[media-and-entertainment] Synchronisation related use cases for Open Screen Protocol (#21)

chrisn has just created a new issue for https://github.com/w3c/media-and-entertainment:

== Synchronisation related use cases for Open Screen Protocol ==
The [Second Screen CG](https://www.w3.org/community/webscreens/) is developing the [Open Screen Protocol](https://webscreens.github.io/openscreenprotocol/), a new open standard protocol designed to support the [Presentation API](https://w3c.github.io/presentation-api/) and [Remote Playback API](https://w3c.github.io/remote-playback/).

With the Remote Playback API, a media element in a controlling web page (e.g., on a mobile or laptop device) can be put into a state in which the video is actually being rendered on another device (e.g., a TV).

The Presentation API allows a controlling web page to open another page on a receiver device, and a communication channel is established between the two pages for those pages to exchange messages.

At the recent Second Screen CG F2F meeting, I was asked me to request input from the Media & Entertainment IG for **synchronisation related use cases** to help with the development of the Open Screen Protocol.

For the Remote Playback API, a question arises around the level of accuracy that the media element's `currentTime` should have. One use case is simply showing the media playback position (i.e., time counter) in the controlling page. Arguably, as this typically shown with a resolution of 1 second, then the accuracy can be within, say, 0.5 seconds. But there may be other use cases in which having more accurate knowledge of the playback position is needed, for example, showing content on the controlling page that is intended to be closely synchronised with the media playback on the receiver device.

For the Presentation API, either the controlling or receiving web page may choose to play audio or video content, with additional content on the other device.

If you have such use cases, please leave a comment here to describe or link to them, so that we can then share with the CG.

Many thanks!

Please view or discuss this issue at https://github.com/w3c/media-and-entertainment/issues/21 using your GitHub account

Received on Thursday, 13 June 2019 10:16:07 UTC