mirror of
https://github.com/DrBeef/QuestZDoom.git
synced 2025-03-06 09:21:22 +00:00
107 lines
2.7 KiB
C
107 lines
2.7 KiB
C
/*
|
|
|
|
* Revision 1.2 1996/08/20 20:28:05 jaf
|
|
* Removed all static local variables that were SAVE'd in the Fortran
|
|
* code, and put them in struct lpc10_encoder_state that is passed as an
|
|
* argument.
|
|
*
|
|
* Removed init function, since all initialization is now done in
|
|
* init_lpc10_encoder_state().
|
|
*
|
|
* Revision 1.1 1996/08/19 22:32:04 jaf
|
|
* Initial revision
|
|
*
|
|
|
|
*/
|
|
|
|
/* -- translated by f2c (version 19951025).
|
|
You must link the resulting object file with the libraries:
|
|
-lf2c -lm (in that order)
|
|
*/
|
|
|
|
#include "f2c.h"
|
|
|
|
extern int hp100_(real *speech, integer *start, integer *end,
|
|
struct lpc10_encoder_state *st);
|
|
extern int inithp100_(void);
|
|
|
|
/* ********************************************************************* */
|
|
|
|
/* HP100 Version 55 */
|
|
|
|
/* ********************************************************************* */
|
|
|
|
/* 100 Hz High Pass Filter */
|
|
|
|
/* Jan 92 - corrected typo (1.937148 to 1.935715), */
|
|
/* rounded coefficients to 7 places, */
|
|
/* corrected and merged gain (.97466**4), */
|
|
/* merged numerator into first two sections. */
|
|
|
|
/* Input: */
|
|
/* start, end - Range of samples to filter */
|
|
/* Input/Output: */
|
|
/* speech(end) - Speech data. */
|
|
/* Indices start through end are read and modified. */
|
|
|
|
/* This subroutine maintains local state from one call to the next. If */
|
|
/* you want to switch to using a new audio stream for this filter, or */
|
|
/* reinitialize its state for any other reason, call the ENTRY */
|
|
/* INITHP100. */
|
|
/* Subroutine */ int hp100_(real *speech, integer *start, integer *end,
|
|
struct lpc10_encoder_state *st)
|
|
{
|
|
/* Temporary local copies of variables in lpc10_encoder_state.
|
|
I've only created these because it might cause the loop below
|
|
to execute a bit faster to access local variables, rather than
|
|
variables in the lpc10_encoder_state structure. It is just a
|
|
guess that it will be faster. */
|
|
|
|
real z11;
|
|
real z21;
|
|
real z12;
|
|
real z22;
|
|
|
|
/* System generated locals */
|
|
integer i__1;
|
|
|
|
/* Local variables */
|
|
integer i__;
|
|
real si, err;
|
|
|
|
/* Arguments */
|
|
/* Local variables that need not be saved */
|
|
/* Local state */
|
|
/* Parameter adjustments */
|
|
if (speech) {
|
|
--speech;
|
|
}
|
|
|
|
/* Function Body */
|
|
|
|
z11 = st->z11;
|
|
z21 = st->z21;
|
|
z12 = st->z12;
|
|
z22 = st->z22;
|
|
|
|
i__1 = *end;
|
|
for (i__ = *start; i__ <= i__1; ++i__) {
|
|
si = speech[i__];
|
|
err = si + z11 * 1.859076f - z21 * .8648249f;
|
|
si = err - z11 * 2.f + z21;
|
|
z21 = z11;
|
|
z11 = err;
|
|
err = si + z12 * 1.935715f - z22 * .9417004f;
|
|
si = err - z12 * 2.f + z22;
|
|
z22 = z12;
|
|
z12 = err;
|
|
speech[i__] = si * .902428f;
|
|
}
|
|
|
|
st->z11 = z11;
|
|
st->z21 = z21;
|
|
st->z12 = z12;
|
|
st->z22 = z22;
|
|
|
|
return 0;
|
|
} /* hp100_ */
|