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Re: [media] Track vs. tracks

From: Eric Carlson <eric.carlson@apple.com>
Date: Tue, 9 Mar 2010 11:42:08 -0800
Cc: 'HTML Accessibility Task Force' <public-html-a11y@w3.org>
Message-Id: <F5B5B599-55CE-4F8C-84B8-553A53C14EEE@apple.com>
To: John Foliot <jfoliot@stanford.edu>

On Mar 9, 2010, at 11:27 AM, John Foliot wrote:

> Hello All,
> 
> Just a question (2 actually) for clarification:
> 
> In the Media MultitrackAPI document there is reference to 'tracks' in the
> plural:
> <q>
> 	if (video.tracks[1].role == "caption") video.tracks[1].enabled =
> true;
> 		enables a caption track
> 
> 	if (video.tracks[2].role == "subtitle" && video.tracks[2].language
> == "fr") video.tracks[2].enabled = true;
> 		enables a French subtitle track
> </q>
> 
> However in the Media TextAssociations we introduce an element <track>:
> <q>
> <video src="video.ogv">
>  <track src="video_tad.srt" type="text/srt" language="en"
> role="textaudesc"></track>
> </video>
> </q>
> 
> *****
> Is this deliberate or intentional (mixing singular and plural)? Does it
> matter?
> 

  This is intentional - "tracks" is the proposed property on HTMLMediaElement, it returns a collection of 0 or more tracks:

interface HTMLMediaElement : HTMLElement {
  ...
  readonly attribute MediaTracks tracks;
  ...
};

interface MediaTracks {
  readonly attribute unsigned long length;
  caller getter MediaTrack item(in unsigned long index);
  caller getter MediaTrack namedItem(in DOMString name);
  ...
};

interface MediaTrack {
  readonly attribute DOMString name;
  readonly attribute DOMString role;
  readonly attribute DOMString type;
  readonly attribute DOMString media;
  readonly attribute DOMString language;
           attribute boolean enabled;
  ...
};

  In other words, each track in a movie (internal and external) is represented by a MediaTrack. All of the tracks in a movie are in the MediaTracks collection.

eric
Received on Tuesday, 9 March 2010 19:42:40 GMT

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