wehub-resource-sync
79 lines
2.6 KiB
C++
79 lines
2.6 KiB
C++
/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may 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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http://www.apache.org/licenses/LICENSE-2.0
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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,
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WITHOUT 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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// Basic class for computing MFCCs from spectrogram slices.
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#ifndef TENSORFLOW_LITE_KERNELS_INTERNAL_MFCC_H_
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#define TENSORFLOW_LITE_KERNELS_INTERNAL_MFCC_H_
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#include <vector>
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#include "tensorflow/lite/kernels/internal/mfcc_dct.h"
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#include "tensorflow/lite/kernels/internal/mfcc_mel_filterbank.h"
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namespace tflite {
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namespace internal {
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class Mfcc {
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public:
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Mfcc();
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bool Initialize(int input_length, double input_sample_rate);
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// Input is a single squared-magnitude spectrogram frame. The input spectrum
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// is converted to linear magnitude and weighted into bands using a
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// triangular mel filterbank, and a discrete cosine transform (DCT) of the
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// values is taken. Output is populated with the lowest dct_coefficient_count
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// of these values.
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void Compute(const std::vector<double>& spectrogram_frame,
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std::vector<double>* output) const;
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void set_upper_frequency_limit(double upper_frequency_limit) {
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// CHECK(!initialized_) << "Set frequency limits before calling
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// Initialize.";
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upper_frequency_limit_ = upper_frequency_limit;
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}
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void set_lower_frequency_limit(double lower_frequency_limit) {
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// CHECK(!initialized_) << "Set frequency limits before calling
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// Initialize.";
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lower_frequency_limit_ = lower_frequency_limit;
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}
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void set_filterbank_channel_count(int filterbank_channel_count) {
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/// CHECK(!initialized_) << "Set channel count before calling Initialize.";
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filterbank_channel_count_ = filterbank_channel_count;
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}
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void set_dct_coefficient_count(int dct_coefficient_count) {
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// CHECK(!initialized_) << "Set coefficient count before calling
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// Initialize.";
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dct_coefficient_count_ = dct_coefficient_count;
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}
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private:
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MfccMelFilterbank mel_filterbank_;
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MfccDct dct_;
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bool initialized_;
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double lower_frequency_limit_;
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double upper_frequency_limit_;
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int filterbank_channel_count_;
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int dct_coefficient_count_;
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};
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} // namespace internal
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} // namespace tflite
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#endif // TENSORFLOW_LITE_KERNELS_INTERNAL_MFCC_H_
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