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全部博文（113）
2013年（113）
分类： Android平台
2013-04-18 10:45:27
在之前的文章中已经说过OMXCameraAdapter的初始化了,为了更好的了解A9和Ducati的数据交互过程,这里很有必要深入研究一下Camera采用OMX方式的Preview过程
这里还是废话一点吧,最近编辑好博客,发布时总会出现莫名其妙的问题,害的我辛辛苦苦编辑好的文章,无缘无故就消失了,郁闷啊!现在转做在word下编辑了,本来发布博客就是为了保存自己的学习思路,同时大家能互相学习,往ChinaUnix加油改进吧!愿望越做越好.
不多说了,开始了,嘻嘻
这里我们还是从CameraHal开始我们对preview过程的分析吧,因为hal层的preview方法对整个preview过程做了一些很重要的初始化,看看代码吧
/**
@brief Start preview mode.
@param none
@return NO_ERROR Camera switched to VF mode
@todo Update function header with the different errors that are possible
*/
status_t CameraHal::startPreview() {
LOG_FUNCTION_NAME;
// When tunneling is enabled during VTC, startPreview happens in 2 steps:
// When the application sends the command CAMERA_CMD_PREVIEW_INITIALIZATION,
// cameraPreviewInitialization() is called, which in turn causes the CameraAdapter
// to move from loaded to idle state. And when the application calls startPreview,
// the CameraAdapter moves from idle to executing state.
//
// If the application calls startPreview() without sending the command
// CAMERA_CMD_PREVIEW_INITIALIZATION, then the function cameraPreviewInitialization()
// AND startPreview() are executed. In other words, if the application calls
// startPreview() without sending the command CAMERA_CMD_PREVIEW_INITIALIZATION,
// then the CameraAdapter moves from loaded to idle to executing state in one shot.
下面调用的这个方法是我们关注的重点,他实现了很多preview开始前的初始化
status_t ret = cameraPreviewInitialization();
// The flag mPreviewInitializationDone is set to true at the end of the function
// cameraPreviewInitialization(). Therefore, if everything goes alright, then the
// flag will be set. Sometimes, the function cameraPreviewInitialization() may
// return prematurely if all the resources are not available for starting preview.
// For example, if the preview window is not set, then it would return NO_ERROR.
// Under such circumstances, one should return from startPreview as well and should
// not continue execution. That is why, we check the flag and not the return value.
if (!mPreviewInitializationDone) return ret;
// Once startPreview is called, there is no need to continue to remember whether
// the function cameraPreviewInitialization() was called earlier or not. And so
// the flag mPreviewInitializationDone is reset here. Plus, this preserves the
// current behavior of startPreview under the circumstances where the application
// calls startPreview twice or more.
mPreviewInitializationDone = false;
///Enable the display adapter if present, actual overlay enable happens when we post the buffer
这里判断我们是否使用overlay方法,如果我们使用overlay方法,则这里会开启DisplayAdapter显示
if(mDisplayAdapter.get() != NULL) {
CAMHAL_LOGDA("Enabling display");
int width, height;
mParameters.getPreviewSize(&width, &height);
#if PPM_INSTRUMENTATION || PPM_INSTRUMENTATION_ABS
ret = mDisplayAdapter->enableDisplay(width, height, &mStartPreview);
#else
ret = mDisplayAdapter->enableDisplay(width, height, NULL);
#endif
if ( ret != NO_ERROR ) {
CAMHAL_LOGEA("Couldn't enable display");
// FIXME: At this stage mStateSwitchLock is locked and unlock is supposed to be called
// only from mCameraAdapter->sendCommand(CameraAdapter::CAMERA_START_PREVIEW)
// below. But this will never happen because of goto error. Thus at next
// startPreview() call CameraHAL will be deadlocked.
// Need to revisit mStateSwitch lock, for now just abort the process.
CAMHAL_ASSERT_X(false,
"At this stage mCameraAdapter->mStateSwitchLock is still locked, "
"deadlock is guaranteed");
goto error;
}
}
///Send START_PREVIEW command to adapter
CAMHAL_LOGDA("Starting CameraAdapter preview mode");
这里调用通过sendCommand实现真正的调用底层开始preview
ret = mCameraAdapter->sendCommand(CameraAdapter::CAMERA_START_PREVIEW);
if(ret!=NO_ERROR) {
CAMHAL_LOGEA("Couldn't start preview w/ CameraAdapter");
goto error;
}
CAMHAL_LOGDA("Started preview");
mPreviewEnabled = true;
mPreviewStartInProgress = false;
return ret;
error:
CAMHAL_LOGEA("Performing cleanup after error");
//Do all the cleanup
freePreviewBufs();
mCameraAdapter->sendCommand(CameraAdapter::CAMERA_STOP_PREVIEW);
if(mDisplayAdapter.get() != NULL) {
mDisplayAdapter->disableDisplay(false);
}
mAppCallbackNotifier->stop();
mPreviewStartInProgress = false;
mPreviewEnabled = false;
LOG_FUNCTION_NAME_EXIT;
return ret;
}
我们现在就重点看看preview开始之前到底都做了哪些初始化吧
/**
@brief Set preview mode related initialization
-> Camera Adapter set params
-> Allocate buffers
-> Set use buffers for preview
@param none
@return NO_ERROR
@todo Update function header with the different errors that are possible
*/
status_t CameraHal::cameraPreviewInitialization()
{
status_t ret = NO_ERROR;
CameraAdapter::BuffersDescriptor desc;
CameraFrame frame;
unsigned int required_buffer_count;
unsigned int max_queueble_buffers;
#if PPM_INSTRUMENTATION || PPM_INSTRUMENTATION_ABS
gettimeofday(&mStartPreview, NULL);
#endif
LOG_FUNCTION_NAME;
if (mPreviewInitializationDone) {
return NO_ERROR;
}
if ( mPreviewEnabled ){
CAMHAL_LOGDA("Preview already running");
LOG_FUNCTION_NAME_EXIT;
return ALREADY_EXISTS;
}
这里首先设置camera使用的基本参数，通过setParameters实现，容易理解
if ( NULL != mCameraAdapter ) {
ret = mCameraAdapter->setParameters(mParameters);
}
/* The first time you startPreview --add by wang,hai-tao*/
