Opensource ML embedded evaluation kit

Change-Id: I12e807f19f5cacad7cef82572b6dd48252fd61fd
diff --git a/source/use_case/kws/include/DsCnnMfcc.hpp b/source/use_case/kws/include/DsCnnMfcc.hpp
new file mode 100644
index 0000000..3f681af
--- /dev/null
+++ b/source/use_case/kws/include/DsCnnMfcc.hpp
@@ -0,0 +1,50 @@
+/*
+ * 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 KWS_DSCNN_MFCC_HPP
+#define KWS_DSCNN_MFCC_HPP
+
+#include "Mfcc.hpp"
+
+namespace arm {
+namespace app {
+namespace audio {
+
+    /* Class to provide DS-CNN specific MFCC calculation requirements. */
+    class DsCnnMFCC : public MFCC {
+
+    public:
+        static constexpr uint32_t  ms_defaultSamplingFreq = 16000;
+        static constexpr uint32_t  ms_defaultNumFbankBins =    40;
+        static constexpr uint32_t  ms_defaultMelLoFreq    =    20;
+        static constexpr uint32_t  ms_defaultMelHiFreq    =  4000;
+        static constexpr bool      ms_defaultUseHtkMethod =  true;
+
+        explicit DsCnnMFCC(const size_t numFeats, const size_t frameLen)
+            :  MFCC(MfccParams(
+                        ms_defaultSamplingFreq, ms_defaultNumFbankBins,
+                        ms_defaultMelLoFreq, ms_defaultMelHiFreq,
+                        numFeats, frameLen, ms_defaultUseHtkMethod))
+        {}
+        DsCnnMFCC()  = delete;
+        ~DsCnnMFCC() = default;
+    };
+
+} /* namespace audio */
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* KWS_DSCNN_MFCC_HPP */
\ No newline at end of file
diff --git a/source/use_case/kws/include/DsCnnModel.hpp b/source/use_case/kws/include/DsCnnModel.hpp
new file mode 100644
index 0000000..a4e7110
--- /dev/null
+++ b/source/use_case/kws/include/DsCnnModel.hpp
@@ -0,0 +1,59 @@
+/*
+ * 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 KWS_DSCNNMODEL_HPP
+#define KWS_DSCNNMODEL_HPP
+
+#include "Model.hpp"
+
+extern const int g_FrameLength;
+extern const int g_FrameStride;
+extern const float g_ScoreThreshold;
+
+namespace arm {
+namespace app {
+
+    class DsCnnModel : public Model {
+    public:
+        /* Indices for the expected model - based on input and output tensor shapes */
+        static constexpr uint32_t ms_inputRowsIdx = 2;
+        static constexpr uint32_t ms_inputColsIdx = 3;
+        static constexpr uint32_t ms_outputRowsIdx = 2;
+        static constexpr uint32_t ms_outputColsIdx = 3;
+    
+    protected:
+        /** @brief   Gets the reference to op resolver interface class. */
+        const tflite::MicroOpResolver& GetOpResolver() override;
+
+        /** @brief   Adds operations to the op resolver instance. */
+        bool EnlistOperations() override;
+
+        const uint8_t* ModelPointer() override;
+
+        size_t ModelSize() override;
+
+    private:
+        /* Maximum number of individual operations that can be enlisted. */
+        static constexpr int _ms_maxOpCnt = 8;
+
+        /* A mutable op resolver instance. */
+        tflite::MicroMutableOpResolver<_ms_maxOpCnt> _m_opResolver;
+    };
+
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* KWS_DSCNNMODEL_HPP */
diff --git a/source/use_case/kws/include/KwsResult.hpp b/source/use_case/kws/include/KwsResult.hpp
new file mode 100644
index 0000000..5a26ce1
--- /dev/null
+++ b/source/use_case/kws/include/KwsResult.hpp
@@ -0,0 +1,63 @@
+/*
+ * 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 KWS_RESULT_HPP
+#define KWS_RESULT_HPP
+
+#include "ClassificationResult.hpp"
+
+#include <vector>
+
+namespace arm {
+namespace app {
+namespace kws {
+
+    using ResultVec = std::vector < arm::app::ClassificationResult >;
+
+    /* Structure for holding kws result. */
+    class KwsResult {
+
+    public:
+        ResultVec       m_resultVec;        /* Container for "thresholded" classification results. */
+        float           m_timeStamp;        /* Audio timestamp for this result. */
+        uint32_t        m_inferenceNumber;  /* Corresponding inference number. */
+        float           m_threshold;        /* Threshold value for `m_resultVec`. */
+
+        KwsResult() = delete;
+        KwsResult(ResultVec&        resultVec,
+                  const float       timestamp,
+                  const uint32_t    inferenceIdx,
+                  const float       scoreThreshold) {
+
+            this->m_threshold = scoreThreshold;
+            this->m_timeStamp = timestamp;
+            this->m_inferenceNumber = inferenceIdx;
+
+            this->m_resultVec = ResultVec();
+            for (auto & i : resultVec) {
+                if (i.m_normalisedVal >= this->m_threshold) {
+                    this->m_resultVec.emplace_back(i);
+                }
+            }
+        }
+        ~KwsResult() = default;
+    };
+
+} /* namespace kws */
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* KWS_RESULT_HPP */
\ No newline at end of file
diff --git a/source/use_case/kws/include/UseCaseHandler.hpp b/source/use_case/kws/include/UseCaseHandler.hpp
new file mode 100644
index 0000000..1eb742f
--- /dev/null
+++ b/source/use_case/kws/include/UseCaseHandler.hpp
@@ -0,0 +1,37 @@
+/*
+ * 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 KWS_EVT_HANDLER_HPP
+#define KWS_EVT_HANDLER_HPP
+
+#include "AppContext.hpp"
+
+namespace arm {
+namespace app {
+
+    /**
+     * @brief       Handles the inference event.
