MLECO-1252 ASR sample application using the public ArmNN C++ API.
Change-Id: I98cd505b8772a8c8fa88308121bc94135bb45068
Signed-off-by: Éanna Ó Catháin <eanna.ocathain@arm.com>
diff --git a/samples/SpeechRecognition/include/SlidingWindow.hpp b/samples/SpeechRecognition/include/SlidingWindow.hpp
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+//
+// Copyright © 2020 Arm Ltd and Contributors. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#pragma once
+
+template<class T>
+class SlidingWindow
+{
+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;
+public:
+
+ /**
+ * Creates the window slider through the given data.
+ *
+ * @param data pointer to the data to slide through.
+ * @param dataSize size in T type elements wise.
+ * @param windowSize sliding window size in T type wise elements.
+ * @param 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;
+
+ /**
+ * 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;
+ }
+ }
+
+ /**
+ * 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);
+ }
+
+ /**
+ * Resest the slider to the initial position.
+ */
+ virtual void Reset()
+ {
+ m_count = 0;
+ }
+
+ /**
+ * Resest the slider to the initial position.
+ */
+ virtual size_t GetWindowSize()
+ {
+ return m_size;
+ }
+
+ /**
+ * Resets the slider to the start of the new data.
+ * New data size MUST be the same as the old one.
+ * @param newStart pointer to the new data to slide through.
+ */
+ virtual void Reset(T* newStart)
+ {
+ m_start = newStart;
+ Reset();
+ }
+
+ /**
+ * 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;
+ }
+
+ /**
+ * 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 size_t NextWindowStartIndex()
+ {
+ return m_count == 0? 0: ((m_count) * m_stride);
+ }
+
+ /**
+ * Go to given sliding window index.
+ * @param 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;
+ }
+
+ /**
+ * Calculates whole number of times the window can stride through the given data.
+ * @return maximum number of strides.
+ */
+ size_t TotalStrides()
+ {
+ if (m_size > m_dataSize)
+ {
+ return 0;
+ }
+ return ((m_dataSize - m_size)/m_stride);
+ }
+
+ /**
+ * 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_size > this->m_dataSize)
+ {
+ return this->m_dataSize / this->m_size;
+ }
+ else
+ {
+ return ((this->m_dataSize - this->m_size)/ static_cast<float>(this->m_stride));
+ }
+
+ }
+
+ /**
+ * Calculates the remaining data left to be processed
+ * @return The remaining unprocessed data
+ */
+ int RemainingData()
+ {
+ return this->m_dataSize - this->NextWindowStartIndex();
+ }
+};
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