Hanning Window Object

toneburst · 2016-03-23 13:06:43 UTC

Could someone explain what the factory Window object is for?

a|x

thetechnobear · 2016-03-23 13:40:52 UTC

i suspect its a hanning window , google it with respect to something like pitch shifting, there should be some good examples of what it does.

johannes · 2016-03-23 13:48:03 UTC

A "window function" serves to cut out a limited time interval of a wave. Normally sound does not start or stop anywhere, and if you cut it straight where it is not silent, the cutting adds a little click sound. Such straight cut is called a "rectangular window". A "Hanning window" makes a nice smooth fade-in/fade-out volume ramp reducing the click sound. Many window functions exist: rectangular, triangular, Hanning, Blackman, Kaiser, each with specific properties... Often Hanning is an acceptable compromise.
Every textbook about DSP should contain an in-depth explanation. http://www.dspguide.com/ch9/1.htm

anon5189335 · 2016-03-23 14:32:09 UTC

Hanning windows can be used in many different contexts, like pitch shifting, time stretching & granular synthesis and is often also used in collaboration with fft. But in Axoloti we dont have fft....... yet ..... Hopefully one day

I think this explanation here gives a nice visual perspective of what is actually happening with the different window function:

http://zone.ni.com/reference/en-XX/help/371361H-01/lvanlsconcepts/char_smoothing_windows/

I would personally love som more window functions in Axoloti. When you only have one option and you know there are many others you always wonder what the others have to offer

I think I remember that I found some more window functions that was coded allready. Dunno if this code is useful for Axoloti. I found some other the other day, but cant find the link right now.

https://github.com/ddf/Minim/search?p=2&q=window&utf8=%E2%9C%93

EDIT:
Here are the ones I found the other day. They are from c-sound. Remembering reading in here somewhere that porting code from csound is not that difficult. So maybe something from thee could be used

github.com

csound/manual/blob/master/misc/windows.xml


<appendix id="MiscWindows">
  <title>Window Functions</title>

  <para>
    Windowing functions are used for analysis, and as waveform envelopes, particularly in granular synthesis. Window functions are built in to some opcodes, but others require a function table to generate the window. <link linkend="GEN20"><citetitle>GEN20</citetitle></link> is used for this purpose. The diagram of each window below, is accompanied by the f statement used to generate the it.
  </para>


  <formalpara>
    <title>Hamming</title>
    <para>
      <example>
        <title>Hamming window function statement</title>
        <programlisting><emphasis role="stamnt">f</emphasis>81   0   8192   20   1   1</programlisting>
      </example>

      <mediaobject>
        <imageobject>
          <imagedata fileref="images/image1.png" format="PNG"/>

This file has been truncated. show original

toneburst · 2016-03-23 16:34:14 UTC

Please excuse the terrible auto-correct-ism in the title
'Hanging window'....
So embarrassing...

a|x

toneburst · 2016-03-23 16:37:05 UTC

I think the function that actually creates the window isn't in that code- it's a list of parameters to be sent to a function somewhere else, that actually creates the window.

a|x

toneburst · 2016-03-23 16:38:06 UTC

Thanks guys.
Are there any Axoloti patches that show some of these possible applications?

a|x

anon5189335 · 2016-03-23 17:18:09 UTC

Hanging window... giggles

Yeah I opened the object and looked. There is not much to make out of it. I think line 19 is refering to some java code, that is not accesable through the object editor. For this I think you would need to have developer version of Axoloti and you would need to use X-Code to program it. Line 19 is the only line that doesnt look familiar in this object. And I think like in the nmpgen object you work on, that we changed the const to a dial in, the const and dial are reffering to different java documents. frac32 is one, int32 in another int32_radiov is another... And I think the:

   HANNING2TINTERP(inlet_phase<<5,r)

.... refers to java code.

johannes · 2016-03-23 17:38:35 UTC

You'd need developer skills.

That is incorrect, you're creating confusion here.

And really I don't believe you'd benefit so much from 20 different window functions.

anon5189335 · 2016-03-23 17:43:56 UTC

Cool. still learning. Thank you for the input

So it can be done on object level? No need to do edit java code?

kausto · 2016-03-23 17:52:06 UTC