+     * @param[in]   ctx         Pointer to the application context.
+     * @param[in]   clipIndex   Index to the audio clip to classify.
+     * @param[in]   runAll      Flag to request classification of all the available audio clips.
+     * @return      true or false based on execution success.
+     **/
+    bool ClassifyAudioHandler(ApplicationContext& ctx, uint32_t clipIndex, bool runAll);
+
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* KWS_EVT_HANDLER_HPP */
\ No newline at end of file
diff --git a/source/use_case/kws/src/DsCnnModel.cc b/source/use_case/kws/src/DsCnnModel.cc
new file mode 100644
index 0000000..a093eb4
--- /dev/null
+++ b/source/use_case/kws/src/DsCnnModel.cc
@@ -0,0 +1,58 @@
+/*
+ * 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 "DsCnnModel.hpp"
+
+#include "hal.h"
+
+const tflite::MicroOpResolver& arm::app::DsCnnModel::GetOpResolver()
+{
+    return this->_m_opResolver;
+}
+
+bool arm::app::DsCnnModel::EnlistOperations()
+{
+    this->_m_opResolver.AddReshape();
+    this->_m_opResolver.AddAveragePool2D();
+    this->_m_opResolver.AddConv2D();
+    this->_m_opResolver.AddDepthwiseConv2D();
+    this->_m_opResolver.AddFullyConnected();
+    this->_m_opResolver.AddRelu();
+    this->_m_opResolver.AddSoftmax();
+
+#if defined(ARM_NPU)
+    if (kTfLiteOk == this->_m_opResolver.AddEthosU()) {
+        info("Added %s support to op resolver\n",
+            tflite::GetString_ETHOSU());
+    } else {
+        printf_err("Failed to add Arm NPU support to op resolver.");
+        return false;
+    }
+#endif /* ARM_NPU */
+    return true;
+}
+
+extern uint8_t* GetModelPointer();
+const uint8_t* arm::app::DsCnnModel::ModelPointer()
+{
+    return GetModelPointer();
+}
+
+extern size_t GetModelLen();
+size_t arm::app::DsCnnModel::ModelSize()
+{
+    return GetModelLen();
+}
\ No newline at end of file
diff --git a/source/use_case/kws/src/MainLoop.cc b/source/use_case/kws/src/MainLoop.cc
new file mode 100644
index 0000000..24cb939
--- /dev/null
+++ b/source/use_case/kws/src/MainLoop.cc
@@ -0,0 +1,112 @@
+/*
+ * 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 "InputFiles.hpp"           /* For input audio clips. */
+#include "Classifier.hpp"           /* Classifier. */
+#include "DsCnnModel.hpp"           /* Model class for running inference. */
+#include "hal.h"                    /* Brings in platform definitions. */
+#include "Labels.hpp"               /* For label strings. */
+#include "UseCaseHandler.hpp"       /* Handlers for different user options. */
+#include "UseCaseCommonUtils.hpp"   /* Utils functions. */
+
+using KwsClassifier = arm::app::Classifier;
+
+enum opcodes
+{
+    MENU_OPT_RUN_INF_NEXT = 1,       /* Run on next vector. */
+    MENU_OPT_RUN_INF_CHOSEN,         /* Run on a user provided vector index. */
+    MENU_OPT_RUN_INF_ALL,            /* Run inference on all. */
+    MENU_OPT_SHOW_MODEL_INFO,        /* Show model info. */
+    MENU_OPT_LIST_AUDIO_CLIPS        /* List the current baked audio clips. */
+};
+
+static void DisplayMenu()
+{
+    printf("\n\nUser input required\n");
+    printf("Enter option number from:\n\n");
+    printf("  %u. Classify next audio clip\n", MENU_OPT_RUN_INF_NEXT);
+    printf("  %u. Classify audio clip at chosen index\n", MENU_OPT_RUN_INF_CHOSEN);
+    printf("  %u. Run classification on all audio clips\n", MENU_OPT_RUN_INF_ALL);
+    printf("  %u. Show NN model info\n", MENU_OPT_SHOW_MODEL_INFO);
+    printf("  %u. List audio clips\n\n", MENU_OPT_LIST_AUDIO_CLIPS);
+    printf("  Choice: ");
+}
+
+void main_loop(hal_platform& platform)
+{
+    arm::app::DsCnnModel model;  /* Model wrapper object. */
+
+    /* Load the model. */
+    if (!model.Init()) {
+        printf_err("Failed to initialise model\n");
+        return;
+    }
+
+    /* Instantiate application context. */
+    arm::app::ApplicationContext caseContext;
+
+    caseContext.Set<hal_platform&>("platform", platform);
+    caseContext.Set<arm::app::Model&>("model", model);
+    caseContext.Set<uint32_t>("clipIndex", 0);
+    caseContext.Set<int>("frameLength", g_FrameLength);
+    caseContext.Set<int>("frameStride", g_FrameStride);
