sexta-feira, 9 de julho de 2010

Ok, a técnica

Há! Pensam que os "eletrônicos"* não gostam de futebol?
Pensam que só eu queria aniquilar o cara que inventou a vuvuzela?

Ok, eles não foram tão longe, mas tentaram amenizar o problema.

Diretamente do site da National Instruments:

World Cup 2010 - Filtering the Annoying Vuvuzela Noise

VERSION 1 
Created on: Jun 17, 2010 6:33 AM by Ferraro - Last Modified:  Jun 17, 2010 6:44 AM by Ferraro

Hey Guys- One of our LabVIEW product Managers, Simon Hogg put the following together.

The links didn't all copy over, but attched is the source code - fun stuff.  You can email Simon.Hogg@ni.com if you have any commnets or suggestions.

Hope all is well! Our next NOCLUG meeting is July 21st 2010.  See you then

Mr. Lawton, you'll enjoy the Mac files ;-)
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Now we're one week into the World Cup and two things have really annoyed me:

  1. England's lack of a reliable goalkeeper (I'm an Englishman living in Texas)
  2. The constant drone of the vuvuzelas (those noisy trumpets that sound like a million angry bees)

I'm a terrible goalkeeper and I wasn't named in the English squad so I can't help with #1 on my list but I am an engineer and I can do something about #2.

Other websites have covered various attempts at filtering the vuvuzela noise but none have offered much in the way of a solution you can use at home.  My solution is an application (written with LabVIEW) that detects the fundamental frequency of the vuvuzelas (around 233Hz) and applies a notch filter to it and as many harmonics as you specify.  The end result is a significant reduction in the annoying background noise without too much interruption of the commentary and other audio.
Vuvuzela Filter.png

Hardware-wise you will need to insert your computer in the audio signal flow.  If your TV has an audio output, connect that to your sound card's line in, then connect your sound card output to however you want to listen to the game (speakers or headphones).  I stream the game to an old PC I have in the corner of my cube and I have the audio output to my laptop, which applies the filter and then outputs to my headphones (don't tell my boss).

hw setup.png



Download an installer that includes both the EXE and the Run-Time Engine (for Windows).

NEW!  A Mac .dmg is also attached for those of you rocking Mac OSX.  You'll have to install the Mac Run-Time Engine if you don't already have it (I haven't had a chance to test this build but it should work).

You can download the source code and edit it with LabVIEW 2009 (get an evaluation copy here).  If you already have the free LabVIEW 2009 Run-Time Engine you can download just the attached zip file which contains the exe.
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* (The Thing Dictionary) "Eletrônicos": denonimação da era da 'eletrônica lascada' onde ainda existiam artesãos criativos na manipulação de elétrons e bytes.