SosGetResultVideo

SosGetResultVideo is a specific DataSource to parse Video data.

The class inherits directly from TimeSeriesDataSource.

There are specific properties for this DataSource.

Specific properties

These properties are members of customUrlParams.

API Reference

(1) Note that in case of the video stream, it is very important to define the responseFormat to activate the support of these parameters.

(2) Note these parameters are available only from OSH server >= 1.4.0

Parser

The underlaying stream is binary.

The first 8 bytes is the timestamp in millis.

The next 4 bytes define the frame length.

The next bytes are corresponding to a full NAL unit.

|--- 8 bytes timestamp ---|--- 4 bytes frame length ---|--- NAL UNIT ---|

From Server:

[..binary..data..]

After parsing:

{
    timeStamp: 1450559070000,
    data: {
      frameData: [..binary..NAL_UNIT...],
      roll: 0    
    } 
}  

Example

import SosGetResultVideo from 'osh-js/core/datasource/SosGetResultVideo';

const videoDataSource = new SosGetResultVideo("drone-Video", {
  protocol: 'ws',
  service: 'SOS',
  endpointUrl: 'sensiasoft.net:8181/sensorhub/sos',
  offeringID: 'urn:mysos:solo:video2',
  observedProperty: 'http://sensorml.com/ont/swe/property/VideoFrame',
  startTime: '2015-12-19T21:04:29.231Z',
  endTime: '2015-12-19T21:09:19.675Z',
  replaySpeed: 1.0
});

// Data are received through Broadcast channel in a separate thread.
// When you create a View object, it automatically subscribes to the corresponding datasource channel(s).
// If you don't have view, or don't need, you can directly subscribe to the channel

const videoBroadcastChannel = new BroadcastChannel(DATASOURCE_DATA_TOPIC + videoDataSource.id);
const videoDivElement = document.getElementById('datasource-video');

videoBroadcastChannel.onmessage = (message) => {
  if(message.data.type === 'data') {
    let dataEvent;
    for(let i=0;i < message.data.values.length;i++) {
      dataEvent =  message.data.values[i];
      dataEvent.data.frameData = message.data.values[i].data.frameData.slice(0,10);
      videoDivElement.value += JSON.stringify( [dataEvent]) + '\n';
    }
  }
}

// start streaming onclick
const runButtonElement = document.getElementById('run-datasource-button');
runButtonElement.onclick = () => videoDataSource.connect();

---