高通camera框架之如何打通App-Hardware经络

xiaoxiao2025-05-30 7

许久未更新博客，今天再次重磅推出鄙人的浅显的一些总结，以供参考，该文主要是基于camera一个小功能来详细讲解java层接口如何步步调用至hardware层接口，涉及到一些机制的简单介绍，希望可以为您提供更多的参考，希望为技术类资源的整合做点微小的贡献。

目录...3

1. Introduction. 4

2. Feature特性描述... 5

2.1 特性简介....5

2.2 特性分析....5

3. ObjectTrackingfeature框架分析... 6

3.1 总体框图....6

4. Feature基本流程... 7

4.1 Object tracking feature函数执行流程....7

4.1.1 函数初始化调用流程....7

4.1.2 数据Callback流程....10

5. Design idea. 21

5.1 Callback设计机制....21

5.2 Eventhandler设计机制....24

5.3 JNI调用java接口函数....25

5.4 Client端数据处理....29

5.5 Service端数据处理....30

2.1 特性简介

1) Feature name:

ObjectTracking；

2) Feature简介:手动对焦物体，移动设备的过程中会自动追踪物体，该feature主要通过ArcSoft算法处理返回的坐标信息确定物体位置；

2.2 特性分析

1) 处理过程：

选择追踪物体：

Application层选择物体 -> 物体坐标信息 -> ArcSoft算法确定要追踪物体信息

定位物体：

ArcSoft算法获取物体位置信息 –> 物体坐标信息 -> callback至Application层

2) 应用层:

a、Draw rectangle on detected and tracking area;

b、Add touch focus mode with object tracking or just replace current touchfocus mode;

后续完善该部分内容

4.1.1 函数初始化调用流程

Focus mode: objecttracking

vim./vendor/semc/packages/apps/camera-addons/CameraUI/src/com/sonyericsson/android/camera/controller/EventDispatcher.java

static class ObjectTrackingEventimplementsControllerEventSender {

@Override

public voidsend(EventAction action,ControllerEventSourcesource,Rect position) {

switch(action){

case DOWN:

break;

case UP:

Executor.sendEvent(ControllerEvent.EV_OBJECT_TRACKING_START,source,

0, position);

break;

case CANCEL:

Executor.sendEvent(ControllerEvent.EV_OBJECT_TRACKING_LOST,source);

break;

}

Thenext is ControllerMessageHandler.java dispatch EV_AF_START event：

vim./vendor/semc/packages/apps/camera-addons/CameraUI/src/com/sonyericsson/android/camera/controller/ControllerMessageHandler.java

private synchronized voiddispatch(ControllerMessage message) {

……

switch(message.mEventId) {

caseEV_ABORT:

mCurrentState.handleAbort(message);

break;

…...

caseEV_OBJECT_TRACKING_LOST:

mCurrentState.handleObjectTrackingLost(message);

break;

caseEV_OBJECT_TRACKING_START:

mCurrentState.handleObjectTrackingStart(message);

break;

…...

}

vim./vendor/semc/packages/apps/camera-addons/CameraUI/src/com/sonyericsson/android/camera/controller/StateTransitionController.java

public void handleObjectTrackingStart(ControllerMessage message) {

mObjectTracking.start((Rect) message.mArg2);

}

vim./vendor/semc/packages/apps/camera-addons/CameraUI/src/com/sonyericsson/android/camera/controller/ObjectTracking.java

public void start(Rect position) {

if(position != null) {

mPosition=position;

Rect rectIS =newRect();

if(mController.mCameraDevice.isObjectTrackingRunning() &&

!mController.getParams().getTouchCapture().getBooleanValue()&&

rectIS.intersects(mPosition,

PositionConverter.getInstance().

convertDeviceToFace(mTrackingPosition))){

Executor.sendEmptyEvent(ControllerEvent.EV_OBJECT_TRACKING_LOST);

return;

}

if(mIsAlreadyLost) {

startTracking(position);

}else {

// Wait till previous object is lost when restart.

stop(false);

mShouldWaitForLost= true;

}

private void startTracking(Rect position) {

mCallback=new ObjectTrackingCallback();

mController.mCameraWindow.startObjectTrackingAnimation(position);

mController.mCameraDevice.startObjectTracking(

PositionConverter.getInstance().convertFaceToDevice(position),

mCallback);

}

vim./vendor/semc/packages/apps/camera-addons/CameraUI/src/com/sonyericsson/android/camera/device/CameraDevice.java

public void startObjectTracking(Rect position,ObjectTrackingCallbackcb) {

……

mCameraExtension.setObjectTrackingCallback(cb, //设置callback函数，用于从ArcSoft获取位置信息

CameraDeviceUtil.OBJECT_TRACKING_LOW_PASS_FILTER_STRENGTH,

CameraDeviceUtil.OBJECT_TRACKING_MINIMAL_INTERVAL_MS);

mCameraExtension.startObjectTracking(); //选择tracking位置，设置到ArcSoft

mCameraExtension.selectObject(position.centerX(),position.centerY());

mIsObjectTrackingRunning= true;

……

newEachCameraStatusPublisher(mCameraActivity,mCameraId)

.put(new ObjectTracking(ObjectTracking.Value.ON))

.publish();

}

vimvendor/semc/frameworks/base/libs/camera-extension/api/src/com/sonyericsson/cameraextension/CameraExtension.java

public final voidstartObjectTracking() {

……

if(mCamera != null) {

mCamera.startObjectTracking();

}

vimframeworks/base/core/java/android/hardware/Camera.java

private native final void_startObjectTracking();

publicvoidstartObjectTracking() {

_startObjectTracking();

}

vimframeworks/base/core/jni/android_hardware_Camera.cpp

static voidandroid_hardware_Camera_startObjectTracking(JNIEnv *env,jobject thiz)

{

JNICameraContext* context;

sp<Camera>camera = get_native_camera(env,thiz, &context);

if(camera == 0)return;

boolisSuccess = context->setUpObjectTracking(env);

