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Re: PC sound cards

Sampling rate conversion isn't just "correct" or "incorrect"; there's a
continuum of quality.  Perfect resampling requires infinitely long filters
with infinite wordlengths, so all real-world resamplers involve compromises
between quality and resources.  Some resampling algorithms do a better job
when the rate conversion ratio is a small-integer ratio, but other
algorithms work equally well for arbitrary ratios.

-- Dan Freed

-----Original Message-----
From: AUDITORY Research in Auditory Perception
[mailto:AUDITORY@LISTS.MCGILL.CA]On Behalf Of Pallier Christophe
Sent: Thursday, January 30, 2003 1:00 AM
Subject: Re: PC sound cards

On Thu, 30 Jan 2003, David Isherwood wrote:
> The main problem with such soundcards is that ALL internal processing
> is done at a sampling rate of 48kHz, which means that any audio stream
> having a different sampling rate than this must be upsampled at the i/p
> buss and downsampled at the o/p. The quality of this onboard sample rate
> conversion can vary greatly from card to card with some soundcards
> producing very noticeable artifacts.

Am I correct in believing that this implies that I should better
work with sampling rates that are integer dividers of 48 Khz (e.g. 16
Khz rather than, say, 22050 Hz)? I hope all sample rate
conversion algorithms should be able to correctly oversample by an
integer (?)

Christophe Pallier