这里是我添加的注释，这里这个mPreviewStartInProgress表示camera preview是否正在进行，false则表示不在进行，mDisplayPaused表示camera已经开始显示，只是暂时停止了，这两个状态的检查表明这里是第一次调用preview，初次使用要查询camera匹配的分辨率，所以这里查询获得宽和高，同时保持在外面的全局变量中，以备之后使用
if ((mPreviewStartInProgress == false) && (mDisplayPaused == false)){
ret = mCameraAdapter->sendCommand(CameraAdapter::CAMERA_QUERY_RESOLUTION_PREVIEW,( int ) &frame);
if ( NO_ERROR != ret ){
CAMHAL_LOGEB("Error: CAMERA_QUERY_RESOLUTION_PREVIEW %d", ret);
return ret;
}
///Update the current preview width and height
mPreviewWidth = frame.mWidth;
mPreviewHeight = frame.mHeight;
}
这里我们没有设置preview callback同时也没有使能display adapter，那么我们既没有使用VL4CameraAdapter方式，也没有使用overlay方式，那么OMX方式就是我们唯一的选择了，所以这里让组件进入到Excuting state
///If we don't have the preview callback enabled and display adapter,
if(!mSetPreviewWindowCalled || (mDisplayAdapter.get() == NULL)){
CAMHAL_LOGD("Preview not started. Preview in progress flag set");
mPreviewStartInProgress = true;
ret = mCameraAdapter->sendCommand(CameraAdapter::CAMERA_SWITCH_TO_EXECUTING);
if ( NO_ERROR != ret ){
CAMHAL_LOGEB("Error: CAMERA_SWITCH_TO_EXECUTING %d", ret);
return ret;
}
return NO_ERROR;
}
这里判断我们使用overlay方式，但是这里其实只是暂停了preview，这里做的工作只是从新开启preview，并且开始preview callback
if( (mDisplayAdapter.get() != NULL) && ( !mPreviewEnabled ) && ( mDisplayPaused ) )
{
CAMHAL_LOGDA("Preview is in paused state");
mDisplayPaused = false;
mPreviewEnabled = true;
if ( NO_ERROR == ret )
{
ret = mDisplayAdapter->pauseDisplay(mDisplayPaused);
if ( NO_ERROR != ret )
{
CAMHAL_LOGEB("Display adapter resume failed %x", ret);
}
}
//restart preview callbacks
if(mMsgEnabled & CAMERA_MSG_PREVIEW_FRAME)
{
mAppCallbackNotifier->enableMsgType (CAMERA_MSG_PREVIEW_FRAME);
}
signalEndImageCapture();
return ret;
}
获取到属性中的指定的buffer count
required_buffer_count = atoi(mCameraProperties->get(CameraProperties::REQUIRED_PREVIEW_BUFS));
///Allocate the preview buffers
ret = allocPreviewBufs(mPreviewWidth, mPreviewHeight, mParameters.getPreviewFormat(), required_buffer_count, max_queueble_buffers);
if ( NO_ERROR != ret )
{
CAMHAL_LOGEA("Couldn't allocate buffers for Preview");
goto error;
}
这里其实我一直想不清楚这个MeasurementEnable到底是哪个功能的flag，暂认为是测试数据专用回调吧
if ( mMeasurementEnabled )
{
这里先获取分辨率中的长度
ret = mCameraAdapter->sendCommand(CameraAdapter::CAMERA_QUERY_BUFFER_SIZE_PREVIEW_DATA,
( int ) &frame,
required_buffer_count);
if ( NO_ERROR != ret )
{
return ret;
}
///Allocate the preview data buffers
ret = allocPreviewDataBufs(frame.mLength, required_buffer_count);
if ( NO_ERROR != ret ) {
CAMHAL_LOGEA("Couldn't allocate preview data buffers");
goto error;
}
if ( NO_ERROR == ret )
{
desc.mBuffers = mPreviewDataBuffers;
desc.mOffsets = mPreviewDataOffsets;
desc.mFd = mPreviewDataFd;
desc.mLength = mPreviewDataLength;
desc.mCount = ( size_t ) required_buffer_count;
desc.mMaxQueueable = (size_t) required_buffer_count;
上面通过desc这个变量打包我们的数据，他是BuffersDescriptor类型的变量，也就是buffer属性之类的包，然后调用sendCommand，使用自己申请好的buffer，这里其实是我看这个初始化的重点，当然还有后面的一个sendCommand mCameraAdapter->sendCommand(CameraAdapter::CAMERA_USE_BUFFERS_PREVIEW_DATA,
( int ) &desc);
}
}
///Pass the buffers to Camera Adapter
desc.mBuffers = mPreviewBuffers;
desc.mOffsets = mPreviewOffsets;
desc.mFd = mPreviewFd;
desc.mLength = mPreviewLength;
desc.mCount = ( size_t ) required_buffer_count;
desc.mMaxQueueable = (size_t) max_queueble_buffers;
还有就是这里的这个sendCommand了
ret = mCameraAdapter->sendCommand(CameraAdapter::CAMERA_USE_BUFFERS_PREVIEW,
( int ) &desc);
if ( NO_ERROR != ret )
{
CAMHAL_LOGEB("Failed to register preview buffers: 0x%x", ret);
freePreviewBufs();
return ret;
}
mAppCallbackNotifier->startPreviewCallbacks(mParameters, mPreviewBuffers, mPreviewOffsets, mPreviewFd, mPreviewLength, required_buffer_count);
///Start the callback notifier
ret = mAppCallbackNotifier->start();
if( ALREADY_EXISTS == ret )
{
//Already running, do nothing
CAMHAL_LOGDA("AppCallbackNotifier already running");
ret = NO_ERROR;
}
else if ( NO_ERROR == ret ) {
CAMHAL_LOGDA("Started AppCallbackNotifier..");
mAppCallbackNotifier->setMeasurements(mMeasurementEnabled);
}
else
{
CAMHAL_LOGDA("Couldn't start AppCallbackNotifier");
goto error;
}
if (ret == NO_ERROR) mPreviewInitializationDone = true;
return ret;
error:
CAMHAL_LOGEA("Performing cleanup after error");
//Do all the cleanup
freePreviewBufs();
mCameraAdapter->sendCommand(CameraAdapter::CAMERA_STOP_PREVIEW);
if(mDisplayAdapter.get() != NULL)
{
mDisplayAdapter->disableDisplay(false);
}
mAppCallbackNotifier->stop();
mPreviewStartInProgress = false;
mPreviewEnabled = false;
LOG_FUNCTION_NAME_EXIT;
return ret;
}
这里我们还是分析一下下面这个方法的实现
ret = mCameraAdapter->sendCommand(CameraAdapter::CAMERA_SWITCH_TO_EXECUTING);
这个调用最终调用到BaseCameraAdapter下的sendCommand然后调用到OMXCameraAdapter下的方法switchToExecuting，这个方法的实现在下面
status_t OMXCameraAdapter::switchToExecuting()
{
status_t ret = NO_ERROR;
TIUTILS::Message msg;
LOG_FUNCTION_NAME;
mStateSwitchLock.lock();
msg.command = CommandHandler::CAMERA_SWITCH_TO_EXECUTING;
msg.arg1 = mErrorNotifier;
ret = mCommandHandler->put(&msg);
LOG_FUNCTION_NAME_EXIT;
return ret;
}
这个方法只是给mCommandHandler发送了一个消息，这个消息告诉CommandHandler处理CAMERA_SWITCH_TO_EXECUTING这条命令而已，我们看看mCommandHandler中的handle是怎么处理我们的命令的
case CommandHandler::CAMERA_SWITCH_TO_EXECUTING:
{
stat = mCameraAdapter->doSwitchToExecuting();
break;
}
我们看看这个方法的实现
status_t OMXCameraAdapter::doSwitchToExecuting()
{
status_t ret = NO_ERROR;
OMX_ERRORTYPE eError = OMX_ErrorNone;
LOG_FUNCTION_NAME;
