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Commit c802da93 authored by Glenn Kasten's avatar Glenn Kasten Committed by Android Git Automerger
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am 108e1961: Merge "Tweak the SINC resampler parameters and double the... 

am 108e1961: Merge "Tweak the SINC resampler parameters and double the performance. It\'s using about 10% CPU in the worse case now."

* commit '108e1961':
  Tweak the SINC resampler parameters and double the performance. It's using about 10% CPU in the worse case now.
parents a5c85850 108e1961

tools/resampler_tools/fir.cpp

+3 −3
Original line number Diff line number Diff line
@@ -62,10 +62,10 @@ int main(int argc, char** argv) 


    // cut off frequency ratio Fc/Fs

    // The bigger the stop-band, the less coefficients we'll need.

    double Fcr = 22050.0 / 48000.0;

    double Fcr = 20000.0 / 48000.0;



    // nzc is the number of zero-crossing on one half of the filter

    int nzc = 16;

    int nzc = 8;

    

    // alpha parameter of the kaiser window

    // Larger numbers reduce ripples in the rejection band but increase
@@ -80,7 +80,7 @@ int main(int argc, char** argv) 
    //    80 dB    7.865

    //    90 dB    8.960

    //   100 dB   10.056

    double alpha = 10.056;	// -100dB stop-band attenuation

    double alpha = 7.865;	// -80dB stop-band attenuation

    

    // 2^nz is the number coefficients per zero-crossing

    // (int theory this should be 1<<(nc/2))