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!2796 驱动子系统Camera模块开发指南同步到Release分支上 

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zh-cn/device-dev/driver/driver-peripherals-camera-des.md
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# Camera<a name="ZH-CN_TOPIC_0000001078436908"></a>
# Camera
- [Camera<a name="ZH-CN_TOPIC_0000001078436908"></a>](#camera)
- [概述<a name="section11660541593"></a>](#概述)
- [开发指导<a name="section161941989596"></a>](#开发指导)
- [HDI接口说明<a name="section1551164914237"></a>](#hdi接口说明)
- [开发步骤<a name="section19806524151819"></a>](#开发步骤)
- [开发实例<a name="section1564411661810"></a>](#开发实例)
## 概述<a name="1"></a>
### 功能简介<a name="2"></a>
OpenHarmony相机驱动框架模型对上实现相机HDI（Hardware Device Interface）接口，对下实现相机Pipeline模型，管理相机各个硬件设备。
该驱动框架模型内部分为三层，依次为HDI实现层、框架层和设备适配层，各层基本概念如下：
## 概述<a name="section11660541593"></a>
+ HDI实现层：实现OHOS（OpenHarmony Operation System）相机标准南向接口。
+ 框架层：对接HDI实现层的控制、流的转发，实现数据通路的搭建，管理相机各个硬件设备等功能。
+ 设备适配层：屏蔽底层芯片和OS（Operation System）差异，支持多平台适配。
OpenHarmony相机驱动框架模型对上实现相机HDI（Hardware Driver Interface）接口，对下实现相机Pipeline模型，管理相机各个硬件设备。
该驱动框架模型内部分为三层，依次为HDI实现层、框架层和适配层，各层基本概念如下：
+ **HDI实现层**：对上实现OHOS（OpenHarmony Operation System）相机标准南向接口。
+ **框架层**：对接HDI实现层的控制、流的转发，实现数据通路的搭建，管理相机各个硬件设备等功能。
### 运作机制<a name="3"></a>
+ **适配层**：屏蔽底层芯片和OS（Operation System）差异，支持多平台适配。
Camera模块主要包含服务、设备的初始化，数据通路的搭建，流的配置、创建、下发、捕获等，具体运作机制参考以下图文解析：
**<a name="fig3672817152110"></a>**
**图 1** 基于HDF驱动框架的Camera驱动模型
![](figures/logic-view-of-camera-hal-zh.png)
**图 1** 基于HDF驱动框架的Camera驱动模型　
1. 系统启动时创建CameraDeviceHost进程。进程创建后，首先枚举底层设备，创建（也可以通过配置表创建）管理设备树的DeviceManager类及其内部各个底层设备的对象，创建对应的CameraHost类实例并且将其注册到UHDF服务中，方便上层通过UHDF服务获取底层CameraDeviceHost的服务，从而操作底层设备。
　　　　　　　　![](figures/Camera模块驱动模型.png)
2. Service通过CameraDeviceHost服务获取CameraHost实例，CameraHost可以获取底层的Camera能力，打开手电筒、调用Open接口打开Camera创建连接、创建DeviceManager（负责底层硬件模块上电）、创建CameraDevice（向上提供设备控制接口）。创建CameraDevice时会实例化PipelineCore的各个子模块，其中StreamPiplineCore负责创建Pipeline，MetaQueueManager负责上报meta。
3. Service通过底层的CameraDevice配置流、创建Stream类。StreamPipelineStrategy模块通过上层下发的模式和查询配置表创建对应流的Node连接方式，StreamPipelineBuilder模块创建Node实例并且连接返回该Pipline给StreamPipelineDispatcher。StreamPipelineDispatcher提供统一的Pipline调用管理。
1. 系统启动时创建camera_host进程。进程创建后，首先枚举底层设备，创建（也可以通过配置表创建）管理设备树的DeviceManager类及其内部各个底层设备的对象，创建对应的CameraHost类实例并且将其注册到UHDF服务中，方便相机服务层通过UHDF服务获取底层CameraDeviceHost的服务，从而操作硬件设备。
2. Service通过CameraDeviceHost服务获取CameraHost实例，CameraHost可以获取底层的Camera能力，打开手电筒、调用Open接口打开Camera创建连接、创建DeviceManager（负责底层硬件模块上电）、创建CameraDevice（向上提供设备控制接口）。创建CameraDevice时会实例化PipelineCore的各个子模块，其中StreamPipelineCore负责创建Pipeline，MetaQueueManager负责上报metaData。
3. Service通过CameraDevice模块配置流、创建Stream类。StreamPipelineStrategy模块通过上层下发的模式和查询配置表创建对应流的Node连接方式，StreamPipelineBuilder模块创建Node实例并且连接返回该Pipeline给StreamPipelineDispatcher。StreamPipelineDispatcher提供统一的Pipeline调用管理。
4. Service通过Stream控制整个流的操作，AttachBufferQueue接口将从显示模块申请的BufferQueue下发到底层，由CameraDeviceDriverModel自行管理buffer，当Capture接口下发命令后，底层开始向上传递buffer。Pipeline的IspNode依次从BufferQueue获取指定数量buffer，然后下发到底层ISP（Image Signal Processor，图像信号处理器）硬件，ISP填充完之后将buffer传递给CameraDeviceDriverModel，CameraDeviceDriverModel通过循环线程将buffer填充到已经创建好的Pipeline中，各个Node处理后通过回调传递给上层，同时buffer返回BufferQueue等待下一次下发。
......@@ -34,639 +30,710 @@ OpenHarmony相机驱动框架模型对上实现相机HDI（Hardware Driver Inter
6. Service通过CameraDevice的UpdateSettings接口向下发送CaptureSetting参数，CameraDeviceDriverModel通过StreamPipelineDispatcher模块向各个Node转发，StartStreamingCapture和Capture接口携带的CaptureSetting通过StreamPipelineDispatcher模块向该流所属的Node转发。
7. Service通过EnableResult和DisableResult接口控制底层meta的上报。如果需要底层meta上报，pipeline会创建CameraDeviceDriverModel内部的一个Bufferqueue用来收集和传递meta，根据StreamPipelineStrategy模块查询配置表并通过StreamPipelineBuilder创建和连接Node，MetaQueueManager下发buffer至底层，底层相关Node填充数据，MetaQueueManager模块再调用上层回调传递给上层。
7. Service通过EnableResult和DisableResult接口控制底层metaData的上报。如果需要底层metaData上报，pipeline会创建CameraDeviceDriverModel内部的一个Bufferqueue用来收集和传递metaData，根据StreamPipelineStrategy模块查询配置表并通过StreamPipelineBuilder创建和连接Node，MetaQueueManager下发buffer至底层，底层相关Node填充数据，MetaQueueManager模块再调用上层回调传递给上层。
8. Service调用CameraDevice的Close接口，CameraDevice调用对应的DeviceManager模块对各个硬件下电；如果此时在Ipp的SubPipeline中存在OfflineStream，则需要保留OfflineStream，直到执行完毕。
9. 动态帧率控制。在StreamOperator中起一个CollectBuffer线程，CollectBuffer线程从每一路stream的BufferQueue中获取buffer，如果某一路流的帧率需要控制（为sensor出帧帧率的1/n），可以根据需求控制每一帧的buffer打包，并决定是否collect此路流的buffer（比如sensor出帧帧率为120fps，预览流的帧率为30fps，CollectBuffer线程collect预览流的buffer时，每隔4fps collect一次）。
## 开发指导<a name="section161941989596"></a>
### HDI接口说明<a name="section1551164914237"></a>
旨在了解HDI接口的作用及函数参数的传递规则，详情可见[Camera驱动子系统HDI使用说明](https://gitee.com/openharmony/drivers_peripheral/blob/master/camera/README_zh.md)。
### 开发步骤<a name="section19806524151819"></a>
下面分步骤描述了Camera驱动框架的主要接口，包括注册、检测；创建、捕获和销毁流；打开和关闭设备等接口（为了更清晰的展示和描述主要功能的实现部分，该章节删除了部分判错和LOG源码）。
1. 注册CameraHost
定义Camera的HdfDriverEntry结构体，该结构体中定义了CameraHost初始化的方法。
```
struct HdfDriverEntry g_cameraHostDriverEntry = {
.moduleVersion = 1,
.moduleName = "camera_service",
.Bind = HdfCameraHostDriverBind,
.Init = HdfCameraHostDriverInit,
.Release = HdfCameraHostDriverRelease,
};
HDF_INIT(g_cameraHostDriverEntry); // 将Camera的HdfDriverEntry结构体注册到HDF上
```
2. CameraHost初始化
步骤1中提到的HdfCameraHostDriverBind接口提供了CameraServiceDispatch和CameraHostStubInstance的注册。这两个接口一个是远端调用CameraHost的方法，如OpenCamera()，SetFlashlight()等，另外一个是Camera设备的初始化，在开机时被调用。
```
int HdfCameraHostDriverBind(HdfDeviceObject *deviceObject)
{
HDF_LOGI("HdfCameraHostDriverBind enter!");
if (deviceObject == nullptr) {
HDF_LOGE("HdfCameraHostDriverBind: HdfDeviceObject is NULL !");
return HDF_FAILURE;
}
HdfCameraService *hdfCameraService = reinterpret_cast<HdfCameraService *>(OsalMemAlloc(sizeof(HdfCameraService)));
