Chromaprint

https://oxygene.sk/2011/01/how-does-chromaprint-work/ Fingerprinting audio files:

• Take fourier transform of a sample of a window of x miliseconds

  (the windows move with an overlap of 2/3)

• Bin the fourier transform according to 12 notes. Then apply some filters (16 filters) on the binned transform.
• Discretize the output after filtering and convert the collection of 16 discrete value to an 32 bit integer
• The sequence of integers is the chromaprint