Android 50 Camera系统源码分析5Camera预览3A流程.docx
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Android50Camera系统源码分析5Camera预览3A流程
Android5.0Camera系统源码分析(5):
Camera预览3A流程
1.前言
本文分析的是AndroidHal层的源码,硬件平台基于mt6735。
之前几篇讲的预览流程中3A相关的环节都忽略了,现在重新整理下。
3A指的是AutoExposure,AutoFocus,AutoWhiteBalance。
这三个一起放上来代码实在太多了,这里将重点记录AF的代码。
AF的部分工作是由ISP完成的,而ISP的大部分代码mtk都没有开放给我们,比如ISP是如何计算得到对焦位置信息的,但得到对焦位置之后怎么操作对焦马达的代码我们是看得到的,所以涉及到ISP的一些代码将被略过
2.初始化3A
3A的初始化在DefaultCam1Device的onInit函数里面开始,之前在camera打开流程里面已经提到过
bool
DefaultCam1Device:
:
onInit()
{
......
//
(1)Open3A
mpHal3a=NS3A:
:
IHal3A:
:
createInstance(
NS3A:
:
IHal3A:
:
E_Camera_1,
getOpenId(),
LOG_TAG);
......
}
构造一个Hal3A对象,看下Hal3A:
:
createInstance的实现
Hal3A*
Hal3A:
:
createInstance(MINT32i4SensorDevId,MINT32i4SensorOpenIndex)
{
switch(i4SensorDevId)
{
caseSENSOR_DEV_MAIN:
Hal3ADev:
:
getInstance()->init(i4SensorDevId,i4SensorOpenIndex);
returnHal3ADev:
:
getInstance();
break;
caseSENSOR_DEV_SUB:
Hal3ADev:
:
getInstance()->init(i4SensorDevId,i4SensorOpenIndex);
returnHal3ADev:
:
getInstance();
break;
......
}
}
其实这里的Hal3A并没有直接继承IHal3A,也就是说从IHal3A:
:
createInstance到Hal3A:
:
createInstance的调用过程经历了一番波折,但暂时不用关心它。
从Hal3A:
:
createInstance可以看到除了实例化以外还会调用init函数。
构造函数没什么好看的-略过,直接看init函数
MRESULT
Hal3A:
:
init(MINT32i4SensorDevId,MINT32i4SensorOpenIndex)
{
......
//
(1)
mpStateMgr=newStateMgr(i4SensorDevId);
//
(2)
bRet=postCommand(ECmd_Init);
//(3)
createThread();
//(4)
bRet=IspTuningMgr:
:
getInstance().init(m_i4SensorDev,m_i4SensorOpenIdx);
//(5)
ret=EnableAFThread
(1);
......
returnS_3A_OK;
}
步骤
(1)newStateMgr,构造函数如下
StateMgr:
:
StateMgr(MINT32sensorDevId)
:
......
{
#defineSTATE_INITIALIZE(_state_)\
mpIState[eState_##_state_]=newState##_state_(sensorDevId,this);
STATE_INITIALIZE(Init);
STATE_INITIALIZE(Uninit);
STATE_INITIALIZE(CameraPreview);
STATE_INITIALIZE(CamcorderPreview);
STATE_INITIALIZE(Recording);
STATE_INITIALIZE(Precapture);
STATE_INITIALIZE(Capture);
STATE_INITIALIZE(AF);
mpCurrentState=mpIState[eState_Uninit];
}
初始化3A的状态管理,将各个子状态都保存在mpIState数组里面,并将当前状态设置为Uninit状态
步骤
(2)postCommand
MBOOLHal3A:
:
postCommand(ECmd_TconsteCmd,MINTPTRconsti4Arg)
{
......
ERROR_CHECK(mpStateMgr->sendCmd(eCmd))
......
