Automatic SMIL Generation

The RealSystem ad serving feature uses SMIL to lay out clips and ads. You have the greatest flexibility when you set up your own SMIL file as described in "SMIL Files with Ad Content". However, RealServer can automatically generate a SMIL file that includes an ad when a single media clip is requested. If your site hosts a large number of RealVideo clips, for example, you can simply post the clips and have RealServer automatically generate the SMIL file and get the ad for you.

Automatic SMIL generation works only with RealServer's general ad serving feature, not with rotating banner ads. It allows for just one ad per requested clip. It lets you define banner ads or ads that appear before the clip. It also lets you define whether ads appear above, below, left of, right of, or in front of clips. The following sections explain how to set up automatic SMIL generation. You can edit the RealServer configuration file manually or use the Web-based RealSystem Administrator.

	Note
	The Web-based RealServer Administrator interface is not described in this document.

Overview of Automatic SMIL Generation

The following figure illustrates automatic SMIL generation:

Automatic SMIL Generation

1. A Web page has a hyperlink to a media clip on RealServer. This may be a RealVideo, RealFlash, RealAudio, RealPix, or RealText clip. The URL includes a mount point, such as /smilgen/banner/, that indicates the clip requires a SMIL file that includes an ad. For example, the request URL may look like this:

   
   <a href="http://realserver.company.com/ramgen/adtag/sports/smilgen/banner/content/video.rm">
   

   This example URL contains these components:

   realserver.company.com	RealServer address and, if necessary, HTTP port.
   /ramgen/	Mount point to cause the Ramgen utility to launch RealPlayer.
   /adtag/sports/	Mount point to cause RealServer to give the SMIL file for the requested clip to the tag handler plug-in and insert a "sports ad."
   /smilgen/banner/	Mount point that causes the SMIL generation plug-in to create a SMIL file for the requested clip, laying out a SMIL region for a banner ad.
   /video/	Optional directory containing the requested file. This directory is relative to the base path defined for the SMIL generation plug-in.
   video.rm	Requested clip.

   The SMIL generation mount point (/smilgen/banner/) simply follows the ad serving mount point (/adgen/sports/) in the request URL.

   	Note
   	For more on the ad serving mount points, see "General Ad Serving".

2. The /smilgen/banner/ mount point causes RealServer to uses its SMIL generation plug-in to create a SMIL file for the requested clip. The RealServer configuration file defines this mount point and associates it with the SMIL generation plug-in.

3. Based on the variables defined for the /smilgen/banner/ mount point, the SMIL generation plug-in creates SMIL mark-up that lays out and times the ad and requested clip. The configuration file associates the /smilgen/banner/ mount point with layout and timing attributes. For example, it might define a banner ad 468 pixels wide by 60 pixels high that appears above the clip as it plays.

   The configuration file may have additional mount points such as /smilgen/lead_in/ or /smilgen/banner_below/. Each mount point defines a different ad scenario. This lets you support any number of ad types through automatic SMIL generation.

4. The SMIL generation plug-in passes the SMIL file, which contains the URL to the requested clip and a <RealAdInsert/> tag, to the tag handler plug-in.

5. The tag handler then passes the SMIL file to the ad insertion plug-in, which expands the <RealAdInsert/> tag to contain an ad URL.

   	Additional Information
   	For more on the ad insertion process, see "General Ad Serving".

6. RealPlayer receives the SMIL file and requests the presentation clips.

Configuring RealServer for Automatic SMIL Generation

You can edit the RealServer configuration file, typically named rmserver.cfg, with any text editor. After editing the file, restart RealServer to put the new parameters into effect. Before editing the configuration file, make sure you understand the file's XML-based syntax.

	Additional Information
	See the configuration file appendixes in RealServer Administration Guide.

You set up each SMIL generation mount point within the configuration file's FSMount section. Each mount point is defined between <List Name="FSMount"> and that tag's corresponding </List> tag. The following example shows two mount points defined for banner ads and lead-in ads respectively:

<List Name="FSMount">
  <!-- SMIL generation plug-in for banner ads -->
  <List Name="Banner SMIL Generation">
    <Var ShortName="pn-smilgen"/>
    <Var MountPoint="/smilgen/banner/"/>
    <Var BaseMountPoint="/"/>
    <Var AdType="Banner"/>
    <Var Layout="AdTop"/>
    <Var AdWidth="468"/>
    <Var AdHeight="60"/>
    <Var OuterPadding="5"/>
    <Var InnerPadding="10"/>
    <Var BGColor="black"/>
  </List>
  <!-- SMIL generation plug-in for lead-in ads -->
  <List Name="Lead-in SMIL Generation">
    <Var ShortName="pn-smilgen"/>
    <Var MountPoint="/smilgen/leadin/"/>
    <Var BaseMountPoint="/"/>
    <Var AdType="Leadin"/>
    <Var Layout="AdCenter"/>
    <Var AdWidth="200"/>
    <Var AdHeight="200"/>
    <Var OuterPadding="5"/>
    <Var BGColor="red"/>
    <Var EnablePlaylist="True"/>
  </List>
</List>

List Name

The user-defined list name ("Banner SMIL Generation" and "Lead-in SMIL Generation" in the examples above) should identify the purpose of the mount point.

