19: Phase Vocoder (part 2), C++ Real-Time Audio Programming with Bela

Lecture 19 of C++ Real-Time Audio Programming with Bela. This is the second of a three-part series on the phase vocoder, a powerful tool for manipulating audio in the frequency domain. This lectures introduces how to work with signals in the frequency domain.
In this lecture:
Section 1: The frequency domain 0:00
Section 2: FFT of a sine wave 8:40
Section 3: Estimating frequency from phase 16:08
Section 4: Choosing FFT and hop sizes 30:19
Section 5: Window functions 33:43
Example code and companion materials:
github.com/BelaPlatform/bela-...
This course is a deep dive into how Bela processes data, and how to implement real-time audio and interaction. If you want to learn or improve your skills with C++ and audio programming, this is a great way to start!
Bela is the open-source platform for creating beautiful interaction. If you’d like to get a Bela system to follow along with these lectures, visit shop.bela.io. Use promo code CREATEATHOME for £10 off Bela and Bela Mini Starter Kits.
Music by Vula Viel (vulaviel.com).

[@arsebiscuitsandwine]

These are fantastic, I'm so happy this course has continued so long.

[@rifosi]

Still learning a lot. Thanks!

[@jeyko666]

thx!!!

[@mr123leafman]

@28:00 I understand why binDeviation needs to be between -0.5 and 0.5 (so its the same bin) but I don't get how this formula provides this. The phase shift has been wrapped so it's between -pi and pi so by deviding this by 2*pi this already gives us the range of -0.5 to 0.5. Multiplying this by N/h is going to push this over the limits (as the FFT size is larger than the hop size so this term is larger than one). Where am I going wrong?!

[@dublan99]

I noticed the same thing. Were you able to figure out the right solution? For now I'm just doing `phaseDiff / (hopSize * TWO_PI)`, but I sometime end up with a frequency deviation of 20 from my oscillator sound cc @BelaPlatform 🙏

[@kostantinosmag2986]

This is Great.....

[@Catbangin]

Waiting for flanger effect 😁