Type : LP, HP, BP, BS, Shelf, Notch, Boost. References : Posted by thevinn at yahoo dot com. Code : /*"A Collection of Useful C++ Classes for Digital Signal Processing"By Vincent Falco. Please direct all comments to either the music- dsp mailing list orthe DSP and Plug- in Development forum: http: //music. Support is provided for performing N- order Dsp floating point filteroperations on M- channel data with a caller specified floating point type. The implementation breaks a high order IIR filter down into a series ofcascaded second order stages. Tests conclude that numerical stability ismaintained even at higher orders. For example the Butterworth low passfilter is stable at up to 5. Processing functions are provided to use either Direct Form I or Direct. Form II of the filter transfer function. Direct Form II is slightly fasterbut can cause discontinuities in the output if filter parameters are changedduring processing. Direct Form I is slightly slower, but maintains fidelityeven when parameters are changed during processing. To support fast parameter changes, filters provide two functions foradjusting parameters. A high accuracy Setup() function, and a fasterform called Setup. Fast() that uses approximations for trigonometricfunctions. The approximations work quite well and should be suitable formost applications. Channels are stored in an interleaved format with M samples per framearranged contiguously. A single class instance can process all M channelssimultaneously in an efficient manner. A 'skip' parameter causes theprocessing function to advance by skip additional samples in the destinationbuffer in between every frame. Through manipulation of the skip paramter itis possible to exclude channels from processing (for example, only processingthe left half of stereo interleaved data).For multichannel data which isnot interleaved, it will be necessary to instantiate multiple instance ofthe filter and set skip=0. . There are a few other utility classes and functions included that may prove useful. Classes: Complex. Cascade. Stages. Biquad. Biquad. Low. Pass. Biquad. High. Pass. Biquad. Band. Pass. Biquad. Band. Pass. Biquad. Band. Stop. Biquad. All. Pass. Biquad. Peak. Eq. Biquad. Low. Shelf. Biquad. High. Shelf. Pole. Filter. Butterworth. Butter. Low. Pass. Our latest hotfix (8.0.67.102) was released on Sep 26, 2017 and is a rollup of issues addressed since the last General Availability Release. Active subscribers of. 1 pole LPF for smooth parameter changes Type : 1-pole LPF class References : Posted by [email protected] Notes : This is a very simple class that I'm using in my. Disk_image is a raw hard disk image for IDE hard disk 0. Some targets do not need a disk image. 2.3.1 Standard options-h. Display help and exit -version. Butter. High. Pass. Butter. Band. Pass. Butter. Band. Stop. Chebyshev. 1Cheby. Low. Pass. Cheby. High. Pass. Cheby. Band. Pass. Cheby. Band. Stop. Chebyshev. Cheby. 2Low. Pass. Cheby. 2High. Pass. Cheby. 2Band. Pass.Cheby. 2Band. Stop.Envelope. Follower. . Auto. Limiter. Functions: zero()copy()mix()scale() interleave()deinterleave()Order for Pole.Filter derived classes is specified in the number of poles,except for band pass and band stop filters, for which the number of pole pairsis specified. For some filters there are two versions of Setup(), the one called. Setup. Fast() uses approximations to trigonometric functions for speed. Open Iv 0 8 Beta Build 16384 TileThis is an option if you are doing frequent parameter changes to the filter. There is an example function at the bottom that shows how to use the classes. Filter ideas are based on a java applet (http: //www. Paul Falstad. All of this code was written by the author Vincent Falco except where marked.- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -License: MIT License (http: //www. Copyright (c) 2. 00. Vincent Falco. Permission is hereby granted, free of charge, to any person obtaining a copyof this software and associated documentation files (the "Software"), to dealin the Software without restriction, including without limitation the rightsto use, copy, modify, merge, publish, distribute, sublicense, and/or sellcopies of the Software, and to permit persons to whom the Software isfurnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included inall copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS ORIMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THEAUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHERLIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS INTHE SOFTWARE.**//*To Do: - Shelving, peak, all- pass for Butterworth, Chebyshev, and Elliptic. The Biquads have these versions and I would like the others to have themas well. It would also be super awesome if higher order filters couldhave a "Q" parameter for resonance but I'm not expecting miracles, itwould require redistributing the poles and zeroes. But if there'sa research paper or code out there.. I could incorporate it. - Denormal testing and fixing I'd like to know if denormals are a problem. And if so, it would be niceto have a small function that can reproduce the denormal problem. Thisway I can test the fix under all conditions. I will include the functionas a "unit test" object in the header file so anyone can verify itscorrectness. But I'm a little lost. - Optimized template specializations for stages=1, channels={1,2} There are some pretty obvious optimizations I am saving for "the end". I don't want to do them until the code is finalized. - Optimized template specializations for SSE, other special instructions - Optimized trigonometric functions for fast parameter changes - Elliptic curve based filter coefficients - More utility functions for manipulating sample buffers - Need fast version of pow( 1. DSP_FILTER__#define __DSP_FILTER__#include < cmath> #include < cfloat> #include < assert. DSP_USE_STD_COMPLEX#ifdef DSP_USE_STD_COMPLEX#include < complex> #endif#define DSP_SSE3_OPTIMIZED#ifdef DSP_SSE3_OPTIMIZED//#include < xmmintrin. Dsp{//- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -// WARNING: Here there be templates//- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- - //- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -//// Configuration////- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- - // Regardless of the type of sample that the filter operates on (e. This controls the underlying// type used for calculations: typedef double Calc. T; typedef int Int. Must be 3. 2 bitstypedef __int. Int. 64; // Must be 6. This is used to prevent denormalization. Calc. T vsa=1. 0 / 4. Calc. T as float // These constants are so important, I made my own copy. If you improve// the resolution of Calc. T be sure to add more significant digits to these.Calc. T k. Pi =3.Calc. T k. Pi_2 =1. Windows 7 October X64 X86 Updates On Hurricane here. Calc. T k. Ln. 2 =0.Calc. T k. Ln. 10 =2.Some functions missing from < math.T> inline T acosh( T x ){return log( x+: :sqrt(x*x- 1) ); } //- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -//// Fast Trigonometric Functions////- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- - // Three approximations for both sine and cosine at a given angle.// The faster the routine, the larger the error.// From http: //lab. Tuned for maximum pole stability. This one breaks down considerably at the higher angles. It is// included only for educational purposes. Calc. T r, Calc. T *sn, Calc. T *cs ){const Calc. T c=0. 7. 07. 10. Calc. T v=(2- 4*c)*r*r+c; if(r< k. Pi_2){*sn=v+r; *cs=v- r; }else{*sn=r+v; *cs=r- v; }} // Lower precision than : :fastsincos() but still decentinline void fastersincos( Calc. T x, Calc. T *sn, Calc. T *cs ){//always wrap input angle to - PI. PIif (x < - k. Pi) x += 2*k. Pi; else if (x > k. Pi) x - = 2*k. Pi; //compute sineif (x < 0) *sn = 1. PI/2) = cos(x)x += k. Pi_2; if (x > k. Pi ) x - = 2*k. Pi; if (x < 0) *cs = 1. Slower than : :fastersincos() but still faster than// sin(), and with the best accuracy of these routines. Calc. T x, Calc. T *sn, Calc. T *cs ){Calc. T s, c; //always wrap input angle to - PI. PIif (x < - k. Pi) x += 2*k. Pi; else if (x > k. Pi) x - = 2*k. Pi; //compute sineif (x < 0){s = 1. PI/2) = cos(x)x += k. Pi_2; if (x > k.
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