harmony 鸿蒙Distributed Camera Development

2022-10-28
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Distributed Camera Development

When to Use

You can call the APIs provided by the Camera module to develop a distributed camera that provides the basic camera functions such as shooting and video recording.

How to Develop

Connect your calculator to a distributed device. Your calculator will call getCameras() to obtain the camera list and traverse the returned camera list to check ConnectionType of the Camera objects. If ConnectionType of a Camera object is CAMERA_CONNECTION_REMOTE, your calculator will use this object to create a CameraInput object. The subsequent call process is the same as that of the local camera development. For details about the local camera development, see Camera Development.

For details about the APIs, see Camera Management.

Connecting to a Distributed Camera

Connect the calculator and the distributed device to the same LAN.

Open the calculator and click the arrow icon in the upper right corner. A new window is displayed. Enter the verification code as prompted, and the calculator will be connected to the distributed device.

Creating an Instance

import camera from '@ohos.multimedia.camera'
import image from '@ohos.multimedia.image'
import media from '@ohos.multimedia.media'
import featureAbility from '@ohos.ability.featureAbility'

// Create a CameraManager object.
let cameraManager
await camera.getCameraManager(globalThis.Context, (err, manager) => {
    if (err) {
        console.error('Failed to get the CameraManager instance ${err.message}');
        return;
    }
    console.log('Callback returned with the CameraManager instance');
    cameraManager = manager
})

// Register a callback to listen for camera status changes and obtain the updated camera status information.
cameraManager.on('cameraStatus', (cameraStatusInfo) => {
    console.log('camera : ' + cameraStatusInfo.camera.cameraId);
    console.log('status: ' + cameraStatusInfo.status);
})

// Obtain the camera list.
let cameraArray
let remoteCamera
await cameraManager.getCameras((err, cameras) => {
    if (err) {
        console.error('Failed to get the cameras. ${err.message}');
        return;
    }
    console.log('Callback returned with an array of supported cameras: ' + cameras.length);
    cameraArray = cameras
})

for(let cameraIndex = 0; cameraIndex < cameraArray.length; cameraIndex++) {
    console.log('cameraId : ' + cameraArray[cameraIndex].cameraId)                          // Obtain the camera ID.
    console.log('cameraPosition : ' + cameraArray[cameraIndex].cameraPosition)              // Obtain the camera position.
    console.log('cameraType : ' + cameraArray[cameraIndex].cameraType)                      // Obtain the camera type.
    console.log('connectionType : ' + cameraArray[cameraIndex].connectionType)              // Obtain the camera connection type.
    if (cameraArray[cameraIndex].connectionType == CAMERA_CONNECTION_REMOTE) {
        remoteCamera = cameraArray[cameraIndex].cameraId
    }
}

// Create a camera input stream.
let cameraInput
await cameraManager.createCameraInput(remoteCamera).then((input) => {
    console.log('Promise returned with the CameraInput instance');
    cameraInput = input
})

For details about the subsequent steps, see Camera Development.