MLECO-1868: Code static analyzer warnings fixes

Signed-off-by: alexander <alexander.efremov@arm.com>
Change-Id: Ie423e9cad3fabec6ab077ded7236813fe4933dea
diff --git a/source/use_case/asr/src/AsrClassifier.cc b/source/use_case/asr/src/AsrClassifier.cc
index 7377d30..df26a7f 100644
--- a/source/use_case/asr/src/AsrClassifier.cc
+++ b/source/use_case/asr/src/AsrClassifier.cc
@@ -21,13 +21,18 @@
 #include "Wav2LetterModel.hpp"
 
 template<typename T>
-bool arm::app::AsrClassifier::_GetTopResults(TfLiteTensor* tensor,
-                            std::vector<ClassificationResult>& vecResults,
-                            const std::vector <std::string>& labels, double scale, double zeroPoint)
+bool arm::app::AsrClassifier::GetTopResults(TfLiteTensor* tensor,
+                                            std::vector<ClassificationResult>& vecResults,
+                                            const std::vector <std::string>& labels, double scale, double zeroPoint)
 {
     const uint32_t nElems = tensor->dims->data[arm::app::Wav2LetterModel::ms_outputRowsIdx];
     const uint32_t nLetters = tensor->dims->data[arm::app::Wav2LetterModel::ms_outputColsIdx];
 
+    if (nLetters != labels.size()) {
+        printf("Output size doesn't match the labels' size\n");
+        return false;
+    }
+
     /* NOTE: tensor's size verification against labels should be
      *       checked by the calling/public function. */
     if (nLetters < 1) {
@@ -58,12 +63,12 @@
 
     return true;
 }
-template bool arm::app::AsrClassifier::_GetTopResults<uint8_t>(TfLiteTensor* tensor,
-                            std::vector<ClassificationResult>& vecResults,
-                            const std::vector <std::string>& labels, double scale, double zeroPoint);
-template bool arm::app::AsrClassifier::_GetTopResults<int8_t>(TfLiteTensor* tensor,
-                            std::vector<ClassificationResult>& vecResults,
-                            const std::vector <std::string>& labels, double scale, double zeroPoint);
+template bool arm::app::AsrClassifier::GetTopResults<uint8_t>(TfLiteTensor* tensor,
+                                                              std::vector<ClassificationResult>& vecResults,
+                                                              const std::vector <std::string>& labels, double scale, double zeroPoint);
+template bool arm::app::AsrClassifier::GetTopResults<int8_t>(TfLiteTensor* tensor,
+                                                             std::vector<ClassificationResult>& vecResults,
+                                                             const std::vector <std::string>& labels, double scale, double zeroPoint);
 
 bool arm::app::AsrClassifier::GetClassificationResults(
             TfLiteTensor* outputTensor,
@@ -104,16 +109,16 @@
 
         switch (outputTensor->type) {
             case kTfLiteUInt8:
-                resultState = this->_GetTopResults<uint8_t>(
-                                        outputTensor, vecResults,
-                                        labels, quantParams.scale,
-                                        quantParams.offset);
+                resultState = this->GetTopResults<uint8_t>(
+                        outputTensor, vecResults,
+                        labels, quantParams.scale,
+                        quantParams.offset);
                 break;
             case kTfLiteInt8:
-                resultState = this->_GetTopResults<int8_t>(
-                                        outputTensor, vecResults,
-                                        labels, quantParams.scale,
-                                        quantParams.offset);
+                resultState = this->GetTopResults<int8_t>(
+                        outputTensor, vecResults,
+                        labels, quantParams.scale,
+                        quantParams.offset);
                 break;
             default:
                 printf_err("Tensor type %s not supported by classifier\n",
diff --git a/source/use_case/asr/src/UseCaseHandler.cc b/source/use_case/asr/src/UseCaseHandler.cc
index 5d3157a..efaefc2 100644
--- a/source/use_case/asr/src/UseCaseHandler.cc
+++ b/source/use_case/asr/src/UseCaseHandler.cc
@@ -35,7 +35,7 @@
     * @brief           Helper function to increment current audio clip index.
     * @param[in,out]   ctx   Pointer to the application context object.
     **/
-    static void _IncrementAppCtxClipIdx(ApplicationContext& ctx);
+    static void IncrementAppCtxClipIdx(ApplicationContext& ctx);
 
