OpenHarmony相机开发_openharmony camera

作者：凡人多烦事01 | 2024-03-28 09:47:40

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openharmony camera

1、OpenHarmony相机开发简介

OpenHarmony相机模块支持相机业务的开发，开发者可以通过已开放的接口实现相机硬件的访问、操作和新功能开发，最常见的操作如：预览、拍照和录像等。开发者也可以通过合适的接口或者接口组合实现闪光灯控制、曝光时间控制、手动对焦和自动对焦控制、变焦控制以及更多的功能。

开发者在调用Camera能力时，需要了解Camera的一些基本概念：

相机静态能力：用于描述相机的固有能力的一系列参数，比如朝向、支持的分辨率等信息。
物理相机：物理相机就是独立的实体摄像头设备。物理相机ID是用于标志每个物理摄像头的唯一字串。
异步操作：为保证UI线程不被阻塞，部分Camera接口采用异步调用方式。异步方式API均提供了callback函数和Promise函数。

2、OpenHarmony相机开发流程及接口说明

接口说明

详细API含义请参考：相机管理API文档

参考代码如下：


const PERMISSIONS: Array<string> = [
    'ohos.permission.CAMERA',
    'ohos.permission.MICROPHONE',
    'ohos.permission.MEDIA_LOCATION',
    'ohos.permission.READ_MEDIA',
    'ohos.permission.WRITE_MEDIA'
]
 
function applyPermission() {
        console.info('[permission] get permission');
        globalThis.abilityContext.requestPermissionFromUser(PERMISSIONS)
    }

(1)、创建相机实例：

在实现一个相机应用之前必须先创建一个独立的相机设备，然后才能继续相机的其他操作。如果此步骤操作失败，相机可能被占用或无法使用。如果被占用，必须等到相机释放后才能重新获取CameraManager对象。通过getSupportedCameras() 方法，获取当前使用的设备支持的相机列表。相机列表中存储了当前设备拥有的所有相机ID，如果列表不为空，则列表中的每个ID都支持独立创建相机对象；否则，说明正在使用的设备无可用的相机，不能继续后续的操作。相机设备具备预览、拍照、录像、Metadata等输出流，需要通过getSupportedOutputCapability()接口获取各个输出流的具体能力，通过该接口，可以获取当前设备支持的所有输出流能力，分别在CameraOutputCapability中的各个profile字段中，相机设备创建的建议步骤如下：


import camera from '@ohos.multimedia.camera'
import image from '@ohos.multimedia.image'
import media from '@ohos.multimedia.media'
 
// 创建CameraManager对象
context: any = getContext(this)
let cameraManager = camera.getCameraManager(this.context)
if (!cameraManager) {
    console.error("camera.getCameraManager error")
    return;
} 
// 监听相机状态变化
cameraManager.on('cameraStatus', (cameraStatusInfo) => {
    console.log(`camera : ${cameraStatusInfo.camera.cameraId}`);
    console.log(`status: ${cameraStatusInfo.status}`);
})
 
// 获取相机列表
let cameraArray = cameraManager.getSupportedCameras();
if (cameraArray.length <= 0) {
    console.error("cameraManager.getSupportedCameras error")
    return;
} 
 
for (let index = 0; index < cameraArray.length; index++) {
    console.log('cameraId : ' + cameraArray[index].cameraId);                        // 获取相机ID
    console.log('cameraPosition : ' + cameraArray[index].cameraPosition);              // 获取相机位置
    console.log('cameraType : ' + cameraArray[index].cameraType);                      // 获取相机类型
    console.log('connectionType : ' + cameraArray[index].connectionType);              // 获取相机连接类型
}
 
// 创建相机输入流
let cameraInput
try {
    cameraInput = cameraManager.createCameraInput(cameraArray[0]);
} catch () {
   console.error('Failed to createCameraInput errorCode = ' + error.code);
}
 
// 监听cameraInput错误信息
let cameraDevice = cameraArray[0];
cameraInput.on('error', cameraDevice, (error) => {
    console.log(`Camera input error code: ${error.code}`);
})
 
// 打开相机
await cameraInput.open();
 
// 获取相机设备支持的输出流能力
let cameraOutputCap = cameraManager.getSupportedOutputCapability(cameraArray[0]);
if (!cameraOutputCap) {
    console.error("cameraManager.getSupportedOutputCapability error")
    return;
}
console.info("outputCapability: " + JSON.stringify(cameraOutputCap));
 
let previewProfilesArray = cameraOutputCap.previewProfiles;
if (!previewProfilesArray) {
    console.error("createOutput previewProfilesArray == null || undefined")
} 
 
let photoProfilesArray = cameraOutputCap.photoProfiles;
if (!photoProfilesArray) {
    console.error("createOutput photoProfilesArray == null || undefined")
} 
 
let videoProfilesArray = cameraOutputCap.videoProfiles;
if (!videoProfilesArray) {
    console.error("createOutput videoProfilesArray == null || undefined")
} 
 
let metadataObjectTypesArray = cameraOutputCap.supportedMetadataObjectTypes;
if (!metadataObjectTypesArray) {
    console.error("createOutput metadataObjectTypesArray == null || undefined")
}
 