if ( (mComponentState == OMX_StateExecuting) || (mComponentState == OMX_StateInvalid) ){
CAMHAL_LOGDA("Already in OMX_Executing state or OMX_StateInvalid state");
mStateSwitchLock.unlock();
return NO_ERROR;
}
if ( 0 != mSwitchToExecSem.Count() ){
CAMHAL_LOGEB("Error mSwitchToExecSem semaphore count %d", mSwitchToExecSem.Count());
goto EXIT;
}
///Register for Preview port DISABLE event
ret = RegisterForEvent(mCameraAdapterParameters.mHandleComp,
OMX_EventCmdComplete,
OMX_CommandPortDisable,
mCameraAdapterParameters.mPrevPortIndex,
mSwitchToExecSem);
if ( NO_ERROR != ret ){
CAMHAL_LOGEB("Error in registering Port Disable for event %d", ret);
goto EXIT;
}
///Disable Preview Port
eError = OMX_SendCommand(mCameraAdapterParameters.mHandleComp,
OMX_CommandPortDisable,
mCameraAdapterParameters.mPrevPortIndex,
NULL);
ret = mSwitchToExecSem.WaitTimeout(OMX_CMD_TIMEOUT);
if (ret != NO_ERROR){
CAMHAL_LOGEB("Timeout PREVIEW PORT DISABLE %d", ret);
}
CAMHAL_LOGVB("PREV PORT DISABLED %d", ret);
///Register for IDLE state switch event
ret = RegisterForEvent(mCameraAdapterParameters.mHandleComp,
OMX_EventCmdComplete,
OMX_CommandStateSet,
OMX_StateIdle,
mSwitchToExecSem);
if(ret!=NO_ERROR)
{
CAMHAL_LOGEB("Error in IDLE STATE SWITCH %d", ret);
goto EXIT;
}
eError = OMX_SendCommand (mCameraAdapterParameters.mHandleComp ,
OMX_CommandStateSet,
OMX_StateIdle,
NULL);
GOTO_EXIT_IF((eError!=OMX_ErrorNone), eError);
ret = mSwitchToExecSem.WaitTimeout(OMX_CMD_TIMEOUT);
if (ret != NO_ERROR){
CAMHAL_LOGEB("Timeout IDLE STATE SWITCH %d", ret);
goto EXIT;
}
mComponentState = OMX_StateIdle;
CAMHAL_LOGVB("OMX_SendCommand(OMX_StateIdle) 0x%x", eError);
///Register for EXECUTING state switch event
ret = RegisterForEvent(mCameraAdapterParameters.mHandleComp,
OMX_EventCmdComplete,
OMX_CommandStateSet,
OMX_StateExecuting,
mSwitchToExecSem);
if(ret!=NO_ERROR)
{
CAMHAL_LOGEB("Error in EXECUTING STATE SWITCH %d", ret);
goto EXIT;
}
eError = OMX_SendCommand (mCameraAdapterParameters.mHandleComp ,
OMX_CommandStateSet,
OMX_StateExecuting,
NULL);
GOTO_EXIT_IF((eError!=OMX_ErrorNone), eError);
ret = mSwitchToExecSem.WaitTimeout(OMX_CMD_TIMEOUT);
if (ret != NO_ERROR){
CAMHAL_LOGEB("Timeout EXEC STATE SWITCH %d", ret);
goto EXIT;
}
mComponentState = OMX_StateExecuting;
CAMHAL_LOGVB("OMX_SendCommand(OMX_StateExecuting) 0x%x", eError);
mStateSwitchLock.unlock();
LOG_FUNCTION_NAME_EXIT;
return ret;
EXIT:
CAMHAL_LOGEB("Exiting function %s because of ret %d eError=%x", __FUNCTION__, ret, eError);
performCleanupAfterError();
mStateSwitchLock.unlock();
LOG_FUNCTION_NAME_EXIT;
return (ret | ErrorUtils::omxToAndroidError(eError));
}
上面一连串做了三件事情：
1、 disable preview port，注册事件处理通知，等待组件返回处理通知
2、 转换状态到IDLE STATE，注册事件处理通知，等待组件返回处理通知
3、 转换状态到EXCUTING STATE，注册事件处理通知，等待组件返回处理通知
接下来重点看一下，我们自己申请了buffer，看看怎么通知底层使用我们的buffer而不要从新申请buffer，这个调用最会调用到底层的useBuffer方法，直接看看这个方法的实现吧
///API to give the buffers to Adapter这注释说的很清楚了
status_t OMXCameraAdapter::useBuffers(CameraMode mode, CameraBuffer * bufArr, int num, size_t length, unsigned int queueable)
{
OMX_ERRORTYPE eError = OMX_ErrorNone;
status_t ret = NO_ERROR;
LOG_FUNCTION_NAME;
switch(mode)
{
case CAMERA_PREVIEW:
mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mPrevPortIndex].mNumBufs = num;
mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mPrevPortIndex].mMaxQueueable = queueable;
ret = UseBuffersPreview(bufArr, num);
break;
case CAMERA_IMAGE_CAPTURE:
mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mImagePortIndex].mNumBufs = num;
mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mImagePortIndex].mMaxQueueable = queueable;
ret = UseBuffersCapture(bufArr, num);
break;
case CAMERA_VIDEO:
mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mVideoPortIndex].mNumBufs = num;
mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mVideoPortIndex].mMaxQueueable = queueable;
ret = UseBuffersRawCapture(bufArr, num);
break;
case CAMERA_MEASUREMENT:
mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mMeasurementPortIndex].mNumBufs = num;
mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mMeasurementPortIndex].mMaxQueueable = queueable;
ret = UseBuffersPreviewData(bufArr, num);
break;
case CAMERA_REPROCESS:
mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mVideoInPortIndex].mNumBufs = num;
mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mVideoInPortIndex].mMaxQueueable = queueable;
ret = UseBuffersReprocess(bufArr, num);
break;
}
LOG_FUNCTION_NAME_EXIT;
return ret;
}
这个看看UseBufferPreview这个方法
status_t OMXCameraAdapter::UseBuffersPreview(CameraBuffer * bufArr, int num)
{
status_t ret = NO_ERROR;
OMX_ERRORTYPE eError = OMX_ErrorNone;
int tmpHeight, tmpWidth;
LOG_FUNCTION_NAME;
if(!bufArr)
{
CAMHAL_LOGEA("NULL pointer passed for buffArr");
LOG_FUNCTION_NAME_EXIT;
return BAD_VALUE;
}
OMXCameraPortParameters * mPreviewData = NULL;
OMXCameraPortParameters *measurementData = NULL;
mPreviewData = &mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mPrevPortIndex];
measurementData = &mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mMeasurementPortIndex];
mPreviewData->mNumBufs = num ;
if ( 0 != mUsePreviewSem.Count() )
{
CAMHAL_LOGEB("Error mUsePreviewSem semaphore count %d", mUsePreviewSem.Count());
LOG_FUNCTION_NAME_EXIT;
return NO_INIT;
}
if(mPreviewData->mNumBufs != num)
{
CAMHAL_LOGEA("Current number of buffers doesnt equal new num of buffers passed!");
