encode.c File Reference

#include "f2c.h"

Include dependency graph for encode.c:

Go to the source code of this file.

Macros
#define	contrl_1   contrl_

Functions
int	encode_ (integer *voice, integer *pitch, real *rms, real *rc, integer *ipitch, integer *irms, integer *irc)

Variables
static integer	c__2 = 2
struct {
logical   corrp
integer   lframe
integer   order
}	contrl_

Macro Definition Documentation

contrl_1

#define contrl_1   contrl_

Definition at line 41 of file encode.c.

Referenced by encode_().

Function Documentation

encode_()

int encode_	(	integer *	voice,
		integer *	pitch,
		real *	rms,
		real *	rc,
		integer *	ipitch,
		integer *	irms,
		integer *	irc
	)

Definition at line 111 of file encode.c.

References c__2, contrl_1, max, min, and pow_ii().

Referenced by lpc10_encode().

{
    /* Initialized data */

    static integer enctab[16] = { 0,7,11,12,13,10,6,1,14,9,5,2,3,4,8,15 };
    static integer entau[60] = { 19,11,27,25,29,21,23,22,30,14,15,7,39,38,46,
       42,43,41,45,37,53,49,51,50,54,52,60,56,58,26,90,88,92,84,86,82,83,
       81,85,69,77,73,75,74,78,70,71,67,99,97,113,112,114,98,106,104,108,
       100,101,76 };
    static integer enadd[8] = { 1920,-768,2432,1280,3584,1536,2816,-1152 };
    static real enscl[8] = { .0204f,.0167f,.0145f,.0147f,.0143f,.0135f,.0125f,
       .0112f };
    static integer enbits[8] = { 6,5,4,4,4,4,3,3 };
    static integer entab6[64] = { 0,0,0,0,0,0,1,1,1,1,1,1,1,2,2,2,2,2,2,2,3,3,
       3,3,3,3,3,4,4,4,4,4,4,4,5,5,5,5,5,6,6,6,6,6,7,7,7,7,7,8,8,8,8,9,9,
       9,10,10,11,11,12,13,14,15 };
    static integer rmst[64] = { 1024,936,856,784,718,656,600,550,502,460,420,
       384,352,328,294,270,246,226,206,188,172,158,144,132,120,110,102,
       92,84,78,70,64,60,54,50,46,42,38,34,32,30,26,24,22,20,18,17,16,15,
       14,13,12,11,10,9,8,7,6,5,4,3,2,1,0 };

    /* System generated locals */
    integer i__1, i__2;

    /* Builtin functions */
    integer pow_ii(integer *, integer *);

    /* Local variables */
    integer idel, nbit, i__, j, i2, i3, mrk;

/* $Log$
 * Revision 1.15  2004/06/26 03:50:14  markster
 * Merge source cleanups (bug #1911)
 *
 * Revision 1.14  2003/02/12 13:59:15  matteo
 * mer feb 12 14:56:57 CET 2003
 *
 * Revision 1.1.1.1  2003/02/12 13:59:15  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 1.1  1996/08/19  22:32:21  jaf
 * Initial revision
 * */
/* Revision 1.3  1996/03/29  22:03:47  jaf */
/* Removed definitions for any constants that were no longer used. */

/* Revision 1.2  1996/03/26  19:34:33  jaf */
/* Added comments indicating which constants are not needed in an */
/* application that uses the LPC-10 coder. */

/* Revision 1.1  1996/02/07  14:43:51  jaf */
/* Initial revision */

/*   LPC Configuration parameters: */
/* Frame size, Prediction order, Pitch period */
/*       Arguments */
/* $Log$
 * Revision 1.15  2004/06/26 03:50:14  markster
 * Merge source cleanups (bug #1911)
 *
 * Revision 1.14  2003/02/12 13:59:15  matteo
 * mer feb 12 14:56:57 CET 2003
 *
 * Revision 1.1.1.1  2003/02/12 13:59:15  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 1.1  1996/08/19  22:32:21  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 */
/* 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 */
/*       Parameters/constants */
/*       These arrays are not Fortran PARAMETER's, but they are defined */
/*       by DATA statements below, and their contents are never altered.
*/
/*       Local variables that need not be saved */
    /* Parameter adjustments */
    --irc;
    --rc;
    --voice;

