Can HTML5 track element be used for *live* subtitles?

Question

I am planning to build a system to broadcast public events (trials, meetings, conferences).

A key request will be the insertion of live subtitles to the A/V stream.

The subtitles will be "live" since they will be produced by an operator while the event will happen.

I suppose the HTML5 "track" element is not yet implemented by any of the major browsers, but: can I expect to eventually use it for live subtitles? Will I be able to inject the subtitle to the page while the stream is playing?

Answer 1

Please Look at the following links. Looking at the link i am having to believe it should be possible as they are using Js to show subtitles

http://www.storiesinflight.com/js_videosub/

http://cuepoint.org/

You may also consider http://mozillapopcorn.org/ which is to show content on timing of the video. So technically u can use this with ajax to show/stream subtitles

Answer 2

There are HTML5 video JS libs that support subtitles (eg: VideoJS supports the .srt format, there are several easily Google-able others), however to the best of my knowledge none of them support streaming subtitles.

I think you may have to build your own solution for this. If I were to do it, I'd probably try doing something with Socket.IO's broadcast functionality that can push data out to all connected clients at once, and have your client-side JS listen for new subtitle events and render them on screen as they come in. You can use plain ol' CSS to overlay the text over the HTML5 video.