Tyler Nitsch

I just noticed that if I have a poly patch within a parent patch that downsamples by two, it's output is simply the downsampled values repeated.

Ie the sequence 1 2 3 4 5 becomes 1 1 3 3 5 5.

Is there a way to specify how the output of poly is upsampled to produce its output in the parent patch say to get something like 1 0 3 0 5 0 (ie zero padding). Or possible interpolating...

I seem to remember talking with somebody about this a while back but I can't seem to find any info in the forum.

I just noticed that if I have a poly patch within a parent patch that downsamples by two, it's output is simply the downsampled values repeated. 

Ie the sequence 1 2 3 4 5 becomes 1 1 3 3 5 5.  

Is there a way to specify how the output of poly is upsampled to produce its output in the parent patch say to get something like 1 0 3 0 5 0 (ie zero padding). Or possible interpolating... 

I seem to remember talking with somebody about this a while back but I can't seem to find any info in the forum.


poly-upsampling-methods

weird, i think poly~ has its own signal vector? check the documentation.

Ok I see what your saying. When you downsample by 2 within poly the signal vector size becomes half of that of the parent patch. I made a workaround by using a count~ to multiply the output of the poly~ so that every second sample is set to zero.

Ok I see what your saying. When you downsample by 2 within poly the signal vector size becomes half of that of the parent patch.  I made a workaround by using a count~ to multiply the output of the poly~ so that every second sample is set to zero.


Quote: Tyler Nitsch wrote on Sun, 08 April 2007 21:31

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> Ok I see what your saying. When you downsample by 2 within poly the signal vector size becomes half of that of the parent patch. I made a workaround by using a count~ to multiply the output of the poly~ so that every second sample is set to zero. 

you would have to interpolate it yourself - outside the poly

it was about 2 years ago here in the list where someone

gave an example, but i cant find it anymore. it was something

using count~ so that you know where you are ...

Quote: Tyler Nitsch wrote on Sun, 08 April 2007 21:31
----------------------------------------------------
> Ok I see what your saying. When you downsample by 2 within poly the signal vector size becomes half of that of the parent patch.  I made a workaround by using a count~ to multiply the output of the poly~ so that every second sample is set to zero.  
----------------------------------------------------

you would have to interpolate it yourself - outside the poly
patcher. 
it was about 2 years ago here in the list where someone
gave an example, but i cant find it anymore. it was something
using count~ so that you know where you are ...


> Ie the sequence 1 2 3 4 5 becomes 1 1 3 3 5 5.

which is what you would have to expect, you throw away information...

> Is there a way to specify how the output of poly is upsampled to

> porduce its output in the parent patch say to get something like 1 0

> 3 0 5 0 (ie zero padding). Or possible interpolating...

zero padding would screw your signal completely, why would you want that?...

Interpolating is just a low pass filter of half the samplerate (outside 

Tyler Nitsch schrieb:
> Ie the sequence 1 2 3 4 5 becomes 1 1 3 3 5 5.

> Is there a way to specify how the output of poly is upsampled to
> porduce its output in the parent patch say to get something like 1 0
> 3 0 5 0 (ie zero padding). Or possible interpolating...

zero padding would screw your signal completely, why would you want that?...
Interpolating is just a low pass filter of half the samplerate (outside 
of the poly~)...

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Stefan Tiedje------------x-------
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In a lot of DSP literature they all deal with upsampling thru zero insertion. I was trying to develope a multirate system that was based off of the perfect reconstruction filters. I used haar filters. The idea is to split a signals spectrum in half with the analysis filters... downsample each half and then upsample and filter using the resynthesis filters. Basically a one level realtime wavelet system. When you repeat sample values in the system I created it increases the overall power of the resultant signal which rendered the resythesis part of the patch inaccurate... after doing the zero insertion it worked. Unfortuneatly I cant' get more than one stage to work properly....

In a lot of DSP literature they all deal with upsampling thru zero insertion.  I was trying to develope a multirate system that was based off of the perfect reconstruction filters.  I used haar filters.  The idea is to split a signals spectrum in half with the analysis filters... downsample each half and then upsample and filter using the resynthesis filters.  Basically a one level realtime wavelet system. When you repeat sample values in the system I created it increases the overall power of the resultant signal which rendered the resythesis part of the patch inaccurate... after doing the zero insertion it worked.  Unfortuneatly I cant' get more than one stage to work properly....


poly~ upsampling methods