AndroidO Camera 分析（一）： (API 2)openCamera 流程
16lz
2021-01-24
AndroidO Camera 分析（一）： (API 2)openCamera 流程
相关的文件如下：
- frameworks/base/core/java/android/hardware/camera2/CameraManager.java
1、Java 层
- frameworks/base/core/java/android/hardware/camera2/CameraManager.java
- frameworks/base/core/java/android/hardware/camera2/impl/CameraDeviceImpl.java
/* CameraManager.java */public void openCamera(@NonNull String cameraId, @NonNull final CameraDevice.StateCallback callback, @Nullable Handler handler) throws CameraAccessException { /* 接着分析 */ openCameraForUid(cameraId, callback, handler, USE_CALLING_UID);}/* CameraManager.java */public void openCameraForUid(@NonNull String cameraId, @NonNull final CameraDevice.StateCallback callback, @Nullable Handler handler, int clientUid) throws CameraAccessException { if (handler == null) { /* looper handle 机制， 没什么好说的 */ if (Looper.myLooper() != null) { handler = new Handler(); } else { throw new IllegalArgumentException( "Handler argument is null, but no looper exists in the calling thread"); } } /* 接着分析 */ openCameraDeviceUserAsync(cameraId, callback, handler, clientUid);}/* CameraManager.java */private CameraDevice openCameraDeviceUserAsync(String cameraId, CameraDevice.StateCallback callback, Handler handler, final int uid) throws CameraAccessException { /* 获得 camera 的信息，这个函数会使用 CameraService binder 服务来得到信息 */ CameraCharacteristics characteristics = getCameraCharacteristics(cameraId); CameraDevice device = null; synchronized (mLock) { ICameraDeviceUser cameraUser = null; /* new CameraDeviceImpl */ android.hardware.camera2.impl.CameraDeviceImpl deviceImpl = new android.hardware.camera2.impl.CameraDeviceImpl( cameraId, callback, handler, characteristics, mContext.getApplicationInfo().targetSdkVersion); /* * 获得回调， 这个回调很重要 * 处理好的图像帧会通过这个回调传回上层 */ ICameraDeviceCallbacks callbacks = deviceImpl.getCallbacks(); try { if (supportsCamera2ApiLocked(cameraId)) { /* 获得 CameraService binder 服务 */ ICameraService cameraService = CameraManagerGlobal.get().getCameraService(); /* * RPC 跨进程调用 cameraService::connectDevice * 看后面 C/C++ 层分析 */ cameraUser = cameraService.connectDevice(callbacks, cameraId, mContext.getOpPackageName(), uid); } } catch (ServiceSpecificException e) { ...... } catch (RemoteException e) { ...... } /* * cameraUser 由 cameraService.connectDevice() 得到 * 接着分析 */ deviceImpl.setRemoteDevice(cameraUser); device = deviceImpl; } return device;}/* CameraDeviceImpl.java */public void setRemoteDevice(ICameraDeviceUser remoteDevice) throws CameraAccessException { synchronized(mInterfaceLock) { /* remoteDevice 由 cameraService.connectDevice() 得到 */ mRemoteDevice = new ICameraDeviceUserWrapper(remoteDevice); IBinder remoteDeviceBinder = remoteDevice.asBinder(); if (remoteDeviceBinder != null) { try { /* 连接死亡通知， 当服务时挂掉会通知 */ remoteDeviceBinder.linkToDeath(this, /*flag*/ 0); } catch (RemoteException e) { ...... } } /* * mCallOnOpened 在本文件中定义，如下 * 所以显然就是调用 mCallOnOpened.run() */ mDeviceHandler.post(mCallOnOpened); /* mCallOnUnconfigured 在本文件中定义，如下 */ mDeviceHandler.post(mCallOnUnconfigured); }}/* CameraDeviceImpl.java */private final Runnable mCallOnOpened = new Runnable() { public void run() { StateCallbackKK sessionCallback = null; synchronized(mInterfaceLock) { sessionCallback = mSessionStateCallback; } if (sessionCallback != null) { sessionCallback.onOpened(CameraDeviceImpl.this); } /* mDeviceCallback 就是 APP 调用openCamera()时传入的第二个参数 * 所以这个回调是回调回应用程序 * 之后应用程序使用 CameraDeviceImpl 操作相机 */ mDeviceCallback.onOpened(CameraDeviceImpl.this); }};/* CameraDeviceImpl.java */private final Runnable mCallOnUnconfigured = new Runnable() { @Override public void run() { StateCallbackKK sessionCallback = null; synchronized(mInterfaceLock) { if (mRemoteDevice == null) return; // Camera already closed sessionCallback = mSessionStateCallback; } if (sessionCallback != null) { sessionCallback.onUnconfigured(CameraDeviceImpl.this); } }};2、C/C++ 层
