FIR Cookbook?
in [DSP]
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From: jeff227 on 6 Dec 2006 12:28 Has anyone come up with a "cookbook" for simple FIR filters similar to RBJ's IIR cookbook? I am looking for audio filters (i.e., mild rolloff, fast compute) using relatively short FIRs (50 coeffs max). Reason for FIR is that I need linear phase. Reason for cookbook is that I need to calculate the coefficients as part of the routine (so the filter will work at different sample rates). Window-based FIRs would probably be most efficient for audio purposes. I have started compiling bits of code for Window-based FIRs but it would nice not to re-invent the wheel if a "cookbook" already exists! Thank you.
From: Rune Allnor on 6 Dec 2006 12:39 jeff227 skrev: > Has anyone come up with a "cookbook" for simple FIR filters similar to > RBJ's IIR cookbook? > > I am looking for audio filters (i.e., mild rolloff, fast compute) using > relatively short FIRs (50 coeffs max). Reason for FIR is that I need > linear phase. Reason for cookbook is that I need to calculate the > coefficients as part of the routine (so the filter will work at different > sample rates). Window-based FIRs would probably be most efficient for > audio purposes. > > I have started compiling bits of code for Window-based FIRs but it would > nice not to re-invent the wheel if a "cookbook" already exists! Cookbooks on FIR filter window designs are all over the place; get an intermediate-level text on DSP (Oppenheim, Schafer & Buck or Proakis & Manolakis). Now, your requirements for the FIR might not go very well with window design. You might have to llok into the Parks-McClellan algorithm to get filters that meet all your specs. Rune
From: Ron N. on 6 Dec 2006 14:00 Rune Allnor wrote: > jeff227 skrev: > > Has anyone come up with a "cookbook" for simple FIR filters similar to > > RBJ's IIR cookbook? > > > > I am looking for audio filters (i.e., mild rolloff, fast compute) using > > relatively short FIRs (50 coeffs max). Reason for FIR is that I need > > linear phase. Reason for cookbook is that I need to calculate the > > coefficients as part of the routine (so the filter will work at different > > sample rates). Window-based FIRs would probably be most efficient for > > audio purposes. > > > > I have started compiling bits of code for Window-based FIRs but it would > > nice not to re-invent the wheel if a "cookbook" already exists! > > Cookbooks on FIR filter window designs are all over the place; get an > intermediate-level text on DSP (Oppenheim, Schafer & Buck or > Proakis & Manolakis). > > Now, your requirements for the FIR might not go very well with > window design. You might have to llok into the Parks-McClellan > algorithm to get filters that meet all your specs. The IIR cookbook filters can be calculated quickly with only a few common transcendental function evaluations or table lookups needed. remez is hardly on the same order if filter generation time is a more important constraint than filter passband/stopband quality. Just off the top of my head, how about a windowed sinc with a pre-calculated window. Change the width of the sinc to change the passband width, Spiral the phase of the sinc to change the center frequency. Seems to require on the order of only a couple table lookups and a few MACs per tap, for an arbitrary (3 degree of freedom) filter with it's quality limited by the window shape. What would be the next better recipe given the same computational time constraints? Is there a recipe that could generate a FIR filter with even less computation? IMHO. YMMV. -- rhn A.T nicholson d.0.t C-o-M
From: Ben Jackson on 6 Dec 2006 16:52 On 2006-12-06, jeff227 <rocksonics(a)earthlink.net> wrote: > I have started compiling bits of code for Window-based FIRs but it would > nice not to re-invent the wheel if a "cookbook" already exists! The ultimate cookbook is Matlab, or the free clone Octave (with the DSP stuff from Octave-forge). You still want the book for the principles, but there's no need to re-implement the design code. -- Ben Jackson AD7GD <ben(a)ben.com> http://www.ben.com/
From: Sastry on 6 Dec 2006 17:58
Also, I think is something like a Handbook of Filter Design or something like that by Sanjit K Mitra. Ben Jackson wrote: > On 2006-12-06, jeff227 <rocksonics(a)earthlink.net> wrote: > > I have started compiling bits of code for Window-based FIRs but it would > > nice not to re-invent the wheel if a "cookbook" already exists! > > The ultimate cookbook is Matlab, or the free clone Octave (with the DSP > stuff from Octave-forge). You still want the book for the principles, > but there's no need to re-implement the design code. > > -- > Ben Jackson AD7GD > <ben(a)ben.com> > http://www.ben.com/ |