The purpose of the smilText JavaScript engine is to provide an implementation of SMIL 3.0 smilText functionality within an HTML browser. This release has been tested with Firefox 3, IE-7, Opera and Safari.
The smilText engine has reasonably complete coverage of the features defined in the SMIL 3.0 SmilText External Profile. The smilText JavaScript engine allows source content to reside within the HTML markup (NB: not supported by all browsers), in a local file or on a server. Access may be via file I/O, via http streaming or via an RTSP server.
The initial code for the project was developed by Rodrigo Laiola Guimarães at CWI.
The HTML integrating the JavaScript engine must define the engine as follows:
<html ...>
<head>
...
<script language="JavaScript" type="text/javascript" src="scripts/cwi.smilText.Time.js"></script>
<script language="JavaScript" type="text/javascript" src="scripts/cwi.smilText.js"></script>
...
</head>
<body>
...
<body>
</html>
SmilText that is embedded within an HTML file should be placed within <smilText> tags, such as:
<div id="region01" style="background-color:red;width:500">
<smilText textColor="green">
This is an example of content in merry holiday colors.
<tev begin="2s"></tev>
This second sentence comes shortly after the first, based on an absolute offset.
<tev next="3s"></tev>
This third sentence get rendered three seconds after the previous, based on a relative offset.
<clear begin="7s"></clear>
Here we clear the rendering area, seven seconds into the presentation.
<tev next="3s"></tev>
Doei!
</smilText>
</div>
<script>
var docs = cwi.smilText.Parser.parseHTML();
docs[0].play();
</script>
(Note that this functionality is NOT supported by Internet Explorer, but it is possible in Firefox, Opera and Safari.)
The format of an external <smilText> fragment is shown below:
<smilText xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="smilText"> The is a bit of text. <tev begin="3s"/> Here, the line is continued after 3 seconds. <clear begin="2s"/> At 5 seconds into the text, the area is cleared and a new fragment starts. <clear begin="3s"/> </smilText>
A smilText object placed in an external file should have its path placed in the HTML source text as follows:
<div id="region02">
<script>
var doc1 = cwi.smilText.Parser.parseFile('examples/example18.xml', 'region2');
doc1.play();
</script>
</div>
(Note that this functionality is NOT supported by Safari, but it is possible in Firefox, Opera and IE7+.)
Ten very techie pages illustrate a host of browser-embedded smilText examples. Note that some pages have many simultaneous smilText fragments active at once. Consider them eye tests for your mind. The samples are:
- A set of simple external smilText file examples, including links to the sources.
- A set of structured external smilText file examples, including links to the sources.
- A set of motion-based embedded smilText file examples, including links to the sources.
- A set of browser-specific tests for Firefox, IE-7, Opera and Safari, all including links to the sources.
- This demonstrator shows how smilText JS can caption a YouTube video (NOT supported by Safari).
- This example shows how event listeners can be associated to the presentation of a smilText document.
- This example shows how to create smilText documents on the fly.
- This demo uses the smilText JavaScript implementation bundled as a Popcorn plug-in.
For more information on composing a timed text file using smilText, see the chapter on smilText, taken from the book SMIL 3.0: Interactive Multimedia for the Web, Mobile Devices and Daisy Talking Books.
The smilText JavaScript API lets you embed SMIL 3.0 smilText functionalities in your own Web pages with JavaScript. The API provides a number of utilities for adding and manipulating timed text content, allowing you to create interesting applications such as the Ambulant Captioner (discontinued).
If you're planning to use smilText JavaScript in a Web-based application, then you'll want to join the smilText JavaScript Developer Group. This is a useful place to ask questions, keep up-to-date on releases, and make suggestions for future versions.