I'm playing with Python & numpy to filter audio. It is relatively straightforward to design and us low-high-bandpass/stop FIR and IIR filters, stuff can be done in a couple of lines.
I'm implementing a small software defined radio software, and I need an all-pass filter that has 90 degrees phase shift everywhere, and is flat (as much as possible).
Unfortunately I was unable to find any quick solution for this.
Please share your thoughts on this.