LPC Playback Formant-Shifting


So, I’ve been doing a bit of reading, and asked a questions on another forum, and it looks like this is more specifically what I need to do (according to Y(J)S’s reply on the dsprelated.com forum):

  1. Find the root of the LPC denominator polynomial
  2. Modify the pole angles and recompute the complex poles (with the original abs(?))
  3. Find the coefficients of the new denominator polynomial

I’m looking for root-finding algorithms in C at the moment. Maybe you have a recommendation for one fast enough to run in realtime on an M4?