lpc10/dyptrk.c

   1 /*
   2
   3  * Revision 1.2  1996/08/20  20:25:29  jaf
   4  * Removed all static local variables that were SAVE'd in the Fortran
   5  * code, and put them in struct lpc10_encoder_state that is passed as an
   6  * argument.
   7  *
   8  * Removed init function, since all initialization is now done in
   9  * init_lpc10_encoder_state().
  10  *
  11  * Revision 1.1  1996/08/19  22:32:26  jaf
  12  * Initial revision
  13  *
  14
  15 */
  16
  17 /*  -- translated by f2c (version 19951025).
  18    You must link the resulting object file with the libraries:
  19         -lf2c -lm   (in that order)
  20 */
  21
  22 #include "f2c.h"
  23
  24 extern int dyptrk_(real *amdf, integer *ltau, integer *minptr, integer *voice, integer *pitch, integer *midx, struct lpc10_encoder_state *st);
  25
  26 /* Common Block Declarations */
  27
  28 extern struct {
  29     integer order, lframe;
  30     logical corrp;
  31 } contrl_;
  32
  33 #define contrl_1 contrl_
  34
  35 /* ********************************************************************* */
  36
  37 /*      DYPTRK Version 52 */
  38
  39 /*
  40  * Revision 1.2  1996/08/20  20:25:29  jaf
  41  * Removed all static local variables that were SAVE'd in the Fortran
  42  * code, and put them in struct lpc10_encoder_state that is passed as an
  43  * argument.
  44  *
  45  * Removed init function, since all initialization is now done in
  46  * init_lpc10_encoder_state().
  47  *
  48  * Revision 1.1  1996/08/19  22:32:26  jaf
  49  * Initial revision
  50  * */
  51 /* Revision 1.5  1996/03/26  19:35:35  jaf */
  52 /* Commented out trace statements. */
  53
  54 /* Revision 1.4  1996/03/19  18:03:22  jaf */
  55 /* Replaced the initialization "DATA P/60*DEPTH*0/" with "DATA P/120*0/", */
  56 /* because apparently Fortran (or at least f2c) can't handle expressions */
  57 /* like that. */
  58
  59 /* Revision 1.3  1996/03/19  17:38:32  jaf */
  60 /* Added comments about the local variables that should be saved from one */
  61 /* invocation to the next.  None of them were given initial values in the */
  62 /* original code, but from my testing, it appears that initializing them */
  63 /* all to 0 works. */
  64
  65 /* Added entry INITDYPTRK to reinitialize these local variables. */
  66
  67 /* Revision 1.2  1996/03/13  16:32:17  jaf */
  68 /* Comments added explaining which of the local variables of this */
  69 /* subroutine need to be saved from one invocation to the next, and which */
  70 /* do not. */
  71
  72 /* WARNING!  Some of them that should are never given initial values in */
  73 /* this code.  Hopefully, Fortran 77 defines initial values for them, but */
  74 /* even so, giving them explicit initial values is preferable. */
  75
  76 /* Revision 1.1  1996/02/07 14:45:14  jaf */
  77 /* Initial revision */
  78
  79
  80 /* ********************************************************************* */
  81
  82 /*   Dynamic Pitch Tracker */
  83
  84 /* Input: */
  85 /*  AMDF   - Average Magnitude Difference Function array */
  86 /*           Indices 1 through LTAU read, and MINPTR */
  87 /*  LTAU   - Number of lags in AMDF */
  88 /*  MINPTR - Location of minimum AMDF value */
  89 /*  VOICE  - Voicing decision */
  90 /* Output: */
  91 /*  PITCH  - Smoothed pitch value, 2 frames delayed */
  92 /*  MIDX   - Initial estimate of current frame pitch */
  93 /* Compile time constant: */
  94 /*  DEPTH  - Number of frames to trace back */
  95
  96 /* This subroutine maintains local state from one call to the next.  If */
  97 /* you want to switch to using a new audio stream for this filter, or */
  98 /* reinitialize its state for any other reason, call the ENTRY */
  99 /* INITDYPTRK. */
 100
 101 /* Subroutine */ int dyptrk_(real *amdf, integer *ltau, integer *
 102         minptr, integer *voice, integer *pitch, integer *midx,
 103                                struct lpc10_encoder_state *st)
 104 {
 105     /* Initialized data */
 106
 107     real *s;
 108     integer *p;
 109     integer *ipoint;
 110     real *alphax;
 111
 112     /* System generated locals */
 113     integer i__1;
 114
 115     /* Local variables */
 116     integer pbar;
 117     real sbar;
 118     integer iptr, i__, j;
 119     real alpha, minsc, maxsc;
 120
 121 /*       Arguments */
 122
 123 /*   LPC Processing control variables: */
 124
 125 /* *** Read-only: initialized in setup */
 126
 127 /*  Files for Speech, Parameter, and Bitstream Input & Output, */
 128 /*    and message and debug outputs. */
 129
 130 /* Here are the only files which use these variables: */
 131
 132 /* lpcsim.f setup.f trans.f error.f vqsetup.f */
 133
 134 /* Many files which use fdebug are not listed, since it is only used in */
 135 /* those other files conditionally, to print trace statements. */
 136 /*      integer fsi, fso, fpi, fpo, fbi, fbo, pbin, fmsg, fdebug */
 137 /*  LPC order, Frame size, Quantization rate, Bits per frame, */
 138 /*    Error correction */
 139 /* Subroutine SETUP is the only place where order is assigned a value, */
 140 /* and that value is 10.  It could increase efficiency 1% or so to */
 141 /* declare order as a constant (i.e., a Fortran PARAMETER) instead of as
 142 */
 143 /* a variable in a COMMON block, since it is used in many places in the */
 144 /* core of the coding and decoding routines.  Actually, I take that back.