if (hdfCameraService == nullptr) {
HDF_LOGE("HdfCameraHostDriverBind OsalMemAlloc HdfCameraService failed!");
return HDF_FAILURE;
}
hdfCameraService->ioservice.Dispatch = CameraServiceDispatch; // 提供远端CameraHost调用方法
hdfCameraService->ioservice.Open = nullptr;
hdfCameraService->ioservice.Release = nullptr;
hdfCameraService->instance = CameraHostStubInstance(); // 初始化Camera设备
deviceObject->service = &hdfCameraService->ioservice;
return HDF_SUCCESS;
}
```
下面的函数是远端CameraHost调用的方法：
```
int32_t CameraHostStub::CameraHostServiceStubOnRemoteRequest(int cmdId, MessageParcel &data,
MessageParcel &reply, MessageOption &option)
{
switch(cmdId) {
case CMD_CAMERA_HOST_SET_CALLBACK: {
return CameraHostStubSetCallback(data, reply, option);
}
case CMD_CAMERA_HOST_GET_CAMERAID: {
return CameraHostStubGetCameraIds(data, reply, option);
}
case CMD_CAMERA_HOST_GET_CAMERA_ABILITY: {
return CameraHostStubGetCameraAbility(data, reply, option);
}
case CMD_CAMERA_HOST_OPEN_CAMERA: {
return CameraHostStubOpenCamera(data, reply, option);
}
case CMD_CAMERA_HOST_SET_FLASH_LIGHT: {
return CameraHostStubSetFlashlight(data, reply, option);
}
default: {
HDF_LOGE("%s: not support cmd %d", __func__, cmdId);
return HDF_ERR_INVALID_PARAM;
}
}
return HDF_SUCCESS;
}
```
CameraHostStubInstance()接口最终调用CameraHostImpl::Init()方法，该方法会获取物理Camera，并对DeviceManager和PipelineCore进行初始化。
9. 动态帧率控制。在StreamOperator中起一个CollectBuffer线程，CollectBuffer线程从每一路stream的BufferQueue中获取buffer，如果某一路流的帧率需要控制（为sensor出帧帧率的1/n），可以根据需求控制每一帧的buffer打包，并决定是否collect此路流的buffer（比如sensor出帧帧率为120fps，预览流的帧率为30fps，CollectBuffer线程collect预览流的buffer时，每隔4fps collect一次）。
3. 获取CamerHost
调用Get()接口从远端CameraService中获取CameraHost对象。get()方法如下：
```
sptr<ICameraHost> ICameraHost::Get(const char *serviceName)
{
do {
using namespace OHOS::HDI::ServiceManager::V1_0;
auto servMgr = IServiceManager::Get();
if (servMgr == nullptr) {
HDF_LOGE("%s: IServiceManager failed!", __func__);
break;
}
auto remote = servMgr->GetService(serviceName); // 根据serviceName名称获取CameraHost
if (remote != nullptr) {
sptr<CameraHostProxy> hostSptr = iface_cast<CameraHostProxy>(remote); // 将CameraHostProxy对象返回给调用者，该对象中包含OpenCamera()等方法。
return hostSptr;
}
HDF_LOGE("%s: GetService failed! serviceName = %s", __func__, serviceName);
} while(false);
HDF_LOGE("%s: get %s failed!", __func__, serviceName);
return nullptr;
}
```
4. OpenCamera()接口
CameraHostProxy对象中有五个方法，分别是SetCallback、GetCameraIds、GetCameraAbility、OpenCamera和SetFlashlight。下面着重描述OpenCamera接口。
CameraHostProxy的OpenCamera()接口通过CMD_CAMERA_HOST_OPEN_CAMERA调用远端CameraHostStubOpenCamera()接口并获取ICameraDevice对象。
```
CamRetCode CameraHostProxy::OpenCamera(const std::string &cameraId, const OHOS::sptr<ICameraDeviceCallback> &callback, OHOS::sptr<ICameraDevice> &pDevice)
{
int32_t ret = Remote()->SendRequest(CMD_CAMERA_HOST_REMOTE_OPEN_CAMERA, data, reply, option);
if (ret != HDF_SUCCESS) {
HDF_LOGE("%{public}s: SendRequest failed, error code is %{public}d", __func__, ret);
return INVALID_ARGUMENT;
}
CamRetCode retCode = static_cast<CamRetCode>(reply.ReadInt32());
bool flag = reply.ReadBool();
if (flag) {
sptr<IRemoteObject> remoteCameraDevice = reply.ReadRemoteObject();
if (remoteCameraDevice == nullptr) {
HDF_LOGE("%{public}s: CameraHostProxy remoteCameraDevice is null", __func__);
}
pDevice = OHOS::iface_cast<ICameraDevice>(remoteCameraDevice);
}
return retCode;
}
```
Remote()->SendRequest调用上文提到的CameraHostServiceStubOnRemoteRequest()，根据cmdId进入CameraHostStubOpenCamera()接口，最终调用CameraHostImpl::OpenCamera()，该接口获取了CameraDevice并对硬件进行上电等操作。
## 开发指导<a name="4"></a>
```
CamRetCode CameraHostImpl::OpenCamera(const std::string &cameraId, const OHOS::sptr<ICameraDeviceCallback> &callback, OHOS::sptr<ICameraDevice> &device)
{
std::shared_ptr<CameraDeviceImpl> cameraDevice = std::static_pointer_cast<CameraDeviceImpl>(itr->second);
if (cameraDevice == nullptr) {
CAMERA_LOGE("camera device is null.");
return INSUFFICIENT_RESOURCES;
}
CamRetCode ret = cameraDevice->SetCallback(callback);
if (ret != NO_ERROR) {
CAMERA_LOGW("set camera device callback faild.");
return ret;
}
CameraHostConfig *config = CameraHostConfig::GetInstance();
if (config == nullptr) {
return INVALID_ARGUMENT;
}
std::vector<std::string> phyCameraIds;
RetCode rc = config->GetPhysicCameraIds(cameraId, phyCameraIds);
if (rc != RC_OK) {
CAMERA_LOGE("get physic cameraId failed.");
return DEVICE_ERROR;
}
if (CameraPowerUp(cameraId, phyCameraIds) != RC_OK) { // 对Camera硬件上电
CAMERA_LOGE("camera powerup failed.");
CameraPowerDown(phyCameraIds);
return DEVICE_ERROR;
}
auto sptrDevice = deviceBackup_.find(cameraId);
if (sptrDevice == deviceBackup_.end()) {
deviceBackup_[cameraId] = cameraDevice.get();
}
device = deviceBackup_[cameraId];
cameraDevice->SetStatus(true);
return NO_ERROR;
}
```
5. GetStreamOperator()接口
### 场景介绍<a name="5"></a>
CameraDeviceImpl定义了GetStreamOperator、UpdateSettings、SetResultMode和GetEnabledResult等方法，获取流操作方法如下：
Camera模块主要用以相机预览、拍照、视频流等场景下对相机操作封装，使开发者更易操作相机硬件，提高开发效率。
```
CamRetCode CameraDeviceImpl::GetStreamOperator(const OHOS::sptr<IStreamOperatorCallback> &callback,
OHOS::sptr<IStreamOperator> &streamOperator)
{
if (callback == nullptr) {
CAMERA_LOGW("input callback is null.");
return INVALID_ARGUMENT;
}
spCameraDeciceCallback_ = callback;
if (spStreamOperator_ == nullptr) {
// 这里new了一个spStreamOperator对象传递给调用者，以便对stream进行各种操作。
spStreamOperator_ = new(std::nothrow) StreamOperatorImpl(spCameraDeciceCallback_, shared_from_this());
if (spStreamOperator_ == nullptr) {
CAMERA_LOGW("create stream operator failed.");
return DEVICE_ERROR;
}
ismOperator_ = spStreamOperator_;
}
streamOperator = ismOperator_;
spStreamOperator_->SetRequestCallback([this](){
