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- Welcome to GFFT
- ------- -- ----
-
- This is the second public release of GFFT, an FFT-based
- spectrum analysis program with many features. Improvements
- include:
-
- -- an AmigaGuide discussion of Spectrum Analysis with
- many pictures!
-
- -- Support for different screens and (system default)
- fonts
-
- -- progress indicator with stop button
-
- -- support for GFFT commands in the icon tooltypes
-
- -- bugfixes and other small improvements
-
- If you would like to get the binary optimized for machines
- with FPU, please send $25. For best results, please specify the
- exact CPU and FPU (e.g. 25 MHz 68030 with 25 MHz 68882) you have.
-
- Address: Charles P. Peterson
- 4007 Enchanted Sun
- San Antonio, TX 78244-1254 USA
-
- E-mail: Charles_P_Peterson@fcircus.sat.tx.us
- cpp@crl.com
- charlesp@darwin.sfbr.org
-
- Please help me support this program by sending a donation of
- any amount. I will acknowledge all donations of $10 US or more
- with a short thank-you note and instructions as to how to disable
- the donation reminders. For a donation of $25 US, I will also send
- you a binary of the current release optimized for your system (with
- donation reminders disabled), AND advise you of the next release,
- which will be sent for the cost of shipping (which may be prepaid;
- allow for the weight of one floppy disk and packing materials).
- The ideas of contributors will be given extra weight in planning
- future releases.
-
- Even if you cannot afford to make a donation now, please
- let me know if you find the program useful, or how I might make
- it useful to you.
-
- Unique among programs available to the personal computer user,
- the design of GFFT emphasizes the ability to produce spectrum
- analyses of very high precision and accuracy. The tradeoff is
- speed; don't expect anything like real-time performance.* GFFT was
- never intended to be a real-time analyzer. My experience with most
- consumer real-time analyzers is that they are little better than
- toys, like a light show to watch while you are listening to music,
- and to really appreciate music, it's best not to watch such things
- anyway. By operating from stored sample data files, GFFT offers
- higher resolution and/or accuracy than most real-time analyzers.
- There is no limit to the length of samples that GFFT can analyze
- and average, and the longer the sample that is averaged, the more
- accurate the results can be. Without averaging over a significant
- period of time, a spectrum analysis is not much better than a list
- of random numbers.
-
- (*However, with suitably chosen parameters, GFFT can also give
- more approximate results in a few seconds. But why can't you wait
- a little longerfor something a little less random? See the
- SpectrumAnalysis.guide for a full discussion.)
-
- GFFT accepts 8, 12, or 16-bit data in in IFF 8SVX, AIFF, and
- AVR formats, or in unformatted files, and can accept data points
- entered through a console in floating point. GFFT can be operated
- from either a Workbench GUI or from a CLI in interactive or batch
- modes. It has built-in help facilities for all operating modes.
-
- Before running GFFT on your Amiga system, read the file named
- INSTALLATION. If you experience problems while running GFFT, see
- the file named Bugs. If you would like to read about how to use
- GFFT, you can read the file named GFFT.HELP, which is also used by
- GFFT to display help messages. After installing GFFT according to
- the instructions, you can get help while running GFFT either from
- the Workbench or from the CLI.
-
- If you want further information about the GNU General Public
- License which applies to GFFT and the specific rights it gives you
- to modify and distribute GFFT, or the no-warranty disclaimer which
- applies to it, refer to the file named COPYING.
-
- Though GFFT is copyrighted under a General Public License and
- the author respects and agrees with the ideas of the Free Software
- Foundation, GFFT is not currently part of project GNU. So please
- direct any inquiries about the program itself to the author, and
- not the Free Software Foundation.
-
- The most important files in this archive are provided with
- icons so you can use them from the Workbench. Two files not
- provided with icons are the the Product-Info and History files.
-
-
- GFFT README TABLE OF CONTENTS
-
- Preface (the long part you just read)
- 1. What can I do with GFFT?
- 2. What features does GFFT have?
- 3. What are my rights to use, modify, and distribute GFFT?
- 4. The trademark and copyright statements
-
-
- 1. What can I do with GFFT?
-
- With GFFT you can explore the world of sound in a new domain--
- the frequency domain.
-
- With GFFT you can "see" what frequencies are present in a
- particular sound, and how they vary over time. This might be
- useful if you are involved in some kind of research, or if you want
- to understand a sound better so that you can synthesize a
- simulation of it.
-
- With GFFT, an audio sampler, and a random noise generator
- (preferrably a pink noise generator), you can analyze the frequency
- response of electronic audio equipment. Add a calibrated
- microphone, and you can also analyze loudspeakers and room
- acoustics. This is where GFFT really shines. Few (if any)
- analyzers are able to achieve the fine resolution or accuracy that
- GFFT can achieve, or compensate for the frequency response of
- ancillary equipment as flexibly as GFFT, or produce hardcopy which
- looks as nice.
-
-
- 2. What are the features of GFFT?
-
- GFFT is an FFT-based spectrum analysis program with many
- features.
-
- GFFT can produce high quality spectrum plots on screen,
- plotter, or printer, or save to Postscript or TeX files, or output
- spectral data in text form to a console or file. (GNUPLOT, a
- separate program by other authors, is required for plotting
- features. GFFT is designed to invoke and control GNUPLOT
- automatically.) It can plot in 2D (Amplitude vs Frequency), or 3D
- (Amplitude vs Frequency vs Time). It allows the selection of
- logarithmic X and/or Y axes, the dB scaling of X, and arbitrary 3D
- rotation. GFFT can show multiple spectra in the same plot, or
- append spectral data bands from earlier sessions.
-
- GFFT provides 8 selectable FFT window types, including
- Blackman-Harris 92 dB. It can apply a special weighting for pink
- noise testing. Smoothing, calibration, ranging, and quantization
- are also available. There are no arbitrary limits to the number of
- frequency bins or smoothing points, or to the length of data which
- can be analyzed.
-
- GFFT is intended to be fairly universal in nature.
- Furthermore, since it is provided under a GNU General Public
- License and distributed with source code, a user with an
- understanding of programming can adapt it to more specialized
- requirements. (I may also be able to help; see below.)
-
- Please be aware that GFFT (and all the code provided with
- GFFT) is not intended for use in applications where error or
- inaccuracy could endanger life or property. There is ABSOLUTELY NO
- WARRANTY, express or implied, concerning the performance or
- accuracy of GFFT. The general no-warranty disclaimer is given in
- the file named COPYING which should be included with this
- distribution.
-
-
- 3. What are my rights to use, modify, and distribute GFFT?
-
- This program is 'free' software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
-
- You should have received a copy of the GNU General Public
- License along with this program (in a file named 'COPYING'); if
- not, write to the Free Software Foundation, Inc., 675 Mass Ave,
- Cambridge, MA 02139, USA. Please do not contact them for any
- other information about this program; they do not necessarily
- know anything about it.
-
-
- 4. The trademark and copyright statements
-
- GFFT, GFFT.HELP, and related contents in this distribution are
- Copyright (C) 1994, 1996 Charles P. Peterson.
-
- 'Workbench', 'Amiga', and 'AmigaGuide' are registered trademarks of
- Amiga Technologies. GNU is a name used by the Free Software
- Foundation, Inc. GNUPLOT is copyright by Thomas Williams and Colin
- Kelley. POST is copyright by Adrian Aylward. All other trademarks
- or copyrights mentioned here or in code or supporting documentation
- are property of their respective owners.
-