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+/*
+
+$Log$
+Revision 1.15 2004/06/26 03:50:14 markster
+Merge source cleanups (bug #1911)
+
+Revision 1.14 2003/02/12 13:59:15 matteo
+mer feb 12 14:56:57 CET 2003
+
+Revision 1.1.1.1 2003/02/12 13:59:15 matteo
+mer feb 12 14:56:57 CET 2003
+
+Revision 1.2 2000/01/05 08:20:39 markster
+Some OSS fixes and a few lpc changes to make it actually work
+
+ * 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"
+
+#ifdef P_R_O_T_O_T_Y_P_E_S
+extern int hp100_(real *speech, integer *start, integer *end,
+ struct lpc10_encoder_state *st);
+extern int inithp100_(void);
+#endif
+
+/* ********************************************************************* */
+
+/* HP100 Version 55 */
+
+/* $Log$
+ * Revision 1.15 2004/06/26 03:50:14 markster
+ * Merge source cleanups (bug #1911)
+ *
+ * Revision 1.14 2003/02/12 13:59:15 matteo
+ * mer feb 12 14:56:57 CET 2003
+ *
+ * Revision 1.1.1.1 2003/02/12 13:59:15 matteo
+ * mer feb 12 14:56:57 CET 2003
+ *
+ * Revision 1.2 2000/01/05 08:20:39 markster
+ * Some OSS fixes and a few lpc changes to make it actually work
+ *
+ * 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
+ * */
+/* Revision 1.6 1996/03/15 16:45:25 jaf */
+/* Rearranged a few comments. */
+
+/* Revision 1.5 1996/03/14 23:20:54 jaf */
+/* Added comments about when INITHP100 should be used. */
+
+/* Revision 1.4 1996/03/14 23:08:08 jaf */
+/* Added an entry named INITHP100 that initializes the local state of */
+/* subroutine HP100. */
+
+/* Revision 1.3 1996/03/14 22:09:20 jaf */
+/* Comments added explaining which of the local variables of this */
+/* subroutine need to be saved from one invocation to the next, and which */
+/* do not. */
+
+/* Revision 1.2 1996/02/12 15:05:54 jaf */
+/* Added lots of comments explaining why I changed one line, which was a */
+/* declaration with initializations. */
+
+/* Revision 1.1 1996/02/07 14:47:12 jaf */
+/* Initial revision */
+
+
+/* ********************************************************************* */
+
+/* 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_ */