cameraDeciceCallback_->OnError(REQUEST_TIMEOUT, 0);
});
}
```
### 接口说明<a name="6"></a>
6. 创建流
- icamera_device.h
调用CreateStreams创建流前需要填充StreamInfo结构体，具体内容如下：
| 功能描述 | 接口名称 |
| ---------------------------- | ------------------------------------------------------------ |
| 获取流控制器 | CamRetCode GetStreamOperator(<br/> const OHOS::sptr<IStreamOperatorCallback> &callback,<br/> OHOS::sptr<IStreamOperator> &streamOperator) |
| 更新设备控制参数 | CamRetCode UpdateSettings(const std::shared_ptr<CameraSetting> &settingss) |
| 设置Result回调模式和回调函数 | CamRetCode SetResultMode(const ResultCallbackMode &mode) |
| 获取使能的ResultMeta | CamRetCode GetEnabledResults(std::vector<MetaType> &results) |
| 使能具体的ResultMeta | CamRetCode EnableResult(const std::vector<MetaType> &results) |
| 禁止具体的ResultMeta | CamRetCode DisableResult(const std::vector<MetaType> &results) |
| 关闭Camera设备 | void Close() |
```
using StreamInfo = struct _StreamInfo {
int streamId_;
int width_; // 数据流宽
int height_; // 数据流高
int format_; // 数据流格式，如PIXEL_FMT_YCRCB_420_SP
int datasapce_;
StreamIntent intent_; // StreamIntent 如PREVIEW
bool tunneledMode_;
OHOS::sptr<OHOS::IBufferProducer> bufferQueue_; // 数据流bufferQueue可用streamCustomer->CreateProducer()接口创建
int minFrameDuration_;
EncodeType encodeType_;
};
```
- icamera_device_callback.h
CreateStreams()接口是StreamOperatorImpl类中的方法，该接口的主要作用是创建一个StreamBase对象，通过StreamBase的Init方法初始化CreateBufferPool等操作。
| 功能描述 | 接口名称 |
| ---------------------------------------------------------- | ------------------------------------------------------------ |
| 设备发生错误时调用，由调用者实现，用于返回错误信息给调用者 | void OnError(ErrorType type, int32_t errorCode) |
| 上报camera设备相关的metadata的回调 | void OnResult(uint64_t timestamp, const std::shared_ptr<CameraMetadata> &result) |
```
RetCode StreamOperatorImpl::CreateStream(const std::shared_ptr<StreamInfo>& streamInfo)
{
static std::map<StreamIntent, std::string> typeMap = {
{PREVIEW, "PREVIEW"},
{VIDEO, "VIDEO"},
{STILL_CAPTURE, "STILL_CAPTURE"},
{POST_VIEW, "POST_VIEW"}, {ANALYZE, "ANALYZE"},
{CUSTOM, "CUSTOM"}
};
auto itr = typeMap.find(streamInfo->intent_);
if (itr == typeMap.end()) {
CAMERA_LOGE("do not support stream type. [type = %{public}d]", streamInfo->intent_);
return RC_ERROR;
}
std::shared_ptr<StreamBase> stream = StreamFactory::Instance().CreateShared(itr->second); // 创建StreamBase实例
RetCode rc = stream->Init(streamInfo);
return RC_OK;
}
```
7. 配置流
- icamera_host.h
CommitStreams()是配置流的接口，必须在创建流之后调用，其主要作用是初始化Pipeline和创建Pipeline。
| 功能描述 | 接口名称 |
| ------------------------------ | ------------------------------------------------------------ |
| 设置ICameraHost回调接口 | CamRetCode SetCallback(const OHOS::sptr<ICameraHostCallback> &callback) |
| 获取当前可用的Camera设备ID列表 | CamRetCode GetCameraIds(std::vector<std::string> &cameraIds) |
| 获取Camera设备能力集合 | CamRetCode GetCameraAbility(const std::string &cameraId,<br/> std::shared_ptr<CameraAbility> &ability) |
| 打开Camera设备 | CamRetCode OpenCamera(const std::string &cameraId,<br/> const OHOS::sptr<ICameraDeviceCallback> &callback,<br/> OHOS::sptr<ICameraDevice> &device) |
| 打开或关闭闪光灯 | CamRetCode SetFlashlight(const std::string &cameraId, bool &isEnable) |
```
CamRetCode StreamOperatorImpl::CommitStreams(OperationMode mode, const std::shared_ptr<CameraStandard::CameraMetadata>& modeSetting)
{
auto cameraDevice = cameraDevice_.lock();
if (cameraDevice == nullptr) {
CAMERA_LOGE("camera device closed.");
return CAMERA_CLOSED;
}
std::shared_ptr<IPipelineCore> PipelineCore =
std::static_pointer_cast<CameraDeviceImpl>(cameraDevice)->GetPipelineCore();
if (PipelineCore == nullptr) {
CAMERA_LOGE("get pipeline core failed.");
return CAMERA_CLOSED;
}
streamPipeCore_ = PipelineCore->GetStreamPipelineCore();
if (streamPipeCore_ == nullptr) {
CAMERA_LOGE("get stream pipeline core failed.");
return DEVICE_ERROR;
}
RetCode rc = streamPipeCore_->Init(); // 对pipelinecore的初始化
if (rc != RC_OK) {
CAMERA_LOGE("stream pipeline core init failed.");
return DEVICE_ERROR;
}
rc = streamPipeCore_->CreatePipeline(mode); // 创建一个pipeline
if (rc != RC_OK) {
CAMERA_LOGE("create pipeline failed.");
return INVALID_ARGUMENT;
}
return NO_ERROR;
}
```
- icamera_host_callback.h
8. 捕获图像
| 功能描述 | 接口名称 |
| ---------------------- | ------------------------------------------------------------ |
| Camera设备状态变化上报 | void OnCameraStatus(const std::string &cameraId, CameraStatus status) |
| 闪光灯状态变化回调 | void OnFlashlightStatus(const std::string &cameraId, FlashlightStatus status) |
在调用Capture()接口前需要先填充CaptureInfo结构体，具体内容如下：
- ioffline_stream_operator.h
```
using CaptureInfo = struct _CaptureInfo {
std::vector<int> streamIds_; //需要Capture的streamIds
std::shared_ptr<CameraStandard::CameraMetadata> captureSetting_; // 这里填充camera ability 可通过CameraHost 的GetCameraAbility()接口获取
bool enableShutterCallback_;
};
```
| 功能描述 | 接口名称 |
| -------------- | ------------------------------------------------------------ |
| 取消捕获请求 | CamRetCode CancelCapture(int captureId) |
| 释放流 | CamRetCode ReleaseStreams(const std::vector<int> &streamIds) |
| 释放所有离线流 | CamRetCode Release() |
StreamOperatorImpl中的Capture方法主要调用CreateCapture()接口去捕获数据流：
- istream_operator.h
```
CamRetCode StreamOperatorImpl::Capture(int captureId, const std::shared_ptr<CaptureInfo>& captureInfo, bool isStreaming)
{
if (!ValidCaptureInfo(captureId, captureInfo)) {
CAMERA_LOGE("capture streamIds is empty. [captureId = %d]", captureId);
return INVALID_ARGUMENT;
}
std::shared_ptr<CameraCapture> cameraCapture = nullptr;
RetCode rc = CreateCapture(captureId, captureInfo, isStreaming, cameraCapture);
if (rc != RC_OK) {
CAMERA_LOGE("create capture is failed.");
return DEVICE_ERROR;
}
{
std::unique_lock<std::mutex> lock(captureMutex_);