     /**
      * @brief           Helper function to set the audio clip index.
@@ -43,7 +43,7 @@
      * @param[in]       idx   Value to be set.
      * @return          true if index is set, false otherwise.
      **/
-    static bool _SetAppCtxClipIdx(ApplicationContext& ctx, uint32_t idx);
+    static bool SetAppCtxClipIdx(ApplicationContext& ctx, uint32_t idx);
 
     /**
      * @brief           Presents inference results using the data presentation
@@ -54,7 +54,7 @@
      *                              otherwise, this can be passed in as 0.
      * @return          true if successful, false otherwise.
      **/
-    static bool _PresentInferenceResult(
+    static bool PresentInferenceResult(
                     hal_platform& platform,
                     const std::vector<arm::app::asr::AsrResult>& results);
 
@@ -71,7 +71,7 @@
 
         /* If the request has a valid size, set the audio index. */
         if (clipIndex < NUMBER_OF_FILES) {
-            if (!_SetAppCtxClipIdx(ctx, clipIndex)) {
+            if (!SetAppCtxClipIdx(ctx, clipIndex)) {
                 return false;
             }
         }
@@ -207,20 +207,20 @@
 
             ctx.Set<std::vector<arm::app::asr::AsrResult>>("results", results);
 
-            if (!_PresentInferenceResult(platform, results)) {
+            if (!PresentInferenceResult(platform, results)) {
                 return false;
             }
 
             profiler.PrintProfilingResult();
 
-            _IncrementAppCtxClipIdx(ctx);
+            IncrementAppCtxClipIdx(ctx);
 
         } while (runAll && ctx.Get<uint32_t>("clipIndex") != startClipIdx);
 
         return true;
     }
 
-    static void _IncrementAppCtxClipIdx(ApplicationContext& ctx)
+    static void IncrementAppCtxClipIdx(ApplicationContext& ctx)
     {
         auto curAudioIdx = ctx.Get<uint32_t>("clipIndex");
 
@@ -232,7 +232,7 @@
         ctx.Set<uint32_t>("clipIndex", curAudioIdx);
     }
 
-    static bool _SetAppCtxClipIdx(ApplicationContext& ctx, const uint32_t idx)
+    static bool SetAppCtxClipIdx(ApplicationContext& ctx, uint32_t idx)
     {
         if (idx >= NUMBER_OF_FILES) {
             printf_err("Invalid idx %u (expected less than %u)\n",
@@ -244,8 +244,8 @@
         return true;
     }
 
-    static bool _PresentInferenceResult(hal_platform& platform,
-                                        const std::vector<arm::app::asr::AsrResult>& results)
+    static bool PresentInferenceResult(hal_platform& platform,
+                                       const std::vector<arm::app::asr::AsrResult>& results)
     {
         constexpr uint32_t dataPsnTxtStartX1 = 20;
         constexpr uint32_t dataPsnTxtStartY1 = 60;
diff --git a/source/use_case/asr/src/Wav2LetterMfcc.cc b/source/use_case/asr/src/Wav2LetterMfcc.cc
index 92c91bc..0eb152a 100644
--- a/source/use_case/asr/src/Wav2LetterMfcc.cc
+++ b/source/use_case/asr/src/Wav2LetterMfcc.cc
@@ -27,8 +27,8 @@
     bool Wav2LetterMFCC::ApplyMelFilterBank(
             std::vector<float>&                 fftVec,
             std::vector<std::vector<float>>&    melFilterBank,
-            std::vector<int32_t>&               filterBankFilterFirst,
-            std::vector<int32_t>&               filterBankFilterLast,
+            std::vector<uint32_t>&               filterBankFilterFirst,
+            std::vector<uint32_t>&               filterBankFilterLast,
             std::vector<float>&                 melEnergies)
     {
         const size_t numBanks = melEnergies.size();
@@ -41,11 +41,14 @@
 
         for (size_t bin = 0; bin < numBanks; ++bin) {
             auto filterBankIter = melFilterBank[bin].begin();
-            float melEnergy = 1e-10;  /* Avoid log of zero at later stages, same value used in librosa. */
-            const int32_t firstIndex = filterBankFilterFirst[bin];
-            const int32_t lastIndex = filterBankFilterLast[bin];
+            auto end = melFilterBank[bin].end();
+            /* Avoid log of zero at later stages, same value used in librosa.
+             * The number was used during our default wav2letter model training. */
+            float melEnergy = 1e-10;
+            const uint32_t firstIndex = filterBankFilterFirst[bin];
+            const uint32_t lastIndex = std::min<uint32_t>(filterBankFilterLast[bin], fftVec.size() - 1);
 
