Author Topic: audio Spectrum analyzer  (Read 4424 times)

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Offline hellsangel

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audio Spectrum analyzer
« on: January 10, 2008 »
hi again

I want to make a spectrum analyzer with the player sc68, but...how the hell that works ?!?
I found some examples but many of them use fmod. One use an internal wav player. All seems to use FFT. it's the fft routines by Don Cross on code project used in this example.
my problem is...what datas use? where to find the good wave output data for fft ?
 :o hard

see attached files

Offline hellsangel

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Re: audio Spectrum analyzer
« Reply #1 on: January 10, 2008 »
second file+mods
« Last Edit: January 10, 2008 by [Y] »

Offline stormbringer

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Re: audio Spectrum analyzer
« Reply #2 on: January 10, 2008 »
SC68 is an emulator for Atari's Yamaha sound chipset and Amiga's Paula sound chipset. It has no idea about how the music is encoded/works since it executes original Motorola 68000 code. The original MC68000 code dumps PCM data into the emulated chipset registers... you will need to know a bit about how the orginal chipset works in order to create your analyser. Some original replay routines provide that information, so you would need to hack the emulator a bit to recover this information...

The other solution is to do it à  la Winamp => render the PCM samples into the audio buffer and FFT the resulting audio buffer and then analyse the data...
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Offline hellsangel

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Re: audio Spectrum analyzer
« Reply #3 on: January 10, 2008 »
ok
I think the second way is better

the audio buffer and the render are in waveout.c, I think
ouch...I'll try...

Offline va!n

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Re: audio Spectrum analyzer
« Reply #4 on: January 11, 2008 »
hello [Y]
possible following link may be usefull for you... i am searching for fast FFT too but i will try out DFT first, maybe its good enough for spectrum analyse in realtime... i dont know yet

http://dbfinteractive.com/index.php?topic=2538.0
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Offline hellsangel

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Re: audio Spectrum analyzer
« Reply #5 on: January 11, 2008 »
thanks
many usefull links