ref: 8f56b0d4535e9b6d46fb22f5b52e26b25e8d46a2
dir: /lpc10/decode.c/
/*
* Revision 1.2 1996/08/20 20:22:39 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 22:32:38 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"
extern int decode_(integer *ipitv, integer *irms, integer *irc, integer *voice, integer *pitch, real *rms, real *rc, struct lpc10_decoder_state *st);
/* Common Block Declarations */
extern struct {
integer order, lframe;
logical corrp;
} contrl_;
#define contrl_1 contrl_
/* Table of constant values */
static integer c__2 = 2;
/* ***************************************************************** */
/* DECODE Version 54 */
/*
* Revision 1.2 1996/08/20 20:22:39 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 22:32:38 jaf
* Initial revision
* */
/* Revision 1.5 1996/05/23 20:06:03 jaf */
/* Assigned PITCH a "default" value on the first call, since otherwise it */
/* would be left uninitialized. */
/* Revision 1.4 1996/03/26 19:35:18 jaf */
/* Commented out trace statements. */
/* Revision 1.3 1996/03/21 21:10:50 jaf */
/* Added entry INITDECODE to reinitialize the local state of subroutine */
/* DECODE. */
/* Revision 1.2 1996/03/21 21:04:50 jaf */
/* Determined which local variables should be saved from one invocation */
/* to the next, and guessed initial values for some that should have been */
/* saved, but weren't given initial values. Many of the arrays are */
/* "constants", and many local variables are only used if the "global" */
/* variable CORRP is .TRUE. */
/* Added comments explaining which indices of array arguments are read or */
/* written. */
/* Revision 1.1 1996/02/12 03:21:10 jaf */
/* Initial revision */
/* ***************************************************************** */
/* This subroutine provides error correction and decoding */
/* for all LPC parameters */
/* Input: */
/* IPITV - Index value of pitch */
/* IRMS - Coded Energy */
/* CORRP - Error correction: */
/* If FALSE, parameters are decoded directly with no delay. If TRUE, */
/* most important parameter bits are protected by Hamming code and */
/* median smoothed. This requires an additional frame of delay. */
/* Input/Output: */
/* IRC - Coded Reflection Coefficients */
/* Indices 1 through ORDER always read, then written. */
/* Output: */
/* VOICE - Half frame voicing decisions */
/* Indices 1 through 2 written. */
/* PITCH - Decoded pitch */
/* RMS - Energy */
/* RC - Reflection coefficients */
/* Indices 1 through ORDER written. */
/* NOTE: Zero RC's should be done more directly, but this would affect */
/* coded parameter printout. */
/* 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 */
/* INITDECODE. */
/* Subroutine */ int decode_(integer *ipitv, integer *irms,
integer *irc, integer *voice, integer *pitch, real *rms, real *rc,
struct lpc10_decoder_state *st)
{
/* Initialized data */
logical *first;
static integer ethrs = 2048;
