, 0);
+
+            info("\t%u => %s\n", i, currentFilename.c_str());
+        }
+#endif /* NUMBER_OF_FILES > 0 */
+
+        return true;
+    }
+
+} /* namespace app */
+} /* namespace arm */
\ No newline at end of file
diff --git a/source/application/main/include/AppContext.hpp b/source/application/main/include/AppContext.hpp
new file mode 100644
index 0000000..588dfaa
--- /dev/null
+++ b/source/application/main/include/AppContext.hpp
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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 APP_CTX_HPP
+#define APP_CTX_HPP
+
+#include <string>
+#include <map>
+
+namespace arm {
+namespace app {
+
+    class IAttribute
+    {
+    public:
+        virtual ~IAttribute() = default;
+    };
+
+    template<typename T>
+    class Attribute : public IAttribute
+    {
+    public:
+        ~Attribute() override = default;
+
+        explicit Attribute(const T value): _m_value(value){}
+
+        T Get()
+        {
+            return _m_value;
+        }
+    private:
+        T _m_value;
+    };
+
+    /* Application context class */
+    class ApplicationContext {
+    public:
+
+        /**
+         * @brief     Saves given value as a named attribute in the context.
+         * @tparam    T value type.
+         * @param[in] name     Context attribute name.
+         * @param[in] object   Value to save in the context.
+         */
+        template<typename T>
+        void Set(const std::string &name, T object)
+        {
+            this->_m_attributes[name] = new Attribute<T>(object);
+        }
+
+        /**
+         * @brief      Gets the saved attribute from the context by the given name.
+         * @tparam     T value type.
+         * @param[in]  name   Context attribute name.
+         * @return     Value saved in the context.
+         */
+        template<typename T>
+        T Get(const std::string &name)
+        {
+            auto a = (Attribute<T>*)_m_attributes[name];
+            return a->Get();
+        }
+
+        /**
+         * @brief      Checks if an attribute for a given name exists in the context.
+         * @param[in]  name   Attribute name.
+         * @return     true if attribute exists, false otherwise
+         */
+        bool Has(const std::string& name)
+        {
+            return _m_attributes.find(name) != _m_attributes.end();
+        }
+
+        ApplicationContext() = default;
+
+        ~ApplicationContext() {
+            for (auto& attribute : _m_attributes)
+                delete attribute.second;
+
+            this->_m_attributes.clear();
+        }
+    private:
+        std::map<std::string, IAttribute*> _m_attributes;
+    };
+
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* APP_CTX_HPP */
diff --git a/source/application/main/include/AudioUtils.hpp b/source/application/main/include/AudioUtils.hpp
new file mode 100644
index 0000000..cba981d
--- /dev/null
+++ b/source/application/main/include/AudioUtils.hpp
@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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 AUDIO_UTILS_HPP
+#define AUDIO_UTILS_HPP
+
+#include <cstddef>
+#include <cstdint>
+
+namespace arm {
+namespace app {
+namespace audio {
+
+    template<class T>
+    class SlidingWindow {
+    public:
+
+        /**
+         * @brief     Creates the window slider through the given data.
+         *
+         * @param[in] data         Pointer to the data to slide through.
+         * @param[in] dataSize     Size in T type elements wise.
+         * @param[in] windowSize   Sliding window size in T type wise elements.
+         * @param[in] stride       Stride size in T type wise elements.
+         */
+        SlidingWindow(T *data, size_t dataSize,
+                      size_t windowSize, size_t stride) {
+            m_start = data;
+            m_dataSize = dataSize;
+            m_size = windowSize;
+            m_stride = stride;
+        }
+
+        SlidingWindow() = default;
+
+        ~SlidingWindow() = default;
+
+        /**
+         * @brief  Get the next data window.
+         * @return Pointer to the next window, if next window is not available nullptr is returned.
+         */
+        virtual T *Next() {
+            if (HasNext()) {
+                m_count++;
+                return m_start + Index() * m_stride;
+            } else {
+                return nullptr;
+            }
+        }
+
+        /**
+         * @brief  Checks if the next data portion is available.
+         * @return true if next data portion is available.
+         */
+        virtual bool HasNext() {
+            return m_size + m_count * m_stride <= m_dataSize;
+        }
+
+        /**
+         * @brief Reset the slider to the initial position.
