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 "LVM_Macros.h"
20 #include "LVC_Mixer_Private.h"
21
22 /************************************************************************/
23 /* FUNCTION: */
24 /* LVMixer3_SetTarget */
25 /* */
26 /* DESCRIPTION: */
27 /* This function updates the private instance parameters: Shift,Target,*/
28 /* Current for a given Audio Stream based on new value of TargetGain */
29 /* */
30 /* This function caclulates the "Shift" required to provide the */
31 /* integer part of TargetGain and fractional gain values "Target" and */
32 /* "Current" based on maximum(TargetGain,CurrentGain) */
33 /* E.g. CurrentGain=1.9 and TargetGain=2.5 then based on */
34 /* MaxGain of 2.5, Shift = 2, Current=1.9/4=0.475, Target=2.5/4=0.625 */
35 /* Therefore integer gain of 4 is provided by Left Shift of 2 and */
36 /* fraction gain is provided through Current=0.475 and Target=0.625 */
37 /* PARAMETERS: */
38 /* pStream - ptr to Instance Parameter Structure LVMixer3_st */
39 /* for an Audio Stream */
40 /* TargetGain - TargetGain value in Q 16.15 format */
41 /* */
42 /* RETURNS: */
43 /* void */
44 /* */
45 /************************************************************************/
LVC_Mixer_SetTarget(LVMixer3_FLOAT_st * pStream,LVM_FLOAT TargetGain)46 void LVC_Mixer_SetTarget(LVMixer3_FLOAT_st *pStream,
47 LVM_FLOAT TargetGain)
48 {
49 Mix_Private_FLOAT_st *pInstance = (Mix_Private_FLOAT_st *)pStream->PrivateParams;
50 pInstance->Target = TargetGain; // Update gain Target
51 }
52