static integer ethrs1 = 128;
static integer ethrs2 = 1024;
static integer ethrs3 = 2048;
static integer ivtab[32] = { 24960,24960,24960,24960,25480,25480,25483,
25480,16640,1560,1560,1560,16640,1816,1563,1560,24960,24960,24859,
24856,26001,25881,25915,25913,1560,1560,7800,3640,1561,1561,3643,
3641 };
static real corth[32] /* was [4][8] */ = { 32767.f,10.f,5.f,0.f,
32767.f,8.f,4.f,0.f,32.f,6.4f,3.2f,0.f,32.f,6.4f,3.2f,0.f,32.f,
11.2f,6.4f,0.f,32.f,11.2f,6.4f,0.f,16.f,5.6f,3.2f,0.f,16.f,5.6f,
3.2f,0.f };
static integer detau[128] = { 0,0,0,3,0,3,3,31,0,3,3,21,3,3,29,30,0,3,3,
20,3,25,27,26,3,23,58,22,3,24,28,3,0,3,3,3,3,39,33,32,3,37,35,36,
3,38,34,3,3,42,46,44,50,40,48,3,54,3,56,3,52,3,3,1,0,3,3,108,3,78,
100,104,3,84,92,88,156,80,96,3,3,74,70,72,66,76,68,3,62,3,60,3,64,
3,3,1,3,116,132,112,148,152,3,3,140,3,136,3,144,3,3,1,124,120,128,
3,3,3,3,1,3,3,3,1,3,1,1,1 };
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 };
static integer detab7[32] = { 4,11,18,25,32,39,46,53,60,66,72,77,82,87,92,
96,101,104,108,111,114,115,117,119,121,122,123,124,125,126,127,
127 };
static real descl[8] = { .6953f,.625f,.5781f,.5469f,.5312f,.5391f,.4688f,
.3828f };
integer *ivp2h;
static integer deadd[8] = { 1152,-2816,-1536,-3584,-1280,-2432,768,-1920 }
;
static integer qb[8] = { 511,511,1023,1023,1023,1023,2047,4095 };
static integer nbit[10] = { 8,8,5,5,4,4,4,4,3,2 };
static integer zrc[10] = { 0,0,0,0,0,3,0,2,0,0 };
static integer bit[5] = { 2,4,8,16,32 };
integer *iovoic;
integer *iavgp;
integer *iptold;
integer *erate;
integer *drc;
integer *dpit;
integer *drms;
/* System generated locals */
integer i__1, i__2;
/* Builtin functions */
integer pow_ii(integer *, integer *);
/* Local variables */
extern /* Subroutine */ int ham84_(integer *, integer *, integer *);
integer ipit, iout, i__, icorf, index, ivoic, ixcor, i1, i2, i4;
extern integer median_(integer *, integer *, integer *);
integer ishift, errcnt, lsb;
/* LPC Configuration parameters: */
/* Frame size, Prediction order, Pitch period */
/* Arguments */
/* 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 */
/* The variables below that are not Fortran PARAMETER's are */
/* initialized with DATA statements, and then never modified. */
/* The following are used regardless of CORRP's value. */
/* DETAU, NBIT, QB, DEADD, DETAB7, RMST, DESCL */
/* The following are used only if CORRP is .TRUE. */
/* ETHRS, ETHRS1, ETHRS2, ETHRS3, IVTAB, BIT, CORTH, ZRC */
/* Local variables that need not be saved */
/* The following are used regardless of CORRP's value */
/* The following are used only if CORRP is .TRUE. */
/* Local state */
/* The following are used regardless of CORRP's value */
/* The following are used only if CORRP is .TRUE. */
/* I am guessing the initial values for IVP2H, IOVOIC, DRC, DPIT, */
/* and DRMS. They should be checked to see if they are reasonable.
*/
/* I'm also guessing for ERATE, but I think 0 is the right initial
