使用相机预配置(C/C++)-开发相机应用基础能力(C/C++)-Camera Kit（相机服务）-媒体

相机预配置（Preconfig），对常用的场景和分辨率进行了预配置集成，可简化开发相机应用流程，提高应用的开发效率。

开发者在开发相机应用时，在获取到CameraDevice之后，如果遵循通用流程开发，步骤较为繁琐。需要先查询当前相机在指定模式下所支持的各类输出的配置信息，拿到Camera_OutputCapability之后，应用开发者还需要对里面的各类数据进行解析，筛选，找到自己需要的配置数据Camera_Profile和Camera_VideoProfile。最后使用对应的Profile以及VideoProfile创建对应的Camera_PreviewOutput、Camera_PhotoOutput以及Camera_VideoOutput。

为了解决上述问题，优化应用开发流程，系统针对拍照、录像两类场景（即Camera_SceneMode为NORMAL_PHOTO或NORMAL_VIDEO），提供了OH_CameraManager_CreatePreviewOutputUsedInPreconfig、OH_CameraManager_CreatePhotoOutputUsedInPreconfig、OH_CameraManager_CreateVideoOutputUsedInPreconfig接口帮助开发者快速完成相机参数配置。推荐仅需要自定义拍照界面的无需开发专业相机应用的开发者，使用相机预配置功能快速开发应用。

规格说明

系统提供了4种预配置类型（Camera_PreconfigType），分别为PRECONFIG_720P、PRECONFIG_1080P、PRECONFIG_4K、PRECONFIG_HIGH_QUALITY。以及3种画幅比例规格（Camera_PreconfigRatio），1:1画幅（PRECONFIG_RATIO_1_1）、4:3画幅（PRECONFIG_RATIO_4_3）、16:9画幅（PRECONFIG_RATIO_16_9）。

注意

由于不同的设备所支持的能力不同。使用相机预配置（preconfig）功能时，需要先调用OH_CaptureSession_CanPreconfig或OH_CaptureSession_CanPreconfigWithRatio检查对应的PreconfigType和PreconfigRatio的组合在当前设备上是否支持。

在不同的画幅比例下，其分辨率规格不同，详见下表。

普通拍照模式下的预览输出

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预配置类型PreconfigType	PRECONFIG_RATIO_1_1	PRECONFIG_RATIO_4_3	PRECONFIG_RATIO_16_9
PRECONFIG_720P	720x720	960x720	1280x720
PRECONFIG_1080P	1080x1080	1440x1080	1920x1080
PRECONFIG_4K	1080x1080	1440x1080	1920x1080
PRECONFIG_HIGH_QUALITY	1440x1440	1920x1440	2560x1440

普通拍照模式下的拍照输出

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预配置类型PreconfigType	PRECONFIG_RATIO_1_1	PRECONFIG_RATIO_4_3	PRECONFIG_RATIO_16_9
PRECONFIG_720P	720x720	960x720	1280x720
PRECONFIG_1080P	1080x1080	1440x1080	1920x1080
PRECONFIG_4K	2160x2160	2880x2160	3840x2160
PRECONFIG_HIGH_QUALITY	跟随Sensor最大能力	跟随Sensor最大能力	跟随Sensor最大能力

普通录像模式下的预览输出

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预配置类型PreconfigType	PRECONFIG_RATIO_1_1	PRECONFIG_RATIO_4_3	PRECONFIG_RATIO_16_9
PRECONFIG_720P	720x720	960x720	1280x720
PRECONFIG_1080P	1080x1080	1440x1080	1920x1080
PRECONFIG_4K	1080x1080	1440x1080	1920x1080
PRECONFIG_HIGH_QUALITY	1080x1080	1440x1080	1920x1080

普通录像模式下的录像输出

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预配置类型PreconfigType	PRECONFIG_RATIO_1_1	PRECONFIG_RATIO_4_3	PRECONFIG_RATIO_16_9
PRECONFIG_720P	720x720	960x720	1280x720
PRECONFIG_1080P	1080x1080	1440x1080	1920x1080
PRECONFIG_4K	2160x2160	2880x2160	3840x2160
PRECONFIG_HIGH_QUALITY	2160x2160	2880x2160	3840x2160

普通录像模式下的拍照输出

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预配置类型PreconfigType	PRECONFIG_RATIO_1_1	PRECONFIG_RATIO_4_3	PRECONFIG_RATIO_16_9
PRECONFIG_720P	跟随Sensor最大能力	跟随Sensor最大能力	跟随Sensor最大能力
PRECONFIG_1080P	跟随Sensor最大能力	跟随Sensor最大能力	跟随Sensor最大能力
PRECONFIG_4K	跟随Sensor最大能力	跟随Sensor最大能力	跟随Sensor最大能力
PRECONFIG_HIGH_QUALITY	跟随Sensor最大能力	跟随Sensor最大能力	跟随Sensor最大能力

