smcgarry@dg-rtp.dg.com (Steve McGarry) (08/21/90)
I'm in need of a few simple explanations regarding DSP and I'm looking for someone to ask. Is there anyone in this newsgroup who can help me? Is there some other group I should be posting this to? Specifically, I haven't done any DSP work before and don't have a Calculus background (so the books that I've been reading are a bit confusing - they seem to regard these as prerequisites. The project I'm working on is a spectrum analysis of a digitized input signal. Is there any source code available (with some explanations) for doing FFTs or Digital Filtering? Thanks - Steve.
lseltzer@phoenix.Princeton.EDU (Linda Ann Seltzer) (08/23/90)
In article <812@dg.dg.com> smcgarry@dg-rtp.dg.com (Steve McGarry) writes: > >The project I'm working on is a spectrum analysis of a digitized input >signal. Is there any >source code available (with some explanations) for doing FFTs or Digital >Filtering? There are spectrum analyzers available which are stand alone units independent of any computer. Usually they take an analog input. B&K manufactures one. you would have to find some institution that owns one. Also, depending on your needs making spectrograms from an analog signal may be sufficient, unless you really need to know the exact numerical values of the locations of the peaks and valleys. So there may be ways you can look at the spectrum of a signal without worrying about FFT software. As for software, probably the best tool for you is the ILS signal processing package from Signal Technology in Santa Barbara. There are also other signal processing packages and they all include graphics. The problem is interpreting the output you get from these packages, because I guarantee you that you will not always get clean, understandable output. If what you want to see is a few peaks, doing linear prediction and then using the coefficients for spectral estimation would show you the peaks without all the harmonics and other garbage. So the first question to ask is - what kind of signal do you have and what are you interested in finding out. You will probably need to consult someone in electrical engineering at your institution to obtain help in using whatever software package they have.
sandell@ils.nwu.edu (Greg Sandell) (08/23/90)
I tried to reply directly to this one but couldn't... > In article <812@dg.dg.com> smcgarry@dg-rtp.dg.com (Steve McGarry) writes: > > > >The project I'm working on is a spectrum analysis of a digitized input > >signal. Is there any > >source code available (with some explanations) for doing FFTs or Digital > >Filtering? > Get ahold of THE ELEMENTS OF COMPUTER MUSIC by F.R. Moore, Prentice-Hall, 1990. Tons of source code in C. However, I am warned that the book is rife with errors, and the publisher should be contacted for errata. **************************************************************** * Greg Sandell (sandell@ils.nwu.edu) Evanston, IL * * Institute for the Learning Sciences, Northwestern University * ****************************************************************
todd@ivucsb.sba.ca.us (Todd Day) (08/23/90)
I tried to email you, but couldn't get through. You might want to try hanging out in comp.dsp. There are several knowledgable people there who can help you with basic DSP questions. -- Todd Day | todd@ivucsb.sba.ca.us | ucsbcsl!ivucsb!todd "I believed what I was told, I thought it was a good life, I thought I was happy. Then I found something that changed it all..." --- Anonymous, 2112
alfordr@musicbox.EBay.Sun.COM (Ronald Alford) (08/24/90)
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| | MUSITRONICS | computer music
O O ron alford | found sound
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