66 lines
1.8 KiB
C++
66 lines
1.8 KiB
C++
/*
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* Copyright (C) 2018 Arm Limited or its affiliates. All rights reserved.
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the License); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an AS IS BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef __KWS_MFCC_H__
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#define __KWS_MFCC_H__
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#include "riscv_math.h"
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#include "string.h"
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#define SAMP_FREQ 16000
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#define NUM_FBANK_BINS 40
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#define MEL_LOW_FREQ 20
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#define MEL_HIGH_FREQ 4000
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#define M_2PI 6.283185307179586476925286766559005
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#define M_PI 3.14159265358979323846
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class MFCC {
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private:
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int num_mfcc_features;
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int frame_len;
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int frame_len_padded;
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int mfcc_dec_bits;
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float *frame;
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float *buffer;
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float *mel_energies;
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float *window_func;
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int32_t *fbank_filter_first;
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int32_t *fbank_filter_last;
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float **mel_fbank;
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float *dct_matrix;
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riscv_rfft_fast_instance_f32 *rfft;
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float *create_dct_matrix(int32_t input_length, int32_t coefficient_count);
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float **create_mel_fbank();
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static inline float InverseMelScale(float mel_freq)
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{
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return 700.0f * (expf(mel_freq / 1127.0f) - 1.0f);
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}
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static inline float MelScale(float freq)
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{
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return 1127.0f * logf(1.0f + freq / 700.0f);
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}
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public:
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MFCC(int num_mfcc_features, int frame_len, int mfcc_dec_bits);
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~MFCC();
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void mfcc_compute(const int16_t *data, q7_t *mfcc_out);
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};
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#endif |