overlap add versus overlap save

Hello all,
         i have searched the internet for information about which of the
two overlap methods is better but couldnt find any info. i am implementing
Decimation In Time fft in matlab. 
the entire process is:
1. audio sampling using wavread
2. computing fft of SEGMENTS of input audio samples
3. Computing fft of filter
4. Multiplying the two above fft's and taking inverse fft to get the
output.
  
i need to implement either overlap add or save to segment the input and to
combine the the segments of the output.

Which is better for implementation in matlab and which is better in
general?
Are they same? where could i get some info on this?

Habib


		
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habiblkk wrote:
> Hello all,
>          i have searched the internet for information about which of the
> two overlap methods is better but couldnt find any info. i am implementing
> Decimation In Time fft in matlab. 
> the entire process is:
> 1. audio sampling using wavread
> 2. computing fft of SEGMENTS of input audio samples
> 3. Computing fft of filter
> 4. Multiplying the two above fft's and taking inverse fft to get the
> output.
>   
> i need to implement either overlap add or save to segment the input and to
> combine the the segments of the output.
> 
> Which is better for implementation in matlab and which is better in
> general?
> Are they same? where could i get some info on this?

What you describe may be faster than time-domain filtering, but it's a 
lot more complicated. Do you really need to use this indirect approach?

Jerry
--
... the worst possible design that just meets the specification - almost
a definition of practical engineering.                     .. Chris Bore
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