    /* Function Body */
/*  Scale RMS and RC's to integers */
    *irms = (integer)*rms;
    i__1 = contrl_1.order;
    for (i__ = 1; i__ <= i__1; ++i__) {
   irc[i__] = (integer)(rc[i__] * 32768.f);
    }
/*    IF(LISTL.GE.3)WRITE(FDEBUG,800)VOICE,PITCH,IRMS,(IRC(I),I=1,ORDER) */
/* 800   FORMAT(1X,/,' <<ENCODE IN>>',T32,2I3,I6,I5,T50,10I8) */
/*  Encode pitch and voicing */
    if (voice[1] != 0 && voice[2] != 0) {
   *ipitch = entau[*pitch - 1];
    } else {
   if (contrl_1.corrp) {
       *ipitch = 0;
       if (voice[1] != voice[2]) {
      *ipitch = 127;
       }
   } else {
       *ipitch = (voice[1] << 1) + voice[2];
   }
    }
/*  Encode RMS by binary table search */
    j = 32;
    idel = 16;
    *irms = min(*irms,1023);
    while(idel > 0) {
   if (*irms > rmst[j - 1]) {
       j -= idel;
   }
   if (*irms < rmst[j - 1]) {
       j += idel;
   }
   idel /= 2;
    }
    if (*irms > rmst[j - 1]) {
   --j;
    }
    *irms = 31 - j / 2;
/*  Encode RC(1) and (2) as log-area-ratios */
    for (i__ = 1; i__ <= 2; ++i__) {
   i2 = irc[i__];
   mrk = 0;
   if (i2 < 0) {
       i2 = -i2;
       mrk = 1;
   }
   i2 /= 512;
   i2 = min(i2,63);
   i2 = entab6[i2];
   if (mrk != 0) {
       i2 = -i2;
   }
   irc[i__] = i2;
    }
/*  Encode RC(3) - (10) linearly, remove bias then scale */
    i__1 = contrl_1.order;
    for (i__ = 3; i__ <= i__1; ++i__) {
   i2 = irc[i__] / 2;
   i2 = (integer)((i2 + enadd[contrl_1.order + 1 - i__ - 1]) * enscl[
      contrl_1.order + 1 - i__ - 1]);
/* Computing MIN */
   i__2 = max(i2,-127);
   i2 = min(i__2,127);
   nbit = enbits[contrl_1.order + 1 - i__ - 1];
   i3 = 0;
   if (i2 < 0) {
       i3 = -1;
   }
   i2 /= pow_ii(&c__2, &nbit);
   if (i3 == -1) {
       --i2;
   }
   irc[i__] = i2;
    }
/*          Protect the most significant bits of the most */
/*     important parameters during non-voiced frames. */
/*     RC(1) - RC(4) are protected using 20 parity bits */
/*     replacing RC(5) - RC(10). */
    if (contrl_1.corrp) {
   if (*ipitch == 0 || *ipitch == 127) {
       irc[5] = enctab[(irc[1] & 30) / 2];
       irc[6] = enctab[(irc[2] & 30) / 2];
       irc[7] = enctab[(irc[3] & 30) / 2];
       irc[8] = enctab[(*irms & 30) / 2];
       irc[9] = enctab[(irc[4] & 30) / 2] / 2;
       irc[10] = enctab[(irc[4] & 30) / 2] & 1;
   }
    }
/*    IF(LISTL.GE.3)WRITE(FDEBUG,801)VOICE,IPITCH,IRMS,(IRC(J),J=1,ORDER) */
/* 801   FORMAT(1X,'<<ENCODE OUT>>',T32,2I3,I6,I5,T50,10I8) */
    return 0;
} /* encode_ */

Variable Documentation

c__2

integer c__2 = 2

static

Definition at line 45 of file encode.c.

Referenced by encode_().

contrl_

struct { ... } contrl_

corrp

logical corrp

Definition at line 38 of file encode.c.

lframe

integer lframe

Definition at line 37 of file encode.c.

order

integer order

Definition at line 37 of file encode.c.