HarmonyOS鸿蒙Next中相机实时预览及对预览流数据实时处理

自定义相机可以参考官方文档：https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/camera-dev-arkts-V5

onImageArrival()中就是双路预览拿到帧数据的地方，这里面就可以把pixelmap数据用来ai处理。

可以参考下面的代码：

import { camera } from '@kit.CameraKit'
import { BusinessError } from '@kit.BasicServicesKit'
import { image } from '@kit.ImageKit'
import { buffer } from '@kit.ArkTS'
import { photoAccessHelper } from '@kit.MediaLibraryKit'
import { abilityAccessCtrl, PermissionRequestResult, Permissions } from '@kit.AbilityKit'
import { display, promptAction } from '@kit.ArkUI'
import { fileIo } from '@kit.CoreFileKit'
import fs from '@ohos.file.fs'
const TAG = '[CameraDemo]'
@Entry
@Component
struct CameraDemo {
  context: Context = getContext(this) as Context;
  @State pixelMap: image.PixelMap | undefined = undefined;
  @State finalPixelMap: image.PixelMap | undefined = undefined;
  @State buffer: ArrayBuffer | undefined = undefined;
  @State surfaceId: string = '';
  @State hasPicture: boolean = false;
  @State fileNames: string[] = [];
  @State imageSize: image.Size = { width: 1920, height: 1080 };
  @State saveButtonOptions: SaveButtonOptions = {
    icon: SaveIconStyle.FULL_FILLED,
    text: SaveDescription.SAVE_IMAGE,
    buttonType: ButtonType.Capsule
  } // 设置安全控件按钮属性
  private mXComponentController: XComponentController = new XComponentController;
  private cameraManager: camera.CameraManager | undefined = undefined;
  private cameraSession: camera.PhotoSession | undefined = undefined;
  private photoOutput: camera.PhotoOutput | undefined = undefined;
  private cameraInput: camera.CameraInput | undefined = undefined;
  private previewOutput: camera.PreviewOutput | undefined = undefined;
  private previewOutput2: camera.PreviewOutput | undefined = undefined;
  private imageReceiver: image.ImageReceiver | undefined = undefined;
  @State ca: number  = 0
  @State screenWidth: number  = 0
  @State screenHeight: number  = 0
  @State base64Str: string  = ''

  aboutToAppear(): void {
    let permissions: Array<Permissions> = [
      'ohos.permission.CAMERA',
      'ohos.permission.WRITE_MEDIA',
      'ohos.permission.READ_MEDIA',
      'ohos.permission.MEDIA_LOCATION',
    ];
    let atManager: abilityAccessCtrl.AtManager = abilityAccessCtrl.createAtManager();
    atManager.requestPermissionsFromUser(this.context, permissions).then((data: PermissionRequestResult) => {
      let grantStatus: Array<number> = data.authResults;
      let length: number = grantStatus.length;
      for (let i = 0; i < length; i++) {
        if (grantStatus[i] != 0) {
          return;
        }
      }
      console.info(`${TAG} Success to request permissions from user. authResults is ${grantStatus}.`);
    }).catch((err: BusinessError) => {
      console.error(`${TAG} Failed to request permissions from user. Code is ${err.code}, message is ${err.message}`);
    })
    let displaydef = display.getDefaultDisplaySync()
    this.screenWidth = displaydef.width
    this.screenHeight = displaydef.height
  }

  createCameraManager() {
    // 创建CameraManager对象
    let cameraManager: camera.CameraManager = camera.getCameraManager(this.context);
    if (!cameraManager) {
      console.error('CameraDemo camera.getCameraManager error')
      return;
    }
    this.cameraManager = cameraManager;

    // 监听相机状态变化
    this.cameraManager.on('cameraStatus', (err: BusinessError, cameraStatusInfo: camera.CameraStatusInfo) => {
      console.info(`CameraDemo camera: ${cameraStatusInfo.camera.cameraId}, status: ${cameraStatusInfo.status}`);
    });
  }

  async onPageShow(){
    await this.prepareCamera(this.ca);
  }

  build() {
    Column() {
      Column({ space: 10 }) {
        if (this.hasPicture) {
          Image(this.base64Str)
            .objectFit(ImageFit.Fill)
            .width('100%')
            .height(600)

