(HbbTV) `currentTime` is always `NaN` using `MediaSynchroniser`

Question

In an HbbTV application I am trying to get the currentTime of the video/broadcast object using the MediaSynchroniser object.

I have declared all needed objects, initialized the application, and made sure the a/v broadcast object is in the presenting state.

...
<object id="appmgr" type="application/oipfApplicationManager"></object>
<object id="broadcast" type="video/broadcast"></object>
<object type="application/hbbtvMediaSynchroniser" id="msync"></object>
...

Then I try to get the currentTime as follows:

function initMediaSync() {
      var msync = document.getElementById('msync');
      var broadcast = document.getElementById('broadcast');
      if (typeof msync.initMediaSynchroniser === "function") {
        try {
          msync.initMediaSynchroniser(broadcast, "urn:dvb:css:timeline:pts");

          setInterval(function () {
            log("Current Time: " + msync.currentTime);
          }, 1000)

          // setTimeout(switchVideo, 10000)
        } catch (e) {
          log('Error in media synchronisation: ' + e.message);
        }
      } else {
        log("Media Synchroniser not supported.");
      }
    }

Note: log is a previously defined function in order to debug the HbbTV application.

However, I'm always getting NaN as the msync.currentTime. What am I missing?

According to ETSI TS 103-736-1 - V1.1.1 (page 35, section 10.2.3) I should be able to use "urn:dvb:css:timeline:pts" as my timelineSelector.

When originalMediaObject is a video/broadcast object, PTS ("urn:dvb:css:timeline:pts") [...] shall be supported.