LOG_FUNCTION_NAME_EXIT;
return BAD_VALUE;
}
mStateSwitchLock.lock();
这里其实我不是很理解下面这些方法都干了些什么，不过不重要，暂且跳过
if ( mComponentState == OMX_StateLoaded ) {
if (mPendingPreviewSettings & SetLDC) {
mPendingPreviewSettings &= ~SetLDC;
ret = setLDC(mIPP);
if ( NO_ERROR != ret ) {
CAMHAL_LOGEB("setLDC() failed %d", ret);
}
}
if (mPendingPreviewSettings & SetNSF) {
mPendingPreviewSettings &= ~SetNSF;
ret = setNSF(mIPP);
if ( NO_ERROR != ret ) {
CAMHAL_LOGEB("setNSF() failed %d", ret);
}
}
if (mPendingPreviewSettings & SetCapMode) {
mPendingPreviewSettings &= ~SetCapMode;
ret = setCaptureMode(mCapMode);
if ( NO_ERROR != ret ) {
CAMHAL_LOGEB("setCaptureMode() failed %d", ret);
}
}
if(mCapMode == OMXCameraAdapter::VIDEO_MODE) {
if (mPendingPreviewSettings & SetVNF) {
mPendingPreviewSettings &= ~SetVNF;
ret = enableVideoNoiseFilter(mVnfEnabled);
if ( NO_ERROR != ret){
CAMHAL_LOGEB("Error configuring VNF %x", ret);
}
}
if (mPendingPreviewSettings & SetVSTAB) {
mPendingPreviewSettings &= ~SetVSTAB;
ret = enableVideoStabilization(mVstabEnabled);
if ( NO_ERROR != ret) {
CAMHAL_LOGEB("Error configuring VSTAB %x", ret);
}
}
}
}
ret = setSensorOrientation(mSensorOrientation);
if ( NO_ERROR != ret )
{
CAMHAL_LOGEB("Error configuring Sensor Orientation %x", ret);
mSensorOrientation = 0;
}
if ( mComponentState == OMX_StateLoaded )
{
///Register for IDLE state switch event
ret = RegisterForEvent(mCameraAdapterParameters.mHandleComp,
OMX_EventCmdComplete,
OMX_CommandStateSet,
OMX_StateIdle,
mUsePreviewSem);
if(ret!=NO_ERROR)
{
CAMHAL_LOGEB("Error in registering for event %d", ret);
goto EXIT;
}
///Once we get the buffers, move component state to idle state and pass the buffers to OMX comp using UseBuffer
eError = OMX_SendCommand (mCameraAdapterParameters.mHandleComp ,
OMX_CommandStateSet,
OMX_StateIdle,
NULL);
CAMHAL_LOGDB("OMX_SendCommand(OMX_CommandStateSet) 0x%x", eError);
GOTO_EXIT_IF((eError!=OMX_ErrorNone), eError);
mComponentState = OMX_StateIdle;
}
else
{
///Register for Preview port ENABLE event
ret = RegisterForEvent(mCameraAdapterParameters.mHandleComp,
OMX_EventCmdComplete,
OMX_CommandPortEnable,
mCameraAdapterParameters.mPrevPortIndex,
mUsePreviewSem);
if ( NO_ERROR != ret )
{
CAMHAL_LOGEB("Error in registering for event %d", ret);
goto EXIT;
}
///Enable Preview Port
eError = OMX_SendCommand(mCameraAdapterParameters.mHandleComp,
OMX_CommandPortEnable,
mCameraAdapterParameters.mPrevPortIndex,
NULL);
}
///Configure DOMX to use either gralloc handles or vptrs
OMX_TI_PARAMUSENATIVEBUFFER domxUseGrallocHandles;
OMX_INIT_STRUCT_PTR (&domxUseGrallocHandles, OMX_TI_PARAMUSENATIVEBUFFER);
domxUseGrallocHandles.nPortIndex = mCameraAdapterParameters.mPrevPortIndex;
domxUseGrallocHandles.bEnable = OMX_TRUE;
eError = OMX_SetParameter(mCameraAdapterParameters.mHandleComp,
(OMX_INDEXTYPE)OMX_TI_IndexUseNativeBuffers, &domxUseGrallocHandles);
if(eError!=OMX_ErrorNone)
{
CAMHAL_LOGEB("OMX_SetParameter - %x", eError);
}
GOTO_EXIT_IF((eError!=OMX_ErrorNone), eError);
OMX_BUFFERHEADERTYPE *pBufferHdr;
for(int index=0;index<num;index++) {
OMX_U8 *ptr;
ptr = (OMX_U8 *)camera_buffer_get_omx_ptr (&bufArr[index]);
eError = OMX_UseBuffer( mCameraAdapterParameters.mHandleComp,
&pBufferHdr,
mCameraAdapterParameters.mPrevPortIndex,
0,
mPreviewData->mBufSize,
ptr);
if(eError!=OMX_ErrorNone)
{
CAMHAL_LOGEB("OMX_UseBuffer-0x%x", eError);
}
GOTO_EXIT_IF((eError!=OMX_ErrorNone), eError);
pBufferHdr->pAppPrivate = (OMX_PTR)&bufArr[index];
pBufferHdr->nSize = sizeof(OMX_BUFFERHEADERTYPE);
pBufferHdr->nVersion.s.nVersionMajor = 1 ;
pBufferHdr->nVersion.s.nVersionMinor = 1 ;
pBufferHdr->nVersion.s.nRevision = 0 ;
pBufferHdr->nVersion.s.nStep = 0;
mPreviewData->mBufferHeader[index] = pBufferHdr;
}
if ( mMeasurementEnabled )
{
for( int i = 0; i < num; i++ )
{
OMX_BUFFERHEADERTYPE *pBufHdr;
OMX_U8 *ptr;
ptr = (OMX_U8 *)camera_buffer_get_omx_ptr (&mPreviewDataBuffers[i]);
eError = OMX_UseBuffer( mCameraAdapterParameters.mHandleComp,
&pBufHdr,
mCameraAdapterParameters.mMeasurementPortIndex,
0,
measurementData->mBufSize,
ptr);
if ( eError == OMX_ErrorNone )
{
pBufHdr->pAppPrivate = (OMX_PTR *)&mPreviewDataBuffers[i];
pBufHdr->nSize = sizeof(OMX_BUFFERHEADERTYPE);
pBufHdr->nVersion.s.nVersionMajor = 1 ;
pBufHdr->nVersion.s.nVersionMinor = 1 ;
pBufHdr->nVersion.s.nRevision = 0 ;
pBufHdr->nVersion.s.nStep = 0;
measurementData->mBufferHeader[i] = pBufHdr;
}
else
{
CAMHAL_LOGEB("OMX_UseBuffer -0x%x", eError);
ret = BAD_VALUE;
break;
}
}
}
CAMHAL_LOGDA("Registering preview buffers");
ret = mUsePreviewSem.WaitTimeout(OMX_CMD_TIMEOUT);
//If somethiing bad happened while we wait
if (mComponentState == OMX_StateInvalid)
{
CAMHAL_LOGEA("Invalid State after Registering preview buffers Exitting!!!");
goto EXIT;
}
if ( NO_ERROR == ret )
{
CAMHAL_LOGDA("Preview buffer registration successfull");
}
else
{
if ( mComponentState == OMX_StateLoaded )
{
ret |= RemoveEvent(mCameraAdapterParameters.mHandleComp,
OMX_EventCmdComplete,
OMX_CommandStateSet,
OMX_StateIdle,
NULL);
}
else
{
ret |= SignalEvent(mCameraAdapterParameters.mHandleComp,
OMX_EventCmdComplete,
OMX_CommandPortEnable,
mCameraAdapterParameters.mPrevPortIndex,
NULL);
}
CAMHAL_LOGEA("Timeout expired on preview buffer registration");
goto EXIT;
}
LOG_FUNCTION_NAME_EXIT;
return (ret | ErrorUtils::omxToAndroidError(eError));
///If there is any failure, we reach here.