+    caseContext.Set<float>("scoreThreshold", g_ScoreThreshold);  /* Normalised score threshold. */
+
+    KwsClassifier classifier;  /* classifier wrapper object. */
+    caseContext.Set<arm::app::Classifier&>("classifier", classifier);
+
+    std::vector <std::string> labels;
+    GetLabelsVector(labels);
+
+    caseContext.Set<const std::vector <std::string>&>("labels", labels);
+
+    bool executionSuccessful = true;
+    constexpr bool bUseMenu = NUMBER_OF_FILES > 1 ? true : false;
+
+    /* Loop. */
+    do {
+        int menuOption = MENU_OPT_RUN_INF_NEXT;
+        if (bUseMenu) {
+            DisplayMenu();
+            menuOption = arm::app::ReadUserInputAsInt(platform);
+            printf("\n");
+        }
+        switch (menuOption) {
+            case MENU_OPT_RUN_INF_NEXT:
+                executionSuccessful = ClassifyAudioHandler(caseContext, caseContext.Get<uint32_t>("clipIndex"), false);
+                break;
+            case MENU_OPT_RUN_INF_CHOSEN: {
+                printf("    Enter the audio clip index [0, %d]: ", NUMBER_OF_FILES-1);
+                auto clipIndex = static_cast<uint32_t>(arm::app::ReadUserInputAsInt(platform));
+                executionSuccessful = ClassifyAudioHandler(caseContext, clipIndex, false);
+                break;
+            }
+            case MENU_OPT_RUN_INF_ALL:
+                executionSuccessful = ClassifyAudioHandler(caseContext,caseContext.Get<uint32_t>("clipIndex"), true);
+                break;
+            case MENU_OPT_SHOW_MODEL_INFO:
+                executionSuccessful = model.ShowModelInfoHandler();
+                break;
+            case MENU_OPT_LIST_AUDIO_CLIPS:
+                executionSuccessful = ListFilesHandler(caseContext);
+                break;
+            default:
+                printf("Incorrect choice, try again.");
+                break;
+        }
+    } while (executionSuccessful && bUseMenu);
+    info("Main loop terminated.\n");
+}
\ No newline at end of file
diff --git a/source/use_case/kws/src/UseCaseHandler.cc b/source/use_case/kws/src/UseCaseHandler.cc
new file mode 100644
index 0000000..872d323
--- /dev/null
+++ b/source/use_case/kws/src/UseCaseHandler.cc
@@ -0,0 +1,452 @@
+/*
+ * 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 "UseCaseHandler.hpp"
+
+#include "InputFiles.hpp"
+#include "Classifier.hpp"
+#include "DsCnnModel.hpp"
+#include "hal.h"
+#include "DsCnnMfcc.hpp"
+#include "AudioUtils.hpp"
+#include "UseCaseCommonUtils.hpp"
+#include "KwsResult.hpp"
+
+#include <vector>
+#include <functional>
+
+using KwsClassifier = arm::app::Classifier;
+
+namespace arm {
+namespace app {
+
+    /**
+    * @brief            Helper function to increment current audio clip index.
+    * @param[in,out]    ctx   Pointer to the application context object.
+    **/
+    static void _IncrementAppCtxClipIdx(ApplicationContext& ctx);
+
+    /**
+     * @brief           Helper function to set the audio clip index.
+     * @param[in,out]   ctx   Pointer to the application context object.
+     * @param[in]       idx   Value to be set.
+     * @return          true if index is set, false otherwise.
+     **/
+    static bool _SetAppCtxClipIdx(ApplicationContext& ctx, uint32_t idx);
+
+    /**
+     * @brief           Presents inference results using the data presentation
+     *                  object.
+     * @param[in]       platform    Reference to the hal platform object.
+     * @param[in]       results     Vector of classification results to be displayed.
+     * @param[in]       infTimeMs   Inference time in milliseconds, if available,
+     *                              otherwise, this can be passed in as 0.
+     * @return          true if successful, false otherwise.
+     **/
+    static bool _PresentInferenceResult(hal_platform& platform,
+                                        const std::vector<arm::app::kws::KwsResult>& results);
+
+    /**
+     * @brief Returns a function to perform feature calculation and populates input tensor data with
+     * MFCC data.
+     *
+     * Input tensor data type check is performed to choose correct MFCC feature data type.
+     * If tensor has an integer data type then original features are quantised.
