1 /*
2 * Copyright (C) 2004-2010 NXP Software
3 * Copyright (C) 2010 The Android Open Source Project
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 #include "LVM_Types.h"
19 #include "Filter.h"
20 #include "LVM_Macros.h"
21
22 /************************************************************************************/
23 /* */
24 /* Defines and Tables for 2*Pi/Fs */
25 /* */
26 /************************************************************************************/
27
28 #define LVVDL_2PiBy_8000 1727108826 /* In Q41 format */
29 #define LVVDL_2PiBy_11025 1253230894 /* In Q41 format */
30 #define LVVDL_2PiBy_12000 1151405884 /* In Q41 format */
31
32 #define LVVDL_2PiByFs_SHIFT1 12 /* Qformat shift for 8kHz, 11.025kHz and 12kHz i.e. 12=41-29 */
33 #define LVVDL_2PiByFs_SHIFT2 13 /* Qformat shift for 16kHz, 22.050kHz and 24kHz i.e. 13=42-29 */
34 #define LVVDL_2PiByFs_SHIFT3 14 /* Qformat shift for 32kHz, 44.1kHz and 48kHz i.e. 14=43-29 */
35
36 const LVM_INT32 LVVDL_2PiOnFsTable[] = {LVVDL_2PiBy_8000 , /* 8kHz in Q41, 16kHz in Q42, 32kHz in Q43 */
37 LVVDL_2PiBy_11025, /* 11025 Hz in Q41, 22050Hz in Q42, 44100 Hz in Q43*/
38 LVVDL_2PiBy_12000}; /* 12kHz in Q41, 24kHz in Q42, 48kHz in Q43 */
39
40
41 const LVM_INT32 LVVDL_2PiOnFsShiftTable[]={LVVDL_2PiByFs_SHIFT1 , /* 8kHz, 11025Hz, 12kHz */
42 LVVDL_2PiByFs_SHIFT2, /* 16kHz, 22050Hz, 24kHz*/
43 LVVDL_2PiByFs_SHIFT3}; /* 32kHz, 44100Hz, 48kHz */
44
45 /*-------------------------------------------------------------------------*/
46 /* FUNCTION: */
47 /* LVM_GetOmega */
48 /* */
49 /* LVM_INT32 LVM_GetOmega(LVM_UINT16 Fc, */
50 /* LVM_Fs_en Fs) */
51 /* */
52 /* DESCRIPTION: */
53 /* This function calculates the value of w using Fc and Fs */
54 /* */
55 /* PARAMETERS: */
56 /* */
57 /* LVM_UINT16 Fc The corner frequency in Hz Q16.0 format */
58 /* LVM_Fs_en Fs The SampleRate */
59 /* RETURNS: */
60 /* w=2*pi*Fc/Fs in Q2.29 format */
61 /*-------------------------------------------------------------------------*/
62
LVM_GetOmega(LVM_UINT16 Fc,LVM_Fs_en Fs)63 LVM_INT32 LVM_GetOmega(LVM_UINT16 Fc,
64 LVM_Fs_en Fs)
65 {
66 LVM_INT32 w;
67 MUL32x32INTO32((LVM_INT32)Fc,LVVDL_2PiOnFsTable[Fs%3],w,LVVDL_2PiOnFsShiftTable[Fs/3])
68 return w;
69 }
70
71