}
MRESULTStateMgr:
:
sendCmd(ECmd_TeCmd)
{
Mutex:
:
Autolocklock(m_Lock);
EIntent_TeNewIntent=static_cast(eCmd);
#defineSEND_INTENT(_intent_)\
case_intent_:
returnmpCurrentState->sendIntent(intent2type<_intent_>());\
switch(eNewIntent)
{
SEND_INTENT(eIntent_CameraPreviewStart)
SEND_INTENT(eIntent_CameraPreviewEnd)
SEND_INTENT(eIntent_CaptureStart)
SEND_INTENT(eIntent_CaptureEnd)
SEND_INTENT(eIntent_RecordingStart)
SEND_INTENT(eIntent_RecordingEnd)
SEND_INTENT(eIntent_AFUpdate)
SEND_INTENT(eIntent_AFStart)
SEND_INTENT(eIntent_AFEnd)
SEND_INTENT(eIntent_Init)
SEND_INTENT(eIntent_Uninit)
}
return-1;
}
从步骤
(1)可以看出这里的mpCurrentState指向的是StateUninit对象,所以接着看StateUninit的sendIntent函数
MRESULT
StateUninit:
:
sendIntent(intent2type)
{
MY_LOG("[StateUninit:
:
sendIntent]");
//AAODMAbufferinit
MINT32i4SensorIdx=m_pHal3A->getSensorOpenIdx();
if(ENABLE_3A_GENERAL&m_pHal3A->m_3ACtrlEnable){
if(ENABLE_AAOBUF&m_pHal3A->m_3ACtrlEnable){
//AAODMAbufferinit
if(!
IAAOBufMgr:
:
getInstance().init(m_SensorDevId,i4SensorIdx)){
MY_ERR("IAAOBufMgr:
:
getInstance().init()fail");
returnE_3A_ERR;
}
if(!
IAEBufMgr:
:
getInstance().init(m_SensorDevId,i4SensorIdx)){
MY_ERR("IAEBufMgr:
:
getInstance().init()fail");
returnE_3A_ERR;
}
}
if(ENABLE_AFOBUF&m_pHal3A->m_3ACtrlEnable){
//AFODMAbufferinit
if(!
IAFOBufMgr:
:
getInstance().init(m_SensorDevId,i4SensorIdx)){
MY_ERR("IAFOBufMgr:
:
getInstance().init()fail");
returnE_3A_ERR;
}
}
}
//Statetransition:
eState_Uninit-->eState_Init
m_pStateMgr->transitState(eState_Uninit,eState_Init);
returnS_3A_OK;
}
做了一堆乱七八糟的初始化之后将3A状态从Uninit状态切换到Init状态
步骤(3)createThread和步骤(5)EnableAFThread
MVOID
Hal3A:
:
createThread()
{
......
pthread_create(&mThread,NULL,onThreadLoop,this);
pthread_create(&mPDThread,NULL,PDThreadLoop,this);
pthread_create(&mPDVCThread,NULL,PDVCThreadLoop,this);
......
}
MRESULTHal3A:
:
EnableAFThread(MINT32a_bEnable)
{
if(a_bEnable){
if(mbAFThreadLoop==0)
{
......
pthread_create(&mAFThread,&attr,AFThreadFunc,this);
}
}else{
......
}
returnret;
}
一共创建了4个线程,暂时只关心onThreadLoop和AFThreadFunc。
onThreadLoop是3A主线程,负责接收处理命令;AFThreadFunc负责实时更新AF参数
3.处理PASS1_START_ISP事件
前面的3A初始化做的事情并不多,更多的准备工作是在接收到PASS1_START_ISP事件之后做的,PASS1_START_ISP事件是在之前的Camera预览流程控制流中提到的Pass1Node的startHw函数里面发送
MBOOL
Pass1NodeImpl:
:
startHw(list&plPortCfg)
{
......
handleNotify(PASS1_START_ISP,newMagicNum,0);
......