……

if(camera->sendCommand(CAMERA_CMD_START_OBJECT_TRACKING,0, 0) != NO_ERROR) {

jniThrowRuntimeException(env,"start objecttracking failed");

}

vim frameworks/av/camera/Camera.cpp

status_t Camera::sendCommand(int32_t cmd,int32_t arg1,int32_t arg2)

{

sp <ICamera> c = mCamera;

if(c == 0)return NO_INIT;

returnc->sendCommand(cmd,arg1, arg2);

}

vimframeworks/av/services/camera/libcameraservice/api1/CameraClient.cpp

status_t CameraClient::sendCommand(int32_t cmd,int32_t arg1,int32_t arg2) {

…...

elseif(cmd == CAMERA_CMD_START_OBJECT_TRACKING) {

enableMsgType(CAMERA_MSG_OBJECT_TRACKING);

mLowPassFilterObjectTracking->isStartObjectTracking =true;

}

…...

/* MM-MC-SomcAddForSoMCAP-00+} */

return mHardware->sendCommand(cmd,arg1, arg2);

}

void CameraClient::enableMsgType(int32_t msgType) {

android_atomic_or(msgType,&mMsgEnabled);

mHardware->enableMsgType(msgType);

}

vimframeworks/av/services/camera/libcameraservice/device1/CameraHardwareInterface.h

void enableMsgType(int32_t msgType)

{

if(mDevice->ops->enable_msg_type)

mDevice->ops->enable_msg_type(mDevice,msgType);

}

status_t sendCommand(int32_t cmd,int32_t arg1,int32_t arg2)

{

if(mDevice->ops->send_command)

returnmDevice->ops->send_command(mDevice,cmd, arg1, arg2);

returnINVALID_OPERATION;

}

vimhardware/qcom/camera/QCamera2/HAL/QCamera2HWI.cpp

camera_device_ops_tQCamera2HardwareInterface::mCameraOps = {

set_preview_window: QCamera2HardwareInterface::set_preview_window,

set_callbacks: QCamera2HardwareInterface::set_CallBacks,

enable_msg_type: QCamera2HardwareInterface::enable_msg_type,

disable_msg_type: QCamera2HardwareInterface::disable_msg_type,

……

get_parameters: QCamera2HardwareInterface::get_parameters,

put_parameters: QCamera2HardwareInterface::put_parameters,

send_command: QCamera2HardwareInterface::send_command,

release: QCamera2HardwareInterface::release,

dump: QCamera2HardwareInterface::dump,

};

4.1.2数据Callback流程

下面从hal层接口开始往上层进行分析数据回调过程：

1)、CameraHardwareInterface提供的回调函数：

vimframeworks/av/services/camera/libcameraservice/device1/CameraHardwareInterface.h

Callback函数：

static void__notify_cb(int32_t msg_type,int32_t ext1,

int32_t ext2,void*user)

{

CameraHardwareInterface *__this =

static_cast<CameraHardwareInterface *>(user);

__this->mNotifyCb(msg_type,ext1, ext2, __this->mCbUser);

}

static void__data_cb(int32_t msg_type,

constcamera_memory_t *data,unsignedint index,

camera_frame_metadata_t *metadata,

void*user)

{

CameraHardwareInterface *__this =

static_cast<CameraHardwareInterface *>(user);

sp<CameraHeapMemory> mem(static_cast<CameraHeapMemory *>(data->handle));

if(index >= mem->mNumBufs) {

return;

}

__this->mDataCb(msg_type,mem->mBuffers[index],metadata,__this->mCbUser);

}

Set callback函数：

void setCallbacks(notify_callback notify_cb,

data_callback data_cb,

data_callback_timestamp data_cb_timestamp,

void* user)

{

mNotifyCb = notify_cb;

mDataCb = data_cb;

mDataCbTimestamp = data_cb_timestamp;

mCbUser = user;

if(mDevice->ops->set_callbacks) {

mDevice->ops->set_callbacks(mDevice, //调用hal层set_callback函数

__notify_cb,

__data_cb,

__data_cb_timestamp,

__get_memory,

this);

}

上面的set_callback函数最终会调用hal层的QCamera2HardwareInterface::setCallBacks函数，简要分析Hal层callback函数相关处理：

vimhardware/qcom/camera/QCamera2/HAL/QCamera2HWI.cpp

int QCamera2HardwareInterface::setCallBacks(camera_notify_callbacknotify_cb,

camera_data_callbackdata_cb,

camera_data_timestamp_callbackdata_cb_timestamp,

camera_request_memoryget_memory,

void*user)

{

mNotifyCb = notify_cb;

mDataCb = data_cb;

mDataCbTimestamp =data_cb_timestamp;

mGetMemory = get_memory;

mCallbackCookie = user;

m_cbNotifier.setCallbacks(notify_cb,data_cb, data_cb_timestamp,user);

returnNO_ERROR;

}

vimhardware/qcom/camera/QCamera2/HAL/QCamera2HWICallbacks.cpp

void QCameraCbNotifier::setCallbacks(camera_notify_callbacknotifyCb,

camera_data_callbackdataCb,

camera_data_timestamp_callbackdataCbTimestamp,

void *callbackCookie)

{

if( (NULL == mNotifyCb ) &&

( NULL ==mDataCb ) &&

( NULL ==mDataCbTimestamp ) &&

( NULL == mCallbackCookie) ) {

mNotifyCb =notifyCb;

mDataCb =dataCb;

mDataCbTimestamp= dataCbTimestamp;

mCallbackCookie= callbackCookie;

mActive =true;

mProcTh.launch(cbNotifyRoutine,this); //开启线程处理callback信息

}else {

ALOGE("%s: Camera callback notifier already initialized!",

__func__);

}

void *QCameraCbNotifier::cbNotifyRoutine(void* data)

{

intrunning =1;

intret;

QCameraCbNotifier *pme =(QCameraCbNotifier *)data;