///Here, we do any resource freeing and convert from OMX error code to Camera Hal error code
EXIT:
mStateSwitchLock.unlock();
CAMHAL_LOGEB("Exiting function %s because of ret %d eError=%x", __FUNCTION__, ret, eError);
performCleanupAfterError();
CAMHAL_LOGEB("Exiting function %s because of ret %d eError=%x", __FUNCTION__, ret, eError);
LOG_FUNCTION_NAME_EXIT;
return (ret | ErrorUtils::omxToAndroidError(eError));
}
最后这里还是很有必要看一下调用的startPreviewCallback方法
status_t AppCallbackNotifier::startPreviewCallbacks(CameraParameters ¶ms, CameraBuffer *buffers, uint32_t *offsets, int fd, size_t length, size_t count)
{
sp<MemoryHeapBase> heap;
sp<MemoryBase> buffer;
unsigned int *bufArr;
int size = 0;
LOG_FUNCTION_NAME;
Mutex::Autolock lock(mLock);
if ( NULL == mFrameProvider )
{
CAMHAL_LOGEA("Trying to start video recording without FrameProvider");
return -EINVAL;
}
if ( mPreviewing )
{
CAMHAL_LOGDA("+Already previewing");
return NO_INIT;
}
int w,h;
///Get preview size
params.getPreviewSize(&w, &h);
// save preview pixel format, size and stride
mPreviewWidth = w;
mPreviewHeight = h;
mPreviewStride = 4096;
mPreviewPixelFormat = getContstantForPixelFormat(params.getPreviewFormat());
size = calculateBufferSize(w, h, mPreviewPixelFormat);
这里根据传入的尺寸信息申请memory，
mPreviewMemory = mRequestMemory(-1, size, AppCallbackNotifier::MAX_BUFFERS, NULL);
if (!mPreviewMemory) {
return NO_MEMORY;
}
for (int i=0; i < AppCallbackNotifier::MAX_BUFFERS; i++) {
mPreviewBuffers[i].type = CAMERA_BUFFER_MEMORY;
mPreviewBuffers[i].opaque = (unsigned char*) mPreviewMemory->data + (i*size);
mPreviewBuffers[i].mapped = mPreviewBuffers[i].opaque;
}
if ( mCameraHal->msgTypeEnabled(CAMERA_MSG_PREVIEW_FRAME ) ) {
mFrameProvider->enableFrameNotification(CameraFrame::PREVIEW_FRAME_SYNC);
}
if ( mCameraHal->msgTypeEnabled(CAMERA_MSG_POSTVIEW_FRAME) ) {
mFrameProvider->enableFrameNotification(CameraFrame::SNAPSHOT_FRAME);
}
mPreviewBufCount = 0;
mPreviewing = true;
LOG_FUNCTION_NAME_EXIT;
return NO_ERROR;
}
到这里startPreview的初始化过程就结束了，下面咱们就进到底层看看OMXCameraAdapter是怎样实现开始preview的
status_t OMXCameraAdapter::startPreview()
{
status_t ret = NO_ERROR;
OMX_ERRORTYPE eError = OMX_ErrorNone;
OMXCameraPortParameters *mPreviewData = NULL;
OMXCameraPortParameters *measurementData = NULL;
LOG_FUNCTION_NAME;
if( 0 != mStartPreviewSem.Count() )
{
CAMHAL_LOGEB("Error mStartPreviewSem semaphore count %d", mStartPreviewSem.Count());
ret = NO_INIT;
goto EXIT;
}
// Enable all preview mode extra data.
if ( OMX_ErrorNone == eError) {
ret |= setExtraData(true, mCameraAdapterParameters.mPrevPortIndex, OMX_AncillaryData);
ret |= setExtraData(true, OMX_ALL, OMX_TI_VectShotInfo);
}
mPreviewData = &mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mPrevPortIndex];
measurementData = &mCameraAdapterParameters.mCameraPortParams[mCameraAdapterParameters.mMeasurementPortIndex];
if( OMX_StateIdle == mComponentState )
{
///Register for EXECUTING state transition.
///This method just inserts a message in Event Q, which is checked in the callback
///The sempahore passed is signalled by the callback
ret = RegisterForEvent(mCameraAdapterParameters.mHandleComp,
OMX_EventCmdComplete,
OMX_CommandStateSet,
OMX_StateExecuting,
mStartPreviewSem);
if(ret!=NO_ERROR)
{
CAMHAL_LOGEB("Error in registering for event %d", ret);
goto EXIT;
}
///Switch to EXECUTING state
eError = OMX_SendCommand(mCameraAdapterParameters.mHandleComp,
OMX_CommandStateSet,
OMX_StateExecuting,
NULL);
if(eError!=OMX_ErrorNone)
{
CAMHAL_LOGEB("OMX_SendCommand(OMX_StateExecuting)-0x%x", eError);
}
CAMHAL_LOGDA("+Waiting for component to go into EXECUTING state");
ret = mStartPreviewSem.WaitTimeout(OMX_CMD_TIMEOUT);
//If somethiing bad happened while we wait
if (mComponentState == OMX_StateInvalid)
{
CAMHAL_LOGEA("Invalid State after IDLE_EXECUTING Exitting!!!");
goto EXIT;
}
if ( NO_ERROR == ret )
{
CAMHAL_LOGDA("+Great. Component went into executing state!!");
}
else
{
ret |= RemoveEvent(mCameraAdapterParameters.mHandleComp,
OMX_EventCmdComplete,
OMX_CommandStateSet,
OMX_StateExecuting,
NULL);
CAMHAL_LOGDA("Timeout expired on executing state switch!");
goto EXIT;
}
mComponentState = OMX_StateExecuting;
}
mStateSwitchLock.unlock();
//Queue all the buffers on preview port
for(int index=0;index< mPreviewData->mMaxQueueable;index++)
{
CAMHAL_LOGDB("Queuing buffer on Preview port - 0x%x", (uint32_t)mPreviewData->mBufferHeader[index]->pBuffer);
mPreviewData->mStatus[index] = OMXCameraPortParameters::FILL;
eError = OMX_FillThisBuffer(mCameraAdapterParameters.mHandleComp,
(OMX_BUFFERHEADERTYPE*)mPreviewData->mBufferHeader[index]);
if(eError!=OMX_ErrorNone)
{
CAMHAL_LOGEB("OMX_FillThisBuffer-0x%x", eError);
}
mFramesWithDucati++;
#ifdef CAMERAHAL_DEBUG
mBuffersWithDucati.add((int)mPreviewData->mBufferHeader[index]->pAppPrivate,1);
#endif
GOTO_EXIT_IF((eError!=OMX_ErrorNone), eError);
}
if ( mMeasurementEnabled )
{
for(int index=0;index< mPreviewData->mNumBufs;index++)
{
CAMHAL_LOGDB("Queuing buffer on Measurement port - 0x%x", (uint32_t) measurementData->mBufferHeader[index]->pBuffer);
