Camera Framework 架構(gòu)了解下

和你一起終身學習，這里是程序員Android

通過閱讀本文您將收獲以下知識點:

一、 Camera Framework 列文件目錄
二、 JNI 相關(guān)
三、 AIDL 相關(guān)
四、 IInterface 類型文件
五、Parcelable 類型文件
六、ICameraService 相關(guān)
七、 ICameraServiceProxy.aidl 文件
八、 ICamera 相關(guān)
九、 ICameraDevice 相關(guān)
十、 Services 目錄下的文件介紹
十一、API1/API2
十二、QTICamera2Client
十三、Device1/Device3

一、 Camera Framework 列文件目錄

1.API1:(frameworks/base/core/java/android/hardware/Camera.java)
2.API2:(frameworks/base/core/java/android/hardware/camera2/)
3.JNI:?(frameworks/base/core/jni/)
4.AIDL:( frameworks/av/camera/aidl/)
5.Native:?(frameworks/av/camera/)
6.Service:?(frameworks/av/services/camera/libcameraservice/)
7.Qcom Hal:?(vendor/qcom/propietary/camx/)
8.Qcom Kernel：(kernel/msm-4.19/techpack/camera/)

二、 JNI 相關(guān)

主目錄為?frameworks/base/core/jni

//frameworks/base/core/jni
./android_hardware_camera2_legacy_LegacyCameraDevice.cpp
./android_hardware_Camera.cpp
./android/graphics/Camera.cpp
./include/android_runtime/android_hardware_camera2_CameraMetadata.h
./android_hardware_camera2_DngCreator.cpp
./android_hardware_camera2_CameraMetadata.cpp
./android_hardware_camera2_legacy_PerfMeasurement.cpp

API 1 中，使用 jni 通過 Binder 機制和 CameraService 通信。

API 2 中，直接在 CameraManager.java 中通過 Binder 機制和 CameraService 通信。

三、 AIDL 相關(guān)

Framework Camera AIDL 是 Camera 中客戶端和服務(wù)端跨進程通信時使用的 AIDL 文件，代碼都在frameworks/av/camera/目錄下，其中 aidl 文件一共有 16 個

xmt@server005:~/frameworks/av/camera/aidl/android/hardware$ tree
.
├—— camera2
│?? ├—— CaptureRequest.aidl
│?? ├—— ICameraDeviceCallbacks.aidl
│?? ├—— ICameraDeviceUser.aidl
│?? ├—— impl
│?? │??├—— CameraMetadataNative.aidl
│?? │??└—— CaptureResultExtras.aidl
│?? ├—— params
│?? │??├—— OutputConfiguration.aidl
│?? │??├—— VendorTagDescriptor.aidl
│?? │??└—— VendorTagDescriptorCache.aidl
│?? └—— utils
│?????? └—— SubmitInfo.aidl
├—— CameraInfo.aidl
├—— CameraStatus.aidl
├—— ICamera.aidl
├—— ICameraClient.aidl
├—— ICameraService.aidl
├—— ICameraServiceListener.aidl
└—— ICameraServiceProxy.aidl

4directories,?16?files

frameworks/av/camera/aidl/目錄下的 aidl 文件有兩種類型：

• 作為 Binder 中的 IInterface 跨進程通信中能提供的方法

• 作為 Binder 中的 parcelable 跨進程通信數(shù)據(jù)傳輸?shù)臄?shù)據(jù)結(jié)構(gòu)

很容易從名字上區(qū)分這兩種類型的文件，IInterface 類型的文件都是以 I 開頭的，比如：ICameraService.aidl, ICameraDeviceUser.aidl等。不管是哪種類型的 aidl 文件，它們都會生成對應(yīng)的 .java, .h, .cpp 文件，分別供 Java 層和 CPP 層調(diào)用。

四、 IInterface 類型文件

IInterface 類型文件一共有 7 個，它們的 .java, .h, .cpp 文件，絕大部分都是自動生成的。

Java 文件是在?frameworks/base/Android.mk?中定義規(guī)則，在編譯時自動生成：

//frameworks/base/Android.mk
LOCAL_SRC_FILES +=?
??? ...
???../av/camera/aidl/android/hardware/ICameraService.aidl?
???../av/camera/aidl/android/hardware/ICameraServiceListener.aidl?
???../av/camera/aidl/android/hardware/ICameraServiceProxy.aidl?
???../av/camera/aidl/android/hardware/ICamera.aidl?
??? ../av/camera/aidl/android/hardware/ICameraClient.aidl
???../av/camera/aidl/android/hardware/camera2/ICameraDeviceUser.aidl?
???../av/camera/aidl/android/hardware/camera2/ICameraDeviceCallbacks.aidl?
??? ...
?...

