1 /*
2 ** Copyright 2003-2010, VisualOn, Inc.
3 **
4 ** Licensed under the Apache License, Version 2.0 (the "License");
5 ** you may not use this file except in compliance with the License.
6 ** You may obtain a copy of the License at
7 **
8 ** http://www.apache.org/licenses/LICENSE-2.0
9 **
10 ** Unless required by applicable law or agreed to in writing, software
11 ** distributed under the License is distributed on an "AS IS" BASIS,
12 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 ** See the License for the specific language governing permissions and
14 ** limitations under the License.
15 */
16
17 /***********************************************************************
18 * File: syn_filt.c *
19 * *
20 * Description: Do the synthesis filtering 1/A(z) *
21 * *
22 ************************************************************************/
23
24 #include "typedef.h"
25 #include "basic_op.h"
26 #include "math_op.h"
27 #include "cnst.h"
28
29 #define UNUSED(x) (void)(x)
30
Syn_filt(Word16 a[],Word16 x[],Word16 y[],Word16 lg,Word16 mem[],Word16 update)31 void Syn_filt(
32 Word16 a[], /* (i) Q12 : a[m+1] prediction coefficients */
33 Word16 x[], /* (i) : input signal */
34 Word16 y[], /* (o) : output signal */
35 Word16 lg, /* (i) : size of filtering */
36 Word16 mem[], /* (i/o) : memory associated with this filtering. */
37 Word16 update /* (i) : 0=no update, 1=update of memory. */
38 )
39 {
40 Word32 i, a0;
41 Word16 y_buf[L_SUBFR16k + M16k];
42 Word32 L_tmp;
43 Word16 *yy, *p1, *p2;
44 yy = &y_buf[0];
45 /* copy initial filter states into synthesis buffer */
46 for (i = 0; i < 16; i++)
47 {
48 *yy++ = mem[i];
49 }
50 a0 = (a[0] >> 1); /* input / 2 */
51 /* Do the filtering. */
52 for (i = 0; i < lg; i++)
53 {
54 p1 = &a[1];
55 p2 = &yy[i-1];
56 L_tmp = vo_mult32(a0, x[i]);
57 L_tmp -= vo_mult32((*p1++), (*p2--));
58 L_tmp -= vo_mult32((*p1++), (*p2--));
59 L_tmp -= vo_mult32((*p1++), (*p2--));
60 L_tmp -= vo_mult32((*p1++), (*p2--));
61 L_tmp -= vo_mult32((*p1++), (*p2--));
62 L_tmp -= vo_mult32((*p1++), (*p2--));
63 L_tmp -= vo_mult32((*p1++), (*p2--));
64 L_tmp -= vo_mult32((*p1++), (*p2--));
65 L_tmp -= vo_mult32((*p1++), (*p2--));
66 L_tmp -= vo_mult32((*p1++), (*p2--));
67 L_tmp -= vo_mult32((*p1++), (*p2--));
68 L_tmp -= vo_mult32((*p1++), (*p2--));
69 L_tmp -= vo_mult32((*p1++), (*p2--));
70 L_tmp -= vo_mult32((*p1++), (*p2--));
71 L_tmp -= vo_mult32((*p1++), (*p2--));
72 L_tmp -= vo_mult32((*p1), (*p2));
73
74 L_tmp = L_shl2(L_tmp, 4);
75 y[i] = yy[i] = extract_h(L_add(L_tmp, 0x8000));
76 }
77 /* Update memory if required */
78 if (update)
79 for (i = 0; i < 16; i++)
