Opensource ML embedded evaluation kit
Change-Id: I12e807f19f5cacad7cef82572b6dd48252fd61fd
diff --git a/source/use_case/asr/include/Wav2LetterPostprocess.hpp b/source/use_case/asr/include/Wav2LetterPostprocess.hpp
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+/*
+ * 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 ASR_WAV2LETTER_POSTPROCESS_HPP
+#define ASR_WAV2LETTER_POSTPROCESS_HPP
+
+#include "TensorFlowLiteMicro.hpp" /* TensorFlow headers. */
+#include "hal.h" /* stdout facility. */
+
+namespace arm {
+namespace app {
+namespace audio {
+namespace asr {
+
+ /**
+ * @brief Helper class to manage tensor post-processing for "wav2letter"
+ * output.
+ */
+ class Postprocess {
+ public:
+ /**
+ * @brief Constructor
+ * @param[in] contextLen Left and right context length for
+ * output tensor.
+ * @param[in] innerLen This is the length of the section
+ * between left and right context.
+ **/
+ Postprocess(uint32_t contextLen,
+ uint32_t innerLen,
+ uint32_t blankTokenIdx);
+
+ Postprocess() = delete;
+ ~Postprocess() = default;
+
+ /**
+ * @brief Erases the required part of the tensor based
+ * on context lengths set up during initialisation.
+ * @param[in] tensor Pointer to the tensor.
+ * @param[in] axisIdx Index of the axis on which erase is
+ * performed.
+ * @param[in] lastIteration Flag to signal this is the
+ * last iteration in which case
+ * the right context is preserved.
+ * @return true if successful, false otherwise.
+ */
+ bool Invoke(TfLiteTensor* tensor,
+ uint32_t axisIdx,
+ bool lastIteration = false);
+
+ private:
+ uint32_t _m_contextLen; /* lengths of left and right contexts. */
+ uint32_t _m_innerLen; /* Length of inner context. */
+ uint32_t _m_totalLen; /* Total length of the required axis. */
+ uint32_t _m_countIterations; /* Current number of iterations. */
+ uint32_t _m_blankTokenIdx; /* Index of the labels blank token. */
+ /**
+ * @brief Checks if the tensor and axis index are valid
+ * inputs to the object - based on how it has been
+ * initialised.
+ * @return true if valid, false otherwise.
+ */
+ bool _IsInputValid(TfLiteTensor* tensor,
+ uint32_t axisIdx) const;
+
+ /**
+ * @brief Gets the tensor data element size in bytes based
+ * on the tensor type.
+ * @return Size in bytes, 0 if not supported.
+ */
+ uint32_t _GetTensorElementSize(TfLiteTensor* tensor);
+
+ /**
+ * @brief Erases sections from the data assuming row-wise
+ * arrangement along the context axis.
+ * @return true if successful, false otherwise.
+ */
+ bool _EraseSectionsRowWise(uint8_t* ptrData,
+ uint32_t strideSzBytes,
+ bool lastIteration);
+
+ /**
+ * @brief Erases sections from the data assuming col-wise
+ * arrangement along the context axis.
+ * @return true if successful, false otherwise.
+ */
+ bool _EraseSectionsColWise(uint8_t* ptrData,
+ uint32_t strideSzBytes,
+ bool lastIteration);
+ };
+
+} /* namespace asr */
+} /* namespace audio */
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* ASR_WAV2LETTER_POSTPROCESS_HPP */
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