+         */
+        virtual void Reset() {
+            m_count = 0;
+        }
+
+        /**
+         * @brief     Resets the slider to the start of the new data.
+         *            New data size MUST be the same as the old one.
+         * @param[in] newStart   Pointer to the new data to slide through.
+         */
+        virtual void Reset(T *newStart) {
+            m_start = newStart;
+            Reset();
+        }
+
+        /**
+         * @brief  Gets current index of the sliding window.
+         * @return Current position of the sliding window in number of strides.
+         */
+        size_t Index() {
+            return m_count == 0? 0: m_count - 1;
+        }
+
+        /**
+         * @brief  Gets the index from the start of the data where the next window will begin.
+         *         While Index() returns the index of sliding window itself this function
+         *         returns the index of the data element itself.
+         * @return Index from the start of the data where the next sliding window will begin.
+         */
+        virtual uint32_t NextWindowStartIndex() {
+            return m_count == 0? 0: ((m_count) * m_stride);
+        }
+
+        /**
+         * @brief     Go to given sliding window index.
+         * @param[in] index   New position of the sliding window. If index is invalid
+         *                    (greater than possible range of strides) then next call to Next() will return nullptr.
+         */
+        void FastForward(size_t index) {
+            m_count = index;
+        }
+
+        /**
+         * @brief  Calculates whole number of times the window can stride through the given data.
+         * @return Maximum number of whole strides.
+         */
+         size_t TotalStrides() {
+            if (m_size > m_dataSize) {
+                return 0;
+            }
+            return ((m_dataSize - m_size)/m_stride);
+        }
+
+        /**
+         * @brief  Calculates number of times the window can stride through the given data.
+         *         May not be a whole number.
+         * @return Number of strides to cover all data.
+         */
+        float FractionalTotalStrides() {
+            if (this->m_dataSize < this->m_size) {
+                return 0;
+            } else {
+                return ((this->m_dataSize - this->m_size)/ static_cast<float>(this->m_stride));
+            }
+        }
+
+    protected:
+        T *m_start = nullptr;
+        size_t m_dataSize = 0;
+        size_t m_size = 0;
+        size_t m_stride = 0;
+        size_t m_count = 0;
+    };
+
+    /*
+     * Sliding window for ASR will cover the whole of the input, even if
+     * this means the last window is not a full window length.
+     */
+    template<class T>
+    class ASRSlidingWindow : public SlidingWindow<T> {
+    public:
+        using SlidingWindow<T>::SlidingWindow;
+
+        /**
+         * @brief  Checks if the next data portion is available.
+         * @return true if next data portion is available.
+         */
+        bool HasNext() {
+            return this->m_count < 1 + this->FractionalTotalStrides() && (this->NextWindowStartIndex() < this->m_dataSize);
+        }
+    };
+
+
+} /* namespace audio */
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* AUDIO_UTILS_HPP */
\ No newline at end of file
diff --git a/source/application/main/include/ClassificationResult.hpp b/source/application/main/include/ClassificationResult.hpp
new file mode 100644
index 0000000..eae28e4
--- /dev/null
+++ b/source/application/main/include/ClassificationResult.hpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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 CLASSIFICATION_RESULT_HPP
+#define CLASSIFICATION_RESULT_HPP
+
+#include <string>
+
+namespace arm {
+namespace app {
+
+    /**
+     * @brief   Class representing a single classification result.
+     */
+    class ClassificationResult {
+    public:
+        double          m_normalisedVal = 0.0;
+        std::string     m_label;
+        uint32_t        m_labelIdx = 0;
+
+        ClassificationResult() = default;
+        ~ClassificationResult() = default;
+    };
+
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* CLASSIFICATION_RESULT_HPP */
\ No newline at end of file
diff --git a/source/application/main/include/Classifier.hpp b/source/application/main/include/Classifier.hpp
new file mode 100644
index 0000000..510e6f9
--- /dev/null
+++ b/source/application/main/include/Classifier.hpp
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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 CLASSIFIER_HPP
+#define CLASSIFIER_HPP
+
+#include "ClassificationResult.hpp"
+#include "TensorFlowLiteMicro.hpp"
+
+#include <vector>
+
+namespace arm {
+namespace app {
+
+    /**
+     * @brief   Classifier - a helper class to get certain number of top
+     *          results from the output vector from a classification NN.
