Prof

							        Prof. Brian Evans: Real-time DSP course online at
        http://www.ece.utexas.edu/~bevans/courses/realtime/.

        TechOnLine (http://www.techonline.com/): Courses on various topics.

        Engineering Productivity Tools Ltd. (http://www.eptools.com/tn/index.htm):
        Technical notes on various topics (FFT, Sensor arrays, etc.).

        BORES Signal Processing DSP course.
        (http://www.bores.com/courses/intro/index.htm): Introduction courses to DSP.

        TI has a centralized training site where DSP designers can access all of TI's
        training webcasts, workshops and seminars. It can be found at
        www.dspvillage.ti.com/trainingpr2. It covers TI DSP, tools, software and
        applications. Analog training is also included.

        TI also has a site designed to help new DSP users (primarily new TI DSP users)
        get started with their designs: http://www.dspvillage.ti.com/cocostu.

3: Where can I get free software for general DSP?
Updated 05/06/02

        The packages listed below are mostly not oriented for use with a specific DSP
        processor. See the later sections in the FAQ for software relevant to a particular
        programmable DSP chip.

Q1.3.1: DSP Packages for MATLAB
Updated 05/06/02
        FOR STUDENTS IN THE US AND CANADA: The MATLAB Student Version,
        available from The MathWorks, is a full-featured version of MATLAB and
       includes Simulink (with model sizes up to 300 blocks) and the Symbolic Math
       toolbox. It is available for Windows and Linux. See
       http://www.mathworks.com/products/studentversion/.

MATLAB user's group public domain extensions to MATLAB

Description:
       The MATLAB Digest is issued at irregular intervals based on the number of
       questions and software items contributed by users. To subscribe to the newsletter,
       send mail to subscribe@mathworks.com. To make submissions to the digest,
       please send to hwilson@ua1vm.ua.edu with a subject: "DIG" and description.
To obtain:
       Some MATLAB tools are available on the web at http://www.mathworks.com, or
       via anonymous ftp at ftp://ftp.mathworks.com/.

Wavelet Tools

Description:
       There is a set of Wavelet Tools available for MATLAB, see Section 2.9 of this
       FAQ.

Communications Toolbox

Description:
       We have developed a "Communications Toolbox" based on the MATLAB code
       for classroom use. It is used by students taking a 4th year communications course
       where the emphasis is on digital coding of waveforms and on digital data
       transmission systems. The MATLAB code that constitutes this toolbox has been
       in use for over two years.

       There are close to 100 "M-files" that implement various functions. Some of them
       are quite simple and are based on existing MATLAB M-files. But a great many of
       them has been created from scratch. We also prepared a lab manual (in TEX
       format) for the 7 simulations which the students perform as the lab component of
       this course. The topics of these simulations are:

                Probability Theory
                Random Processes
                Quantization
                Binary Signalling Formats
                Detection
                Digital Modulation
                Digital Communication

To obtain:
        M-files (MATLAB 4.2) is available in:
        ftp://ftp.mathworks.com/pub/contrib/v4/misc/comm_tbx/

        The complete manual in Postscript format is available at
        ftp://ftp.mathworks.com/pub/contrib/v4/misc/comm_tbx/comm_tbx.manual.ps.
        [Mehmet Zeytinoglu, mzeytin@ee.ryerson.ca]

Digital Filter Package (DFP)

Description:
       The Digital Filter Package is a GUI front-end to digital filter design with
       MATLAB. DFP extends the basic digital filter design functionality of MATLAB
       in two important ways:

                Filter coefficients can be quantized. This feature is important if the filter is
                 to be implemented on a fixed-point DSP processor.
                DFP generates assembly-language code for the designed digital filter. In
                 the current release of DFP, this option is only available for the Motorola
                 DSP56xxx family.