+     *
+     * Warning: MFCC calculator provided as input must have the same life scope as returned function.
+     *
+     * @param[in]       mfcc          MFCC feature calculator.
+     * @param[in,out]   inputTensor   Input tensor pointer to store calculated features.
+     * @param[in]       cacheSize     Size of the feature vectors cache (number of feature vectors).
+     * @return          Function to be called providing audio sample and sliding window index.
+     */
+    static std::function<void (std::vector<int16_t>&, int, bool, size_t)>
+            GetFeatureCalculator(audio::DsCnnMFCC&  mfcc,
+                                 TfLiteTensor*      inputTensor,
+                                 size_t             cacheSize);
+
+    /* Audio inference handler. */
+    bool ClassifyAudioHandler(ApplicationContext& ctx, uint32_t clipIndex, bool runAll)
+    {
+        auto& platform = ctx.Get<hal_platform&>("platform");
+
+        constexpr uint32_t dataPsnTxtInfStartX = 20;
+        constexpr uint32_t dataPsnTxtInfStartY = 40;
+        constexpr int minTensorDims = static_cast<int>(
+            (arm::app::DsCnnModel::ms_inputRowsIdx > arm::app::DsCnnModel::ms_inputColsIdx)?
+             arm::app::DsCnnModel::ms_inputRowsIdx : arm::app::DsCnnModel::ms_inputColsIdx);
+
+        platform.data_psn->clear(COLOR_BLACK);
+
+        auto& model = ctx.Get<Model&>("model");
+
+        /* If the request has a valid size, set the audio index. */
+        if (clipIndex < NUMBER_OF_FILES) {
+            if (!_SetAppCtxClipIdx(ctx, clipIndex)) {
+                return false;
+            }
+        }
+        if (!model.IsInited()) {
+            printf_err("Model is not initialised! Terminating processing.\n");
+            return false;
+        }
+
+        const auto frameLength = ctx.Get<int>("frameLength");
+        const auto frameStride = ctx.Get<int>("frameStride");
+        const auto scoreThreshold = ctx.Get<float>("scoreThreshold");
+        auto startClipIdx = ctx.Get<uint32_t>("clipIndex");
+
+        TfLiteTensor* outputTensor = model.GetOutputTensor(0);
+        TfLiteTensor* inputTensor = model.GetInputTensor(0);
+
+        if (!inputTensor->dims) {
+            printf_err("Invalid input tensor dims\n");
+            return false;
+        } else if (inputTensor->dims->size < minTensorDims) {
+            printf_err("Input tensor dimension should be >= %d\n", minTensorDims);
+            return false;
+        }
+
+        TfLiteIntArray* inputShape = model.GetInputShape(0);
+        const uint32_t kNumCols = inputShape->data[arm::app::DsCnnModel::ms_inputColsIdx];
+        const uint32_t kNumRows = inputShape->data[arm::app::DsCnnModel::ms_inputRowsIdx];
+
+        audio::DsCnnMFCC mfcc = audio::DsCnnMFCC(kNumCols, frameLength);
+        mfcc.Init();
+
+        /* Deduce the data length required for 1 inference from the network parameters. */
+        auto audioDataWindowSize = kNumRows * frameStride + (frameLength - frameStride);
+        auto mfccWindowSize = frameLength;
+        auto mfccWindowStride = frameStride;
+
+        /* We choose to move by half the window size => for a 1 second window size
+         * there is an overlap of 0.5 seconds. */
+        auto audioDataStride = audioDataWindowSize / 2;
+
+        /* To have the previously calculated features re-usable, stride must be multiple
+         * of MFCC features window stride. */
+        if (0 != audioDataStride % mfccWindowStride) {
+
+            /* Reduce the stride. */
+            audioDataStride -= audioDataStride % mfccWindowStride;
+        }
+
+        auto nMfccVectorsInAudioStride = audioDataStride/mfccWindowStride;
+
+        /* We expect to be sampling 1 second worth of data at a time.
+         * NOTE: This is only used for time stamp calculation. */
+        const float secondsPerSample = 1.0/audio::DsCnnMFCC::ms_defaultSamplingFreq;
+
+        do {
+            auto currentIndex = ctx.Get<uint32_t>("clipIndex");
+
+            /* Creating a mfcc features sliding window for the data required for 1 inference. */
+            auto audioMFCCWindowSlider = audio::SlidingWindow<const int16_t>(
+                                            get_audio_array(currentIndex),
+                                            audioDataWindowSize, mfccWindowSize,
+                                            mfccWindowStride);
+
+            /* Creating a sliding window through the whole audio clip. */
+            auto audioDataSlider = audio::SlidingWindow<const int16_t>(
+                                        get_audio_array(currentIndex),
+                                        get_audio_array_size(currentIndex),
+                                        audioDataWindowSize, audioDataStride);
+
+            /* Calculate number of the feature vectors in the window overlap region.