QCameraCmdThread *cmdThread =&pme->mProcTh;

cmdThread->setName("CAM_cbNotify");

uint8_t isSnapshotActive =FALSE;

boollongShotEnabled =false;

uint32_t numOfSnapshotExpected=0;

uint32_t numOfSnapshotRcvd =0;

int32_t cbStatus = NO_ERROR;

CDBG("%s:E",__func__);

do{

ret =cam_sem_wait(&cmdThread->cmd_sem);

……

}while (ret !=0);

camera_cmd_type_tcmd = cmdThread->getCmd();

switch(cmd) {

caseCAMERA_CMD_TYPE_START_DATA_PROC:

{

isSnapshotActive= TRUE;

numOfSnapshotExpected= pme->mParent->numOfSnapshotsExpected();

/*MM-YW-Integrate Arcsoft Snapshot Fature-00+{*/

#ifdef USE_ARCSOFT_FEATURE

if(NULL !=pme->mParent->mArcSoft_Feature)

numOfSnapshotExpected+= pme->mParent->mArcSoft_Feature->mSnapshotInfo.extra_burst_cnt;

#endif

/*MM-YW-Integrate Arcsoft Snapshot Fature-00+}*/

longShotEnabled= pme->mParent->isLongshotEnabled();

numOfSnapshotRcvd= 0;

}

break;

caseCAMERA_CMD_TYPE_STOP_DATA_PROC:

{

pme->mDataQ.flushNodes(matchSnapshotNotifications);

isSnapshotActive= FALSE;

numOfSnapshotExpected= 0;

numOfSnapshotRcvd= 0;

}

break;

caseCAMERA_CMD_TYPE_DO_NEXT_JOB:

{

qcamera_callback_argm_t*cb = //从队取出信息

(qcamera_callback_argm_t*)pme->mDataQ.dequeue();

cbStatus =NO_ERROR;

if (NULL != cb) {

CDBG("%s:cb type %d received",

__func__,

cb->cb_type);

if (pme->mParent->msgTypeEnabledWithLock(cb->msg_type)){

switch (cb->cb_type){

case QCAMERA_NOTIFY_CALLBACK:

{

if (cb->msg_type== CAMERA_MSG_FOCUS) {

ATRACE_INT("Camera:AutoFocus",0);

CDBG_HIGH("[KPIPerf] %s : PROFILE_SENDING_FOCUS_EVT_TO APP",

__func__);

}

if (pme->mNotifyCb){

pme->mNotifyCb(cb->msg_type,

cb->ext1,

cb->ext2,

pme->mCallbackCookie);

} else{

ALOGE("%s: notify callback not set!",

__func__);

}

break;

case QCAMERA_DATA_CALLBACK:

{

if (pme->mDataCb){

pme->mDataCb(cb->msg_type,

cb->data,

cb->index,

cb->metadata,

pme->mCallbackCookie);

} else{

ALOGE("%s: data callback not set!",

__func__);

}

break;

case QCAMERA_DATA_TIMESTAMP_CALLBACK:

{

if(pme->mDataCbTimestamp){

pme->mDataCbTimestamp(cb->timestamp,

cb->msg_type,

cb->data,

cb->index,

pme->mCallbackCookie);

} else{

ALOGE("%s:datacb with tmp not set!",

__func__);

}

break;

case QCAMERA_DATA_SNAPSHOT_CALLBACK:

{

if (TRUE ==isSnapshotActive && pme->mDataCb ) {

if(!longShotEnabled) {

numOfSnapshotRcvd++;

/*MM-YW-IntegrateArcsoft Snapshot Fature-01+{*/

#ifdefUSE_ARCSOFT_FEATURE

if((NULL !=pme->mParent->mArcSoft_Feature) &&pme->mParent->mArcSoft_Feature->mSnapshotInfo.is_snapshot_done)

{

pme->mParent->processSyncEvt(QCAMERA_SM_EVT_SNAPSHOT_DONE,NULL);

pme->mParent->mArcSoft_Feature->ArcSoft_SendSnapshotEvt(ARCSOFT_S_EVT_DONE,FALSE,NULL);

}else

#endif

/*MM-YW-IntegrateArcsoft Snapshot Fature-01+}*/

if (numOfSnapshotExpected>0 &&

numOfSnapshotExpected== numOfSnapshotRcvd) {

//notify HWI that snapshot is done

pme->mParent->processSyncEvt(QCAMERA_SM_EVT_SNAPSHOT_DONE,

NULL);

}

pme->mDataCb(cb->msg_type,

cb->data,

cb->index,

cb->metadata,

pme->mCallbackCookie);

}

break;

……

}while (running);

CDBG("%s:X",__func__);

returnNULL;

}

2)、CameraService处理HAL消息函数：

vimframeworks/av/services/camera/libcameraservice/api1/CameraClient.cpp

set callback:

status_t CameraClient::initialize(CameraModule *module) {

intcallingPid = getCallingPid();

status_t res;

// Verify ops permissions

res = startCameraOps();

if(res != OK) {

returnres;

}

charcamera_device_name[10];

snprintf(camera_device_name,sizeof(camera_device_name),"%d", mCameraId);

mHardware =new CameraHardwareInterface(camera_device_name);

res = mHardware->initialize(module);

……

mHardware->setCallbacks(notifyCallback,

dataCallback,

dataCallbackTimestamp,

(void *)(uintptr_t)mCameraId);

// Enable zoom, error, focus, and metadata messages by default

enableMsgType(CAMERA_MSG_ERROR | CAMERA_MSG_ZOOM |CAMERA_MSG_FOCUS |

CAMERA_MSG_PREVIEW_METADATA | CAMERA_MSG_FOCUS_MOVE);

returnOK;

}

Callback函数：

void CameraClient::notifyCallback(int32_t msgType,int32_t ext1,

int32_t ext2,void* user) {

sp<CameraClient> client =static_cast<CameraClient*>(getClientFromCookie(user).get());

if(client.get() == nullptr)return;

if(!client->lockIfMessageWanted(msgType))return;

switch(msgType) {

caseCAMERA_MSG_SHUTTER:

