| /* |
| * 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 KWS_ASR_WAV2LET_POSTPROC_HPP |
| #define KWS_ASR_WAV2LET_POSTPROC_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 is 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, |
| const 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, |
| const uint32_t strideSzBytes, |
| const bool lastIteration); |
| |
| }; |
| |
| } /* namespace asr */ |
| } /* namespace audio */ |
| } /* namespace app */ |
| } /* namespace arm */ |
| |
| #endif /* KWS_ASR_WAV2LET_POSTPROC_HPP */ |