+             * These feature vectors will be reused.*/
+            auto numberOfReusedFeatureVectors = audioMFCCWindowSlider.TotalStrides() + 1
+                                                - nMfccVectorsInAudioStride;
+
+            /* Construct feature calculation function. */
+            auto mfccFeatureCalc = GetFeatureCalculator(mfcc, inputTensor,
+                                                        numberOfReusedFeatureVectors);
+
+            if (!mfccFeatureCalc){
+                return false;
+            }
+
+            /* Declare a container for results. */
+            std::vector<arm::app::kws::KwsResult> results;
+
+            /* Display message on the LCD - inference running. */
+            std::string str_inf{"Running inference... "};
+            platform.data_psn->present_data_text(
+                                str_inf.c_str(), str_inf.size(),
+                                dataPsnTxtInfStartX, dataPsnTxtInfStartY, 0);
+            info("Running inference on audio clip %u => %s\n", currentIndex,
+                 get_filename(currentIndex));
+
+            /* Start sliding through audio clip. */
+            while (audioDataSlider.HasNext()) {
+                const int16_t *inferenceWindow = audioDataSlider.Next();
+
+                /* We moved to the next window - set the features sliding to the new address. */
+                audioMFCCWindowSlider.Reset(inferenceWindow);
+
+                /* The first window does not have cache ready. */
+                bool useCache = audioDataSlider.Index() > 0 && numberOfReusedFeatureVectors > 0;
+
+                /* Start calculating features inside one audio sliding window. */
+                while (audioMFCCWindowSlider.HasNext()) {
+                    const int16_t *mfccWindow = audioMFCCWindowSlider.Next();
+                    std::vector<int16_t> mfccAudioData = std::vector<int16_t>(mfccWindow,
+                                                            mfccWindow + mfccWindowSize);
+                    /* Compute features for this window and write them to input tensor. */
+                    mfccFeatureCalc(mfccAudioData,
+                                    audioMFCCWindowSlider.Index(),
+                                    useCache,
+                                    nMfccVectorsInAudioStride);
+                }
+
+                info("Inference %zu/%zu\n", audioDataSlider.Index() + 1,
+                     audioDataSlider.TotalStrides() + 1);
+
+                /* Run inference over this audio clip sliding window. */
+                arm::app::RunInference(platform, model);
+
+                std::vector<ClassificationResult> classificationResult;
+                auto& classifier = ctx.Get<KwsClassifier&>("classifier");
+                classifier.GetClassificationResults(outputTensor, classificationResult,
+                                                    ctx.Get<std::vector<std::string>&>("labels"), 1);
+
+                results.emplace_back(kws::KwsResult(classificationResult,
+                    audioDataSlider.Index() * secondsPerSample * audioDataStride,
+                    audioDataSlider.Index(), scoreThreshold));
+
+#if VERIFY_TEST_OUTPUT
+                arm::app::DumpTensor(outputTensor);
+#endif /* VERIFY_TEST_OUTPUT */
+            } /* while (audioDataSlider.HasNext()) */
+
+            /* Erase. */
+            str_inf = std::string(str_inf.size(), ' ');
+            platform.data_psn->present_data_text(
+                                str_inf.c_str(), str_inf.size(),
+                                dataPsnTxtInfStartX, dataPsnTxtInfStartY, false);
+
+            ctx.Set<std::vector<arm::app::kws::KwsResult>>("results", results);
+
+            if (!_PresentInferenceResult(platform, results)) {
+                return false;
+            }
+
+            _IncrementAppCtxClipIdx(ctx);
+
+        } while (runAll && ctx.Get<uint32_t>("clipIndex") != startClipIdx);
+
+        return true;
+    }
+
+    static void _IncrementAppCtxClipIdx(ApplicationContext& ctx)
+    {
+        auto curAudioIdx = ctx.Get<uint32_t>("clipIndex");
+
+        if (curAudioIdx + 1 >= NUMBER_OF_FILES) {
+            ctx.Set<uint32_t>("clipIndex", 0);
+            return;
+        }
+        ++curAudioIdx;
+        ctx.Set<uint32_t>("clipIndex", curAudioIdx);
+    }
+
+    static bool _SetAppCtxClipIdx(ApplicationContext& ctx, const uint32_t idx)
+    {
+        if (idx >= NUMBER_OF_FILES) {
+            printf_err("Invalid idx %u (expected less than %u)\n",
+                       idx, NUMBER_OF_FILES);
+            return false;
+        }
+        ctx.Set<uint32_t>("clipIndex", idx);
+        return true;
+    }
+
+    static bool _PresentInferenceResult(hal_platform& platform,
+                                        const std::vector<arm::app::kws::KwsResult>& results)
+    {
+        constexpr uint32_t dataPsnTxtStartX1 = 20;
+        constexpr uint32_t dataPsnTxtStartY1 = 30;
+        constexpr uint32_t dataPsnTxtYIncr   = 16;  /* Row index increment. */
+
+        platform.data_psn->set_text_color(COLOR_GREEN);
+
+        /* Display each result */
+        uint32_t rowIdx1 = dataPsnTxtStartY1 + 2 * dataPsnTxtYIncr;
+
+        for (uint32_t i = 0; i < results.size(); ++i) {
+
+            std::string topKeyword{"<none>"};
+            float score = 0.f;
+
+            if (results[i].m_resultVec.size()) {
+                topKeyword = results[i].m_resultVec[0].m_label;
+                score = results[i].m_resultVec[0].m_normalisedVal;
+            }
+
+            std::string resultStr =
+                std::string{"@"} + std::to_string(results[i].m_timeStamp) +
+                std::string{"s: "} + topKeyword + std::string{" ("} +
+                std::to_string(static_cast<int>(score * 100)) + std::string{"%)"};
+
+            platform.data_psn->present_data_text(
+                                    resultStr.c_str(), resultStr.size(),
+                                    dataPsnTxtStartX1, rowIdx1, false);
+            rowIdx1 += dataPsnTxtYIncr;
+
+            info("For timestamp: %f (inference #: %u); threshold: %f\n",
+                    results[i].m_timeStamp, results[i].m_inferenceNumber,
+                    results[i].m_threshold);
+            for (uint32_t j = 0; j < results[i].m_resultVec.size(); ++j) {
+                info("\t\tlabel @ %u: %s, score: %f\n", j,
+                    results[i].m_resultVec[j].m_label.c_str(),
+                    results[i].m_resultVec[j].m_normalisedVal);
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * @brief Generic feature calculator factory.