*/
/* value. */
/* Parameter adjustments */
if (irc) {
--irc;
}
if (voice) {
--voice;
}
if (rc) {
--rc;
}
/* Function Body */
iptold = &(st->iptold);
first = &(st->first);
ivp2h = &(st->ivp2h);
iovoic = &(st->iovoic);
iavgp = &(st->iavgp);
erate = &(st->erate);
drc = &(st->drc[0]);
dpit = &(st->dpit[0]);
drms = &(st->drms[0]);
/* DATA statements for "constants" defined above. */
/* IF (LISTL.GE.3) WRITE(FDEBUG,800) IPITV,IRMS,(IRC(J),J=1,ORDER) */
/* 800 FORMAT(1X,' <<ERRCOR IN>>',T32,6X,I6,I5,T50,10I8) */
/* If no error correction, do pitch and voicing then jump to decode */
i4 = detau[*ipitv];
if (! contrl_1.corrp) {
voice[1] = 1;
voice[2] = 1;
if (*ipitv <= 1) {
voice[1] = 0;
}
if (*ipitv == 0 || *ipitv == 2) {
voice[2] = 0;
}
*pitch = i4;
if (*pitch <= 4) {
*pitch = *iptold;
}
if (voice[1] == 1 && voice[2] == 1) {
*iptold = *pitch;
}
if (voice[1] != voice[2]) {
*pitch = *iptold;
}
goto L900;
}
/* Do error correction pitch and voicing */
if (i4 > 4) {
dpit[0] = i4;
ivoic = 2;
*iavgp = (*iavgp * 15 + i4 + 8) / 16;
} else {
ivoic = i4;
dpit[0] = *iavgp;
}
drms[0] = *irms;
i__1 = contrl_1.order;
for (i__ = 1; i__ <= i__1; ++i__) {
drc[i__ * 3 - 3] = irc[i__];
}
/* Determine index to IVTAB from V/UV decision */
/* If error rate is high then use alternate table */
index = (*ivp2h << 4) + (*iovoic << 2) + ivoic + 1;
i1 = ivtab[index - 1];
ipit = i1 & 3;
icorf = i1 / 8;
if (*erate < ethrs) {
icorf /= 64;
}
/* Determine error rate: 4=high 1=low */
ixcor = 4;
if (*erate < ethrs3) {
ixcor = 3;
}
if (*erate < ethrs2) {
ixcor = 2;
}
if (*erate < ethrs1) {
ixcor = 1;
}
/* Voice/unvoice decision determined from bits 0 and 1 of IVTAB */
voice[1] = icorf / 2 & 1;
voice[2] = icorf & 1;
/* Skip decoding on first frame because present data not yet available */
if (*first) {
*first = FALSE_;
/* Assign PITCH a "default" value on the first call, since */
/* otherwise it would be left uninitialized. The two lines
*/
/* below were copied from above, since it seemed like a */
/* reasonable thing to do for the first call. */
*pitch = i4;
if (*pitch <= 4) {
*pitch = *iptold;
}
goto L500;
}
/* If bit 4 of ICORF is set then correct RMS and RC(1) - RC(4). */
/* Determine error rate and correct errors using a Hamming 8,4 code */
/* during transition or unvoiced frame. If IOUT is negative, */
/* more than 1 error occurred, use previous frame's parameters. */
if ((icorf & bit[3]) != 0) {
errcnt = 0;
lsb = drms[1] & 1;
index = (drc[22] << 4) + drms[1] / 2;
ham84_(&index, &iout, &errcnt);
drms[1] = drms[2];
if (iout >= 0) {
drms[1] = (iout << 1) + lsb;
}
for (i__ = 1; i__ <= 4; ++i__) {
if (i__ == 1) {
i1 = ((drc[25] & 7) << 1) + (drc[28] & 1);
} else {
i1 = drc[(9 - i__) * 3 - 2] & 15;
}
i2 = drc[(5 - i__) * 3 - 2] & 31;
lsb = i2 & 1;
index = (i1 << 4) + i2 / 2;
ham84_(&index, &iout, &errcnt);
if (iout >= 0) {
iout = (iout << 1) + lsb;
if ((iout & 16) == 16) {
iout += -32;
}
} else {
