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1# 设备输入(C/C++)
2<!--Kit: Camera Kit-->
3<!--Subsystem: Multimedia-->
4<!--Owner: @qano-->
5<!--Designer: @leo_ysl-->
6<!--Tester: @xchaosioda-->
7<!--Adviser: @zengyawen-->
8
9在开发相机应用时，需要先[申请相关权限](camera-preparation.md)。
10
11相机应用通过调用和控制相机设备，完成预览、拍照和录像等基础操作。
12
13## 开发步骤
14
15详细的API说明请参考[Camera API参考](../../reference/apis-camera-kit/capi-oh-camera.md)。
16
171. 导入NDK接口。选择系统提供的NDK接口能力，导入NDK接口的方法如下。
18
19   ```c++
20   // 导入NDK接口头文件。
21   #include "hilog/log.h"
22   #include "ohcamera/camera.h"
23   #include "ohcamera/camera_input.h"
24   #include "ohcamera/capture_session.h"
25   #include "ohcamera/photo_output.h"
26   #include "ohcamera/preview_output.h"
27   #include "ohcamera/video_output.h"
28   #include "ohcamera/camera_manager.h"
29   ```
30
312. 在CMake脚本中链接相关动态库。
32
33   ```txt
34   target_link_libraries(entry PUBLIC
35       libace_napi.z.so
36       libohcamera.so
37       libhilog_ndk.z.so
38   )
39   ```
40
413. 通过[OH_CameraManager_CreateCameraInput()](../../reference/apis-camera-kit/capi-camera-manager-h.md#oh_cameramanager_createcamerainput)方法，获取cameraInput对象。
42   ```c++
43   // 监听cameraInput错误信息。
44   void OnCameraInputError(const Camera_Input* cameraInput, Camera_ErrorCode errorCode)
45   {
46      OH_LOG_INFO(LOG_APP, "OnCameraInput errorCode: %{public}d", errorCode);
47   }
48
49   CameraInput_Callbacks* GetCameraInputListener(void)
50   {
51      static CameraInput_Callbacks cameraInputCallbacks = {
52         .onError = OnCameraInputError
53      };
54      return &cameraInputCallbacks;
55   }
56   ```
57   ```c++
58   // 监听cameraStatus信息。
59   void CameraManagerStatusCallback(Camera_Manager* cameraManager, Camera_StatusInfo* status)
60   {
61       OH_LOG_INFO(LOG_APP, "CameraManagerStatusCallback is called");
62   }
63
64   CameraManager_Callbacks* GetCameraManagerListener()
65   {
66       static CameraManager_Callbacks cameraManagerListener = {
67           .onCameraStatus = CameraManagerStatusCallback
68       };
69       return &cameraManagerListener;
70   }
71   ```
72   ```c++
73   void CreateAndOpenCamera()
74   {
75       Camera_Manager* cameraManager = nullptr;
76       Camera_Input* cameraInput = nullptr;
77       Camera_Device* cameras = nullptr;
78       uint32_t size = 0;
79       uint32_t cameraDeviceIndex = 0;
80       // 创建CameraManager对象。
81       Camera_ErrorCode ret = OH_Camera_GetCameraManager(&cameraManager);
82       if (cameraManager == nullptr || ret != CAMERA_OK) {
83           OH_LOG_ERROR(LOG_APP, "OH_Camera_GetCameraManager failed.");
84           return;
85       }
86       // 监听相机状态变化。
87       ret = OH_CameraManager_RegisterCallback(cameraManager, GetCameraManagerListener());
88       if (ret != CAMERA_OK) {
89           OH_LOG_ERROR(LOG_APP, "OH_CameraManager_RegisterCallback failed.");
90       }
91       // 获取相机列表。
92        ret = OH_CameraManager_GetSupportedCameras(cameraManager, &cameras, &size);
93        if (cameras == nullptr || size < 0 || ret != CAMERA_OK) {
94            OH_LOG_ERROR(LOG_APP, "OH_CameraManager_GetSupportedCameras failed.");
95            return;
96        }
97       // 创建相机输入流。
98       ret = OH_CameraManager_CreateCameraInput(cameraManager, &cameras[cameraDeviceIndex], &cameraInput);
99       if (cameraInput == nullptr || ret != CAMERA_OK) {
100           OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreateCameraInput failed.");
101           return;
102       }
103       ret = OH_CameraInput_RegisterCallback(cameraInput, GetCameraInputListener());
104       if (ret != CAMERA_OK) {
105           OH_LOG_ERROR(LOG_APP, "OH_CameraInput_RegisterCallback failed.");
