Opensource ML embedded evaluation kit

Change-Id: I12e807f19f5cacad7cef82572b6dd48252fd61fd
diff --git a/source/use_case/asr/src/MainLoop.cc b/source/use_case/asr/src/MainLoop.cc
new file mode 100644
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+++ b/source/use_case/asr/src/MainLoop.cc
@@ -0,0 +1,230 @@
+/*
+ * 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 "hal.h"                     /* Brings in platform definitions. */
+#include "Labels.hpp"                /* For label strings. */
+#include "UseCaseHandler.hpp"        /* Handlers for different user options. */
+#include "Wav2LetterModel.hpp"       /* Model class for running inference. */
+#include "UseCaseCommonUtils.hpp"    /* Utils functions. */
+#include "AsrClassifier.hpp"         /* Classifier. */
+#include "InputFiles.hpp"            /* Generated audio clip header. */
+#include "Wav2LetterPreprocess.hpp"  /* Pre-processing class. */
+#include "Wav2LetterPostprocess.hpp" /* Post-processing class. */
+
+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: ");
+}
+
+/** @brief Verify input and output tensor are of certain min dimensions. */
+static bool VerifyTensorDimensions(const arm::app::Model& model);
+
+/** @brief Gets the number of MFCC features for a single window. */
+static uint32_t GetNumMfccFeatures(const arm::app::Model& model);
+
+/** @brief Gets the number of MFCC feature vectors to be computed. */
+static uint32_t GetNumMfccFeatureVectors(const arm::app::Model& model);
+
+/** @brief Gets the output context length (left and right) for post-processing. */
+static uint32_t GetOutputContextLen(const arm::app::Model& model,
+                                    uint32_t inputCtxLen);
+
+/** @brief Gets the output inner length for post-processing. */
+static uint32_t GetOutputInnerLen(const arm::app::Model& model,
+                                  uint32_t outputCtxLen);
+
+void main_loop(hal_platform& platform)
+{
+    arm::app::Wav2LetterModel model;  /* Model wrapper object. */
+
+    /* Load the model. */
+    if (!model.Init()) {
+        printf_err("Failed to initialise model\n");
+        return;
+    } else if (!VerifyTensorDimensions(model)) {
+        printf_err("Model's input or output dimension verification failed\n");
+        return;
+    }
+
+    /* Initialise pre-processing. */
+    arm::app::audio::asr::Preprocess prep(
+                                GetNumMfccFeatures(model),
+                                g_FrameLength,
+                                g_FrameStride,
+                                GetNumMfccFeatureVectors(model));
+
+    /* Initialise post-processing. */
+    const uint32_t outputCtxLen = GetOutputContextLen(model, g_ctxLen);
+    const uint32_t blankTokenIdx = 28;
+    arm::app::audio::asr::Postprocess postp(
+                                outputCtxLen,
+                                GetOutputInnerLen(model, outputCtxLen),
+                                blankTokenIdx);
+
+    /* Instantiate application context. */
+    arm::app::ApplicationContext caseContext;
+    std::vector <std::string> labels;
+    GetLabelsVector(labels);
+    arm::app::AsrClassifier classifier;  /* Classifier wrapper object. */
+
+    caseContext.Set<hal_platform&>("platform", platform);
+    caseContext.Set<arm::app::Model&>("model", model);
+    caseContext.Set<uint32_t>("clipIndex", 0);
+    caseContext.Set<uint32_t>("frameLength", g_FrameLength);
+    caseContext.Set<uint32_t>("frameStride", g_FrameStride);
+    caseContext.Set<float>("scoreThreshold", g_ScoreThreshold);  /* Score threshold. */
+    caseContext.Set<uint32_t>("ctxLen", g_ctxLen);  /* Left and right context length (MFCC feat vectors). */
+    caseContext.Set<const std::vector <std::string>&>("labels", labels);
+    caseContext.Set<arm::app::AsrClassifier&>("classifier", classifier);
+    caseContext.Set<arm::app::audio::asr::Preprocess&>("preprocess", prep);
+    caseContext.Set<arm::app::audio::asr::Postprocess&>("postprocess", postp);
+
+    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");
+}
+
+static bool VerifyTensorDimensions(const arm::app::Model& model)
+{
+    /* Populate tensor related parameters. */
+    TfLiteTensor* inputTensor = model.GetInputTensor(0);
+    if (!inputTensor->dims) {
+        printf_err("Invalid input tensor dims\n");
+        return false;
+    } else if (inputTensor->dims->size < 3) {
+        printf_err("Input tensor dimension should be >= 3\n");
+        return false;
+    }
+
+    TfLiteTensor* outputTensor = model.GetOutputTensor(0);
+    if (!outputTensor->dims) {
+        printf_err("Invalid output tensor dims\n");
+        return false;
+    } else if (outputTensor->dims->size < 3) {
+        printf_err("Output tensor dimension should be >= 3\n");
+        return false;
+    }
+
+    return true;
+}
+
+static uint32_t GetNumMfccFeatures(const arm::app::Model& model)
+{
+    TfLiteTensor* inputTensor = model.GetInputTensor(0);
+    const int inputCols = inputTensor->dims->data[arm::app::Wav2LetterModel::ms_inputColsIdx];
+    if (0 != inputCols % 3) {
+        printf_err("Number of input columns is not a multiple of 3\n");
+    }
+    return std::max(inputCols/3, 0);
+}
+
+static uint32_t GetNumMfccFeatureVectors(const arm::app::Model& model)
+{
+    TfLiteTensor* inputTensor = model.GetInputTensor(0);
+    const int inputRows = inputTensor->dims->data[arm::app::Wav2LetterModel::ms_inputRowsIdx];
+    return std::max(inputRows, 0);
+}
+
+static uint32_t GetOutputContextLen(const arm::app::Model& model, const uint32_t inputCtxLen)
+{
+    const uint32_t inputRows = GetNumMfccFeatureVectors(model);
+    const uint32_t inputInnerLen = inputRows - (2 * inputCtxLen);
+    constexpr uint32_t ms_outputRowsIdx = arm::app::Wav2LetterModel::ms_outputRowsIdx;
+
+    /* Check to make sure that the input tensor supports the above
+     * context and inner lengths. */
+    if (inputRows <= 2 * inputCtxLen || inputRows <= inputInnerLen) {
+        printf_err("Input rows not compatible with ctx of %u\n",
+            inputCtxLen);
+        return 0;
+    }
+
+    TfLiteTensor* outputTensor = model.GetOutputTensor(0);
+    const uint32_t outputRows = std::max(outputTensor->dims->data[ms_outputRowsIdx], 0);
+
+    const float tensorColRatio = static_cast<float>(inputRows)/
+                                     static_cast<float>(outputRows);
+
+    return std::round(static_cast<float>(inputCtxLen)/tensorColRatio);
+}
+
+static uint32_t GetOutputInnerLen(const arm::app::Model& model,
+                                  const uint32_t outputCtxLen)
+{
+    constexpr uint32_t ms_outputRowsIdx = arm::app::Wav2LetterModel::ms_outputRowsIdx;
+    TfLiteTensor* outputTensor = model.GetOutputTensor(0);
+    const uint32_t outputRows = std::max(outputTensor->dims->data[ms_outputRowsIdx], 0);
+    return (outputRows - (2 * outputCtxLen));
+}