-            for (int32_t i = firstIndex; i <= lastIndex; ++i) {
+            for (uint32_t i = firstIndex; i <= lastIndex && filterBankIter != end; ++i) {
                 melEnergy += (*filterBankIter++ * fftVec[i]);
             }
 
@@ -73,7 +76,7 @@
 
         /* Scale the log values and get the max. */
         for (auto iterM = melEnergies.begin(), iterL = vecLogEnergies.begin();
-                  iterM != melEnergies.end(); ++iterM, ++iterL) {
+                  iterM != melEnergies.end() && iterL != vecLogEnergies.end(); ++iterM, ++iterL) {
 
             *iterM = *iterL * multiplier;
 
@@ -86,8 +89,8 @@
         /* Clamp the mel energies. */
         constexpr float maxDb = 80.0;
         const float clampLevelLowdB = maxMelEnergy - maxDb;
-        for (auto iter = melEnergies.begin(); iter != melEnergies.end(); ++iter) {
-            *iter = std::max(*iter, clampLevelLowdB);
+        for (float& melEnergy : melEnergies) {
+            melEnergy = std::max(melEnergy, clampLevelLowdB);
         }
     }
 
diff --git a/source/use_case/asr/src/Wav2LetterPostprocess.cc b/source/use_case/asr/src/Wav2LetterPostprocess.cc
index 60ee51e..9157a6f 100644
--- a/source/use_case/asr/src/Wav2LetterPostprocess.cc
+++ b/source/use_case/asr/src/Wav2LetterPostprocess.cc
@@ -39,13 +39,13 @@
                             const bool      lastIteration)
     {
         /* Basic checks. */
-        if (!this->_IsInputValid(tensor, axisIdx)) {
+        if (!this->IsInputValid(tensor, axisIdx)) {
             return false;
         }
 
         /* Irrespective of tensor type, we use unsigned "byte" */
         uint8_t* ptrData = tflite::GetTensorData<uint8_t>(tensor);
-        const uint32_t elemSz = this->_GetTensorElementSize(tensor);
+        const uint32_t elemSz = this->GetTensorElementSize(tensor);
 
         /* Other sanity checks. */
         if (0 == elemSz) {
@@ -59,13 +59,15 @@
         /* Which axis do we need to process? */
         switch (axisIdx) {
             case arm::app::Wav2LetterModel::ms_outputRowsIdx:
-                return this->_EraseSectionsRowWise(ptrData,
-                        elemSz * tensor->dims->data[arm::app::Wav2LetterModel::ms_outputColsIdx],
-                        lastIteration);
+                return this->EraseSectionsRowWise(ptrData,
+                                                  elemSz *
+                                                  tensor->dims->data[arm::app::Wav2LetterModel::ms_outputColsIdx],
+                                                  lastIteration);
             case arm::app::Wav2LetterModel::ms_outputColsIdx:
-                return this->_EraseSectionsColWise(ptrData,
-                        elemSz * tensor->dims->data[arm::app::Wav2LetterModel::ms_outputRowsIdx],
-                        lastIteration);
+                return this->EraseSectionsColWise(ptrData,
+                                                  elemSz *
+                                                  tensor->dims->data[arm::app::Wav2LetterModel::ms_outputRowsIdx],
+                                                  lastIteration);
             default:
                 printf_err("Unsupported axis index: %u\n", axisIdx);
         }
@@ -73,8 +75,8 @@
         return false;
     }
 
-    bool Postprocess::_IsInputValid(TfLiteTensor*  tensor,
-                                    const uint32_t axisIdx) const
+    bool Postprocess::IsInputValid(TfLiteTensor*  tensor,
+                                   const uint32_t axisIdx) const
     {
         if (nullptr == tensor) {
             return false;
@@ -96,17 +98,15 @@
         return true;
     }
 
-    uint32_t Postprocess::_GetTensorElementSize(TfLiteTensor*  tensor)
+    uint32_t Postprocess::GetTensorElementSize(TfLiteTensor*  tensor)
     {
         switch(tensor->type) {
             case kTfLiteUInt8:
-                return 1;
             case kTfLiteInt8:
                 return 1;
             case kTfLiteInt16:
                 return 2;
             case kTfLiteInt32:
-                return 4;
             case kTfLiteFloat32:
                 return 4;
             default:
@@ -117,7 +117,7 @@
         return 0;
     }
 