For more information:
      http://www.ee.ryerson.ca:8080/~mzeytin/dfp/index.html. [Mehmet Zeytinoglu,
        mzeytin@ee.ryerson.ca]

Implementations of the CELP Federal Standard 1016 Speech Coder and LPC-10e
Speech Coder

To obtain:
       http://www.cysip.com/dsplinks.html. [Andreas Spanias, spanias@asu.edu]

GSM Routines

Description:
       Chris Stratford has placed GSM-related MATLAB code online, including routines
       for GMSK modulation and Viterbi equalization.
To obtain:
       http://www.stratfordc.free-online.co.uk.

Q1.3.5: Text to Speech Conversion Software
Updated 1/7/97
        Free (but not public domain) text to speech conversion software is available via
        anonymous ftp from wilma.cs.brown.edu in the pub directory as speak.tar.Z. It
        will compile and run on a SPARC's built-in audio after modifying speak.c with
        the path of your libaudio.h (e.g., /usr/demo/SOUND/libaudio.h). It's a simple
        phoneme concatenation system with commensurate synthesized speech quality (a
       directory of phoneme audio files is included). [Joe Campbell,
       jpcampb@afterlife.ncsc.mil]

       A public domain version of the same Naval Research Lab text to phoneme rules
       can be obtained from:

       ftp://svr-ftp.eng.cam.ac.uk/pub/comp.speech/syntheses/english2phoneme.tar.gz

       The comp.speech FTP site includes a speech synthesis directory at ftp://svr-
       ftp.eng.cam.ac.uk/pub/comp.speech/synthesis. The main package is "rsynth"
       which is a complete text to speech synthesis system. Several component packages
       are also present. "textnorm" converts non-words such as digit strings into words
       (e.g. 1000 to ONE THOUSAND). "english2phoneme" does some of the same but
       its main functionality is to guess an appropriate phoneme sequence for each word.
       "klatt" takes a parametric form that describes each phoneme and converts it to a
       waveform. Other packages exist in the same directory to edit and visualise the
       klatt parameters. [Tony Robinson, ajr@softsound.com]



Q1.3.6: Filter Design Software
Updated Sep 9 2004

      There are many filter design programs available via anonymous FTP or by HTTP.
       The following are summarized here and discussed in greater detail below:
          o August 1992 IEEE Trans. on Signal Processing: METEOR FIR filter
              design program.
          o DFiltFIR and DFiltInt FIR filter design program.
          o Netlib IIR filter design.
          o IEEE Press "Programs for Digital Signal Processing".
          o Tod Schuck's near-optimal Kaiser-Bessel program.
          o Brian Evans' and Niranjan Damera-Venkata's packages for Matlab and
              Mathematica.
          o ScopeFIR.
          o FilterExpress.
          o Charles Poynton's filter design resource page.
          o Juhana Kouhia's hotlist.
          o Alex Matulich's recipes for compiling 2-pole digital filters.

      The August 92 issue of IEEE Transactions on Signal Processing includes a paper
       entitled "METEOR: A Constraint-Based FIR Filter Design Program" by Kenneth
       Steiglitz, Thomas W. Parks and James F. Kaiser. The authors describe an FIR
       design program which allows specification of the target frequency response
       characteristics in a fairly generalized and flexible way. As well as designing
       filters, the program can optimize filter lengths and push band limits.
    The source for the programs (meteor.p, form.p, meteor.c, and form.c) and the
    METEOR paper as a postscript file may be found at http://www.
    music.Princeton.edu/classes/class.html. The programs were originally written in
    Pascal and then evidentally run through p2c to produce the C versions; all the
    necessary Pascal library stuff is included in the C code and they built error-free
    out of the box for me on an SGI machine.

    There is no manual. The paper includes instructions on running the programs.
    [Steve Clift, clift@mail.anacapa.net]

    Weimin Liu has created a Windows 95 interface to the Meteor program, which
    can be downloaded from http://www.nyx.net/~wliu/filter.html.

   Other free filter design packages are DFiltFIR and DFiltInt. DFiltFIR designs
    minimax approximation FIR filters. It uses the algorithm developed by
    McClelland and Parks and incorporates constraints on the response as proposed
    by Grenez. DFiltInt designs minimum mean-square error FIR interpolating filters.
    The design specification is in terms of a tabulated power spectrum model for the
    input signal.