          SaveButton(this.saveButtonOptions)// 创建安全控件按钮
            .onClick(async (event, result: SaveButtonOnClickResult) => {
              if (result == SaveButtonOnClickResult.SUCCESS) {
                if (this.finalPixelMap) {
                  try {
                    // 1、使用安全控件创建文件
                    let phAccessHelper: photoAccessHelper.PhotoAccessHelper = photoAccessHelper.getPhotoAccessHelper(this.context);
                    let options: photoAccessHelper.CreateOptions = {
                      title: Date.now().toString()
                    };
                    let photoUri: string = await phAccessHelper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'png', options);
                    console.info('CameraDemo createAsset successfully, photoUri: ' + photoUri);
                    let file: fileIo.File = fileIo.openSync(photoUri, fileIo.OpenMode.WRITE_ONLY);
                    fileIo.writeSync(file.fd, this.buffer);
                    fileIo.closeSync(file);
                    promptAction.showToast({message: `保存成功`})
                  } catch (error) {
                    let err = error as BusinessError;
                    console.error(`CameraDemo savePicture error: ${JSON.stringify(err)}`);
                    promptAction.showToast({ message: `保存失败` })
                  }
                }
              } else {
                console.error('CameraDemo SaveButtonOnClickResult createAsset failed.');
                promptAction.showToast({ message: `保存失败` })
              }
              setTimeout(() => {
                this.hasPicture = false;
                this.finalPixelMap = undefined;
              }, 1000)
            })

        } else {
          Row(){
            XComponent({
              id: '',
              type: 'surface',
              libraryname: '',
              controller: this.mXComponentController
            })
              .onLoad(() => {
                // 设置Surface宽高（1920*1080），预览尺寸设置参考前面 previewProfilesArray 获取的当前设备所支持的预览分辨率大小去设置
                // 预览流与录像输出流的分辨率的宽高比要保持一致
                this.mXComponentController.setXComponentSurfaceRect({offsetX:0,offsetY:0, surfaceWidth: this.screenHeight*0.49, surfaceHeight: this.screenWidth*0.49*1920/1080.0});
                // 获取Surface ID
                this.surfaceId = this.mXComponentController.getXComponentSurfaceId();
                setTimeout(async () => {
                  await this.prepareCamera(this.ca);
                }, 500);
              })
              .width(px2vp(this.screenWidth*0.49))
              .height(px2vp(this.screenWidth*0.49*1920/1080.0))

            Image(this.pixelMap)
              .margin({left:5})
              .width(px2vp(this.screenWidth*0.49))
              .height(px2vp(this.screenWidth*0.49*1920/1080.0))
          }

          Row(){
            Button('拍照').width(60).height(60).margin({ right: 10 }).borderRadius(30)
              .onClick(async () => {
                let photoCaptureSetting: camera.PhotoCaptureSetting = {
                  quality: camera.QualityLevel.QUALITY_LEVEL_HIGH, // 设置图片质量高
                  rotation: camera.ImageRotation.ROTATION_0 // 设置图片旋转角度0
                }
                // 1、通过拍照流实现：点击拍照
                await this.photoOutput?.capture(photoCaptureSetting).catch((error: BusinessError) => {
                  console.error(`CameraDemo Failed to capture the photo ${error.message}`); //不符合条件则进入
                })
                this.hasPicture = true;
              })

          }

          Row(){
            Button('前置摄像头')
              .size({ width: 100, height: 30 }).margin({ right: 10 })
              .onClick(async () => {
                this.ca=1
                console.debug('打开前置摄像头')
                await this.prepareCamera(this.ca);
              })
            Button('后置摄像头')
              .size({ width: 100, height: 30 }).margin({ left: 10 })
              .onClick(async () => {
                this.ca=0
                console.debug('打开后置摄像头')
                await this.prepareCamera(this.ca);
              })
          }
        }
      }
      .width('100%')
      .height('100%')
      .padding(15)
      .borderRadius(8)
    }
    .width('100%')
    .height('100%')
    .backgroundColor('#FFFFFF')
  }

  async prepareCamera(ca:Number) {
    this.releaseCamera()
    this.createCameraManager();

    if (!this.cameraManager) {
      console.error('CameraDemo cameraManager is undefined.')
      return;
    }

