voicin.c

10阶LPC编解码及源程序

/*

$Log: voicin.c,v $
Revision 1.1.1.1  2001/11/19 19:50:17  smorlat
First cvs.

Revision 1.1.1.1  2001/08/08 21:29:08  simon
First import

 * Revision 1.2  1996/08/20  20:45:00  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  22:30:14  jaf
 * Initial revision
 *

*/

#ifdef P_R_O_T_O_T_Y_P_E_S
extern int voicin_(integer *vwin, real *inbuf, real *lpbuf, integer *buflim, integer *half, real *minamd, real *maxamd, integer *mintau, real *ivrc, integer *obound, integer *voibuf, integer *af, struct lpc10_encoder_state *st);
/* comlen contrl_ 12 */
/*:ref: vparms_ 14 14 4 6 6 4 4 6 4 4 4 4 6 6 6 6 */
#endif

/*  -- translated by f2c (version 19951025).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

/* Common Block Declarations */

extern struct {
    integer order, lframe;
    logical corrp;
} contrl_;

#define contrl_1 contrl_

/****************************************************************************/

/* 	VOICIN Version 52 */

/* $Log: voicin.c,v $
/* Revision 1.1.1.1  2001/11/19 19:50:17  smorlat
/* First cvs.
/*
/* Revision 1.1.1.1  2001/08/08 21:29:08  simon
/* First import
/*
 * Revision 1.2  1996/08/20  20:45:00  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  22:30:14  jaf
 * Initial revision
 * */
/* Revision 1.10  1996/03/29  17:59:14  jaf */
/* Avoided using VALUE(9), although it shouldn't affect the function of */
/* the code at all, because it was always multiplied by VDC(9,SNRL), */
/* which is 0 for all values of SNRL.  Still, if VALUE(9) had an initial */
/* value of IEEE NaN, it might cause trouble (I don't know how IEEE */
/* defines Nan * 0.  It should either be NaN or 0.) */

/* Revision 1.9  1996/03/29  17:54:46  jaf */
/* Added a few comments about the accesses made to argument array VOIBUF */
/* and the local saved array VOICE. */

/* Revision 1.8  1996/03/27  18:19:54  jaf */
/* Added an assignment to VSTATE that does not affect the function of the */
/* program at all.  The only reason I put it in was so that the tracing */
/* statements at the end, when enabled, will print a consistent value for */
/* VSTATE when HALF .EQ. 1, rather than a garbage value that could change */
/* from one call to the next. */

/* Revision 1.7  1996/03/26  20:00:06  jaf */
/* Removed the inclusion of the file "vcomm.fh", and put its contents */
/* into this file.  It was included nowhere else but here. */

/* Revision 1.6  1996/03/26  19:38:09  jaf */
/* Commented out trace statements. */

/* Revision 1.5  1996/03/19  20:43:45  jaf */
/* Added comments about which indices of OBOUND and VOIBUF can be */
/* accessed, and whether they are read or written.  VOIBUF is fairly */
/* messy. */

/* Revision 1.4  1996/03/19  15:00:58  jaf */
/* Moved the DATA statements for the *VDC* variables later, as it is */
/* apparently illegal to have DATA statements before local variable */
/* declarations. */

/* Revision 1.3  1996/03/19  00:10:49  jaf */
/* Heavily commented the local variables that are saved from one */
/* invocation to the next, and how the local variable FIRST is used to */
/* avoid the need to assign most of them initial values with DATA */
/* statements. */

/* A few should be initialized, but aren't.  I've guessed initial values */
/* for two of these, SFBUE and SLBUE, and I've convinced myself that for */
/* VOICE, the effects of uninitialized values will die out after 2 or 3 */
/* frame times.  It would still be good to choose initial values for */
/* these, but I don't know what reasonable values would be (0 comes to */
/* mind). */

/* Revision 1.2  1996/03/13  16:09:28  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. */

/* WARNING!  Some of them that should are never given initial values in */
/* this code.  Hopefully, Fortran 77 defines initial values for them, but */
/* even so, giving them explicit initial values is preferable. */

/* WARNING!  VALUE(9) is used, but never assigned a value.  It should */
/* probably be eliminated from the code. */

