FreeCalypso > hg > gsm-codec-lib
annotate libgsmefr/az_lsp.c @ 53:49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Fri, 25 Nov 2022 16:18:21 +0000 |
parents | |
children | 902bc4b64cc6 |
rev | line source |
---|---|
53
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
1 /*********************************************************************** |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
2 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
3 * FUNCTION: Az_lsp |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
4 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
5 * PURPOSE: Compute the LSPs from the LP coefficients (order=10) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
6 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
7 * DESCRIPTION: |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
8 * - The sum and difference filters are computed and divided by |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
9 * 1+z^{-1} and 1-z^{-1}, respectively. |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
10 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
11 * f1[i] = a[i] + a[11-i] - f1[i-1] ; i=1,...,5 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
12 * f2[i] = a[i] - a[11-i] + f2[i-1] ; i=1,...,5 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
13 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
14 * - The roots of F1(z) and F2(z) are found using Chebyshev polynomial |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
15 * evaluation. The polynomials are evaluated at 60 points regularly |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
16 * spaced in the frequency domain. The sign change interval is |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
17 * subdivided 4 times to better track the root. |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
18 * The LSPs are found in the cosine domain [1,-1]. |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
19 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
20 * - If less than 10 roots are found, the LSPs from the past frame are |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
21 * used. |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
22 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
23 ***********************************************************************/ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
24 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
25 #include "typedef.h" |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
26 #include "basic_op.h" |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
27 #include "oper_32b.h" |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
28 #include "count.h" |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
29 #include "cnst.h" |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
30 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
31 #include "grid.tab" |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
32 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
33 /* M = LPC order, NC = M/2 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
34 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
35 #define NC M/2 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
36 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
37 /* local function */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
38 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
39 static Word16 Chebps (Word16 x, Word16 f[], Word16 n); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
40 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
41 void Az_lsp ( |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
42 Word16 a[], /* (i) : predictor coefficients */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
43 Word16 lsp[], /* (o) : line spectral pairs */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
44 Word16 old_lsp[] /* (i) : old lsp[] (in case not found 10 roots) */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
45 ) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
46 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
47 Word16 i, j, nf, ip; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
48 Word16 xlow, ylow, xhigh, yhigh, xmid, ymid, xint; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
49 Word16 x, y, sign, exp; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
50 Word16 *coef; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
51 Word16 f1[M / 2 + 1], f2[M / 2 + 1]; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
52 Word32 t0; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
53 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
54 /*-------------------------------------------------------------* |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
55 * find the sum and diff. pol. F1(z) and F2(z) * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
56 * F1(z) <--- F1(z)/(1+z**-1) & F2(z) <--- F2(z)/(1-z**-1) * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
57 * * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
58 * f1[0] = 1.0; * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
59 * f2[0] = 1.0; * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
60 * * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
61 * for (i = 0; i< NC; i++) * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
62 * { * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
63 * f1[i+1] = a[i+1] + a[M-i] - f1[i] ; * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
64 * f2[i+1] = a[i+1] - a[M-i] + f2[i] ; * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
65 * } * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
66 *-------------------------------------------------------------*/ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
67 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
68 f1[0] = 1024; move16 (); /* f1[0] = 1.0 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
69 f2[0] = 1024; move16 (); /* f2[0] = 1.0 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
70 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
71 for (i = 0; i < NC; i++) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
72 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
73 t0 = L_mult (a[i + 1], 8192); /* x = (a[i+1] + a[M-i]) >> 2 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
74 t0 = L_mac (t0, a[M - i], 8192); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
75 x = extract_h (t0); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
76 /* f1[i+1] = a[i+1] + a[M-i] - f1[i] */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
77 f1[i + 1] = sub (x, f1[i]);move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
78 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
79 t0 = L_mult (a[i + 1], 8192); /* x = (a[i+1] - a[M-i]) >> 2 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
80 t0 = L_msu (t0, a[M - i], 8192); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
81 x = extract_h (t0); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
82 /* f2[i+1] = a[i+1] - a[M-i] + f2[i] */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
83 f2[i + 1] = add (x, f2[i]);move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
84 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
85 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
86 /*-------------------------------------------------------------* |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
87 * find the LSPs using the Chebychev pol. evaluation * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
88 *-------------------------------------------------------------*/ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
89 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
90 nf = 0; move16 (); /* number of found frequencies */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
91 ip = 0; move16 (); /* indicator for f1 or f2 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
92 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
93 coef = f1; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
94 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
95 xlow = grid[0]; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
96 ylow = Chebps (xlow, coef, NC);move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
97 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
98 j = 0; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
99 test (); test (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
100 /* while ( (nf < M) && (j < grid_points) ) */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
101 while ((sub (nf, M) < 0) && (sub (j, grid_points) < 0)) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
102 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
103 j++; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
104 xhigh = xlow; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
105 yhigh = ylow; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
106 xlow = grid[j]; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
107 ylow = Chebps (xlow, coef, NC); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
108 move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
109 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
110 test (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
111 if (L_mult (ylow, yhigh) <= (Word32) 0L) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
112 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
113 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
114 /* divide 4 times the interval */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
115 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
116 for (i = 0; i < 4; i++) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
117 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
118 /* xmid = (xlow + xhigh)/2 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
119 xmid = add (shr (xlow, 1), shr (xhigh, 1)); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
120 ymid = Chebps (xmid, coef, NC); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
121 move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
122 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
123 test (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
124 if (L_mult (ylow, ymid) <= (Word32) 0L) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