开发示例

在CMake脚本中链接相关动态库。
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```
target_link_libraries(entry PUBLIC libohcamera.so libhilog_ndk.z.so)
```

cpp侧导入NDK接口，并根据传入的SurfaceId进行拍照。

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#include "hilog/log.h"
#include "ohcamera/camera.h"
#include "ohcamera/camera_input.h"
#include "ohcamera/capture_session.h"
#include "ohcamera/photo_output.h"
#include "ohcamera/preview_output.h"
#include "ohcamera/video_output.h"
#include "ohcamera/camera_manager.h"
class NDKCamera {
public:
    NDKCamera(char *previewId, char *photoId);
};

void CaptureSessionOnFocusStateChange(Camera_CaptureSession *session, Camera_FocusState focusState) {
    OH_LOG_INFO(LOG_APP, "CaptureSessionOnFocusStateChange");
}

void CaptureSessionOnError(Camera_CaptureSession *session, Camera_ErrorCode errorCode) {
    OH_LOG_INFO(LOG_APP, "CaptureSessionOnError = %{public}d", errorCode);
}

CaptureSession_Callbacks *GetCaptureSessionRegister(void) {
    static CaptureSession_Callbacks captureSessionCallbacks = {.onFocusStateChange = CaptureSessionOnFocusStateChange,
                                                               .onError = CaptureSessionOnError};
    return &captureSessionCallbacks;
}

void PreviewOutputOnFrameStart(Camera_PreviewOutput *previewOutput) {
    OH_LOG_INFO(LOG_APP, "PreviewOutputOnFrameStart");
}

void PreviewOutputOnFrameEnd(Camera_PreviewOutput *previewOutput, int32_t frameCount) {
    OH_LOG_INFO(LOG_APP, "PreviewOutputOnFrameEnd = %{public}d", frameCount);
}

void PreviewOutputOnError(Camera_PreviewOutput *previewOutput, Camera_ErrorCode errorCode) {
    OH_LOG_INFO(LOG_APP, "PreviewOutputOnError = %{public}d", errorCode);
}

PreviewOutput_Callbacks *GetPreviewOutputListener(void) {
    static PreviewOutput_Callbacks previewOutputListener = {.onFrameStart = PreviewOutputOnFrameStart,
                                                            .onFrameEnd = PreviewOutputOnFrameEnd,
                                                            .onError = PreviewOutputOnError};
    return &previewOutputListener;
}

void OnCameraInputError(const Camera_Input *cameraInput, Camera_ErrorCode errorCode) {
    OH_LOG_INFO(LOG_APP, "OnCameraInput errorCode = %{public}d", errorCode);
}

CameraInput_Callbacks *GetCameraInputListener(void) {
    static CameraInput_Callbacks cameraInputCallbacks = {.onError = OnCameraInputError};
    return &cameraInputCallbacks;
}

void CameraManagerStatusCallback(Camera_Manager *cameraManager, Camera_StatusInfo *status) {
    OH_LOG_INFO(LOG_APP, "CameraManagerStatusCallback is called");
}

CameraManager_Callbacks *GetCameraManagerListener() {
    static CameraManager_Callbacks cameraManagerListener = {.onCameraStatus = CameraManagerStatusCallback};
    return &cameraManagerListener;
}

NDKCamera::NDKCamera(char *previewId, char *photoId) {
    Camera_Manager *cameraManager = nullptr;
    Camera_Device *cameras = nullptr;
    Camera_CaptureSession *captureSession = nullptr;
    Camera_PreviewOutput *previewOutput = nullptr;
    Camera_PhotoOutput *photoOutput = nullptr;
    Camera_Input *cameraInput = nullptr;
    uint32_t size = 0;
    uint32_t cameraDeviceIndex = 0;
    char *previewSurfaceId = previewId;
    char *photoSurfaceId = photoId;
    // 创建CameraManager对象
    Camera_ErrorCode ret = OH_Camera_GetCameraManager(&cameraManager);
    if (cameraManager == nullptr || ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_Camera_GetCameraMananger failed.");
    }
    // 监听相机状态变化
    ret = OH_CameraManager_RegisterCallback(cameraManager, GetCameraManagerListener());
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CameraManager_RegisterCallback failed.");
    }

    // 获取相机列表
    ret = OH_CameraManager_GetSupportedCameras(cameraManager, &cameras, &size);
    if (cameras == nullptr || size < 0 || ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CameraManager_GetSupportedCameras failed.");
    }

    // 创建相机输入流
    ret = OH_CameraManager_CreateCameraInput(cameraManager, &cameras[cameraDeviceIndex], &cameraInput);
    if (cameraInput == nullptr || ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreateCameraInput failed.");
    }

    // 监听cameraInput错误信息
    ret = OH_CameraInput_RegisterCallback(cameraInput, GetCameraInputListener());
