ref: c6e78c58c8ce634b69f979327113e45a805fdaae
dir: /lpc10/encode.c/
/* * Revision 1.1 1996/08/19 22:32:21 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 encode_(integer *voice, integer *pitch, real *rms, real *rc, integer *ipitch, integer *irms, integer *irc); /* Common Block Declarations */ extern struct { integer order, lframe; logical corrp; } contrl_; #define contrl_1 contrl_ /* Table of constant values */ static integer c__2 = 2; /* ***************************************************************** */ /* ENCODE Version 54 */ /* * Revision 1.1 1996/08/19 22:32:21 jaf * Initial revision * */ /* Revision 1.5 1996/03/26 19:35:50 jaf */ /* Commented out trace statements. */ /* Revision 1.4 1996/03/21 00:26:29 jaf */ /* Added the comment that this subroutine has no local state. */ /* In the last check-in, I forgot to mention that I had added comments */ /* explaining which indices of array arguments are read or written. */ /* Revision 1.3 1996/03/21 00:22:39 jaf */ /* Added comments explaining that all local arrays are effectively */ /* constants. */ /* Revision 1.2 1996/03/13 18:48:33 jaf */ /* Comments added explaining that none of the local variables of this */ /* subroutine need to be saved from one invocation to the next. */ /* Revision 1.1 1996/02/07 14:45:29 jaf */ /* Initial revision */ /* ***************************************************************** */ /* Quantize LPC parameters for transmission */ /* INPUTS: */ /* VOICE - Half frame voicing decisions */ /* Indices 1 through 2 read. */ /* PITCH - Pitch */ /* RMS - Energy */ /* RC - Reflection coefficients */ /* Indices 1 through ORDER read. */ /* CORRP - Error Correction: TRUE = yes, FALSE = none */ /* (this is defined in file control.fh) */ /* OUTPUTS: */ /* IPITCH - Coded pitch and voicing */ /* IRMS - Quantized energy */ /* IRC - Quantized reflection coefficients */ /* Indices 1 through MAX(ORDER,2) written. */ /* If CORRP is .TRUE., then indices 1 through 10 written */ /* for unvoiced frames. */ /* This subroutine has no local state. */ /* Subroutine */ int encode_(integer *voice, integer *pitch, real *rms, real * rc, integer *ipitch, integer *irms, integer *irc) { /* 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; /* 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 */ /* 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 = *rms; i__1 = contrl_1.order; for (i__ = 1; i__ <= i__1; ++i__) { irc[i__] = 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 = (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_ */