camera打开流程（preview）（APP->hal）

Cam1DeviceBase.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\device)

Cam1DeviceBase::onCam1Device_NotifyCb

接上章的 mpCamClient->startPreview() //开始使能Preview

 

Camera.java (packages\apps\legacycamera\src\com\android\camera)

onCreate

    mCameraPreviewThread.start(); //执行

Thread里面的run函数

 

Thread mCameraPreviewThread = new Thread(new Runnable() {

        public void run() {

            initializeCapabilities();   //单独分析1

            startPreview();   //单独分析2

        }

    });

 

 

 

initializeCapabilities //单独分析1

    //获取摄像头的一些参数，private android.hardware.Camera mCameraDevice;，所以这里会直接调用jni

    mInitialParams = mCameraDevice.getParameters();  

        //Camera.java (frameworks\base\core\java\android\hardware)

        Parameters p = new Parameters();

        String s = native_getParameters();

            //android_hardware_Camera.cpp (frameworks\base\core\jni)

             { "native_getParameters", "()Ljava/lang/String;", (void *)android_hardware_Camera_getParameters },

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

                    sp<Camera> camera = get_native_camera(env, thiz, NULL); //得到Camera的引用，Camera.cpp (frameworks\av\camera)

                String8 params8 = camera->getParameters(); //这里通过引用调用Camera.cpp里面相应的函数

                    //在Camera.cpp (frameworks\av\camera)

                    params = mCamera->getParameters(); //这里的mCamera就是open摄像头的时候得到camera的引用

                        //调用这里ICamera.cpp (frameworks\av\camera)

                        remote()->transact(GET_PARAMETERS, data, &reply); //通过binder从服务器端获取，单独分析3

    mFocusManager.initializeParameters(mInitialParams); 

 

 

 //开始预览，单独分析2

 startPreview();  

    setPreviewDisplay(mSurfaceHolder); //设置预览的画布

    setDisplayOrientation(); //设置显示方向

        mDisplayRotation = Util.getDisplayRotation(this);  //获得屏幕旋转值

        mDisplayOrientation = Util.getDisplayOrientation(mDisplayRotation, mCameraId); //获得屏幕方向

        mCameraDevice.setDisplayOrientation(mDisplayOrientation); //设置摄像头的屏幕方向
        mFaceView.setDisplayOrientation(mDisplayOrientation); //设置面对面的方向

    setCameraParameters(UPDATE_PARAM_ALL); //设置摄像头参数

        mParameters = mCameraDevice.getParameters(); //获取参数，单独分析1

        updateCameraParametersInitialize();  //更新参数

        mParameters.setPreviewFrameRate(max);

    // Inform the mainthread to go on the UI initialization.

    mCameraPreviewThread.notify(); //启动主线程进行UI初始化

    mCameraDevice.startPreview();

        //android_hardware_Camera.cpp (frameworks\base\core\jni)

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

        camera->startPreview()

            //Camera.cpp (frameworks\av\camera)

            sp <ICamera> c = mCamera;

            return c->startPreview(); //这里和get_parameters一个路径, 单独分析5

             

                

        

    

 

单独分析3：获取参数的服务端分析

    CameraHardwareInterface.h (frameworks\av\services\camera\libcameraservice\device1)

        char *temp = mDevice->ops->get_parameters(mDevice); //这里会调用到Cam1Device.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\device)的函数

            //Cam1Device.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\device)mtk_camera_device_ops数组中的get_parameters，加个一个前缀camera_get_parameters

            camera_get_parameters

                Cam1Device*const pDev = Cam1Device::getDevice(device); //获取设备

                param = pDev->getParameters();  //调用Cam1DeviceBase.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\device)

                String8 params_str8 = mpParamsMgr->flatten(); //获取参数 ，mutable MtkCameraParameters         mParameters;

                    //ParamsManager.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\common\paramsmgr\params)的flatten

                        mParameters.flatten(); //调用这个来获得参数

                            CameraParameters.cpp (frameworks\av\camera)  //获取参数键值对，赋值给字符串，返回

                            size_t size = mMap.size();   //map的值的来源，单独分析4

                            k = mMap.keyAt(i);

                            v = mMap.valueAt(i);

                strcpy(params_string, params_str8.string()); //把获得的参数拷贝到params_string

 

            