    // 获取支持指定的相机设备对象
    let cameraDevices: Array<camera.CameraDevice> = [];
    let CameraDevice:camera.CameraDevice
    try {
      cameraDevices = this.cameraManager.getSupportedCameras();
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo The getSupportedCameras call failed. error: ${JSON.stringify(err)}`)
    }

    cameraDevices.forEach((cameraDevice: camera.CameraDevice) => {
      console.info(`CameraDemo cameraId: ${cameraDevice.cameraId}, cameraPosition: ${cameraDevice.cameraPosition.toString()}, cameraType: ${cameraDevice.cameraType.toString()}, connectionType: ${cameraDevice.connectionType.toString()}`)
    })

    // 创建相机输入流

    try {
      if (ca==0) {
        CameraDevice = cameraDevices[0]
      }else {
        CameraDevice = cameraDevices[1]
      }
      this.cameraInput = this.cameraManager.createCameraInput(CameraDevice);

    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo createCaptureSession error. error: ${JSON.stringify(err)}`);
      return
    }
    // 监听cameraInput错误信息
    this.cameraInput.on('error', CameraDevice, (error: BusinessError) => {
      console.error(`CameraDemo Camera input error: ${JSON.stringify(error)}`);
    });

    // 打开相机
    try {
      await this.cameraInput.open();
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo cameraInput open error. error: ${JSON.stringify(err)}`);
    }

    // 获取指定的相机设备对象支持的模式
    let cameraSceneModes: Array<camera.SceneMode> = [];
    try {
      cameraSceneModes = this.cameraManager.getSupportedSceneModes(CameraDevice);
      cameraSceneModes.forEach((cameraSceneMode: camera.SceneMode) => {
        console.info(`CameraDemo cameraSceneMode: ${cameraSceneMode.toString()}`)
      })
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo The getSupportedSceneModes call failed. error: ${JSON.stringify(err)}`)
    }

    // 获取相机设备支持的输出流能力
    let cameraOutputCapability: camera.CameraOutputCapability = this.cameraManager.getSupportedOutputCapability(CameraDevice, camera.SceneMode.NORMAL_PHOTO)
    if (!cameraOutputCapability) {
      console.error('CameraDemo cameraManager.getSupportedOutputCapability error')
      return;
    }
    this.printCameraOutputCapability(cameraOutputCapability);
    let previewProfile = cameraOutputCapability.previewProfiles[0];
    cameraOutputCapability.previewProfiles.forEach((profile) => {
      if (profile.size.width == this.imageSize.width && profile.size.height == this.imageSize.height) {
        previewProfile = profile;
        return;
      }
    })
    this.imageSize = previewProfile.size;

    // 创建相机预览输出流
    try {
      this.previewOutput = this.cameraManager.createPreviewOutput(previewProfile, this.surfaceId);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo createCaptureSession error. error: ${JSON.stringify(err)}`);
      return
    }
    // 监听previewOutput错误信息
    this.previewOutput.on('error', (error: BusinessError) => {
      console.error(`CameraDemo previewOutput error: ${JSON.stringify(error)}`);
    });

    //双路预览: 创建 预览流2 输出对象
    try {
      this.imageReceiver = image.createImageReceiver(this.imageSize, image.ImageFormat.JPEG, 8);
      let imageReceiverSurfaceId: string = await this.imageReceiver.getReceivingSurfaceId()
      this.previewOutput2 = this.cameraManager.createPreviewOutput(previewProfile, imageReceiverSurfaceId);
      this.onImageArrival(this.imageReceiver);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo createImageReceiver error ${JSON.stringify(err)}`);
      return
    }

    // 创建拍照输出流
    try {
      let photoProfile = cameraOutputCapability.photoProfiles[0];
      cameraOutputCapability.photoProfiles.forEach((profile) => {
        if (profile.size.width == this.imageSize.width && profile.size.height == this.imageSize.height) {
          photoProfile = profile;
          return;
        }
      })
      this.photoOutput = this.cameraManager.createPhotoOutput(photoProfile);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo createPhotoOutput error ${JSON.stringify(err)}`);
    }
    if (this.photoOutput === undefined) {
      console.error('CameraDemo photoOutput is undefined.');
      return;
    }