    The packages are available from
    http://www.tsp.ece.mcgill.ca/Docs/Software/FilterDesign/FilterDesign.html or
    directly via anonymous ftp from ftp://ftp.tsp.ece.mcgill.ca/TSP/FilterDesign/.

    Another package, libtsp, is a library of C-language routines for signal processing.
    The package is available from
    http://www.tsp.ece.mcgill.ca/reports/Software/libtsp/libtsp.html or directly via
    anonymous ftp from ftp://ftp.tsp.ece.mcgill.ca/pub/libtsp/ [Peter Kabal,
    kabal@ECE.McGill.CA]

   Another source is netlib: "A free program to design IIR Butterworth, Chebyshev,
    and Cauer (elliptic) filters, in any of lowpass, bandpass, band reject, and high pass
    configurations, is available in netlib (e.g., netlib.bell-labs.com) as the file
    netlib/cephes/ellf.shar.Z. By email to netlib@netlib.bell-labs.com the request
    message text is `send ellf from cephes'. The URL is http://www.netlib.org. [Stephen
    Moshier, moshier@world.std.com]

   The Fortran source code from the IEEE Press book "Programs For Digital Signal
    Processing" is available by anonymous ftp from
    ftp://soma.crl.mcmaster.ca/pub/IEEE/software/dsp.zip or
    ftp://soma.crl.mcmaster.ca/pub/IEEE/software/dsp.tar.gz. It includes FIR and IIR
    filter design software, FFT subroutines, interpolation programs, a coherence and
    cross-spectral estimation program, linear prediction analysis programs, and a
    frequency domain filtering program. There is also a C/C++ version of the
    McClellan-Parks-Rabiner FIR filter design program available from
    ftp://ftp.uu.net/usenet/comp.sources.misc/volume22/fir/part01.Z
    This program was created and tested using Borland C++ 2.0. This requires a
    pretty reasonable C++ compiler - it is reported that QuickC (not C++) won't do it.
    [Witold Waldman, from Charles Owen at mgcbo@uxa.ecn.bgu.au; also Andrew Ukrainec,
    ukrainec@InfoUkes.com]

   I have developed a MATLAB (vers 4.0 for Windows) program that allows for the
    frequency domain design of the "near optimal" Kaiser-Bessel window. The
    program is based upon the three closed form equations developed by Kaiser and
    Schafer in 1981 that allow for the specification of the time domain window
    length, and the frequency domain mainlobe width and relative sidelobe amplitude.
    For signal processing applications where the spectral content of the windowing
    function is critical so as not to mask adjacent spectra such as radar signal
    processing applications where a weak target return adjacent to a strong target
    return could be easily masked by a windowing function that resolves poorly in
    frequency; this program allows complete frequency domain specification of the
    spectral characteristics of the windowing function. The current version of this
    program allows for the user to specify the two frequency domain parameters of
    mainlobe width and relative sidelobe amplitude and lets the window length fall
    out as the dependent variable. The program is easily modified to allow for any
    two parameters to be selected and allowing the third to be determined as a result.

    This program will output to an ASCII file the window coefficients that can be
    easily dumped to an EPROM or included in a program. It also generates both time
    and frequency domain graphs so that the user can visually verify the widow
    record length and spectral content. I will gladly provide any interested parties
    with my MATLAB code.

    Tod M. Schuck
    Lockheed Martin NE&SS
    Moorestown, NJ 08060
    e-mail: tod.m.schuck@lmco.com

   Filter Optimization Packages for Matlab and Mathematica, version 1.1 by Brian
    L. Evans and Niranjan Damera-Venkata, Dept. of ECE, The University of Texas
    at Austin. Available from
    http://www.ece.utexas.edu/~bevans/projects/filters/syn_filter_software.html .

