Re: [linux-audio-dev] Re: Looking for fast integer resampling code

From: Erik de Castro Lopo <erikd-lad@email-addr-hidden-nerd.com>
Date: Mon Jun 13 2005 - 23:46:03 EEST

Alfons Adriaensen wrote:

> On Mon, Jun 13, 2005 at 10:49:38PM +1000, Erik de Castro Lopo wrote:
>
> > The SNR and bandwith cannot be determined by reading code.
> > Measurement is the only option.
>
> It's perfectly possible to calculate this, and it isn't even
> very difficult. In the case of a sinc filter, everything is
> determined by the window on the complete sinc function that
> defines your filter, and the ratio of the two sample rates.
>
> In fact the 'measurement' you describe in the presentation
> you referred to is not really a measurement. It is 100%
> numerical and there's nothing physical involved. So it's in
> fact a long winded way to do the calculation.

Yes, but if you meaure the SNR the way I do, you are also
ensuring the absence of bugs in the implementation of the
algorithm. As you are probably aware, looking at code is
not the best way to find bugs in the implementation but
testing actually works quite well.

Erik

-- 
+-----------------------------------------------------------+
  Erik de Castro Lopo  nospam@email-addr-hidden-nerd.com (Yes it's valid)
+-----------------------------------------------------------+
"C++ is like jamming a helicopter inside a Miata and expecting 
some sort of improvement." -- Drew Olbrich
Received on Tue Jun 14 00:15:09 2005

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