lpc10/encode.c

   1 /*
   2
   3  * Revision 1.1  1996/08/19  22:32:21  jaf
   4  * Initial revision
   5  *
   6
   7 */
   8
   9 /*  -- translated by f2c (version 19951025).
  10    You must link the resulting object file with the libraries:
  11         -lf2c -lm   (in that order)
  12 */
  13
  14 #include "f2c.h"
  15
  16 extern int encode_(integer *voice, integer *pitch, real *rms, real *rc, integer *ipitch, integer *irms, integer *irc);
  17
  18 /* Common Block Declarations */
  19
  20 extern struct {
  21     integer order, lframe;
  22     logical corrp;
  23 } contrl_;
  24
  25 #define contrl_1 contrl_
  26
  27 /* Table of constant values */
  28
  29 static integer c__2 = 2;
  30
  31 /* ***************************************************************** */
  32
  33 /*      ENCODE Version 54 */
  34
  35 /*
  36  * Revision 1.1  1996/08/19  22:32:21  jaf
  37  * Initial revision
  38  * */
  39 /* Revision 1.5  1996/03/26  19:35:50  jaf */
  40 /* Commented out trace statements. */
  41
  42 /* Revision 1.4  1996/03/21  00:26:29  jaf */
  43 /* Added the comment that this subroutine has no local state. */
  44
  45 /* In the last check-in, I forgot to mention that I had added comments */
  46 /* explaining which indices of array arguments are read or written. */
  47
  48 /* Revision 1.3  1996/03/21  00:22:39  jaf */
  49 /* Added comments explaining that all local arrays are effectively */
  50 /* constants. */
  51
  52 /* Revision 1.2  1996/03/13  18:48:33  jaf */
  53 /* Comments added explaining that none of the local variables of this */
  54 /* subroutine need to be saved from one invocation to the next. */
  55
  56 /* Revision 1.1  1996/02/07 14:45:29  jaf */
  57 /* Initial revision */
  58
  59
  60 /* ***************************************************************** */
  61
  62 /*  Quantize LPC parameters for transmission */
  63
  64 /* INPUTS: */
  65 /*  VOICE  - Half frame voicing decisions */
  66 /*           Indices 1 through 2 read. */
  67 /*  PITCH  - Pitch */
  68 /*  RMS    - Energy */
  69 /*  RC     - Reflection coefficients */
  70 /*           Indices 1 through ORDER read. */
  71 /*  CORRP  - Error Correction: TRUE = yes, FALSE = none */
  72 /*           (this is defined in file control.fh) */
  73 /* OUTPUTS: */
  74 /*  IPITCH - Coded pitch and voicing */
  75 /*  IRMS   - Quantized energy */
  76 /*  IRC    - Quantized reflection coefficients */
  77 /*           Indices 1 through MAX(ORDER,2) written. */
  78 /*           If CORRP is .TRUE., then indices 1 through 10 written */
  79 /*           for unvoiced frames. */
  80
  81 /* This subroutine has no local state. */
  82
  83 /* Subroutine */ int encode_(integer *voice, integer *pitch, real *rms, real *
  84         rc, integer *ipitch, integer *irms, integer *irc)
  85 {
  86     /* Initialized data */
  87
  88     static integer enctab[16] = { 0,7,11,12,13,10,6,1,14,9,5,2,3,4,8,15 };
  89     static integer entau[60] = { 19,11,27,25,29,21,23,22,30,14,15,7,39,38,46,
  90             42,43,41,45,37,53,49,51,50,54,52,60,56,58,26,90,88,92,84,86,82,83,
  91             81,85,69,77,73,75,74,78,70,71,67,99,97,113,112,114,98,106,104,108,
  92             100,101,76 };
  93     static integer enadd[8] = { 1920,-768,2432,1280,3584,1536,2816,-1152 };
  94     static real enscl[8] = { .0204f,.0167f,.0145f,.0147f,.0143f,.0135f,.0125f,
  95             .0112f };
  96     static integer enbits[8] = { 6,5,4,4,4,4,3,3 };
  97     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,
  98             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,
  99             9,10,10,11,11,12,13,14,15 };
 100     static integer rmst[64] = { 1024,936,856,784,718,656,600,550,502,460,420,
 101             384,352,328,294,270,246,226,206,188,172,158,144,132,120,110,102,
 102             92,84,78,70,64,60,54,50,46,42,38,34,32,30,26,24,22,20,18,17,16,15,
 103             14,13,12,11,10,9,8,7,6,5,4,3,2,1,0 };
 104
 105     /* System generated locals */
 106     integer i__1, i__2;
 107
 108     /* Builtin functions */
 109     integer pow_ii(integer *, integer *);
 110
 111     /* Local variables */
 112     integer idel, nbit, i__, j, i2, i3, mrk;
 113
 114
