/* * Copyright (C) 2004-2010 NXP Software * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "LVM_Types.h" #include "Filter.h" #include "LVM_Macros.h" /************************************************************************************/ /* */ /* Defines and Tables for 2*Pi/Fs */ /* */ /************************************************************************************/ #define LVVDL_2PiBy_8000 1727108826 /* In Q41 format */ #define LVVDL_2PiBy_11025 1253230894 /* In Q41 format */ #define LVVDL_2PiBy_12000 1151405884 /* In Q41 format */ #define LVVDL_2PiByFs_SHIFT1 12 /* Qformat shift for 8kHz, 11.025kHz and 12kHz i.e. 12=41-29 */ #define LVVDL_2PiByFs_SHIFT2 13 /* Qformat shift for 16kHz, 22.050kHz and 24kHz i.e. 13=42-29 */ #define LVVDL_2PiByFs_SHIFT3 14 /* Qformat shift for 32kHz, 44.1kHz and 48kHz i.e. 14=43-29 */ const LVM_INT32 LVVDL_2PiOnFsTable[] = {LVVDL_2PiBy_8000 , /* 8kHz in Q41, 16kHz in Q42, 32kHz in Q43 */ LVVDL_2PiBy_11025, /* 11025 Hz in Q41, 22050Hz in Q42, 44100 Hz in Q43*/ LVVDL_2PiBy_12000}; /* 12kHz in Q41, 24kHz in Q42, 48kHz in Q43 */ const LVM_INT32 LVVDL_2PiOnFsShiftTable[]={LVVDL_2PiByFs_SHIFT1 , /* 8kHz, 11025Hz, 12kHz */ LVVDL_2PiByFs_SHIFT2, /* 16kHz, 22050Hz, 24kHz*/ LVVDL_2PiByFs_SHIFT3}; /* 32kHz, 44100Hz, 48kHz */ /*-------------------------------------------------------------------------*/ /* FUNCTION: */ /* LVM_GetOmega */ /* */ /* LVM_INT32 LVM_GetOmega(LVM_UINT16 Fc, */ /* LVM_Fs_en Fs) */ /* */ /* DESCRIPTION: */ /* This function calculates the value of w using Fc and Fs */ /* */ /* PARAMETERS: */ /* */ /* LVM_UINT16 Fc The corner frequency in Hz Q16.0 format */ /* LVM_Fs_en Fs The SampleRate */ /* RETURNS: */ /* w=2*pi*Fc/Fs in Q2.29 format */ /*-------------------------------------------------------------------------*/ LVM_INT32 LVM_GetOmega(LVM_UINT16 Fc, LVM_Fs_en Fs) { LVM_INT32 w; MUL32x32INTO32((LVM_INT32)Fc,LVVDL_2PiOnFsTable[Fs%3],w,LVVDL_2PiOnFsShiftTable[Fs/3]) return w; }