ref: ccd23600442db062401526a667332ce4a5b371d5
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_ */