(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 <tom_i...@ticino.com> 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, rolfsassin...@web.de <mailto:rolfsassin...@web.de> 
> 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" <earle...@earlevel.com> <mailto:earle...@earlevel.com>
>> An: music-dsp@music.columbia.edu <mailto:music-dsp@music.columbia.edu>
>> 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
>> music-dsp@music.columbia.edu <mailto:music-dsp@music.columbia.edu>
>> https://lists.columbia.edu/mailman/listinfo/music-dsp 
>> <https://lists.columbia.edu/mailman/listinfo/music-dsp>
> _______________________________________________
> dupswapdrop: music-dsp mailing list
> music-dsp@music.columbia.edu
> https://lists.columbia.edu/mailman/listinfo/music-dsp

_______________________________________________
dupswapdrop: music-dsp mailing list
music-dsp@music.columbia.edu
https://lists.columbia.edu/mailman/listinfo/music-dsp

Reply via email to