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 /********************************************************************************** 19 INCLUDE FILES 20 ***********************************************************************************/ 21 22 #include "LVM_Types.h" 23 #include "LVM_Macros.h" 24 #include "VectorArithmetic.h" 25 26 /********************************************************************************** 27 FUNCTION DelayAllPass_32x32 28 ***********************************************************************************/ 29 30 void DelayAllPass_Sat_32x16To32( LVM_INT32 *delay, /* Delay buffer */ 31 LVM_UINT16 size, /* Delay size */ 32 LVM_INT16 coeff, /* All pass filter coefficient */ 33 LVM_UINT16 DelayOffset, /* Simple delay offset */ 34 LVM_UINT16 *pAllPassOffset, /* All pass filter delay offset */ 35 LVM_INT32 *dst, /* Source/destination */ 36 LVM_INT16 n) /* Number of samples */ 37 { 38 LVM_INT16 i; 39 LVM_UINT16 AllPassOffset = *pAllPassOffset; 40 LVM_INT32 temp; 41 LVM_INT32 a,b,c; 42 43 for (i = 0; i < n; i++) 44 { 45 46 MUL32x16INTO32(delay[AllPassOffset], coeff, temp, 15) 47 a = temp; 48 b = delay[DelayOffset]; 49 DelayOffset++; 50 51 c = a + b; 52 if ((((c ^ a) & (c ^ b)) >> 31) != 0) /* overflow / underflow */ 53 { 54 if(a < 0) 55 { 56 c = 0x80000000l; 57 } 58 else 59 { 60 c = 0x7FFFFFFFl; 61 } 62 } 63 *dst = c; 64 dst++; 65 66 67 MUL32x16INTO32(c, -coeff, temp, 15) 68 a = temp; 69 b = delay[AllPassOffset]; 70 c = a + b; 71 if ((((c ^ a) & (c ^ b)) >> 31)!=0) /* overflow / underflow */ 72 { 73 if(a < 0) 74 { 75 c = 0x80000000l; 76 } 77 else 78 { 79 c = 0x7FFFFFFFl; 80 } 81 } 82 delay[AllPassOffset] = c; 83 AllPassOffset++; 84 85 /* Make the delay buffer a circular buffer */ 86 if (DelayOffset >= size) 87 { 88 DelayOffset = 0; 89 } 90 91 if (AllPassOffset >= size) 92 { 93 AllPassOffset = 0; 94 } 95 } 96 97 /* Update the offset */ 98 *pAllPassOffset = AllPassOffset; 99 100 return; 101 } 102 103 /**********************************************************************************/ 104 105
