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comparison src/bits2prm.c @ 0:56410792419a

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src: original EFR source from ETSI
author Mychaela Falconia <falcon@freecalypso.org>
date Wed, 03 Apr 2024 05:31:37 +0000
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-1:000000000000 0:56410792419a
1 /*************************************************************************
2 *
3 * FUNCTION: Bits2prm_12k2
4 *
5 * PURPOSE: Retrieves the vector of encoder parameters from the received
6 * serial bits in a frame.
7 *
8 * DESCRIPTION: The encoder parameters are:
9 *
10 * BFI bad frame indicator 1 bit
11 *
12 * LPC:
13 * 1st codebook 7 bit
14 * 2nd codebook 8 bit
15 * 3rd codebook 8+1 bit
16 * 4th codebook 8 bit
17 * 5th codebook 6 bit
18 *
19 * 1st and 3rd subframes:
20 * pitch period 9 bit
21 * pitch gain 4 bit
22 * codebook index 35 bit
23 * codebook gain 5 bit
24 *
25 * 2nd and 4th subframes:
26 * pitch period 6 bit
27 * pitch gain 4 bit
28 * codebook index 35 bit
29 * codebook gain 5 bit
30 *
31 *************************************************************************/
32
33 #include "typedef.h"
34 #include "basic_op.h"
35 #include "count.h"
36
37 /* Local function */
38
39 Word16 Bin2int ( /* Reconstructed parameter */
40 Word16 no_of_bits, /* input : number of bits associated with value */
41 Word16 *bitstream /* output: address where bits are written */
42 );
43
44 #define BIT_0 0
45 #define BIT_1 1
46 #define PRM_NO 57
47
48 void Bits2prm_12k2 (
49 Word16 bits[], /* input : serial bits (244 + bfi) */
50 Word16 prm[] /* output: analysis parameters (57+1 parameters) */
51 )
52 {
53 Word16 i;
54
55 static const Word16 bitno[PRM_NO] =
56 {
57 7, 8, 9, 8, 6, /* LSP VQ */
58 9, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 5, /* first subframe */
59 6, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 5, /* second subframe */
60 9, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 5, /* third subframe */
61 6, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 5}; /* fourth subframe */
62
63 *prm++ = *bits++; move16 (); /* read BFI */
64
65 for (i = 0; i < PRM_NO; i++)
66 {
67 prm[i] = Bin2int (bitno[i], bits); move16 ();
68 bits += bitno[i];
69 }
70 return;
71 }
72
73 /*************************************************************************
74 *
75 * FUNCTION: Bin2int
76 *
77 * PURPOSE: Read "no_of_bits" bits from the array bitstream[] and convert
78 * to integer.
79 *
80 *************************************************************************/
81
82 Word16 Bin2int ( /* Reconstructed parameter */
83 Word16 no_of_bits, /* input : number of bits associated with value */
84 Word16 *bitstream /* output: address where bits are written */
85 )
86 {
87 Word16 value, i, bit;
88
89 value = 0; move16 ();
90 for (i = 0; i < no_of_bits; i++)
91 {
92 value = shl (value, 1);
93 bit = *bitstream++; move16 ();
94 test ();
95 if (sub (bit, BIT_1) == 0)
96 value = add (value, 1);
97 }
98 return (value);
99 }