+     **/
+    class Classifier{
+    public:
+        /** @brief Constructor. */
+        Classifier() = default;
+
+        /**
+         * @brief       Gets the top N classification results from the
+         *              output vector.
+         * @param[in]   outputTensor   Inference output tensor from an NN model.
+         * @param[out]  vecResults     A vector of classification results.
+         *                             populated by this function.
+         * @param[in]   labels         Labels vector to match classified classes.
+         * @param[in]   topNCount      Number of top classifications to pick. Default is 1.
+         * @return      true if successful, false otherwise.
+         **/
+        virtual bool GetClassificationResults(
+            TfLiteTensor* outputTensor,
+            std::vector<ClassificationResult>& vecResults,
+            const std::vector <std::string>& labels, uint32_t topNCount);
+
+    private:
+        /**
+         * @brief       Utility function that gets the top N classification results from the
+         *              output vector.
+         * @tparam T value type
+         * @param[in]   tensor       Inference output tensor from an NN model.
+         * @param[out]  vecResults   A vector of classification results
+         *                           populated by this function.
+         * @param[in]   topNCount    Number of top classifications to pick.
+         * @param[in]   labels       Labels vector to match classified classes.
+         * @return      true if successful, false otherwise.
+         **/
+        template<typename T>
+        bool _GetTopNResults(TfLiteTensor* tensor,
+                            std::vector<ClassificationResult>& vecResults,
+                            uint32_t topNCount,
+                            const std::vector <std::string>& labels);
+    };
+
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* CLASSIFIER_HPP */
diff --git a/source/application/main/include/DataStructures.hpp b/source/application/main/include/DataStructures.hpp
new file mode 100644
index 0000000..5cc8b5e
--- /dev/null
+++ b/source/application/main/include/DataStructures.hpp
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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 DATA_STRUCTURES_HPP
+#define DATA_STRUCTURES_HPP
+
+#include "hal.h"
+
+#include <iterator>
+
+namespace arm {
+namespace app {
+
+    /**
+     * Class Array2d is a data structure that represents a two dimensional array.
+     * The data is allocated in contiguous memory, arranged row-wise
+     * and individual elements can be accessed with the () operator.
+     * For example a two dimensional array D of size (M, N) can be accessed:
+     *
+     *               _|<------------- col size = N  -------->|
+     *               |  D(r=0, c=0) D(r=0, c=1)... D(r=0, c=N)
+     *               |  D(r=1, c=0) D(r=1, c=1)... D(r=1, c=N)
+     *               |  ...
+     *    row size = M  ...
+     *               |  ...
+     *               _  D(r=M, c=0) D(r=M, c=1)... D(r=M, c=N)
+     *
+     */
+    template<typename T>
+    class Array2d {
+    public:
+        /**
+         * @brief     Creates the array2d with the given sizes.
+         * @param[in] rows   Number of rows.
+         * @param[in] cols   Number of columns.
+         */
+        Array2d(unsigned rows, unsigned cols)
+        {
+            if (rows == 0 || cols == 0) {
+                printf_err("Array2d constructor has 0 size.\n");
+                _m_data = nullptr;
+                return;
+            }
+            _m_rows = rows;
+            _m_cols = cols;
+            _m_data = new T[rows * cols];
+        }
+
+        ~Array2d()
+        {
+            delete[] _m_data;
+        }
+
+        T& operator() (unsigned int row, unsigned int col)
+        {
+#if defined(DEBUG)
+            if (row >= _m_rows || col >= _m_cols ||  _m_data == nullptr) {
+                printf_err("Array2d subscript out of bounds.\n");
+            }
+#endif /* defined(DEBUG) */
+            return _m_data[_m_cols * row + col];
+        }
+
+        T operator() (unsigned int row, unsigned int col) const
+        {
+#if defined(DEBUG)
+            if (row >= _m_rows || col >= _m_cols ||  _m_data == nullptr) {
+                printf_err("const Array2d subscript out of bounds.\n");
+            }
+#endif /* defined(DEBUG) */
+            return _m_data[_m_cols * row + col];
+        }
+
+        /**
+         * @brief  Gets rows number of the current array2d.
+         * @return Number of rows.
