| /* |
| * SPDX-FileCopyrightText: Copyright 2021-2022 Arm Limited and/or its affiliates <open-source-office@arm.com> |
| * 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 "BaseProcessing.hpp" |
| #include "Model.hpp" |
| #include "AsrClassifier.hpp" |
| #include "AsrResult.hpp" |
| #include "log_macros.h" |
| |
| namespace arm { |
| namespace app { |
| |
| /** |
| * @brief Helper class to manage tensor post-processing for "wav2letter" |
| * output. |
| */ |
| class AsrPostProcess : public BasePostProcess { |
| public: |
| bool m_lastIteration = false; /* Flag to set if processing the last set of data for a clip. */ |
| |
| /** |
| * @brief Constructor |
| * @param[in] outputTensor Pointer to the TFLite Micro output Tensor. |
| * @param[in] classifier Object used to get top N results from classification. |
| * @param[in] labels Vector of string labels to identify each output of the model. |
| * @param[in/out] result Vector of classification results to store decoded outputs. |
| * @param[in] outputContextLen Left/right context length for output tensor. |
| * @param[in] blankTokenIdx Index in the labels that the "Blank token" takes. |
| * @param[in] reductionAxis The axis that the logits of each time step is on. |
| **/ |
| AsrPostProcess(TfLiteTensor* outputTensor, AsrClassifier& classifier, |
| const std::vector<std::string>& labels, asr::ResultVec& result, |
| uint32_t outputContextLen, |
| uint32_t blankTokenIdx, uint32_t reductionAxis); |
| |
| /** |
| * @brief Should perform post-processing of the result of inference then |
| * populate ASR result data for any later use. |
| * @return true if successful, false otherwise. |
| **/ |
| bool DoPostProcess() override; |
| |
| /** @brief Gets the output inner length for post-processing. */ |
| static uint32_t GetOutputInnerLen(const TfLiteTensor*, uint32_t outputCtxLen); |
| |
| /** @brief Gets the output context length (left/right) for post-processing. */ |
| static uint32_t GetOutputContextLen(const Model& model, uint32_t inputCtxLen); |
| |
| /** @brief Gets the number of feature vectors to be computed. */ |
| static uint32_t GetNumFeatureVectors(const Model& model); |
| |
| private: |
| AsrClassifier& m_classifier; /* ASR Classifier object. */ |
| TfLiteTensor* m_outputTensor; /* Model output tensor. */ |
| const std::vector<std::string>& m_labels; /* ASR Labels. */ |
| asr::ResultVec & m_results; /* Results vector for a single inference. */ |
| uint32_t m_outputContextLen; /* lengths of left/right contexts for output. */ |
| uint32_t m_outputInnerLen; /* Length of output 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. */ |
| uint32_t m_reductionAxisIdx; /* Axis containing output logits for a single step. */ |
| |
| /** |
| * @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. |
| */ |
| static 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); |
| }; |
| |
| } /* namespace app */ |
| } /* namespace arm */ |
| |
| #endif /* ASR_WAV2LETTER_POSTPROCESS_HPP */ |