measurementData->mStatus[index] = OMXCameraPortParameters::FILL;
eError = OMX_FillThisBuffer(mCameraAdapterParameters.mHandleComp,
(OMX_BUFFERHEADERTYPE*) measurementData->mBufferHeader[index]);
if(eError!=OMX_ErrorNone)
{
CAMHAL_LOGEB("OMX_FillThisBuffer-0x%x", eError);
}
GOTO_EXIT_IF((eError!=OMX_ErrorNone), eError);
}
}
setFocusCallback(true);
//reset frame rate estimates
mFPS = 0.0f;
mLastFPS = 0.0f;
// start frame count from 0. i.e first frame after
// startPreview will be the 0th reference frame
// this way we will wait for second frame until
// takePicture/autoFocus is allowed to run. we
// are seeing SetConfig/GetConfig fail after
// calling after the first frame and not failing
// after the second frame
mFrameCount = -1;
mLastFrameCount = 0;
mIter = 1;
mLastFPSTime = systemTime();
mTunnelDestroyed = false;
LOG_FUNCTION_NAME_EXIT;
return (ret | ErrorUtils::omxToAndroidError(eError));
EXIT:
CAMHAL_LOGEB("Exiting function %s because of ret %d eError=%x", __FUNCTION__, ret, eError);
performCleanupAfterError();
mStateSwitchLock.unlock();
LOG_FUNCTION_NAME_EXIT;
return (ret | ErrorUtils::omxToAndroidError(eError));
}
其实底层的这个方法实现的方法比我想象的要简单，这里不做过多的说明，上面只是首先保证组件处于Excting state，然后调用OMX_FillBuffer方法把所有的buffer 加入到组件中接收编码好的buffer，fillBuffer完成后，会通过FillBufferDone这个回调，通知应用层，包括把buffer给到应用从，这里不做过多说明，直接看看fillBufferDone是怎么处理的吧
/*========================================================*/
/* @ fn SampleTest_FillBufferDone :: Application callback*/
/*========================================================*/
OMX_ERRORTYPE OMXCameraAdapterFillBufferDone(OMX_IN OMX_HANDLETYPE hComponent,
OMX_IN OMX_PTR pAppData,
OMX_IN OMX_BUFFERHEADERTYPE* pBuffHeader)
{
TIUTILS::Message msg;
OMX_ERRORTYPE eError = OMX_ErrorNone;
if (UNLIKELY(mDebugFps)) {
debugShowFPS();
}
OMXCameraAdapter *adapter = ( OMXCameraAdapter * ) pAppData;
if ( NULL != adapter )
{
msg.command = OMXCameraAdapter::OMXCallbackHandler::CAMERA_FILL_BUFFER_DONE;
msg.arg1 = ( void * ) hComponent;
msg.arg2 = ( void * ) pBuffHeader;
adapter->mOMXCallbackHandler->put(&msg);
}
return eError;
}
这里只是打包消息，并发送消息最终是由OMXCallbackHandler中的handle去处理这个消息的
bool OMXCameraAdapter::OMXCallbackHandler::Handler()
{
TIUTILS::Message msg;
volatile int forever = 1;
status_t ret = NO_ERROR;
LOG_FUNCTION_NAME;
while(forever){
TIUTILS::MessageQueue::waitForMsg(&mCommandMsgQ, NULL, NULL, -1);
{检查到消息，接着往下走
Mutex::Autolock lock(mLock);
mCommandMsgQ.get(&msg);
mIsProcessed = false;
}
switch ( msg.command ) {
case OMXCallbackHandler::CAMERA_FILL_BUFFER_DONE:
{
ret = mCameraAdapter->OMXCameraAdapterFillBufferDone(( OMX_HANDLETYPE ) msg.arg1,
( OMX_BUFFERHEADERTYPE *) msg.arg2);
break;
}
case OMXCallbackHandler::CAMERA_FOCUS_STATUS:
{
mCameraAdapter->handleFocusCallback();
break;
}
case CommandHandler::COMMAND_EXIT:
{
CAMHAL_LOGDA("Exiting OMX callback handler");
forever = 0;
break;
}
}
{
android::AutoMutex locker(mLock);
CAMHAL_UNUSED(locker);
mIsProcessed = mCommandMsgQ.isEmpty();
if ( mIsProcessed )
mCondition.signal();
}
}
// force the condition to wake
{
android::AutoMutex locker(mLock);
CAMHAL_UNUSED(locker);
mIsProcessed = true;
mCondition.signal();
}
LOG_FUNCTION_NAME_EXIT;
return false;
}
检查到fillBufferDone消息，调用OMXCameraAdapter下的fillBufferDone处理方法
#endif
/*========================================================*/
/* @ fn SampleTest_FillBufferDone :: Application callback*/
/*========================================================*/
OMX_ERRORTYPE OMXCameraAdapter::OMXCameraAdapterFillBufferDone(OMX_IN OMX_HANDLETYPE hComponent,
OMX_IN OMX_BUFFERHEADERTYPE* pBuffHeader)
{
status_t stat = NO_ERROR;
status_t res1, res2;
OMXCameraPortParameters *pPortParam;
OMX_ERRORTYPE eError = OMX_ErrorNone;
CameraFrame::FrameType typeOfFrame = CameraFrame::ALL_FRAMES;
unsigned int refCount = 0;
BaseCameraAdapter::AdapterState state, nextState;
BaseCameraAdapter::getState(state);
BaseCameraAdapter::getNextState(nextState);
sp<CameraMetadataResult> metadataResult = NULL;
unsigned int mask = 0xFFFF;
CameraFrame cameraFrame;
OMX_OTHER_EXTRADATATYPE *extraData;
OMX_TI_ANCILLARYDATATYPE *ancillaryData = NULL;
bool snapshotFrame = false;
if ( NULL == pBuffHeader ) {
return OMX_ErrorBadParameter;
}
#ifdef CAMERAHAL_OMX_PROFILING
storeProfilingData(pBuffHeader);
#endif
res1 = res2 = NO_ERROR;
if ( !pBuffHeader || !pBuffHeader->pBuffer ) {
CAMHAL_LOGEA("NULL Buffer from OMX");
return OMX_ErrorNone;
}
pPortParam = &(mCameraAdapterParameters.mCameraPortParams[pBuffHeader->nOutputPortIndex]);
// Find buffer and mark it as filled
for (int i = 0; i < pPortParam->mNumBufs; i++) {
if (pPortParam->mBufferHeader[i] == pBuffHeader) {
pPortParam->mStatus[i] = OMXCameraPortParameters::DONE;
}
}
if (pBuffHeader->nOutputPortIndex == OMX_CAMERA_PORT_VIDEO_OUT_PREVIEW)
{
if ( ( PREVIEW_ACTIVE & state ) != PREVIEW_ACTIVE )
{
return OMX_ErrorNone;
}
if ( mWaitingForSnapshot ) {
extraData = getExtradata(pBuffHeader->pPlatformPrivate,
(OMX_EXTRADATATYPE) OMX_AncillaryData);