+         */
+        size_t size(size_t dim)
+        {
+            switch (dim)
+            {
+                case 0:
+                    return _m_rows;
+                case 1:
+                    return _m_cols;
+                default:
+                    return 0;
+            }
+        }
+
+        /**
+         * @brief Gets the array2d total size.
+         */
+        size_t totalSize()
+        {
+            return _m_rows * _m_cols;
+        }
+
+        /**
+         * array2d iterator.
+         */
+        using iterator=T*;
+        using const_iterator=T const*;
+
+        iterator begin() { return _m_data; }
+        iterator end() { return _m_data + totalSize(); }
+        const_iterator begin() const { return _m_data; }
+        const_iterator end() const { return _m_data + totalSize(); };
+
+    private:
+        size_t _m_rows;
+        size_t _m_cols;
+        T* _m_data;
+    };
+
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* DATA_STRUCTURES_HPP */
\ No newline at end of file
diff --git a/source/application/main/include/Mfcc.hpp b/source/application/main/include/Mfcc.hpp
new file mode 100644
index 0000000..6379fab
--- /dev/null
+++ b/source/application/main/include/Mfcc.hpp
@@ -0,0 +1,255 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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 MFCC_HPP
+#define MFCC_HPP
+
+#include "PlatformMath.hpp"
+
+#include <vector>
+#include <cstdint>
+#include <cmath>
+#include <limits>
+#include <string>
+
+namespace arm {
+namespace app {
+namespace audio {
+
+    /* MFCC's consolidated parameters. */
+    class MfccParams {
+    public:
+        float       m_samplingFreq;
+        uint32_t    m_numFbankBins;
+        float       m_melLoFreq;
+        float       m_melHiFreq;
+        uint32_t    m_numMfccFeatures;
+        uint32_t    m_frameLen;
+        uint32_t    m_frameLenPadded;
+        bool        m_useHtkMethod;
+
+        /** @brief  Constructor */
+        MfccParams(float samplingFreq, uint32_t numFbankBins,
+                   float melLoFreq, float melHiFreq,
+                   uint32_t numMfccFeats, uint32_t frameLen,
+                   bool useHtkMethod);
+
+        MfccParams()  = delete;
+
+        ~MfccParams() = default;
+
+        /** @brief  String representation of parameters */
+        std::string Str();
+    };
+
+    /**
+     * @brief   Class for MFCC feature extraction.
+     *          Based on https://github.com/ARM-software/ML-KWS-for-MCU/blob/master/Deployment/Source/MFCC/mfcc.cpp
+     *          This class is designed to be generic and self-sufficient but
+     *          certain calculation routines can be overridden to accommodate
+     *          use-case specific requirements.
+     */
+    class MFCC {
+    public:
+        /**
+         * @brief       Constructor
+         * @param[in]   params   MFCC parameters
+        */
+        explicit MFCC(const MfccParams& params);
+
+        MFCC() = delete;
+
+        ~MFCC() = default;
+
+        /**
+        * @brief        Extract MFCC  features for one single small frame of
+        *               audio data e.g. 640 samples.
+        * @param[in]    audioData   Vector of audio samples to calculate
+        *                           features for.
+        * @return       Vector of extracted MFCC features.
+        **/
+        std::vector<float> MfccCompute(const std::vector<int16_t>& audioData);
+
+        /** @brief  Initialise. */
+        void Init();
+
+       /**
+        * @brief        Extract MFCC features and quantise for one single small
+        *               frame of audio data e.g. 640 samples.
+        * @param[in]    audioData     Vector of audio samples to calculate
+        *                             features for.
+        * @param[in]    quantScale    Quantisation scale.
+        * @param[in]    quantOffset   Quantisation offset.
+        * @return       Vector of extracted quantised MFCC features.
