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 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
