1# Sample of Secondary Processing of Video Streams (C/C++) 2 3## Development Process 4 5Before developing a camera application, request the camera permission. For details, see [Camera Development Preparations](camera-preparation.md). 6 7After obtaining the output stream capabilities supported by the camera, create a video stream. The development process is as follows: 8 9 10 11## Sample Code 12 131. Link the dynamic library in the CMake script. 14 ```txt 15 target_link_libraries(entry PUBLIC libohcamera.so libhilog_ndk.z.so) 16 ``` 17 182. Import the NDK APIs on the C++ side, and perform video recording based on the surface ID passed in. 19 ```c++ 20 #include "hilog/log.h" 21 #include "ohcamera/camera.h" 22 #include "ohcamera/camera_input.h" 23 #include "ohcamera/capture_session.h" 24 #include "ohcamera/photo_output.h" 25 #include "ohcamera/preview_output.h" 26 #include "ohcamera/video_output.h" 27 #include "ohcamera/camera_manager.h" 28 29 void OnCameraInputError(const Camera_Input* cameraInput, Camera_ErrorCode errorCode) 30 { 31 OH_LOG_INFO(LOG_APP, "OnCameraInput errorCode = %{public}d", errorCode); 32 } 33 34 CameraInput_Callbacks* GetCameraInputListener(void) 35 { 36 static CameraInput_Callbacks cameraInputCallbacks = { 37 .onError = OnCameraInputError 38 }; 39 return &cameraInputCallbacks; 40 } 41 42 void CaptureSessionOnFocusStateChange(Camera_CaptureSession* session, Camera_FocusState focusState) 43 { 44 OH_LOG_INFO(LOG_APP, "CaptureSessionOnFocusStateChange"); 45 } 46 47 void CaptureSessionOnError(Camera_CaptureSession* session, Camera_ErrorCode errorCode) 48 { 49 OH_LOG_INFO(LOG_APP, "CaptureSessionOnError = %{public}d", errorCode); 50 } 51 52 CaptureSession_Callbacks* GetCaptureSessionRegister(void) 53 { 54 static CaptureSession_Callbacks captureSessionCallbacks = { 55 .onFocusStateChange = CaptureSessionOnFocusStateChange, 56 .onError = CaptureSessionOnError 57 }; 58 return &captureSessionCallbacks; 59 } 60 61 void VideoOutputOnFrameStart(Camera_VideoOutput* videoOutput) 62 { 63 OH_LOG_INFO(LOG_APP, "VideoOutputOnFrameStart"); 64 } 65 66 void VideoOutputOnFrameEnd(Camera_VideoOutput* videoOutput, int32_t frameCount) 67 { 68 OH_LOG_INFO(LOG_APP, "VideoOutput frameCount = %{public}d", frameCount); 69 } 70 71 void VideoOutputOnError(Camera_VideoOutput* videoOutput, Camera_ErrorCode errorCode) 72 { 73 OH_LOG_INFO(LOG_APP, "VideoOutput errorCode = %{public}d", errorCode); 74 } 75 76 VideoOutput_Callbacks* GetVideoOutputListener(void) 77 { 78 static VideoOutput_Callbacks videoOutputListener = { 79 .onFrameStart = VideoOutputOnFrameStart, 80 .onFrameEnd = VideoOutputOnFrameEnd, 81 .onError = VideoOutputOnError 82 }; 83 return &videoOutputListener; 84 } 85 86 void CameraManagerStatusCallback(Camera_Manager* cameraManager, Camera_StatusInfo* status) 87 { 88 OH_LOG_INFO(LOG_APP, "CameraManagerStatusCallback is called"); 89 } 90 91 CameraManager_Callbacks* GetCameraManagerListener() 92 { 93 static CameraManager_Callbacks cameraManagerListener = { 94 .onCameraStatus = CameraManagerStatusCallback 95 }; 96 return &cameraManagerListener; 97 } 98 99 NDKCamera::NDKCamera(char *previewId, char *videoId) 100 { 101 Camera_Manager* cameraManager = nullptr; 102 Camera_Device* cameras = nullptr; 103 Camera_CaptureSession* captureSession = nullptr; 104 Camera_OutputCapability* cameraOutputCapability = nullptr; 105 Camera_VideoOutput* videoOutput = nullptr; 106 const Camera_Profile* previewProfile = nullptr; 107 const Camera_Profile* photoProfile = nullptr; 108 const Camera_VideoProfile* videoProfile = nullptr; 109 Camera_PreviewOutput* previewOutput = nullptr; 110 Camera_PhotoOutput* photoOutput = nullptr; 111 Camera_Input* cameraInput = nullptr; 112 uint32_t size = 0; 113 uint32_t cameraDeviceIndex = 0; 114 char* videoSurfaceId = videoId; 115 char* previewSurfaceId = previewId; 116 // Create a CameraManager object. 