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
dyptrk_(real * amdf,integer * ltau,integer * minptr,integer * voice,integer * pitch,integer * midx,struct lpc10_encoder_state * st)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_ */
343