// ext1 is the dimension of the yuv picture.

client->handleShutter();

break;

default:

client->handleGenericNotify(msgType,ext1, ext2);

break;

}

void CameraClient::dataCallback(int32_t msgType,

constsp<IMemory>& dataPtr,camera_frame_metadata_t *metadata,void* user) {

sp<CameraClient> client =static_cast<CameraClient*>(getClientFromCookie(user).get());

if(client.get() == nullptr)return;

if(!client->lockIfMessageWanted(msgType))return;

……

switch(msgType & ~CAMERA_MSG_PREVIEW_METADATA) {

caseCAMERA_MSG_PREVIEW_FRAME:

client->handlePreviewData(msgType,dataPtr, metadata);

break;

caseCAMERA_MSG_POSTVIEW_FRAME:

client->handlePostview(dataPtr);

break;

caseCAMERA_MSG_RAW_IMAGE:

client->handleRawPicture(dataPtr);

break;

caseCAMERA_MSG_COMPRESSED_IMAGE:

client->handleCompressedPicture(dataPtr);

break;

/* MM-MC-SomcAddForSoMCAP-00+{ */

caseCAMERA_MSG_OBJECT_TRACKING:

client->handleObjectTracking(dataPtr);

break;

/* MM-MC-SomcAddForSoMCAP-00+} */

default:

client->handleGenericData(msgType,dataPtr, metadata);

break;

}

// handleObjectTracking

void CameraClient::handleObjectTracking(constsp<IMemory>&mem) {

LOG2("%s:",__FUNCTION__);

sp<ICameraClient> c = mRemoteCallback;

mLock.unlock();

clock_t nowMilliSec =1000 * clock() /CLOCKS_PER_SEC;

……

// reset isStartObjectTracking flag

mLowPassFilterObjectTracking->isStartObjectTracking =false;

// return callback

if(c != NULL) { //调用客户端回调函数

c->dataCallback(CAMERA_MSG_OBJECT_TRACKING,mem, NULL);

}

return;

}

……

}

3)、Client客户端处理：

vim frameworks/av/camera/Camera.cpp

void Camera::notifyCallback(int32_t msgType,int32_t ext1,int32_t ext2)

{

returnCameraBaseT::notifyCallback(msgType,ext1, ext2);

}

// callback from cameraservice when frame or image is ready

void Camera::dataCallback(int32_t msgType,constsp<IMemory>& dataPtr,

camera_frame_metadata_t *metadata)

{

sp<CameraListener> listener;

{

Mutex::Autolock _l(mLock);

listener = mListener;

}

if(listener != NULL) {

listener->postData(msgType,dataPtr, metadata);

}

4)、JNI:android_hardware_Camera.cpp

vim frameworks/base/core/jni/android_hardware_Camera.cpp

void JNICameraContext::postData(int32_t msgType,constsp<IMemory>& dataPtr,

camera_frame_metadata_t *metadata)

{

……

int32_t dataMsgType = msgType & ~CAMERA_MSG_PREVIEW_METADATA;

// return data based on callback type

switch(dataMsgType) {

caseCAMERA_MSG_VIDEO_FRAME:

// should never happen

break;

// For backward-compatibility purpose, if there is no callback

// buffer for raw image, the callback returns null.

caseCAMERA_MSG_RAW_IMAGE:

ALOGV("rawCallback");

if (mRawImageCallbackBuffers.isEmpty()) {

env->CallStaticVoidMethod(mCameraJClass,fields.post_event,

mCameraJObjectWeak,dataMsgType,0, 0,NULL);

} else {

copyAndPost(env,dataPtr,dataMsgType);

}

break;

/* MM-MC-SomcAddForSoMCAP-00+{ */

caseCAMERA_MSG_OBJECT_TRACKING:

{

……

ssize_t offset;

size_t size;

sp<IMemoryHeap> heap;

heap = dataPtr->getMemory(&offset,&size);

ALOGV("objecttracking callback:mem off=%d, size=%d",(int) offset,(int) size);

camera_ex_msg_object_tracking_t *cb =(camera_ex_msg_object_tracking_t *) heap->base();

jobject object_tracking_result;

if (cb != NULL) {

object_tracking_result = convertObjectTrackingResult(env,cb);

} else {

ALOGE("objecttracking callback: heap is null");

env->CallStaticVoidMethod(mCameraJClass,fields.post_event,

mCameraJObjectWeak,CAMERA_MSG_OBJECT_TRACKING,0, 0,NULL);

return;

}//数据通过jni层传给java层

env->CallStaticVoidMethod(mCameraJClass,fields.post_event,

mCameraJObjectWeak,CAMERA_MSG_OBJECT_TRACKING,0, 0, object_tracking_result);

}

break;

/* MM-MC-SomcAddForSoMCAP-00+} */

// There is no data.

case0:

break;

default:

ALOGV("dataCallback(%d,%p)",dataMsgType,dataPtr.get());

copyAndPost(env,dataPtr,dataMsgType);

break;

}

// post frame metadata to Java

if(metadata && (msgType &CAMERA_MSG_PREVIEW_METADATA)) {

postMetadata(env,CAMERA_MSG_PREVIEW_METADATA,metadata);

}

5)、JAVA:Camera.java

vim frameworks/base/core/java/android/hardware/Camera.java

//接收sendMessage数据，传输到extensoin（CameraExtension.java）

private class EventHandler extendsHandler

{

private finalCameramCamera;

publicEventHandler(Camera c,Looper looper) {

super(looper);

mCamera=c;

}

@Override

public voidhandleMessage(Message msg) {

switch(msg.what) {

caseCAMERA_MSG_SHUTTER:

if (mShutterCallback!= null) {

mShutterCallback.onShutter();

}

return;

caseCAMERA_MSG_RAW_IMAGE:

if (mRawImageCallback!= null) {

mRawImageCallback.onPictureTaken((byte[])msg.obj,mCamera);

