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