ref: 968c689ad2c4269a1a853434d99aa7ebf0c01354
dir: /lpc10/bsynz.c/
/*
* Revision 1.2 1996/08/20 20:18:55 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 22:32:58 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"
int bsynz_(real *coef, integer *ip, integer *iv, real *sout, real *rms, real *ratio, real *g2pass, struct lpc10_decoder_state *st);
/* Common Block Declarations */
extern struct {
integer order, lframe;
logical corrp;
} contrl_;
#define contrl_1 contrl_
/* ***************************************************************** */
/* BSYNZ Version 54 */
/*
* Revision 1.2 1996/08/20 20:18:55 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 22:32:58 jaf
* Initial revision
* */
/* Revision 1.4 1996/03/27 18:11:22 jaf */
/* Changed the range of NOISE printed out in the debugging statements, */
/* even though they are commented out. I didn't discover this until I */
/* tried comparing two different versions of the LPC-10 coder, each with */
/* full tracing enabled. */
/* Revision 1.3 1996/03/26 19:33:23 jaf */
/* Commented out trace statements. */
/* Revision 1.2 1996/03/20 17:12:54 jaf */
/* Added comments about which indices of array arguments are read or */
/* written. */
/* Rearranged local variable declarations to indicate which need to be */
/* saved from one invocation to the next. Added entry INITBSYNZ to */
/* reinitialize the local state variables, if desired. */
/* Revision 1.1 1996/02/07 14:43:15 jaf */
/* Initial revision */
/* ***************************************************************** */
/* Synthesize One Pitch Epoch */
/* Input: */
/* COEF - Predictor coefficients */
/* Indices 1 through ORDER read. */
/* IP - Pitch period (number of samples to synthesize) */
/* IV - Voicing for the current epoch */
/* RMS - Energy for the current epoch */
/* RATIO - Energy slope for plosives */
/* G2PASS- Sharpening factor for 2 pass synthesis */
/* Output: */
/* SOUT - Synthesized speech */
/* Indices 1 through IP 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 */
/* INITBSYNZ. */
/* Subroutine */ int bsynz_(real *coef, integer *ip, integer *iv,
real *sout, real *rms, real *ratio, real *g2pass,
struct lpc10_decoder_state *st)
{
/* Initialized data */
integer *ipo;
real *rmso;
static integer kexc[25] = { 8,-16,26,-48,86,-162,294,-502,718,-728,184,
672,-610,-672,184,728,718,502,294,162,86,48,26,16,8 };
real *exc;
real *exc2;
real *lpi1;
real *lpi2;
real *lpi3;
real *hpi1;
real *hpi2;
real *hpi3;
/* System generated locals */
integer i__1, i__2;
real r__1, r__2;
/* Builtin functions */
double sqrt(doublereal);
/* Local variables */
real gain, xssq;
integer i__, j, k;
real noise[166], pulse;
integer px;
real sscale;
extern integer random_(struct lpc10_decoder_state *);
real xy, sum, ssq;
real lpi0, hpi0;
/* LPC Processing control variables: */
/* *** Read-only: initialized in setup */
/* Files for Speech, Parameter, and Bitstream Input & Output, */
/* and message and debug outputs. */
/* Here are the only files which use these variables: */
/* lpcsim.f setup.f trans.f error.f vqsetup.f */
/* Many files which use fdebug are not listed, since it is only used in */
/* those other files conditionally, to print trace statements. */
/* integer fsi, fso, fpi, fpo, fbi, fbo, pbin, fmsg, fdebug */
/* LPC order, Frame size, Quantization rate, Bits per frame, */
/* Error correction */
/* Subroutine SETUP is the only place where order is assigned a value, */
/* and that value is 10. It could increase efficiency 1% or so to */
/* declare order as a constant (i.e., a Fortran PARAMETER) instead of as
*/
/* a variable in a COMMON block, since it is used in many places in the */
/* core of the coding and decoding routines. Actually, I take that back.
