Re: discuss [bug #43305] Hamming etc. windows are wrong

[Peter]

Please have a look at the firwin function in LTFAT. You need to fftshift the output to get the right sequence of numbers for a normal window. There you can find all the standard windows. 

We put a lot of effort into getting the numbers correct for firwin, because you cannot get perfect reconstruction in an MDCT (used for MP3 encoding) unless the symmetry and spacing is correct. 

Cheers, 
Peter

 (and sorry, my phone suck at bottom posting)

On 30. dec. 2014 21.56.12 CET, Doug Stewart <address@hidden> wrote:

On Tue, Dec 30, 2014 at 3:35 PM, Julien Bect <address@hidden> wrote:

Le 30/12/2014 19:58, Doug Stewart a écrit :

  I dont have Matlab so, would someone run
 hann(8) on matlab and see if the first number is non zero?

% Matlab R2012a

>> format long
>> hann(8)

ans =

                   0
   0.188255099070633
   0.611260466978157
   0.950484433951210
   0.950484433951210
   0.611260466978157
   0.188255099070633
                   0

--

Thanks Julien

 

So wikipedia is wrong in the graphs that show the 3 curves. 

I will put together some graphs and FFT pictures of what is happening.

Doug

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