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CameraInput_RegisterCallback failed.");
    }

    // 打开相机
    ret = OH_CameraInput_Open(cameraInput);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CameraInput_Open failed.");
    }

    // 创建会话
    ret = OH_CameraManager_CreateCaptureSession(cameraManager, &captureSession);
    if (captureSession == nullptr || ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreateCaptureSession failed.");
    }

    // 监听session错误信息
    ret = OH_CaptureSession_RegisterCallback(captureSession, GetCaptureSessionRegister());
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_RegisterCallback failed.");
    }

    // 查询Preconfig能力
    bool canPreconfigResult = false;
    ret = OH_CaptureSession_CanPreconfig(captureSession, PRECONFIG_1080P, &canPreconfigResult);
    if (ret != CAMERA_OK || !canPreconfigResult) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_CanPreconfig failed.");
    }

    // 配置Preconfig
    ret = OH_CaptureSession_Preconfig(captureSession, PRECONFIG_1080P);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_Preconfig failed.");
    }

    // 创建预览输出流,其中参数 previewSurfaceId 参考上文 XComponent 组件，预览流为XComponent组件提供的surface
    ret = OH_CameraManager_CreatePreviewOutputUsedInPreconfig(cameraManager, previewSurfaceId, &previewOutput);
    if (previewOutput == nullptr || ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreatePreviewOutput failed.");
    }

    // 监听预览输出错误信息
    ret = OH_PreviewOutput_RegisterCallback(previewOutput, GetPreviewOutputListener());
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_PreviewOutput_RegisterCallback failed.");
    }

    // 创建拍照输出流，其中参数 photoSurfaceId 参考上文 ImageReceiver获取的surface
    ret = OH_CameraManager_CreatePhotoOutputUsedInPreconfig(cameraManager, photoSurfaceId, &photoOutput);
    if (photoOutput == nullptr || ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CameraManager_CreatePhotoOutput failed.");
    }

    // 开始配置会话
    ret = OH_CaptureSession_BeginConfig(captureSession);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_BeginConfig failed.");
    }

    // 向会话中添加相机输入流
    ret = OH_CaptureSession_AddInput(captureSession, cameraInput);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_AddInput failed.");
    }

    // 向会话中添加预览输出流
    ret = OH_CaptureSession_AddPreviewOutput(captureSession, previewOutput);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_AddPreviewOutput failed.");
    }

    // 向会话中添加拍照输出流
    ret = OH_CaptureSession_AddPhotoOutput(captureSession, photoOutput);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_AddPhotoOutput failed.");
    }

    // 提交会话配置
    ret = OH_CaptureSession_CommitConfig(captureSession);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_CommitConfig failed.");
    }

    // 启动会话
    ret = OH_CaptureSession_Start(captureSession);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_Start failed.");
    }

    // 判断设备是否支持闪光灯
    Camera_FlashMode flashMode = FLASH_MODE_AUTO;
    bool hasFlash = false;
    ret = OH_CaptureSession_HasFlash(captureSession, &hasFlash);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_HasFlash failed.");
    }
    if (hasFlash) {
        OH_LOG_INFO(LOG_APP, "hasFlash success");
    } else {
        OH_LOG_ERROR(LOG_APP, "hasFlash fail");
    }
    // 检测闪光灯模式是否支持
    bool isSupported = false;
    ret = OH_CaptureSession_IsFlashModeSupported(captureSession, flashMode, &isSupported);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_IsFlashModeSupported failed.");
    }
    if (isSupported) {
        OH_LOG_INFO(LOG_APP, "isFlashModeSupported success");
        // 设置闪光灯模式
        ret = OH_CaptureSession_SetFlashMode(captureSession, flashMode);
        if (ret == CAMERA_OK) {
            OH_LOG_INFO(LOG_APP, "OH_CaptureSession_SetFlashMode success.");
        } else {
            OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_SetFlashMode failed. %{public}d ", ret);
        }
        // 获取当前设备的闪光灯模式
        ret = OH_CaptureSession_GetFlashMode(captureSession, &flashMode);
        if (ret == CAMERA_OK) {
            OH_LOG_INFO(LOG_APP, "OH_CaptureSession_GetFlashMode success. flashMode：%{public}d ", flashMode);
        } else {
            OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_GetFlashMode failed. %d ", ret);
        }
    } else {
        OH_LOG_ERROR(LOG_APP, "isFlashModeSupported fail");
    }

    // 判断是否支持连续自动变焦模式
    Camera_FocusMode focusMode = FOCUS_MODE_CONTINUOUS_AUTO;
    bool isFocusModeSupported = false;
    ret = OH_CaptureSession_IsFocusModeSupported(captureSession, focusMode, &isFocusModeSupported);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_IsFocusModeSupported failed.");
    }
    if (isFocusModeSupported) {
        OH_LOG_INFO(LOG_APP, "isFocusModeSupported success");
        ret = OH_CaptureSession_SetFocusMode(captureSession, focusMode);
        if (ret != CAMERA_OK) {
            OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_SetFocusMode failed. %{public}d ", ret);
        }
        ret = OH_CaptureSession_GetFocusMode(captureSession, &focusMode);
        if (ret == CAMERA_OK) {
            OH_LOG_INFO(LOG_APP, "OH_CaptureSession_GetFocusMode success. focusMode%{public}d ", focusMode);
        } else {
            OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_GetFocusMode failed. %d ", ret);
        }
    } else {
        OH_LOG_ERROR(LOG_APP, "isFocusModeSupported fail");
    }

    // 获取相机支持的可变焦距比范围
    float minZoom;
    float maxZoom;
    ret = OH_CaptureSession_GetZoomRatioRange(captureSession, &minZoom, &maxZoom);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_GetZoomRatioRange failed.");
    } else {
        OH_LOG_INFO(LOG_APP, "OH_CaptureSession_GetZoomRatioRange success. minZoom: %{public}f, maxZoom:%{public}f",
                    minZoom, maxZoom);
    }
    // 设置变焦
    ret = OH_CaptureSession_SetZoomRatio(captureSession, maxZoom);
    if (ret == CAMERA_OK) {
        OH_LOG_INFO(LOG_APP, "OH_CaptureSession_SetZoomRatio success.");
    } else {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_SetZoomRatio failed. %{public}d ", ret);
    }
    // 获取当前设备的变焦值
    ret = OH_CaptureSession_GetZoomRatio(captureSession, &maxZoom);
    if (ret == CAMERA_OK) {
        OH_LOG_INFO(LOG_APP, "OH_CaptureSession_GetZoomRatio success. zoom：%{public}f ", maxZoom);
    } else {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_GetZoomRatio failed. %{public}d ", ret);
    }

    // 无拍照设置进行拍照
    ret = OH_PhotoOutput_Capture(photoOutput);
    if (ret == CAMERA_OK) {
        OH_LOG_INFO(LOG_APP, "OH_PhotoOutput_Capture success ");
    } else {
        OH_LOG_ERROR(LOG_APP, "OH_PhotoOutput_Capture failed. %d ", ret);
    }

    // 停止当前会话
    ret = OH_CaptureSession_Stop(captureSession);
    if (ret == CAMERA_OK) {
        OH_LOG_INFO(LOG_APP, "OH_CaptureSession_Stop success ");
    } else {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_Stop failed. %d ", ret);
    }

    // 释放相机输入流
    ret = OH_CameraInput_Close(cameraInput);
    if (ret == CAMERA_OK) {
        OH_LOG_INFO(LOG_APP, "OH_CameraInput_Close success ");
    } else {
        OH_LOG_ERROR(LOG_APP, "OH_CameraInput_Close failed. %d ", ret);
    }

    // 释放预览输出流
    ret = OH_PreviewOutput_Release(previewOutput);
    if (ret == CAMERA_OK) {
        OH_LOG_INFO(LOG_APP, "OH_PreviewOutput_Release success ");
    } else {
        OH_LOG_ERROR(LOG_APP, "OH_PreviewOutput_Release failed. %d ", ret);
    }

    // 释放拍照输出流
    ret = OH_PhotoOutput_Release(photoOutput);
    if (ret == CAMERA_OK) {
        OH_LOG_INFO(LOG_APP, "OH_PhotoOutput_Release success ");
    } else {
        OH_LOG_ERROR(LOG_APP, "OH_PhotoOutput_Release failed. %d ", ret);
    }

    // 释放会话
    ret = OH_CaptureSession_Release(captureSession);
    if (ret == CAMERA_OK) {
        OH_LOG_INFO(LOG_APP, "OH_CaptureSession_Release success ");
    } else {
        OH_LOG_ERROR(LOG_APP, "OH_CaptureSession_Release failed. %d ", ret);
    }

    // 资源释放
    ret = OH_CameraManager_DeleteSupportedCameras(cameraManager, cameras, size);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "Delete Cameras failed.");
    } else {
        OH_LOG_INFO(LOG_APP, "OH_CameraManager_DeleteSupportedCameras. ok");
    }

    ret = OH_Camera_DeleteCameraManager(cameraManager);
    if (ret != CAMERA_OK) {
        OH_LOG_ERROR(LOG_APP, "Delete Cameras failed.");
    } else {
        OH_LOG_INFO(LOG_APP, "OH_Camera_DeleteCameraManager. ok");
    }
}