git/lpc10/vparms.c

9 /*  -- translated by f2c (version 19951025).
11 	-lf2c -lm   (in that order)
31 /* Added some more comments about the range of INBUF and LPBUF that can */
33 /* INBUF, which might be outside of its defined range, although that will */
41 /* Finishing the job I said I did with the last check-in comments. */
60 /*  VWIN   - Voicing window limits */
62 /*  INBUF  - Input speech buffer */
63 /*           Indices START-1 through STOP read, */
67 /*  LPBUF  - Low pass filtered speech */
68 /*           Indices START-MINTAU through STOP+MINTAU read, */
71 /*  BUFLIM - Array bounds for INBUF and LPBUF */
73 /*  HALF   - Half frame (1 or 2) */
74 /*  MINTAU - Lag corresponding to minimum AMDF value (pitch estimate) */
76 /*  DITHER - Zero crossing threshold */
81 /*  ZC     - Zero crossing rate */
82 /*  LBE    - Low band energy (sum of magnitudes - SM) */
83 /*  FBE    - Full band energy (SM) */
84 /*  QS     - Ratio of 6 dB/oct preemphasized energy to full band energy */
85 /*  RC1    - First reflection coefficient */
86 /*  AR_B   - Product of the causal forward and reverse pitch */
88 /*  AR_F   - Product of the noncausal forward and reverse pitch */
91 /*  OLDSGN - Previous sign of dithered signal */
92 /*  VLEN   - Length of voicing window */
93 /*  START  - Lower address of current half of voicing window */
94 /*  STOP   - Upper address of current half of voicing window */
95 /*  E_0    - Energy of LPF speech (sum of squares - SS) */
96 /*  E_B    - Energy of LPF speech backward one pitch period (SS) */
97 /*  E_F    - Energy of LPF speech forward one pitch period (SS) */
98 /*  R_B    - Autocovariance of LPF speech backward one pitch period */
99 /*  R_F    - Autocovariance of LPF speech forward one pitch period */
100 /*  LP_RMS - Energy of LPF speech (sum of magnitudes - SM) */
101 /*  AP_RMS - Energy of all-pass speech (SM) */
102 /*  E_PRE  - Energy of 6dB preemphasized speech (SM) */
103 /*  E0AP   - Energy of all-pass speech (SS) */
133     --vwin;  in vparms_()
134     --buflim;  in vparms_()
136     lpbuf -= lpbuf_offset;  in vparms_()
138     inbuf -= inbuf_offset;  in vparms_()
152     vlen = vwin[2] - vwin[1] + 1;  in vparms_()
153     start = vwin[1] + (*half - 1) * vlen / 2 + 1;  in vparms_()
154     stop = start + vlen / 2 - 1;  in vparms_()
158 /* i.e., HVL = (VLEN-1)/2. */  in vparms_()
169     r__1 = inbuf[start - 1] - *dither;  in vparms_()
173 	lp_rms__ += (r__1 = lpbuf[i__], abs(r__1));  in vparms_()
174 	ap_rms__ += (r__1 = inbuf[i__], abs(r__1));  in vparms_()
175 	e_pre__ += (r__1 = inbuf[i__] - inbuf[i__ - 1], abs(r__1));  in vparms_()
179 	*rc1 += inbuf[i__] * inbuf[i__ - 1];  in vparms_()
184 	r__1 = lpbuf[i__ - *mintau];  in vparms_()
190 	r_b__ += lpbuf[i__] * lpbuf[i__ - *mintau];  in vparms_()
194 	    oldsgn = -oldsgn;  in vparms_()
196 	*dither = -(*dither);  in vparms_()
198 /*   Normalized short-term autocovariance coefficient at unit sample delay  in vparms_()
214 /*   (The fraction 90/VLEN has a range of .58 to 1) */  in vparms_()