106       }
107       // 打开相机。
108       ret = OH_CameraInput_Open(cameraInput);
109       if (ret != CAMERA_OK) {
110           OH_LOG_ERROR(LOG_APP, "OH_CameraInput_open failed.");
111           return;
112       }
113   }
114   ```
115
116   > **说明：**
117   >
118   > 在相机设备输入之前需要先完成相机管理，详细开发步骤请参考[相机管理](native-camera-device-management.md)。
119
1204. 通过[OH_CameraManager_GetSupportedSceneModes()](../../reference/apis-camera-kit/capi-camera-manager-h.md#oh_cameramanager_getsupportedscenemodes)方法，获取当前相机设备支持的模式列表，列表中存储了相机设备支持的所有模式[Camera_SceneMode](../../reference/apis-camera-kit/capi-camera-h.md#camera_scenemode)。
121
122   ```c++
123   bool IsSupportedSceneMode(Camera_Device camera, Camera_SceneMode sceneMode)
124   {
125       Camera_SceneMode* sceneModes = nullptr;
126       uint32_t sceneModeSize = 0;
127       Camera_ErrorCode ret = OH_CameraManager_GetSupportedSceneModes(&camera, &sceneModes, &sceneModeSize);
128       if (sceneModes == nullptr || ret != CAMERA_OK) {
129           OH_LOG_ERROR(LOG_APP, "OH_CameraManager_GetSupportedSceneModes failed.");
130           return false;
131       }
132       for (int index = 0; index < sceneModeSize; index++) {
133           OH_LOG_INFO(LOG_APP, "scene mode = %{public}u ", sceneModes[index]);    // 获取相机指定模式。
134           if (sceneModes[index] == sceneMode) {
135               return true;
136           }
137       }
138       return false;
139   }
140   ```
141
1425. 通过[OH_CameraManager_GetSupportedCameraOutputCapabilityWithSceneMode()](../../reference/apis-camera-kit/capi-camera-manager-h.md#oh_cameramanager_getsupportedcameraoutputcapabilitywithscenemode)方法，获取当前设备支持的所有输出流，如预览流、拍照流等。输出流在CameraOutputCapability中的各个profile字段中。根据相机设备指定模式[Camera_SceneMode](../../reference/apis-camera-kit/capi-camera-h.md#camera_scenemode)的不同，需要添加不同类型的输出流。
143
144
145   ```c++
146   Camera_OutputCapability* GetSupportedCameraOutputCapability(Camera_Manager* cameraManager, Camera_Device &camera)
147   {
148       Camera_OutputCapability* cameraOutputCapability = nullptr;
149       // 示例代码以NORMAL_PHOTO模式为例，查询NORMAL_PHOTO在camera中是否支持。
150       bool isSupported = IsSupportedSceneMode(camera, Camera_SceneMode::NORMAL_PHOTO);
151       if (!isSupported) {
152           OH_LOG_ERROR(LOG_APP, "NORMAL_PHOTO is not supported.");
153           return cameraOutputCapability;
154       }
155       // 获取相机设备支持的输出流能力。
156       const Camera_Profile* previewProfile = nullptr;
157       const Camera_Profile* photoProfile = nullptr;
158       Camera_ErrorCode ret = OH_CameraManager_GetSupportedCameraOutputCapabilityWithSceneMode(cameraManager, &camera,
159           Camera_SceneMode::NORMAL_PHOTO, &cameraOutputCapability);
160       if (cameraOutputCapability == nullptr || ret != CAMERA_OK) {
161           OH_LOG_ERROR(LOG_APP, "OH_CameraManager_GetSupportedCameraOutputCapability failed.");
162           return cameraOutputCapability;
163       }
164       // 以NORMAL_PHOTO模式为例，需要添加预览流、拍照流。
165       if (cameraOutputCapability->previewProfiles == nullptr) {
166           OH_LOG_ERROR(LOG_APP, "previewProfiles == null");
167       } else {
168           // 根据所需从cameraOutputCapability->previewProfiles中选择合适的预览分辨率。
169           previewProfile = cameraOutputCapability->previewProfiles[0];
170       }
171       if (cameraOutputCapability->photoProfiles == nullptr) {
172           OH_LOG_ERROR(LOG_APP, "photoProfiles == null");
173       } else {
174           // 根据所需从cameraOutputCapability->photoProfiles中选择合适的拍照分辨率。
175           photoProfile = cameraOutputCapability->photoProfiles[0];
176       }
177       return cameraOutputCapability;
178   }
179   ```