    //调用上面的回调函数来保存图片
    this.setPhotoOutputCb(this.photoOutput);

    // 创建相机会话
    try {
      this.cameraSession = this.cameraManager.createSession<camera.PhotoSession>(camera.SceneMode.NORMAL_PHOTO);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo createCaptureSession error. error: ${JSON.stringify(err)}`);
      return
    }
    // 监听session错误信息
    this.cameraSession.on('error', (error: BusinessError) => {
      console.error(`CameraDemo Capture session error: ${JSON.stringify(error)}`);
    });

    // 开始会话配置
    try {
      this.cameraSession.beginConfig()
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo beginConfig error. error: ${JSON.stringify(err)}`);
    }

    // 向会话中添加相机输入流
    try {
      this.cameraSession.addInput(this.cameraInput)
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo addInput error. error: ${JSON.stringify(err)}`);
    }

    // 向会话中添加预览输出流
    try {
      this.cameraSession.addOutput(this.previewOutput)
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo add previewOutput error. error: ${JSON.stringify(err)}`);
    }
    // 向会话中添加拍照输出流
    try {
      this.cameraSession.addOutput(this.photoOutput);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo add photoOutput error. error: ${JSON.stringify(err)}`);
    }

    // 向会话中添加预览输出流2
    try {
      this.cameraSession.addOutput(this.previewOutput2)
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo add previewOutput2 error. error: ${JSON.stringify(err)}`);
    }

    // 提交会话配置
    try {
      await this.cameraSession.commitConfig();
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo captureSession commitConfig error: ${JSON.stringify(err)}`);
    }

    // 启动会话
    try {
      await this.cameraSession.start();
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo captureSession start error: ${JSON.stringify(err)}`);
    }

    // 配置相机的参数可以调整拍照的一些功能，包括闪光灯、变焦、焦距等。
    this.configuringSession(this.cameraSession)
  }

  configuringSession(photoSession: camera.PhotoSession): void {
    // 判断设备是否支持闪光灯
    let flashStatus: boolean = false;
    try {
      flashStatus = photoSession.hasFlash();
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo Failed to hasFlash. error: ${JSON.stringify(err)}`);
    }
    console.info(`CameraDemo Returned with the flash light support status: ${flashStatus}`);
    if (flashStatus) {
      // 判断是否支持自动闪光灯模式
      let flashModeStatus: boolean = false;
      try {
        let status: boolean = photoSession.isFlashModeSupported(camera.FlashMode.FLASH_MODE_AUTO);
        flashModeStatus = status;
      } catch (error) {
        let err = error as BusinessError;
        console.error(`CameraDemo Failed to check whether the flash mode is supported. error: ${JSON.stringify(err)}`);
      }
      if (flashModeStatus) {
        // 设置自动闪光灯模式
        try {
          photoSession.setFlashMode(camera.FlashMode.FLASH_MODE_AUTO);
        } catch (error) {
          let err = error as BusinessError;
          console.error(`CameraDemo Failed to set the flash mode. error: ${JSON.stringify(err)}`);
        }
      }
    }
    // 判断是否支持连续自动变焦模式
    let focusModeStatus: boolean = false;
    try {
      let status: boolean = photoSession.isFocusModeSupported(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO);
      focusModeStatus = status;
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo Failed to check whether the focus mode is supported. error: ${JSON.stringify(err)}`);
    }
    if (focusModeStatus) {
      // 设置连续自动变焦模式
      try {
        photoSession.setFocusMode(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO);
      } catch (error) {
        let err = error as BusinessError;
        console.error(`CameraDemo Failed to set the focus mode. error: ${JSON.stringify(err)}`);
      }
    }
    // 获取相机支持的可变焦距比范围
    let zoomRatioRange: Array<number> = [];
    try {
      zoomRatioRange = photoSession.getZoomRatioRange();
      zoomRatioRange.forEach(( index: number) => {
        console.info(`zoomRatioRange 支持的焦距: [${index}]`);
      })
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo Failed to get the zoom ratio range. error: ${JSON.stringify(err)}`);
    }
    if (zoomRatioRange.length <= 0) {
      return;
    }
    // 设置可变焦距比
    try {
      photoSession.setZoomRatio(1);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo Failed to set the zoom ratio value. error: ${JSON.stringify(err)}`);
    }
  }

