ref: 2024869a595118d686682b38386c594c717ea5bd
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_ */