80 {
81 mem[i] = yy[lg - 16 + i];
82 }
83 return;
84 }
85
86
Syn_filt_32(Word16 a[],Word16 m,Word16 exc[],Word16 Qnew,Word16 sig_hi[],Word16 sig_lo[],Word16 lg)87 void Syn_filt_32(
88 Word16 a[], /* (i) Q12 : a[m+1] prediction coefficients */
89 Word16 m, /* (i) : order of LP filter */
90 Word16 exc[], /* (i) Qnew: excitation (exc[i] >> Qnew) */
91 Word16 Qnew, /* (i) : exc scaling = 0(min) to 8(max) */
92 Word16 sig_hi[], /* (o) /16 : synthesis high */
93 Word16 sig_lo[], /* (o) /16 : synthesis low */
94 Word16 lg /* (i) : size of filtering */
95 )
96 {
97 Word32 i,a0;
98 Word32 L_tmp, L_tmp1;
99 Word16 *p1, *p2, *p3;
100 UNUSED(m);
101
102 a0 = a[0] >> (4 + Qnew); /* input / 16 and >>Qnew */
103 /* Do the filtering. */
104 for (i = 0; i < lg; i++)
105 {
106 L_tmp = 0;
107 L_tmp1 = 0;
108 p1 = a;
109 p2 = &sig_lo[i - 1];
110 p3 = &sig_hi[i - 1];
111
112 L_tmp -= vo_mult32((*p2--), (*p1));
113 L_tmp1 -= vo_mult32((*p3--), (*p1++));
114 L_tmp -= vo_mult32((*p2--), (*p1));
115 L_tmp1 -= vo_mult32((*p3--), (*p1++));
116 L_tmp -= vo_mult32((*p2--), (*p1));
117 L_tmp1 -= vo_mult32((*p3--), (*p1++));
118 L_tmp -= vo_mult32((*p2--), (*p1));
119 L_tmp1 -= vo_mult32((*p3--), (*p1++));
120 L_tmp -= vo_mult32((*p2--), (*p1));
121 L_tmp1 -= vo_mult32((*p3--), (*p1++));
122 L_tmp -= vo_mult32((*p2--), (*p1));
123 L_tmp1 -= vo_mult32((*p3--), (*p1++));
124 L_tmp -= vo_mult32((*p2--), (*p1));
125 L_tmp1 -= vo_mult32((*p3--), (*p1++));
126 L_tmp -= vo_mult32((*p2--), (*p1));
127 L_tmp1 -= vo_mult32((*p3--), (*p1++));
128 L_tmp -= vo_mult32((*p2--), (*p1));
129 L_tmp1 -= vo_mult32((*p3--), (*p1++));
130 L_tmp -= vo_mult32((*p2--), (*p1));
131 L_tmp1 -= vo_mult32((*p3--), (*p1++));
132 L_tmp -= vo_mult32((*p2--), (*p1));
133 L_tmp1 -= vo_mult32((*p3--), (*p1++));
134 L_tmp -= vo_mult32((*p2--), (*p1));
135 L_tmp1 -= vo_mult32((*p3--), (*p1++));
136 L_tmp -= vo_mult32((*p2--), (*p1));
137 L_tmp1 -= vo_mult32((*p3--), (*p1++));
138 L_tmp -= vo_mult32((*p2--), (*p1));
139 L_tmp1 -= vo_mult32((*p3--), (*p1++));
140 L_tmp -= vo_mult32((*p2--), (*p1));
141 L_tmp1 -= vo_mult32((*p3--), (*p1++));
142 L_tmp -= vo_mult32((*p2--), (*p1));
143 L_tmp1 -= vo_mult32((*p3--), (*p1++));
144
145 L_tmp = L_tmp >> 11;
146 L_tmp += vo_L_mult(exc[i], a0);
147
148 /* sig_hi = bit16 to bit31 of synthesis */
149 L_tmp = L_tmp - (L_tmp1<<1);
150
151 L_tmp = L_tmp >> 3; /* ai in Q12 */
152 sig_hi[i] = extract_h(L_tmp);
153
154 /* sig_lo = bit4 to bit15 of synthesis */
155 L_tmp >>= 4; /* 4 : sig_lo[i] >> 4 */
156 sig_lo[i] = (Word16)((L_tmp - (sig_hi[i] << 13)));
157 }
158
159 return;
160 }
161
162
163
164
165