 145 */
 146 /* At least when compiling with f2c, the upper bound of DO loops is */
 147 /* stored in a local variable before the DO loop begins, and then that is
 148 */
 149 /* compared against on each iteration. */
 150 /* Similarly for lframe, which is given a value of MAXFRM in SETUP. */
 151 /* Similarly for quant, which is given a value of 2400 in SETUP.  quant */
 152 /* is used in only a few places, and never in the core coding and */
 153 /* decoding routines, so it could be eliminated entirely. */
 154 /* nbits is similar to quant, and is given a value of 54 in SETUP. */
 155 /* corrp is given a value of .TRUE. in SETUP, and is only used in the */
 156 /* subroutines ENCODE and DECODE.  It doesn't affect the speed of the */
 157 /* coder significantly whether it is .TRUE. or .FALSE., or whether it is
 158 */
 159 /* a constant or a variable, since it is only examined once per frame. */
 160 /* Leaving it as a variable that is set to .TRUE.  seems like a good */
 161 /* idea, since it does enable some error-correction capability for */
 162 /* unvoiced frames, with no change in the coding rate, and no noticeable
 163 */
 164 /* quality difference in the decoded speech. */
 165 /*      integer quant, nbits */
 166 /* *** Read/write: variables for debugging, not needed for LPC algorithm
 167 */
 168
 169 /*  Current frame, Unstable frames, Output clip count, Max onset buffer,
 170 */
 171 /*    Debug listing detail level, Line count on listing page */
 172
 173 /* nframe is not needed for an embedded LPC10 at all. */
 174 /* nunsfm is initialized to 0 in SETUP, and incremented in subroutine */
 175 /* ERROR, which is only called from RCCHK.  When LPC10 is embedded into */
 176 /* an application, I would recommend removing the call to ERROR in RCCHK,
 177 */
 178 /* and remove ERROR and nunsfm completely. */
 179 /* iclip is initialized to 0 in SETUP, and incremented in entry SWRITE in
 180 */
 181 /* sread.f.  When LPC10 is embedded into an application, one might want */
 182 /* to cause it to be incremented in a routine that takes the output of */
 183 /* SYNTHS and sends it to an audio device.  It could be optionally */
 184 /* displayed, for those that might want to know what it is. */
 185 /* maxosp is never initialized to 0 in SETUP, although it probably should
 186 */
 187 /* be, and it is updated in subroutine ANALYS.  I doubt that its value */
 188 /* would be of much interest to an application in which LPC10 is */
 189 /* embedded. */
 190 /* listl and lincnt are not needed for an embedded LPC10 at all. */
 191 /*      integer nframe, nunsfm, iclip, maxosp, listl, lincnt */
 192 /*      common /contrl/ fsi, fso, fpi, fpo, fbi, fbo, pbin, fmsg, fdebug */
 193 /*      common /contrl/ quant, nbits */
 194 /*      common /contrl/ nframe, nunsfm, iclip, maxosp, listl, lincnt */
 195 /*      Parameters/constants */
 196 /*       Local variables that need not be saved */
 197 /*       Note that PATH is only used for debugging purposes, and can be */
 198 /*       removed. */
 199 /*       Local state */
 200 /*       It would be a bit more "general" to define S(LTAU), if Fortran */
 201 /*       allows the argument of a function to be used as the dimension of
 202 */
 203 /*       a local array variable. */
 204 /*       IPOINT is always in the range 0 to DEPTH-1. */
 205 /*       WARNING! */
 206
 207 /*       In the original version of this subroutine, IPOINT, ALPHAX, */
 208 /*       every element of S, and potentially any element of P with the */
 209 /*       second index value .NE. IPTR were read without being given */
 210 /*       initial values (all indices of P with second index equal to */
 211 /*       IPTR are all written before being read in this subroutine). */
 212
 213 /*       From examining the code carefully, it appears that all of these
 214 */
 215 /*       should be saved from one invocation to the next. */
 216
 217 /*       I've run lpcsim with the "-l 6" option to see all of the */
