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New Plugin Features

QuickTime 5 includes changes and additions to the browser Plugin.

In this section:

New Embed Tag Parameters
New URL Extensions
SaveEmbedTags
AllowEmbedTagOverrides
New Debug Tool Added to Plugin

New Embed Tag Parameters

The QuickTime browser plugin accepts two new EMBED tag parameters and a new URL extension that allows you to specify a set of EMBED tag parameters as part of a URL.

EMBED tag parameters are normally specified in HTML code as part of the EMBED tag. However, parameter values can also be stored inside a movie –– typically by an application such as Plugin Helper. And some parameters, such as AUTOPLAY, can also have their value set by user preferences.

This makes it possible to specify different settings for the same parameter in different places. You could set AUTOPLAY=True in your HTML, for example, while embedding AUTOPLAY=False in the movie using Plugin Helper. QuickTime resolves any such conflicts by giving first priority to HTML, next priority to settings embedded using Plugin Helper, and last priority to settings specified by user preferences.

As each parameter’s value is set by one of these methods, it is flagged to prevent its value from being overridden by a lower priority method. Unflagged parameters can still be set, allowing all methods to operate as long as none conflict.

The EMBED tag parameter settings can change when one movie replaces another, through the use of the QTNEXT or HREF parameter, for example, or through the action of an HREF track or a VR hotspot.

When one movie replaces another as specified in the QTNEXT parameter, the new movie inherits its parameter values from the current movie. Any values set in the HTML or embedded in the first movie are flagged, and take precedence over any values embedded in the new movie or the user preferences.

When one movie replaces another as specified in the HREF parameter, or as the result of an HREF Track action or a VR hotspot, the EMBED tag parameters are all reset to their default values. They are not flagged, however, so the defaults can be overridden by embedding the desired settings in the new movie.

The new EMBED tag parameters and URL extensions introduced in QuickTime 5 give you more control over these behaviors. You can now specify a set of explicit parameter values as part of a URL, instead of having to embed them in the new movie. You can also specify whether a new movie should inherit the current settings, and whether the current settings may be overridden (by settings embedded in the new movie or by the user preferences).

New URL Extensions

Some EMBED tag parameters, such as HREF, HOTSPOT, and QTNEXT, allow you to specify a URL. The QuickTime plugin can also parse URLs from HREF Tracks or text tracks inside a movie. A QuickTime URL extension allows these URLs to include a target, specified as part of the URL, using the syntax "<URL> T<target>". Note that the URL and the target specification are surrounded separately by angle brackets, and that quotes surround the URL and the extension jointly.

QuickTime 5 introduces a new URL extension that allows you to specify a separate set of EMBED tag parameters for each movie as part of the URL. This is easier and more flexible than having to embed settings in a movie using Plugin Helper, and it can be accomplished automatically at the HTML level by any script that can output a text file. The syntax is:

"<URL> T<Target> E<ParamA=Value ParamB=Value ... >"

For example, this code:

< EMBED SRC=Movie1.mov HEIGHT=256 WIDTH=320 CONTROLLER=False HREF="<Movie2.mov> T<myself> E<CONTROLLER=True AUTOPLAY=True>" >

uses HTML EMBED tag parameters to tell the QuickTime plugin to play Movie1.mov with no controller, leaving the AUTOPLAY parameter unspecified (controlled by user preferences). If the viewer clicks inside the display area of the movie, the HREF parameter tells the plugin to load Movie2.mov. The URL extensions T<> and E<> tell the plugin to replace the current movie (T<myself>), and set AUTOPLAY=True and CONTROLLER=True (E<AUTOPLAY=True CONTROLLER=True>).

Again, note that the URL itself is surrounded by angle brackets, and that a set of quotes surrounds the URL and all extensions.

Parameter values set using this method take precedence over any values embedded in the new movie using Plugin Helper or set by user preferences. You can change this using the new AllowEmbedTagOverrides parameter.