+        **/
+        template<typename T>
+        std::vector<T> MfccComputeQuant(const std::vector<int16_t>& audioData,
+                                        const float quantScale,
+                                        const int quantOffset)
+        {
+            this->_MfccComputePreFeature(audioData);
+            float minVal = std::numeric_limits<T>::min();
+            float maxVal = std::numeric_limits<T>::max();
+
+            std::vector<T> mfccOut(this->_m_params.m_numMfccFeatures);
+            const size_t numFbankBins = this->_m_params.m_numFbankBins;
+
+            /* Take DCT. Uses matrix mul. */
+            for (size_t i = 0, j = 0; i < mfccOut.size(); ++i, j += numFbankBins) {
+                float sum = 0;
+                for (size_t k = 0; k < numFbankBins; ++k) {
+                    sum += this->_m_dctMatrix[j + k] * this->_m_melEnergies[k];
+                }
+                /* Quantize to T. */
+                sum = std::round((sum / quantScale) + quantOffset);
+                mfccOut[i] = static_cast<T>(std::min<float>(std::max<float>(sum, minVal), maxVal));
+            }
+
+            return mfccOut;
+        }
+
+        /* Constants */
+        static constexpr float ms_logStep = /*logf(6.4)*/ 1.8562979903656 / 27.0;
+        static constexpr float ms_freqStep = 200.0 / 3;
+        static constexpr float ms_minLogHz = 1000.0;
+        static constexpr float ms_minLogMel = ms_minLogHz / ms_freqStep;
+
+    protected:
+        /**
+         * @brief       Project input frequency to Mel Scale.
+         * @param[in]   freq           Input frequency in floating point.
+         * @param[in]   useHTKmethod   bool to signal if HTK method is to be
+         *                             used for calculation.
+         * @return      Mel transformed frequency in floating point.
+         **/
+        static float MelScale(float freq,
+                              bool  useHTKMethod = true);
+
+        /**
+         * @brief       Inverse Mel transform - convert MEL warped frequency
+         *              back to normal frequency.
+         * @param[in]   freq           Mel frequency in floating point.
+         * @param[in]   useHTKmethod   bool to signal if HTK method is to be
+         *                             used for calculation.
+         * @return      Real world frequency in floating point.
+         **/
+        static float InverseMelScale(float melFreq,
+                                     bool  useHTKMethod = true);
+
+        /**
+         * @brief       Populates MEL energies after applying the MEL filter
+         *              bank weights and adding them up to be placed into
+         *              bins, according to the filter bank's first and last
+         *              indices (pre-computed for each filter bank element
+         *              by _CreateMelFilterBank function).
+         * @param[in]   fftVec                  Vector populated with FFT magnitudes.
+         * @param[in]   melFilterBank           2D Vector with filter bank weights.
+         * @param[in]   filterBankFilterFirst   Vector containing the first indices of filter bank
+         *                                      to be used for each bin.
+         * @param[in]   filterBankFilterLast    Vector containing the last indices of filter bank
+         *                                      to be used for each bin.
+         * @param[out]  melEnergies             Pre-allocated vector of MEL energies to be
+         *                                      populated.
+         * @return      true if successful, false otherwise.
+         */
+        virtual bool ApplyMelFilterBank(
+            std::vector<float>&                 fftVec,
+            std::vector<std::vector<float>>&    melFilterBank,
+            std::vector<int32_t>&               filterBankFilterFirst,
+            std::vector<int32_t>&               filterBankFilterLast,
+            std::vector<float>&                 melEnergies);
+
+        /**
+         * @brief           Converts the Mel energies for logarithmic scale.
+         * @param[in,out]   melEnergies   1D vector of Mel energies.
+         **/
+        virtual void ConvertToLogarithmicScale(std::vector<float>& melEnergies);
+
+        /**
+         * @brief       Create a matrix used to calculate Discrete Cosine
+         *              Transform.
+         * @param[in]   inputLength        Input length of the buffer on which
+         *                                 DCT will be performed.
+         * @param[in]   coefficientCount   Total coefficients per input length.
+         * @return      1D vector with inputLength x coefficientCount elements
+         *              populated with DCT coefficients.
+         */
+        virtual std::vector<float> CreateDCTMatrix(
+                                    int32_t inputLength,
+                                    int32_t coefficientCount);
+
+        /**
+         * @brief       Given the low and high Mel values, get the normaliser
+         *              for weights to be applied when populating the filter
+         *              bank.
+         * @param[in]   leftMel        Low Mel frequency value.
+         * @param[in]   rightMel       High Mel frequency value.
+         * @param[in]   useHTKMethod   bool to signal if HTK method is to be
+         *                             used for calculation.
+         * @return      Value to use for normalizing.