-    bool Postprocess::_EraseSectionsRowWise(
+    bool Postprocess::EraseSectionsRowWise(
                         uint8_t*         ptrData,
                         const uint32_t   strideSzBytes,
                         const bool       lastIteration)
@@ -154,8 +154,8 @@
         return true;
     }
 
-    bool Postprocess::_EraseSectionsColWise(
-                        uint8_t*         ptrData,
+    bool Postprocess::EraseSectionsColWise(
+                        const uint8_t*         ptrData,
                         const uint32_t   strideSzBytes,
                         const bool       lastIteration)
     {
diff --git a/source/use_case/asr/src/Wav2LetterPreprocess.cc b/source/use_case/asr/src/Wav2LetterPreprocess.cc
index e46cca3..d65ea75 100644
--- a/source/use_case/asr/src/Wav2LetterPreprocess.cc
+++ b/source/use_case/asr/src/Wav2LetterPreprocess.cc
@@ -88,12 +88,12 @@
         }
 
         /* Compute first and second order deltas from MFCCs. */
-        this->_ComputeDeltas(this->_m_mfccBuf,
-                             this->_m_delta1Buf,
-                             this->_m_delta2Buf);
+        Preprocess::ComputeDeltas(this->_m_mfccBuf,
+                            this->_m_delta1Buf,
+                            this->_m_delta2Buf);
 
         /* Normalise. */
-        this->_Normalise();
+        this->Normalise();
 
         /* Quantise. */
         QuantParams quantParams = GetTensorQuantParams(tensor);
@@ -105,11 +105,11 @@
 
         switch(tensor->type) {
             case kTfLiteUInt8:
-                return this->_Quantise<uint8_t>(
+                return this->Quantise<uint8_t>(
                         tflite::GetTensorData<uint8_t>(tensor), tensor->bytes,
                         quantParams.scale, quantParams.offset);
             case kTfLiteInt8:
-                return this->_Quantise<int8_t>(
+                return this->Quantise<int8_t>(
                         tflite::GetTensorData<int8_t>(tensor), tensor->bytes,
                         quantParams.scale, quantParams.offset);
             default:
@@ -120,9 +120,9 @@
         return false;
     }
 
-    bool Preprocess::_ComputeDeltas(Array2d<float>& mfcc,
-                                    Array2d<float>& delta1,
-                                    Array2d<float>& delta2)
+    bool Preprocess::ComputeDeltas(Array2d<float>& mfcc,
+                                   Array2d<float>& delta1,
+                                   Array2d<float>& delta2)
     {
         const std::vector <float> delta1Coeffs =
             {6.66666667e-02,  5.00000000e-02,  3.33333333e-02,
@@ -175,20 +175,20 @@
         return true;
     }
 
-    float Preprocess::_GetMean(Array2d<float>& vec)
+    float Preprocess::GetMean(Array2d<float>& vec)
     {
         return math::MathUtils::MeanF32(vec.begin(), vec.totalSize());
     }
 
-    float Preprocess::_GetStdDev(Array2d<float>& vec, const float mean)
+    float Preprocess::GetStdDev(Array2d<float>& vec, const float mean)
     {
         return math::MathUtils::StdDevF32(vec.begin(), vec.totalSize(), mean);
     }
 
-    void Preprocess::_NormaliseVec(Array2d<float>& vec)
+    void Preprocess::NormaliseVec(Array2d<float>& vec)
     {
-        auto mean = Preprocess::_GetMean(vec);
-        auto stddev = Preprocess::_GetStdDev(vec, mean);
+        auto mean = Preprocess::GetMean(vec);
+        auto stddev = Preprocess::GetStdDev(vec, mean);
 
         debug("Mean: %f, Stddev: %f\n", mean, stddev);
         if (stddev == 0) {
@@ -204,14 +204,14 @@
         }
     }
 
-    void Preprocess::_Normalise()
+    void Preprocess::Normalise()
     {
-        Preprocess::_NormaliseVec(this->_m_mfccBuf);
-        Preprocess::_NormaliseVec(this->_m_delta1Buf);
-        Preprocess::_NormaliseVec(this->_m_delta2Buf);
+        Preprocess::NormaliseVec(this->_m_mfccBuf);
+        Preprocess::NormaliseVec(this->_m_delta1Buf);
+        Preprocess::NormaliseVec(this->_m_delta2Buf);
     }
 
-    float Preprocess::_GetQuantElem(
+    float Preprocess::GetQuantElem(
                 const float     elem,
                 const float     quantScale,
                 const int       quantOffset,