+     *
+     * Returns lambda function to compute features using features cache.
+     * Real features math is done by a lambda function provided as a parameter.
+     * Features are written to input tensor memory.
+     *
+     * @tparam T            Feature vector type.
+     * @param inputTensor   Model input tensor pointer.
+     * @param cacheSize     Number of feature vectors to cache. Defined by the sliding window overlap.
+     * @param compute       Features calculator function.
+     * @return              Lambda function to compute features.
+     */
+    template<class T>
+    std::function<void (std::vector<int16_t>&, size_t, bool, size_t)>
+    _FeatureCalc(TfLiteTensor* inputTensor, size_t cacheSize,
+                 std::function<std::vector<T> (std::vector<int16_t>& )> compute)
+    {
+        /* Feature cache to be captured by lambda function. */
+        static std::vector<std::vector<T>> featureCache = std::vector<std::vector<T>>(cacheSize);
+
+        return [=](std::vector<int16_t>& audioDataWindow,
+                                     size_t index,
+                                     bool useCache,
+                                     size_t featuresOverlapIndex)
+        {
+            T *tensorData = tflite::GetTensorData<T>(inputTensor);
+            std::vector<T> features;
+
+            /* Reuse features from cache if cache is ready and sliding windows overlap.
+             * Overlap is in the beginning of sliding window with a size of a feature cache. */
+            if (useCache && index < featureCache.size()) {
+                features = std::move(featureCache[index]);
+            } else {
+                features = std::move(compute(audioDataWindow));
+            }
+            auto size = features.size();
+            auto sizeBytes = sizeof(T) * size;
+            std::memcpy(tensorData + (index * size), features.data(), sizeBytes);
+
+            /* Start renewing cache as soon iteration goes out of the windows overlap. */
+            if (index >= featuresOverlapIndex) {
+                featureCache[index - featuresOverlapIndex] = std::move(features);
+            }
+        };
+    }
+
+    template std::function<void (std::vector<int16_t>&, size_t , bool, size_t)>
+        _FeatureCalc<int8_t>(TfLiteTensor* inputTensor,
+                            size_t cacheSize,
+                            std::function<std::vector<int8_t> (std::vector<int16_t>& )> compute);
+
+    template std::function<void (std::vector<int16_t>&, size_t , bool, size_t)>
+        _FeatureCalc<uint8_t>(TfLiteTensor* inputTensor,
+                              size_t cacheSize,
+                              std::function<std::vector<uint8_t> (std::vector<int16_t>& )> compute);
+
+    template std::function<void (std::vector<int16_t>&, size_t , bool, size_t)>
+        _FeatureCalc<int16_t>(TfLiteTensor* inputTensor,
+                              size_t cacheSize,
+                              std::function<std::vector<int16_t> (std::vector<int16_t>& )> compute);
+
+    template std::function<void(std::vector<int16_t>&, size_t, bool, size_t)>
+        _FeatureCalc<float>(TfLiteTensor *inputTensor,
+                            size_t cacheSize,
+                            std::function<std::vector<float>(std::vector<int16_t>&)> compute);
+
+
+    static std::function<void (std::vector<int16_t>&, int, bool, size_t)>
+    GetFeatureCalculator(audio::DsCnnMFCC& mfcc, TfLiteTensor* inputTensor, size_t cacheSize)
+    {
+        std::function<void (std::vector<int16_t>&, size_t, bool, size_t)> mfccFeatureCalc;
+
+        TfLiteQuantization quant = inputTensor->quantization;
+
+        if (kTfLiteAffineQuantization == quant.type) {
+
+            auto *quantParams = (TfLiteAffineQuantization *) quant.params;
+            const float quantScale = quantParams->scale->data[0];
+            const int quantOffset = quantParams->zero_point->data[0];
+
+            switch (inputTensor->type) {
+                case kTfLiteInt8: {
+                    mfccFeatureCalc = _FeatureCalc<int8_t>(inputTensor,
+                                                           cacheSize,
+                                                           [=, &mfcc](std::vector<int16_t>& audioDataWindow) {
+                                                               return mfcc.MfccComputeQuant<int8_t>(audioDataWindow,
+                                                                                                    quantScale,
+                                                                                                    quantOffset);
+                                                           }
+                    );
+                    break;
+                }
+                case kTfLiteUInt8: {