*/
/* At least when compiling with f2c, the upper bound of DO loops is */
/* stored in a local variable before the DO loop begins, and then that is
*/
/* compared against on each iteration. */
/* Similarly for lframe, which is given a value of MAXFRM in SETUP. */
/* Similarly for quant, which is given a value of 2400 in SETUP. quant */
/* is used in only a few places, and never in the core coding and */
/* decoding routines, so it could be eliminated entirely. */
/* nbits is similar to quant, and is given a value of 54 in SETUP. */
/* corrp is given a value of .TRUE. in SETUP, and is only used in the */
/* subroutines ENCODE and DECODE. It doesn't affect the speed of the */
/* coder significantly whether it is .TRUE. or .FALSE., or whether it is
*/
/* a constant or a variable, since it is only examined once per frame. */
/* Leaving it as a variable that is set to .TRUE. seems like a good */
/* idea, since it does enable some error-correction capability for */
/* unvoiced frames, with no change in the coding rate, and no noticeable
*/
/* quality difference in the decoded speech. */
/* integer quant, nbits */
/* *** Read/write: variables for debugging, not needed for LPC algorithm
*/
/* Current frame, Unstable frames, Output clip count, Max onset buffer,
*/
/* Debug listing detail level, Line count on listing page */
/* nframe is not needed for an embedded LPC10 at all. */
/* nunsfm is initialized to 0 in SETUP, and incremented in subroutine */
/* ERROR, which is only called from RCCHK. When LPC10 is embedded into */
/* an application, I would recommend removing the call to ERROR in RCCHK,
*/
/* and remove ERROR and nunsfm completely. */
/* iclip is initialized to 0 in SETUP, and incremented in entry SWRITE in
*/
/* sread.f. When LPC10 is embedded into an application, one might want */
/* to cause it to be incremented in a routine that takes the output of */
/* SYNTHS and sends it to an audio device. It could be optionally */
/* displayed, for those that might want to know what it is. */
/* maxosp is never initialized to 0 in SETUP, although it probably should
*/
/* be, and it is updated in subroutine ANALYS. I doubt that its value */
/* would be of much interest to an application in which LPC10 is */
/* embedded. */
/* listl and lincnt are not needed for an embedded LPC10 at all. */
/* integer nframe, nunsfm, iclip, maxosp, listl, lincnt */
/* common /contrl/ fsi, fso, fpi, fpo, fbi, fbo, pbin, fmsg, fdebug */
/* common /contrl/ quant, nbits */
/* common /contrl/ nframe, nunsfm, iclip, maxosp, listl, lincnt */
/* Function return value definitions */
/* Parameters/constants */
/* KEXC is not a Fortran PARAMETER, but it is an array initialized
*/
/* with a DATA statement that is never modified. */
/* Local variables that need not be saved */
/* NOISE is declared with range (1:MAXPIT+MAXORD), but only indices
*/
/* ORDER+1 through ORDER+IP are ever used, and I think that IP */
/* .LE. MAXPIT. Why not declare it to be in the range (1:MAXPIT) */
/* and use that range? */
/* Local state */
/* I believe that only indices 1 through ORDER of EXC need to be */
/* saved from one invocation to the next, but we may as well save */
/* the whole array. */
/* None of these local variables were given initial values in the */