}
3.1DefaultCtrlNode接收处理PASS1_START_ISP事件
Pass1Node发出的event将在DefaultCtrlNode的onNotify函数中接收处理
MBOOL
DefaultCtrlNodeImpl:
:
onNotify(MUINT32constmsg,MUINT32constext1,MUINT32constext2)
{
switch(msg)
{
casePASS1_START_ISP:
{
if(mpHal3a)
{
cmd=ECmd_CameraPreviewStart;
......
mpHal3a->sendCommand(cmd);
}
casePASS1_STOP_ISP:
{
......
}
casePASS1_EOF:
{
......
}
default:
{
ret=MTRUE;
}
}
returnret;
}
Hal3a的sendCommand函数会把命令加入到命令队列,然后由主线程onThreadLoop获取
MVOID*
Hal3A:
:
onThreadLoop(MVOID*arg)
{
while(_this->getCommand(rCmd,bGetCmd,MFALSE))
{
switch(rCmd.eCmd)
{
caseECmd_PrecaptureStart:
{
......
}
caseECmd_Update:
{
......
}
default:
if(!
_this->postCommand(rCmd.eCmd,reinterpret_cast(&rCmd.rParamIspProfile)))
{
MY_ERR("Cmd(%d)failed(0x%x)",rCmd.eCmd,_this->getErrorCode());
AEE_ASSERT_3A_HAL("onThreadLooppostCommandfail
(2).");
}
}
}
}
onThreadLoop通过getCommand函数获取命令,获取到命令之后调用postCommand函数对命令进行处理
再看一次postCommand
MBOOLHal3A:
:
postCommand(ECmd_TconsteCmd,MINTPTRconsti4Arg)
{
if(eCmd==ECmd_CameraPreviewStart||eCmd==ECmd_CaptureStart)
{
mbEnAESenThd=MTRUE;
createAEThread();
mEnFlushVSIrq=mFlushVSIrqDone=0;
mEnFlushAFIrq=mFlushAFIrqDone=0;
}
......
ERROR_CHECK(mpStateMgr->sendCmd(eCmd))
......
returnMTRUE;
}
接收到的命令是ECmd_CameraPreviewStart,所以这里的createAEThread函数会执行
MVOID
Hal3A:
:
createAEThread()
{
pthread_create(&mAESenThread,NULL,AESensorThreadLoop,this);
}
加上这个AESensorThreadLoop,需要关注的线程增加到了3个
3.2StateInit处理CameraPreviewStart命令
继续看mpStateMgr->sendCmd函数。
之前介绍过,它会把命令交给当前状态的sendIntent函数进行处理。
在初始化阶段已经把当前状态切换到init状态,所以来看StateInit的sendIntent的实现
MRESULT
StateInit:
:
sendIntent(intent2type)
{
if(ENABLE_3A_GENERAL&m_pHal3A->m_3ACtrlEnable){
if(ENABLE_AAOBUF&m_pHal3A->m_3ACtrlEnable){
//AAODMAInit+AAStatEnable
if(!
IAAOBufMgr:
:
getInstance().DMAInit(m_SensorDevId)){
MY_ERR("IAAOBufMgr:
:
getInstance().DMAInit()fail");
returnE_3A_ERR;
}
if(!
IAAOBufMgr:
:
getInstance().AAStatEnable(m_SensorDevId,MTRUE)){
MY_ERR("IAAOBufMgr:
:
getInstance().AAStatEnable()fail");
returnE_3A_ERR;
}
if(!
IAEBufMgr:
:
getInstance().DMAInit(m_SensorDevId)){
MY_ERR("IAEBufMgr:
:
getInstance().DMAInit()fail");
returnE_3A_ERR;
}
if(!
IAEBufMgr:
:
getInstance().AAStatEnable(m_SensorDevId,MTRUE)){
MY_ERR("IAEBufMgr:
:
getInstance().AAStatEnable()fail");
returnE_3A_ERR;
}
}
if(ENABLE_AFOBUF&m_pHal3A->m_3ACtrlEnable){
//AFODMAInit+AFStatEnable
if(!