}

return;

……

caseCAMERA_MSG_OBJECT_TRACKING:

if (mObjectTrackingFWCallback!= null) {

Log.e(TAG,"jay test call back");

mObjectTrackingFWCallback.onObjectTrackingFWCallback((ObjectTrackingResult)msg.obj, mCamera);

}

return;

/* MM-MC-SomcAddForSoMCAP-00+} */

default:

Log.e(TAG,"Unknown message type " + msg.what);

return;

}

}//接受jni层数据并发送sendMessage

private static voidpostEventFromNative(Object camera_ref,

int what, intarg1, int arg2, Object obj)

{

Camera c = (Camera)((WeakReference)camera_ref).get();

if(c == null)

return;

if(c.mEventHandler!= null) {

Message m = c.mEventHandler.obtainMessage(what,arg1, arg2, obj);

c.mEventHandler.sendMessage(m);

}

6)、Extension frameworks层callback

vimvendor/semc/frameworks/base/libs/camera-extension/api/src/com/sonyericsson/cameraextension/CameraExtension.java

public interface ObjectTrackingCallback {

voidonObjectTracked(ObjectTrackingResultobjectTrackingResult);

}

public final void setObjectTrackingCallback(

finalObjectTrackingCallback cb,

intlowPassFilterStrength,

intminimumIntervalMilliSec) {

if(mIsReleased){

return;

}

mObjectTrackingCallback = cb;

if(Integer.MAX_VALUE< minimumIntervalMilliSec) {

minimumIntervalMilliSec = minimumIntervalMilliSec;

}

/* ++ Somc-integrate-CameraExtension-01 */

//setObjectTrackingLowPassFilterPrameters(lowPassFilterStrength,minimumIntervalMilliSec);

if(mCamera!= null) {

if(mObjectTrackingFWCallback == null) {

mObjectTrackingFWCallback = new OTCallback();

}

//将mObjectTrackingFWCallback传输到下层

mCamera.setObjectTrackingLowPassFilterPrameters(mObjectTrackingFWCallback,

lowPassFilterStrength,minimumIntervalMilliSec);

}

/* -- Somc-integrate-CameraExtension-01 */

}

/* ++ Somc-integrate-CameraExtension-01*/

class OTCallbackimplementsCamera.ObjectTrackingFWCallback {

public voidonObjectTrackingFWCallback(Camera.ObjectTrackingResultobjectTrackingResult,

Camera camera) {

if(mObjectTrackingCallback != null&& objectTrackingResult != null) {

……

if(mObjectTrackingResult == null)

mObjectTrackingResult = newObjectTrackingResult();

mObjectTrackingResult.mRectOfTrackedObject =new android.graphics.Rect(

objectTrackingResult.mRectOfTrackedObject.left,objectTrackingResult.mRectOfTrackedObject.top,

objectTrackingResult.mRectOfTrackedObject.right,objectTrackingResult.mRectOfTrackedObject.bottom);

mObjectTrackingResult.mIsLost =objectTrackingResult.mIsLost;

mObjectTrackingCallback.onObjectTracked(mObjectTrackingResult); //传递到上层UI

}

5. Design idea

5.1 Callback设计机制

1) application层定义callback函数：

定义接口：

vimvendor/semc/frameworks/base/libs/camera-extension/api/src/com/sonyericsson/cameraextension/CameraExtension.java

publicinterface ObjectTrackingCallback {

voidonObjectTracked(ObjectTrackingResultobjectTrackingResult);

}

定义callback函数，是真实处理底层数据的函数：

vimvendor/semc/packages/apps/camera-addons/CameraUI/src/com/sonyericsson/android/camera/controller/ObjectTracking.java

privateclass ObjectTrackingCallbackimplementsCameraExtension.ObjectTrackingCallback {

@Override

public voidonObjectTracked(ObjectTrackingResultresult) {

……

if(mShouldWaitForLost) {

if(!result.mIsLost) {

// Ignore detect object event for wait next lost event.

if(CameraLogger.DEBUG) CameraLogger.d(TAG,"onObjectTracked: ignoredetect.");

return;

}else {

// Restart object tracking after lost event.

if(CameraLogger.DEBUG) CameraLogger.d(TAG,"onObjectTracked: restart.");

mController.mCameraDevice.stopObjectTrackingCallback();

startTracking(mPosition);

mShouldWaitForLost =false;

}

// Ignorecontinuous lost event.

if(mIsAlreadyLost&& result.mIsLost) {

if(CameraLogger.DEBUG) CameraLogger.d(TAG,"onObjectTracked: ignore lost");

return;

}

mIsAlreadyLost= result.mIsLost;

if(result.mIsLost) {

mHandler.startTimeoutCount();

}else {

mHandler.stopTimeoutCount();

Executor.postEvent(ControllerEvent.EV_OBJECT_TRACKING,0,

result.mRectOfTrackedObject);

}

调用java接口函数注册callback函数：

privatevoid startTracking(Rect position) {

if(CameraLogger.DEBUG) CameraLogger.d(TAG,"startTracking: " + position);

mCallback = new ObjectTrackingCallback(); //callback函数

mController.mCameraWindow.startObjectTrackingAnimation(position);

mController.mCameraDevice.startObjectTracking(

PositionConverter.getInstance().convertFaceToDevice(position),

mCallback); //传递callback函数

}

vimvendor/semc/packages/apps/camera-addons/CameraUI/src/com/sonyericsson/android/camera/device/CameraDevice.java

public void startObjectTracking(Rect position,ObjectTrackingCallback cb) {

…… //接口函数-frameworks层提供

mCameraExtension.setObjectTrackingCallback(cb//cb即为上面传递下来的callback函数,

CameraDeviceUtil.OBJECT_TRACKING_LOW_PASS_FILTER_STRENGTH,

CameraDeviceUtil.OBJECT_TRACKING_MINIMAL_INTERVAL_MS);

mCameraExtension.startObjectTracking();

mCameraExtension.selectObject(position.centerX(),position.centerY());

mIsObjectTrackingRunning= true;