// 创建预览输出流,其中参数 surfaceId 参考下面 XComponent 组件，预览流为XComponent组件提供的surface
let previewOutput
try {
    previewOutput = cameraManager.createPreviewOutput(previewProfilesArray[0], surfaceId)
} catch (error) {
    console.error("Failed to create the PreviewOutput instance.")
}
 
// 监听预览输出错误信息
previewOutput.on('error', (error) => {
    console.log(`Preview output error code: ${error.code}`);
})
 
// 创建ImageReceiver对象，并设置照片参数：分辨率大小是根据前面 photoProfilesArray 获取的当前设备所支持的拍照分辨率大小去设置
let imageReceiver = await image.createImageReceiver(1920, 1080, 4, 8)
// 获取照片显示SurfaceId
let photoSurfaceId = await imageReceiver.getReceivingSurfaceId()
// 创建拍照输出流
let photoOutput
try {
    photoOutput = cameraManager.createPhotoOutput(photoProfilesArray[0], photoSurfaceId)
} catch (error) {
   console.error('Failed to createPhotoOutput errorCode = ' + error.code);
}
 
// 创建视频录制的参数
let videoConfig = {
    audioSourceType: 1,
    videoSourceType: 1,
    profile: {
        audioBitrate: 48000,
        audioChannels: 2,
        audioCodec: 'audio/mp4v-es',
        audioSampleRate: 48000,
        durationTime: 1000,
        fileFormat: 'mp4',
        videoBitrate: 48000,
        videoCodec: 'video/mp4v-es',
        videoFrameWidth: 640,
        videoFrameHeight: 480,
        videoFrameRate: 30
    },
    url: 'file:///data/media/01.mp4',
    orientationHint: 0,
    maxSize: 100,
    maxDuration: 500,
    rotation: 0
}
 
// 创建录像输出流
let videoRecorder
media.createVideoRecorder().then((recorder) => {
    console.log('createVideoRecorder called')
    videoRecorder = recorder
})
// 设置视频录制的参数
videoRecorder.prepare(videoConfig)
//获取录像SurfaceId
let videoSurfaceId
videoRecorder.getInputSurface().then((id) => {
    console.log('getInputSurface called')
    videoSurfaceId = id
})
 
// 创建VideoOutput对象
let videoOutput
try {
    videoOutput = cameraManager.createVideoOutput(videoProfilesArray[0], videoSurfaceId)
} catch (error) {
    console.error('Failed to create the videoOutput instance. errorCode = ' + error.code);
}
 
// 监听视频输出错误信息
videoOutput.on('error', (error) => {
    console.log(`Preview output error code: ${error.code}`);
})

预览流、拍照流和录像流的输入均需要提前创建surface，其中预览流为XComponent组件提供的surface，拍照流为ImageReceiver提供的surface，录像流为VideoRecorder的surface。

XComponent


mXComponentController: XComponentController = new XComponentController                   // 创建XComponentController
 
build() {
    Flex() {
        XComponent({                                                                     // 创建XComponent
            id: '',
            type: 'surface',
            libraryname: '',
            controller: this.mXComponentController
        })
        .onload(() => {                                                                  // 设置onload回调
            // 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
            this.mXComponentController.setXComponentSurfaceSize({surfaceWidth:1920,surfaceHeight:1080})
            // 获取Surface ID
            globalThis.surfaceId = mXComponentController.getXComponentSurfaceId()
        })
        .width('1920px')                                                                 // 设置XComponent宽度
        .height('1080px')                                                                // 设置XComponent高度
    }
}

ImageReceiver


function getImageReceiverSurfaceId() {
    let receiver = image.createImageReceiver(640, 480, 4, 8)
    console.log(TAG + 'before ImageReceiver check')
    if (receiver !== undefined) {
      console.log('ImageReceiver is ok')
      surfaceId1 = receiver.getReceivingSurfaceId()
      console.log('ImageReceived id: ' + JSON.stringify(surfaceId1))
    } else {
      console.log('ImageReceiver is not ok')
    }
  }

VideoRecorder


function getVideoRecorderSurface() {
        await getFd('CameraManager.mp4');
        mVideoConfig.url = mFdPath;
        media.createVideoRecorder((err, recorder) => {
            console.info('Entering create video receiver')
            mVideoRecorder = recorder
            console.info('videoRecorder is :' + JSON.stringify(mVideoRecorder))
            console.info('videoRecorder.prepare called.')
            mVideoRecorder.prepare(mVideoConfig, (err) => {
                console.info('videoRecorder.prepare success.')
                mVideoRecorder.getInputSurface((err, id) => {
                    console.info('getInputSurface called')
                    mVideoSurface = id
                    console.info('getInputSurface surfaceId: ' + JSON.stringify(mVideoSurface))
                })
            })
        })
    }

(2)、创建相机实例


//创建会话
let captureSession
try {
    captureSession = cameraManager.createCaptureSession()
} catch (error) {
    console.error('Failed to create the CaptureSession instance. errorCode = ' + error.code);
}
 