/* original code. I'm guessing that 0 is a reasonable initial */
/* value for all of them. */
/* Parameter adjustments */
if (coef) {
--coef;
}
if (sout) {
--sout;
}
/* Function Body */
ipo = &(st->ipo);
exc = &(st->exc[0]);
exc2 = &(st->exc2[0]);
lpi1 = &(st->lpi1);
lpi2 = &(st->lpi2);
lpi3 = &(st->lpi3);
hpi1 = &(st->hpi1);
hpi2 = &(st->hpi2);
hpi3 = &(st->hpi3);
rmso = &(st->rmso_bsynz);
/* MAXPIT+MAXORD=166 */
/* Calculate history scale factor XY and scale filter state */
/* Computing MIN */
r__1 = *rmso / (*rms + 1e-6f);
xy = min(r__1,8.f);
*rmso = *rms;
i__1 = contrl_1.order;
for (i__ = 1; i__ <= i__1; ++i__) {
exc2[i__ - 1] = exc2[*ipo + i__ - 1] * xy;
}
*ipo = *ip;
if (*iv == 0) {
/* Generate white noise for unvoiced */
i__1 = *ip;
for (i__ = 1; i__ <= i__1; ++i__) {
exc[contrl_1.order + i__ - 1] = (real) (random_(st) / 64);
}
/* Impulse doublet excitation for plosives */
/* (RANDOM()+32768) is in the range 0 to 2**16-1. Therefore the
*/
/* following expression should be evaluated using integers with
at */
/* least 32 bits (16 isn't enough), and PX should be in the rang
e */
/* ORDER+1+0 through ORDER+1+(IP-2) .EQ. ORDER+IP-1. */
px = (random_(st) + 32768) * (*ip - 1) / 65536 + contrl_1.order + 1;
r__1 = *ratio / 4 * 1.f;
pulse = r__1 * 342;
if (pulse > 2e3f) {
pulse = 2e3f;
}
exc[px - 1] += pulse;
exc[px] -= pulse;
/* Load voiced excitation */
} else {
sscale = sqrt((real) (*ip)) / 6.928f;
i__1 = *ip;
for (i__ = 1; i__ <= i__1; ++i__) {
exc[contrl_1.order + i__ - 1] = 0.f;
if (i__ <= 25) {
exc[contrl_1.order + i__ - 1] = sscale * kexc[i__ - 1];
}
lpi0 = exc[contrl_1.order + i__ - 1];
r__2 = exc[contrl_1.order + i__ - 1] * .125f + *lpi1 * .75f;
r__1 = r__2 + *lpi2 * .125f;
exc[contrl_1.order + i__ - 1] = r__1 + *lpi3 * 0.f;
*lpi3 = *lpi2;
*lpi2 = *lpi1;
*lpi1 = lpi0;
}
i__1 = *ip;
for (i__ = 1; i__ <= i__1; ++i__) {
noise[contrl_1.order + i__ - 1] = random_(st) * 1.f / 64;
hpi0 = noise[contrl_1.order + i__ - 1];
r__2 = noise[contrl_1.order + i__ - 1] * -.125f + *hpi1 * .25f;
r__1 = r__2 + *hpi2 * -.125f;
noise[contrl_1.order + i__ - 1] = r__1 + *hpi3 * 0.f;
*hpi3 = *hpi2;
*hpi2 = *hpi1;
*hpi1 = hpi0;
}
i__1 = *ip;
for (i__ = 1; i__ <= i__1; ++i__) {
exc[contrl_1.order + i__ - 1] += noise[contrl_1.order + i__ - 1];
}
}
/* Synthesis filters: */
/* Modify the excitation with all-zero filter 1 + G*SUM */
xssq = 0.f;
i__1 = *ip;
for (i__ = 1; i__ <= i__1; ++i__) {
k = contrl_1.order + i__;
sum = 0.f;
i__2 = contrl_1.order;
for (j = 1; j <= i__2; ++j) {
sum += coef[j] * exc[k - j - 1];
}
sum *= *g2pass;
exc2[k - 1] = sum + exc[k - 1];
}
/* Synthesize using the all pole filter 1 / (1 - SUM) */
i__1 = *ip;
for (i__ = 1; i__ <= i__1; ++i__) {
k = contrl_1.order + i__;
sum = 0.f;
i__2 = contrl_1.order;
for (j = 1; j <= i__2; ++j) {
sum += coef[j] * exc2[k - j - 1];
}
exc2[k - 1] = sum + exc2[k - 1];
xssq += exc2[k - 1] * exc2[k - 1];
}
/* Save filter history for next epoch */
i__1 = contrl_1.order;
for (i__ = 1; i__ <= i__1; ++i__) {
exc[i__ - 1] = exc[*ip + i__ - 1];
exc2[i__ - 1] = exc2[*ip + i__ - 1];
}
/* Apply gain to match RMS */
r__1 = *rms * *rms;
ssq = r__1 * *ip;
gain = sqrt(ssq / xssq);
i__1 = *ip;
for (i__ = 1; i__ <= i__1; ++i__) {
sout[i__] = gain * exc2[contrl_1.order + i__ - 1];
}
return 0;
} /* bsynz_ */