+                    mfccFeatureCalc = _FeatureCalc<uint8_t>(inputTensor,
+                                                            cacheSize,
+                                                           [=, &mfcc](std::vector<int16_t>& audioDataWindow) {
+                                                               return mfcc.MfccComputeQuant<uint8_t>(audioDataWindow,
+                                                                                                     quantScale,
+                                                                                                     quantOffset);
+                                                           }
+                    );
+                    break;
+                }
+                case kTfLiteInt16: {
+                    mfccFeatureCalc = _FeatureCalc<int16_t>(inputTensor,
+                                                            cacheSize,
+                                                            [=, &mfcc](std::vector<int16_t>& audioDataWindow) {
+                                                                return mfcc.MfccComputeQuant<int16_t>(audioDataWindow,
+                                                                                                      quantScale,
+                                                                                                      quantOffset);
+                                                            }
+                    );
+                    break;
+                }
+                default:
+                    printf_err("Tensor type %s not supported\n", TfLiteTypeGetName(inputTensor->type));
+            }
+
+
+        } else {
+            mfccFeatureCalc = mfccFeatureCalc = _FeatureCalc<float>(inputTensor,
+                                                                    cacheSize,
+                                                                    [&mfcc](std::vector<int16_t>& audioDataWindow) {
+                                                                        return mfcc.MfccCompute(audioDataWindow);
+                                                                    });
+        }
+        return mfccFeatureCalc;
+    }
+
+} /* namespace app */
+} /* namespace arm */
\ No newline at end of file
diff --git a/source/use_case/kws/usecase.cmake b/source/use_case/kws/usecase.cmake
new file mode 100644
index 0000000..b5ac09e
--- /dev/null
+++ b/source/use_case/kws/usecase.cmake
@@ -0,0 +1,159 @@
+#----------------------------------------------------------------------------
+#  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.
+#----------------------------------------------------------------------------
+
+# If the path to a directory or source file has been defined,
+# get the type here (FILEPATH or PATH):
+if (DEFINED ${use_case}_FILE_PATH)
+    get_path_type(${${use_case}_FILE_PATH} PATH_TYPE)
+
+    # Set the default type if path is not a dir or file path (or undefined)
+    if (NOT ${PATH_TYPE} STREQUAL PATH AND NOT ${PATH_TYPE} STREQUAL FILEPATH)
+        message(FATAL_ERROR "Invalid ${use_case}_FILE_PATH. It should be a dir or file path.")
+    endif()
+else()
+    # Default is a directory path
+    set(PATH_TYPE PATH)
+endif()
+
+message(STATUS "${use_case}_FILE_PATH is of type: ${PATH_TYPE}")
+USER_OPTION(${use_case}_FILE_PATH "Directory with custom WAV input files, or path to a single WAV file, to use in the evaluation application."
+    ${CMAKE_CURRENT_SOURCE_DIR}/resources/${use_case}/samples/
+    ${PATH_TYPE})
+
+USER_OPTION(${use_case}_LABELS_TXT_FILE "Labels' txt file for the chosen model."
+    ${CMAKE_CURRENT_SOURCE_DIR}/resources/${use_case}/labels/ds_cnn_labels.txt
+    FILEPATH)
+
+USER_OPTION(${use_case}_AUDIO_RATE "Specify the target sampling rate. Default is 16000."
+    16000
+    STRING)
+
+USER_OPTION(${use_case}_AUDIO_MONO "Specify if the audio needs to be converted to mono. Default is ON."
+    ON
+    BOOL)
+
+USER_OPTION(${use_case}_AUDIO_OFFSET "Specify the offset to start reading after this time (in seconds). Default is 0."
+    0
+    STRING)
+
+USER_OPTION(${use_case}_AUDIO_DURATION "Specify the audio duration to load (in seconds). If set to 0 the entire audio will be processed."
+    0
+    STRING)
+
+USER_OPTION(${use_case}_AUDIO_RES_TYPE "Specify re-sampling algorithm to use. By default is 'kaiser_best'."
+    kaiser_best
+    STRING)
+
+USER_OPTION(${use_case}_AUDIO_MIN_SAMPLES "Specify the minimum number of samples to use. By default is 16000, if the audio is shorter will be automatically padded."
+    16000
+    STRING)
+
+USER_OPTION(${use_case}_MODEL_SCORE_THRESHOLD "Specify the score threshold [0.0, 1.0) that must be applied to the inference results for a label to be deemed valid."