// 监听session错误信息
captureSession.on('error', (error) => {
    console.log(`Capture session error code: ${error.code}`);
})
 
// 开始配置会话
try {
    captureSession.beginConfig()
} catch (error) {
    console.error('Failed to beginConfig. errorCode = ' + error.code);
}
 
// 向会话中添加相机输入流
try {
    captureSession.addInput(cameraInput)
} catch (error) {
    console.error('Failed to addInput. errorCode = ' + error.code);
}
 
// 向会话中添加预览输入流
try {
    captureSession.addOutput(previewOutput)
} catch (error) {
    console.error('Failed to addOutput(previewOutput). errorCode = ' + error.code);
}
 
// 向会话中添加拍照输出流
try {
    captureSession.addOutput(photoOutput)
} catch (error) {
    console.error('Failed to addOutput(photoOutput). errorCode = ' + error.code);
}
 
// 提交会话配置
await captureSession.commitConfig()
 
// 启动会话
await captureSession.start().then(() => {
    console.log('Promise returned to indicate the session start success.');
})

(3)、切换回话


// 停止当前会话
await captureSession.stop()
 
// 开始配置会话
try {
    captureSession.beginConfig()
} catch (error) {
    console.error('Failed to beginConfig. errorCode = ' + error.code);
}
 
// 从会话中移除拍照输出流
try {
    captureSession.removeOutput(photoOutput)
} catch (error) {
    console.error('Failed to removeOutput(photoOutput). errorCode = ' + error.code);
}
 
// 向会话中添加录像输出流
try {
    captureSession.addOutput(videoOutput)
} catch (error) {
    console.error('Failed to addOutput(videoOutput). errorCode = ' + error.code);
}
 
// 提交会话配置
await captureSession.commitConfig()
 
// 启动会话
await captureSession.start().then(() => {
    console.log('Promise returned to indicate the session start success.');
})

（4）、参数设置


// 判断设备是否支持闪光灯
let flashStatus
try {
    flashStatus = captureSession.hasFlash()
} catch (error) {
    console.error('Failed to hasFlash. errorCode = ' + error.code);
}
console.log('Promise 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
    try {
        let status = captureSession.isFlashModeSupported(camera.FlashMode.FLASH_MODE_AUTO)
        flashModeStatus = status
    } catch (error) {
        console.error('Failed to check whether the flash mode is supported. errorCode = ' + error.code);
    }
    if(flashModeStatus) {
        // 设置自动闪光灯模式
        try {
            captureSession.setFlashMode(camera.FlashMode.FLASH_MODE_AUTO)
        } catch (error) {
            console.error('Failed to set the flash mode. errorCode = ' + error.code);
        }
    }
}
 
// 判断是否支持连续自动变焦模式
let focusModeStatus
try {
    let status = captureSession.isFocusModeSupported(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO)
    focusModeStatus = status
} catch (error) {
    console.error('Failed to check whether the focus mode is supported. errorCode = ' + error.code);
}
 
if (focusModeStatus) {
    // 设置连续自动变焦模式
    try {
        captureSession.setFocusMode(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO)
    } catch (error) {
        console.error('Failed to set the focus mode. errorCode = ' + error.code);
    }
}
 
// 获取相机支持的可变焦距比范围
let zoomRatioRange
try {
    zoomRatioRange = captureSession.getZoomRatioRange()
} catch (error) {
    console.error('Failed to get the zoom ratio range. errorCode = ' + error.code);
}
 
// 设置可变焦距比
try {
    captureSession.setZoomRatio(zoomRatioRange[0])
} catch (error) {
    console.error('Failed to set the zoom ratio value. errorCode = ' + error.code);
}

（5）、拍照


let settings = {
    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
}
// 使用当前拍照设置进行拍照
photoOutput.capture(settings, async (err) => {
    if (err) {
        console.error('Failed to capture the photo ${err.message}');
        return;
    }
    console.log('Callback invoked to indicate the photo capture request success.');
});

（6）、录像


// 启动录像输出流
videoOutput.start(async (err) => {
    if (err) {
        console.error('Failed to start the video output ${err.message}');
        return;
    }
    console.log('Callback invoked to indicate the video output start success.');
});
 
// 开始录像
videoRecorder.start().then(() => {
    console.info('videoRecorder start success');
}
 
// 停止录像
videoRecorder.stop().then(() => {
    console.info('stop success');
}
 
// 停止录像输出流
videoOutput.stop((err) => {
    if (err) {
        console.error('Failed to stop the video output ${err.message}');
        return;
    }
    console.log('Callback invoked to indicate the video output stop success.');
});

（7）、资源释放


// 停止当前会话
captureSession.stop()
 
// 释放相机输入流
cameraInput.close()
 
// 释放预览输出流
previewOutput.release()
 
// 释放拍照输出流
photoOutput.release()
 
// 释放录像输出流
videoOutput.release()
 
// 释放会话
captureSession.release()
 
// 会话置空
captureSession = null

3、应用使用相机的流程图

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