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 #define LVVDL_2PiBy_8000_f 0.000785398f
36 #define LVVDL_2PiBy_11025_f 0.000569903f
37 #define LVVDL_2PiBy_12000_f 0.000523599f
38 #define LVVDL_2PiBy_16000_f 0.000392700f
39 #define LVVDL_2PiBy_22050_f 0.000284952f
40 #define LVVDL_2PiBy_24000_f 0.000261800f
41 #define LVVDL_2PiBy_32000_f 0.000196350f
42 #define LVVDL_2PiBy_44100_f 0.000142476f
43 #define LVVDL_2PiBy_48000_f 0.000130900f
44
45 #define LVVDL_2PiBy_88200_f 0.000071238f
46 #define LVVDL_2PiBy_96000_f 0.000065450f
47 #define LVVDL_2PiBy_176400_f 0.000035619f
48 #define LVVDL_2PiBy_192000_f 0.000032725f
49 const LVM_FLOAT LVVDL_2PiOnFsTable[] = {
50 LVVDL_2PiBy_8000_f, LVVDL_2PiBy_11025_f, LVVDL_2PiBy_12000_f, LVVDL_2PiBy_16000_f,
51 LVVDL_2PiBy_22050_f, LVVDL_2PiBy_24000_f, LVVDL_2PiBy_32000_f, LVVDL_2PiBy_44100_f,
52 LVVDL_2PiBy_48000_f, LVVDL_2PiBy_88200_f, LVVDL_2PiBy_96000_f, LVVDL_2PiBy_176400_f,
53 LVVDL_2PiBy_192000_f};
54 /*-------------------------------------------------------------------------*/
55 /* FUNCTION: */
56 /* LVM_GetOmega */
57 /* */
58 /* LVM_INT32 LVM_GetOmega(LVM_UINT16 Fc, */
59 /* LVM_Fs_en Fs) */
60 /* */
61 /* DESCRIPTION: */
62 /* This function calculates the value of w using Fc and Fs */
63 /* */
64 /* PARAMETERS: */
65 /* */
66 /* LVM_UINT16 Fc The corner frequency in Hz Q16.0 format */
67 /* LVM_Fs_en Fs The SampleRate */
68 /* RETURNS: */
69 /* w=2*pi*Fc/Fs in Q2.29 format */
70 /*-------------------------------------------------------------------------*/
LVM_GetOmega(LVM_UINT32 Fc,LVM_Fs_en Fs)71 LVM_FLOAT LVM_GetOmega(LVM_UINT32 Fc, LVM_Fs_en Fs) {
72 LVM_FLOAT w;
73 w = (LVM_FLOAT)Fc * LVVDL_2PiOnFsTable[Fs];
74 return w;
75 }
76