FreeCalypso > hg > efr-experiments

annotate src/pre_proc.c @ 0:56410792419a

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
src: original EFR source from ETSI
author Mychaela Falconia <falcon@freecalypso.org>
date Wed, 03 Apr 2024 05:31:37 +0000
parents
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
0
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*************************************************************************
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 * FUNCTION: Pre_Process()
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 * PURPOSE: Preprocessing of input speech.
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 * DESCRIPTION:
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 * - 2nd order high pass filtering with cut off frequency at 80 Hz.
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 * - Divide input by two.
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 *************************************************************************/
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 #include "typedef.h"
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 #include "basic_op.h"
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 #include "oper_32b.h"
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 #include "count.h"
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 /*------------------------------------------------------------------------*
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19 * *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 * Algorithm: *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 * *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 * y[i] = b[0]*x[i]/2 + b[1]*x[i-1]/2 + b[2]*x[i-2]/2 *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 * + a[1]*y[i-1] + a[2]*y[i-2]; *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24 * *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 * *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 * Input is divided by two in the filtering process. *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 *------------------------------------------------------------------------*/
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 /* filter coefficients (fc = 80 Hz, coeff. b[] is divided by 2) */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31 static const Word16 b[3] = {1899, -3798, 1899};
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 static const Word16 a[3] = {4096, 7807, -3733};
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 /* Static values to be preserved between calls */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35 /* y[] values are kept in double precision */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
37 static Word16 y2_hi, y2_lo, y1_hi, y1_lo, x0, x1;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 /* Initialization of static values */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41 void Init_Pre_Process (void)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
43 y2_hi = 0;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44 y2_lo = 0;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45 y1_hi = 0;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
46 y1_lo = 0;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
47 x0 = 0;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
48 x1 = 0;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
49 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
51 void Pre_Process (
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
52 Word16 signal[], /* input/output signal */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
53 Word16 lg) /* lenght of signal */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
54 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
55 Word16 i, x2;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
56 Word32 L_tmp;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
57
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
58 for (i = 0; i < lg; i++)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
59 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
60 x2 = x1; move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
61 x1 = x0; move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
62 x0 = signal[i]; move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
63
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
64 /* y[i] = b[0]*x[i]/2 + b[1]*x[i-1]/2 + b140[2]*x[i-2]/2 */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
65 /* + a[1]*y[i-1] + a[2] * y[i-2]; */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
66
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
67 L_tmp = Mpy_32_16 (y1_hi, y1_lo, a[1]);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
68 L_tmp = L_add (L_tmp, Mpy_32_16 (y2_hi, y2_lo, a[2]));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
69 L_tmp = L_mac (L_tmp, x0, b[0]);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
70 L_tmp = L_mac (L_tmp, x1, b[1]);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
71 L_tmp = L_mac (L_tmp, x2, b[2]);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
72 L_tmp = L_shl (L_tmp, 3);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
73 signal[i] = round (L_tmp); move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
74
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
75 y2_hi = y1_hi; move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
76 y2_lo = y1_lo; move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
77 L_Extract (L_tmp, &y1_hi, &y1_lo);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
78 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
79 return;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
80 }