- frameworks/av/services/camera/libcameraservice/CameraService.cpp
上面分析得知，Java 层中会通过 binder 跨进程调用 CameraService::connectDevice()
/* CameraService.cpp */Status CameraService::connectDevice( const sp& cameraCb, const String16& cameraId, const String16& clientPackageName, int clientUid, /*out*/ sp* device) { Status ret = Status::ok(); String8 id = String8(cameraId); sp client = nullptr; /* 接着分析 */ ret = connectHelper(cameraCb, id, CAMERA_HAL_API_VERSION_UNSPECIFIED, clientPackageName, clientUid, USE_CALLING_PID, API_2, /*legacyMode*/ false, /*shimUpdateOnly*/ false, /*out*/client); *device = client; return ret;}/* * CameraService.cpp * CALLBACK = hardware::camera2::ICameraDeviceCallbacks * CLIENT = CameraDeviceClient */template<class CALLBACK, class CLIENT>Status CameraService::connectHelper(const sp& cameraCb, const String8& cameraId, int halVersion, const String16& clientPackageName, int clientUid, int clientPid, apiLevel effectiveApiLevel, bool legacyMode, bool shimUpdateOnly, /*out*/sp& device) { binder::Status ret = binder::Status::ok(); String8 clientName8(clientPackageName); int originalClientPid = 0; /* CLIENT = CameraDeviceClient */ sp client = nullptr; { mFlashlight->prepareDeviceOpen(cameraId); int facing = -1; int deviceVersion = getDeviceVersion(cameraId, /*out*/&facing); sp tmp = nullptr; /* makeClient() 很重要， 后面分析 */ if(!(ret = makeClient(this, cameraCb, clientPackageName, cameraId, facing, clientPid, clientUid, getpid(), legacyMode, halVersion, deviceVersion, effectiveApiLevel, /*out*/&tmp)).isOk()) { return ret; } /* 转换 CLIENT = CameraDeviceClient */ client = static_cast(tmp.get()); /* * 分析完 makeClient 知道 client 是 CameraDeviceClient 对象 * 所以是调用 CameraDeviceClient::initialize() ，后面分析 * mCameraProviderManager = new CameraProviderManager() */ err = client->initialize(mCameraProviderManager); device = client; return ret;}/* CameraService.cpp */Status CameraService::makeClient(const sp& cameraService, const sp& cameraCb, const String16& packageName, const String8& cameraId, int facing, int clientPid, uid_t clientUid, int servicePid, bool legacyMode, int halVersion, int deviceVersion, apiLevel effectiveApiLevel, /*out*/sp* client) { if (halVersion < 0 || halVersion == deviceVersion) { switch(deviceVersion) { ...... break; case CAMERA_DEVICE_API_VERSION_3_0: case CAMERA_DEVICE_API_VERSION_3_1: case CAMERA_DEVICE_API_VERSION_3_2: case CAMERA_DEVICE_API_VERSION_3_3: case CAMERA_DEVICE_API_VERSION_3_4: if (effectiveApiLevel == API_1) { // Camera1 API route sp tmp = static_cast(cameraCb.get()); *client = new Camera2Client(cameraService, tmp, packageName, cameraIdToInt(cameraId), facing, clientPid, clientUid, servicePid, legacyMode); } else { // Camera2 API route /* 我们只分析 Camera2 */ sp tmp = static_cast(cameraCb.get()); /* * 这个很重要，new CameraDeviceClient() * 接着分析 CameraDeviceClient() 构造函数 */ *client = new CameraDeviceClient(cameraService, tmp, packageName, cameraId, facing, clientPid, clientUid, servicePid); } break; default: } } else { ...... } return Status::ok();}/* CameraDeviceClient.cpp */CameraDeviceClient::CameraDeviceClient(const sp& cameraService, const sp& remoteCallback, const String16& clientPackageName, const String8& cameraId, int cameraFacing, int clientPid, uid_t clientUid, int servicePid) : /* 接着分析 */ Camera2ClientBase(cameraService, remoteCallback, clientPackageName, cameraId, cameraFacing, clientPid, clientUid, servicePid), mInputStream(), mStreamingRequestId(REQUEST_ID_NONE), mRequestIdCounter(0), mPrivilegedClient(false) { char