HarmonyOS鸿蒙Next中拍照比较慢的原因及优化方案

import camera from ‘@ohos.multimedia.camera’; import image from ‘@ohos.multimedia.image’; import abilityAccessCtrl from ‘@ohos.abilityAccessCtrl’; import common from ‘@ohos.app.ability.common’; import fs from ‘@ohos.file.fs’; import { BusinessError } from ‘@kit.BasicServicesKit’; import PhotoAccessHelper from ‘@ohos.file.photoAccessHelper’; import { ifaa } from ‘@kit.OnlineAuthenticationKit’;

@Entry @Component struct Index3 { @State message: string = ‘Hello World’ private mXComponentController: XComponentController = new XComponentController; private surfaceId: string = ‘-1’; @State imgUrl: PixelMap | undefined = undefined; private context: ESObject = undefined private previewProfilesObj2: camera.Profile | undefined = undefined; private receiver: image.ImageReceiver | undefined = undefined; @State pixma: PixelMap | undefined = undefined @State photoOutput: camera.PhotoOutput | undefined = undefined;

aboutToAppear() { let context = getContext() as common.UIAbilityContext; abilityAccessCtrl.createAtManager().requestPermissionsFromUser(context, [‘ohos.permission.CAMERA’]).then(() => { this.createDualChannelPreview(this.surfaceId); }); }

onPageShow(): void { this.createDualChannelPreview(this.surfaceId); }

async createDualChannelPreview(XComponentSurfaceId: string): Promise<void> { let cameraManager = await camera.getCameraManager(getContext() as ESObject); let camerasDevices: Array<camera.CameraDevice> = cameraManager.getSupportedCameras(); let profiles: camera.CameraOutputCapability = cameraManager.getSupportedOutputCapability(camerasDevices[0]); let previewProfiles: Array<camera.Profile> = profiles.previewProfiles; this.previewProfilesObj2 = previewProfiles[0]; this.receiver = image.createImageReceiver(this.previewProfilesObj2.size.width, this.previewProfilesObj2.size.height, 2000, 8);

let imageReceiverSurfaceId: string = await this.receiver.getReceivingSurfaceId();
let previewOutput2: camera.PreviewOutput = cameraManager.createPreviewOutput(this.previewProfilesObj2, imageReceiverSurfaceId);

let photoProfilesArray: Array<camera.Profile> = profiles.photoProfiles;
try {
  this.photoOutput = cameraManager.createPhotoOutput(photoProfilesArray[0]);
} catch (error) {
  let err = error as BusinessError;
  console.error('Failed to createPhotoOutput errorCode = ' + err.code);
}

if (this.photoOutput === undefined) {
  return;
}

let cameraInput: camera.CameraInput = cameraManager.createCameraInput(camerasDevices[0]);
await cameraInput.open();

let captureSession: camera.CaptureSession = cameraManager.createCaptureSession();
captureSession.beginConfig();
captureSession.addInput(cameraInput);
captureSession.addOutput(previewOutput2);
try {
  captureSession.addOutput(this.photoOutput);
} catch (error) {
  let err = error as BusinessError;
  console.error('Failed to addOutput(photoOutput). errorCode = ' + err.code);
}
await captureSession.commitConfig();
await captureSession.start();
this.onImageArrival(this.receiver);
this.setPhotoOutputCb(this.photoOutput)

}

async savePicture(buffer: ArrayBuffer, img: image.Image) { const context = getContext(this); let photoAccessHelper: PhotoAccessHelper.PhotoAccessHelper = PhotoAccessHelper.getPhotoAccessHelper(context); let options: PhotoAccessHelper.CreateOptions = { title: Date.now().toString() }; let photoUri: string = await photoAccessHelper.createAsset(PhotoAccessHelper.PhotoType.IMAGE, ‘jpg’, options); let file: fs.File = fs.openSync(photoUri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); await fs.write(file.fd, buffer); fs.closeSync(file); img.release(); }

setPhotoOutputCb(photoOutput: camera.PhotoOutput) { photoOutput.on(‘photoAvailable’, (errCode: BusinessError, photo: camera.Photo): void => { console.info(‘getPhoto start’); console.info(err: ${JSON.stringify(errCode)}); if (errCode || photo === undefined) { console.error(‘getPhoto failed’); return; } let imageObj = photo.main; imageObj.getComponent(image.ComponentType.JPEG, (errCode: BusinessError, component: image.Component): void => { console.info(‘getComponent start’); if (errCode || component === undefined) { console.error(‘getComponent failed’); return; } let buffer: ArrayBuffer; if (component.byteBuffer) { buffer = component.byteBuffer; if (component.byteBuffer as ArrayBuffer) { let sourceOptions: image.SourceOptions = { sourceDensity: 120, sourceSize: { height: 240, width: 320 }, }; try { let imageResource = image.createImageSource(component.byteBuffer); imageResource.createPixelMap({}).then((res)=>{ this.pixma = res; }); } catch (error) { let err = error as BusinessError; console.error('Failed to addOutput(photoOutput). errorCode = ’ + err.code); } } else { return; } } else { console.error(‘byteBuffer is null’); return; } this.savePicture(buffer, imageObj); }); }); }

async onImageArrival(receiver: image.ImageReceiver): Promise<void> { receiver.on(‘imageArrival’, () => { console.error(“imageArrival callback”); receiver.readLatestImage((err, nextImage: image.Image) => { if (err || nextImage === undefined) { return; } nextImage.getComponent(image.ComponentType.JPEG, async (err, imgComponent: image.Component) => { if (err || imgComponent === undefined) { return; } this.saveImageToFile(imgComponent.byteBuffer); if (imgComponent.byteBuffer as ArrayBuffer) { let sourceOptions: image.SourceOptions = { sourceDensity: 120, sourcePixelFormat: 8, // NV21 sourceSize: { height: this.previewProfilesObj2!.size.height, width: this.previewProfilesObj2!.size.width }, }; let imageResource = image.createImageSource(imgComponent.byteBuffer, sourceOptions); let decodingOptions : image.DecodingOptions = { editable: true, desiredPixelFormat: 3, }; imageResource.createPixelMap(decodingOptions).then((res)=>{ this.imgUrl = res; }); } else { return; } nextImage.release(); }) }) }) }

saveImageToFile(data: ArrayBuffer) { const context = getContext(this); let filePath = context.tempDir + “/test.jpg”; console.info("path is " + filePath); let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); fs.write(file.fd, data, (err, writeLen) => { if (err) { console.info("write failed with error message: " + err.message + ", error code: " + err.code); } else { console.info(“write data to file succeed and size is:” + writeLen); fs.closeSync(file); } }); }

build() { Column() { Row() { Image(this.imgUrl).objectFit(ImageFit.None) }.width(‘100%’).height(‘50%’).backgroundColor(’#F0F0F0’) Row() { Button() { Text(“拍照”) .fontColor(Color.Black) .alignSelf(ItemAlign.Center) .onClick(() => { let settings: 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 mirror: false // 设置镜像使能开关(默认关) }; if (this.photoOutput){ this.photoOutput.capture(settings, (err: BusinessError) => { if (err) { console.error(Failed to capture the photo. error: ${JSON.stringify(err)}); return; } console.info(‘Callback invoked to indicate the photo capture request success.’); }); } }) }.width(100).height(100) Image(this.pixma) .width(200) .height(200) } } } }