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  • 15. Re: How to create a Spectrum Analyzer?
    captfoss Pro
    Currently Being Moderated
    EJP wrote:
    Err, the topic is obviously analogue* signals. You don't need FFT for boolean logic signals.
    Right.

    By "line", I didn't mean something that carries a current, I meant a visual representation of a waveform... and (thus) by going up and down, I didn't mean "goes high" and "goes low", I meant that it cycles peroidically.

    :-)

    So I was being a @$$ hole rather than a dumb @$$...
  • 16. Re: How to create a Spectrum Analyzer?
    847432 Newbie
    Currently Being Moderated
    Hello,

    I still having difficulties to understand how to make this? How i pass the sound samples to frequencies? And than how i pass that frequencies to a line drawn in a JPanel?

    Sorry about this questions,

    But i really need help on this.

    I couldn't find nice things on google about creating audio spectrum analyzer wrote in java.
  • 17. Re: How to create a Spectrum Analyzer?
    EJP Guru
    Currently Being Moderated
    David, it is clear that you don't know the first thing about this. I suggest you hire someone who does. You're not going to solve this via a forum.
  • 18. Re: How to create a Spectrum Analyzer?
    847432 Newbie
    Currently Being Moderated
    But as someone that knows make this need to learned this in someway? So why i cant learned? That is not good man
  • 19. Re: How to create a Spectrum Analyzer?
    captfoss Pro
    Currently Being Moderated
    DavidHenriques wrote:
    But as someone that knows make this need to learned this in someway? So why i cant learned? That is not good man
    No one said you're incapable of learning how to do it, I'm sure you're perfectly capable of learning how to do it.

    But it's not possible to bring you up to speed in advanced topics like digital signal processing over a forum, when you're asking questions that are about on par with "How do I rebuild my engine" and "How come my airpane won't fly?"

    If you want to learn, go take a digital signal processing class at your local university. Otherwise, go find a spectrum analyzer library to ram into whatever you're trying to code. Whichever one makes your heart happier. You lack the fundaments and you're not going to have them spoon fed to you over a forum.
  • 20. Re: How to create a Spectrum Analyzer?
    sabre150 Expert
    Currently Being Moderated
    DavidHenriques wrote:
    But as someone that knows make this need to learned this in someway? So why i cant learned? That is not good man
    I did signal processing basics at university many many years ago. Later, my masters thesis was concerned with techniques for creating spectral estimates using the FFT and all the while I was researching this I was studying signal processing. Several years later I spent more than 15 year applying signal analysis to very complex systems and for all of these 15 years I was studying some aspect or other of signal processing. The point I am trying to make in this paragraph is that one needs to study signal analysis and this is best done by taking classes and then by reading books. A forum is most definitely not the place to learn about spectral estimation until one has a basic grounding in signal analysis and in particular in Fourier theory.

    A year or so ago I started trying to understand the Java sound API. I still don't understand it well but I do now understand how to process sound samples of various form (ulaw, alaw, big endian, little endian etc etc etc) so as to create sound values suitable for use in the processing for spectral estimation and other signal processing. As part of my studying the Java sound API I create a music player that plays OGG, MP3, AU and WAV files and displays both the sample values and the spectral values in real time. Much of the code is experimental and hueristic ; for example I did not know what collection period makes for a good display update rate and gives a reasonable frequency resolution and experimented until I found a reasonable value (0.2 second is a good compromise between frequency resolution and flicker). Since I found existing charting libraries did not perform well at the frame rates I was interested in, I had to write a simple high speed charting library. I already had my own mixed radix FFT libraries. The point I am trying to make with this paragraph is that I had to learn about the various programming aspects and I did that by reading tutorials, using Google, reading books and experimentation. Some of this can be learned by asking specific questions in this forum but only only only after one has spend some time learning enough to ask specific question.

    Read, experiment, ask questions of your tutor, ask specific question in a forum, read more, experiment more ......
  • 21. Re: How to create a Spectrum Analyzer?
    EJP Guru
    Currently Being Moderated
    DavidHenriques wrote:
    But as someone that knows make this need to learned this in someway? So why i cant learned? That is not good man
    David this is rubbish. You can't learn this from a forum. The topic is simply far too big. I said that.

    And keep the personal remarks to yourself.
  • 22. Re: How to create a Spectrum Analyzer?
    847432 Newbie
    Currently Being Moderated
    Ok i see, i understand now, this is not a thing that i learned in days... But i am not in the university so i can´t have class about this. As you said this take some years to learn how really works. But i don't have that time :/.

    So first step study DFT and FFT. I am reading this : http://www.dspguide.com/ch8/2.htm . Is about DSP.

    I am not so good programming but i need to make this, and i love sound area so i would like to acomplished this goal.
  • 23. Re: How to create a Spectrum Analyzer?
    847432 Newbie
    Currently Being Moderated
    Sorry EJP i didn't want to hurt your feelings, my bad. Don't take that personal.

    Cheers.
  • 24. Re: How to create a Spectrum Analyzer?
    captfoss Pro
    Currently Being Moderated
    DavidHenriques wrote:
    I am not so good programming but i need to make this, and i love sound area so i would like to acomplished this goal.
    I would point you at the following tutorial:
    http://jvalentino2.tripod.com/dft/index.html
  • 25. Re: How to create a Spectrum Analyzer?
    847432 Newbie
    Currently Being Moderated
    Thanks for the tip.
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