/* * FILE: resample.h * * The configuration constants below govern * the number of bits in the input sample and filter coefficients, the  * number of bits to the right of the binary-point for fixed-point math, etc. * */#include "stdefs.h"/* Conversion constants */#define Nhc       8#define Na        7#define Np       (Nhc+Na)#define Npc      (1<<Nhc)#define Amask    ((1<<Na)-1)#define Pmask    ((1<<Np)-1)#define Nh       16#define Nb       16#define Nhxn     14#define Nhg      (Nh-Nhxn)#define NLpScl   13/* Description of constants: * * Npc - is the number of look-up values available for the lowpass filter *    between the beginning of its impulse response and the "cutoff time" *    of the filter.  The cutoff time is defined as the reciprocal of the *    lowpass-filter cut off frequence in Hz.  For example, if the *    lowpass filter were a sinc function, Npc would be the index of the *    impulse-response lookup-table corresponding to the first zero- *    crossing of the sinc function.  (The inverse first zero-crossing *    time of a sinc function equals its nominal cutoff frequency in Hz.) *    Npc must be a power of 2 due to the details of the current *    implementation. The default value of 512 is sufficiently high that *    using linear interpolation to fill in between the table entries *    gives approximately 16-bit accuracy in filter coefficients. * * Nhc - is log base 2 of Npc. * * Na - is the number of bits devoted to linear interpolation of the *    filter coefficients. * * Np - is Na + Nhc, the number of bits to the right of the binary point *    in the integer "time" variable. To the left of the point, it indexes *    the input array (X), and to the right, it is interpreted as a number *    between 0 and 1 sample of the input X.  Np must be less than 16 in *    this implementation. * * Nh - is the number of bits in the filter coefficients. The sum of Nh and *    the number of bits in the input data (typically 16) cannot exceed 32. *    Thus Nh should be 16.  The largest filter coefficient should nearly *    fill 16 bits (32767). * * Nb - is the number of bits in the input data. The sum of Nb and Nh cannot *    exceed 32. * * Nhxn - is the number of bits to right shift after multiplying each input *    sample times a filter coefficient. It can be as great as Nh and as *    small as 0. Nhxn = Nh-2 gives 2 guard bits in the multiply-add *    accumulation.  If Nhxn=0, the accumulation will soon overflow 32 bits. * * Nhg - is the number of guard bits in mpy-add accumulation (equal to Nh-Nhxn) * * NLpScl - is the number of bits allocated to the unity-gain normalization *    factor.  The output of the lowpass filter is multiplied by LpScl and *    then right-shifted NLpScl bits. To avoid overflow, we must have  *    Nb+Nhg+NLpScl < 32. */int resample(			/* number of output sample returned */    double factor,		/* factor = Sndout/Sndin */    int    infd,		/* input and output file descriptors */    int    outfd,    int inCount,		/* number of input samples to convert */    int outCount,		/* number of output samples to compute */    int nChans,			/* number of sound channels (1 or 2) */    BOOL interpFilt,		/* TRUE means interpolate filter coeffs */    int fastMode,		/* 0 = highest quality, slowest speed */    BOOL largeFilter,		/* TRUE means use 65-tap FIR filter */    char *filterFile		/* NULL for internal filter, else filename */);//#define MUS_SAMPLE_TYPE mus_sample_t; // more incompatible changes to sndlib