Can I use video subtitle tracks to synchronize an entity?

CesiumJS
1

Hello, can I use subtitle tracks to synchronize an entity in a map with a video. Like this:

WEBVTT

0

00:00:00.033 --> 00:00:16.049

13.71, 51.17

1

00:00:16.049 --> 00:00:48.081

13.68, 51.17

…

Many greetings from Germany!

Alexander

2

Hello,

I don’t quite understand what you’re trying to accomplish. Could you elaborate a little more?

Best,

Hannah

3

20170119_slubApp_screenshot.jpg
20170119_slubApp_screenshot.jpg1364×659 343 KB

​

Hallo Hanna,

this is my App. A Video with a Cesiumjs overlay to show the locations of the Clips.

“The ability to use structured data in cues makes the track element extremely powerful and flexible. A web app can listen for cue events, extract the text of each cue as it fires, parse the data and then use the results to make DOM changes (or perform other JavaScript or CSS tasks) synchronised with media playback. This technique is used to synchronise video playback and map marker position…”

(https://www.html5rocks.com/en/tutorials/track/basics)

Is there a Cesium example to control the position of a marker (entity) with a Html5 Video Track Element?

Best regards

Alexander

4

Hi Alexander,

Sorry, but we don’t have an example for syncing a subtitle track. We do have this example for how to sync a video with the timeline: http://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=Video.html&label=Showcases

Best,

Hannah

5

Thank you Hannah for your response. There are much more things I try to figure out, but I know that you are doing your best to make cesium a great tool for web 3d Geovisualization. But if you have time, here is my wishlist for cesium examples :slight_smile:

  1. ‘Html 5 Video Track’ in synchronization (if possible) with cesium
  2. direct ‘Marker URL Link’ to other websites
  3. easy Infobox description fullscreen (I tried it many times but it seems impossible.)
  4. geojson text labels
  5. an easy way to use Contour DEM (digital elevation models) as terrain tiles --> http://www.opendem.info/download_contours.html

Many greeting

Alexander from Dresden (Germany)

6

Thanks for the suggestions Alexander!

Can you explain #2 a little more? I’m not quite sure what you mean.

For #3, it shouldn’t be too hard to add a fullscreen button to the infobox. The code that creates the infobox is here: https://github.com/AnalyticalGraphicsInc/cesium/tree/master/Source/Widgets/InfoBox

You would add the button element in InfoBox.js, data-bind it to a function in InfoBoxViewModel.js that would control adding a fullscreen CSS class to the infobox, then you can change the size when that class is present in InfoBox.css.

You can find instructions for downloading and building the code base here: https://github.com/AnalyticalGraphicsInc/cesium/tree/master/Documentation/Contributors/BuildGuide

For #4, are text labels part of the GeoJSON spec? If so, I’ll write up an issue to add them.

For #5, Cesium doesn’t have direct support for DEM models, but AGI (the company that employs the Cesium team) has a product called the STK Terrain Server that can convet DEMs into quantized mesh terrain files. You can learn more about that here: http://www.agi.com/products/stk/terrain-server/

We also plan to have this capability as part of our upcoming cesium.com service. You can learn more about that here: https://www.cesium.com/

Best,

Hannah

7

Hi Alexander,

I realise that my response is very late, but thought might be interested to know there is now a proposal which addresses the first issue on your wishlist:

  1. ‘Html 5 Video Track’ in synchronization (if possible) with cesium

WebVMT is a metadata-focussed variant of WebVTT which can synchronise moving ‘entity’ paths with video using the HTML element in a web browser, including interpolation for frame accuracy.

Please add a comment to this issue to briefly outline your use case and help us ensure that the proposed solution addresses your requirements.

Many thanks for your support.

Rob