Camera显示之Hal层的适配(二).doc

1、Camera 显示之 Hal 层的适配 (二 )Tag 标签：一 .基本关系 1. 先来看看 KTM hal 层大概类图关系：大概类图关系就是这样， 其中和显示相关的类图关系如红线所圈区域。可以猜测到与显示相关的逻辑处理应该都会在 DisplayClient这个类去实现。2.CamDeviceManager和 DisplayClient关系的建立：以后 app 下达有关预览显示相关的东西啊在hal 层基本上都是这一条先进行传递命令，不过总 1 中我们可以看到CamDevice还有一些衍生类，这些都是mtk 为不同设备做的一些定制，主要的路径还是如上图所示。二 .接着之前的在CameraClie

2、nt中的代码：/!+else if ( window = 0 ) result = mHardware->setPreviewWindow(window);1.setPreviewWindow(window)通过CameraHardwareInterface适配：mDevice->ops->set_preview_window(mDevice,buf.get() ? &mHalPreviewWindow.nw : 0);来实现向hal层下达命令和设置参数。在这里我们发现传入的是mHalPreviewWindow.nw， 而不是我们之前所讲述的 ANativeWindo

3、w这是因为 mHalPreviewWindow.nw将ANativeWindow的一些流的操作进行封装，使之操作更加简便。mHalPreviewWindow.nw的定义：structcamera_preview_window struct preview_stream_ops nw;void *user;就是结构体： struct：typedef struct preview_stream_ops int (*dequeue_buffer)(struct preview_stream_ops* w, buffer_handle_t* buffer, int *stride);int (*enq

4、ueue_buffer)(struct preview_stream_ops* w, buffer_handle_t* buffer);int (*cancel_buffer)(struct preview_stream_ops* w, buffer_handle_t* buffer);int (*set_buffer_count)(struct preview_stream_ops* w, int count);int (*set_buffers_geometry)(structpreview_stream_ops* pw,int w, int h, int format);int (*se

5、t_crop)(struct preview_stream_ops *w, int left, int top, int right, int bottom);int (*set_usage)(struct preview_stream_ops* w, int usage);int (*set_swap_interval)(struct preview_stream_ops *w, int interval);int (*get_min_undequeued_buffer_count)(const struct preview_stream_ops *w,int *count);int (*l

6、ock_buffer)(struct preview_stream_ops* w, buffer_handle_t* buffer);/ Timestamps are measured in nanoseconds, and must be comparable/ and monotonically increasing between two frames in the same/ preview stream. They do not need to be comparable between/ consecutive or parallel preview streams, camera

7、s, or app (*set_timestamp)(struct preview_stream_ops *w, int64_t timestamp);对显示流的操作都是通过这些函数实现的，而mHalPreviewWindow中实现了具体操的方法，在这些方法的实现中实现对作ANativeWindow的操作。而在 hal 端就是通过mHalPreviewWindow.nw进行对ANativeWindow的具体操作。基本类图关系：2. 继续1 中的：mDevice->ops->set_preview_window(mDevice,buf.get() ? &mH

8、alPreviewWindow.nw : 0);我已经知道了mHalPreviewWindow.nw为传入的一个重要参数mHalPreviewWindow.nw为preview_stream_ops。继续看看 set_preview_window这个方法。我们有上篇文章知道 ops 是 ICamDevice的一个成员gCameraDevOps，类型为 camera_device_ops_t：可以看到：staticcamera_device_ops_t const gCameraDevOps = set_preview_window:camera_set_preview_window,set_c

9、allbacks:camera_set_callbacks,enable_msg_type:camera_enable_msg_type,disable_msg_type:camera_disable_msg_type,msg_type_enabled:camera_msg_type_enabled,start_preview:camera_start_preview,stop_preview:camera_stop_preview,preview_enabled:camera_preview_enabled,store_meta_data_in_buffers:camera_store_me

10、ta_data_in_buffers,start_recording: camera_start_recording, stop_recording:camera_stop_recording,recording_enabled:camera_recording_enabled,release_recording_frame:camera_release_recording_frame,auto_focus: camera_auto_focus, cancel_auto_focus:camera_cancel_auto_focus,take_picture:camera_take_pictur

11、e,cancel_picture: camera_cancel_picture, set_parameters:camera_set_parameters,get_parameters:camera_get_parameters,put_parameters:camera_put_parameters,send_command:camera_send_command,release:camera_release,dump:camera_dump,;gCameraDevOps中的函数地址映射到ICamDevice中的函数实现。所以：ops->set_preview_window(mDevi

