HarmonyOS鸿蒙Next中摄像头双路预览调用setFrameRate函数设置帧率会出现四个错误情况

在一个相机session中,所有输出流必须使用相同的帧率,目前无法同时以不同帧率输出到多个目标;

建议先判断当前设备是否支持,然后在配置帧率

import { abilityAccessCtrl } from '@kit.AbilityKit';
import { camera } from '@kit.CameraKit';
import { image } from '@kit.ImageKit';

type NullUndef = null | undefined;

interface FrameRateRange {
    min: number;
    max: number;
}

@Entry
@Component
struct Index
{
    m_XComponentControllerPt: XComponentController = new XComponentController();

    async aboutToAppear(): Promise<void>
    {
        console.log( "FirstPage aboutToAppear" );

        await abilityAccessCtrl.createAtManager().requestPermissionsFromUser( this.getUIContext().getHostContext()!, [ 'ohos.permission.CAMERA' ] );
    }

    // --- 相机核心对象 ---
    private cameraManager: camera.CameraManager | NullUndef;
    private cameraInput: camera.CameraInput | NullUndef;
    private previewOutput: camera.PreviewOutput | NullUndef;
    private imageReceiver: image.ImageReceiver | NullUndef;
    private imageReceiverPreviewOutput: camera.PreviewOutput | NullUndef;
    private captureSession: camera.Session | NullUndef;

    async initCamera()
    {
        // 1. 获取CameraManager实例
        this.cameraManager = camera.getCameraManager( getContext( this ) );
        if( !this.cameraManager ) return;

        // 2. 获取相机设备（优先使用后置摄像头）
        const cameras = this.cameraManager.getSupportedCameras( );
        const cameraDevice = cameras.find( device => device.cameraPosition === camera.CameraPosition.CAMERA_POSITION_FRONT );
        if( !cameraDevice ) return;

        // 3. 创建相机输入流
        this.cameraInput = this.cameraManager.createCameraInput( cameraDevice );
        await this.cameraInput.open( );

        // 4. 获取相机输出能力，选取合适的预览配置
        const SupportedSceneModes = this.cameraManager.getSupportedSceneModes( cameraDevice );
        const cameraOutputCap = this.cameraManager.getSupportedOutputCapability( cameraDevice, camera.SceneMode.NORMAL_VIDEO );
        //const previewProfile = cameraOutputCap.previewProfiles[ cameraOutputCap.previewProfiles.length - 1 ];
        const previewProfile = cameraOutputCap.previewProfiles[ 0 ];

        // 5. 获取预览显示用的Surface ID（来自XComponent）
        let xComponentSurfaceId: string = this.m_XComponentControllerPt.getXComponentSurfaceId( );

        // 6. 创建用于显示的预览输出流
        this.previewOutput = this.cameraManager.createPreviewOutput( previewProfile, xComponentSurfaceId );

        // ========== 关键步骤：创建ImageReceiver用于获取帧数据 ==========
        // 创建ImageReceiver实例，分辨率建议与预览流保持一致
        this.imageReceiver = image.createImageReceiver(
            { width: previewProfile.size.width, height: previewProfile.size.height },
            image.ImageFormat.JPEG, // 相机原始数据通常为YUV格式
            10 // 缓冲区容量，推荐8
        );

        // 注册图像到达回调，每帧数据都会触发
        this.imageReceiver.on('imageArrival', async () =>
        {
            console.info( 'image arrival' );

            let img: image.Image | NullUndef = null;
            try {
                img = await this.imageReceiver?.readNextImage();
                if (img) {
                    // 获取图像组件（YUV数据）
                    const components = await img.getComponent( image.ComponentType.JPEG );
                    let p_width = img.size.width;
                    let p_height = img.size.height;

                    //其他业务代码。

                    img.release(); // 务必释放图像资源，防止内存泄漏
                }
            } catch (err) {
                console.error(`处理帧数据失败: ${err.code} - ${err.message}`);
            } finally {
            }
        });

        // 7. 创建第二条预览输出流，关联到ImageReceiver的Surface
        this.imageReceiverPreviewOutput = this.cameraManager.createPreviewOutput( previewProfile, await this.imageReceiver.getReceivingSurfaceId() );