  // 通过Surface进行数据传递，通过ImageReceiver的surface获取预览图像。
  async onImageArrival(receiver: image.ImageReceiver): Promise<void> {
    receiver.on('imageArrival', () => {
      receiver.readNextImage(async (err, nextImage: image.Image) => {
        //console.info(`enter CameraDemo imageArrival, nextImage: ${JSON.stringify(nextImage)}`)
        if (err || nextImage === undefined) {
          console.error(`CameraDemo imageArrival error, error is ${JSON.stringify(err)} or nextImage is undefined`)
          return;
        }
        nextImage.getComponent(image.ComponentType.JPEG, async (err, imgComponent: image.Component) => {
          if (err || imgComponent === undefined) {
            console.error(`CameraDemo getComponent error, error is ${JSON.stringify(err)} or imgComponent is undefined`)
            return;
          }
          if (imgComponent.byteBuffer as ArrayBuffer) {
            let sourceOptions: image.SourceOptions = {
              sourceDensity: 0,
              sourcePixelFormat: image.PixelMapFormat.NV21, // NV21
              sourceSize: this.imageSize
            }
            let imageSource: image.ImageSource = image.createImageSource(imgComponent.byteBuffer, sourceOptions);
            let opts: image.InitializationOptions = {
              editable: false,
              pixelFormat: image.PixelMapFormat.NV21,
              size: this.imageSize
            }
            let pixelMap = await imageSource.createPixelMap(opts);
            await pixelMap.rotate(270.0);
            this.pixelMap = pixelMap;
            await imageSource.release();
          } else {
            return;
          }
          nextImage.release()
        })
      })
    })
  }
  setPhotoOutputCb(photoOutput: camera.PhotoOutput) {
    //设置回调之后，调用photoOutput的capture方法，就会将拍照的buffer回传到回调中
    photoOutput.on('photoAvailable', (errCode: BusinessError, photo: camera.Photo): void => {
      console.info(`CameraDemo getPhoto start. err: ${JSON.stringify(errCode)}`);
      if (errCode || photo === undefined || photo.main === undefined) {
        console.error('CameraDemo getPhoto failed');
        return;
      }
      let imageObj = photo.main;
      imageObj.getComponent(image.ComponentType.JPEG, async (errCode: BusinessError, component: image.Component): Promise<void> => {
        console.info('CameraDemo getComponent start')
        if (errCode || component === undefined) {
          console.error('CameraDemo getComponent failed');
          return;
        }
        let imageBuffer: ArrayBuffer;
        if (component.byteBuffer) {
          imageBuffer = component.byteBuffer;
          this.buffer = imageBuffer;
          this.base64Str = "data:image/jpeg;base64,"+ buffer.from(imageBuffer).toString('base64')
          let sourceOptions: image.SourceOptions = {
            sourceDensity: 0, // 在不确定当前密度时传0
            sourcePixelFormat: image.PixelMapFormat.RGBA_8888,
            sourceSize: this.imageSize
          }
          let imageSource: image.ImageSource = image.createImageSource(imageBuffer, sourceOptions);
          let opts: image.InitializationOptions = {
            editable: false,
            pixelFormat: image.PixelMapFormat.RGBA_8888,
            size: this.imageSize
          }
          let pixelMap = await imageSource.createPixelMap(opts);
          this.finalPixelMap = pixelMap;
        } else {
          console.error('CameraDemo byteBuffer is null');
          return;
        }
      });
    });
  }

