frameworks/base/media/libeffects/lvm/lib/Common/src/LVM_GetOmega.c

   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