单独分析4：map的值的来源

ParamsManager.update.cpp(vendor\mediatek\proprietary\hardware\mtkcam\legacy\platform\mt6735\v1\common\paramsmgr\params)

updateDefaultParams1_ByDefaultS函数中设置默认的参数值，

    mParameters.set(CameraParameters::KEY_PREVIEW_FPS_RANGE, "5000,30000");

updatePreviewFpsParams函数中设置设置的参数值

    //s8FpsRangeDefault.string());这个值从config.ftbl.common_raw.h得到，具体分析看config.ftbl.common_raw.h分析这章

   mParameters.set(CameraParameters::KEY_PREVIEW_FPS_RANGE, s8FpsRangeDefault.string()); /

        //CameraParameters.cpp (frameworks\av\camera)中

        mMap.replaceValueFor(String8(key), String8(value));

 

 

单独分析5：开始预览的服务端分析

    CameraHardwareInterface.h (frameworks\av\services\camera\libcameraservice\device1)

startPreview

    return mDevice->ops->start_preview(mDevice);

        //Cam1Device.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\device)mtk_camera_device_ops数组中的get_parameters，加个一个前缀camera_get_parameters

        camera_start_preview

            Cam1Device*const pDev = Cam1Device::getDevice(device);

            err = pDev->startPreview();

            //Cam1DeviceBase.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\device)

                if  ( mpCamAdapter != 0 && mpCamAdapter->isTakingPicture() ) //判读是不是在拍照中

                    //MtkDefaultCamAdapter.Capture.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\platform\mt6735\v1\adapter\mtkdefault)

                    isTakingPicture

                    //IState::eState_PreCapture，IState::eState_Capture， IState::eState_PreviewCapture， IState::eState_VideoSnapshot，如果是这些状态就返回

                if  ( previewEnabled() ) //判断是否使能了preview，如果已经使能了，就返回

                if  ( ! onStartPreview() ) //开始预览，单独分析6

            enableDisplayClient()  //使能显示客户端，单独分析7

            mpCamClient->startPreview() //客户端开始使能预览，单独分析10

           // forward to registered clients

            Vector<sp<ICamClient> >::const_iterator it;

            for (it = vmpCamClient.begin(); it != vmpCamClient.end(); ++it)

                (*it)->startPreview();

            //  startPreview in Camera Adapter.

            status = mpCamAdapter->startPreview();

                MtkDefaultCamAdapter.Preview.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\platform\mt6735\v1\adapter\mtkdefault)

                mpStateManager->getCurrentState()->onStartPreview(this);

                    //StateManager.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\platform\mt6735\v1\adapter\mtkdefault\state)

                    return mpCurrState;

                    State.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\platform\mt6735\v1\adapter\mtkdefault\state)

                    onStartPreview

                        IStateManager::StateObserver stateWaiter(getStateManager());

                        getStateManager()->registerOneShotObserver(&stateWaiter);

                        status = pHandler->onHandleStopPreview();

                           // MtkDefaultCamAdapter.Preview.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\platform\mt6735\v1\adapter\mtkdefault)

                            return forceStopAndCleanPreview();

         enableMsgType(CAMERA_MSG_PREVIEW_METADATA); //Enable a message, or set of messages.

 

               

                    

 

单独分析6：开始预览

 if  ( ! onStartPreview() ) //开始预览，单独分析6

     //DefaultCam1Device.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\platform\mt6735\v1\device)

                    (0) wait for thread

                    waitThreadInitDone() //等待初始化线程完成

                    //  (1) Check Permission.

                    pCamMgr->getPermission()  //检查权限

                    // (2) Update Hal App Mode.

                    //ParamsManager.update.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\common\paramsmgr\params)

                    evaluateHalAppMode(s8HalAppMode)

                        return evaluateHalAppModeUtility(mode);

                            i4CamMode = mParameters.getInt(MtkCameraParameters::KEY_CAMERA_MODE); //获取模式，现在应该是CAMERA_MODE_MTK_PRV

                            pszZsdMode = mParameters.get(MtkCameraParameters::KEY_ZSD_MODE //获取是否是ZSD模式，如果是就

                            mode = MtkCameraParameters::APP_MODE_NAME_MTK_ZSD;

                    (3) Initialize Camera Adapter.

                    initCameraAdapter()

                        //  (1) Check to see if CamAdapter has existed or not. //如果不存在就创建一个

                        //  (2) Create & init a new CamAdapter.