ShortName

RealServer identifies which plug-in to use through this encoded short name. Use the predefined SMIL generation plug-in short name: pn-smilgen.

MountPoint

The mount point defines the URL component that causes RealServer to pass the requested file to the SMIL generation plug-in. Define the mount point between forward slashes, such as /smilgen/banner/. The mount point cannot include spaces. The mount point follows the tag handler mount point in request URLs such as this:

<a href="http://realserver.company.com/ramgen/adtag/sports/smilgen/banner/video.rm">

When this URL is requested, RealServer turns the file over to the SMIL generation plug-in based on the /smilgen/banner/ mount point.

The SMIL generation mount point must be relative to the tag handler plug-in's BaseMountPoint variable. For example, if the tag handler has this base mount point:

<Var BaseMountPoint="/local/"/>

the SMIL generation plug-in has a mount point like this:

<Var MountPoint="/local/smilgen/banner/"/>

Or if the tag handler has this base mount point:

<Var BaseMountPoint="/"/>

the SMIL generation plug-in uses a mount point like this:

<Var MountPoint="/smilgen/banner/"/>

BaseMountPoint

The base mount point represents the actual file system mount point RealServer uses to find the requested file. For example, this variable:

<Var BaseMountPoint="/"/>

means RealServer uses the file system plug-in associated with the mount point "/" to locate the requested file. The value "/" typically indicates RealServer's default file system plug-in that locates unsecured files on local disks. So for this request:

<a href="http://realserver.company.com/ramgen/adtag/sports/smilgen/banner/video.rm">

RealServer locates the file with a UNIX path such as the following, depending on the directory path associated with the "/" mount point in the configuration file:

/realserver/content/start.smil

On Win32, the path may look like this:

G:\realserver\content\start.smil

If RealServer contains secure content, allowance is verified only on the initial request URL, not when RealServer accesses the actual file. This can create a security hole if the base mount point is "/" and secure content resides below this directory level. To prevent this, make the base mount point a directory, such as /local/, that does not lead to secure content.

AdType

This variable determines the type of ad used. It can have one of these values:

	Additional Information
	See also "Rich Media Ads".

Layout

This variable determines the ad's location relative to the requested clip. It can have one of the following values:

Here is an example used with a standard banner ad that appears above the requested clip:

<Var Layout="AdTop"/>

AdWidth

This variable must be set to the pixel width of the ad that will be used. The SMIL generation plug-in lays out the SMIL file with this value. The default value is the standard banner width of 468 pixels. The following example shows the width set to 200 pixels:

<Var AdWidth="200"/>

AdHeight

Set this variable to the pixel height of the ad that will be used. The default value is the standard banner height of 60 pixels. The following example shows the height set to 50 pixels:

<Var AdHeight="50"/>

OuterPadding

The OuterPadding variable determines how many pixels of space the SMIL generation plug-in adds between the contents and the RealPlayer border. You can use any positive integer value. The default is 5 pixels. This example adds 20 pixels of outer padding:

<Var OuterPadding="20"/>

InnerPadding

This variable determines the distance in pixels between the ad and the clip. It is ignored if the ad appears in front of the clip. You can use any positive integer value. The default is 5 pixels. This example adds 10 pixels of space between ad and clip:

<Var InnerPadding="10"/>

Inner and Outer Padding Examples

Suppose a banner ad appears above the clip and is wider than the clip. If the ad is 200 pixels wide, an outer padding value of 5 makes the RealPlayer window 210 pixels wide. The height of this window is the height of the ad, plus the height of the clip, plus the InnerPadding value, plus 10 pixels (5 pixels of outer padding at top and bottom).

BGColor

This variable determines the background color for the RealPlayer window. Empty space around the ad and clip appear in this color. The default is black. To specify a color value, use any RGB hexadecimal value (#RRGGBB) supported by HTML, or one of the following predefined color names, listed here with their corresponding hexadecimal values:

The following example makes the background color black:

<Var BGColor="black"/>

EnablePlaylist

The EnablePlaylist variable, which is False by default, determines whether the viewer has access to the RealPlayer playlist during a lead-in ad. It has no effect on banner ads. You can set this variable to True to allow the viewer to skip the lead-in ad clip:

<Var EnablePlaylist="True"/>

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This file last updated on 05/03/99 at 17:33:29.