        // 8. 创建相机会话并配置
        this.captureSession = this.cameraManager.createSession( camera.SceneMode.NORMAL_VIDEO );
        this.captureSession.beginConfig( );
        this.captureSession.addInput( this.cameraInput );
        this.captureSession.addOutput( this.previewOutput );
        this.captureSession.addOutput( this.imageReceiverPreviewOutput ); // 添加第二条预览流

        const previewOutputSupportedFrameRates = this.previewOutput.getSupportedFrameRates( );
        const imageReceiverPreviewOutputSupportedFrameRates = this.imageReceiverPreviewOutput.getSupportedFrameRates( );

        console.info(`previewOutput支持的帧率范围: ${JSON.stringify(previewOutputSupportedFrameRates)}`);
        console.info(`imageReceiverPreviewOutput支持的帧率范围: ${JSON.stringify(imageReceiverPreviewOutputSupportedFrameRates)}`);

        const targetFps = 30;

        const isPreviewSupportTarget = this.isFrameRateSupported(previewOutputSupportedFrameRates, targetFps);
        const isImageReceiverSupportTarget = this.isFrameRateSupported(imageReceiverPreviewOutputSupportedFrameRates, targetFps);

        console.info(`previewOutput是否支持${targetFps}fps: ${isPreviewSupportTarget}`);
        console.info(`imageReceiverPreviewOutput是否支持${targetFps}fps: ${isImageReceiverSupportTarget}`);

        if (isPreviewSupportTarget && isImageReceiverSupportTarget) {
            this.previewOutput.setFrameRate(targetFps, targetFps);
            this.imageReceiverPreviewOutput.setFrameRate(targetFps, targetFps);
            console.info(`成功设置帧率为${targetFps}fps`);
        } else {
            const maxCommonFps = this.getMaxCommonFrameRate(previewOutputSupportedFrameRates, imageReceiverPreviewOutputSupportedFrameRates);
            if (maxCommonFps > 0) {
                this.previewOutput.setFrameRate(maxCommonFps, maxCommonFps);
                this.imageReceiverPreviewOutput.setFrameRate(maxCommonFps, maxCommonFps);
                console.info(`使用最大共同支持帧率${maxCommonFps}fps`);
            } else {
                console.warn('未找到共同支持的帧率，使用默认设置');
            }
        }

        await this.captureSession.commitConfig();
        await this.captureSession.start();
    }

    /**
     * 判断帧率是否支持
     * @param supportedRates
     * @param targetFps
     * @returns
     */
    private isFrameRateSupported(supportedRates: Array<FrameRateRange>, targetFps: number): boolean {
        for (const range of supportedRates) {
            if (targetFps >= range.min && targetFps <= range.max) {
                return true;
            }
        }
        return false;
    }

    /**
     * 获取最大共同支持帧率
     * @param previewRates
     * @param imageReceiverRates
     * @returns
     */
    private getMaxCommonFrameRate(
        previewRates: Array<FrameRateRange>,
        imageReceiverRates: Array<FrameRateRange>
    ): number {
        let maxCommonFps = 0;
        
        for (const previewRange of previewRates) {
            for (const receiverRange of imageReceiverRates) {
                const overlapMin = Math.max(previewRange.min, receiverRange.min);
                const overlapMax = Math.min(previewRange.max, receiverRange.max);
                
                if (overlapMin <= overlapMax && overlapMax > maxCommonFps) {
                    maxCommonFps = overlapMax;
                }
            }
        }
        
        return maxCommonFps;
    }

    build()
    {
        RelativeContainer()
        {
            XComponent( {
                type: XComponentType.SURFACE,
                controller: this.m_XComponentControllerPt
            } )
                .width('100%')
                .height('30%')
                .onLoad( () =>
                {
                } )
                .onClick( () =>
                {

                } )

            Button()
            {
                Text( "打开摄像头" )
                    .fontSize( $r( 'app.float.page_text_font_size' ) )
            }
            .id( 'HelloWorld' )
            .fontSize( $r( 'app.float.page_text_font_size' ) )
            .fontWeight( FontWeight.Bold )
            .alignRules( {
                center: { anchor: '__container__', align: VerticalAlign.Center },
                middle: { anchor: '__container__', align: HorizontalAlign.Center }
            } )
            .onClick( () =>
            {
                this.initCamera();
            } )
        }
        .height( '100%' )
        .width( '100%' )
    }
}