                        mpCamAdapter = ICamAdapter::createInstance(mDevName, mi4OpenId, mpParamsMgr); //创建一个mpCamAdapter 

                            //BaseCamAdapter.Instance.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\platform\mt6735\v1\adapter)

                            s8AppMode = PARAMSMANAGER_MAP_INST(eMapAppMode)->stringFor(pParamsMgr->getHalAppMode()); //获得APP的模式

                            if  ( s8AppMode == MtkCameraParameters::APP_MODE_NAME_MTK_PHOTO )  //根据不同模式，生成不同的Adapter，这里以预览为例，后面又表格会说明什么情况生成什么Adapter

                                return  createMtkDefaultCamAdapter(s8AppMode, i4OpenId, pParamsMgr);  //单独分析7，生成Adapter，下章分析

 

                                

 

 

 

单独分析7：使能显示客户端

 enableDisplayClient() 

                [1] Get preview size.

                queryPreviewSize(previewSize.width, previewSize.height)  //获取预览大小

                    mpParamsMgr->getPreviewSize(&ri4Width, &ri4Height);

                            mParameters.getPreviewSize(width, height); 

                //  [2] Enable

                mpDisplayClient->enableDisplay(previewSize.width, previewSize.height, queryDisplayBufCount(), mpCamAdapter)

                    DisplayClient.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\client\displayclient)

                    preview_stream_ops* pStreamOps = mpStreamOps; //获取数据流的操作函数

                    //  [.1] uninitialize  //先清除

                    uninit();

                       disableDisplay();

                       destroyDisplayThread();

                       destroyImgBufQueue();

                    //  [.2] initialize

                    init()  //初始化

                        createDisplayThread

                            ret =   createDisplayThread() 

                               //DisplayClient.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\client\displayclient)

                               return  new DisplayThread(pHandler);

                                    DisplayThread::DisplayThread(IDisplayThreadHandler*const pHandler) : IDisplayThread()

       , mpThreadHandler(pHandler)   //线程执行函数

        , mi4Tid(0)

       , miLogLevel(1)

       , mCmdQue()  //数据流的操作命令

       , mCmdQueMtx()

       , mCmdQueCond()

mpDisplayThread->run()  //运行线程，关注threadLoop，会响应命令

    threadLoop 

        case Command::eID_WAKEUP:

        mpThreadHandler->onThreadLoop(cmd);  //单独分析8，onThreadLoop

                         createImgBufQueue()

                            mpImgBufQueue = new ImgBufQueue(IImgBufProvider::eID_DISPLAY, "CameraDisplay@ImgBufQue");  //创建缓存队列

                            mpExtImgProc = ExtImgProc::createInstance();

                //  [.3] set related window info.

                    setWindow(pStreamOps, i4Width, i4Height, i4BufCount)  //后续分析

                        set_preview_stream_ops(window, wndWidth, wndHeight, i4MaxImgBufCount);

                //  [.4] set Image Buffer Provider Client.

             //  [2] Enable.

                   enableDisplay() //使能输出

                       //  (2) Check to see if it has been enabled.

                       isDisplayEnabled()

                       //  (3) Check to see if thread is alive.

                       if  ( mpDisplayThread == 0 )

                       //  (4) Enable the flag.

                           ::android_atomic_write(1, &mIsDisplayEnabled);

                       //  (5) Post a command to wake up the thread.

                       mpDisplayThread->postCommand(Command(Command::eID_WAKEUP)); //这就是执行onThreadLoop    单独分析8

 

 

 //单独分析8，onThreadLoop

    //DisplayClient.BufOps.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\client\displayclient)

    //  (1) Prepare all TODO buffers.

    prepareAllTodoBuffers(pImgBufQueue)  //准备buf,单独分析9

    //  (2) Start

    pImgBufQueue->startProcessor()

        //ImgBufQueue.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\common\camutils)

        mbIsProcessorRunning = true;

       mDoneImgBufQueCond.broadcast(); //发送广播开始运行

    //  (3) Do until disabled.

        //  (.1)

        waitAndHandleReturnBuffers(pImgBufQueue);

           //  (1) deque buffers from processor.

            rpBufQueue->dequeProcessor(vQueNode);

            //  (2) handle buffers dequed from processor.

            ret = handleReturnBuffers(vQueNode);  //获得返回的BUf

                /*

     * Notes:

     *  For 30 fps, we just enque (display) the latest frame,

     *  and cancel the others.

