Real-time spectrum analyzer with JACK

Programming applications for making music on Linux.

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d43156
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Real-time spectrum analyzer with JACK

Post by d43156 »

I would like to create a real-time spectrum analyzer from sound coming in from a microphone through JACK. I looked over the jaaa [ 1 ] source code [ 2 ] and read through some JACK documentation [ 3 ] and client examples [ 4 ], but I still do not understand how to separate the stream into the frequency bands and get the magnitude for each band.

Does anyone have recommended reading or an open-source library that has something like stream->get_magnitude(frequency) or stream->get_magnitude_of_range(lowest_frequency, highest_frequency)?

Thanks.

1 http://www.kokkinizita.net/linuxaudio/#jaaa
2 http://www.kokkinizita.net/linuxaudio/d ... index.html
3 http://jackaudio.org/documentation
4 http://dis-dot-dat.net/index.cgi?item=/ ... /starting/

brummer

Re: Real-time spectrum analyzer with JACK

Post by brummer »

Hi

Mostly you will use Fast Fourier Transforms to get information about frequency and time domain.
Here is a example prog for a spectrogram plot with fftw:
http://www.captain.at/howto-fftw-spectrograph.php

greats brummer

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autostatic
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Re: Real-time spectrum analyzer with JACK

Post by autostatic »

You could try ProjectM with a Spectrum Analyzer Milkdrop plugin: http://projectm.sourceforge.net/
Or maybe the JACK Oscrolloscope: http://das.nasophon.de/jack_oscrolloscope/

d43156
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Re: Real-time spectrum analyzer with JACK

Post by d43156 »

Thanks for the links. I am going to go with FFTW.

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autostatic
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Re: Real-time spectrum analyzer with JACK

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unfa
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Re: Real-time spectrum analyzer with JACK

Post by unfa »

Good to see you want to make such a program. I was thinking about it recently too, when I saw my friend using Foobar 2000. Stereo fullscreen spectrogram for JACK would be cool to analyse music, samples, voice, synth output...

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Re: Real-time spectrum analyzer with JACK

Post by unfa »

*bumps*

Is there any progress on this app? :)

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unfa
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Re: Real-time spectrum analyzer with JACK

Post by unfa »

I've found a program called Glfer:

http://www.qsl.net/in3otd/glfer.html

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