ref: 37cbdc63bc16efdd9075ab3ceb161d6cab7fc0bb
dir: /lpc10/dyptrk.c/
/* * Revision 1.2 1996/08/20 20:25:29 jaf * Removed all static local variables that were SAVE'd in the Fortran * code, and put them in struct lpc10_encoder_state that is passed as an * argument. * * Removed init function, since all initialization is now done in * init_lpc10_encoder_state(). * * Revision 1.1 1996/08/19 22:32:26 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 dyptrk_(real *amdf, integer *ltau, integer *minptr, integer *voice, integer *pitch, integer *midx, struct lpc10_encoder_state *st); /* Common Block Declarations */ extern struct { integer order, lframe; logical corrp; } contrl_; #define contrl_1 contrl_ /* ********************************************************************* */ /* DYPTRK Version 52 */ /* * Revision 1.2 1996/08/20 20:25:29 jaf * Removed all static local variables that were SAVE'd in the Fortran * code, and put them in struct lpc10_encoder_state that is passed as an * argument. * * Removed init function, since all initialization is now done in * init_lpc10_encoder_state(). * * Revision 1.1 1996/08/19 22:32:26 jaf * Initial revision * */ /* Revision 1.5 1996/03/26 19:35:35 jaf */ /* Commented out trace statements. */ /* Revision 1.4 1996/03/19 18:03:22 jaf */ /* Replaced the initialization "DATA P/60*DEPTH*0/" with "DATA P/120*0/", */ /* because apparently Fortran (or at least f2c) can't handle expressions */ /* like that. */ /* Revision 1.3 1996/03/19 17:38:32 jaf */ /* Added comments about the local variables that should be saved from one */ /* invocation to the next. None of them were given initial values in the */ /* original code, but from my testing, it appears that initializing them */ /* all to 0 works. */ /* Added entry INITDYPTRK to reinitialize these local variables. */ /* Revision 1.2 1996/03/13 16:32:17 jaf */ /* Comments added explaining which of the local variables of this */ /* subroutine need to be saved from one invocation to the next, and which */ /* do not. */ /* WARNING! Some of them that should are never given initial values in */ /* this code. Hopefully, Fortran 77 defines initial values for them, but */ /* even so, giving them explicit initial values is preferable. */ /* Revision 1.1 1996/02/07 14:45:14 jaf */ /* Initial revision */ /* ********************************************************************* */ /* Dynamic Pitch Tracker */ /* Input: */ /* AMDF - Average Magnitude Difference Function array */ /* Indices 1 through LTAU read, and MINPTR */ /* LTAU - Number of lags in AMDF */ /* MINPTR - Location of minimum AMDF value */ /* VOICE - Voicing decision */ /* Output: */ /* PITCH - Smoothed pitch value, 2 frames delayed */ /* MIDX - Initial estimate of current frame pitch */ /* Compile time constant: */ /* DEPTH - Number of frames to trace back */ /* 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 */ /* INITDYPTRK. */ /* Subroutine */ int dyptrk_(real *amdf, integer *ltau, integer * minptr, integer *voice, integer *pitch, integer *midx, struct lpc10_encoder_state *st) { /* Initialized data */ real *s; integer *p; integer *ipoint; real *alphax; /* System generated locals */ integer i__1; /* Local variables */ integer pbar; real sbar; integer iptr, i__, j; real alpha, minsc, maxsc; /* 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 */ /* Local variables that need not be saved */ /* Note that PATH is only used for debugging purposes, and can be */ /* removed. */ /* Local state */ /* It