……

newEachCameraStatusPublisher(mCameraActivity,mCameraId)

.put(newObjectTracking(ObjectTracking.Value.ON))

.publish();

}

实现用于注册callback函数的java接口函数：

vimvendor/semc/frameworks/base/libs/camera-extension/api/src/com/sonyericsson/cameraextension/CameraExtension.java

public final void setObjectTrackingCallback(

finalObjectTrackingCallback cb,

intlowPassFilterStrength,

intminimumIntervalMilliSec) {

if(mIsReleased) {

return;

}

mObjectTrackingCallback = cb; //获得application层传下的callback函数指针

if(Integer.MAX_VALUE <minimumIntervalMilliSec) {

minimumIntervalMilliSec = minimumIntervalMilliSec;

}

/* ++Somc-integrate-CameraExtension-01 */

//setObjectTrackingLowPassFilterPrameters(lowPassFilterStrength,minimumIntervalMilliSec);

if(mCamera != null) {

if(mObjectTrackingFWCallback == null) {

mObjectTrackingFWCallback = newOTCallback(); //又一callback函数

}//调用另一注册函数注册另一个callback函数2（双callback）

mCamera.setObjectTrackingLowPassFilterPrameters(mObjectTrackingFWCallback,

lowPassFilterStrength,minimumIntervalMilliSec);

}

/* -- Somc-integrate-CameraExtension-01*/

}

2) 接口层定义callback函数：

定义接口：

vimframeworks/base/core/java/android/hardware/Camera.java

publicinterface ObjectTrackingFWCallback {

voidonObjectTrackingFWCallback(ObjectTrackingResult objectTrackingResult,Camera camera);

};

定义callback函数，是真实处理底层数据的函数：

vimvendor/semc/frameworks/base/libs/camera-extension/api/src/com/sonyericsson/cameraextension/CameraExtension.java

classOTCallbackimplementsCamera.ObjectTrackingFWCallback {

public voidonObjectTrackingFWCallback(Camera.ObjectTrackingResult objectTrackingResult,

Camera camera) {

if(mObjectTrackingCallback != null&& objectTrackingResult != null) {

……

if(mObjectTrackingResult == null)

mObjectTrackingResult = newObjectTrackingResult();

mObjectTrackingResult.mRectOfTrackedObject =new android.graphics.Rect(

objectTrackingResult.mRectOfTrackedObject.left,objectTrackingResult.mRectOfTrackedObject.top,

objectTrackingResult.mRectOfTrackedObject.right,objectTrackingResult.mRectOfTrackedObject.bottom);

mObjectTrackingResult.mIsLost = objectTrackingResult.mIsLost;

mObjectTrackingCallback.onObjectTracked(mObjectTrackingResult);

} //由上述处理可知，callback2将得到的数据传递给callback1—>传至application

}

实现用于注册callback的接口函数：

vim frameworks/base/core/java/android/hardware/Camera.java

publicvoid setObjectTrackingLowPassFilterPrameters(ObjectTrackingFWCallbackcb, int lowPassFilterStrength, intminimumIntervalMilliSec){

mObjectTrackingFWCallback =cb;

_setObjectTrackingLowPassFilterPrameters(lowPassFilterStrength,minimumIntervalMilliSec);

}

接下来通过handler机制将client端得到的数据传给当前callback函数（mObjectTrackingFWCallback）。

5.2 Eventhandler设计机制

1) Eventhandle初始化：

vimframeworks/base/core/java/android/hardware/Camera.java

privateint cameraInitVersion(intcameraId,inthalVersion) {

mShutterCallback= null;

mRawImageCallback= null;

mJpegCallback= null;

mPreviewCallback= null;

mPostviewCallback= null;

mUsingPreviewAllocation=false;

mZoomListener= null;

/* ### QC ADD-ONS: START */

mCameraDataCallback= null;

mCameraMetaDataCallback=null;

/* ### QC ADD-ONS: END */

Looper looper;

if((looper= Looper.myLooper()) !=null) { //获得当前线程looper

mEventHandler = new EventHandler(this, looper);//mEventHandler用于和looper交互

}else if ((looper= Looper.getMainLooper()) !=null) {

mEventHandler= new EventHandler(this,looper);

}else {

mEventHandler= null;

}

returnnative_setup(newWeakReference<Camera>(this),cameraId,halVersion,

ActivityThread.currentOpPackageName());

}

2) 向线程队列发送数据：

privatestatic void postEventFromNative(Object camera_ref, //该函数在jni中被调用（C++调用java接口函数）

intwhat,int arg1, int arg2,Objectobj)

{

Camera c = (Camera)((WeakReference)camera_ref).get();

if(c == null)

return;

if(c.mEventHandler!=null) {

Message m = c.mEventHandler.obtainMessage(what,arg1, arg2, obj); //组合队列信息

c.mEventHandler.sendMessage(m);//发送数据

}

3) 接收队列数据：

privateclass EventHandlerextendsHandler

{

private finalCamera mCamera;

publicEventHandler(Camera c,Looper looper) {

super(looper);

mCamera = c;

}

@Override

public voidhandleMessage(Message msg) {

switch(msg.what) {

…...

case CAMERA_MSG_OBJECT_TRACKING:

if(mObjectTrackingFWCallback != null) {

Log.e(TAG, "jay test call back"); //将数据传递给callback函数

mObjectTrackingFWCallback.onObjectTrackingFWCallback((ObjectTrackingResult)msg.obj,mCamera);

}

return;

……

}

5.3 JNI调用java接口函数

vimframeworks/base/core/jni/android_hardware_Camera.cpp

fields.post_event = GetStaticMethodIDOrDie(env,clazz, "postEventFromNative",//java层函数名

"(Ljava/lang/Object;IIILjava/lang/Object;)V");

该函数在client被调用，它会调用java层函数，将数据传至java接口：

void JNICameraContext::postData(int32_t msgType,constsp<IMemory>&dataPtr,

camera_frame_metadata_t *metadata)

