Short: FIR Filter Designer V2.1 Author: harald.zottmann@t-online.de Uploader: harald.zottmann@t-online.de Type: misc/sci Replaces misc/sci/FIRDesign2* Version: 2.1 FIR Filter Designer =================== This is the sixth Aminet release of the FIR Filter Designer. The program designs optimized Finite Impulse Response Filters. Amiga OS 3.x is required. The program requires a minimum Workbench screen size of 640x400. The FIR Filters designed by the program FIR Filter Designer V2.0 can be loaded by the program AudioLab16 from Maurizio Ciccione. AudioLab16 can be found on the Aminet in the directory /mus/edit. The problem of designing finite impulse response (FIR) digital filters experienced great activity in the early 1970`s. Most of this work was directed at the problem of optimal filter design, in the weighted Chebyshev sense. The algorithm for this program, by McClellan, Parks and Rabiner, will design the optimal Chebyshev approximation for linear phase filters. The Chebyshev optimization is done very efficiently by means of the Remez exchange algorithm, and this particular FIR filter design program has found wide use. The window method filter design process is based upon Fourier series. It is possible to represent a frequency function as a Fourier series, whose coefficients represent the coefficients of the filter. To form a casual filter, the Fourier series is truncated and shifted. Truncating the Fourier series causes a phenomenon called the "Gibbs effect" - a spike occurs wherever there is a discontinuity in the desired magnitude of the filter. To counteract this, the filter coefficients are convolved in the frequency domain with the spectrum of a window function, thus smoothing the edge transitions at any discontinuity. This convolution in the frequency domain is equivalent to multiplying the filter coefficients with the window coefficients in the time domain. History ======= Date Version Type Comments ---- ------- ---- -------- 06/02/98 V2.10 Release Sixth AMINET Release - Fixed a serious bug with big font sizes - New ToolType for FONTNAME and FONTSIZE 20/01/98 V2.00 Release Fifth AMINET Release - Window method filter design - Requires OS3.x now - Improved GUI - Progress bar - Extended documentation - Recompiled with SAS/C V6.58 20/07/96 V1.20 Release Fourth AMINET Release - ToolType support - Filterlength now up to 512 taps - Internal improvements - Displays floating point errors - View log file with external viewer - Displays also the corrected phase 01/05/96 V1.10 Release Third AMINET Release - Versions for: MC 68000 MC 68020 MC 68040 - Updated the installer script - Now compatible with AudioLab16 - Grids in the Prism window - Some redesigns and optimizations - Fixed Bug with too small workbench 29/11/95 V1.01 Release Second AMINET Release - Fixed several Enforcer Hits - Fixed Bug with not updating gadgets - Recompiled with SAS/C V6.56 - Less Shareware Requesters - Installer Script - Added Pattern in Filerequester - More Examples 21/07/95 V1.00 Release First AMINET Release ============================= Archive contents ============================= Original Packed Ratio Date Time Name -------- ------- ----- --------- -------- ------------- 588 121 79.4% 20-May-94 14:56:20 +Bandpass.FIR 588 81 86.2% 20-May-94 15:12:44 +Differentiator.FIR 1379 670 51.4% 07-Feb-98 00:52:50 +DISCLAIMER.TXT 36975 11309 69.4% 07-Feb-98 01:03:12 +FIRDesigner.guide 468 223 52.3% 09-Dec-97 23:57:44 +FIRDesigner.guide.info 704 355 49.5% 16-Jul-96 21:37:24 +FIRDesigner.install.info 4181 1553 62.8% 07-Feb-98 00:51:08 +FIRDesigner.readme 1391 504 63.7% 16-Jul-96 21:37:26 +FIRDesigner.readme.info 96520 48945 49.2% 07-Feb-98 01:09:36 +FIRDesigner_020 588 91 84.5% 29-Nov-95 19:24:40 +Highpass.FIR 588 85 85.5% 20-May-94 15:14:10 +Hilbert.FIR 588 92 84.3% 29-Nov-95 19:23:04 +Lowpass.FIR 588 100 82.9% 29-Nov-95 19:28:32 +Multipass.FIR 1592 454 71.4% 07-Feb-98 00:53:54 +ORDERFORM.TXT 673 317 52.8% 27-Nov-97 22:29:38 FIRDesigner.info 104 61 41.3% 03-Dec-97 18:33:14 +Bandpass.WFIR 589 113 80.8% 26-Jun-96 18:55:40 +Bandpass128.FIR 1415 529 62.6% 16-Jul-96 21:37:26 +DISCLAIMER.TXT.info 103976 50897 51.0% 07-Feb-98 00:47:30 +FIRDesigner 6663 552 91.7% 07-Feb-98 01:02:18 +FIRDesigner.info 7831 1705 78.2% 07-Feb-98 00:53:18 +FIRDesigner.install 96512 49310 48.9% 07-Feb-98 01:17:32 +FIRDesigner_040 104 60 42.3% 03-Dec-97 18:53:42 +Highpass.WFIR 104 62 40.3% 03-Dec-97 19:02:18 +Lowpass.WFIR 588 101 82.8% 29-Nov-95 19:34:10 +Notch.FIR 1415 527 62.7% 16-Jul-96 21:37:26 +ORDERFORM.TXT.info 104 64 38.4% 03-Dec-97 18:42:40 +Stopband.WFIR -------- ------- ----- --------- -------- 366816 168881 53.9% 07-Feb-98 21:05:08 27 files