在?out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/dotdot/?目錄下生成對應(yīng)的?Java?文件：

//out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/dotdot/
av/camera/aidl/android/hardware/ICameraService.java
av/camera/aidl/android/hardware/ICameraServiceListener.java
av/camera/aidl/android/hardware/ICameraServiceProxy.java
av/camera/aidl/android/hardware/ICamera.java
av/camera/aidl/android/hardware/ICameraClient.java
av/camera/aidl/android/hardware/camera2/ICameraDeviceUser.java
av/camera/aidl/android/hardware/camera2/ICameraDeviceCallbacks.java

.h, .cpp?文件中，ICamera.aidl, ICameraClient.aidl?兩個文件是直接以代碼形式手動實現(xiàn)的：

// 1. ICameraClient.aidl
frameworks/av/camera/aidl/android/hardware/ICameraClient.aidl
frameworks/av/camera/include/camera/android/hardware/ICameraClient.h
frameworks/av/camera/ICameraClient.cpp

// 2.ICamera.aidl
frameworks/av/camera/aidl/android/hardware/ICamera.aidl
frameworks/av/camera/include/camera/android/hardware/ICamera.h
frameworks/av/camera/ICamera.cpp

其他 5 個?aidl?文件是在?frameworks/av/camera/Android.bp?中定義規(guī)則，編譯時自動生成對應(yīng)的?.h, .cpp?文件：

//frameworks/av/camera/Android.bp
cc_library_shared {
??? name:?"libcamera_client",

??? aidl: {
??????? export_aidl_headers:?true,
??????? local_include_dirs: ["aidl"],
??????? include_dirs: [
????????????"frameworks/native/aidl/gui",
??????? ],
??? },

??? srcs: [
????????// AIDL files for camerainterfaces
????????// The headers for theseinterfaces will be?
????????// available to anymodules that
????????// include libcamera_client,at the path "aidl/package/path/BnFoo.h"
????????"aidl/android/hardware/ICameraService.aidl",
????????"aidl/android/hardware/ICameraServiceListener.aidl",
????????"aidl/android/hardware/ICameraServiceProxy.aidl",
????????"aidl/android/hardware/camera2/ICameraDeviceCallbacks.aidl",
????????"aidl/android/hardware/camera2/ICameraDeviceUser.aidl",


????????// Source for camerainterface parcelables,?
????????// and manually-writteninterfaces
????????"Camera.cpp",
????????"CameraMetadata.cpp",
????????"CameraParameters.cpp",
??????? ...
}

在?out/soong/.intermediates/frameworks/av/camera/libcamera_client/?目錄下生成對應(yīng)的?.h, .cpp?文件，通常在該目錄下會同時生成 32 和 64 位兩套代碼，但實際兩份代碼是一樣的，這里選取 64 位的：

• 64 位：android_arm64_armv8-a_shared_core

• 32 位：android_arm_armv7-a-neon_cortex-a53_shared_core

//?目錄out/soong/.intermediates/frameworks/av/camera/libcamera_client// 64?位?android_arm64_armv8-a_shared_core/gen/aidl/
android/hardware/ICameraService.h
android/hardware/BnCameraService.h
frameworks/av/camera/aidl/android/hardware/ICameraService.cpp

android/hardware/ICameraServiceListener.h
android/hardware/BnCameraServiceListener.h
frameworks/av/camera/aidl/android/hardware/ICameraServiceListener.cpp

android/hardware/ICameraServiceProxy.h
android/hardware/BnCameraServiceProxy.h
frameworks/av/camera/aidl/android/hardware/ICameraServiceProxy.cpp

android/hardware/camera2/ICameraDeviceUser.h
android/hardware/camera2/BnCameraDeviceUser.h
frameworks/av/camera/aidl/android/hardware/camera2/ICameraDeviceUser.cpp

android/hardware/camera2/ICameraDeviceCallbacks.h
android/hardware/camera2/BnCameraDeviceCallbacks.h
frameworks/av/camera/aidl/android/hardware/camera2/ICameraDeviceCallbacks.cpp