12、ce, buf.get() ?&mHalPreviewWindow.nw : 0)就对应到ICamDevice:camera_set_preview_window的发发调用。static int camera_set_preview_window(struct camera_device * device,struct preview_stream_ops *window)int err = -EINVAL;/ICamDevice*const pDev =ICamDevice:getIDev(device);if( pDev )err = pDev->setPreviewWind

13、ow(window);/returnerr;static inline ICamDevice*getIDev(camera_device*constdevice)return (NULL = device)NULL: reinterpret_cast(device->priv);/得到device->priv由上篇文章：知道device->pri实际上是在创建实例的时候指向的自己：ICamDevice:ICamDevice(): camera_device_t() , RefBase(), mDevOps()/, mMtxLock()/MY_LOGD('ctor

14、9;); :memset(static_cast(this), 0,sizeof(camera_device_t);this->priv= this; /用priv指针保存自己。this->ops= &mDevOps;/ops指向了mDevOpsmDevOps= gCameraDevOps;/mDevOps为gCameraDevOps指向的结构体继续回到pDev->setPreviewWindow(window);在ICamDevice中没有对setPreviewWindow具体的实现，而是在其子类CamDevice对ICamDevice进行了具体的实现;随意代码定位

15、到CamDevice ： status_tCamDevice:setPreviewWindow(preview_stream_ops* window)MY_LOGI('+ window(%p)', window);/status_t status = initDisplayClient(window);/开始初始化 DisplayClientif ( OK = status && previewEnabled() && mpDisplayClient != 0 )status = enableDisplayClient();/时能 Display

16、Client端/returnstatus;status_tCamDevice:initDisplayClient(preview_stream_ops* window)#if '1'!=MTKCAM_HAVE_DISPLAY_CLIENT#warning 'Not Build Display Client'MY_LOGD('Not Build Display Client');./ 3.1 create a Display Client.mpDisplayClient = IDisplayClient:createInstance(); if (

17、 mpDisplayClient = 0 )MY_LOGE('Cannot create mpDisplayClient'); status = NO_MEMORY; goto lbExit;/ 3.2 initialize the newly-created Display Client.if( ! mpDisplayClient->init() )MY_LOGE('mpDisplayClient init() failed'); mpDisplayClient->uninit(); mpDisplayClient.clear(); status

18、= NO_MEMORY;goto lbExit;/ 3.3 set preview_stream_ops & related windowinfo.if ( ! mpDisplayClient->setWindow(window, previewSize.width, previewSize.height, queryDisplayBufCount() )/ 绑定 windowstatus = INVALID_OPERATION;goto lbExit;/ 3.4 set Image Buffer Provider Client if it exist.if ( mpCamAda

19、pter != 0 && ! mpDisplayClient->setImgBufProviderClient(mpCamAdapter) )/ 重要！ 设置流数据的 Buffer 提供者。status = INVALID_OPERATION; goto lbExit;.status_tCamDevice:enableDisplayClient()status_t status = OK;Size previewSize;/ 1 Get preview size.if ( ! queryPreviewSize(previewSize.width, previewSize.

20、height) )MY_LOGE('queryPreviewSize');status = DEAD_OBJECT;goto lbExit;/ 2 Enableif( !mpDisplayClient->enableDisplay(previewSize.width,previewSize.height, queryDisplayBufCount(),mpCamAdapter) )/设置了预览数据的尺寸和Buffer 提供者相关的数据MY_LOGE('mpDisplayClient(%p)->enableDisplay()', mpDisplayCl

21、ient.get();status = INVALID_OPERATION;goto lbExit;/status = OK;lbExit:returnstatus;3.定位到 DisplayClient 中： int32_t const i4Width, int32_t const i4Height, int32_t const i4BufCount, spconst& rpClientenableDisplay()bool ret = false;preview_stream_ops* pStreamOps = mpStreamOps;/ 1 Re-configurate this

22、 instance if any setting changes.if ( ! checkConfig(i4Width, i4Height, i4BufCount, rpClient) )MY_LOGW(' Uninit the current DisplayClient(%p) and re-config.', this);/ .1 uninitialize uninit();/ .2 initializeif( ! init() )MY_LOGE('re-init() failed');goto lbExit;/ .3 set related window

23、info.if( ! setWindow(pStreamOps, i4Width, i4Height,i4BufCount) )/window的尺寸和预览数据的大小一致goto lbExit;/ .4 set Image Buffer Provider Client.if( ! setImgBufProviderClient(rpClient) )/Buffer的数据提供者为mpCamAdapter， 就是CamAdapter， 后面的预览数据元都是通过它来提供。goto lbExit;/2 Enable.if( ! enableDisplay() )/开始进行数据的获取和显示goto lbE