 218 /*       debugging information that is printed out by this subroutine */
 219 /*       below, and it appears that S, P, IPOINT, and ALPHAX are all */
 220 /*       initialized to 0 (these initial values would likely be different
 221 */
 222 /*       on different platforms, compilers, etc.).  Given that the output
 223 */
 224 /*       of the coder sounds reasonable, I'm going to initialize these */
 225 /*       variables to 0 explicitly. */
 226
 227     s = &(st->s[0]);
 228     p = &(st->p[0]);
 229     ipoint = &(st->ipoint);
 230     alphax = &(st->alphax);
 231
 232
 233     /* Parameter adjustments */
 234     if (amdf) {
 235         --amdf;
 236         }
 237
 238     /* Function Body */
 239
 240 /*   Calculate the confidence factor ALPHA, used as a threshold slope in
 241 */
 242 /*   SEESAW.  If unvoiced, set high slope so that every point in P array
 243 */
 244 /*  is marked as a potential pitch frequency.  A scaled up version (ALPHAX
 245 )*/
 246 /*   is used to maintain arithmetic precision. */
 247     if (*voice == 1) {
 248         *alphax = *alphax * .75f + amdf[*minptr] / 2.f;
 249     } else {
 250         *alphax *= .984375f;
 251     }
 252     alpha = *alphax / 16;
 253     if (*voice == 0 && *alphax < 128.f) {
 254         alpha = 8.f;
 255     }
 256 /* SEESAW: Construct a pitch pointer array and intermediate winner functio
 257 n*/
 258 /*   Left to right pass: */
 259     iptr = *ipoint + 1;
 260     p[iptr * 60 - 60] = 1;
 261     i__ = 1;
 262     pbar = 1;
 263     sbar = s[0];
 264     i__1 = *ltau;
 265     for (i__ = 1; i__ <= i__1; ++i__) {
 266         sbar += alpha;
 267         if (sbar < s[i__ - 1]) {
 268             s[i__ - 1] = sbar;
 269             p[i__ + iptr * 60 - 61] = pbar;
 270         } else {
 271             sbar = s[i__ - 1];
 272             p[i__ + iptr * 60 - 61] = i__;
 273             pbar = i__;
 274         }
 275     }
 276 /*   Right to left pass: */
 277     i__ = pbar - 1;
 278     sbar = s[i__];
 279     while(i__ >= 1) {
 280         sbar += alpha;
 281         if (sbar < s[i__ - 1]) {
 282             s[i__ - 1] = sbar;
 283             p[i__ + iptr * 60 - 61] = pbar;
 284         } else {
 285             pbar = p[i__ + iptr * 60 - 61];
 286             i__ = pbar;
 287             sbar = s[i__ - 1];
 288         }
 289         --i__;
 290     }
 291 /*   Update S using AMDF */
 292 /*   Find maximum, minimum, and location of minimum */
 293     s[0] += amdf[1] / 2;
 294     minsc = s[0];
 295     maxsc = minsc;
 296     *midx = 1;
 297     i__1 = *ltau;
 298     for (i__ = 2; i__ <= i__1; ++i__) {
 299         s[i__ - 1] += amdf[i__] / 2;
 300         if (s[i__ - 1] > maxsc) {
 301             maxsc = s[i__ - 1];
 302         }
 303         if (s[i__ - 1] < minsc) {
 304             *midx = i__;
 305             minsc = s[i__ - 1];
 306         }
 307     }
 308 /*   Subtract MINSC from S to prevent overflow */
 309     i__1 = *ltau;
 310     for (i__ = 1; i__ <= i__1; ++i__) {
 311         s[i__ - 1] -= minsc;
 312     }
 313     maxsc -= minsc;
 314 /*   Use higher octave pitch if significant null there */
 315     j = 0;
 316     for (i__ = 20; i__ <= 40; i__ += 10) {
 317         if (*midx > i__) {
 318             if (s[*midx - i__ - 1] < maxsc / 4) {
 319                 j = i__;
 320             }
 321         }
 322     }
 323     *midx -= j;
 324 /*   TRACE: look back two frames to find minimum cost pitch estimate */
 325     j = *ipoint;
 326     *pitch = *midx;
 327     for (i__ = 1; i__ <= 2; ++i__) {
 328         j = j % 2 + 1;
 329         *pitch = p[*pitch + j * 60 - 61];
 330     }
 331
 332 /*       The following statement subtracts one from IPOINT, mod DEPTH.  I
 333 */
 334 /*       think the author chose to add DEPTH-1, instead of subtracting 1,
 335 */
 336 /*       because then it will work even if MOD doesn't work as desired on
 337 */
 338 /*       negative arguments. */
 339
 340     *ipoint = (*ipoint + 1) % 2;
 341     return 0;
 342 } /* dyptrk_ */