五、 parcelable 類型文件

parcelable?類型文件一共有 9 個，它們都是手動編寫的代碼。

Java?文件目錄為?frameworks/base/core/java/android/hardware/?：

//frameworks/base/core/java/android/hardware/
camera2/CaptureRequest.java
camera2/impl/CameraMetadataNative.java
camera2/impl/CaptureResultExtras.java
camera2/params/OutputConfiguration.java
camera2/params/VendorTagDescriptor.java
camera2/params/VendorTagDescriptorCache.java
camera2/utils/SubmitInfo.java
CameraInfo.java
CameraStatus.java

.h, .cpp?文件并不一定是和?aidl?文件名稱一一對應(yīng)的，而是在?aidl?文件中定義的，比如?CameraStatus.aidl?定義如下：

packageandroid.hardware;

/**?@hide?*/
parcelable CameraStatus cpp_header?"camera/CameraBase.h";

parcelable?類型的?aidl?文件對應(yīng)的?.h, .cpp?文件目錄為?frameworks/av/camera?，對應(yīng)關(guān)系整理如下：

// .h, .cpp?文件目錄?frameworks/av/camera//CaptureRequest.aidlinclude/camera/camera2/CaptureRequest.h
camera2/CaptureRequest.cpp

//CameraMetadataNative.aidlinclude/camera/CameraMetadata.h
CameraMetadata.cpp

//CaptureResultExtras.aidlinclude/camera/CaptureResult.h
CaptureResult.cpp

//OutputConfiguration.aidlinclude/camera/camera2/OutputConfiguration.h
camera2/OutputConfiguration.cpp

//VendorTagDescriptor.aidl?和VendorTagDescriptorCache.aidlinclude/camera/VendorTagDescriptor.h
VendorTagDescriptor.cpp

//SubmitInfo.aidlinclude/camera/camera2/SubmitInfo.h
camera2/SubmitInfo.cpp

//CameraInfo.aidl?和?CameraStatus.aidlinclude/camera/CameraBase.h
CameraBase.cpp

六、ICameraService 相關(guān)

分為客戶端向服務(wù)端的請求?ICameraService.aidl?和客戶端監(jiān)聽服務(wù)端的變化?ICameraServiceListener.aidl?。這兩個?AIDL?是在?CameraService.cpp?中實現(xiàn)對應(yīng)功能的。

interface?
{
??? ...
????constintCAMERA_TYPE_BACKWARD_COMPATIBLE =?0;
????constint?CAMERA_TYPE_ALL=?1;

????//?返回指定類型的相機設(shè)備數(shù)量
????intgetNumberOfCameras(int?type);
????//?根據(jù)?id?返回當前相機設(shè)備信息
??? CameraInfo?getCameraInfo(intcameraId);

??? ...
????constintCAMERA_HAL_API_VERSION_UNSPECIFIED = -1;
????// api1 + hal1
??? ICamera?connect(ICameraClientclient,
????????????int?cameraId,
??????????? String opPackageName,
????????????intclientUid,?intclientPid);

????// api2 + hal3
??? ICameraDeviceUser?connectDevice(ICameraDeviceCallbackscallbacks,
??????????? String cameraId,
??????????? String opPackageName,
????????????intclientUid);

????// api1 +?指定?hal?版本（通常為?hal1）
??? ICamera?connectLegacy(ICameraClientclient,
????????????int?cameraId,
????????????inthalVersion,
??????????? String opPackageName,
????????????intclientUid);

????//?添加和移除?ICameraServiceListener?監(jiān)聽
??? CameraStatus[] addListener(ICameraServiceListenerlistener);
????voidremoveListener(ICameraServiceListenerlistener);

????//?根據(jù)?id?返回相機支持的屬性
??? CameraMetadataNative?getCameraCharacteristics(StringcameraId);

????//?獲取?vendor tag?
??? VendorTagDescriptor?getCameraVendorTagDescriptor();
??? VendorTagDescriptorCache?getCameraVendorTagCache();

