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git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@125 d0543943-73ff-0310-b7d9-9358b9ac24b2
This commit is contained in:
Michael Jerris
169
libs/codec/lpc10/hp100.c
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169
libs/codec/lpc10/hp100.c
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/*
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$Log$
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Revision 1.15 2004/06/26 03:50:14 markster
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Merge source cleanups (bug #1911)
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Revision 1.14 2003/02/12 13:59:15 matteo
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mer feb 12 14:56:57 CET 2003
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Revision 1.1.1.1 2003/02/12 13:59:15 matteo
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mer feb 12 14:56:57 CET 2003
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Revision 1.2 2000/01/05 08:20:39 markster
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Some OSS fixes and a few lpc changes to make it actually work
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* Revision 1.2 1996/08/20 20:28:05 jaf
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* Removed all static local variables that were SAVE'd in the Fortran
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* code, and put them in struct lpc10_encoder_state that is passed as an
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* argument.
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*
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* Removed init function, since all initialization is now done in
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* init_lpc10_encoder_state().
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*
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* Revision 1.1 1996/08/19 22:32:04 jaf
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* Initial revision
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*
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*/
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/* -- translated by f2c (version 19951025).
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You must link the resulting object file with the libraries:
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-lf2c -lm (in that order)
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*/
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#include "f2c.h"
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#ifdef P_R_O_T_O_T_Y_P_E_S
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extern int hp100_(real *speech, integer *start, integer *end,
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struct lpc10_encoder_state *st);
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extern int inithp100_(void);
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#endif
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/* ********************************************************************* */
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/* HP100 Version 55 */
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/* $Log$
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* Revision 1.15 2004/06/26 03:50:14 markster
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* Merge source cleanups (bug #1911)
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*
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/* Revision 1.14 2003/02/12 13:59:15 matteo
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/* mer feb 12 14:56:57 CET 2003
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/*
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/* Revision 1.1.1.1 2003/02/12 13:59:15 matteo
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/* mer feb 12 14:56:57 CET 2003
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/*
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/* Revision 1.2 2000/01/05 08:20:39 markster
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/* Some OSS fixes and a few lpc changes to make it actually work
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/*
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* Revision 1.2 1996/08/20 20:28:05 jaf
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* Removed all static local variables that were SAVE'd in the Fortran
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* code, and put them in struct lpc10_encoder_state that is passed as an
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* argument.
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*
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* Removed init function, since all initialization is now done in
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* init_lpc10_encoder_state().
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*
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* Revision 1.1 1996/08/19 22:32:04 jaf
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* Initial revision
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* */
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/* Revision 1.6 1996/03/15 16:45:25 jaf */
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/* Rearranged a few comments. */
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/* Revision 1.5 1996/03/14 23:20:54 jaf */
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/* Added comments about when INITHP100 should be used. */
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/* Revision 1.4 1996/03/14 23:08:08 jaf */
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/* Added an entry named INITHP100 that initializes the local state of */
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/* subroutine HP100. */
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/* Revision 1.3 1996/03/14 22:09:20 jaf */
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/* Comments added explaining which of the local variables of this */
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/* subroutine need to be saved from one invocation to the next, and which */
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/* do not. */
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/* Revision 1.2 1996/02/12 15:05:54 jaf */
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/* Added lots of comments explaining why I changed one line, which was a */
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/* declaration with initializations. */
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/* Revision 1.1 1996/02/07 14:47:12 jaf */
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/* Initial revision */
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/* ********************************************************************* */
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/* 100 Hz High Pass Filter */
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/* Jan 92 - corrected typo (1.937148 to 1.935715), */
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/* rounded coefficients to 7 places, */
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/* corrected and merged gain (.97466**4), */
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/* merged numerator into first two sections. */
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/* Input: */
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/* start, end - Range of samples to filter */
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/* Input/Output: */
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/* speech(end) - Speech data. */
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/* Indices start through end are read and modified. */
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/* This subroutine maintains local state from one call to the next. If */
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/* you want to switch to using a new audio stream for this filter, or */
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/* reinitialize its state for any other reason, call the ENTRY */
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/* INITHP100. */
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/* Subroutine */ int hp100_(real *speech, integer *start, integer *end,
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struct lpc10_encoder_state *st)
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{
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/* Temporary local copies of variables in lpc10_encoder_state.
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I've only created these because it might cause the loop below
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to execute a bit faster to access local variables, rather than
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variables in the lpc10_encoder_state structure. It is just a
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guess that it will be faster. */
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real z11;
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real z21;
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real z12;
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real z22;
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/* System generated locals */
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integer i__1;
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/* Local variables */
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integer i__;
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real si, err;
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/* Arguments */
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/* Local variables that need not be saved */
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/* Local state */
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/* Parameter adjustments */
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if (speech) {
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--speech;
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}
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/* Function Body */
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z11 = st->z11;
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z21 = st->z21;
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z12 = st->z12;
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z22 = st->z22;
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i__1 = *end;
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for (i__ = *start; i__ <= i__1; ++i__) {
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si = speech[i__];
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err = si + z11 * 1.859076f - z21 * .8648249f;
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si = err - z11 * 2.f + z21;
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z21 = z11;
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z11 = err;
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err = si + z12 * 1.935715f - z22 * .9417004f;
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si = err - z12 * 2.f + z22;
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z22 = z12;
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z12 = err;
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speech[i__] = si * .902428f;
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}
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st->z11 = z11;
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st->z21 = z21;
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st->z12 = z12;
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st->z22 = z22;
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return 0;
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} /* hp100_ */
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