 115 /*   LPC Configuration parameters: */
 116 /* Frame size, Prediction order, Pitch period */
 117 /*       Arguments */
 118
 119 /*   LPC Processing control variables: */
 120
 121 /* *** Read-only: initialized in setup */
 122
 123 /*  Files for Speech, Parameter, and Bitstream Input & Output, */
 124 /*    and message and debug outputs. */
 125
 126 /* Here are the only files which use these variables: */
 127
 128 /* lpcsim.f setup.f trans.f error.f vqsetup.f */
 129
 130 /* Many files which use fdebug are not listed, since it is only used in */
 131 /* those other files conditionally, to print trace statements. */
 132 /*      integer fsi, fso, fpi, fpo, fbi, fbo, pbin, fmsg, fdebug */
 133 /*  LPC order, Frame size, Quantization rate, Bits per frame, */
 134 /*    Error correction */
 135 /* Subroutine SETUP is the only place where order is assigned a value, */
 136 /* and that value is 10.  It could increase efficiency 1% or so to */
 137 /* declare order as a constant (i.e., a Fortran PARAMETER) instead of as
 138 */
 139 /* a variable in a COMMON block, since it is used in many places in the */
 140 /* core of the coding and decoding routines.  Actually, I take that back.
 141 */
 142 /* At least when compiling with f2c, the upper bound of DO loops is */
 143 /* stored in a local variable before the DO loop begins, and then that is
 144 */
 145 /* compared against on each iteration. */
 146 /* Similarly for lframe, which is given a value of MAXFRM in SETUP. */
 147 /* Similarly for quant, which is given a value of 2400 in SETUP.  quant */
 148 /* is used in only a few places, and never in the core coding and */
 149 /* decoding routines, so it could be eliminated entirely. */
 150 /* nbits is similar to quant, and is given a value of 54 in SETUP. */
 151 /* corrp is given a value of .TRUE. in SETUP, and is only used in the */
 152 /* subroutines ENCODE and DECODE.  It doesn't affect the speed of the */
 153 /* coder significantly whether it is .TRUE. or .FALSE., or whether it is
 154 */
 155 /* a constant or a variable, since it is only examined once per frame. */
 156 /* Leaving it as a variable that is set to .TRUE.  seems like a good */
 157 /* idea, since it does enable some error-correction capability for */
 158 /* unvoiced frames, with no change in the coding rate, and no noticeable
 159 */
 160 /* quality difference in the decoded speech. */
 161 /*      integer quant, nbits */
 162 /* *** Read/write: variables for debugging, not needed for LPC algorithm
 163 */
 164
 165 /*  Current frame, Unstable frames, Output clip count, Max onset buffer,
 166 */
 167 /*    Debug listing detail level, Line count on listing page */
 168
 169 /* nframe is not needed for an embedded LPC10 at all. */
 170 /* nunsfm is initialized to 0 in SETUP, and incremented in subroutine */
 171 /* ERROR, which is only called from RCCHK.  When LPC10 is embedded into */
 172 /* an application, I would recommend removing the call to ERROR in RCCHK,
 173 */
 174 /* and remove ERROR and nunsfm completely. */
 175 /* iclip is initialized to 0 in SETUP, and incremented in entry SWRITE in
 176 */
 177 /* sread.f.  When LPC10 is embedded into an application, one might want */
 178 /* to cause it to be incremented in a routine that takes the output of */
 179 /* SYNTHS and sends it to an audio device.  It could be optionally */
 180 /* displayed, for those that might want to know what it is. */
 181 /* maxosp is never initialized to 0 in SETUP, although it probably should
 182 */
 183 /* be, and it is updated in subroutine ANALYS.  I doubt that its value */
 184 /* would be of much interest to an application in which LPC10 is */
 185 /* embedded. */
 186 /* listl and lincnt are not needed for an embedded LPC10 at all. */
 187 /*      integer nframe, nunsfm, iclip, maxosp, listl, lincnt */
 188 /*      common /contrl/ fsi, fso, fpi, fpo, fbi, fbo, pbin, fmsg, fdebug */
 189 /*      common /contrl/ quant, nbits */
 190 /*      common /contrl/ nframe, nunsfm, iclip, maxosp, listl, lincnt */
 191 /*       Parameters/constants */
 192 /*       These arrays are not Fortran PARAMETER's, but they are defined */
 193 /*       by DATA statements below, and their contents are never altered.