     *  For frame rate > 30 fps, we should judge the timestamp here or source.

     */

    //  (1) determine the latest DONE buffer index to display; otherwise CANCEL.

    if  ( rvQueNode[idxToDisp].isDONE() )  //如果是30帧的数据

        break; //跳出

    //  (3) Remove from List and enquePrvOps/cancelPrvOps, one by one.

        //  (.1)  Check valid pointers to image buffers in Queue & List

        if  ( rpQueImgBuf == 0 || pStreamImgBuf == 0 )

            continue；

        //  (.2)  Check the equality of image buffers between Queue & List.

        if  ( rpQueImgBuf->getVirAddr() != pStreamImgBuf->getVirAddr() )

            continue;

        //  (.3)  Every check is ok. Now remove the node from the list.

            mStreamBufList.erase(mStreamBufList.begin());

        //  (.4)  enquePrvOps/cancelPrvOps

            IExtImgProc::ImgInfo img; //赋值图片的信息

            img.bufType     = ExtImgProc::BufType_Display;

            img.format      = pStreamImgBuf->getImgFormat();

            mpExtImgProc->doImgProc(img);

            // For Display Rotation

            if(rvQueNode[i].getOrientation() != 0)

                pStreamImgBuf->setNeedDisplayRotation(true);  //旋转

            enquePrvOps(pStreamImgBuf); //放入buf

                  

 

 

单独分析9：准备buf

       prepareOneTodoBuffer(rpBufQueue)

            //  (2) deque it from PrvOps

            sp<StreamImgBuf> pStreamImgBuf;

            dequePrvOps(pStreamImgBuf)

            //DisplayClient.BufOps.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\client\displayclient)

                //  [1] dequeue_buffer

                mpStreamOps->dequeue_buffer(mpStreamOps, &phBuffer, &stride);

                //  [3] Now let the graphics framework to lock the buffer, and provide us with the framebuffer data address.

                GraphicBufferMapper::get().lock(*phBuffer, CAMERA_GRALLOC_USAGE, bounds, &address);

                //  [4] Get the ion fd of gralloc buffer.

                err = ::gralloc_extra_query(*phBuffer, GRALLOC_EXTRA_GET_ION_FD, &fdIon);

                //  [5] Setup the output to return.

                rpImgBuf = new StreamImgBuf(mpStreamImgInfo, stride, address, phBuffer, fdIon);

        void* virtAddr = pStreamImgBuf->getVirAddr(); //得到虚拟地址

        if(pStreamImgBuf->getOrientation() & HAL_TRANSFORM_ROT_90) //如果是旋转90

            pStreamImgBuf->setNeedDisplayRotation(true);

            memset((void*)virtAddr, iFirstFrameColor, pStreamImgBuf->getBufSize());

        enquePrvOps(pStreamImgBuf); //放入bug

            //  [3] set timestamp.

            err = mpStreamOps->set_timestamp(mpStreamOps, rpImgBuf->getTimestamp());

            //  [5] unlocks and post the buffer to display.

            err = mpStreamOps->enqueue_buffer(mpStreamOps, rpImgBuf->getBufHndlPtr());

        //  (3) enque it into Processor

        ret = rpBufQueue->enqueProcessor(

            ImgBufQueNode(pStreamImgBuf, ImgBufQueNode::eSTATUS_TODO, 0, 0, 0, (uint32_t)mi4Orientation)

        );

         //  (4) enque it into List & increment the list size.

        mStreamBufList.push_back(pStreamImgBuf);

 

 

单独分析10，//客户端开始使能预览

mpCamClient->startPreview()

    mpFDClient->startPreview(); //启动人脸检测预览，没有什么工作

       //FDClient.h (vendor\mediatek\proprietary\hardware\mtkcam\legacy\platform\mt6735\v1\client\camclient\fd)

        return true;

    mpPreviewClient->startPreview()

        PreviewClient.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\client\camclient\previewcallback)

        :android_atomic_write(1, &mIsPrvStarted);

        ms8PrvTgtFmt = mpParamsMgr->getPreviewFormat(); //获取格式

            //ParamsManager.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\common\paramsmgr\params)

            getStr(CameraParameters::KEY_PREVIEW_FORMAT);

        mpParamsMgr->getPreviewSize(&mi4PrvWidth, &mi4PrvHeight); //得到预览尺寸

            mParameters.getPreviewSize(width, height);

        initBuffers();