camerCaptureMap_.insert(std::make_pair(captureId, cameraCapture));
}
rc = StartThread();
if (rc != RC_OK) {
CAMERA_LOGE("preview start failed.");
return DEVICE_ERROR;
}
return NO_ERROR;
}
```
| 功能描述 | 接口名称 |
| -------------------------------- | ------------------------------------------------------------ |
| 查询是否支持添加参数对应的流 | CamRetCode IsStreamsSupported(<br/> OperationMode mode,<br/> const std::shared_ptr<CameraStandard::CameraMetadata> &modeSetting,<br/> const std::vector&ltstd::shared_ptr&ltStreamInfo&gt> &info,<br/> StreamSupportType &type) |
| 创建流 | CamRetCode CreateStreams(const std::vector<std::shared_ptr<StreamInfo>> &streamInfos) |
| 释放流 | CamRetCode ReleaseStreams(const std::vector<int> &streamIds) |
| 配置流 | CamRetCode CommitStreams(OperationMode mode,<br/> const std::shared_ptr<CameraMetadata> &modeSetting) |
| 获取流的属性 | CamRetCode GetStreamAttributes(<br/> std::vector<std::shared_ptr<StreamAttribute>> &attributes) |
| 绑定生产者句柄和指定流 | CamRetCode AttachBufferQueue(int streamId, const OHOS::sptr<OHOS::IBufferProducer> &producer) |
| 解除生产者句柄和指定流的绑定关系 | CamRetCode DetachBufferQueue(int streamId) |
| 捕获图像 | CamRetCode Capture(int captureId,<br/> const std::shared_ptr<CaptureInfo> &info, bool isStreaming) |
| 取消捕获 | CamRetCode CancelCapture(int captureId) |
| 将指定流转换成离线流 | CamRetCode ChangeToOfflineStream(const std::vector<int> &streamIds,<br/> OHOS::sptr<IStreamOperatorCallback> &callback,<br/> OHOS::sptr<IOfflineStreamOperator> &offlineOperator) |
9. 取消捕获和释放离线流
- istream_operator_callback.h
StreamOperatorImpl类中的CancelCapture()接口的主要作用是根据captureId取消数据流的捕获。
| 功能描述 | 接口名称 |
| ---------------------------------------- | ------------------------------------------------------------ |
| 捕获开始回调，在捕获开始时调用 | void OnCaptureStarted(int32_t captureId, const std::vector<int32_t> &streamIds) |
| 捕获结束回调，在捕获结束时调用 | void OnCaptureEnded(int32_t captureId,<br/> const std::vector<std::shared_ptr<CaptureEndedInfo>> &infos) |
| 捕获错误回调，在捕获过程中发生错误时调用 | void OnCaptureError(int32_t captureId,<br/> const std::vector<std::shared_ptr<CaptureErrorInfo>> &infos) |
| 帧捕获回调 | void OnFrameShutter(int32_t captureId,<br/> const std::vector<int32_t> &streamIds, uint64_t timestamp) |
```
CamRetCode StreamOperatorImpl::CancelCapture(int captureId)
{
auto itr = camerCaptureMap_.find(captureId); //根据captureId 在Map中查找对应的CameraCapture对象
RetCode rc = itr->second->Cancel(); //调用CameraCapture中Cancel方法结束数据捕获
std::unique_lock<std::mutex> lock(captureMutex_);
camerCaptureMap_.erase(itr); //擦除该CameraCapture对象
return NO_ERROR;
}
```
### 开发步骤<a name="7"></a>
Camera驱动的开发过程主要包含以下步骤：
StreamOperatorImpl类中的ReleaseStreams接口的主要作用是释放之前通过CreateStream()和CommitStreams()接口创建的流，并销毁Pipeline。
1. **注册CameraHost**
定义Camera的HdfDriverEntry结构体，该结构体中定义了CameraHost初始化的方法。
```
CamRetCode StreamOperatorImpl::ReleaseStreams(const std::vector<int>& streamIds)
{
RetCode rc = DestroyStreamPipeline(streamIds); //销毁该streamIds 的pipeline
rc = DestroyHostStreamMgr(streamIds);
rc = DestroyStreams(streamIds); //销毁该streamIds 的 Stream
return NO_ERROR;
}
```
10. 关闭Camera设备
struct HdfDriverEntry g_cameraHostDriverEntry = {
.moduleVersion = 1,
.moduleName = "camera_service",
.Bind = HdfCameraHostDriverBind,
.Init = HdfCameraHostDriverInit,
.Release = HdfCameraHostDriverRelease,
};
HDF_INIT(g_cameraHostDriverEntry); // 将Camera的HdfDriverEntry结构体注册到HDF上
```
调用CameraDeviceImpl中的Close()来关闭CameraDevice，该接口调用deviceManager中的PowerDown()来给设备下电。
2. **初始化Host服务**
步骤1中提到的HdfCameraHostDriverBind接口提供了CameraServiceDispatch和CameraHostStubInstance的注册。这两个接口一个是远端调用CameraHost的方法，如OpenCamera()，SetFlashlight()等，另外一个是Camera设备的初始化，在开机时被调用。
## 开发实例<a name="section1564411661810"></a>
在/drivers/peripheral/camera/hal/init目录下有一个关于Camera的demo，开机后会在/system/bin下生成可执行文件ohos_camera_demo，该demo可以完成camera的预览，拍照等基础功能。下面我们就以此demo为例讲述怎样用HDI接口去编写预览PreviewOn()和拍照CaptureON()的用例。
1. 在main函数中构造一个Hos3516Demo对象，该对象中有对camera初始化、启停流、释放等控制的方法。下面mainDemo->InitSensors()函数为初始化CameraHost，mainDemo->InitCameraDevice()函数为初始化CameraDevice。
```
int main(int argc, char** argv)
{
RetCode rc = RC_OK;
auto mainDemo = std::make_shared<Hos3516Demo>();
rc = mainDemo->InitSensors(); // 初始化CameraHost
if (rc == RC_ERROR) {
CAMERA_LOGE("main test: mainDemo->InitSensors() error\n");
return -1;
}
rc = mainDemo->InitCameraDevice(); // 初始化CameraDevice
if (rc == RC_ERROR) {
CAMERA_LOGE("main test: mainDemo->InitCameraDevice() error\n");
return -1;
}
rc = PreviewOn(0, mainDemo); // 配流和启流
if (rc != RC_OK) {
CAMERA_LOGE("main test: PreviewOn() error demo exit");
return -1;
}
ManuList(mainDemo, argc, argv); // 打印菜单到控制台
```
int HdfCameraHostDriverBind(HdfDeviceObject *deviceObject)
{
HDF_LOGI("HdfCameraHostDriverBind enter!");
if (deviceObject == nullptr) {
HDF_LOGE("HdfCameraHostDriverBind: HdfDeviceObject is NULL !");
return HDF_FAILURE;
}
HdfCameraService *hdfCameraService = reinterpret_cast<HdfCameraService *>(OsalMemAlloc(sizeof(HdfCameraService)));
if (hdfCameraService == nullptr) {
HDF_LOGE("HdfCameraHostDriverBind OsalMemAlloc HdfCameraService failed!");
return HDF_FAILURE;
}
hdfCameraService->ioservice.Dispatch = CameraServiceDispatch; // 提供远端CameraHost调用方法
hdfCameraService->ioservice.Open = nullptr;
hdfCameraService->ioservice.Release = nullptr;
hdfCameraService->instance = CameraHostStubInstance(); // 初始化Camera设备
deviceObject->service = &hdfCameraService->ioservice;
return HDF_SUCCESS;
}
```
下面的函数是远端CameraHost调用的方法：
```
int32_t CameraHostStub::CameraHostServiceStubOnRemoteRequest(int cmdId, MessageParcel &data,
MessageParcel &reply, MessageOption &option)
{
switch(cmdId) {
case CMD_CAMERA_HOST_SET_CALLBACK: {
return CameraHostStubSetCallback(data, reply, option);
}
case CMD_CAMERA_HOST_GET_CAMERAID: {
