1 /* ------------------------------------------------------------------
2 * Copyright (C) 1998-2009 PacketVideo
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
13 * express or implied.
14 * See the License for the specific language governing permissions
15 * and limitations under the License.
16 * -------------------------------------------------------------------
17 */
18 /****************************************************************************************
19 Portions of this file are derived from the following 3GPP standard:
20
21 3GPP TS 26.173
22 ANSI-C code for the Adaptive Multi-Rate - Wideband (AMR-WB) speech codec
23 Available from http://www.3gpp.org
24
25 (C) 2007, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
26 Permission to distribute, modify and use this file under the standard license
27 terms listed above has been obtained from the copyright holder.
28 ****************************************************************************************/
29 /*
30 ------------------------------------------------------------------------------
31
32
33
34 Filename: deemphasis_32.cpp
35
36 Date: 05/08/2004
37
38 ------------------------------------------------------------------------------
39 REVISION HISTORY
40
41
42 Description:
43
44 ------------------------------------------------------------------------------
45 INPUT AND OUTPUT DEFINITIONS
46
47 int16 x_hi[], (i) : input signal (bit31..16)
48 int16 x_lo[], (i) : input signal (bit15..4)
49 int16 y[], (o) : output signal (x16)
50 int16 mu, (i) Q15 : deemphasis factor
51 int16 L, (i) : vector size
52 int16 * mem (i/o) : memory (y[-1])
53
54 ------------------------------------------------------------------------------
55 FUNCTION DESCRIPTION
56
57 32-bits filtering through 1/(1-mu z^-1)
58
59 ------------------------------------------------------------------------------
60 REQUIREMENTS
61
62
63 ------------------------------------------------------------------------------
64 REFERENCES
65
66 ------------------------------------------------------------------------------
67 PSEUDO-CODE
68
69 Deemphasis H(z) = 1/(1 - 0.68z^(-1)) where mu = 0.67999 in Q15
70
71 ------------------------------------------------------------------------------
72 */
73
74
75 /*----------------------------------------------------------------------------
76 ; INCLUDES
77 ----------------------------------------------------------------------------*/
78
79 #include "pv_amr_wb_type_defs.h"
80 #include "pvamrwbdecoder_basic_op.h"
81 #include "pvamrwb_math_op.h"
82 #include "pvamrwbdecoder_acelp.h"
83
84 /*----------------------------------------------------------------------------
85 ; MACROS
86 ; Define module specific macros here
87 ----------------------------------------------------------------------------*/
88
89
90 /*----------------------------------------------------------------------------
91 ; DEFINES
92 ; Include all pre-processor statements here. Include conditional
93 ; compile variables also.
94 ----------------------------------------------------------------------------*/
95
96 /*----------------------------------------------------------------------------
97 ; LOCAL FUNCTION DEFINITIONS
98 ; Function Prototype declaration
99 ----------------------------------------------------------------------------*/
100
101 /*----------------------------------------------------------------------------
102 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
103 ; Variable declaration - defined here and used outside this module
104 ----------------------------------------------------------------------------*/
105
106 /*----------------------------------------------------------------------------
107 ; EXTERNAL FUNCTION REFERENCES
108 ; Declare functions defined elsewhere and referenced in this module
109 ----------------------------------------------------------------------------*/
110
111 /*----------------------------------------------------------------------------
112 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
113 ; Declare variables used in this module but defined elsewhere
114 ----------------------------------------------------------------------------*/
115
116 /*----------------------------------------------------------------------------
117 ; FUNCTION CODE
118 ----------------------------------------------------------------------------*/
119
deemphasis_32(int16 x_hi[],int16 x_lo[],int16 y[],int16 mu,int16 L,int16 * mem)120 void deemphasis_32(
121 int16 x_hi[], /* (i) : input signal (bit31..16) */
122 int16 x_lo[], /* (i) : input signal (bit15..4) */
123 int16 y[], /* (o) : output signal (x16) */
124 int16 mu, /* (i) Q15 : deemphasis factor */
125 int16 L, /* (i) : vector size */
126 int16 * mem /* (i/o) : memory (y[-1]) */
127 )
128 {
129 int16 i;
130 int32 L_tmp;
131 int16 lo, hi;
132
133 L_tmp = ((int32)x_hi[0]) << 16;
134 L_tmp += (((int32)x_lo[0]) << 4) & 0xFFFF;
135 L_tmp = shl_int32(L_tmp, 3);
136
137 L_tmp = fxp_mac_16by16(*mem, mu, L_tmp),
138
139 L_tmp = shl_int32(L_tmp, 1); /* saturation can occur here */
140 y[0] = amr_wb_round(L_tmp);
141
142 lo = x_lo[1];
143 hi = x_hi[1];
144 for (i = 1; i < L - 1; i++)
145 {
146 L_tmp = ((int32)hi) << 16;
147 L_tmp += (((int32)lo) << 4) & 0xFFFF;
148 L_tmp = shl_int32(L_tmp, 3);
149 L_tmp = fxp_mac_16by16(y[i - 1], mu, L_tmp),
150 L_tmp = shl_int32(L_tmp, 1); /* saturation can occur here */
151 y[i] = amr_wb_round(L_tmp);
152 lo = x_lo[i+1];
153 hi = x_hi[i+1];
154 }
155 L_tmp = ((int32)hi) << 16;
156 L_tmp += (((int32)lo) << 4) & 0xFFFF;
157 L_tmp = shl_int32(L_tmp, 3);
158 L_tmp = fxp_mac_16by16(y[i - 1], mu, L_tmp),
159 L_tmp = shl_int32(L_tmp, 1); /* saturation can occur here */
160 y[i] = amr_wb_round(L_tmp);
161
162 *mem = y[L - 1];
163
164 return;
165 }
166
167