IAFOBufMgr:
:
getInstance().DMAInit(m_SensorDevId)){
MY_ERR("IAFOBufMgr:
:
getInstance().DMAInit()fail");
returnE_3A_ERR;
}
if(!
IAFOBufMgr:
:
getInstance().AFStatEnable(m_SensorDevId,MTRUE)){
MY_ERR("IAFOBufMgr:
:
getInstance().AFStatEnable()fail");
returnE_3A_ERR;
}
}
......
if(ENABLE_AWB&m_pHal3A->m_3ACtrlEnable){
//AWBinit
bRet=(m_pHal3A->get3APreviewMode()==EPv_Normal)
?
IAwbMgr:
:
getInstance().cameraPreviewInit(m_SensorDevId,i4SensorIdx,rParam)
:
IAwbMgr:
:
getInstance().camcorderPreviewInit(m_SensorDevId,i4SensorIdx,rParam);
if(!
bRet){
MY_ERR("IAwbMgr:
:
getInstance().PreviewInit()fail,PvMode=%d\n",m_pHal3A->get3APreviewMode());
returnE_3A_ERR;
}
}
if(ENABLE_AE&m_pHal3A->m_3ACtrlEnable){
//AEinit
err=(m_pHal3A->get3APreviewMode()==EPv_Normal)
?
IAeMgr:
:
getInstance().cameraPreviewInit(m_SensorDevId,i4SensorIdx,rParam)
:
IAeMgr:
:
getInstance().camcorderPreviewInit(m_SensorDevId,i4SensorIdx,rParam);
if(FAILED(err)){
MY_ERR("IAeMgr:
:
getInstance().PreviewInit()fail,PvMode=%d\n",m_pHal3A->get3APreviewMode());
returnerr;
}
}
if(ENABLE_AF&m_pHal3A->m_3ACtrlEnable){
//AFinit
err=IAfMgr:
:
getInstance().init(m_SensorDevId,i4SensorIdx);
if(FAILED(err)){
MY_ERR("AfMgr:
:
getInstance().init()fail\n");
returnerr;
}
}
IspTuningMgr:
:
getInstance().sendIspTuningIOCtrl(m_SensorDevId,IspTuningMgr:
:
E_ISPTUNING_SET_GMA_SCENARIO,IspTuningMgr:
:
E_GMA_SCENARIO_PREVIEW,0);
IspTuningMgr:
:
getInstance().sendIspTuningIOCtrl(m_SensorDevId,IspTuningMgr:
:
E_ISPTUNING_NOTIFY_START,0,0);
//Resetframecountto-2
m_pStateMgr->resetFrameCount();
//Statetransition:
eState_Init-->eState_CameraPreview
m_pStateMgr->transitState(eState_Init,eState_CameraPreview);
returnS_3A_OK;
}
包含了AWB、AE、AF在内的ISP相关的初始化,相关的初始化完成之后会调用m_pStateMgr->transitState函数将当前状态切换到CameraPreview状态。
代码太多,这里只关注AF的初始化
MRESULTAfMgr:
:
init(MINT32i4SensorIdx,MINT32isInitMCU)
{
......
//---initMCU---
SensorStaticInforSensorStaticInfo;
if(m_i4EnableAF==-1)
{
IHalSensorList*constpIHalSensorList=IHalSensorList:
:
get();
IHalSensor*pIHalSensor=pIHalSensorList->createSensor("af_mgr",m_i4SensorIdx);
SensorDynamicInforSensorDynamicInfo;
switch(m_i4CurrSensorDev)
{
caseESensorDev_Main:
pIHalSensorList->querySensorStaticInfo(NSCam:
:
SENSOR_DEV_MAIN,&rSensorStaticInfo);
pIHalSensor->querySensorDynamicInfo(NSCam:
:
SENSOR_DEV_MAIN,&rSensorDynamicInf