MLECO-1252 ASR sample application using the public ArmNN C++ API.

Change-Id: I98cd505b8772a8c8fa88308121bc94135bb45068
Signed-off-by: Éanna Ó Catháin <eanna.ocathain@arm.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/samples/SpeechRecognition/include/Decoder.hpp b/samples/SpeechRecognition/include/Decoder.hpp
new file mode 100644
index 0000000000..69d97ccf64
--- /dev/null
+++ b/samples/SpeechRecognition/include/Decoder.hpp
@@ -0,0 +1,63 @@
+//
+// Copyright © 2020 Arm Ltd and Contributors. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include <string>
+#include <map>
+#include <vector>
+#include <algorithm>
+#include <cmath>
+
+# pragma once
+
+namespace asr
+{
+/**
+* @brief Class used to Decode the output of the ASR inference
+*
+*/
+    class Decoder
+    {
+    public:
+        std::map<int, std::string> m_labels;
+        /**
+        * @brief Default constructor
+        * @param[in] labels - map of labels to be used for decoding to text.
+        */
+        Decoder(std::map<int, std::string>& labels);
+
+        /**
+        * @brief Function to decode the output into a text string
+        * @param[in] output - the output vector to decode.
+        */
+        template<typename T>
+        std::string DecodeOutput(std::vector<T>& contextToProcess)
+        {
+            int rowLength = 29;
+
+            std::vector<char> unfilteredText;
+
+            for(int row = 0; row < contextToProcess.size()/rowLength; ++row)
+            {
+                std::vector<int16_t> rowVector;
+                for(int j = 0; j < rowLength; ++j)
+                {
+                    rowVector.emplace_back(static_cast<int16_t>(contextToProcess[row * rowLength + j]));
+                }
+
+                int max_index = std::distance(rowVector.begin(),std::max_element(rowVector.begin(), rowVector.end()));
+                unfilteredText.emplace_back(this->m_labels.at(max_index)[0]);
+            }
+
+            std::string filteredText = FilterCharacters(unfilteredText);
+            return filteredText;
+        }
+
+        /**
+        * @brief Function to filter out unwanted characters
+        * @param[in] unfiltered - the unfiltered output to be processed.
+        */
+        std::string FilterCharacters(std::vector<char>& unfiltered);
+    };
+} // namespace asr