return CameraHostStubGetCameraIds(data, reply, option);
}
case CMD_CAMERA_HOST_GET_CAMERA_ABILITY: {
return CameraHostStubGetCameraAbility(data, reply, option);
}
case CMD_CAMERA_HOST_OPEN_CAMERA: {
return CameraHostStubOpenCamera(data, reply, option);
}
case CMD_CAMERA_HOST_SET_FLASH_LIGHT: {
return CameraHostStubSetFlashlight(data, reply, option);
}
default: {
HDF_LOGE("%s: not support cmd %d", __func__, cmdId);
return HDF_ERR_INVALID_PARAM;
}
}
return HDF_SUCCESS;
}
```
CameraHostStubInstance()接口最终调用CameraHostImpl::Init()方法，该方法会获取物理Camera，并对DeviceManager和PipelineCore进行初始化。
3. **获取Host服务**
调用Get()接口从远端CameraService中获取CameraHost对象。get()方法如下：
```
sptr<ICameraHost> ICameraHost::Get(const char *serviceName)
{
do {
using namespace OHOS::HDI::ServiceManager::V1_0;
auto servMgr = IServiceManager::Get();
if (servMgr == nullptr) {
HDF_LOGE("%s: IServiceManager failed!", __func__);
break;
}
auto remote = servMgr->GetService(serviceName); // 根据serviceName名称获取CameraHost
if (remote != nullptr) {
sptr<CameraHostProxy> hostSptr = iface_cast<CameraHostProxy>(remote); // 将CameraHostProxy对象返回给调用者，该对象中包含OpenCamera()等方法。
return hostSptr;
}
HDF_LOGE("%s: GetService failed! serviceName = %s", __func__, serviceName);
} while(false);
HDF_LOGE("%s: get %s failed!", __func__, serviceName);
return nullptr;
}
```
4. **打开设备**
CameraHostProxy对象中有五个方法，分别是SetCallback、GetCameraIds、GetCameraAbility、OpenCamera和SetFlashlight。下面着重描述OpenCamera接口。
CameraHostProxy的OpenCamera()接口通过CMD_CAMERA_HOST_OPEN_CAMERA调用远端CameraHostStubOpenCamera()接口并获取ICameraDevice对象。
```
CamRetCode CameraHostProxy::OpenCamera(const std::string &cameraId, const OHOS::sptr<ICameraDeviceCallback> &callback, OHOS::sptr<ICameraDevice> &pDevice)
{
int32_t ret = Remote()->SendRequest(CMD_CAMERA_HOST_REMOTE_OPEN_CAMERA, data, reply, option);
if (ret != HDF_SUCCESS) {
HDF_LOGE("%{public}s: SendRequest failed, error code is %{public}d", __func__, ret);
return INVALID_ARGUMENT;
}
CamRetCode retCode = static_cast<CamRetCode>(reply.ReadInt32());
bool flag = reply.ReadBool();
if (flag) {
sptr<IRemoteObject> remoteCameraDevice = reply.ReadRemoteObject();
if (remoteCameraDevice == nullptr) {
HDF_LOGE("%{public}s: CameraHostProxy remoteCameraDevice is null", __func__);
}
pDevice = OHOS::iface_cast<ICameraDevice>(remoteCameraDevice);
}
return retCode;
}
```
Remote()->SendRequest调用上文提到的CameraHostServiceStubOnRemoteRequest()，根据cmdId进入CameraHostStubOpenCamera()接口，最终调用CameraHostImpl::OpenCamera()，该接口获取了CameraDevice并对硬件进行上电等操作。
```
CamRetCode CameraHostImpl::OpenCamera(const std::string &cameraId, const OHOS::sptr<ICameraDeviceCallback> &callback, OHOS::sptr<ICameraDevice> &device)
{
std::shared_ptr<CameraDeviceImpl> cameraDevice = std::static_pointer_cast<CameraDeviceImpl>(itr->second);
if (cameraDevice == nullptr) {
CAMERA_LOGE("camera device is null.");
return INSUFFICIENT_RESOURCES;
}
CamRetCode ret = cameraDevice->SetCallback(callback);
if (ret != NO_ERROR) {
CAMERA_LOGW("set camera device callback failed.");
return ret;
}
CameraHostConfig *config = CameraHostConfig::GetInstance();
if (config == nullptr) {
return INVALID_ARGUMENT;
}
std::vector<std::string> phyCameraIds;
RetCode rc = config->GetPhysicCameraIds(cameraId, phyCameraIds);
if (rc != RC_OK) {
CAMERA_LOGE("get physic cameraId failed.");
return DEVICE_ERROR;
}
if (CameraPowerUp(cameraId, phyCameraIds) != RC_OK) { // 对Camera硬件上电
CAMERA_LOGE("camera powerup failed.");
CameraPowerDown(phyCameraIds);
return DEVICE_ERROR;
}
auto sptrDevice = deviceBackup_.find(cameraId);
if (sptrDevice == deviceBackup_.end()) {
deviceBackup_[cameraId] = cameraDevice.get();
}
device = deviceBackup_[cameraId];
cameraDevice->SetStatus(true);
return NO_ERROR;
}
```
5. **获取流**
CameraDeviceImpl定义了GetStreamOperator、UpdateSettings、SetResultMode和GetEnabledResult等方法，获取流操作方法如下：
```
CamRetCode CameraDeviceImpl::GetStreamOperator(const OHOS::sptr<IStreamOperatorCallback> &callback,
OHOS::sptr<IStreamOperator> &streamOperator)
{
if (callback == nullptr) {
CAMERA_LOGW("input callback is null.");
return INVALID_ARGUMENT;
}
spCameraDeviceCallback_ = callback;
if (spStreamOperator_ == nullptr) {
// 这里new了一个spStreamOperator对象传递给调用者，以便对stream进行各种操作。
spStreamOperator_ = new(std::nothrow) StreamOperatorImpl(spCameraDeviceCallback_, shared_from_this());
if (spStreamOperator_ == nullptr) {
CAMERA_LOGW("create stream operator failed.");
return DEVICE_ERROR;
}
ismOperator_ = spStreamOperator_;
}
streamOperator = ismOperator_;
spStreamOperator_->SetRequestCallback([this](){
spCameraDeviceCallback_->OnError(REQUEST_TIMEOUT, 0);
});
}
```
6. **创建流**
调用CreateStreams创建流前需要填充StreamInfo结构体，具体内容如下：
```
using StreamInfo = struct _StreamInfo {
int streamId_;
int width_; // 数据流宽
int height_; // 数据流高
int format_; // 数据流格式，如PIXEL_FMT_YCRCB_420_SP
int dataSpace_;
StreamIntent intent_; // StreamIntent 如PREVIEW
bool tunneledMode_;
OHOS::sptr<OHOS::IBufferProducer> bufferQueue_; // 数据流bufferQueue可用streamCustomer->CreateProducer()接口创建
int minFrameDuration_;
EncodeType encodeType_;
};
```
CreateStreams()接口是StreamOperatorImpl类中的方法，该接口的主要作用是创建一个StreamBase对象，通过StreamBase的Init方法初始化CreateBufferPool等操作。
```
RetCode StreamOperatorImpl::CreateStream(const std::shared_ptr<StreamInfo>& streamInfo)
{
static std::map<StreamIntent, std::string> typeMap = {
{PREVIEW, "PREVIEW"},
{VIDEO, "VIDEO"},
{STILL_CAPTURE, "STILL_CAPTURE"},
{POST_VIEW, "POST_VIEW"}, {ANALYZE, "ANALYZE"},
{CUSTOM, "CUSTOM"}
};
auto itr = typeMap.find(streamInfo->intent_);
if (itr == typeMap.end()) {
CAMERA_LOGE("do not support stream type. [type = %{public}d]", streamInfo->intent_);
return RC_ERROR;
}
std::shared_ptr<StreamBase> stream = StreamFactory::Instance().CreateShared(itr->second); // 创建StreamBase实例
