Section 5: DFT Applications, Spectrograms, and Examples

• Reading:
  • Chapter 8 (DFT Applications)

  • Windows (up through Blackman-Harris Window Family)

  • Short Time Fourier Transform (STF) (up through Classic Spectrograms)

  • Optional but you should know it: Appendix D (Sampling Theory)

  • Assignment 5

• Spectrogram Demos
  • Music Lab
  • Music Lab Spectrogram
  • https://borismus.github.io/spectrogram/

• Lecture Videos (Total Viewing Time $\approx$ 2 Hours):
  • Spectrum-Analyzing Frequencies in the ``Cracks'' between DFT Sinusoids [30:02]

  • FFT Examples in Matlab: DFT Sinusoid, Non-DFT Sinusoid, and Zero-Padded Windowed Sinusoid for Rectangular, Blackman, and Hann Windows, Spectral Interpolation, Main Lobe, Side Lobes, FFT of Complex Sinusoid [36:36]

  • Spectrograms, Matlab/Octave Implementation, Voice Spectrogram, Formants [11:24]

  • Plots of Blackman Window and its DFT Revisited [6:12]

  • Linear Time-Invariant (LTI) Filters, Convolution, Ideal Lowpass, Guard Band, Transition Band, Simplest Lowpass, Impulse Response, DTFT, Frequency Response, Linear Phase, Sinewave Analysis [38:36]

  • Application: Automatic Chord Recognition (ACE) [8:10]