python_kaldi_features

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forked from <https://github.com/jameslyons/python_speech_features>_

check the readme therein for the usages

It has been modified to produce the same results as with the compute-mfcc-feats and compute-fbank-feats (check their default parameters first) commands in Kaldi.

The compute-mfcc-feats pipeline:

src/featbin/Compute-mfcc-feats.cc

Mfcc mfcc(mfcc_opts)  --> src/feat/Feature-mfcc.h

                             struct MfccOptions
                             
                             typedef OfflineFeatureTpl<MfccComputer> Mfcc --> src/feat/Feature-common.h
       
                             MfccComputer()  --> src/feat/Feature-mfcc.cc
                             
                                                     ComputeDctMatrix()  --> src/matrix/Matrix-functions.cc
                                                     
                                                     ComputeLifterCoeffs()  --> src/feat/Mel-computations.cc


for each utterance:
mfcc.ComputeFeatures()

src/feat/Feature-common-inl.h

   OfflineFeatureTpl<F>::ComputeFeatures()

    Compute()
    
        ExtractWindow()  --> src/feat/Feature-window.cc
                                 
                                 ProcessWindow()
                                     
                                     Dither, remove_dc_offset, log_energy_pre_window, Preemphasize, window
        

           computer_.Compute() --> src/feat/Feature-mfcc.cc

                                  MfccComputer::Compute()
                                  

                                        const MelBanks &mel_banks --> Mel-computations.cc

                                         srfft_                                                                                 ComputerPowerSpectrum()

                                      mel_banks.Compute()
                                      
                                      mel_energies_.ApplyLog()
                                      
                                      dct, cepstral_lifter