            //PreviewClient.BufOps.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\client\camclient\previewcallback)

            //分配buf

            mpImgBufMgr = ImgBufManager::alloc(ms8PrvTgtFmt,  mi4PrvWidth, mi4PrvHeight, eMAX_PREVIEW_BUFFER_NUM, "PreviewClientCb", mpCamMsgCbInfo->mRequestMemory,  0,  0);

            mpExtImgProc = ExtImgProc::createInstance(); //创建IMG信息结构体，

                //ExtImgProcImp.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\common\extimgproc)

                return ExtImgProcImp::getInstance();

                    static ExtImgProcImp Singleton;

                        //Set which img buf you want to process.

      //For example: mImgMask = BufType_Display|BufType_Record;

       mImgMask = 0; //这里表示哪种BUF

       mUser = 0;  //user的个数

     mpExtImgProc->init();

         //ExtImgProcImp.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\common\extimgproc)

           android_atomic_inc(&mUser);  //用户加一

            onStateChanged();

                ////  enable if both preview started && message enabled; otherwise disable.

                if  ( isEnabledState() ) 

                    0 != ::android_atomic_release_load(&mIsMsgEnabled) &&  0 != ::android_atomic_release_load(&mIsPrvStarted)

                postCommand(Command(Command::eID_WAKEUP)); //启动线程PreviewClient.Thread.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\client\camclient\previewcallback)

                    threadLoop()

                        case Command::eID_WAKEUP:

                            onClientThreadLoop //单独分析11

 

 

//单独分析11：onClientThreadLoop

onClientThreadLoop 

    //  (1) Get references to pool/queue before starting, so that nothing will be free during operations.

    //  (2) stop & clear all buffers so that we won't deque any undefined buffer.

    pBufQueue->stopProcessor();

    //  (3) Prepare all TODO buffers.

    prepareAllTodoBuffers(pBufQueue, pBufMgr)

        //PreviewClient.BufOps.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\client\camclient\previewcallback)

        //  For better performance, we should enque all TODO buffers before starting.//  In that case, we could deque more than one buffers, and should enque //  them in the loop.

        //  (1) Determine how many buffers to enque.

        //  all buffers = callback buffers + enq buffers (in list) + not-enq buffers (others)

        //  Assumption:

        //  (1) callback is returned in order.

        //  (2) all callback are returned within this function,

        //      ==> not-enq buffers (others) = eMAX_PREVIEW_BUFFER_NUM - mImgBufList.size()

        iEnqCount = eMAX_PREVIEW_BUFFER_NUM - mImgBufList.size();

             //  (.1) Determine which buffer to enque.

            pCameraImgBuf = rpBufMgr->getBuf(muImgBufIdx);

            muImgBufIdx = (muImgBufIdx+1) % eMAX_PREVIEW_BUFFER_NUM;

            //  (.2) enque it into Processor

            ret = rpBufQueue->enqueProcessor( ImgBufQueNode(pCameraImgBuf, ImgBufQueNode::eSTATUS_TODO));

            //  (.3) enque it into List & increment the list size.

            mImgBufList.push_back(pCameraImgBuf);

    //  (4) Start

    pBufQueue->startProcessor()

    //  (5)   Do until all wanted messages are disabled.

    ::android_atomic_write(1, &mIsWaitBufBack);

        //  (.1)

        waitAndHandleReturnBuffers(pBufQueue); //等待BUF完成

            //PreviewClient.BufOps.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\client\camclient\previewcallback)

            //  (1) deque buffers from processor.

           rpBufQueue->dequeProcessor(vQueNode);

            //  (2) handle buffers dequed from processor.

           ret = handleReturnBuffers(vQueNode); //这个和//单独分析8，onThreadLoop一样

   mpRecordClient->startPreview()

        RecordClient.cpp (vendor\mediatek\proprietary\hardware\mtkcam\legacy\v1\client\camclient\record)

        if(mpParamsMgr->getInt(CameraParameters::KEY_PREVIEW_FRAME_RATE) > 30)

            mRecBufNum = 5 + (mpParamsMgr->getInt(CameraParameters::KEY_PREVIEW_FRAME_RATE)/30)*2 + 2; //获得buf的数量

        mpParamsMgr->set(MtkCameraParameters::KEY_VR_BUFFER_COUNT, mRecBufNum); //设置