+         */
+        virtual float GetMelFilterBankNormaliser(
+                        const float&   leftMel,
+                        const float&   rightMel,
+                        bool     useHTKMethod);
+
+    private:
+        MfccParams                      _m_params;
+        std::vector<float>              _m_frame;
+        std::vector<float>              _m_buffer;
+        std::vector<float>              _m_melEnergies;
+        std::vector<float>              _m_windowFunc;
+        std::vector<std::vector<float>> _m_melFilterBank;
+        std::vector<float>              _m_dctMatrix;
+        std::vector<int32_t>            _m_filterBankFilterFirst;
+        std::vector<int32_t>            _m_filterBankFilterLast;
+        bool                            _m_filterBankInitialised;
+        arm::app::math::FftInstance     _m_fftInstance;
+
+        /**
+         * @brief       Initialises the filter banks and the DCT matrix. **/
+        void _InitMelFilterBank();
+
+        /**
+         * @brief       Signals whether the instance of MFCC has had its
+         *              required buffers initialised.
+         * @return      true if initialised, false otherwise.
+         **/
+        bool _IsMelFilterBankInited();
+
+        /**
+         * @brief       Create mel filter banks for MFCC calculation.
+         * @return      2D vector of floats.
+         **/
+        std::vector<std::vector<float>> _CreateMelFilterBank();
+
+        /**
+         * @brief       Computes and populates internal memeber buffers used
+         *              in MFCC feature calculation
+         * @param[in]   audioData   1D vector of 16-bit audio data.
+         */
+        void _MfccComputePreFeature(const std::vector<int16_t>& audioData);
+
+        /** @brief       Computes the magnitude from an interleaved complex array. */
+        void _ConvertToPowerSpectrum();
+
+    };
+
+} /* namespace audio */
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* MFCC_HPP */
\ No newline at end of file
diff --git a/source/application/main/include/PlatformMath.hpp b/source/application/main/include/PlatformMath.hpp
new file mode 100644
index 0000000..45e6a9e
--- /dev/null
+++ b/source/application/main/include/PlatformMath.hpp
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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 PLATFORM_MATH_HPP
+#define PLATFORM_MATH_HPP
+
+#include "hal.h"
+
+/* See if ARM DSP functions can be used. */
+#if PLATFORM_HAL == PLATFORM_CORTEX_M_BAREMETAL
+    #if defined(__DSP_PRESENT) && (__DSP_PRESENT == 1U)
+
+        #define ARM_DSP_AVAILABLE   (1U)
+        #include "arm_math.h"
+        #define M_PI    (PI)
+
+    #endif /* defined(__DSP_PRESENT) && (__DSP_PRESENT == 1U) */
+#endif /* PLATFORM_HAL == PLATFORM_CORTEX_M_BAREMETAL */
+
+#include <vector>
+
+namespace arm {
+namespace app {
+namespace math {
+
+    struct FftInstance {
+#if ARM_DSP_AVAILABLE
+        arm_rfft_fast_instance_f32 instance;
+#endif
+        bool initialised = false;
+    };
+
+    /* Class to provide Math functions like FFT, mean, stddev etc.
+     * This will allow other classes, functions to be independent of
+     * #if definition checks and provide a cleaner API. Also, it will
+     * consolidate all arm math functions used in one place and make
+     * them easier to test. */
+    class MathUtils {
+
+    public:
+        /**
+         * @brief       Get the cosine value of the argument in floating point.
+         * @param[in]   radians   Angle in radians.
+         * @return      Cosine value (floating point).
+         */
+        static float CosineF32(float radians);
+
+        /**
+         * @brief       Get the square root of the argument in floating point.
+         * @param[in]   input   Value to compute square root of.
+         * @return      Square root (floating point) value.
+         */
+        static float SqrtF32(float input);
+
+        /**
+         * @brief       Gets the mean of a floating point array of elements.
+         * @param[in]   ptrSrc   Pointer to the first element.
+         * @param[in]   srcLen   Number of elements in the array/vector.
+         * @return      Average value.
+         */
+        static float MeanF32(float* ptrSrc, uint32_t srcLen);
+
+        /**
+         * @brief       Gets the standard deviation of a floating point array
+         *              of elements.
+         * @param[in]   ptrSrc   Pointer to the first element.
+         * @param[in]   srcLen   Number of elements in the array/vector.
+         * @param[in]   mean     Pre-computed mean value.
+         * @return      Standard deviation value.