    We have released a set of Matlab packages to optimize the following
    characteristics of analog filter designs simultaneously:

        1.   magnitude response
        2.   linear phase in the passband
        3.   peak overshoot in the step response
        4.   quality factors (Q)
    subject to constraints on the same characteristics. The Matlab packages take about
    10 seconds for fourth-order filters and 3 minutes for eighth-order filters to run on
    a 167-MHz Sun Ultra-2 workstation.

    We use the symbolic mathematics environment Mathematica to describe the
    constrained non-linear optimization problem formally, derive the gradients of the
    cost function and constraints, and synthesize the Matlab code to perform the
    optimization. In the public release, we provide the Matlab to optimize analog IIR
    filters of fourth, sixth, and eighth orders. Using the Mathematica formulation,
    designers can add new measures and constraints, such as capacitance spread for
    integrated circuit layout, and regenerate the Matlab code.

    We describe the framework in [1]. An earlier version of the framework is
    described in [2]. We plan to extend this framework to digital IIR filters.

    [1] N. Damera-Venkata, B. L. Evans, M. D. Lutovac, and D. V. Tosic, Joint
    Optimization of Multiple Behavioral and Implementation Properties of Analog
    Filter Designs, Proc. IEEE Int. Sym. on Circuits and Systems, Monterey, CA,
    May 31 - Jun. 3, 1998, vol. 6, pp. 286-289.
    http://www.ece.utexas.edu/~bevans/papers/1998/filter_optimization/.

    [2] B. L. Evans, D. R. Firth, K. D. White, and E. A. Lee, Automatic Generation of
    Programs That Jointly Optimize Characteristics of Analog Filter Designs, Proc.
    of European Conf. on Circuit Theory and Design, Istanbul, Turkey, August 27-31,
    1995, pp. 1047-1050.
    http://ptolemy.eecs.berkeley.edu/publications/papers/95/filter_design_ecctd95/

    [Brian Evans, bevans@combo.ece.utexas.edu]

   ScopeFIR is a FIR filter design tool for Windows 95/NT which designs complex
    FIR filters using the Parks-McClellan algorithm or windowing. It can then mix,
    scale, quantize, and edit the FIR coefficients. It creates a wide variety of impulse
    and frequency response plots, and supports many data file formats, including TI
    assembly and ADI PM. Shareware with a 60-day trial period, available from
    http://www.iowegian.com/scopefir.htm.

    [Grant Griffin, grant.griffin@iowegian.com]

   FilterExpress is a free filter synthesis tool for Windows. It supports the design and
    analysis of IIR, FIR and multirate FIR filters. It is available for download from
    http://www.systolix.co.uk/swdownload.htm.

   DSP Design Performance provides Java applets generating different filters. The
    applets can be found at http://www.nauticom.net/www/jdtaft.

   Charles Poynton has an extensive list of hot-links to filter design resources on the
    web at http://www.inforamp.net/~poynton/Poynton-dsp.html.
       Juhana Kouhia has an extensive list of links at
        http://www.funet.fi/~kouhia/hotlist-dsp.html.

       Alex Matulich has compiled recipes (step by step instructions) for coding three
        kinds of 2-pole digital filters, both low-pass and high-pass, complete with
        correction factors to ensure that the 3 dB cutoff frequency stays where you put it
        when you cascade filters of the same type together.

        Alex has made these recipes available here:
        http://unicorn.us.com/alex/2polefilters.html

        The recipes cover Butterworth, Critically-Damped, and Bessel filters. Alex also
        includes test results; i.e., plots of actual frequency response and step-function
        temporal response for each filter.



Q1.3.7: Audio effects
Updated 2/11/02

Harmony Central

        Harmony Central publishes some of the source code for its synthesis and audio
        processing program at http://www.harmony-
        central.com/Computer/Programming/. The code may be used in public releases,
        but Harmony Central asks you to credit the author and possibly make the product
        available for free or publish any modified code.

Music-DSP Source Code Archive

        Musicdsp.org is a collection of data gathered for the music dsp community. It
        includes code for wavetable synthesis, dithering, guitar feedback, and many other
        effects and algorithms.

        http://www.musicdsp.org/

[Steve Horne, steve@lurking.demon.co.uk]