How to center a window on a point?

Digital Signal Processing: What is the best algorithm for C based audio filtering (from microphone),I am filtering each 256 samples sequentially from alsa sound card using hamming 30 point hamming window multiplied by sinc in time domain(300-3400KHz)

• Pseudcode:-  256 samples 44100 sampling freq from Alsa sound card(using portaudio to create buffer and pass on to filter to make real time filtering) A=Time domain multiplication of 30 point hamming window and Sinc function(256 point 300-3200Khz). fft(256 point) of the "A" and signal. multiply freq domain signal and freq domain of product"A" ifft(256 point) save real of ifft in .wav file.

• Answer:

  Whats the sampling frequency? You need more details like cutoff frequency, sampling frequency and have to try out various filters which suits your need.