117 Camera_ErrorCode ret = OH_Camera_GetCameraManager(&cameraManager); 118 if (cameraManager == nullptr || ret != CAMERA_OK) { 119 OH_LOG_ERROR(LOG_APP, "OH_Camera_GetCameraMananger failed."); 120 } 121 // Listen for camera status changes. 122 ret = OH_CameraManager_RegisterCallback(cameraManager, GetCameraManagerListener()); 123 if (ret != CAMERA_OK) { 124 OH_LOG_ERROR(LOG_APP, "OH_CameraManager_RegisterCallback failed."); 125 } 126 127 // Obtain the camera list. 128 ret = OH_CameraManager_GetSupportedCameras(cameraManager, &cameras, &size); 129 if (cameras == nullptr || size < 0 || ret != CAMERA_OK) { 130 OH_LOG_ERROR(LOG_APP, "OH_CameraManager_GetSupportedCameras failed."); 131 } 132 133 for (int index = 0; index < size; index++) { 134 OH_LOG_ERROR(LOG_APP, "cameraId = %{public}s ", cameras[index].cameraId); // Obtain the camera ID. 135 OH_LOG_ERROR(LOG_APP, "cameraPosition = %{public}d ", cameras[index].cameraPosition); // Obtain the camera position. 136 OH_LOG_ERROR(LOG_APP, "cameraType = %{public}d ", cameras[index].cameraType); // Obtain the camera type. 137 OH_LOG_ERROR(LOG_APP, "connectionType = %{public}d ", cameras[index].connectionType); // Obtain the camera connection type. 138 } 139 140 // Obtain the output streams supported by the camera. 141 ret = OH_CameraManager_GetSupportedCameraOutputCapability(cameraManager, &cameras[cameraDeviceIndex], 142 &cameraOutputCapability); 143 if (cameraOutputCapability == nullptr || ret != CAMERA_OK) { 144 OH_LOG_ERROR(LOG_APP, "OH_CameraManager_GetSupportedCameraOutputCapability failed."); 145 } 146 147 if (cameraOutputCapability->previewProfilesSize < 0) { 148 OH_LOG_ERROR(LOG_APP, "previewProfilesSize == null"); 149 } 150 previewProfile = cameraOutputCapability->previewProfiles[0]; 151 152 if (cameraOutputCapability->photoProfilesSize < 0) { 153 OH_LOG_ERROR(LOG_APP, "photoProfilesSize == null"); 154 } 155 photoProfile = cameraOutputCapability->photoProfiles[0]; 156 157 if (cameraOutputCapability->videoProfilesSize < 0) { 158 OH_LOG_ERROR(LOG_APP, "videorofilesSize == null"); 159 } 160 videoProfile = cameraOutputCapability->videoProfiles[0]; 161 162 // Call getVideoSurfaceID() on the TS side. 163 164 // Create a VideoOutput instance. 165 ret = OH_CameraManager_CreateVideoOutput(cameraManager, videoProfile, videoSurfaceId, &videoOutput); 166 if (videoProfile == nullptr || videoOutput == nullptr || ret != CAMERA_OK) { 167 OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreateVideoOutput failed."); 168 } 169 170 // Listen for video output errors. 171 ret = OH_VideoOutput_RegisterCallback(videoOutput, GetVideoOutputListener()); 172 if (ret != CAMERA_OK) { 173 OH_LOG_ERROR(LOG_APP, "OH_VideoOutput_RegisterCallback failed."); 174 } 175 176 // Create a session. 177 ret = OH_CameraManager_CreateCaptureSession(cameraManager, &captureSession); 178 if (captureSession == nullptr || ret != CAMERA_OK) { 179 OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreateCaptureSession failed."); 180 } 181 // Listen for session errors. 182 ret = OH_CaptureSession_RegisterCallback(captureSession, GetCaptureSessionRegister()); 183 if (ret != CAMERA_OK) { 184 OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_RegisterCallback failed."); 185 } 186 187 // Start configuration for the session. 188 ret = OH_CaptureSession_BeginConfig(captureSession); 189 if (ret != CAMERA_OK) { 190 OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_BeginConfig failed."); 191 } 192 193 // Create a camera input stream. 194 ret = OH_CameraManager_CreateCameraInput(cameraManager, &cameras[cameraDeviceIndex], &cameraInput); 195 if (cameraInput == nullptr || ret != CAMERA_OK) { 196 OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreateCameraInput failed."); 197 } 198 199 // Listen for camera input errors. 