value[PROPERTY_VALUE_MAX]; property_get("persist.camera.privapp.list", value, ""); String16 packagelist(value); if (packagelist.contains(clientPackageName.string())) { mPrivilegedClient = true; } ATRACE_CALL(); ALOGI("CameraDeviceClient %s: Opened", cameraId.string());}/* Camera2ClientBase.cpp */template <typename TClientBase>Camera2ClientBase::Camera2ClientBase( const sp& cameraService, const sp& remoteCallback, const String16& clientPackageName, const String8& cameraId, int cameraFacing, int clientPid, uid_t clientUid, int servicePid): TClientBase(cameraService, remoteCallback, clientPackageName, cameraId, cameraFacing, clientPid, clientUid, servicePid), mSharedCameraCallbacks(remoteCallback), mDeviceVersion(cameraService->getDeviceVersion(TClientBase::mCameraIdStr)), mDeviceActive(false){ ALOGI("Camera %s: Opened. Client: %s (PID %d, UID %d)", cameraId.string(), String8(clientPackageName).string(), clientPid, clientUid); mInitialClientPid = clientPid; /* 这个对象很重要 */ mDevice = new Camera3Device(cameraId); LOG_ALWAYS_FATAL_IF(mDevice == 0, "Device should never be NULL here.");}/* CameraDeviceClient.cpp */status_t CameraDeviceClient::initialize(sp manager) { return initializeImpl(manager);}/* TProviderPtr = CameraProviderManager */template<typename TProviderPtr>status_t CameraDeviceClient::initializeImpl(TProviderPtr providerPtr) { ATRACE_CALL(); status_t res; /* 接着分析 */ res = Camera2ClientBase::initialize(providerPtr); if (res != OK) { return res; } String8 threadName; /* 处理图像帧的实例 */ mFrameProcessor = new FrameProcessorBase(mDevice); threadName = String8::format("CDU-%s-FrameProc", mCameraIdStr.string()); /* 进入一个线程循环处理图像帧 */ mFrameProcessor->run(threadName.string()); mFrameProcessor->registerListener(FRAME_PROCESSOR_LISTENER_MIN_ID, FRAME_PROCESSOR_LISTENER_MAX_ID, /*listener*/this, /*sendPartials*/true); return OK;}template <typename TClientBase>status_t Camera2ClientBase::initialize(sp manager) { /* 接着分析 */ return initializeImpl(manager);}template <typename TClientBase>template <typename TProviderPtr>status_t Camera2ClientBase::initializeImpl(TProviderPtr providerPtr) { /* * mDevice 就是 Camera3Device 对象 * 所以就是调用 Camera3Device::initialize() */ res = mDevice->initialize(providerPtr); wp weakThis(this); res = mDevice->setNotifyCallback(weakThis); return OK;}/* Camera3Device.cpp */status_t Camera3Device::initialize(sp manager) { ATRACE_CALL(); Mutex::Autolock il(mInterfaceLock); Mutex::Autolock l(mLock); sp session; ATRACE_BEGIN("CameraHal::openSession"); /* * manager 就是 CameraProviderManager 对象 * 所以就是调用 CameraProviderManager::openSession() */ status_t res = manager->openSession(mId.string(), this, /*out*/ &session); ATRACE_END(); res = manager->getCameraCharacteristics(mId.string(), &mDeviceInfo); std::shared_ptr queue; auto requestQueueRet = session->getCaptureRequestMetadataQueue( [&queue](const auto& descriptor) { queue = std::make_shared(descriptor); if (!queue->isValid() || queue->availableToWrite() <= 0) { ALOGE("HAL returns empty request metadata fmq, not use it"); queue = nullptr; // don't use the queue onwards. } }); std::unique_ptr& resQueue = mResultMetadataQueue; auto resultQueueRet = session->getCaptureResultMetadataQueue( [&resQueue](const auto& descriptor) { resQueue = std::make_unique(descriptor); if (!resQueue->isValid() || resQueue->availableToWrite() <= 0) { ALOGE("HAL returns empty result metadata fmq, not use it"); resQueue = nullptr; // Don't use the resQueue onwards. } }); mInterface = new HalInterface(session, queue); std::string providerType; mVendorTagId = manager->getProviderTagIdLocked(mId.string()); /* 这个函数里面会启动请求队列线程， 后面分析 */ return initializeCommonLocked();}/* CameraProviderManager.cpp */status_t CameraProviderManager::openSession(const std::string &id, const sp& callback, /*out*/ sp *session) { std::lock_guard<std::mutex> lock(mInterfaceMutex); auto deviceInfo = findDeviceInfoLocked(id, /*minVersion*/ {3,0}, /*maxVersion*/ {4,0}); auto *deviceInfo3 = static_cast(deviceInfo); Status status; hardware::Return<void> ret; /* * mInterface 它实际上是 CameraDevice 对象 * 所以就是调用 CameraDevice::open() */ ret = deviceInfo3->mInterface->open(callback, [&status, &session] (Status s, const sp& cameraSession) { status = s; if (status == Status::OK) { *session = cameraSession; } }); return mapToStatusT(status);}/* CameraDevice.cpp */Return<void> CameraDevice::open(const sp& callback, open_cb _hidl_cb) { Status status = initStatus(); sp session = nullptr; /** Open HAL device */ status_t res; camera3_device_t *device; ATRACE_BEGIN("camera3->open"); /* * mModule 是 CameraModule 对象 * 所以调用 CameraModule::open() *这里最后会调用 HAL 层的 open() 函数， 后面分析 */ res = mModule->open(mCameraId.c_str(), reinterpret_cast(&device)); ATRACE_END(); struct camera_info info; res = mModule->getCameraInfo(mCameraIdInt, &info); session = createSession( device, info.static_camera_characteristics, callback); mSession = session; mLock.unlock(); } _hidl_cb(status, session->getInterface()); return Void();}/* CameraModule.cpp */int CameraModule::open(const char* id, struct hw_device_t** device) { int res; ATRACE_BEGIN("camera_module->open"); /* * 这里的 mModule 是 hw_get_module 得到的，注意别被名字混淆了 * 最终会调用 HAL 层 open() 得到 device */ res = filterOpenErrorCode(mModule->common.methods->open(&mModule->common, id, device)); ATRACE_END(); return res;} 写到这里发现实在有太多的细节没有办法一一的介绍到，下面我会放上我分析代码的笔记，感兴趣的可以看看
3 笔记
3.1 《openCamera 流程》
《openCamera 流程》frameworks/base/core/java/android/hardware/camera2/CameraManager.javaopenCamera()--->openCameraForUid(cameraId, callback, handler, USE_CALLING_UID); --->handler = new Handler(); --->openCameraDeviceUserAsync(cameraId, callback, handler, clientUid); --->getCameraCharacteristics(cameraId); //获得camera的一些特征 --->ICameraService cameraService = CameraManagerGlobal.get().getCameraService(); //获得 CameraService binder 服务。参考《CameraService 守护进程分析》 --->CameraMetadataNative info = cameraService.getCameraCharacteristics(cameraId); //通过binder调用到 CameraService.cpp 的getCameraCharacteristics函数 --->characteristics = new CameraCharacteristics(info); //构造特征 --->deviceImpl = new android.hardware.camera2.impl.CameraDeviceImpl(cameraId, callback, handler, characteristics, mContext.getApplicationInfo().targetSdkVersion); --->mCameraId = cameraId; --->mDeviceCallback = callback; //在 mCallOnOpened.run()中用到 --->mDeviceHandler = handler; //在 setRemoteDevice 中用到 --->mCharacteristics = characteristics; --->ICameraDeviceCallbacks callbacks = deviceImpl.getCallbacks(); //获得回调 --->return mCallbacks = new CameraDeviceCallbacks(); --->ICameraService cameraService = CameraManagerGlobal.get().getCameraService(); //获得 CameraService binder 服务。参考《CameraService 守护进程分析》 --->ICameraDeviceUser cameraUser = cameraService.connectDevice(callbacks, cameraId, mContext.getOpPackageName(), uid); //通过binder调用到 CameraService.cpp 的connectDevice函数 --->connectHelper(...) --->makeClient(&client, ...) --->*client = new CameraDeviceClient(...) --->Camera2ClientBase(...) --->mDevice = new Camera3Device(cameraId); --->client->initialize(mCameraProviderManager); // mCameraProviderManager 很关键，在CameraService::enumerateProviders()中设置 --->CameraDeviceClient::initialize() --->initializeImpl(manager); --->Camera2ClientBase::initialize(providerPtr); --->initializeImpl(manager); --->mDevice->initialize(providerPtr); //就是调用 Camera3Device::initialize() --->manager->openSession(mId.string(), this,/*out*/ &session); // manager 的 类型是 class CameraProviderManager, this = Camera3Device 对象 --->CameraProviderManager::openSession(id, callback, session) --->auto deviceInfo = findDeviceInfoLocked(id, {3,0}, {4,0}); --->for (auto& provider : mProviders) //轮循 mProviders, 这个很关键，看下面 mProviders 相关 --->for (auto& deviceInfo : provider->mDevices) //mDevices 在 addDevice 中设置 --->return deviceInfo.get(); --->deviceInfo3->mInterface->open(callback, ...)