deemphasis_32.cpp revision 4f1efc098cb5791c3e9f483f2af84aef70d2d0a0 
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/****************************************************************************************
19Portions 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)
26Permission to distribute, modify and use this file under the standard license
27terms 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
120void 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;
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;
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;
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