????// camera api 1?獲取參數(shù)信息
??? String?getLegacyParameters(intcameraId);

????constintAPI_VERSION_1 =?1;
????constintAPI_VERSION_2 =?2;
????//?指定?id?支持的?API?版本
????booleansupportsCameraApi(StringcameraId,?intapiVersion);
????//?指定?id?設(shè)置手電筒模式
????voidsetTorchMode(StringcameraId,?boolean?enabled,?
??????? IBinder clientBinder);

????//?服務(wù)端向系統(tǒng)打印系統(tǒng)消息
????constintEVENT_NONE =?0;
????constintEVENT_USER_SWITCHED =?1;
??? oneway?voidnotifySystemEvent(int?eventId,in?int[] args);
}

// 2.ICameraServiceListener.aidlinterfaceICameraServiceListener
{
????constintSTATUS_NOT_PRESENT????? =?0;
????constintSTATUS_PRESENT????????? =?1;
????constintSTATUS_ENUMERATING????? =?2;
????constintSTATUS_NOT_AVAILABLE??? = -2;
????constintSTATUS_UNKNOWN????????? = -1;
????//?相機設(shè)備狀態(tài)變化事件
??? oneway?voidonStatusChanged(int?status,String cameraId);

????constintTORCH_STATUS_NOT_AVAILABLE =?0;
????constintTORCH_STATUS_AVAILABLE_OFF =?1;
????constintTORCH_STATUS_AVAILABLE_ON? =?2;
????constintTORCH_STATUS_UNKNOWN = -1;
????//?手電筒狀態(tài)變化事件
??? oneway?voidonTorchStatusChanged(int?status,String cameraId);
}

七、 ICameraServiceProxy.aidl 文件

CameraServiceProxy?服務(wù)是在?Java?層注冊的

interfaceICameraServiceProxy
{
????// CameraService?向代理服務(wù)發(fā)送消息，通知用戶更新
????onewayvoidpingForUserUpdate();

????constintCAMERA_STATE_OPEN?=?0;
????constintCAMERA_STATE_ACTIVE?=?1;
????constintCAMERA_STATE_IDLE?=?2;
????constintCAMERA_STATE_CLOSED?=?3;
????constintCAMERA_FACING_BACK?=?0;
????constintCAMERA_FACING_FRONT?=?1;
????constintCAMERA_FACING_EXTERNAL?=?2;

????// CameraService?向代理服務(wù)發(fā)送消息，通知相機設(shè)備狀態(tài)更新
????onewayvoidnotifyCameraState(String cameraId,?int?facing,?
????????????intnewCameraState, String clientName);
}

八、 ICamera 相關(guān)

Camera API1 才會使用到，分為 ICamera.aidl, ICameraClient.aidl
它們的代碼是手動實現(xiàn)的，參考：CameraClient.h/cpp, Camera.h/cpp

九、ICameraDevice 相關(guān)

Camera API2 才會使用到，分為客戶端向服務(wù)端的請求 ICameraDeviceUser.aidl 和服務(wù)端發(fā)給客戶端的回調(diào) ICameraDeviceCallbacks.aidl 。
表示相機設(shè)備具備的能力，能夠提供的函數(shù)；這兩個 AIDL 是在 CameraDeviceClient 中實現(xiàn)對應(yīng)功能的

// 1.ICameraDeviceUser.aidl?interfaceICameraDeviceUser
{
?? ?voiddisconnect();

????constintNO_IN_FLIGHT_REPEATING_FRAMES = -1;
????//?向設(shè)備提交捕獲請求
??? SubmitInfo?submitRequest(inCaptureRequest request,?boolean?streaming);
??? SubmitInfo?submitRequestList(inCaptureRequest[] requestList,?
????????boolean?streaming);
????//?取消置頂?id?的重復請求，并返回上次請求的幀?id
????longcancelRequest(intrequestId);

????constintNORMAL_MODE =?0;
????constintCONSTRAINED_HIGH_SPEED_MODE =?1;
????constintVENDOR_MODE_START =?0x8000;

????//?在流處理前執(zhí)行配置請求
????voidbeginConfigure();
????//?根據(jù)指定輸出配置，創(chuàng)建流
????intcreateStream(inOutputConfiguration outputConfiguration);
????voidendConfigure(intoperatingMode);
????voiddeleteStream(intstreamId);

