Trkd™ Video FAQ


How do I display a WebVMT video?

There are two ways to load video and WebVMT files.

Click the load button, and choose files from the panel that appears.
Alternatively, drag files from your desktop and drop them onto the player in the browser window.

How do I change the appearance, e.g. colour, of a track?

Edit the WebVMT file in a text editor to change its CSS Style block attributes.
Reload the WebVMT file to see the changes made.

How do I clear the display?

Click the clear button to clear the video display, map presentation and any error messages shown.



Who else can see my WebVMT videos?

Video and WebVMT files must be accessible to the computer which is running the web browser and is connected to the internet.

  • The files do not leave that computer.
  • They are not sent across the Internet.
  • They are not copied to a remote server.

The only people who can see them are those who have access to that computer.

If you are using a public-access computer, e.g. in an internet cafe or a library, we strongly recommend that you delete your video and WebVMT files from that computer before logging out in order to protect your private information.

What are the other privacy issues?

Please read the Privacy section of the TrkdCam FAQ for more information.



Why does my video file not display?

Only video formats supported by your web browser can be displayed. Please check the format of your video file, and whether your web browser supports the same video and audio codecs and container format as your file.

MPEG-4 3 12 OS dependent 9 24 3.1
OGG 3 17 3.5 9 10.5 No
WebM 6 17 4 No 10.6 WebRTC

Read the HTML5 browser support page on Wikipedia for more details, or test your browser at the HTML5 test website.

Why does my WebVMT file not display?

WebVMT files must comply with the WebVMT documentation.

  1. Load your file into a text editor to confirm that it contains WebVMT content.
  2. Check whether a red error message is displayed when your file is loaded into Trkd Video and correct the issue.
    Trkd Video Error
  3. Check the web browser's console to see any error messages from Trkd Video.
  4. Report the issue to our support team, listing any errors given and enclosing a copy of your WebVMT file.

Why does loading my WebVMT file give an error?

The red error message indicates why there has been a problem.
Trkd Video Error
Here are the most common ones, with solutions.

Could not parse: filename

The WebVMT file was missing.
Check that the file name and type are correct, and that the file has sufficient access permissions.

Missing track attribute: attribute

The <track> HTML element was missing a required attribute.
Check that the following attributes are included:

for id attribute of the associated <div> element to display the map
tileurl url of map tiles, e.g. https://{s}{z}/{x}/{y}.png
src url of the WebVMT file (omitted for file loader)

WebVMT syntax errors

The WebVMT file was incorrectly formatted.
Check the details of the error message and WebVMT documentation to identify the problem. Load the WebVMT file into a text editor to correct the formatting error and then reload the modified version into the web browser.




Please read the Quick Guide for a simple introduction.