+    0.9
+    STRING)
+
+# Generate input files
+generate_audio_code(${${use_case}_FILE_PATH} ${SRC_GEN_DIR} ${INC_GEN_DIR}
+    ${${use_case}_AUDIO_RATE}
+    ${${use_case}_AUDIO_MONO}
+    ${${use_case}_AUDIO_OFFSET}
+    ${${use_case}_AUDIO_DURATION}
+    ${${use_case}_AUDIO_RES_TYPE}
+    ${${use_case}_AUDIO_MIN_SAMPLES})
+
+# Generate labels file
+set(${use_case}_LABELS_CPP_FILE Labels)
+generate_labels_code(
+    INPUT           "${${use_case}_LABELS_TXT_FILE}"
+    DESTINATION_SRC ${SRC_GEN_DIR}
+    DESTINATION_HDR ${INC_GEN_DIR}
+    OUTPUT_FILENAME "${${use_case}_LABELS_CPP_FILE}"
+)
+
+USER_OPTION(${use_case}_ACTIVATION_BUF_SZ "Activation buffer size for the chosen model"
+    0x00100000
+    STRING)
+
+# If there is no tflite file pointed to
+if (NOT DEFINED ${use_case}_MODEL_TFLITE_PATH)
+
+    set(MODEL_FILENAME          ds_cnn_clustered_int8.tflite)
+    set(MODEL_RESOURCES_DIR     ${DOWNLOAD_DEP_DIR}/${use_case})
+    file(MAKE_DIRECTORY         ${MODEL_RESOURCES_DIR})
+    set(DEFAULT_MODEL_PATH      ${MODEL_RESOURCES_DIR}/${MODEL_FILENAME})
+
+    # Download the default model
+    set(ZOO_COMMON_SUBPATH      "models/keyword_spotting/ds_cnn_large/tflite_clustered_int8")
+    set(ZOO_MODEL_SUBPATH       "${ZOO_COMMON_SUBPATH}/${MODEL_FILENAME}")
+
+    download_file_from_modelzoo(${ZOO_MODEL_SUBPATH}    ${DEFAULT_MODEL_PATH})
+
+    if (ETHOS_U55_ENABLED)
+        message(STATUS
+            "Ethos-U55 is enabled, but the model downloaded is not optimized by vela. "
+            "To use Ethos-U55 acceleration, optimise the downloaded model and pass it "
+            "as ${use_case}_MODEL_TFLITE_PATH to the CMake configuration.")
+    endif()
+
+    # If the target platform is native
+    if (${TARGET_PLATFORM} STREQUAL native)
+
+        # Download test vectors
+        set(ZOO_TEST_IFM_SUBPATH    "${ZOO_COMMON_SUBPATH}/testing_input/input_2/0.npy")
+        set(ZOO_TEST_OFM_SUBPATH    "${ZOO_COMMON_SUBPATH}/testing_output/Identity/0.npy")
+
+        set(${use_case}_TEST_IFM    ${MODEL_RESOURCES_DIR}/ifm0.npy CACHE FILEPATH
+                                    "Input test vector for ${use_case}")
+        set(${use_case}_TEST_OFM    ${MODEL_RESOURCES_DIR}/ofm0.npy CACHE FILEPATH
+                                    "Input test vector for ${use_case}")
+
+        download_file_from_modelzoo(${ZOO_TEST_IFM_SUBPATH} ${${use_case}_TEST_IFM})
+        download_file_from_modelzoo(${ZOO_TEST_OFM_SUBPATH} ${${use_case}_TEST_OFM})
+
+        set(TEST_SRC_GEN_DIR ${CMAKE_BINARY_DIR}/generated/${use_case}/tests/src)
+        set(TEST_INC_GEN_DIR ${CMAKE_BINARY_DIR}/generated/${use_case}/tests/include)
+        file(MAKE_DIRECTORY ${TEST_SRC_GEN_DIR} ${TEST_INC_GEN_DIR})
+
+        # Generate test data files to be included in x86 tests
+        generate_test_data_code(
+                            INPUT_DIR "${DOWNLOAD_DEP_DIR}/${use_case}"
+                            DESTINATION_SRC ${TEST_SRC_GEN_DIR}
+                            DESTINATION_HDR ${TEST_INC_GEN_DIR}
+                            USECASE  "${use_case}")
+    endif()
+
+else()
+    set(DEFAULT_MODEL_PATH  "N/A")
+endif()
+
+set(EXTRA_MODEL_CODE
+    "/* Model parameters for ${use_case} */"
+    "extern const int   g_FrameLength    = 640"
+    "extern const int   g_FrameStride    = 320"
+    "extern const float g_ScoreThreshold = ${${use_case}_MODEL_SCORE_THRESHOLD}"
+    )
+
+USER_OPTION(${use_case}_MODEL_TFLITE_PATH "NN models file to be used in the evaluation application. Model files must be in tflite format."
+    ${DEFAULT_MODEL_PATH}
+    FILEPATH)
+
+# Generate model file
+generate_tflite_code(
+    MODEL_PATH ${${use_case}_MODEL_TFLITE_PATH}
+    DESTINATION ${SRC_GEN_DIR}
+    EXPRESSIONS ${EXTRA_MODEL_CODE}
+)