OpenHarmony相机开发

Posted 2023-02-19 Geek.Fan

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