if ( NULL != extraData ) {
ancillaryData = (OMX_TI_ANCILLARYDATATYPE*) extraData->data;
if ((OMX_2D_Snap == ancillaryData->eCameraView)
|| (OMX_3D_Left_Snap == ancillaryData->eCameraView)
|| (OMX_3D_Right_Snap == ancillaryData->eCameraView)) {
snapshotFrame = OMX_TRUE;
} else {
snapshotFrame = OMX_FALSE;
}
mPending3Asettings |= SetFocus;
}
}
///Prepare the frames to be sent - initialize CameraFrame object and reference count
// TODO(XXX): ancillary data for snapshot frame is not being sent for video snapshot
// if we are waiting for a snapshot and in video mode...go ahead and send
// this frame as a snapshot
if( mWaitingForSnapshot && (mCapturedFrames > 0) &&
(snapshotFrame || (mCapMode == VIDEO_MODE)))
{
typeOfFrame = CameraFrame::SNAPSHOT_FRAME;
mask = (unsigned int)CameraFrame::SNAPSHOT_FRAME;
// video snapshot gets ancillary data and wb info from last snapshot frame
mCaptureAncillaryData = ancillaryData;
mWhiteBalanceData = NULL;
extraData = getExtradata(pBuffHeader->pPlatformPrivate,
(OMX_EXTRADATATYPE) OMX_WhiteBalance);
if ( NULL != extraData )
{
mWhiteBalanceData = (OMX_TI_WHITEBALANCERESULTTYPE*) extraData->data;
}
}
else
{
typeOfFrame = CameraFrame::PREVIEW_FRAME_SYNC;
mask = (unsigned int)CameraFrame::PREVIEW_FRAME_SYNC;
}
if (mRecording)
{
mask |= (unsigned int)CameraFrame::VIDEO_FRAME_SYNC;
mFramesWithEncoder++;
}
//LOGV("FBD pBuffer = 0x%x", pBuffHeader->pBuffer);
if( mWaitingForSnapshot )
{
if (!mBracketingEnabled &&
((HIGH_SPEED == mCapMode) || (VIDEO_MODE == mCapMode)) )
{
notifyShutterSubscribers();
}
}
stat = sendCallBacks(cameraFrame, pBuffHeader, mask, pPortParam);
mFramesWithDisplay++;
mFramesWithDucati--;
#ifdef CAMERAHAL_DEBUG
if(mBuffersWithDucati.indexOfKey((uint32_t)pBuffHeader->pBuffer)<0)
{
LOGE("Buffer was never with Ducati!! %p", pBuffHeader->pBuffer);
for(unsigned int i=0;i<mBuffersWithDucati.size();i++) LOGE("0x%x", mBuffersWithDucati.keyAt(i));
}
mBuffersWithDucati.removeItem((int)pBuffHeader->pBuffer);
#endif
if(mDebugFcs)
CAMHAL_LOGEB("C[%d] D[%d] E[%d]", mFramesWithDucati, mFramesWithDisplay, mFramesWithEncoder);
recalculateFPS();
createPreviewMetadata(pBuffHeader, metadataResult, pPortParam->mWidth, pPortParam->mHeight);
if ( NULL != metadataResult.get() ) {
notifyMetadataSubscribers(metadataResult);
metadataResult.clear();
}
{
Mutex::Autolock lock(mFaceDetectionLock);
if ( mFDSwitchAlgoPriority ) {
//Disable region priority and enable face priority for AF
setAlgoPriority(REGION_PRIORITY, FOCUS_ALGO, false);
setAlgoPriority(FACE_PRIORITY, FOCUS_ALGO , true);
//Disable Region priority and enable Face priority
setAlgoPriority(REGION_PRIORITY, EXPOSURE_ALGO, false);
setAlgoPriority(FACE_PRIORITY, EXPOSURE_ALGO, true);
mFDSwitchAlgoPriority = false;
}
}
sniffDccFileDataSave(pBuffHeader);
stat |= advanceZoom();
// On the fly update to 3A settings not working
// Do not update 3A here if we are in the middle of a capture
// or in the middle of transitioning to it
if( mPending3Asettings &&
( (nextState & CAPTURE_ACTIVE) == 0 ) &&
( (state & CAPTURE_ACTIVE) == 0 ) ) {
apply3Asettings(mParameters3A);
}
}
else if( pBuffHeader->nOutputPortIndex == OMX_CAMERA_PORT_VIDEO_OUT_MEASUREMENT )
{
typeOfFrame = CameraFrame::FRAME_DATA_SYNC;
mask = (unsigned int)CameraFrame::FRAME_DATA_SYNC;
stat = sendCallBacks(cameraFrame, pBuffHeader, mask, pPortParam);
}
else if( pBuffHeader->nOutputPortIndex == OMX_CAMERA_PORT_IMAGE_OUT_IMAGE )
{
OMX_COLOR_FORMATTYPE pixFormat;
const char *valstr = NULL;
pixFormat = pPortParam->mColorFormat;
if ( OMX_COLOR_FormatUnused == pixFormat )
{
typeOfFrame = CameraFrame::IMAGE_FRAME;
mask = (unsigned int) CameraFrame::IMAGE_FRAME;
} else if ( pixFormat == OMX_COLOR_FormatCbYCrY &&
((mPictureFormatFromClient &&
!strcmp(mPictureFormatFromClient,
CameraParameters::PIXEL_FORMAT_JPEG)) ||
!mPictureFormatFromClient) ) {
// signals to callbacks that this needs to be coverted to jpeg
// before returning to framework
typeOfFrame = CameraFrame::IMAGE_FRAME;
mask = (unsigned int) CameraFrame::IMAGE_FRAME;
cameraFrame.mQuirks |= CameraFrame::ENCODE_RAW_YUV422I_TO_JPEG;
cameraFrame.mQuirks |= CameraFrame::FORMAT_YUV422I_UYVY;
// populate exif data and pass to subscribers via quirk
// subscriber is in charge of freeing exif data
ExifElementsTable* exif = new ExifElementsTable();
setupEXIF_libjpeg(exif, mCaptureAncillaryData, mWhiteBalanceData);
cameraFrame.mQuirks |= CameraFrame::HAS_EXIF_DATA;
cameraFrame.mCookie2 = (void*) exif;
} else {
typeOfFrame = CameraFrame::RAW_FRAME;
mask = (unsigned int) CameraFrame::RAW_FRAME;
}
pPortParam->mImageType = typeOfFrame;
if((mCapturedFrames>0) && !mCaptureSignalled)
{
mCaptureSignalled = true;
mCaptureSem.Signal();
}
if( ( CAPTURE_ACTIVE & state ) != CAPTURE_ACTIVE )
{
goto EXIT;
}
{
Mutex::Autolock lock(mBracketingLock);
if ( mBracketingEnabled )
{
doBracketing(pBuffHeader, typeOfFrame);
return eError;
}
}
if (mZoomBracketingEnabled) {
doZoom(mZoomBracketingValues[mCurrentZoomBracketing]);
CAMHAL_LOGDB("Current Zoom Bracketing: %d", mZoomBracketingValues[mCurrentZoomBracketing]);
