1 files changed, 0 insertions, 141 deletions
diff --git a/source/use_case/kws_asr/src/Wav2LetterMfcc.cc b/source/use_case/kws_asr/src/Wav2LetterMfcc.cc
deleted file mode 100644
index f2c50f3..0000000
--- a/source/use_case/kws_asr/src/Wav2LetterMfcc.cc
+++ /dev/null
@@ -1,141 +0,0 @@
-/*
- * 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.
- */
-#include "Wav2LetterMfcc.hpp"
-
-#include "PlatformMath.hpp"
-#include "log_macros.h"
-
-#include <cfloat>
-
-namespace arm {
-namespace app {
-namespace audio {
-
-    bool Wav2LetterMFCC::ApplyMelFilterBank(
-            std::vector<float>&                 fftVec,
-            std::vector<std::vector<float>>&    melFilterBank,
-            std::vector<uint32_t>&              filterBankFilterFirst,
-            std::vector<uint32_t>&              filterBankFilterLast,
-            std::vector<float>&                 melEnergies)
-    {
-        const size_t numBanks = melEnergies.size();
-
-        if (numBanks != filterBankFilterFirst.size() ||
-                numBanks != filterBankFilterLast.size()) {
-            printf_err("unexpected filter bank lengths\n");
-            return false;
-        }
-
-        for (size_t bin = 0; bin < numBanks; ++bin) {
-            auto filterBankIter = melFilterBank[bin].begin();
-            auto end = melFilterBank[bin].end();
-            /* Avoid log of zero at later stages, same value used in librosa.
-             * The number was used during our default wav2letter model training. */
-            float melEnergy = 1e-10;
-            const uint32_t firstIndex = filterBankFilterFirst[bin];
-            const uint32_t lastIndex = std::min<uint32_t>(filterBankFilterLast[bin], fftVec.size() - 1);
-
-            for (uint32_t i = firstIndex; i <= lastIndex && filterBankIter != end; ++i) {
-                melEnergy += (*filterBankIter++ * fftVec[i]);
-            }
-
-            melEnergies[bin] = melEnergy;
-        }
-
-        return true;
-    }
-
-    void Wav2LetterMFCC::ConvertToLogarithmicScale(
-                            std::vector<float>& melEnergies)
-    {
-        float maxMelEnergy = -FLT_MAX;
-
-        /* Container for natural logarithms of mel energies. */
-        std::vector <float> vecLogEnergies(melEnergies.size(), 0.f);
-
-        /* Because we are taking natural logs, we need to multiply by log10(e).
-         * Also, for wav2letter model, we scale our log10 values by 10. */
-        constexpr float multiplier = 10.0 *  /* Default scalar. */
-                                      0.4342944819032518;  /* log10f(std::exp(1.0))*/
-
-        /* Take log of the whole vector. */
-        math::MathUtils::VecLogarithmF32(melEnergies, vecLogEnergies);
-
-        /* Scale the log values and get the max. */
-        for (auto iterM = melEnergies.begin(), iterL = vecLogEnergies.begin();
-                  iterM != melEnergies.end() && iterL != vecLogEnergies.end(); ++iterM, ++iterL) {
-
-            *iterM = *iterL * multiplier;
-
-            /* Save the max mel energy. */
-            if (*iterM > maxMelEnergy) {
-                maxMelEnergy = *iterM;
-            }
-        }
-
-        /* Clamp the mel energies. */
-        constexpr float maxDb = 80.0;
-        const float clampLevelLowdB = maxMelEnergy - maxDb;
-        for (float & melEnergie : melEnergies) {
-            melEnergie = std::max(melEnergie, clampLevelLowdB);
-        }
-    }
-
-    std::vector<float> Wav2LetterMFCC::CreateDCTMatrix(
-                                        const int32_t inputLength,
-                                        const int32_t coefficientCount)
-    {
-        std::vector<float> dctMatix(inputLength * coefficientCount);
-
-        /* Orthonormal normalization. */
-        const float normalizerK0 = 2 * math::MathUtils::SqrtF32(1.0f /
-                                        static_cast<float>(4*inputLength));
-        const float normalizer = 2 * math::MathUtils::SqrtF32(1.0f /
-                                        static_cast<float>(2*inputLength));
-
-        const float angleIncr = M_PI/inputLength;
-        float angle = angleIncr;  /* We start using it at k = 1 loop. */
-
-        /* First row of DCT will use normalizer K0 */
-        for (int32_t n = 0; n < inputLength; ++n) {
-            dctMatix[n] = normalizerK0  /* cos(0) = 1 */;
-        }
-
-        /* Second row (index = 1) onwards, we use standard normalizer. */
-        for (int32_t k = 1, m = inputLength; k < coefficientCount; ++k, m += inputLength) {
-            for (int32_t n = 0; n < inputLength; ++n) {
-                dctMatix[m+n] = normalizer *
-                    math::MathUtils::CosineF32((n + 0.5f) * angle);
-            }
-            angle += angleIncr;
-        }
-        return dctMatix;
-    }
-
-    float Wav2LetterMFCC::GetMelFilterBankNormaliser(
-                                    const float&    leftMel,
-                                    const float&    rightMel,
-                                    const bool      useHTKMethod)
-    {
-        /* Slaney normalization for mel weights. */
-        return (2.0f / (MFCC::InverseMelScale(rightMel, useHTKMethod) -
-                MFCC::InverseMelScale(leftMel, useHTKMethod)));
-    }
-
-} /* namespace audio */
-} /* namespace app */
-} /* namespace arm */