Method MfccComputePreFeature

samples/common/src/Audio/MFCC.cpp:226–261

}

void MFCC::MfccComputePreFeature(const std::vector<float>& audioData)
{
    this->InitMelFilterBank();

    auto size = std::min(std::min(this->m_frame.size(), audioData.size()),
                         static_cast<size_t>(this->m_params.m_frameLen)) * sizeof(float);
    std::memcpy(this->m_frame.data(), audioData.data(), size);

    /* Apply window function to input frame. */
    for(size_t i = 0; i < this->m_params.m_frameLen; i++) 
    {
        this->m_frame[i] *= this->m_windowFunc[i];
    }

    /* Set remaining frame values to 0. */
    std::fill(this->m_frame.begin() + this->m_params.m_frameLen,this->m_frame.end(), 0);

    /* Compute FFT. */
    MathUtils::FftF32(this->m_frame, this->m_buffer);

    /* Convert to power spectrum. */
    this->ConvertToPowerSpectrum();

    /* Apply mel filterbanks. */
    if (!this->ApplyMelFilterBank(this->m_buffer,
                                  this->m_melFilterBank,
                                  this->m_filterBankFilterFirst,
                                  this->m_filterBankFilterLast,
                                  this->m_melEnergies)) 
    {
        printf("Failed to apply MEL filter banks\n");
    }

    /* Convert to logarithmic scale. */
    this->ConvertToLogarithmicScale(this->m_melEnergies);
}

std::vector<float> MFCC::MfccCompute(const std::vector<float>& audioData)
{