SaveEmbedTags

You can tell the QuickTime browser plugin to apply the current parameter values to a new movie by setting SaveEmbedTags=True. This causes a movie specified in an HREF parameter, for example, to behave like a movie loaded using the QTNEXT parameter — it inherits the current parameter values instead of being reset to the default values.

Example:

<EMBED SRC=ClickMe.mov HEIGHT=240 WIDTH=320 AUTOPLAY=True CONTROLLER=False LOOP=True HREF=YouClickedIt.mov TARGET=myself SAVEEMBEDTAGS=True >

This example would cause the plugin to autoplay ClickMe.mov in an endless loop with no controller. If the viewer clicked inside the movie’s display area, the plugin would load YouClickedIt.mov, which would also autoplay in a loop with no controller.

Like the values inherited through use of the QTNEXT parameter, the parameter values set using this method take precedence over any values embedded in the new movie using Plugin Helper or set by user preferences. You can change this using the new AllowEmbedTagOverrides parameter.

AllowEmbedTagOverrides

Setting the AllowEmbedTagOverrides parameter allows you to control whether the current parameter settings can be overridden by lower priority methods. This parameter can be set within your HTML or by embedding the parameter value in a movie, or both.

By default, EMBED tag parameter values set in HTML have higher priority than values embedded in a movie, which in turn take priority over user preferences. Similarly, when a movie inherits parameter values (because of the QTNEXT or SaveEmbedTags parameters), these inherited values take precedence over any values embedded in the movie itself, or specified by user preferences.

If you set AllowEmbedTagOverrides=True in your HTML, however, the current settings can be overridden by settings embedded in a movie using Plugin Helper, which in turn can be overridden by user preferences.

Bear in mind that this affects only parameters whose value you explicitly set. If you do not set a parameter’s value in your HTML, for example, that parameter can always be set by Plugin Helper or by the user preferences.

You would normally set AllowEmbedTagOverrides=True in your HTML to allow settings embedded in a new movie to take precedence over the current settings.

For example, when a new movie is specified by the QTNEXT parameter, or when the SaveEmbedTags parameter is set true, the new movie inherits the current parameter settings, and these settings take precedence over settings embedded in the new movie. By setting AllowEmbedTagOverrides to true, you can cause the new movie to inherit the current settings as default values, but override them with any settings embedded in the new movie.

Example:

<EMBED SRC=ClickMe.mov HEIGHT=240 WIDTH=320 CONTROLLER=False HREF=YouClickedIt.mov TARGET=myself SaveEmbedTags=True AllowEmbedTagOverrides=True >

In this example, when the viewer clicks in the display area of ClickMe.mov, the plugin loads YouClickedIt.mov. Because SaveEmbedTags is set True, the new movie inherits the parameter values set in the HTML (CONTROLLER=False) as well as any parameter settings embedded in ClickMe.mov, but because AllowEmbedTagOverrides is also true, these act as defaults that can be overriden by any settings embedded in YouClickedIt.mov, which could, for example, set CONTROLLER=True.

Note that when AllowEmbedTagOverrides=True, the AUTOPLAY parameter is controlled by the user’s QuickTime Settings control panel. If you set AllowEmbedTagOverrides=True in your HTML, and you want to control the AUTOPLAY parameter, you need to set AllowEmbedTagOverrides=False inside the new movie using a tool such as Plugin Helper. Otherwise, your setting will be overriden by the user’s preferences.

New Debug Tool Added to Plugin

QuickTime 5 adds a new tool to the Plugin that will help debug wired movies. The tool, which is simple and easy to use, is intended for QuickTime developers who are working specifically with wired movies. It works in this manner:

When the plug-in finds a media key named QTPIShowDebugMessages with the value “alert,” it puts up a dialog whenever it gets a sprite debug message. If the value is “debugger,” it drops into the low-level debuggeer (MacsBug or whatever is installed on your machine).

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