[PlanetCCRMA] Concerning Freqtweak

Sat Sep 25 21:31:29 PDT 2010

Hello fellow CCRMA users/developers.  I am beginning my introduction into DSP and I have found a program that I really want to learn how it works.  This program is Freqtweak!.  I am not as interested in the visual aspect although it is very neat as well.  

Here is my question to those who understand DSP more than I do:

Would it be beneficial to do a Fast Fourier Transform on a GPU instead of doing it on the CPU?  My guess is that modern CPUs are plenty fast for this type of thing.  From my calculations, the Front Side Bus of modern 64 bit CPU provides plenty of cycles for a FFT to take place.  However, the knobs can always be turned up, and I just wanted to 'experiment' with the idea.  Maybe the quality of sound reproduction could be improved by such a parallel approach.  

My worry is that this may further complicate the process since the the path of the signal(from a guitar) would then be  Input>Soundcard>CPU>GPU>CPU>Soundcard>Output.  As opposed to:
Input>Soundcard>CPU>Soundcard>Output.

I have not forgotten RAM, but the GPU uses it own RAM.  So i am just drawing a rough path.

Do you think that letting the GPU do some of the work  could possibly get a lower latency than is now possible, or is the bottleneck somehwhere else?  I am just thinking of ways to make the latency closer zero or, to imrpove the quality of these FFT effects that I use very often in my playing.

> From: planetccrma-request at ccrma.Stanford.EDU
> Subject: PlanetCCRMA Digest, Vol 31, Issue 27
> To: planetccrma at ccrma.Stanford.EDU
> Date: Sat, 25 Sep 2010 12:00:02 -0700
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> Today's Topics:
> 
>    1. Re: [LAD] a treasure trove of information on "Physical Audio
>       Signal Processing" (Renato)
>    2. trouble with iso files for FC13 (Tom Poe)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Fri, 24 Sep 2010 15:49:33 +0200
> From: Renato <rennabh at gmail.com>
> Subject: Re: [PlanetCCRMA] [LAD] a treasure trove of information on
> 	"Physical Audio Signal Processing"
> To: Niels Mayer <nielsmayer at gmail.com>
> Cc: PlanetCCRMA mailinglist <planetccrma at ccrma.Stanford.EDU>,	Linux
> 	Audio Developers <linux-audio-dev at lists.linuxaudio.org>
> Message-ID: <20100924154933.11952418 at gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> On Wed, 22 Sep 2010 18:45:03 -0700
> Niels Mayer <nielsmayer at gmail.com> wrote:
> 
> > Following a wikipedia link on karplus-strong synthesis posted
> > recently, I found this, which appears to be the online fount of all
> > knowledge for physical modelling and sound synthesis:
> > https://ccrma.stanford.edu/~jos/pasp/
> > (with links to examples, code, etc).
> > 
> > > PHYSICAL AUDIO SIGNAL PROCESSING
> > > FOR VIRTUAL MUSICAL INSTRUMENTS AND AUDIO EFFECTS
> > > JULIUS O. SMITH III
> > > Center for Computer Research in Music and Acoustics (CCRMA)
> > > Department of Music, Stanford University, Stanford, California
> > > 94305 USA
> > 
> > I figure someone will find this interesting. Plus it's cheaper than
> > buying the book:
> > 
> > ``Physical Audio Signal Processing'', by Julius O. Smith III, W3K
> > Publishing, 2010, ISBN 978-0-9745607-2-4.
> > Copyright ? 2010-09-08 by Julius O. Smith III
> > Center for Computer Research in Music and Acoustics (CCRMA),
> > Stanford University
> > 
> > Niels
> > http://nielsmayer.com
> > 
> > PS: Speaking of CCRMA. as seen recently in Linux Journal  (
> > http://www.linuxjournal.com/article/10725 ):
> > "Systems designed for power users tend to be both slick and decadent,
> > armed to the teeth with the kind of tools that would make most end
> > users crawl into a straitjacket and whine for their mommies. The
> > studio distributions, such as PlanetCCRMA and 64 Studio, tend to be
> > this variety."    (i think that's a geek's way of making a
> > compliment). _______________________________________________
> > Linux-audio-dev mailing list
> > Linux-audio-dev at lists.linuxaudio.org
> > http://lists.linuxaudio.org/listinfo/linux-audio-dev
> 
> wow, looks impressive. Does someone know how one would go about to make
> it a .ps or .pdf, for easier reading and printing? Or is it allready
> avaiable on the site and I missed it?
> 
> Also - I guess most of you know about this - here is another good
> online source for more generic DSP:
> http://www.dspguide.com/
> 
> 
> renato
> 
> 
> 
> ------------------------------
> 
> Message: 2
> Date: Fri, 24 Sep 2010 17:10:44 -0400
> From: Tom Poe <tompoe at meltel.net>
> Subject: [PlanetCCRMA] trouble with iso files for FC13
> To: planetccrma at ccrma.Stanford.EDU
> Message-ID: <201009241710.44502.tompoe at meltel.net>
> Content-Type: text/plain;  charset="us-ascii"
> 
> I have downloaded iso files from a couple of places on the Fedora site, and 
> keep getting hung at the screen that says it's copying image to disk.  I wait 
> about 15-20 minutes and it has only moved (within a half minute) to about the 
> 5% position on the tracker bar.  Should I wait longer?
> Tom
> 
> 
> 
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> End of PlanetCCRMA Digest, Vol 31, Issue 27
> *******************************************

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