24、xit;/ret = true;lbExit:returnret;先来看看第一个关键函数：setWindow(pStreamOps,i4Width, i4Height, i4BufCount)boolDisplayClient:setWindow(preview_stream_ops*const window,int32_t constwndWidth,int32_t constwndHeight,int32_t consti4MaxImgBufCount)MY_LOGI('+ window(%p), WxH=%dx%d, count(%d)', window, wndWidt

25、h, wndHeight, i4MaxImgBufCount);/if( ! window )MY_LOGE('NULL window passed into');returnfalse;/if( 0 >= wndWidth | 0 >= wndHeight | 0 >=i4MaxImgBufCount )MY_LOGE('bad arguments - WxH=%dx%d,count(%d)', wndWidth, wndHeight, i4MaxImgBufCount);returnfalse;/Mutex:Autolock _l(mMod

26、uleMtx);returnset_preview_stream_ops(window, wndWidth,wndHeight, i4MaxImgBufCount);/oolDisplayClient:set_preview_stream_ops(preview_stream_ops*const window,int32_t constwndWidth,int32_t constwndHeight,int32_t consti4MaxImgBufCount)CamProfile profile(_FUNCTION_, 'DisplayClient');/boolret = fa

27、lse;status_terr = 0;int32_tmin_undequeued_buf_count = 0;/ (2) Checkif( ! mStreamBufList.empty() )/MY_LOGE('locked buffer count(%d)!=0, ''callers must return all dequeued buffers, ''and then call cleanupQueue()', mStreamBufList.size();dumpDebug(mStreamBufList, _FUNCTION_);goto

28、 lbExit;/(3) Sava info.mpStreamImgInfo.clear();/mpStreamImgInfo封装的视屏数据流的基本信息。mpStreamImgInfo= new ImgInfo(wndWidth,wndHeight, CAMERA_DISPLAY_FORMAT,CAMERA_DISPLAY_FORMAT_HAL,'CameraDisplay');/设置了 Stream 的宽高和显示类型。mpStreamOps= window;/mpStreamOps保存了上层传进来的对象指针。后面就通过它和显示方进行交互。mi4MaxImgBufCount .

29、= i4MaxImgBufCount;.err = mpStreamOps->set_buffer_count(mpStreamOps, mi4MaxImgBufCount+min_undequeued_buf_count);if( err )MY_LOGE('set_buffer_count failed:status%s(%d)', :strerror(-err), -err);if ( ENODEV = err )MY_LOGD('Preview surface abandoned!'); mpStreamOps = NULL; goto lbExi

30、t;/ (4.4) Set window geometryerr = mpStreamOps->set_buffers_geometry(/设置基本的流信息mpStreamOps,mpStreamImgInfo->mu4ImgWidth,mpStreamImgInfo->mu4ImgHeight,mpStreamImgInfo->mi4ImgFormat);通过上面的代码片段和分析，确定了上层传递下来的对象指针保存在mpStreamOps， 与显示相关的交互都将通过mpStreamOps来进行操作。而 mpStreamImgInfo封装了流数据的大小和格式等。再来看看第

31、二个关键函数：setImgBufProviderClient(rpClient)： boolDisplayClient:setImgBufProviderClient(spconst& rpClient)bool ret = false;/MY_LOGD('+ ImgBufProviderClient(%p),mpImgBufQueue.get(%p)', rpClient.get(),mpImgBufQueue.get();/if( rpClient = 0 )MY_LOGE('NULL ImgBufProviderClient'); mpImgBuf

32、PvdrClient = NULL; goto lbExit;/if( mpImgBufQueue != 0 )if( !rpClient->onImgBufProviderCreated(mpImgBufQueue) )/通知 Provider 端 (Buffer 数据提供者端 )，我这边已经建好Buffer 队列， 后面你就填充数据到对应的Buffer 供我使用。goto lbExit;mpImgBufPvdrClient = rpClient;/用mpImgBufPvdrClient保存 provider 的对象指针， 方便使用。/ret = true;lbExit:MY_LOGD

33、('-');returnret;再来看看第三个关键函数enableDisplay()：boolDisplayClient:enableDisplay()bool ret = false;/ (1) Lock/MY_LOGD('+ isDisplayEnabled(%d), mpDisplayThread.get(%p)', isDisplayEnabled(), mpDisplayThread.get();/ (2) Check to see if it has been enabled.if( isDisplayEnabled() )MY_LOGD('

34、Display is already enabled');ret = true;goto lbExit;/ (3) Check to see if thread is alive.if( mpDisplayThread = 0 )MY_LOGE('NULL mpDisplayThread');goto lbExit;/ (4) Enable the flag.:android_atomic_write(1, &mIsDisplayEnabled);/ (5) Post a command to wake up the thread.mpDisplayThread