//mInterface 它实际上是 CameraDevice 对象，参考下面module 与 CameraDevice 相关 --->CameraDevice::open() //V3_2::implementation::CameraDevice --->mModule->open(mCameraId.c_str(), reinterpret_cast(&device)); //调用hal的open函数,得到 device 参考《hal 层分析》 --->mModule->getCameraInfo(mCameraIdInt, &info); //调用hal的get_camera_info函数 --->session = createSession(device, info.static_camera_characteristics, callback); --->new CameraDeviceSession(device, deviceInfo, callback); //注意 CameraDeviceSession::processCaptureRequest() 这个函数。device 由hal层的open()得到 --->mDevice(device) --->mResultBatcher(callback) // mResultBatcher 在FrameProcessorBase中会使用, callback = Camera3Device 对象 --->mSession = session; --->_hidl_cb(status, session->getInterface()); //这个回调函数在deviceInfo3->mInterface->open(...)外面套着，在 CameraProviderManager.cpp 文件中 --->*session = cameraSession; //返回session， 这个session由CameraDeviceSession::getInterface() 得到 --->std::shared_ptr& resQueue = mResultMetadataQueue; --->auto resultQueueRet = session->getCaptureResultMetadataQueue([&resQueue](const auto& descriptor) --->resQueue = std::make_unique3.2 《FrameProcessorBase 分析》
《FrameProcessorBase 分析》 参考 《openCamera 流程》CameraDeviceClient::initializeImpl()--->mFrameProcessor = new FrameProcessorBase(mDevice);--->mFrameProcessor->run(threadName.string()); //进入线程 --->FrameProcessorBase::threadLoop() --->device = mDevice.promote(); //device 就是 Camera3Device 的实例 --->device->waitForNextFrame(kWaitDuration); //等待数据到来 --->while (mResultQueue.empty()) {/* mResultQueue 队列不为空则退出 */} --->processNewFrames(device); //有数据了就处理 --->CaptureResult result; --->device->getNextResult(&result) //device 就是 Camera3Device 的实例 --->CaptureResult &result = *(mResultQueue.begin()); //mResultQueue 参考《数据流分析》 --->frame->mResultExtras = result.mResultExtras; //frame 就是传入的 result，别被名字混淆了 --->frame->mMetadata.acquire(result.mMetadata); //得到数据 --->mResultQueue.erase(mResultQueue.begin()); //取出后擦除 --->camera_metadata_entry_t entry; --->processSingleFrame(result, device) --->processListeners(result, device) //将数据发给 Listener --->ListFilteredListener > > listeners; --->List<RangeListener>::iterator item = mRangeListeners.begin(); //取出迭代器, mRangeListeners 参考 《mRangeListeners 分析》 --->while (item != mRangeListeners.end()) { sp listener = item->listener.promote(); //listener 就是 CameraDeviceClient 实例 listeners.push_back(listener); //压入 } --->ListFilteredListener > >::iterator item = listeners.begin(); //取出迭代器 --->for (; item != listeners.end(); item++) (*item)->onResultAvailable(result); //调用 CameraDeviceClient::onResultAvailable() --->CameraDeviceClient::onResultAvailable() --->sp<hardware::camera2::ICameraDeviceCallbacks> remoteCb = mRemoteCallback; //mRemoteCallback 参考《mRemoteCallback 分析》 --->remoteCb->onResultReceived(result.mMetadata, result.mResultExtras);out/soong/.intermediates/frameworks/av/camera/libcamera_client/android_arm64_armv8-a_kryo300_shared_core/gen/aidl/frameworks/av/camera/aidl/android/hardware/camera2/ICameraDeviceCallbacks.cpp --->BpCameraDeviceCallbacks::onResultReceived(result, resultExtras) --->::android::Parcel _aidl_data; --->_aidl_data.writeInterfaceToken(getInterfaceDescriptor()); --->_aidl_data.writeParcelable(result); --->_aidl_data.writeParcelable(resultExtras); --->remote()->transact(ICameraDeviceCallbacks::ONRESULTRECEIVED, _aidl_data, &_aidl_reply, ::android::IBinder::FLAG_ONEWAY); --->CameraDeviceCallbacks::onResultReceived() //最终会回调回 CameraDeviceCallbacks.java--->mFrameProcessor->registerListener(FRAME_PROCESSOR_LISTENER_MIN_ID, FRAME_PROCESSOR_LISTENER_MAX_ID, /*listener*/this, /*sendPartials*/true); 3.3 《hal 层分析》
