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author | markster <markster@f38db490-d61c-443f-a65b-d21fe96a405b> | 2000-01-05 08:20:27 +0000 |
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committer | markster <markster@f38db490-d61c-443f-a65b-d21fe96a405b> | 2000-01-05 08:20:27 +0000 |
commit | 758d7ac6f9c4db1450b46c6efd2f98280e193ca8 (patch) | |
tree | 2fbfe62756299e2a74e810a68d049ad0c39aa93b /codecs/lpc10/hp100.c | |
parent | cdf6951894d16b31021b98a0a6d3b950ea61b55f (diff) |
Version 0.1.2 from FTP
git-svn-id: http://svn.digium.com/svn/asterisk/trunk@169 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'codecs/lpc10/hp100.c')
-rwxr-xr-x | codecs/lpc10/hp100.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/codecs/lpc10/hp100.c b/codecs/lpc10/hp100.c new file mode 100755 index 000000000..da3ecfb36 --- /dev/null +++ b/codecs/lpc10/hp100.c @@ -0,0 +1,157 @@ +/* + +$Log$ +Revision 1.1 2000/01/05 08:20:39 markster +Version 0.1.2 from FTP + +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 + * + +*/ + +#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 + +/* -- translated by f2c (version 19951025). + You must link the resulting object file with the libraries: + -lf2c -lm (in that order) +*/ + +#include "f2c.h" + +/* ********************************************************************* */ + +/* HP100 Version 55 */ + +/* $Log$ + * Revision 1.1 2000/01/05 08:20:39 markster + * Version 0.1.2 from FTP + * +/* 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_ */ |