{

// VM pointer will be NULL if objectis released

Mutex::Autolock _l(mLock);

JNIEnv *env =AndroidRuntime::getJNIEnv();

if(mCameraJObjectWeak == NULL) {

ALOGW("callback on dead camera object");

return;

}

int32_t dataMsgType = msgType& ~CAMERA_MSG_PREVIEW_METADATA;

// return data based on callback type

switch(dataMsgType) {

caseCAMERA_MSG_VIDEO_FRAME:

// should never happen

break;

// For backward-compatibilitypurpose, if there is no callback

// buffer for raw image, the callbackreturns null.

caseCAMERA_MSG_RAW_IMAGE:

ALOGV("rawCallback");

if(mRawImageCallbackBuffers.isEmpty()) {

env->CallStaticVoidMethod(mCameraJClass,fields.post_event,

mCameraJObjectWeak,dataMsgType,0, 0,NULL);

}else {

copyAndPost(env, dataPtr, dataMsgType);

}

break;

/* MM-MC-SomcAddForSoMCAP-00+{ */

caseCAMERA_MSG_OBJECT_TRACKING:

{

ALOGV("object tracking callback");

if(dataPtr == NULL) {

ALOGE("%s: mem is null",__FUNCTION__);

env->CallStaticVoidMethod(mCameraJClass,fields.post_event,

mCameraJObjectWeak,dataMsgType,0, 0,NULL);

return;

}

ssize_t offset;

size_t size;

sp<IMemoryHeap> heap;

heap =dataPtr->getMemory(&offset,&size);

ALOGV("object tracking callback:mem off=%d,size=%d",(int) offset,(int) size);

camera_ex_msg_object_tracking_t*cb = (camera_ex_msg_object_tracking_t *) heap->base();

jobject object_tracking_result;

if(cb != NULL) {

object_tracking_result = convertObjectTrackingResult(env,cb);

}else {

ALOGE("object tracking callback: heap isnull");

env->CallStaticVoidMethod(mCameraJClass,fields.post_event,

mCameraJObjectWeak,CAMERA_MSG_OBJECT_TRACKING,0, 0,NULL);

return;

}

env->CallStaticVoidMethod(mCameraJClass,fields.post_event,

mCameraJObjectWeak,CAMERA_MSG_OBJECT_TRACKING,0, 0,object_tracking_result); //使用android VM接口函数实现对java函数的调用

}

break;

/* MM-MC-SomcAddForSoMCAP-00+} */

// There is no data.

case0:

break;

default:

ALOGV("dataCallback(%d, %p)",dataMsgType,dataPtr.get());

copyAndPost(env,dataPtr, dataMsgType);

break;

}

// post frame metadata to Java

if(metadata && (msgType &CAMERA_MSG_PREVIEW_METADATA)) {

postMetadata(env,CAMERA_MSG_PREVIEW_METADATA,metadata);

}

下面简要分析convertObjectTrackingResult，进一步理解jni如何调用java类和方法：

convertObjectTrackingResult函数需要调用的java层的类和方法：

vimframeworks/base/core/java/android/hardware/Camera.java

public static class ObjectTrackingResult {

publicRect mRectOfTrackedObject;

public booleanmIsLost;

}

vimframeworks/base/graphics/java/android/graphics/Rect.java

public final class Rectimplements Parcelable{

public intleft;

public inttop;

public intright;

public intbottom;

…...

public void set(intleft, int top, intright, int bottom) {

this.left= left;

this.top= top;

this.right= right;

this.bottom= bottom;

}

…...

}

jni获取java层jclass ID（类ID）、jmethod ID（方法函数ID）、jfield ID（变量ID）：

vimframeworks/base/core/jni/android_hardware_Camera.cpp

bool JNICameraContext::setUpObjectTracking(JNIEnv* env)

{

Mutex::Autolock _l(mLock);

objecttracking_callback_cookie *c = &objectTrackingCookie;

……

// Get jclass ID.

jclass class_results = env->FindClass(//获取javaObjectTrackingResult类

"android/hardware/Camera$ObjectTrackingResult");

jclass class_rect = env->FindClass(//获取java Rect类

"android/graphics/Rect");

c->results_clazz = (jclass)env->NewGlobalRef(class_results);

c->rect_clazz = (jclass)env->NewGlobalRef(class_rect);

// Get jmethod ID.

c->rect_set_mid =env->GetMethodID(c->rect_clazz,"set","(IIII)V"); //获取set方法

// Get jfield ID. //获取变量mRectOfTrackedObject

c->mRectOfTrackedObject_fid= env->GetFieldID(c->results_clazz,"mRectOfTrackedObject",

"Landroid/graphics/Rect;"); //获取变量mIsLost

c->mIsLost_fid =env->GetFieldID(c->results_clazz,"mIsLost","Z");

env->DeleteLocalRef(class_results);

env->DeleteLocalRef(class_rect);

return true;

}

使用java层函数，即convertObjectTrackingResult：

jobject JNICameraContext::convertObjectTrackingResult(JNIEnv *env,camera_ex_msg_object_tracking_t* cb)

{

……

objecttracking_callback_cookie *c = &objectTrackingCookie;

if(NULL == c->results_clazz) {

ALOGD("%s:c->results_clazz is NULL;",__FUNCTION__ );

returnNULL;

}//获取使用ObjectTrackingResult类

jobjectcallbackObject = env->AllocObject(c->results_clazz); // create ObjectTrackingResult class

if(NULL == callbackObject) {

ALOGW("%s: object isNULL;",__FUNCTION__);

returnNULL;

}

// Create android.graphics.Rect object. //获取使用Rect类

jobjectrect_obj = env->AllocObject(c->rect_clazz);

if(NULL == rect_obj) {

ALOGW("%s Errorrect_obj = %p",__FUNCTION__,rect_obj);

returnNULL;

}

// Set rect data to android.graphics.Rect object.