+         */
+        static float StdDevF32(float* ptrSrc, uint32_t srcLen,
+                               float mean);
+
+        /**
+         * @brief       Initialises the internal FFT structures (if available
+         *              for the platform). This function should be called
+         *              prior to Fft32 function call if built with ARM DSP functions.
+         * @param[in]   fftLen        Requested length of the FFT.
+         * @param[in]   fftInstance   FFT instance struct to use.
+         * @return      true if successful, false otherwise.
+         */
+        static bool FftInitF32(const uint16_t fftLen, arm::app::math::FftInstance& fftInstance);
+
+        /**
+         * @brief       Computes the FFT for the input vector.
+         * @param[in]   input       Floating point vector of input elements
+         * @param[out]  fftOutput   Output buffer to be populated by computed FFTs.
+         * @param[in]   fftInstance FFT instance struct to use.
+         */
+        static void FftF32(std::vector<float>& input,
+                           std::vector<float>& fftOutput,
+                           arm::app::math::FftInstance& fftInstance);
+
+        /**
+         * @brief       Computes the natural logarithms of input floating point
+         *              vector
+         * @param[in]   input    Floating point input vector
+         * @param[out]  output   Pre-allocated buffer to be populated with
+         *                       natural log values of each input element.
+         */
+        static void VecLogarithmF32(std::vector <float>& input,
+                                    std::vector <float>& output);
+
+        /**
+         * @brief       Computes the dot product of two 1D floating point
+         *              vectors.
+         *              result = sum(srcA[0]*srcB[0] + srcA[1]*srcB[1] + ..)
+         * @param[in]   srcPtrA   Pointer to the first element of first
+         *                        array.
+         * @param[in]   srcPtrB   Pointer to the first element of second
+         *                        array.
+         * @param[in]   srcLen    Number of elements in the array/vector.
+         * @return      Dot product.
+         */
+        static float DotProductF32(float* srcPtrA, float* srcPtrB,
+                                   const uint32_t srcLen);
+
+        /**
+         * @brief       Computes the squared magnitude of floating point
+         *              complex number array.
+         * @param[in]   ptrSrc   Pointer to the first element of input
+         *                       array.
+         * @param[in]   srcLen   Number of elements in the array/vector.
+         * @param[out]  ptrDst   Output buffer to be populated.
+         * @param[in]   dstLen   Output buffer len (for sanity check only).
+         * @return      true if successful, false otherwise.
+         */
+        static bool ComplexMagnitudeSquaredF32(float* ptrSrc,
+                                               const uint32_t srcLen,
+                                               float* ptrDst,
+                                               const uint32_t dstLen);
+
+    };
+} /* namespace math */
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* PLATFORM_MATH_HPP */
\ No newline at end of file
diff --git a/source/application/main/include/Profiler.hpp b/source/application/main/include/Profiler.hpp
new file mode 100644
index 0000000..b16a63b
--- /dev/null
+++ b/source/application/main/include/Profiler.hpp
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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 APP_PROFILER_HPP
+#define APP_PROFILER_HPP
+
+#include "hal.h"
+
+#include <string>
+#include <map>
+#include <vector>
+
+namespace arm {
+namespace app {
+
+    /** A single profiling unit definition. */
+    struct ProfilingUnit {
+        uint64_t npuCycles = 0;
+        uint64_t activeNpuCycles = 0;
+        uint64_t cpuCycles = 0;
+        time_t time = 0;
+    };
+
+    /* A collection of profiling units. */
+    using ProfilingSeries = std::vector<arm::app::ProfilingUnit>;
+
+    /* A map for string identifiable profiling series. */
+    using ProfilingMap = std::map<std::string, ProfilingSeries>;
+
+    /**
+     * @brief   A very simple profiler example using the platform timer
+     *          implementation.
+     */
+    class Profiler {
+    public:
+        /**
+         * @brief       Constructor for profiler.
+         * @param[in]   platform   Pointer to a valid, initialised hal platform.
+         * @param[in]   name       A friendly name for this profiler.
