[vorbis] Downsampling

[John Morton]

On Tuesday 29 January 2002 03:13, Wayne Nyhlen wrote:

> As I understand it, when you downsample or upsample
> with sox, you still need to apply a low pass filter
> to the output to get rid of the artifacts.  I think
> the oggenc does this by default which is why you
> don't hear it in your ogg file.
>
> I have never seen a good example of what values to
> use with a low pass filter in sox.  Does anyone have
> any idea of common values to use for down/up sampling?

<p>The 'lowp' effect doesn't do the hard cutoff that you're looking for; instead 
you'll want to try the 'filter' effect. However, in this case the 'resample' 
effect handles the low pass filtering as well. Have a look at the man
page.

John

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