would be a bit more "general" to define S(LTAU), if Fortran */ /* allows the argument of a function to be used as the dimension of */ /* a local array variable. */ /* IPOINT is always in the range 0 to DEPTH-1. */ /* WARNING! */ /* In the original version of this subroutine, IPOINT, ALPHAX, */ /* every element of S, and potentially any element of P with the */ /* second index value .NE. IPTR were read without being given */ /* initial values (all indices of P with second index equal to */ /* IPTR are all written before being read in this subroutine). */ /* From examining the code carefully, it appears that all of these */ /* should be saved from one invocation to the next. */ /* I've run lpcsim with the "-l 6" option to see all of the */ /* debugging information that is printed out by this subroutine */ /* below, and it appears that S, P, IPOINT, and ALPHAX are all */ /* initialized to 0 (these initial values would likely be different */ /* on different platforms, compilers, etc.). Given that the output */ /* of the coder sounds reasonable, I'm going to initialize these */ /* variables to 0 explicitly. */ s = &(st->s[0]); p = &(st->p[0]); ipoint = &(st->ipoint); alphax = &(st->alphax); /* Parameter adjustments */ if (amdf) { --amdf; } /* Function Body */ /* Calculate the confidence factor ALPHA, used as a threshold slope in */ /* SEESAW. If unvoiced, set high slope so that every point in P array */ /* is marked as a potential pitch frequency. A scaled up version (ALPHAX )*/ /* is used to maintain arithmetic precision. */ if (*voice == 1) { *alphax = *alphax * .75f + amdf[*minptr] / 2.f; } else { *alphax *= .984375f; } alpha = *alphax / 16; if (*voice == 0 && *alphax < 128.f) { alpha = 8.f; } /* SEESAW: Construct a pitch pointer array and intermediate winner functio n*/ /* Left to right pass: */ iptr = *ipoint + 1; p[iptr * 60 - 60] = 1; i__ = 1; pbar = 1; sbar = s[0]; i__1 = *ltau; for (i__ = 1; i__ <= i__1; ++i__) { sbar += alpha; if (sbar < s[i__ - 1]) { s[i__ - 1] = sbar; p[i__ + iptr * 60 - 61] = pbar; } else { sbar = s[i__ - 1]; p[i__ + iptr * 60 - 61] = i__; pbar = i__; } } /* Right to left pass: */ i__ = pbar - 1; sbar = s[i__]; while(i__ >= 1) { sbar += alpha; if (sbar < s[i__ - 1]) { s[i__ - 1] = sbar; p[i__ + iptr * 60 - 61] = pbar; } else { pbar = p[i__ + iptr * 60 - 61]; i__ = pbar; sbar = s[i__ - 1]; } --i__; } /* Update S using AMDF */ /* Find maximum, minimum, and location of minimum */ s[0] += amdf[1] / 2; minsc = s[0]; maxsc = minsc; *midx = 1; i__1 = *ltau; for (i__ = 2; i__ <= i__1; ++i__) { s[i__ - 1] += amdf[i__] / 2; if (s[i__ - 1] > maxsc) { maxsc = s[i__ - 1]; } if (s[i__ - 1] < minsc) { *midx = i__; minsc = s[i__ - 1]; } } /* Subtract MINSC from S to prevent overflow */ i__1 = *ltau; for (i__ = 1; i__ <= i__1; ++i__) { s[i__ - 1] -= minsc; } maxsc -= minsc; /* Use higher octave pitch if significant null there */ j = 0; for (i__ = 20; i__ <= 40; i__ += 10) { if (*midx > i__) { if (s[*midx - i__ - 1] < maxsc / 4) { j = i__; } } } *midx -= j; /* TRACE: look back two frames to find minimum cost pitch estimate */ j = *ipoint; *pitch = *midx; for (i__ = 1; i__ <= 2; ++i__) { j = j % 2 + 1; *pitch = p[*pitch + j * 60 - 61]; } /* The following statement subtracts one from IPOINT, mod DEPTH. I */ /* think the author chose to add DEPTH-1, instead of subtracting 1, */ /* because then it will work even if MOD doesn't work as desired on */ /* negative arguments. */ *ipoint = (*ipoint + 1) % 2; return 0; } /* dyptrk_ */