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Diffstat (limited to 'trunk/codecs/lpc10/deemp.c')
-rw-r--r-- | trunk/codecs/lpc10/deemp.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/trunk/codecs/lpc10/deemp.c b/trunk/codecs/lpc10/deemp.c new file mode 100644 index 000000000..c3b5909ff --- /dev/null +++ b/trunk/codecs/lpc10/deemp.c @@ -0,0 +1,154 @@ +/* + +$Log$ +Revision 1.15 2004/06/26 03:50:14 markster +Merge source cleanups (bug #1911) + +Revision 1.14 2003/02/12 13:59:14 matteo +mer feb 12 14:56:57 CET 2003 + +Revision 1.1.1.1 2003/02/12 13:59:14 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 20:23:46 jaf + * Removed all static local variables that were SAVE'd in the Fortran + * code, and put them in struct lpc10_decoder_state that is passed as an + * argument. + * + * Removed init function, since all initialization is now done in + * init_lpc10_decoder_state(). + * + * Revision 1.1 1996/08/19 22:32:34 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 deemp_(real *x, integer *n, struct lpc10_decoder_state *st); +#endif + +/* ***************************************************************** */ + +/* DEEMP Version 48 */ + +/* $Log$ + * Revision 1.15 2004/06/26 03:50:14 markster + * Merge source cleanups (bug #1911) + * + * Revision 1.14 2003/02/12 13:59:14 matteo + * mer feb 12 14:56:57 CET 2003 + * + * Revision 1.1.1.1 2003/02/12 13:59:14 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 20:23:46 jaf + * Removed all static local variables that were SAVE'd in the Fortran + * code, and put them in struct lpc10_decoder_state that is passed as an + * argument. + * + * Removed init function, since all initialization is now done in + * init_lpc10_decoder_state(). + * + * Revision 1.1 1996/08/19 22:32:34 jaf + * Initial revision + * */ +/* Revision 1.3 1996/03/20 15:54:37 jaf */ +/* Added comments about which indices of array arguments are read or */ +/* written. */ + +/* Added entry INITDEEMP to reinitialize the local state variables, if */ +/* desired. */ + +/* Revision 1.2 1996/03/14 22:11:13 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 1.1 1996/02/07 14:44:53 jaf */ +/* Initial revision */ + + +/* ***************************************************************** */ + +/* De-Emphasize output speech with 1 / ( 1 - .75z**-1 ) */ +/* cascaded with 200 Hz high pass filter */ +/* ( 1 - 1.9998z**-1 + z**-2 ) / ( 1 - 1.75z**-1 + .78z**-2 ) */ + +/* WARNING! The coefficients above may be out of date with the code */ +/* below. Either that, or some kind of transformation was performed */ +/* on the coefficients above to create the code below. */ + +/* Input: */ +/* N - Number of samples */ +/* Input/Output: */ +/* X - Speech */ +/* Indices 1 through N are read before being written. */ + +/* 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 */ +/* INITDEEMP. */ + +/* Subroutine */ int deemp_(real *x, integer *n, struct lpc10_decoder_state *st) +{ + /* Initialized data */ + + real *dei1; + real *dei2; + real *deo1; + real *deo2; + real *deo3; + + /* System generated locals */ + integer i__1; + real r__1; + + /* Local variables */ + integer k; + real dei0; + +/* Arguments */ +/* Local variables that need not be saved */ +/* Local state */ +/* All of the locals saved below were not given explicit initial */ +/* values in the original code. I think 0 is a safe choice. */ + /* Parameter adjustments */ + if (x) { + --x; + } + + /* Function Body */ + + dei1 = &(st->dei1); + dei2 = &(st->dei2); + deo1 = &(st->deo1); + deo2 = &(st->deo2); + deo3 = &(st->deo3); + + i__1 = *n; + for (k = 1; k <= i__1; ++k) { + dei0 = x[k]; + r__1 = x[k] - *dei1 * 1.9998f + *dei2; + x[k] = r__1 + *deo1 * 2.5f - *deo2 * 2.0925f + *deo3 * .585f; + *dei2 = *dei1; + *dei1 = dei0; + *deo3 = *deo2; + *deo2 = *deo1; + *deo1 = x[k]; + } + return 0; +} /* deemp_ */ |