35、->postCommand(Command(Command:eID_WAKEUP);/通知获取数据的线程开始运行/ret = true;lbExit:MY_LOGD('- ret(%d)', ret);return ret;boolDisplayThread:threadLoop()Command cmd;if( getCommand(cmd) )switch(cmd.eId)case Command:eID_EXIT:MY_LOGD('Command:%s', ();break;/case Command:eID_WAKEUP:/ 对应上

36、面发送的命令 default:if( mpThreadHandler != 0 )mpThreadHandler->onThreadLoop(cmd);/注意此处，mpThreadHandler 就是 DisplayClient( 它继承了 IDisplayThreadHandler) ，elseMY_LOGE('cannot handle cmd(%s) due to mpThreadHandler=NULL', ();break;/MY_LOGD('- mpThreadHandler.get(%p)', mpThreadHandler.

37、get();returntrue;回到 DisplayClient的 onThreadLoop函数：boolDisplayClient:onThreadLoop(Command const& rCmd)/ (0) lock Processor.sp pImgBufQueue;Mutex:Autolock _l(mModuleMtx);pImgBufQueue = mpImgBufQueue;if( pImgBufQueue = 0 | ! isDisplayEnabled() )/判断显示相关的初始化是否完成和启动MY_LOGW('pImgBufQueue.get(%p), i

38、sDisplayEnabled(%d)', pImgBufQueue.get(), isDisplayEnabled();returntrue;/ (1) Prepare all TODO buffers.if( ! prepareAllTodoBuffers(pImgBufQueue) )/为pImgBufQueue添加空 Buffer 。returntrue;/(2) Startif( ! pImgBufQueue->startProcessor() )/开始获取数据returntrue;/Mutex:Autolock _l(mStateMutex);mState = eSt

39、ate_Loop;mStateCond.broadcast();/ (3) Do until disabled.while( 1 )/ 进入无限循环/ (.1)waitAndHandleReturnBuffers(pImgBufQueue);/等待pImgBufQueue中的数据 ,并送到显示端显示/ (.2) break if disabled.if( ! isDisplayEnabled() )MY_LOGI('Display disabled');break;/ (.3) re-prepare all TODO buffers, if possible,/ since s

40、ome DONE/CANCEL buffers return.prepareAllTodoBuffers(pImgBufQueue);/又重新准备Buffer 。/ (4) StoppImgBufQueue->pauseProcessor(); pImgBufQueue->flushProcessor(); pImgBufQueue->stopProcessor();/ 停止数据获取 / (5) Cancel all un-returned buffers.cancelAllUnreturnBuffers();/没有来得及显示额数据，也取消掉。/Mutex:Autolock

41、_l(mStateMutex);mState = eState_Suspend;mStateCond.broadcast();/returntrue;上边这个代码片段对预览数据的处理就在waitAndHandleReturnBuffers(pImgBufQueue);中。4. 对 waitAndHandleReturnBuffers(pImgBufQueue);进行分析：boolDisplayClient:waitAndHandleReturnBuffers(spconst& rpBufQueue)bool ret = false;Vector vQueNode;/MY_LOGD_IF

42、(1/(1) deque buffers from processor.rpBufQueue->dequeProcessor(vQueNode);/从provider 端（数据提供端）获取一个填充数据了的Buffer。if( vQueNode.empty() ) MY_LOGW('vQueNode.empty()');goto lbExit;/(2) handle buffers dequed from processor.ret = handleReturnBuffers(vQueNode);/处理填充了数据的这个 Buffer 中的数据。lbExit:/MY_LOGD

43、_IF(2return ret;看看 handleReturnBuffers 函数：boolDisplayClient:handleReturnBuffers(Vectorconst& rvQueNode)/* 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 DO

44、NE buffer index to display; otherwise CANCEL.int32_t idxToDisp = 0;for ( idxToDisp = rvQueNode.size()-1; idxToDisp >= 0;idxToDisp-)if( rvQueNodeidxToDisp.isDONE() )break;if( rvQueNode.size() > 1 )MY_LOGW('(%d) display frame count > 1 -> select %d to display', rvQueNode.size(), id

45、xToDisp);/ Show Time duration.if( 0nsecs_t const _timestamp1 = rvQueNodeidxToDisp.getImgBuf()->getTimestamp();mProfile_buffer_timestamp.pulse(_timestamp1); nsecs_t const _msDuration_buffer_timestamp= :ns2ms(mProfile_buffer_timestamp.getDuration(); mProfile_buffer_timestamp.reset(_timestamp1);/mProfile_d