+         **/
+        Profiler(hal_platform* platform, const char* name);
+
+        /** Block the default constructor. */
+        Profiler() = delete;
+
+        /** Default destructor. */
+        ~Profiler() = default;
+
+        /** @brief  Start profiling => get starting time-stamp. */
+        bool StartProfiling(const char* name = nullptr);
+
+        /** @brief  Stop profiling => get the ending time-stamp. */
+        bool StopProfiling();
+
+        /** @brief  Stops the profiling and internally resets the
+         *          platform timers. */
+        bool StopProfilingAndReset();
+
+        /** @brief  Reset the platform timers. */
+        void Reset();
+
+        /**
+         * @brief   Gets the results as string and resets the profiler.
+         * @returns Result string.
+         **/
+        std::string GetResultsAndReset();
+
+        /** @brief Set the profiler name. */
+        void SetName(const char* str);
+
+    private:
+        ProfilingMap    _m_series;                /* Profiling series map. */
+        time_counter    _m_tstampSt;              /* Container for a current starting timestamp. */
+        time_counter    _m_tstampEnd;             /* Container for a current ending timestamp. */
+        hal_platform *  _m_pPlatform = nullptr;   /* Platform pointer - to get the timer. */
+
+        bool            _m_started = false;       /* Indicates profiler has been started. */
+
+        std::string     _m_name;                  /* Name given to this profiler. */
+
+        /**
+         * @brief       Appends the profiling unit computed by the "start" and
+         *              "end" timestamps to the profiling series identified by
+         *              the name provided.
+         * @param[in]   start   Starting time-stamp.
+         * @param[in]   end     Ending time-stamp.
+         * @param[in]   name    Name for the profiling unit series to be
+         *                      appended to.
+         **/
+        void _AddProfilingUnit(time_counter start, time_counter end,
+                               const std::string& name);
+    };
+
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* APP_PROFILER_HPP */
diff --git a/source/application/main/include/UseCaseCommonUtils.hpp b/source/application/main/include/UseCaseCommonUtils.hpp
new file mode 100644
index 0000000..02200e8
--- /dev/null
+++ b/source/application/main/include/UseCaseCommonUtils.hpp
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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 USECASE_COMMON_UTILS_HPP
+#define USECASE_COMMON_UTILS_HPP
+
+#include "hal.h"
+#include "Model.hpp"
+#include "AppContext.hpp"
+#include "Profiler.hpp"
+
+/* Helper macro to convert RGB888 to RGB565 format. */
+#define RGB888_TO_RGB565(R8,G8,B8)  ((((R8>>3) & 0x1F) << 11) |     \
+                                     (((G8>>2) & 0x3F) << 5)  |     \
+                                     ((B8>>3) & 0x1F))
+
+constexpr uint16_t COLOR_BLACK  = 0;
+constexpr uint16_t COLOR_GREEN  = RGB888_TO_RGB565(  0, 255,  0); // 2016;
+constexpr uint16_t COLOR_YELLOW = RGB888_TO_RGB565(255, 255,  0); // 65504;
+
+namespace arm {
+namespace app {
+
+    /**
+     * @brief           Run inference using given model
+     *                  object. If profiling is enabled, it will log the
+     *                  statistics too.
+     * @param[in]       platform   Reference to the hal platform object.
+     * @param[in]       model      Reference to the initialised model.
+     * @return          true if inference succeeds, false otherwise.
+     **/
+    bool RunInference(hal_platform& platform, arm::app::Model& model);
+
+    /**
+     * @brief           Read input and return as an integer.
+     * @param[in]       platform   Reference to the hal platform object.
+     * @param[in]       model      Reference to the initialised model.
+     * @return          Integer value corresponding to the user input.
+     **/
+    int ReadUserInputAsInt(hal_platform& platform);
+
+#if VERIFY_TEST_OUTPUT
+    /**
+     * @brief       Helper function to dump a tensor to stdout
+     * @param[in]   tensor  tensor to be dumped
+     * @param[in]   lineBreakForNumElements     number of elements
+     *              after which line break will be added.
+     **/
+    void DumpTensor(TfLiteTensor* tensor,
+                    const size_t lineBreakForNumElements = 16);
+#endif /* VERIFY_TEST_OUTPUT */
+
+    /**
+     * @brief       List the files baked in the application.
+     * @param[in]   ctx   Reference to the application context.
+     * @return      true or false based on event being handled.
+     **/
+    bool ListFilesHandler(ApplicationContext& ctx);
+
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* USECASE_COMMON_UTILS_HPP */
\ No newline at end of file