  printCameraOutputCapability(cameraOutputCapability: camera.CameraOutputCapability) {
    let previewProfileArr: Array<camera.Profile> = cameraOutputCapability.previewProfiles;
    let photoProfileArr: Array<camera.Profile> = cameraOutputCapability.photoProfiles;
    let videoProfileArr: Array<camera.VideoProfile> = cameraOutputCapability.videoProfiles;
    let supportedMetadataObjectTypeArr: Array<camera.MetadataObjectType> = cameraOutputCapability.supportedMetadataObjectTypes;
    previewProfileArr.forEach((value: camera.Profile, index: number) => {
      console.info(`CameraDemo 支持的预览尺寸: [${value.size.width},${value.size.height}]`);
    })
    photoProfileArr.forEach((value: camera.Profile, index: number) => {
      console.info(`CameraDemo 支持的拍照尺寸: [${value.size.width},${value.size.height}]`);
    })
    videoProfileArr.forEach((value: camera.VideoProfile, index: number) => {
      console.info(`CameraDemo 支持的录像尺寸: [${value.size.width},${value.size.height}], 支持的帧率范围: [${value.frameRateRange.min},${value.frameRateRange.max}]`);
    })
    supportedMetadataObjectTypeArr.forEach((value: camera.MetadataObjectType, index: number) => {
      console.info(`CameraDemo 支持的metadata流类型: ${value}`);
    })
  }

  releaseCamera() {
    if (this.cameraInput) {
      this.cameraInput.close()
    }
    if (this.previewOutput) {
      this.previewOutput.release()
    }
    if (this.photoOutput) {
      this.photoOutput.release()
    }
    if (this.cameraSession) {
      this.cameraSession.release()
    }
  }

  async imageWriteAlbumExample(pixelMap?:image.PixelMap) {
    console.info('createAssetDemo');
    let context = getContext(this);
    let phAccessHelper = photoAccessHelper.getPhotoAccessHelper(context);
    let photoType: photoAccessHelper.PhotoType = photoAccessHelper.PhotoType.IMAGE;
    let extension:string = 'jpg';
    let options: photoAccessHelper.CreateOptions = {
      title: 'testPhoto'
    }
    let uri = await phAccessHelper.createAsset(photoType, extension, options);
    // 使用uri打开文件，可以持续写入内容，写入过程不受时间限制
    try {
      if(pixelMap){
        // 方式一：通过文件管理写入文件
        let file =  fs.openSync(uri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
        const imageBuffer = await this.packingPixelMap2Jpg(pixelMap as image.PixelMap)
        // 写到媒体库文件中
        fs.writeSync(file.fd, imageBuffer);
        fs.closeSync(file.fd);
        // 方式二：通过imagePacker写入文件
        // let file: fs.File = fs.openSync(uri, fs .OpenMode.WRITE_ONLY);
        // let imagePacker: image.ImagePacker = image.createImagePacker();
        // let packOpts: image.PackingOption = { format: 'image/jpeg', quality: 100 };
        // await imagePacker.packToFile(pixelMap , file.fd, packOpts);
        // fs.closeSync(file);
      }
      promptAction.showToast({message: `保存成功`})
      promptAction.showToast({
        message: '已保存至相册',
        duration: 2500
      });

    }
    catch (err) {
      console.error("error is "+ JSON.stringify(err))
      promptAction.showToast({
        message: '保存失败',
        duration: 2000
      });
    }
  }

  async  packingPixelMap2Jpg(pixelMap: PixelMap): Promise<ArrayBuffer> {
    // 创建ImagePacker实例
    const imagePackerApi = image.createImagePacker();
    // 设置打包参数
    // format：图片打包格式，只支持 jpg 和 webp
    // quality：JPEG 编码输出图片质量
    // bufferSize：图片大小，默认 10M
    const packOpts: image.PackingOption = { format: "image/jpeg", quality: 100 };
    let imageBuffer: ArrayBuffer = new ArrayBuffer(1);
    try {
      // 图片压缩或重新打包
      imageBuffer = await imagePackerApi.packing(pixelMap, packOpts);
    } catch (err) {
      console.error(`Invoke packingPixelMap2Jpg failed, err: ${JSON.stringify(err)}`);
    }
    return imageBuffer;
  }
}

在HarmonyOS鸿蒙Next中，相机实时预览及对预览流数据进行实时处理，主要通过CameraKit和Camera API实现。首先，使用CameraKit初始化相机并配置预览参数，通过PreviewOutput获取实时预览数据流。然后，利用ImageReceiver或Surface接收每一帧图像数据，并结合Image类进行图像处理，如滤镜、人脸识别等。处理后的数据可通过SurfaceTexture显示或进一步传输。整个过程需在独立的线程中执行，确保实时性和性能优化。