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Diffstat (limited to 'third_party/resample/src/resample.h')
| -rw-r--r-- | third_party/resample/src/resample.h | 86 |
1 files changed, 0 insertions, 86 deletions
diff --git a/third_party/resample/src/resample.h b/third_party/resample/src/resample.h deleted file mode 100644 index c09e891b..00000000 --- a/third_party/resample/src/resample.h +++ /dev/null @@ -1,86 +0,0 @@ -/* - * 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 |