RetCode rc = stream->Init(streamInfo);
return RC_OK;
}
```
7. **配置流**
CommitStreams()是配置流的接口，必须在创建流之后调用，其主要作用是初始化Pipeline和创建Pipeline。
```
CamRetCode StreamOperatorImpl::CommitStreams(OperationMode mode, const std::shared_ptr<CameraStandard::CameraMetadata>& modeSetting)
{
auto cameraDevice = cameraDevice_.lock();
if (cameraDevice == nullptr) {
CAMERA_LOGE("camera device closed.");
return CAMERA_CLOSED;
}
std::shared_ptr<IPipelineCore> PipelineCore =
std::static_pointer_cast<CameraDeviceImpl>(cameraDevice)->GetPipelineCore();
if (PipelineCore == nullptr) {
CAMERA_LOGE("get pipeline core failed.");
return CAMERA_CLOSED;
}
streamPipeCore_ = PipelineCore->GetStreamPipelineCore();
if (streamPipeCore_ == nullptr) {
CAMERA_LOGE("get stream pipeline core failed.");
return DEVICE_ERROR;
}
RetCode rc = streamPipeCore_->Init(); // 对pipelinecore的初始化
if (rc != RC_OK) {
CAMERA_LOGE("stream pipeline core init failed.");
return DEVICE_ERROR;
}
rc = streamPipeCore_->CreatePipeline(mode); // 创建一个pipeline
if (rc != RC_OK) {
CAMERA_LOGE("create pipeline failed.");
return INVALID_ARGUMENT;
}
return NO_ERROR;
}
```
8. **捕获图像**
在调用Capture()接口前需要先填充CaptureInfo结构体，具体内容如下：
```
using CaptureInfo = struct _CaptureInfo {
std::vector<int> streamIds_; //需要Capture的streamIds
std::shared_ptr<CameraStandard::CameraMetadata> captureSetting_; // 这里填充camera ability 可通过CameraHost 的GetCameraAbility()接口获取
bool enableShutterCallback_;
};
```
StreamOperatorImpl中的Capture方法主要调用CreateCapture()接口去捕获数据流：
```
CamRetCode StreamOperatorImpl::Capture(int captureId, const std::shared_ptr<CaptureInfo>& captureInfo, bool isStreaming)
{
if (!ValidCaptureInfo(captureId, captureInfo)) {
CAMERA_LOGE("capture streamIds is empty. [captureId = %d]", captureId);
return INVALID_ARGUMENT;
}
std::shared_ptr<CameraCapture> cameraCapture = nullptr;
RetCode rc = CreateCapture(captureId, captureInfo, isStreaming, cameraCapture);
if (rc != RC_OK) {
CAMERA_LOGE("create capture is failed.");
return DEVICE_ERROR;
}
{
std::unique_lock<std::mutex> lock(captureMutex_);
camerCaptureMap_.insert(std::make_pair(captureId, cameraCapture));
}
rc = StartThread();
if (rc != RC_OK) {
CAMERA_LOGE("preview start failed.");
return DEVICE_ERROR;
}
return NO_ERROR;
}
```
9. **取消捕获和释放离线流**
StreamOperatorImpl类中的CancelCapture()接口的主要作用是根据captureId取消数据流的捕获。
```
CamRetCode StreamOperatorImpl::CancelCapture(int captureId)
{
auto itr = camerCaptureMap_.find(captureId); //根据captureId 在Map中查找对应的CameraCapture对象
RetCode rc = itr->second->Cancel(); //调用CameraCapture中Cancel方法结束数据捕获
std::unique_lock<std::mutex> lock(captureMutex_);
camerCaptureMap_.erase(itr); //擦除该CameraCapture对象
return NO_ERROR;
}
```
StreamOperatorImpl类中的ReleaseStreams接口的主要作用是释放之前通过CreateStream()和CommitStreams()接口创建的流，并销毁Pipeline。
```
CamRetCode StreamOperatorImpl::ReleaseStreams(const std::vector<int>& streamIds)
{
RetCode rc = DestroyStreamPipeline(streamIds); //销毁该streamIds 的pipeline
rc = DestroyHostStreamMgr(streamIds);
rc = DestroyStreams(streamIds); //销毁该streamIds 的 Stream
return NO_ERROR;
}
```
10. **关闭Camera设备**
return RC_OK;
}
```
调用CameraDeviceImpl中的Close()来关闭CameraDevice，该接口调用deviceManager中的PowerDown()来给设备下电。
初始化CameraHost函数实现如下，这里调用了HDI接口ICameraHost::Get()去获取demoCameraHost，并对其设置回调函数。
### 开发实例<a name = "8"></a>
```
RetCode Hos3516Demo::InitSensors()
{
demoCameraHost_ = ICameraHost::Get(DEMO_SERVICE_NAME);
if (demoCameraHost_ == nullptr) {
CAMERA_LOGE("demo test: ICameraHost::Get error");
return RC_ERROR;
}
hostCallback_ = new CameraHostCallback();
rc = demoCameraHost_->SetCallback(hostCallback_);
return RC_OK;
}
```
在/drivers/peripheral/camera/hal/init目录下有一个关于Camera的demo，开机后会在/vendor/bin下生成可执行文件ohos_camera_demo，该demo可以完成Ｃamera的预览，拍照等基础功能。下面我们就以此demo为例讲述怎样用HDI接口去编写预览PreviewOn()和拍照CaptureON()的用例，可参考[ohos_camera_demo](https://gitee.com/openharmony/drivers_peripheral/tree/master/camera/hal/init)。
初始化CameraDevice函数实现如下，这里调用了GetCameraIds(cameraIds_)，GetCameraAbility(cameraId, ability_)，OpenCamera(cameraIds_.front(), callback, demoCameraDevice_)等接口实现了demoCameraHost的获取。
1. 在main函数中构造一个CameraDemo 对象，该对象中有对Ｃamera初始化、启停流、释放等控制的方法。下面mainDemo->InitSensors()函数为初始化CameraHost，mainDemo->InitCameraDevice()函数为初始化CameraDevice。
```
RetCode Hos3516Demo::InitCameraDevice()
{
(void)demoCameraHost_->GetCameraIds(cameraIds_);
const std::string cameraId = cameraIds_.front();
demoCameraHost_->GetCameraAbility(cameraId, ability_);
sptr<CameraDeviceCallback> callback = new CameraDeviceCallback();
rc = demoCameraHost_->OpenCamera(cameraIds_.front(), callback, demoCameraDevice_);
return RC_OK;
}
```
```
int main(int argc, char** argv)
{
RetCode rc = RC_OK;
auto mainDemo = std::make_shared<CameraDemo>();
rc = mainDemo->InitSensors(); // 初始化CameraHost
if (rc == RC_ERROR) {
CAMERA_LOGE("main test: mainDemo->InitSensors() error\n");
return -1;
}
rc = mainDemo->InitCameraDevice(); // 初始化CameraDevice
if (rc == RC_ERROR) {
CAMERA_LOGE("main test: mainDemo->InitCameraDevice() error\n");
return -1;
}
rc = PreviewOn(0, mainDemo); // 配流和启流
if (rc != RC_OK) {
CAMERA_LOGE("main test: PreviewOn() error demo exit");
return -1;
}
ManuList(mainDemo, argc, argv); // 打印菜单到控制台
return RC_OK;
}
```
初始化CameraHost函数实现如下，这里调用了HDI接口ICameraHost::Get()去获取demoCameraHost，并对其设置回调函数。
```
RetCode CameraDemo::InitSensors()
{
demoCameraHost_ = ICameraHost::Get(DEMO_SERVICE_NAME);
if (demoCameraHost_ == nullptr) {
CAMERA_LOGE("demo test: ICameraHost::Get error");
return RC_ERROR;
}
hostCallback_ = new CameraHostCallback();
rc = demoCameraHost_->SetCallback(hostCallback_);
return RC_OK;
}
```
初始化CameraDevice函数实现如下，这里调用了GetCameraIds(cameraIds_)，GetCameraAbility(cameraId, ability_)，OpenCamera(cameraIds_.front(), callback, demoCameraDevice_)等接口实现了demoCameraHost的获取。