mCurrentZoomBracketing++;
if (mCurrentZoomBracketing == ARRAY_SIZE(mZoomBracketingValues)) {
mZoomBracketingEnabled = false;
}
}
if ( 1 > mCapturedFrames )
{
goto EXIT;
}
#ifdef OMAP_ENHANCEMENT_CPCAM
setMetaData(cameraFrame.mMetaData, pBuffHeader->pPlatformPrivate);
#endif
CAMHAL_LOGDB("Captured Frames: %d", mCapturedFrames);
mCapturedFrames--;
#ifdef CAMERAHAL_USE_RAW_IMAGE_SAVING
if (mYuvCapture) {
struct timeval timeStampUsec;
gettimeofday(&timeStampUsec, NULL);
time_t saveTime;
time(&saveTime);
const struct tm * const timeStamp = gmtime(&saveTime);
char filename[256];
snprintf(filename,256, "%s/yuv_%d_%d_%d_%lu.yuv",
kYuvImagesOutputDirPath,
timeStamp->tm_hour,
timeStamp->tm_min,
timeStamp->tm_sec,
timeStampUsec.tv_usec);
const status_t saveBufferStatus = saveBufferToFile(((CameraBuffer*)pBuffHeader->pAppPrivate)->mapped,
pBuffHeader->nFilledLen, filename);
if (saveBufferStatus != OK) {
CAMHAL_LOGE("ERROR: %d, while saving yuv!", saveBufferStatus);
} else {
CAMHAL_LOGD("yuv_%d_%d_%d_%lu.yuv successfully saved in %s",
timeStamp->tm_hour,
timeStamp->tm_min,
timeStamp->tm_sec,
timeStampUsec.tv_usec,
kYuvImagesOutputDirPath);
}
}
#endif
stat = sendCallBacks(cameraFrame, pBuffHeader, mask, pPortParam);
}
else if (pBuffHeader->nOutputPortIndex == OMX_CAMERA_PORT_VIDEO_OUT_VIDEO) {
typeOfFrame = CameraFrame::RAW_FRAME;
pPortParam->mImageType = typeOfFrame;
{
Mutex::Autolock lock(mLock);
if( ( CAPTURE_ACTIVE & state ) != CAPTURE_ACTIVE ) {
goto EXIT;
}
}
CAMHAL_LOGD("RAW buffer done on video port, length = %d", pBuffHeader->nFilledLen);
mask = (unsigned int) CameraFrame::RAW_FRAME;
#ifdef CAMERAHAL_USE_RAW_IMAGE_SAVING
if ( mRawCapture ) {
struct timeval timeStampUsec;
gettimeofday(&timeStampUsec, NULL);
time_t saveTime;
time(&saveTime);
const struct tm * const timeStamp = gmtime(&saveTime);
char filename[256];
snprintf(filename,256, "%s/raw_%d_%d_%d_%lu.raw",
kRawImagesOutputDirPath,
timeStamp->tm_hour,
timeStamp->tm_min,
timeStamp->tm_sec,
timeStampUsec.tv_usec);
const status_t saveBufferStatus = saveBufferToFile( ((CameraBuffer*)pBuffHeader->pAppPrivate)->mapped,
pBuffHeader->nFilledLen, filename);
if (saveBufferStatus != OK) {
CAMHAL_LOGE("ERROR: %d , while saving raw!", saveBufferStatus);
} else {
CAMHAL_LOGD("raw_%d_%d_%d_%lu.raw successfully saved in %s",
timeStamp->tm_hour,
timeStamp->tm_min,
timeStamp->tm_sec,
timeStampUsec.tv_usec,
kRawImagesOutputDirPath);
stat = sendCallBacks(cameraFrame, pBuffHeader, mask, pPortParam);
}
}
#endif
} else {
CAMHAL_LOGEA("Frame received for non-(preview/capture/measure) port. This is yet to be supported");
goto EXIT;
}
if ( NO_ERROR != stat )这里上面的所有处理过程都成功了才会执行这里
{
CameraBuffer *camera_buffer;
camera_buffer = (CameraBuffer *)pBuffHeader->pAppPrivate;
CAMHAL_LOGDB("sendFrameToSubscribers error: %d", stat);
returnFrame(camera_buffer, typeOfFrame);
}
return eError;
EXIT:
CAMHAL_LOGEB("Exiting function %s because of ret %d eError=%x", __FUNCTION__, stat, eError);
if ( NO_ERROR != stat )
{
if ( NULL != mErrorNotifier )
{
mErrorNotifier->errorNotify(CAMERA_ERROR_UNKNOWN);
}
}
return eError;
}
这里具体的数据回传给app暂时不做过多说明，看看这个方法的最后处理，这里才是我真正关注的
那么这个returnFrame到底实现什么功能呢
void BaseCameraAdapter::returnFrame(CameraBuffer * frameBuf, CameraFrame::FrameType frameType)
{
status_t res = NO_ERROR;
size_t subscriberCount = 0;
int refCount = -1;
if ( NULL == frameBuf )
{
CAMHAL_LOGEA("Invalid frameBuf");
return;
}
if ( NO_ERROR == res)
{
Mutex::Autolock lock(mReturnFrameLock);
refCount = getFrameRefCount(frameBuf, frameType);
if(frameType == CameraFrame::PREVIEW_FRAME_SYNC)
{
mFramesWithDisplay--;
}
else if(frameType == CameraFrame::VIDEO_FRAME_SYNC)
{
mFramesWithEncoder--;
}
if ( 0 < refCount )
{
refCount--;
setFrameRefCount(frameBuf, frameType, refCount);
if ( mRecording && (CameraFrame::VIDEO_FRAME_SYNC == frameType) ) {
refCount += getFrameRefCount(frameBuf, CameraFrame::PREVIEW_FRAME_SYNC);
} else if ( mRecording && (CameraFrame::PREVIEW_FRAME_SYNC == frameType) ) {
refCount += getFrameRefCount(frameBuf, CameraFrame::VIDEO_FRAME_SYNC);
} else if ( mRecording && (CameraFrame::SNAPSHOT_FRAME == frameType) ) {
refCount += getFrameRefCount(frameBuf, CameraFrame::VIDEO_FRAME_SYNC);
}
}
else
{
CAMHAL_LOGDA("Frame returned when ref count is already zero!!");
return;
}
}
CAMHAL_LOGVB("REFCOUNT 0x%x %d", frameBuf, refCount);
if ( NO_ERROR == res )
{
//check if someone is holding this buffer
if ( 0 == refCount )
{
#ifdef CAMERAHAL_DEBUG
if((mBuffersWithDucati.indexOfKey((int)camera_buffer_get_omx_ptr(frameBuf)) >= 0) &&
((CameraFrame::PREVIEW_FRAME_SYNC == frameType) ||
(CameraFrame::SNAPSHOT_FRAME == frameType)))
{
LOGE("Buffer already with Ducati!! 0x%x", frameBuf);
for(int i=0;i<mBuffersWithDucati.size();i++) LOGE("0x%x", mBuffersWithDucati.keyAt(i));
}
mBuffersWithDucati.add((int)camera_buffer_get_omx_ptr(frameBuf),1);
#endif
res = fillThisBuffer(frameBuf, frameType);
}
}
}
最后我标注的地方，这个buffer用完了，就是通过这里重新fill到组件中，重复利用的，当然这是我个人的理解
先到这里了，以后再详细说了
待续。。。。。。
