Audio Signal Processing for Music Applications

[Gunther]

Marinus,

This is really a great book. Learned a lot from it and the explanations are very well done.

so it seems that it's worth the effort.  :t

Gunther

[Siekmanski]

Hi Gunther,
yes, it's not that difficult to read, and the explanations are very good also for beginners.

[Siekmanski]

Another free DSP book: https://archive.org/download/SignalProcessingFirst/SignalProcessingFirst-McclellanSchaferYoder.pdf

[Gunther]

Another free DSP book: https://archive.org/download/SignalProcessingFirst/SignalProcessingFirst-McclellanSchaferYoder.pdf

 :t

Gunther

[guga]

Ok, now i saw your fft analyser. Excllent work.

Will you release the source ? I would like to take a look at it how you managed to make the spectrum works.

Question. Can you make the spectrum be zoomed ? I mean, like we see in IzotopeRX or Audacity where the whole audio data is displayed and not just in runtime.

[Siekmanski]

Hi guga,

The routines for the FFT you can download here: see Reply #16
The analyzer is nothing more than a 1024 sample FFT normalized.

The magnitude spectrum is calculated as follows :
 do the FFT routine.
 Get the sqrt((Real*Real)+(Imag*Imag)) for every 512 positive complex sample. ( this is the first half of the FFT output)
 Then draw the result as lines to the screen.

To zoom the spectrum as i think you mean is choose an offset in your audiodata and do the FFT with the amount of samples you like 1024, 2048, 4096 etc.... and draw them to the screen.
Or get for example 200 audio samples and fill the rest with zeros to 2048 samples total and then do a FFT of 2048.
Now you have the frequency response of 200 samples zoomed out over 1024 output bins.