```
RetCode CameraDemo::InitCameraDevice()
{
(void)demoCameraHost_->GetCameraIds(cameraIds_);
const std::string cameraId = cameraIds_.front();
demoCameraHost_->GetCameraAbility(cameraId, ability_);
sptr<CameraDeviceCallback> callback = new CameraDeviceCallback();
rc = demoCameraHost_->OpenCamera(cameraIds_.front(), callback, demoCameraDevice_);
return RC_OK;
}
```
2. PreviewOn()接口包含配置流、开启预览流和启动Capture动作。该接口执行完成后Camera预览通路已经开始运转并开启了两路流，一路流是preview，另外一路流是capture或者video，两路流中仅对preview流进行capture动作。
```
static RetCode PreviewOn(int mode, const std::shared_ptr<Hos3516Demo>& mainDemo)
{
rc = mainDemo->StartPreviewStream(); // 配置preview流
if (mode == 0) {
rc = mainDemo->StartCaptureStream(); // 配置capture流
} else {
rc = mainDemo->StartVideoStream(); // 配置video流
}
rc = mainDemo->CaptureON(STREAM_ID_PREVIEW, CAPTURE_ID_PREVIEW, CAPTURE_PREVIEW); // 将preview流capture
return RC_OK;
}
```
StartCaptureStream()、StartVideoStream()和StartPreviewStream()接口都会调用CreateStream()接口，只是传入的参数不同。
```
RetCode Hos3516Demo::StartVideoStream()
{
RetCode rc = RC_OK;
if (isVideoOn_ == 0) {
isVideoOn_ = 1;
rc = CreateStream(STREAM_ID_VIDEO, streamCustomerVideo_, VIDEO); // 如需启preview或者capture流更改该接口参数即可。
}
return RC_OK;
}
```
CreateStream()方法调用HDI接口去配置和创建流，首先调用HDI接口去获取StreamOperation对象，然后创建一个StreamInfo。调用CreateStreams()和CommitStreams()实际创建流并配置流。
```
RetCode Hos3516Demo::CreateStreams(const int streamIdSecond, StreamIntent intent)
{
std::vector<std::shared_ptr<StreamInfo>> streamInfos;
std::vector<std::shared_ptr<StreamInfo>>().swap(streamInfos);
GetStreamOpt(); // 获取StreamOperator对象
std::shared_ptr<StreamInfo> previewStreamInfo = std::make_shared<StreamInfo>();
SetStreamInfo(previewStreamInfo, streamCustomerPreview_, STREAM_ID_PREVIEW, PREVIEW); // 填充StreamInfo
if (previewStreamInfo->bufferQueue_ == nullptr) {
CAMERA_LOGE("demo test: CreateStream CreateProducer(); is nullptr\n");
return RC_ERROR;
}
streamInfos.push_back(previewStreamInfo);
std::shared_ptr<StreamInfo> secondStreamInfo = std::make_shared<StreamInfo>();
if (streamIdSecond == STREAM_ID_CAPTURE) {
SetStreamInfo(secondStreamInfo, streamCustomerCapture_, STREAM_ID_CAPTURE, intent);
} else {
SetStreamInfo(secondStreamInfo, streamCustomerVideo_, STREAM_ID_VIDEO, intent);
}
if (secondStreamInfo->bufferQueue_ == nullptr) {
CAMERA_LOGE("demo test: CreateStreams CreateProducer() secondStreamInfo is nullptr\n");
return RC_ERROR;
}
streamInfos.push_back(secondStreamInfo);
rc = streamOperator_->CreateStreams(streamInfos); // 创建流
if (rc != Camera::NO_ERROR) {
CAMERA_LOGE("demo test: CreateStream CreateStreams error\n");
return RC_ERROR;
}
rc = streamOperator_->CommitStreams(Camera::NORMAL, ability_);
if (rc != Camera::NO_ERROR) {
CAMERA_LOGE("demo test: CreateStream CommitStreams error\n");
std::vector<int> streamIds = {STREAM_ID_PREVIEW, streamIdSecond};
streamOperator_->ReleaseStreams(streamIds);
return RC_ERROR;
}
return RC_OK;
}
```
CaptureON()接口调用streamOperator的Capture()方法获取camera数据并轮转buffer，拉起一个线程接收相应类型的数据。
```
RetCode Hos3516Demo::CaptureON(const int streamId, const int captureId, CaptureMode mode)
{
std::shared_ptr<Camera::CaptureInfo> captureInfo = std::make_shared<Camera::CaptureInfo>(); // 创建并填充CaptureInfo
captureInfo->streamIds_ = {streamId};
captureInfo->captureSetting_ = ability_;
captureInfo->enableShutterCallback_ = false;
int rc = streamOperator_->Capture(captureId, captureInfo, true); // 实际capture开始，buffer轮转开始
if (mode == CAPTURE_PREVIEW) {
streamCustomerPreview_->ReceiveFrameOn(nullptr); // 创建预览线程接收递上来的buffer
} else if (mode == CAPTURE_SNAPSHOT) {
streamCustomerCapture_->ReceiveFrameOn([this](void* addr, const uint32_t size) { // 创建capture线程通过StoreImage回调接收递上来的buffer
StoreImage(addr, size);
});
} else if (mode == CAPTURE_VIDEO) {
OpenVideoFile();
streamCustomerVideo_->ReceiveFrameOn([this](void* addr, const uint32_t size) {// 创建Video线程通过StoreVideo回调接收递上来的buffer
StoreVideo(addr, size);
});
}
return RC_OK;
}
```
```
static RetCode PreviewOn(int mode, const std::shared_ptr<CameraDemo>& mainDemo)
{
rc = mainDemo->StartPreviewStream(); // 配置preview流
if (mode == 0) {
rc = mainDemo->StartCaptureStream(); // 配置capture流
} else {
rc = mainDemo->StartVideoStream(); // 配置video流
}
rc = mainDemo->CaptureON(STREAM_ID_PREVIEW, CAPTURE_ID_PREVIEW, CAPTURE_PREVIEW); // 将preview流capture
return RC_OK;
}
```
StartCaptureStream()、StartVideoStream()和StartPreviewStream()接口都会调用CreateStream()接口，只是传入的参数不同。
```
RetCode CameraDemo::StartVideoStream()
{
RetCode rc = RC_OK;
if (isVideoOn_ == 0) {
isVideoOn_ = 1;
rc = CreateStream(STREAM_ID_VIDEO, streamCustomerVideo_, VIDEO); // 如需启preview或者capture流更改该接口参数即可。
}
return RC_OK;
}
```
CreateStream()方法调用HDI接口去配置和创建流，首先调用HDI接口去获取StreamOperation对象，然后创建一个StreamInfo。调用CreateStreams()和CommitStreams()实际创建流并配置流。
```
RetCode CameraDemo::CreateStreams(const int streamIdSecond, StreamIntent intent)
{
std::vector<std::shared_ptr<StreamInfo>> streamInfos;
std::vector<std::shared_ptr<StreamInfo>>().swap(streamInfos);
GetStreamOpt(); // 获取StreamOperator对象
std::shared_ptr<StreamInfo> previewStreamInfo = std::make_shared<StreamInfo>();
SetStreamInfo(previewStreamInfo, streamCustomerPreview_, STREAM_ID_PREVIEW, PREVIEW); // 填充StreamInfo
if (previewStreamInfo->bufferQueue_ == nullptr) {
CAMERA_LOGE("demo test: CreateStream CreateProducer(); is nullptr\n");
return RC_ERROR;
}
streamInfos.push_back(previewStreamInfo);
std::shared_ptr<StreamInfo> secondStreamInfo = std::make_shared<StreamInfo>();
if (streamIdSecond == STREAM_ID_CAPTURE) {
SetStreamInfo(secondStreamInfo, streamCustomerCapture_, STREAM_ID_CAPTURE, intent);
} else {
SetStreamInfo(secondStreamInfo, streamCustomerVideo_, STREAM_ID_VIDEO, intent);