/* Revision 1.1  1996/02/07 14:50:28  jaf */
/* Initial revision */


/****************************************************************************/

/*        Voicing Detection (VOICIN) makes voicing decisions for each half */
/*  frame of input speech.  Tentative voicing decisions are made two frames*/
/*   in the future (2F) for each half frame.  These decisions are carried */
/*   through one frame in the future (1F) to the present (P) frame where */
/*   they are examined and smoothed, resulting in the final voicing */
/*   decisions for each half frame. */
/*        The voicing parameter (signal measurement) column vector (VALUE) */
/*   is based on a rectangular window of speech samples determined by the */
/*  window placement algorithm.  The voicing parameter vector contains the*/
/*  AMDF windowed maximum-to-minimum ratio, the zero crossing rate, energy*/
/*   measures, reflection coefficients, and prediction gains.  The voicing */
/*  window is placed to avoid contamination of the voicing parameter vector*/
/*   with speech onsets. */
/*        The input signal is then classified as unvoiced (including */
/*   silence) or voiced.  This decision is made by a linear discriminant */
/*   function consisting of a dot product of the voicing decision */
/*   coefficient (VDC) row vector with the measurement column vector */
/*  (VALUE).  The VDC vector is 2-dimensional, each row vector is optimized*/
/*   for a particular signal-to-noise ratio (SNR).  So, before the dot */
/*   product is performed, the SNR is estimated to select the appropriate */
/*   VDC vector. */
/*        The smoothing algorithm is a modified median smoother.  The */
/*  voicing discriminant function is used by the smoother to determine how*/
/*   strongly voiced or unvoiced a signal is.  The smoothing is further */
/*   modified if a speech onset and a voicing decision transition occur */
/*   within one half frame.  In this case, the voicing decision transition */
/*  is extended to the speech onset.  For transmission purposes, there are*/
/*   constraints on the duration and transition of voicing decisions.  The */
/*   smoother takes these constraints into account. */
/*        Finally, the energy estimates are updated along with the dither */
/*   threshold used to calculate the zero crossing rate (ZC). */

/* Inputs: */
/*  VWIN      - Voicing window limits */
/*              The indices read of arrays VWIN, INBUF, LPBUF, and BUFLIM */
/*              are the same as those read by subroutine VPARMS. */
/*  INBUF     - Input speech buffer */
/*  LPBUF     - Low-pass filtered speech buffer */
/*  BUFLIM    - INBUF and LPBUF limits */
/*  HALF      - Present analysis half frame number */
/*  MINAMD    - Minimum value of the AMDF */
/*  MAXAMD    - Maximum value of the AMDF */
/*  MINTAU    - Pointer to the lag of the minimum AMDF value */
/*  IVRC(2)   - Inverse filter's RC's */
/*              Only index 2 of array IVRC read under normal operation. */
/*              (Index 1 is also read when debugging is turned on.) */
/*  OBOUND    - Onset boundary descriptions */
/*             Indices 1 through 3 read if (HALF .NE. 1), otherwise untouched.
*/
/*  AF        - The analysis frame number */
/* Output: */
/*  VOIBUF(2,0:AF) - Buffer of voicing decisions */
/*              Index (HALF,3) written. */
/*              If (HALF .EQ. 1), skip down to "Read (HALF,3)" below. */
/*              Indices (1,2), (2,1), (1,2), and (2,2) read. */
/*              One of the following is then done: */
/*                 read (1,3) and possibly write (1,2) */
/*                 read (1,3) and write (1,2) or (2,2) */
/*                 write (2,1) */
/*                 write (2,1) or (1,2) */
/*                 read (1,0) and (1,3) and then write (2,2) or (1,1) */
/*                 no reads or writes on VOIBUF */
/*              Finally, read (HALF,3) */
/* Internal: */
/*  QS        - Ratio of preemphasized to full-band energies */
/*  RC1       - First reflection coefficient */
/* AR_B      - Product of the causal forward and reverse pitch prediction gain
s*/
/* AR_F      - Product of the noncausal forward and rev. pitch prediction gain
s*/
/*  ZC        - Zero crossing rate */
/*  DITHER    - Zero crossing threshold level */
/*  MAXMIN    - AMDF's 1 octave windowed maximum-to-minimum ratio */
/*  MINPTR    - Location  of minimum AMDF value */
/*  NVDC      - Number of elements in each VDC vector */
/*  NVDCL     - Number of VDC vectors */
/*  VDCL      - SNR values corresponding to the set of VDC's */
/*  VDC       - 2-D voicing decision coefficient vector */
/*  VALUE(9)  - Voicing Parameters */
/*  VOICE(2,3)- History of LDA results */
/*              On every call when (HALF .EQ. 1), VOICE(*,I+1) is */
/*              shifted back to VOICE(*,I), for I=1,2. */
/*              VOICE(HALF,3) is written on every call. */
/*              Depending on several conditions, one or more of */
/*              (1,1), (1,2), (2,1), and (2,2) might then be read. */
/*  LBE       - Ratio of low-band instantaneous to average energies */
/*  FBE       - Ratio of full-band instantaneous to average energies */
/*  LBVE      - Low band voiced energy */
/*  LBUE      - Low band unvoiced energy */
/*  FBVE      - Full band voiced energy */
/*  FBUE      - Full band unvoiced energy */
/*  OFBUE     - Previous full-band unvoiced energy */
/*  OLBUE     - Previous low-band unvoiced energy */
/*  REF       - Reference energy for initialization and DITHER threshold */
/*  SNR       - Estimate of signal-to-noise ratio */
/*  SNR2      - Estimate of low-band signal-to-noise ratio */
/*  SNRL      - SNR level number */
/*  OT        - Onset transition present */
/*  VSTATE    - Decimal interpretation of binary voicing classifications */
/*  FIRST     - First call flag */

