25 lines
663 B
C
25 lines
663 B
C
/*
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The function to compute the cos tables at runtime or for pregeneration.
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copyright ?-2021 by the mpg123 project - free software under the terms of the LGPL 2.1
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see COPYING and AUTHORS files in distribution or http://mpg123.org
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initially written by Michael Hipp (in tabinit.c).
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The type clreal is either double or float, COS() is cos() or cosf() for runtime.
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*/
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void init_costabs(void)
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{
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clreal *cpnts[] = { cos64,cos32,cos16,cos8,cos4 };
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int i,k,kr,divv;
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clreal *costab;
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for(i=0;i<5;i++)
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{
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kr=0x10>>i; divv=0x40>>i;
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costab = cpnts[i];
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for(k=0;k<kr;k++)
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costab[k] = 1.0 / (2.0 * COS(M_PI * ((clreal) k * 2.0 + 1.0) / (clreal) divv));
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}
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}
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