 194 */
 195 /*       Local variables that need not be saved */
 196     /* Parameter adjustments */
 197     --irc;
 198     --rc;
 199     --voice;
 200
 201     /* Function Body */
 202 /*  Scale RMS and RC's to integers */
 203     *irms = *rms;
 204     i__1 = contrl_1.order;
 205     for (i__ = 1; i__ <= i__1; ++i__) {
 206         irc[i__] = rc[i__] * 32768.f;
 207     }
 208 /*      IF(LISTL.GE.3)WRITE(FDEBUG,800)VOICE,PITCH,IRMS,(IRC(I),I=1,ORDER) */
 209 /* 800  FORMAT(1X,/,' <<ENCODE IN>>',T32,2I3,I6,I5,T50,10I8) */
 210 /*  Encode pitch and voicing */
 211     if (voice[1] != 0 && voice[2] != 0) {
 212         *ipitch = entau[*pitch - 1];
 213     } else {
 214         if (contrl_1.corrp) {
 215             *ipitch = 0;
 216             if (voice[1] != voice[2]) {
 217                 *ipitch = 127;
 218             }
 219         } else {
 220             *ipitch = (voice[1] << 1) + voice[2];
 221         }
 222     }
 223 /*  Encode RMS by binary table search */
 224     j = 32;
 225     idel = 16;
 226     *irms = min(*irms,1023);
 227     while(idel > 0) {
 228         if (*irms > rmst[j - 1]) {
 229             j -= idel;
 230         }
 231         if (*irms < rmst[j - 1]) {
 232             j += idel;
 233         }
 234         idel /= 2;
 235     }
 236     if (*irms > rmst[j - 1]) {
 237         --j;
 238     }
 239     *irms = 31 - j / 2;
 240 /*  Encode RC(1) and (2) as log-area-ratios */
 241     for (i__ = 1; i__ <= 2; ++i__) {
 242         i2 = irc[i__];
 243         mrk = 0;
 244         if (i2 < 0) {
 245             i2 = -i2;
 246             mrk = 1;
 247         }
 248         i2 /= 512;
 249         i2 = min(i2,63);
 250         i2 = entab6[i2];
 251         if (mrk != 0) {
 252             i2 = -i2;
 253         }
 254         irc[i__] = i2;
 255     }
 256 /*  Encode RC(3) - (10) linearly, remove bias then scale */
 257     i__1 = contrl_1.order;
 258     for (i__ = 3; i__ <= i__1; ++i__) {
 259         i2 = irc[i__] / 2;
 260         i2 = (i2 + enadd[contrl_1.order + 1 - i__ - 1]) * enscl[
 261                 contrl_1.order + 1 - i__ - 1];
 262 /* Computing MIN */
 263         i__2 = max(i2,-127);
 264         i2 = min(i__2,127);
 265         nbit = enbits[contrl_1.order + 1 - i__ - 1];
 266         i3 = 0;
 267         if (i2 < 0) {
 268             i3 = -1;
 269         }
 270         i2 /= pow_ii(&c__2, &nbit);
 271         if (i3 == -1) {
 272             --i2;
 273         }
 274         irc[i__] = i2;
 275     }
 276 /*          Protect the most significant bits of the most */
 277 /*     important parameters during non-voiced frames. */
 278 /*     RC(1) - RC(4) are protected using 20 parity bits */
 279 /*     replacing RC(5) - RC(10). */
 280     if (contrl_1.corrp) {
 281         if (*ipitch == 0 || *ipitch == 127) {
 282             irc[5] = enctab[(irc[1] & 30) / 2];
 283             irc[6] = enctab[(irc[2] & 30) / 2];
 284             irc[7] = enctab[(irc[3] & 30) / 2];
 285             irc[8] = enctab[(*irms & 30) / 2];
 286             irc[9] = enctab[(irc[4] & 30) / 2] / 2;
 287             irc[10] = enctab[(irc[4] & 30) / 2] & 1;
 288         }
 289     }
 290 /*      IF(LISTL.GE.3)WRITE(FDEBUG,801)VOICE,IPITCH,IRMS,(IRC(J),J=1,ORDER) */
 291 /* 801  FORMAT(1X,'<<ENCODE OUT>>',T32,2I3,I6,I5,T50,10I8) */
 292     return 0;
 293 } /* encode_ */
 294