(Not sure why I didn’t receive Rolf’s email directly…) Hi Rolf,
First, I should have pointed to this newer series of articles (of mine), not old ones, earlier in this thread. You’ll get a detailed explanation of why zeroes (and as Alex points out, the zeros can be handled efficiently so it’s a good thing anyway): http://www.earlevel.com/main/tag/sampling-theory-series/?order=ASC <http://www.earlevel.com/main/tag/sampling-theory-series/?order=ASC> Nigel > On Jul 24, 2018, at 7:53 AM, Tom O'Hara <[email protected]> wrote: > > Adding zeros is an advantage as then you don't need to calculate their > multiplication, as 0 x coefficient = 0 > > The filter order will be the same with zeros or repeated samples. > Tom > > On 7/24/2018 4:37 PM, [email protected] <mailto:[email protected]> > wrote: >> Hello Nigel >> >> could you please say a word more to what you mean by "2x", "3x"? >> >> Also I am again not sure why in this case, adding zeros is an advantage. I >> had expected to just copy the samples to have less work to do in filtering. >> I tested such things in MATLAB and found that feeding zeros needs more >> filter TAPs to come to the same result. >> >> Rolf >> >> >> Gesendet: Montag, 23. Juli 2018 um 18:25 Uhr >> Von: "Nigel Redmon" <[email protected]> <mailto:[email protected]> >> An: [email protected] <mailto:[email protected]> >> Betreff: Re: [music-dsp] resampling >> Some articles on my website: >> http://www.earlevel.com/main/category/digital-audio/sample-rate-conversion/ >> <http://www.earlevel.com/main/category/digital-audio/sample-rate-conversion/>, >> especially the 2010 articles, but the Amp Sim article might be a helpful >> overview. >> >> 48k -> 8k: Filter with a lowpass with cutoff below 4k; keep 1 sample, throw >> away 5, repeat. >> >> 8k -> 48k: Use 1 sample, follow it with 5 new samples of 0 value, repeat; >> filter with a lowpass filter with cutoff below 4k. >> >> >> >> <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> >> Virus-free. www.avg.com >> <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> >> <x-msg://18/#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> >> >> _______________________________________________ >> dupswapdrop: music-dsp mailing list >> [email protected] <mailto:[email protected]> >> https://lists.columbia.edu/mailman/listinfo/music-dsp >> <https://lists.columbia.edu/mailman/listinfo/music-dsp> > _______________________________________________ > dupswapdrop: music-dsp mailing list > [email protected] > https://lists.columbia.edu/mailman/listinfo/music-dsp
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