????//?創(chuàng)建輸入流，返回流?id
????intcreateInputStream(int?width,?int?height,?int?format);
????//?返回輸入流的?Surface
??? Surface?getInputSurface();

????// Keep in sync withpublic API in
????//frameworks/base/core/java/android/hardware/camera2/CameraDevice.java
????constintTEMPLATE_PREVIEW =?1;
????constintTEMPLATE_STILL_CAPTURE =?2;
????constintTEMPLATE_RECORD =?3;
????constintTEMPLATE_VIDEO_SNAPSHOT =?4;
????constintTEMPLATE_ZERO_SHUTTER_LAG =?5;
????constintTEMPLATE_MANUAL =?6;
????//?根據(jù)模板創(chuàng)建默認請求，返回相機參數(shù)信息
??? CameraMetadataNative?createDefaultRequest(inttemplateId);
????//?獲取相機參數(shù)信息
??? CameraMetadataNative?getCameraInfo();
????voidwaitUntilIdle();
????longflush();
????voidprepare(intstreamId);
????voidtearDown(intstreamId);
????voidprepare2(int?maxCount,intstreamId);
????voidfinalizeOutputConfigurations(int?streamId,
??????? in OutputConfigurationoutputConfiguration);
}

// 2.ICameraDeviceCallbacks.aidlinterfaceICameraDeviceCallbacks
{
??? ...
??? oneway?voidonDeviceError(interrorCode,?
??????? in CaptureResultExtrasresultExtras);
??? oneway?voidonDeviceIdle();
??? oneway?voidonCaptureStarted(inCaptureResultExtras resultExtras,?
????????longtimestamp);
??? oneway?voidonResultReceived(inCameraMetadataNative result,
???????????????????????????????? inCaptureResultExtras resultExtras);
??? oneway?voidonPrepared(intstreamId);
????//?重復請求引起的錯誤回調(diào)
??? oneway?voidonRepeatingRequestError(in?longlastFrameNumber,
???????????????????????????????????????in?intrepeatingRequestId);
??? oneway?voidonRequestQueueEmpty();
}

十、Services 目錄下的文件介紹

frameworks/av/services/camera/libcameraservice?AOSP 中這個目錄下是 87 個文件，而 Qcom 的基線中增加了 27 個文件，分別為 api1/qticlient2 目錄下的 25 個文件，以及 QTICamera2Client.cpp, QTICamera2Client.h 兩個文件。

.
├——?Android.mk
├——?api1
│?? ├——?client2
│?? └——?qticlient2
├——?api2
├——?CameraFlashlight.cpp
├——?CameraFlashlight.h
├——?CameraService.cpp
├——?CameraService.h
├——?common
├——?device1
├——?device3
├——?gui
├——?MODULE_LICENSE_APACHE2
├——?NOTICE
├——?tests
└——?utils

從目錄結(jié)構(gòu)上可以看出，API1/2?和?HAL1/3?就是在這一層體現(xiàn)的。

十一、 API1/API2

APP Java 客戶端調(diào)用服務(wù)端方法時，Camera API1/2 接口對應(yīng)功能都是在 CameraService 中實現(xiàn)的，而這里的 API1/2 目錄對應(yīng)的就是對上層不同版本接口的處理

