[opus] High Sampling Rates

[Edwin van den Oetelaar]

On Sat, Jun 7, 2014 at 10:58 AM, Andrew Lentvorski <bsder at allcaps.org>
wrote:

>
>
> On 6/7/14, 1:55 AM, Jean-Marc Valin wrote:
> > Actually... no! 24-bit can indeed be useful as extra margin and Opus
> > can actually represent even more dynamic range than 24-bit PCM. That's
> > not the case for 192 kHz. There's no "margin" that 192 kHz buys you
> > over 48 kHz. You can do as much linear filtering as you like, the
> > stuff above 20 kHz isn't going to help you.
>
> But lots of effects are not linear--simulating a tube guitar amplifier,
> for example.
>
> Even something as straightforward as resampling a signal to 44.1KHz is
> going to benefit from starting at 192KHz rather than 48KHz.
>
> There may not be more signal information but there will be less noise.
>
>
Hello Andrew,
Do you have any references for me to investigate, I am trying to understand
how noise is reduced by introducing higher sampling rates. (I tried to
search, but maybe it is so obvious that nobody even explains it)

In resampling - as far as I understand it - you first limit the bandwidth
to the 1/2 the sampling rate to prevent aliasing problems.
If your input signal contains no energy outside the resampled bandwidth to
start with, how is this going to increase the signal to noise ratio?

Thanks for your time,

Edwin van den Oetelaar
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