200 ret = OH_CameraInput_RegisterCallback(cameraInput, GetCameraInputListener()); 201 if (ret != CAMERA_OK) { 202 OH_LOG_ERROR(LOG_APP, "OH_CameraInput_RegisterCallback failed."); 203 } 204 205 // Open the camera. 206 ret = OH_CameraInput_Open(cameraInput); 207 if (ret != CAMERA_OK) { 208 OH_LOG_ERROR(LOG_APP, "OH_CameraInput_Open failed."); 209 } 210 211 // Add the camera input stream to the session. 212 ret = OH_CaptureSession_AddInput(captureSession, cameraInput); 213 if (ret != CAMERA_OK) { 214 OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_AddInput failed."); 215 } 216 217 // Create a preview output stream. For details about the surfaceId parameter, see the XComponent. The preview stream is the surface provided by the XComponent. 218 ret = OH_CameraManager_CreatePreviewOutput(cameraManager, previewProfile, previewSurfaceId, &previewOutput); 219 if (previewProfile == nullptr || previewOutput == nullptr || ret != CAMERA_OK) { 220 OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreatePreviewOutput failed."); 221 } 222 223 // Add the preview output stream to the session. 224 ret = OH_CaptureSession_AddPreviewOutput(captureSession, previewOutput); 225 if (ret != CAMERA_OK) { 226 OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_AddPreviewOutput failed."); 227 } 228 229 // Add the video output stream to the session. 230 ret = OH_CaptureSession_AddVideoOutput(captureSession, videoOutput); 231 if (ret != CAMERA_OK) { 232 OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_AddVideoOutput failed."); 233 } 234 235 // Commit the session configuration. 236 ret = OH_CaptureSession_CommitConfig(captureSession); 237 if (ret != CAMERA_OK) { 238 OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_CommitConfig failed."); 239 } 240 241 // Start the session. 242 ret = OH_CaptureSession_Start(captureSession); 243 if (ret != CAMERA_OK) { 244 OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_Start failed."); 245 } 246 247 // Start the video output stream. 248 ret = OH_VideoOutput_Start(videoOutput); 249 if (ret != CAMERA_OK) { 250 OH_LOG_ERROR(LOG_APP, "OH_VideoOutput_Start failed."); 251 } 252 253 // Stop the video output stream. 254 ret = OH_VideoOutput_Stop(videoOutput); 255 if (ret != CAMERA_OK) { 256 OH_LOG_ERROR(LOG_APP, "OH_VideoOutput_Stop failed."); 257 } 258 259 // Stop the session. 260 ret = OH_CaptureSession_Stop(captureSession); 261 if (ret == CAMERA_OK) { 262 OH_LOG_INFO(LOG_APP, "OH_CaptureSession_Stop success "); 263 } else { 264 OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_Stop failed. %d ", ret); 265 } 266 267 // Release the camera input stream. 268 ret = OH_CameraInput_Close(cameraInput); 269 if (ret == CAMERA_OK) { 270 OH_LOG_INFO(LOG_APP, "OH_CameraInput_Close success "); 271 } else { 272 OH_LOG_ERROR(LOG_APP, "OH_CameraInput_Close failed. %d ", ret); 273 } 274 275 // Release the preview output stream. 276 ret = OH_PreviewOutput_Release(previewOutput); 277 if (ret == CAMERA_OK) { 278 OH_LOG_INFO(LOG_APP, "OH_PreviewOutput_Release success "); 279 } else { 280 OH_LOG_ERROR(LOG_APP, "OH_PreviewOutput_Release failed. %d ", ret); 281 } 282 283 // Release the video output stream. 284 ret = OH_VideoOutput_Release(videoOutput); 285 if (ret == CAMERA_OK) { 286 OH_LOG_INFO(LOG_APP, "OH_VideoOutput_Release success "); 287 } else { 288 OH_LOG_ERROR(LOG_APP, "OH_VideoOutput_Release failed. %d ", ret); 289 } 290 291 // Release the session. 292 ret = OH_CaptureSession_Release(captureSession); 293 if (ret == CAMERA_OK) { 294 OH_LOG_INFO(LOG_APP, "OH_CaptureSession_Release success "); 295 } else { 296 OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_Release failed. %d ", ret); 297 } 298 } 299 ``` 300