api1
├——?Camera2Client.cpp
├——?Camera2Client.h
├——?CameraClient.cpp
├——?CameraClient.h
├——?client2
│?? ├——?CallbackProcessor.cpp
│?? ├——?CallbackProcessor.h
│?? ├——?Camera2Heap.h
│?? ├——?CaptureSequencer.cpp
│?? ├——?CaptureSequencer.h
│ ??├——?FrameProcessor.cpp
│?? ├——?FrameProcessor.h
│?? ├——?JpegCompressor.cpp
│?? ├——?JpegCompressor.h
│?? ├——?JpegProcessor.cpp
│?? ├——?JpegProcessor.h
│?? ├——?Parameters.cpp
│?? ├——?Parameters.h
│?? ├——?StreamingProcessor.cpp
│?? ├——?StreamingProcessor.h
│?? ├——?ZslProcessor.cpp
│?? └——?ZslProcessor.h
├——?QTICamera2Client.cpp
├——?QTICamera2Client.h
└——?qticlient2
??? ├——?CallbackProcessor.cpp
??? ├——?CallbackProcessor.h
??? ├——?Camera2Heap.h
??? ├——?CaptureSequencer.cpp
??? ├——?CaptureSequencer.h
??? ├——?FrameProcessor.cpp
??? ├——?FrameProcessor.h
??? ├——?JpegCompressor.cpp
??? ├——?JpegCompressor.h
??? ├——?JpegProcessor.cpp
??? ├——?JpegProcessor.h
??? ├——?Parameters.cpp
??? ├——?Parameters.h
??? ├——?QTICaptureSequencer.cpp
??? ├——?QTICaptureSequencer.h
??? ├——?QTIFrameProcessor.cpp
??? ├——?QTIFrameProcessor.h
??? ├——?QTIParameters.cpp
??? ├——?QTIParameters.h
??? ├——?RawProcessor.cpp
??? ├——?RawProcessor.h
??? ├——?StreamingProcessor.cpp
??? ├——?StreamingProcessor.h
??? ├——?ZslProcessor.cpp
??? └——?ZslProcessor.hapi2
├——?CameraDeviceClient.cpp
└——?CameraDeviceClient.h

BasicClient 有三個重要的子類：

• CameraClient
  如果平臺僅支持 HAL 1，即 CAMERA_DEVICE_API_VERSION_1_0 ；使用 API 1/2 + HAL 1 都會對應(yīng)該客戶端。

• Camera2Client
  如果平臺支持 HAL 3 ，即 CAMERA_DEVICE_API_VERSION_3_0 及以上版本；使用 API 1 + HAL 3 對應(yīng)的客戶端。Camera2Client 會將 API1 中的接口轉(zhuǎn)換為 API2 中對應(yīng)的功能。

• CameraDeviceClient
  如果平臺支持 HAL 3 ，使用 API 2 + HAL 3 對應(yīng)的客戶端。
  平臺僅支持 HAL 1 時，API 2 在 openCamera 時，通過 CameraDeviceUserShim 將 API 2 轉(zhuǎn)換為 API 1 ，即 HAL 1 + API 1 向下發(fā)起請求。
  LegacyCameraDevice 會將 CAMERA API2 轉(zhuǎn)換為 CAMERA API1 ，而 CameraDeviceUserShim 封裝了 LegacyCameraDevice 。

十二、 QTICamera2Client

Qcom 的基線中增加了 27 個文件，分別為 api1/qticlient2 目錄下的 25 個文件，以及 QTICamera2Client.cpp, QTICamera2Client.h 兩個文件。
而 QTICamera2Client 是高通針對 API1 做的優(yōu)化？在什么情況下會轉(zhuǎn)換為 QTICamera2Client 呢？看如下源碼

classCamera2Client?:
????????publicCamera2ClientBase
{

friendclassQTICamera2Client;
#endif
...

??? spmRawProcessor;
#endif
...

??? spmQTICamera2Client;
#endif
...
}

// 2.Camera2Client.cpptemplate<typenameTProviderPtr>
status_tCamera2Client::initializeImpl(TProviderPtr providerPtr)
{
...

??? mQTICamera2Client =?newQTICamera2Client(this);
#endif
...

??? mRawProcessor =?newRawProcessor(this,mCaptureSequencer);
??? threadName = String8::format("C2-%d-RawProc",mCameraId);
??? mRawProcessor->run(threadName.string());
#endif
...
}

QTICamera2Client 是高通對 API 1 中 Camera2Client 做的一層封裝，添加了部分功能，主要是向上提供 raw 數(shù)據(jù)。

// 1. QTICamera2Client.hclassQTICamera2Client:?publicvirtual?RefBase{
private:
??? wpmParentClient;
????status_tstopPreviewExtn();

public:
???QTICamera2Client(sp client);
??? ~QTICamera2Client();
??? ...
}

// 2.QTICamera2Client.cpp
QTICamera2Client::QTICamera2Client(sp client):
??????? mParentClient(client) {
}

