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diff --git a/source/use_case/kws_asr/include/Wav2LetterPreprocess.hpp b/source/use_case/kws_asr/include/Wav2LetterPreprocess.hpp
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-/*
- * Copyright (c) 2021-2022 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_WAV2LETTER_PREPROCESS_HPP
-#define KWS_ASR_WAV2LETTER_PREPROCESS_HPP
-
-#include "Wav2LetterModel.hpp"
-#include "Wav2LetterMfcc.hpp"
-#include "AudioUtils.hpp"
-#include "DataStructures.hpp"
-#include "BaseProcessing.hpp"
-#include "log_macros.h"
-
-namespace arm {
-namespace app {
-
- /* Class to facilitate pre-processing calculation for Wav2Letter model
- * for ASR. */
- using AudioWindow = audio::SlidingWindow<const int16_t>;
-
- class AsrPreProcess : public BasePreProcess {
- public:
- /**
- * @brief Constructor.
- * @param[in] inputTensor Pointer to the TFLite Micro input Tensor.
- * @param[in] numMfccFeatures Number of MFCC features per window.
- * @param[in] numFeatureFrames Number of MFCC vectors that need to be calculated
- * for an inference.
- * @param[in] mfccWindowLen Number of audio elements to calculate MFCC features per window.
- * @param[in] mfccWindowStride Stride (in number of elements) for moving the MFCC window.
- */
- AsrPreProcess(TfLiteTensor* inputTensor,
- uint32_t numMfccFeatures,
- uint32_t numFeatureFrames,
- uint32_t mfccWindowLen,
- uint32_t mfccWindowStride);
-
- /**
- * @brief Calculates the features required from audio data. This
- * includes MFCC, first and second order deltas,
- * normalisation and finally, quantisation. The tensor is
- * populated with features from a given window placed along
- * in a single row.
- * @param[in] audioData Pointer to the first element of audio data.
- * @param[in] audioDataLen Number of elements in the audio data.
- * @return true if successful, false in case of error.
- */
- bool DoPreProcess(const void* audioData, size_t audioDataLen) override;
-
- protected:
- /**
- * @brief Computes the first and second order deltas for the
- * MFCC buffers - they are assumed to be populated.
- *
- * @param[in] mfcc MFCC buffers.
- * @param[out] delta1 Result of the first diff computation.
- * @param[out] delta2 Result of the second diff computation.
- * @return true if successful, false otherwise.
- */
- static bool ComputeDeltas(Array2d<float>& mfcc,
- Array2d<float>& delta1,
- Array2d<float>& delta2);
-
- /**
- * @brief Given a 2D vector of floats, rescale it to have mean of 0 and
- * standard deviation of 1.
- * @param[in,out] vec Vector of vector of floats.
- */
- static void StandardizeVecF32(Array2d<float>& vec);
-
- /**
- * @brief Standardizes all the MFCC and delta buffers to have mean 0 and std. dev 1.
- */
- void Standarize();
-
- /**
- * @brief Given the quantisation and data type limits, computes
- * the quantised values of a floating point input data.
- * @param[in] elem Element to be quantised.
- * @param[in] quantScale Scale.
- * @param[in] quantOffset Offset.
- * @param[in] minVal Numerical limit - minimum.
- * @param[in] maxVal Numerical limit - maximum.
- * @return Floating point quantised value.
- */
- static float GetQuantElem(
- float elem,
- float quantScale,
- int quantOffset,
- float minVal,
- float maxVal);
-
- /**
- * @brief Quantises the MFCC and delta buffers, and places them
- * in the output buffer. While doing so, it transposes
- * the data. Reason: Buffers in this class are arranged
- * for "time" axis to be row major. Primary reason for
- * this being the convolution speed up (as we can use
- * contiguous memory). The output, however, requires the
- * time axis to be in column major arrangement.
- * @param[in] outputBuf Pointer to the output buffer.
- * @param[in] outputBufSz Output buffer's size.
- * @param[in] quantScale Quantisation scale.
- * @param[in] quantOffset Quantisation offset.
- */
- template <typename T>
- bool Quantise(
- T* outputBuf,
- const uint32_t outputBufSz,
- const float quantScale,
- const int quantOffset)
- {
- /* Check the output size will fit everything. */
- if (outputBufSz < (this->m_mfccBuf.size(0) * 3 * sizeof(T))) {
- printf_err("Tensor size too small for features\n");
- return false;
- }
-
- /* Populate. */
- T* outputBufMfcc = outputBuf;
- T* outputBufD1 = outputBuf + this->m_numMfccFeats;
- T* outputBufD2 = outputBufD1 + this->m_numMfccFeats;
- const uint32_t ptrIncr = this->m_numMfccFeats * 2; /* (3 vectors - 1 vector) */
-
- const float minVal = std::numeric_limits<T>::min();
- const float maxVal = std::numeric_limits<T>::max();
-
- /* Need to transpose while copying and concatenating the tensor. */
- for (uint32_t j = 0; j < this->m_numFeatureFrames; ++j) {
- for (uint32_t i = 0; i < this->m_numMfccFeats; ++i) {
- *outputBufMfcc++ = static_cast<T>(AsrPreProcess::GetQuantElem(
- this->m_mfccBuf(i, j), quantScale,
- quantOffset, minVal, maxVal));
- *outputBufD1++ = static_cast<T>(AsrPreProcess::GetQuantElem(
- this->m_delta1Buf(i, j), quantScale,
- quantOffset, minVal, maxVal));
- *outputBufD2++ = static_cast<T>(AsrPreProcess::GetQuantElem(
- this->m_delta2Buf(i, j), quantScale,
- quantOffset, minVal, maxVal));
- }
- outputBufMfcc += ptrIncr;
- outputBufD1 += ptrIncr;
- outputBufD2 += ptrIncr;
- }
-
- return true;
- }
-
- private:
- audio::Wav2LetterMFCC m_mfcc; /* MFCC instance. */
- TfLiteTensor* m_inputTensor; /* Model input tensor. */
-
- /* Actual buffers to be populated. */
- Array2d<float> m_mfccBuf; /* Contiguous buffer 1D: MFCC */
- Array2d<float> m_delta1Buf; /* Contiguous buffer 1D: Delta 1 */
- Array2d<float> m_delta2Buf; /* Contiguous buffer 1D: Delta 2 */
-
- uint32_t m_mfccWindowLen; /* Window length for MFCC. */
- uint32_t m_mfccWindowStride; /* Window stride len for MFCC. */
- uint32_t m_numMfccFeats; /* Number of MFCC features per window. */
- uint32_t m_numFeatureFrames; /* How many sets of m_numMfccFeats. */
- AudioWindow m_mfccSlidingWindow; /* Sliding window to calculate MFCCs. */
-
- };
-
-} /* namespace app */
-} /* namespace arm */
-
-#endif /* KWS_ASR_WAV2LETTER_PREPROCESS_HPP */ \ No newline at end of file
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