Muggy;182559 Wrote: > To go from 96kHz -> 44.1kHz the ideal approach is to first upsample by a > factor of 147 then downsample by a factor of 320. > > The upsampling involves simply adding zeros after each data point to > pad the data out - 146 zeros after every data point. This leaves the > frequency content unmolested over the bandwidth of the original > signal. > > An anti-aliasing low pass digital filter is then applied to remove all > the frequency content of the signal which can not be retained at the > new sampling rate. So for a final rate of 44.1kHz you'd choose a > cutoff frequency of 22.05kHz or lower. > > Then finally, you discard samples at the downsampling rate which in > this case would mean retaining 1 sample in each block of 320. > > I'm not sure whether this method is used where real-time resampling is > required due to the amount of data generated by the high upsampling > factor. Maybe most hardware will just interpolate the original signal > at the new data points?
I think that is what happens in real-time resampling - certainly I've read stuff in the past (which of course I can't find now) that explained why non integer multiple resampling was more "difficult"... -- Phil Leigh ------------------------------------------------------------------------ Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=32958 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