}
if (secondStreamInfo->bufferQueue_ == nullptr) {
CAMERA_LOGE("demo test: CreateStreams CreateProducer() secondStreamInfo is nullptr\n");
return RC_ERROR;
}
streamInfos.push_back(secondStreamInfo);
rc = streamOperator_->CreateStreams(streamInfos); // 创建流
if (rc != Camera::NO_ERROR) {
CAMERA_LOGE("demo test: CreateStream CreateStreams error\n");
return RC_ERROR;
}
rc = streamOperator_->CommitStreams(Camera::NORMAL, ability_);
if (rc != Camera::NO_ERROR) {
CAMERA_LOGE("demo test: CreateStream CommitStreams error\n");
std::vector<int> streamIds = {STREAM_ID_PREVIEW, streamIdSecond};
streamOperator_->ReleaseStreams(streamIds);
return RC_ERROR;
}
return RC_OK;
}
```
CaptureON()接口调用streamOperator的Capture()方法获取Ｃamera数据并轮转buffer，拉起一个线程接收相应类型的数据。
```
RetCode CameraDemo::CaptureON(const int streamId, const int captureId, CaptureMode mode)
{
std::shared_ptr<Camera::CaptureInfo> captureInfo = std::make_shared<Camera::CaptureInfo>(); // 创建并填充CaptureInfo
captureInfo->streamIds_ = {streamId};
captureInfo->captureSetting_ = ability_;
captureInfo->enableShutterCallback_ = false;
int rc = streamOperator_->Capture(captureId, captureInfo, true); // 实际capture开始，buffer轮转开始
if (mode == CAPTURE_PREVIEW) {
streamCustomerPreview_->ReceiveFrameOn(nullptr); // 创建预览线程接收递上来的buffer
} else if (mode == CAPTURE_SNAPSHOT) {
streamCustomerCapture_->ReceiveFrameOn([this](void* addr, const uint32_t size) { // 创建capture线程通过StoreImage回调接收递上来的buffer
StoreImage(addr, size);
});
} else if (mode == CAPTURE_VIDEO) {
OpenVideoFile();
streamCustomerVideo_->ReceiveFrameOn([this](void* addr, const uint32_t size) {// 创建Video线程通过StoreVideo回调接收递上来的buffer
StoreVideo(addr, size);
});
}
return RC_OK;
}
```
3. ManuList()函数从控制台通过fgets()接口获取字符，不同字符所对应demo支持的功能不同，并打印出该demo所支持功能的菜单。
```
static void ManuList(const std::shared_ptr<Hos3516Demo>& mainDemo,
const int argc, char** argv)
{
int idx, c;
int awb = 1;
constexpr char shortOptions[] = "h:cwvaqof:";
c = getopt_long(argc, argv, shortOptions, longOptions, &idx);
while(1) {
switch (c) {
case 'h':
c = PutMenuAndGetChr(); // 打印菜单
break;
case 'f':
FlashLightTest(mainDemo); // 手电筒功能测试
c = PutMenuAndGetChr();
break;
case 'o':
OfflineTest(mainDemo); // Offline功能测试
c = PutMenuAndGetChr();
break;
case 'c':
CaptureTest(mainDemo); // Capture功能测试
c = PutMenuAndGetChr();
break;
case 'w': // AWB功能测试
if (awb) {
mainDemo->SetAwbMode(OHOS_CAMERA_AWB_MODE_INCANDESCENT);
} else {
mainDemo->SetAwbMode(OHOS_CAMERA_AWB_MODE_OFF);
}
awb = !awb;
c = PutMenuAndGetChr();
break;
case 'a': // AE功能测试
mainDemo->SetAeExpo();
c = PutMenuAndGetChr();
break;
case 'v': // Video功能测试
VideoTest(mainDemo);
c = PutMenuAndGetChr();
break;
case 'q': // 退出demo
PreviewOff(mainDemo);
mainDemo->QuitDemo();
exit(EXIT_SUCCESS);
default:
CAMERA_LOGE("main test: command error please retry input command");
c = PutMenuAndGetChr();
break;
}
}
}
```
PutMenuAndGetChr()接口打印了demo程序的菜单，并调用fgets()等待从控制台输入命令，内容如下：
```
static int PutMenuAndGetChr(void)
{
constexpr uint32_t inputCount = 50;
int c = 0;
char strs[inputCount];
Usage(stdout);
CAMERA_LOGD("pls input command(input -q exit this app)\n");
fgets(strs, inputCount, stdin);
for (int i = 0; i < inputCount; i++) {
if (strs[i] != '-') {
c = strs[i];
break;
}
}
return c;
}
```
控制台输出菜单详情如下：
```
"Options:\n"
"-h | --help Print this message\n"
"-o | --offline stream offline test\n"
"-c | --capture capture one picture\n"
"-w | --set WB Set white balance Cloudy\n"
"-v | --video capture Viedeo of 10s\n"
"-a | --Set AE Set Auto exposure\n"
"-f | --Set Flashlight Set flashlight ON 5s OFF\n"
"-q | --quit stop preview and quit this app\n");
```
demo中其他功能会调用不同的HDI接口去实现，与PreviewOn()接口类似，这里不再赘述，具体详情可以参见[ohos_camera_demo](https://gitee.com/openharmony/drivers_peripheral/tree/master/camera/hal/init)。
```
static void ManuList(const std::shared_ptr<CameraDemo>& mainDemo,
const int argc, char** argv)
{
int idx, c;
int awb = 1;
constexpr char shortOptions[] = "h:cwvaqof:";
c = getopt_long(argc, argv, shortOptions, longOptions, &idx);
while(1) {
switch (c) {
case 'h':
c = PutMenuAndGetChr(); // 打印菜单
break;
case 'f':
FlashLightTest(mainDemo); // 手电筒功能测试
c = PutMenuAndGetChr();
break;
case 'o':
OfflineTest(mainDemo); // Offline功能测试
c = PutMenuAndGetChr();
break;
case 'c':
CaptureTest(mainDemo); // Capture功能测试
c = PutMenuAndGetChr();
break;
case 'w': // AWB功能测试
if (awb) {
mainDemo->SetAwbMode(OHOS_CAMERA_AWB_MODE_INCANDESCENT);
} else {
mainDemo->SetAwbMode(OHOS_CAMERA_AWB_MODE_OFF);
}
awb = !awb;
c = PutMenuAndGetChr();
break;
case 'a': // AE功能测试
mainDemo->SetAeExpo();
c = PutMenuAndGetChr();
break;
case 'v': // Video功能测试
VideoTest(mainDemo);
c = PutMenuAndGetChr();
break;
case 'q': // 退出demo
PreviewOff(mainDemo);
mainDemo->QuitDemo();
exit(EXIT_SUCCESS);
default:
CAMERA_LOGE("main test: command error please retry input command");
c = PutMenuAndGetChr();
break;
}
}
}
```
PutMenuAndGetChr()接口打印了demo程序的菜单，并调用fgets()等待从控制台输入命令，内容如下：
```
static int PutMenuAndGetChr(void)
{
constexpr uint32_t inputCount = 50;
int c = 0;
char strs[inputCount];
Usage(stdout);
CAMERA_LOGD("pls input command(input -q exit this app)\n");
fgets(strs, inputCount, stdin);
for (int i = 0; i < inputCount; i++) {
if (strs[i] != '-') {
c = strs[i];
break;
}
}
return c;
}
```
控制台输出菜单详情如下：
```
"Options:\n"
"-h | --help Print this message\n"
"-o | --offline stream offline test\n"
"-c | --capture capture one picture\n"
"-w | --set WB Set white balance Cloudy\n"
"-v | --video capture Viedeo of 10s\n"
"-a | --Set AE Set Auto exposure\n"
"-f | --Set Flashlight Set flashlight ON 5s OFF\n"
"-q | --quit stop preview and quit this app\n");
```
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