/* 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 */
/* INITVOICIN. */

/* Subroutine */ int voicin_(integer *vwin, real *inbuf, real *
	lpbuf, integer *buflim, integer *half, real *minamd, real *maxamd, 
	integer *mintau, real *ivrc, integer *obound, integer *voibuf, 
	integer *af, struct lpc10_encoder_state *st)
{
    /* Initialized data */

    real *dither;
    static real vdc[100]	/* was [10][10] */ = { 0.f,1714.f,-110.f,
	    334.f,-4096.f,-654.f,3752.f,3769.f,0.f,1181.f,0.f,874.f,-97.f,
	    300.f,-4096.f,-1021.f,2451.f,2527.f,0.f,-500.f,0.f,510.f,-70.f,
	    250.f,-4096.f,-1270.f,2194.f,2491.f,0.f,-1500.f,0.f,500.f,-10.f,
	    200.f,-4096.f,-1300.f,2e3f,2e3f,0.f,-2e3f,0.f,500.f,0.f,0.f,
	    -4096.f,-1300.f,2e3f,2e3f,0.f,-2500.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,
	    0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,
	    0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,
	    0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f,0.f };
    static integer nvdcl = 5;
    static real vdcl[10] = { 600.f,450.f,300.f,200.f,0.f,0.f,0.f,0.f,0.f,0.f }
	    ;

    /* System generated locals */
    integer inbuf_offset, lpbuf_offset, i__1, i__2;
    real r__1, r__2;

    /* Builtin functions */
    integer i_nint(real *);
    double sqrt(doublereal);

    /* Local variables */
    real ar_b__, ar_f__;
    integer *lbve, *lbue, *fbve, *fbue;
    integer snrl, i__;
    integer *ofbue, *sfbue;
    real *voice;
    integer *olbue, *slbue;
    real value[9];
    integer zc;
    logical ot;
    real qs;
    real *maxmin;
    integer vstate;
    real rc1;
    extern /* Subroutine */ int vparms_(integer *, real *, real *, integer *, 
	    integer *, real *, integer *, integer *, integer *, integer *, 
	    real *, real *, real *, real *);
    integer fbe, lbe;
    real *snr;
    real snr2;

/* 	Global Variables: */
/*       Arguments */
/* $Log: voicin.c,v $
/* Revision 1.1.1.1  2001/11/19 19:50:17  smorlat
/* First cvs.
/*
/* Revision 1.1.1.1  2001/08/08 21:29:08  simon
/* First import
/*
 * Revision 1.2  1996/08/20  20:45:00  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  22:30:14  jaf
 * Initial revision
 * */
/* Revision 1.3  1996/03/29  22:05:55  jaf */
/* Commented out the common block variables that are not needed by the */
/* embedded version. */

/* Revision 1.2  1996/03/26  19:34:50  jaf */
/* Added comments indicating which constants are not needed in an */
/* application that uses the LPC-10 coder. */

/* Revision 1.1  1996/02/07  14:44:09  jaf */
/* Initial revision */

/*   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 */