Simplest way to implement FIR filter in C/C++ What's the simplest way to implement a FIR filter in C/C++ ?

(I don't want to have to use a third-party software like Matlab or Octave in order to compute the coefficiens because I have to use different filters on thousand of files, with different frequencies for each file.)

Thus, is there a ready-to-use C/C++ DSP library with functions like file.FIR_NotchFilter(frequency,Qfactor) ? or something similar ?
(commercial or opensource) 

Thanks a lot in advance.

PS1 : I see that there is http://aquila-dsp.org, but there are no binary releases yet, and for older version, it seems difficult to use it

PS2 : A really ready-to-use solution exists for IIR filters : https://github.com/vinniefalco/DSPFilters

// Create a Chebyshev type I Band Stop filter of order 3
Dsp::SimpleFilter &lt;Dsp::ChebyshevI::BandStop &lt;3&gt;, 2&gt; f;
f.setup (3,    // order
     44100,// sample rate
     4000, // center frequency
     880,  // band width
     1);   // ripple dB
f.process (numSamples, arrayOfChannels);
Have you considered using the Parks McClellan algorithm to generate your FIR filters. The source code for it is available on several sites in Fortran or C.

The original Fortran code is available on Wikipedia.

Here are two sources for C code


Github/scipy 
Iowa Hills


You said you were trying to understand filters, so let me explain that the Parks McClellan algorithm is a classic. It was developed in the early 70's, and is still considered to be one of the best FIR design algorithms available.