env->CallVoidMethod(rect_obj,c->rect_set_mid, //使用类Rect的set方法

cb->rect[0], cb->rect[1], cb->rect[2],cb->rect[3]);

// Set android.graphics.Rect object to ObjectTrackingResult.Rect.

env->SetObjectField(callbackObject,c->mRectOfTrackedObject_fid,rect_obj);

env->DeleteLocalRef(rect_obj);//将数据传给javamRectOfTrackedObject变量

// Set isLost boolean to ObjectTrackingResult.boolean.

env->SetBooleanField(callbackObject, c->mIsLost_fid,cb->isLost);

if(mObjectObjectTrackingResult != NULL) {//将isloat信息传给java mIsLost变量

env->DeleteGlobalRef(mObjectObjectTrackingResult);

mObjectObjectTrackingResult = NULL;

}

mObjectObjectTrackingResult= env->NewGlobalRef(callbackObject);//结果返回

env->DeleteLocalRef(callbackObject);

returnmObjectObjectTrackingResult;

}

5.4 Client端数据处理

该函数会被service调用：

vim frameworks/av/camera/Camera.cpp

void Camera::dataCallback(int32_t msgType,const sp<IMemory>&dataPtr,

camera_frame_metadata_t *metadata)

{

sp<CameraListener> listener;

{

Mutex::Autolock_l(mLock);

listener = mListener; //listener会在jni中注册，下面分析

}

if(listener != NULL) { //调用jni postData函数将数据传至jni

listener->postData(msgType,dataPtr,metadata);

}

在jni中调用client接口设置listener：

client中设置listener接口函数：

void Camera::setListener(constsp<CameraListener>&listener) //在jni中被调用

{

Mutex::Autolock _l(mLock);

mListener =listener;

}

调用接口函数设置listener：

vimframeworks/base/core/jni/android_hardware_Camera.cpp

static jintandroid_hardware_Camera_native_setup(JNIEnv *env,jobject thiz,

jobject weak_this,jint cameraId,jint halVersion,jstringclientPackageName)

{

……

// We use a weak reference so the Camera object can be garbagecollected.

// The reference is only used as a proxy for callbacks.

sp<JNICameraContext>context = new JNICameraContext(env,weak_this, clazz, camera);

context->incStrong((void*)android_hardware_Camera_native_setup);

camera->setListener(context);

// save context in opaque field

env->SetLongField(thiz,fields.context,(jlong)context.get());

returnNO_ERROR;

}

5.5 Service端数据处理

vim./frameworks/av/services/camera/libcameraservice/api1/CameraClient.cpp

void CameraClient::handleObjectTracking(constsp<IMemory>& mem) {

……

if(c != NULL) {//调用clientdataCallback函数传输数据

c->dataCallback(CAMERA_MSG_OBJECT_TRACKING,mem,NULL);

LOG2("dataCallback left.top.right.bottom : %4d.%4d.%4d.%4d",

orgCb->rect[0], orgCb->rect[1],

orgCb->rect[2],orgCb->rect[3]);

}

再次用到callback机制：

声明callback函数：

void CameraClient::dataCallback(int32_t msgType,

constsp<IMemory>& dataPtr,camera_frame_metadata_t *metadata,void* user) {

LOG2("dataCallback(%d)",msgType);

sp<CameraClient> client =static_cast<CameraClient*>(getClientFromCookie(user).get());

if(client.get() == nullptr)return;

if(!client->lockIfMessageWanted(msgType))return;

if(dataPtr == 0&& metadata == NULL) {

ALOGE("Null datareturned in data callback");

client->handleGenericNotify(CAMERA_MSG_ERROR,UNKNOWN_ERROR,0);

return;

}

switch(msgType & ~CAMERA_MSG_PREVIEW_METADATA) {

……

caseCAMERA_MSG_OBJECT_TRACKING:

client->handleObjectTracking(dataPtr);

break;

/* MM-MC-SomcAddForSoMCAP-00+} */

default:

client->handleGenericData(msgType,dataPtr,metadata);

break;

}

调用hal接口函数注册callback函数：

status_t CameraClient::initialize(CameraModule *module) {

intcallingPid = getCallingPid();

status_t res;

……

charcamera_device_name[10];

snprintf(camera_device_name,sizeof(camera_device_name),"%d",mCameraId);

mHardware =new CameraHardwareInterface(camera_device_name);

res = mHardware->initialize(module);

if(res != OK) {

ALOGE("%s: Camera %d:unable to initialize device: %s (%d)",

__FUNCTION__,mCameraId,strerror(-res),res);

mHardware.clear();

returnres;

}

mHardware->setCallbacks(notifyCallback,

dataCallback,

dataCallbackTimestamp,

(void*)(uintptr_t)mCameraId);

// Enable zoom, error, focus, and metadata messages by default

enableMsgType(CAMERA_MSG_ERROR | CAMERA_MSG_ZOOM |CAMERA_MSG_FOCUS |

CAMERA_MSG_PREVIEW_METADATA| CAMERA_MSG_FOCUS_MOVE);

LOG1("CameraClient::initialize X (pid%d, id %d)",callingPid,mCameraId);

returnOK;

}

定义注册callabck接口函数：

vimframeworks/av/services/camera/libcameraservice/device1/CameraHardwareInterface.h

void setCallbacks(notify_callbacknotify_cb,

data_callbackdata_cb,

data_callback_timestampdata_cb_timestamp,

void*user)

{

mNotifyCb = notify_cb;

mDataCb = data_cb;

mDataCbTimestamp = data_cb_timestamp;

mCbUser = user;

ALOGV("%s(%s)",__FUNCTION__,mName.string());

if(mDevice->ops->set_callbacks) { //调用hardware层设置callback函数，类似，不做介绍

mDevice->ops->set_callbacks(mDevice,

__notify_cb,

__data_cb, //会调用mDataCb传递数据

__data_cb_timestamp,

__get_memory,

this);

}

转载请注明原文地址: https://ju.6miu.com/read-1299418.html

最新回复(0)