FFT overlap-and-add

[Ingolf]

I have an FFT buffer which I do some processing on and then IFFT it. This won't work I knew because the start and endpoints will be hard-edged. Now I have multiplied the buffer size to overlap it etc, but I've tried a lot of things and I can't get it to work. It's:

buffer = 512
real size = 1024

512..1023 samples in -> do windowing -> FFT -> processing -> IFFT -> 512..1023 samples out -> move input and output samples 512..1023 to 0..511 for processing.

Now I had this, without the windowing, and it works off course, and with the windowing, I was able to overlap the buffers, but there were still clicks because of the hard-edges!!

I don't understand anymore... Can anyone help me pleaasse?

[Ingolf]

Anyone? sorry for my impatience...