十三、 device1/device3

device1/device3 可以理解為 Framework 層對應(yīng) HAL 層的 HAL 1/3 。

device1
├——?CameraHardwareInterface.cpp
└——?CameraHardwareInterface.hdevice3
├——?Camera3BufferManager.cpp
├——?Camera3BufferManager.h
├——?Camera3Device.cpp
├——?Camera3Device.h
├——?Camera3DummyStream.cpp
├——?Camera3DummyStream.h
├——?Camera3InputStream.cpp
├——?Camera3InputStream.h
├——?Camera3IOStreamBase.cpp
├——?Camera3IOStreamBase.h
├——?Camera3OutputStream.cpp
├——?Camera3OutputStream.h
├——?Camera3OutputStreamInterface.h
├——?Camera3SharedOutputStream.cpp
├——?Camera3SharedOutputStream.h
├——?Camera3StreamBufferFreedListener.h
├——?Camera3StreamBufferListener.h
├——?Camera3Stream.cpp
├——?Camera3Stream.h
├——?Camera3StreamInterface.h
├——?Camera3StreamSplitter.cpp
├——?Camera3StreamSplitter.h
├——?StatusTracker.cpp
└——?StatusTracker.h

• API1/device1/HAL1?的連接過程

// API1: CameraClient.h
sp????mHardware;
//device1: CameraHardwareInterface.h
sp mHidlDevice;
//?這里的?ICameraDevice?即為?HAL1API1 的客戶端 CameraClient 對應(yīng)的 device1: CameraHardwareInterface，而它直接包含了 HAL1 中 ICameraDevice

• API1/3/device3/HAL3?的連接過程

// API1: Camera2Client.hclassCamera2Client?:
????publicCamera2ClientBase{...}

// API2:CameraDeviceClient.hclassCameraDeviceClient?:
????publicCamera2ClientBase,
????publiccamera2::FrameProcessorBase::FilteredListener{...}

//Camera2ClientBase.h
sp? mDevice;

//Camera2ClientBase.cpptemplate?<typenameTClientBase>
Camera2ClientBase::Camera2ClientBase(
????constsp& cameraService,
????constsp& remoteCallback,
????constString16& clientPackageName,
????constString8& cameraId,
????intcameraFacing,
????intclientPid,
????uid_tclientUid,
????intservicePid):
??? TClientBase(cameraService,remoteCallback, clientPackageName,
??????????? cameraId, cameraFacing,clientPid, clientUid, servicePid),
???mSharedCameraCallbacks(remoteCallback),
???mDeviceVersion(cameraService->getDeviceVersion(
??????????? TClientBase::mCameraIdStr)),
??? mDeviceActive(false)
{
??? ...
??? mInitialClientPid = clientPid;
????//?只要是?HAL3?，則?device?都是對應(yīng)的?Camera3Device
??? mDevice =?newCamera3Device(cameraId);
??? ...
}

從源碼可以看出，不管是 API1/2 ，只要是 HAL 3 ，Camera2Client, CameraDeviceClient 兩個客戶端對應(yīng)的都是 device3: Camera3Device 。

Camera3Device::HalInterface 內(nèi)部類，用于和 HAL 層通信，實現(xiàn)了 HAL 層 ICameraDeviceSession.hal 部分代碼：

// Camera3Device.hclassCamera3Device?:
??? ...
????classHalInterface?:?publiccamera3::Camera3StreamBufferFreedListener {
??????public:
??????? ...
????????// Calls into the HALinterface

????????// Caller takes ownershipof requestTemplate
????????status_tconstructDefaultRequestSettings(
????????????????camera3_request_template_ttemplateId,
????????????????/*out*/camera_metadata_t**requestTemplate);
????????status_tconfigureStreams(
????????????/*inout*/camera3_stream_configuration *config);
????????status_tprocessCaptureRequest(camera3_capture_request_t*request);
????????status_t?flush();
????????status_t?close();
??????? ...
??? }
??? ...
}

?原文鏈接：https://www.dazhuanlan.com/2019/10/16/5da68019bdbe3/

相關(guān)文章友情推薦?

1. Android開發(fā)干貨分享

至此，本篇已結(jié)束。轉(zhuǎn)載網(wǎng)絡(luò)的文章，小編覺得很優(yōu)秀，如有侵權(quán)，懇請聯(lián)系小編刪除，歡迎您的建議與指正。同時期待您的關(guān)注，感謝您的閱讀，謝謝！

點個在看，方便您使用時快速查看！