125 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
126 yhigh = ymid; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
127 xhigh = xmid; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
128 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
129 else |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
130 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
131 ylow = ymid; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
132 xlow = xmid; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
133 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
134 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
135 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
136 /*-------------------------------------------------------------* |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
137 * Linear interpolation * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
138 * xint = xlow - ylow*(xhigh-xlow)/(yhigh-ylow); * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
139 *-------------------------------------------------------------*/ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
140 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
141 x = sub (xhigh, xlow); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
142 y = sub (yhigh, ylow); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
143 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
144 test (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
145 if (y == 0) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
146 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
147 xint = xlow; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
148 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
149 else |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
150 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
151 sign = y; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
152 y = abs_s (y); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
153 exp = norm_s (y); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
154 y = shl (y, exp); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
155 y = div_s ((Word16) 16383, y); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
156 t0 = L_mult (x, y); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
157 t0 = L_shr (t0, sub (20, exp)); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
158 y = extract_l (t0); /* y= (xhigh-xlow)/(yhigh-ylow) */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
159 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
160 test (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
161 if (sign < 0) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
162 y = negate (y); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
163 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
164 t0 = L_mult (ylow, y); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
165 t0 = L_shr (t0, 11); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
166 xint = sub (xlow, extract_l (t0)); /* xint = xlow - ylow*y */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
167 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
168 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
169 lsp[nf] = xint; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
170 xlow = xint; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
171 nf++; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
172 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
173 test (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
174 if (ip == 0) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
175 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
176 ip = 1; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
177 coef = f2; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
178 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
179 else |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
180 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
181 ip = 0; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
182 coef = f1; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
183 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
184 ylow = Chebps (xlow, coef, NC); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
185 move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
186 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
187 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
188 test (); test (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
189 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
190 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
191 /* Check if M roots found */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
192 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
193 test (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
194 if (sub (nf, M) < 0) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
195 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
196 for (i = 0; i < M; i++) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
197 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
198 lsp[i] = old_lsp[i]; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
199 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
200 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
201 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
202 return; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
203 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
204 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
205 /************************************************************************ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
206 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
207 * FUNCTION: Chebps |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
208 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
209 * PURPOSE: Evaluates the Chebyshev polynomial series |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
210 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
211 * DESCRIPTION: |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
212 * - The polynomial order is n = m/2 = 5 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
213 * - The polynomial F(z) (F1(z) or F2(z)) is given by |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
214 * F(w) = 2 exp(-j5w) C(x) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
215 * where |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
216 * C(x) = T_n(x) + f(1)T_n-1(x) + ... +f(n-1)T_1(x) + f(n)/2 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
217 * and T_m(x) = cos(mw) is the mth order Chebyshev polynomial ( x=cos(w) ) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
218 * - The function returns the value of C(x) for the input x. |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
219 * |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
220 ***********************************************************************/ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
221 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
222 static Word16 Chebps (Word16 x, Word16 f[], Word16 n) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
223 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
224 Word16 i, cheb; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
225 Word16 b0_h, b0_l, b1_h, b1_l, b2_h, b2_l; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
226 Word32 t0; |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
227 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
228 b2_h = 256; move16 (); /* b2 = 1.0 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
229 b2_l = 0; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
230 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
231 t0 = L_mult (x, 512); /* 2*x */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
232 t0 = L_mac (t0, f[1], 8192); /* + f[1] */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
233 L_Extract (t0, &b1_h, &b1_l); /* b1 = 2*x + f[1] */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
234 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
235 for (i = 2; i < n; i++) |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
236 { |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
237 t0 = Mpy_32_16 (b1_h, b1_l, x); /* t0 = 2.0*x*b1 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
238 t0 = L_shl (t0, 1); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
239 t0 = L_mac (t0, b2_h, (Word16) 0x8000); /* t0 = 2.0*x*b1 - b2 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
240 t0 = L_msu (t0, b2_l, 1); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
241 t0 = L_mac (t0, f[i], 8192); /* t0 = 2.0*x*b1 - b2 + f[i] */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
242 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
243 L_Extract (t0, &b0_h, &b0_l); /* b0 = 2.0*x*b1 - b2 + f[i]*/ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
244 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
245 b2_l = b1_l; move16 (); /* b2 = b1; */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
246 b2_h = b1_h; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
247 b1_l = b0_l; move16 (); /* b1 = b0; */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
248 b1_h = b0_h; move16 (); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
249 } |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
250 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
251 t0 = Mpy_32_16 (b1_h, b1_l, x); /* t0 = x*b1; */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
252 t0 = L_mac (t0, b2_h, (Word16) 0x8000); /* t0 = x*b1 - b2 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
253 t0 = L_msu (t0, b2_l, 1); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
254 t0 = L_mac (t0, f[i], 4096); /* t0 = x*b1 - b2 + f[i]/2 */ |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
255 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
256 t0 = L_shl (t0, 6); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
257 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
258 cheb = extract_h (t0); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
259 |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
260 return (cheb); |
49dd1ac8e75b
libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
261 } |