iout = drc[(5 - i__) * 3 - 1];
}
drc[(5 - i__) * 3 - 2] = iout;
}
/* Determine error rate */
*erate = *erate * .96875f + errcnt * 102;
}
/* Get unsmoothed RMS, RC's, and PITCH */
*irms = drms[1];
i__1 = contrl_1.order;
for (i__ = 1; i__ <= i__1; ++i__) {
irc[i__] = drc[i__ * 3 - 2];
}
if (ipit == 1) {
dpit[1] = dpit[2];
}
if (ipit == 3) {
dpit[1] = dpit[0];
}
*pitch = dpit[1];
/* If bit 2 of ICORF is set then smooth RMS and RC's, */
if ((icorf & bit[1]) != 0) {
if ((i__1 = drms[1] - drms[0], (real) abs(i__1)) >= corth[ixcor + 3]
&& (i__2 = drms[1] - drms[2], (real) abs(i__2)) >= corth[
ixcor + 3]) {
*irms = median_(&drms[2], &drms[1], drms);
}
for (i__ = 1; i__ <= 6; ++i__) {
if ((i__1 = drc[i__ * 3 - 2] - drc[i__ * 3 - 3], (real) abs(i__1))
>= corth[ixcor + ((i__ + 2) << 2) - 5] && (i__2 = drc[i__ *
3 - 2] - drc[i__ * 3 - 1], (real) abs(i__2)) >= corth[
ixcor + ((i__ + 2) << 2) - 5]) {
irc[i__] = median_(&drc[i__ * 3 - 1], &drc[i__ * 3 - 2], &drc[
i__ * 3 - 3]);
}
}
}
/* If bit 3 of ICORF is set then smooth pitch */
if ((icorf & bit[2]) != 0) {
if ((i__1 = dpit[1] - dpit[0], (real) abs(i__1)) >= corth[ixcor - 1]
&& (i__2 = dpit[1] - dpit[2], (real) abs(i__2)) >= corth[
ixcor - 1]) {
*pitch = median_(&dpit[2], &dpit[1], dpit);
}
}
/* If bit 5 of ICORF is set then RC(5) - RC(10) are loaded with */
/* values so that after quantization bias is removed in decode */
/* the values will be zero. */
L500:
if ((icorf & bit[4]) != 0) {
i__1 = contrl_1.order;
for (i__ = 5; i__ <= i__1; ++i__) {
irc[i__] = zrc[i__ - 1];
}
}
/* House keeping - one frame delay */
*iovoic = ivoic;
*ivp2h = voice[2];
dpit[2] = dpit[1];
dpit[1] = dpit[0];
drms[2] = drms[1];
drms[1] = drms[0];
i__1 = contrl_1.order;
for (i__ = 1; i__ <= i__1; ++i__) {
drc[i__ * 3 - 1] = drc[i__ * 3 - 2];
drc[i__ * 3 - 2] = drc[i__ * 3 - 3];
}
L900:
/* IF (LISTL.GE.3)WRITE(FDEBUG,801)VOICE,PITCH,IRMS,(IRC(J),J=1,ORDER) */
/* 801 FORMAT(1X,'<<ERRCOR OUT>>',T32,2I3,I6,I5,T50,10I8) */
/* Decode RMS */
*irms = rmst[(31 - *irms) * 2];
/* Decode RC(1) and RC(2) from log-area-ratios */
/* Protect from illegal coded value (-16) caused by bit errors */
for (i__ = 1; i__ <= 2; ++i__) {
i2 = irc[i__];
i1 = 0;
if (i2 < 0) {
i1 = 1;
i2 = -i2;
if (i2 > 15) {
i2 = 0;
}
}
i2 = detab7[i2 * 2];
if (i1 == 1) {
i2 = -i2;
}
ishift = 15 - nbit[i__ - 1];
irc[i__] = i2 * pow_ii(&c__2, &ishift);
}
/* Decode RC(3)-RC(10) to sign plus 14 bits */
i__1 = contrl_1.order;
for (i__ = 3; i__ <= i__1; ++i__) {
i2 = irc[i__];
ishift = 15 - nbit[i__ - 1];
i2 *= pow_ii(&c__2, &ishift);
i2 += qb[i__ - 3];
irc[i__] = i2 * descl[i__ - 3] + deadd[i__ - 3];
}
/* IF (LISTL.GE.3) WRITE(FDEBUG,811) IRMS, (IRC(I),I=1,ORDER) */
/* 811 FORMAT(1X,'<<DECODE OUT>>',T45,I4,1X,10I8) */
/* Scale RMS and RC's to reals */
*rms = (real) (*irms);
i__1 = contrl_1.order;
for (i__ = 1; i__ <= i__1; ++i__) {
rc[i__] = irc[i__] / 16384.f;
}
return 0;
} /* decode_ */