HbbTV 1.5 experiments
Hi all,
In collaboration with Vicometch-IK4, we did some tests of HbbTV 1.5 to see if we could manage to exploit Shared Motions[1] to add sync capabilities to existing smart TVs. The HbbTV 1.5 does not have any explicit support for synchronization, and while HbbTV 2.0 will bring this, lots of existing SmartTVs will not get these upgrades. If you are interested and have knowledge about HbbTV, we welcome any input on this initial experiment.
We quickly discovered that the media element of the TV is unable to provide a good user experience when slaving after a Shared Motion. It lacks variable playback rate, and skip operations are very slow. Our approach was therefore to request the media element to play from a given position. It will not be very correct, but instead of trying to correct the playback on the TV, we rather adjust the Shared Motion to match what the TV does. In this way, we’ve re-created a master-slave relation, with one master (the TV/Chromecast) and however many slaves you want.
Here is a film we made from our experiment with a Panasonic TV [2]:
Interestingly, we see that the currentTime reported by this TV fluctuates within around 250ms. We are however able to select the better samples and in that way provide a consistent experience. The TV we tested did need calibration, but this seemed to be hardware specific and consistent for skips, reloads and other content.
This test is of course IP based. We asked for some input on this for broadcasted content. It appears that we only would have streamevents to provide an estimated time (possibly to within a second), but perhaps even relatively rough estimates of the current position could be extracted and make for user friendly transitions between broadcasted and IP delivered content?
Of course, HbbTV 2.0 devices should be much better at all of this, and provide local synchronization to boot. However, we believe this experiment opens for an interesting transition phase, where current SmartTVs can provide at least some additional functionality for a vast number of users.
If there is any interest in testing other HbbTVs, we’re very willing to provide a simple web application for testing, including manual calibration. Please let us know!
Regards, Njål
[1]: Motion Corporation
