RealText and RealPix
By John Maxwell Hobbs
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RealNetworks'
has recently released the beta test version of its new G2 Player and
Server system. G2 stands for Generation 2, and represents a major step
forward for the company. With new system, RealNetworks has, for the
first time, embraced open standards. The player is based on a plug-in
architecture that allows for the relatively simple implementation of
new media types without having to download a new version each time a
that new protocol is supported. Currently the G2 player is only
available for Windows, but RealNetworks has promised versions for Mac
and Unix in the future. Perhaps the most significant advancement is the support of XML. The final release of the G2 player will support SMIL, or Synchronized Multimedia Integration Language the XML extension for the presentation of time-based multimedia recently recommended by the World Wide Web Consortium.
RealNetworks has also extended SMIL with two new media types: RealText
and RealPix. Both are XML-based declarative document formats and allow
sophisticated manipulation of text and image files. Both formats can be
used on their own, or incorporated into a SMIL presentation. In
addition to the ability to "stream" a preset list of text and images to
a player, the G2 system allows the "broadcast" of updated content to
connected players as will. This opens up possible applications such as
up to the minute news headlines or real-time stock tickers combined
with streaming audio and video presentations. RealText
RealText markup is quite similar to HTML and uses many of the same text
formatting tags. All contents of a RealText document are contained
within the <window> tag and are stored in files with the .rt
extension. There are four window types: generic (the default mode),
ScrollingNews, TickerTape, Marquee, and TelePrompter. The markup is
basically the same for all window types, the main difference is the
mode of presentation. For the purpose of this article, we will work
with the generic window type, which will allow the use of all the major
tags. The G2 authoring guide is available for free from RealNetworks
and covers all the window types in depth.
A generic .rt document, markup and all, is not much larger than its
text content. For example, to create a presentation that displays a new
line of text every 5 seconds looks like this:
<window>
The high railings of the Prospects rippled past their gaze.
<br><time begin="5">Dark poplars, rare white forms.
<br><time begin="10">forms more frequent,
<br><time begin="15">white shapes thronged amid the trees,
<br><time begin="20">white forms and fragments streaming by mutely,
<br><time begin="25">sustaining vain gestures on the air.
</time>
</time></time></time></time></window>
This is quite simple, and not all that exciting. The use of the
<clear/> tag in the next example, clears the window, and allows
for a more dynamic presentation of the same text.
<window>
The high railings of the Prospects rippled past their gaze.
<br><time begin="5"><clear>Dark poplars, rare white forms.
<br><time begin="10"><clear>Forms more frequent,
<time begin="15">white shapes thronged amid the trees,
<time begin="20">white forms and fragments streaming by mutely,
<time begin="25">sustaining vain gestures on the air.
</time>
</time></time></clear></time></clear></time></window>
The <time/> tags allow control over when text appears in a
presentation and the duration of its display. This allows for a greater
level of control than the use of the <clear/> tag:
<window>
The high railings of the Prospects rippled past their gaze.
<br><time begin="5"><clear>Dark poplars, rare white forms.
<time begin="10" end="17"><clear>Forms more frequent,
<time begin="15" end="22">white shapes thronged amid the trees,
<time begin="20" end="27">white forms and fragments streaming by mutely,
<time begin="25" end="30">sustaining vain gestures on the air.
<br><time begin="32" end="45">James Joyce - "Ulysses"
</time>
</time></time></time></clear></time></clear></time></window>
RealText supports appearance tags as well. Most of the basic HTML tags,
like bold, italic, underline, are supported, as well as ordered and
unordered lists and preformatted text. The <font/> tag supports
font size, face, color, and background color.
Hyperlinks are also supported and can be used to link to another .rt
file, launch a Web page in a browser window, execute a "mailto"
command, or RealPlayer commands.
The final example incorporates a number of appearance tags and a
hyperlink that launches a browser window and opens a Web page related
to the text:
<window>
<font face="Verdana, Arial, Helvetica" size="-1"><font size="-1"><font size="+2" face="helvetica">The high railings of the Prospects rippled
past their gaze.
<br><time begin="5"><clear>Dark poplars, rare white forms.
<time begin="10" end="17"><clear>Forms more frequent,
<time begin="15" end="22">white shapes thronged amid the trees,
<time begin="20" end="27">white forms and fragments streaming by mutely,
<time begin="25" end="30">sustaining vain gestures on the air.
<br><time begin="32" end="60"><a href="http://www.amazon.com/exec/obidos/ASIN/0679722769/cinemavolta">James
Joyce - <i>Ulysses</i></a></time></time></time></time></clear></time></clear></time></font>
</font></font></window>
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