Re: Interactive Television

Hi Scott, Adam,

On Wed, Aug 10, 2011 at 12:10 AM, Scott Wilson
<scott.bradley.wilson@gmail.com> wrote:
> On 9 Aug 2011, at 14:27, Adam Sobieski wrote:
>
> Scott Bradley Wilson,
>
> Upon reading the WebVTT specification, it seems that even more HTML5 tags
> are possible in video transcripts. In particular, hyperlinks and multimedia
> object references. The computer as teleprompter with hypertext idea,
> illustrated in point 3, indicates how hypertext might come to be in a video
> blog transcript. Other possible techniques include speech recognition and
> video post-production software.
>
> In addition to text formats, XML and hypertext varieties of video tracks are
> of interest. Web development scenarios include combinations of video tracks
> with DHTML techniques. With something like <video ...><track kind="metadata"
> type="xml/temporal" onplayheadenter="callback1" onplayheadexit="callback2"
> src="file.xml"/></video>, multiple XML tracks can be synchronized to the
> playhead. The JavaScript event object can include XML fragments in the data
> structure.
>
> I don't think we've really explored what we can do with <track> and WebVTT
> yet. WebVTT provides a synchronised text track useful for subtitle and audio
> description with some formatting capabilities (position and style).

Yes, I agree. We should not invent another format to use in <track>
which browser will not implement support for. The WebVTT file has been
specified with sufficient flexibility to allow for such extensions as
timed metadata with hyperlinks and all the bells and whistles. It
won't parse as a caption or subtitle track, but as a metadata track.


> The
> reason it exists is to provide authors with a consistent text track format
> to expect in web documents (rather than the large number of competing
> subtitle formats around).

Yes, it's a platform for extensions.

> However, though it has been published by WHATWG it
> hasn't been taken up by W3C yet.

We're working on that: http://www.w3.org/2011/05/google-webvtt-charter.html .

> The <track> element can reference any content type, though it does expect it
> would contain time synchronization data.
> I suspect many use-cases could be realized by adding extensions to WebVTT -
> e.g. adding links to support contextual advertising overlays, or events to
> trigger web intents [1] such as opening an EPG information entry.

I'm wondering if we should standardise something more general - such
as timed JSON in cues. Then we can add any metadata format into it and
it can get exposed easily to JavaScript.

If we are thinking of more concrete use cases - such as overlayed
annotations with hyperlinks - we should consider introducing a new
track @kind value for this and some markup.

Cheers,
Silvia.

Received on Thursday, 11 August 2011 04:41:27 UTC