《hal 层分析》mModule->open(mCameraId.c_str(), reinterpret_cast(&device)); //mModule是CameraModule对象--->mModule->common.methods->open(&mModule->common, id, device) //这里的mModule是hw_get_module得到的，注意别被名字混淆了 --->qcamera::QCamera2Factory::mModuleMethods::camera_device_open(id, device) //使用的是QCamera2Hal.cpp的hal文件 --->QCamera2Factory::camera_device_open(id, hw_device) --->gQCamera2Factory->cameraDeviceOpen(atoi(id), hw_device); //gQCamera2Factory = new gQCamera2Factory() --->QCamera2Factory::cameraDeviceOpen(id, hw_device) --->QCamera3HardwareInterface *hw = new QCamera3HardwareInterface(mHalDescriptors[camera_id].cameraId, mCallbacks); --->mCameraDevice.common.tag = HARDWARE_DEVICE_TAG; --->mCameraDevice.common.version = CAMERA_DEVICE_API_VERSION_3_4; --->mCameraDevice.common.close = close_camera_device; --->mCameraDevice.ops = &mCameraOps; --->mCameraDevice.priv = this; --->hw->openCamera(hw_device); // QCamera3HardwareInterface 在 QCamera3HWI.cpp --->rc = openCamera(); --->camera_open((uint8_t)mCameraId, &mCameraHandle); --->cam_obj = (mm_camera_obj_t *)malloc(sizeof(mm_camera_obj_t)); --->cam_obj->my_hdl = mm_camera_util_generate_handler(cam_idx); --->cam_obj->vtbl.camera_handle = cam_obj->my_hdl; /* set handler */ --->cam_obj->vtbl.ops = &mm_camera_ops; // mm_camera_ops 结构体在当前文件下定义 --->mm_camera_open(cam_obj); --->sscanf(dev_name, "/dev/video%d", &cam_idx); --->my_obj->ctrl_fd = open(dev_name, O_RDWR | O_NONBLOCK); //my_obj就是传入的cam_obj --->mm_camera_get_session_id(my_obj, &my_obj->sessionid); --->struct v4l2_control control; --->control.id = MSM_CAMERA_PRIV_G_SESSION_ID; --->control.value = value; --->ioctl(my_obj->ctrl_fd, VIDIOC_G_CTRL, &control); --->*sessionid = control.value; //返回sessionid --->mm_camera_evt_sub(my_obj, TRUE); --->rc = ioctl(my_obj->ctrl_fd, VIDIOC_SUBSCRIBE_EVENT, &sub); --->mm_camera_poll_thread_add_poll_fd(&my_obj->evt_poll_thread, 0, my_obj->my_hdl, my_obj->ctrl_fd, mm_camera_event_notify,(void*)my_obj, mm_camera_sync_call); ---> g_cam_ctrl.cam_obj[cam_idx] = cam_obj; --->*camera_vtbl = &cam_obj->vtbl; //返回 mCameraHandle --->mCameraHandle->ops->register_event_notify(mCameraHandle->camera_handle, camEvtHandle, (void *)this); //注册通知回调 --->mm_camera_intf_register_event_notify(mCameraHandle->camera_handle, camEvtHandle, (void *)this) //mm_camera_interface.c --->*hw_device = &mCameraDevice.common; //返回hw_device 3.4 《数据流分析》
《数据流分析》Camera3Device::RequestThread::threadLoop()--->waitForNextRequestBatch(); //等待请求, 之后再分析这里，理清请求是如何生成的--->submitRequestSuccess = sendRequestsOneByOne(); //发送一个请求 --->mInterface->processCaptureRequest(&nextRequest.halRequest); //mInterface = new HalInterface(session, queue) Camera3Device.cpp --->std::vector(request->settings), settingsSize) --->mHidlSession->processCaptureRequest(captureRequests, cachesToRemove, [&status, &numRequestProcessed] (auto s, uint32_t n) //mHidlSession = new CameraDeviceSession() --->processOneCaptureRequest(requests[i]) --->mDevice->ops->process_capture_request(mDevice, &halRequest); //mDevice 由hal层的open()得到， 就是struct camera3_device 结构体 --->QCamera3HardwareInterface::mCameraOps::process_capture_request(device， request) //就是调用这个函数 QCamera3HWI.cpp --->QCamera3HardwareInterface *hw = reinterpret_cast<QCamera3HardwareInterface *>(device->priv); //device->priv 在 new QCamera3HardwareInterface() 时构造函数中候赋值 --->hw->orchestrateRequest(request); --->_orchestrationDb.allocStoreInternalFrameNumber(request->frame_number, internalFrameNumber); --->request->frame_number = internalFrameNumber; --->processCaptureRequest(request, internallyRequestedStreams); --->CameraMetadata meta; --->meta = request->settings; --->mCameraHandle->ops->set_parms(mCameraHandle->camera_handle, mParameters); //mCameraHandle由camera_open((uint8_t)mCameraId, &mCameraHandle)得到。