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
36const 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
41const 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
63LVM_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