mCameraHandle->ops是 mm_camera_ops 结构体 --->mm_camera_set_parms(my_obj, parms); --->mm_camera_util_s_ctrl(my_obj, 0, my_obj->ctrl_fd, CAM_PRIV_PARM, &value); --->ioctl(fd, VIDIOC_S_CTRL, &control); //最终调用到ioctl --->mMetadataChannel->start(); --->mStreams[i]->start(); //开启这些Stream的线程 --->mDataQ.init(); // mDataQ 是之后线程需要处理的数据，由其他线程put进来 --->mProcTh.launch(dataProcRoutine, this); //开启线程 --->QCamera3Stream::dataProcRoutine(void *data) ---> QCamera3Stream *pme = (QCamera3Stream *)data; --->QCameraCmdThread *cmdThread = &pme->mProcTh; --->cam_sem_wait(&cmdThread->cmd_sem); //等待唤醒 参考第二部分 --->camera_cmd_type_t cmd = cmdThread->getCmd(); //根据cmd选择执行代码 我们分析 CAMERA_CMD_TYPE_DO_NEXT_JOB --->mm_camera_super_buf_t *frame = (mm_camera_super_buf_t *)pme->mDataQ.dequeue(); --->pme->mDataCB(frame, pme, pme->mUserData); //调用回调 就是QCamera3Channel::streamCbRoutine() --->QCamera3Channel *channel = (QCamera3Channel *)userdata; --->channel->streamCbRoutine(super_frame, stream); --->QCamera3ProcessingChannel::streamCbRoutine(mm_camera_super_buf_t *super_frame, QCamera3Stream *stream) --->camera3_stream_buffer_t result; --->frameIndex = (uint8_t)super_frame->bufs[0]->buf_idx; --->resultBuffer = (buffer_handle_t *)mMemory.getBufferHandle(frameIndex); --->resultFrameNumber = mMemory.getFrameNumber(frameIndex); --->QCamera3HardwareInterface* hal_obj = (QCamera3HardwareInterface*)mUserData; --->result.stream = mCamera3Stream; --->result.buffer = resultBuffer; --->mChannelCB(NULL, &result, (uint32_t)resultFrameNumber, false, mUserData); //回调函数 QCamera3HardwareInterface::captureResultCb() --->captureResultCb(mm_camera_super_buf_t *metadata_buf, camera3_stream_buffer_t *buffer, uint32_t frame_number, bool isInputBuffer) --->handleBufferWithLock(buffer, frame_number); --->camera3_capture_result_t result; //构造camera3_capture_result_t --->result.result = NULL; --->result.frame_number = frame_number; --->result.num_output_buffers = 1; --->result.output_buffers = buffer; --->orchestrateResult(&result); --->mCallbackOps->process_capture_result(mCallbackOps, result); //就是调用 Camera3Device::sProcessCaptureResult() --->Camera3Device *d = const_cast<Camera3Device*>(static_castCamera3Device *>(cb)); --->d->processCaptureResult(result); --->uint32_t frameNumber = result->frame_number; --->CameraMetadata metadata; --->metadata = result->result; --->sendCaptureResult(metadata, request.resultExtras, collectedPartialResult, frameNumber, hasInputBufferInRequest); --->CaptureResult captureResult; //构造 CaptureResult --->captureResult.mResultExtras = resultExtras; --->captureResult.mMetadata = pendingMetadata; --->captureResult.mMetadata.sort(); --->insertResultLocked(&captureResult, frameNumber); //将CaptureResult插入mResultQueue队列 --->List<CaptureResult>::iterator queuedResult = mResultQueue.insert(mResultQueue.end(), CaptureResult(*result)); --->mResultSignal.signal(); //发送信号唤醒 FrameProcessorBase 线程第二部分：QCamera3Stream::init()--->mHandle = mCamOps->add_stream(mCamHandle, mChannelHandle);--->stream_config.stream_info = mStreamInfo;--->stream_config.mem_vtbl = mMemVtbl;--->stream_config.padding_info = mPaddingInfo;--->stream_config.userdata = this;--->stream_config.stream_cb = dataNotifyCB; //回调函数:QCamera3Stream::dataNotifyCB(), 把这个回调函数注册到底层，当有数据是使用这个函数通知--->stream_config.stream_cb_sync = NULL;--->rc = mCamOps->config_stream(mCamHandle, mChannelHandle, mHandle, &stream_config);--->mDataCB = stream_cb; //stream_cb 就是QCamera3Channel::streamCbRoutine()QCamera3Stream::dataNotifyCB(mm_camera_super_buf_t *recvd_frame, void *userdata)--->QCamera3Stream* stream = (QCamera3Stream *)userdata;--->mm_camera_super_buf_t *frame = (mm_camera_super_buf_t *)malloc(sizeof(mm_camera_super_buf_t));--->*frame = *recvd_frame;--->stream->processDataNotify(frame); --->mDataQ.enqueue((void *)frame) //压入队列 --->mProcTh.sendCmd(CAMERA_CMD_TYPE_DO_NEXT_JOB, FALSE, FALSE); //向QCameraCmdThread线程发送命令，表明有数据需要处理3.5 《CameraService初始化 分析》
《CameraService初始化 分析》, 参考《CameraService 守护进程分析》CameraService 守护进程会实例化 CameraService 并，引用这个实例frameworks/av/services/camera/libcameraservice/CameraService.cppCameraService::CameraService()---> 构造函数里面什么也没做，但是第一次引用 CameraService 实例的时候会调用 CameraService::onFirstRef()CameraService::onFirstRef()--->BnCameraService::onFirstRef();--->enumerateProviders(); --->mCameraProviderManager = new CameraProviderManager(); --->mCameraProviderManager->initialize(this); --->mListener = listener; // listener = CameraService 对象 --->mServiceProxy = proxy; // ServiceInteractionProxy *proxy = &sHardwareServiceInteractionProxy --->addProviderLocked(kLegacyProviderName, false); // kLegacyProviderName = legacy/0 --->sp<provider::V2_4::ICameraProvider> interface; --->interface = mServiceProxy->getService(newProvider); // 就是调用 HardwareServiceInteractionProxy::getService() --->HardwareServiceInteractionProxy::getService() --->return hardware::camera::provider::V2_4::ICameraProvider::getService(serviceName);//《ICameraProvider::getService(getStub = false) 分析》 --->providerInfo = new ProviderInfo(newProvider, interface, this); //interface 是通过ICameraProvider::getService()得到的 --->mInterface(interface) --->providerInfo->initialize(); --->addDevice(device,hardware::camera::common::V1_0::CameraDeviceStatus::PRESENT, &id); --->std::unique_ptrDeviceInfoT::InterfaceT >(name); --->CameraProviderManager::ProviderInfo::getDeviceInterface() --->mInterface->getCameraDeviceInterface_V3_x(&status, &cameraInterface) //mInterface 就是 ICameraProvider。 //参考 《module 与 CameraDevice 相关》 --->return cameraInterface; //这个就是 CameraDevice 实例化对象 --->return std::unique_ptr3.6 《module 与 CameraDevice 相关》
《module 与 CameraDevice 相关》 参考 《CameraService初始化 分析》一起看hardware/interfaces/camera/provider/2.4/default/CameraProvider.cppCameraProvider::getCameraDeviceInterface_V3_x(getCameraDeviceInterface_V3_x_cb _hidl_cb)--->deviceImpl = new android::hardware::camera::device::V3_3::implementation::CameraDevice(mModule, ...); //这里将mModule与CameraDevice联系起来了 --->V3_2::implementation::CameraDevice(module, cameraId, cameraDeviceNames) // module 是 CameraModule 实例化对象 --->mModule(module)--->device = deviceImpl;--->_hidl_cb (Status::OK, device); //回调函数所以:CameraDevice::open()--->mModule->open(mCameraId.c_str(), reinterpret_cast(&device)); //调用hal的open函数 3.7 《mRangeListeners 分析》
《mRangeListeners 分析》CameraDeviceClient::initializeImpl()--->mFrameProcessor->registerListener(FRAME_PROCESSOR_LISTENER_MIN_ID, FRAME_PROCESSOR_LISTENER_MAX_ID, /*listener*/this, /*sendPartials*/true); --->RangeListener rListener = { minId, maxId, listener, sendPartials }; --->mRangeListeners.push_back(rListener);3.8 《mRemoteCallback 分析》
《mRemoteCallback 分析》CameraService::connectDevice(const sp& cameraCb, ...)--->connectHelper(cameraCb,...; --->makeClient(this, cameraCb, ...) --->sp tmp = static_cast(cameraCb.get()); //构造回调 --->*client = new CameraDeviceClient(cameraService, tmp, packageName, cameraId, facing, clientPid, clientUid, servicePid); --->CameraDeviceClientBase::CameraDeviceClientBase(remoteCallback, ...) --->mRemoteCallback(remoteCallback) 4 总结
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