IWMPEvents::ScriptCommand method (wmp.h)

Article
4/26/2023

[The feature associated with this page, Windows Media Player SDK, is a legacy feature. It has been superseded by MediaPlayer. MediaPlayer has been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer instead of Windows Media Player SDK, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The ScriptCommand event occurs when a synchronized command or URL is received.

Syntax

void ScriptCommand(
  [in] BSTR scType,
  [in] BSTR Param
);

Parameters

[in] scType

Specifies the type of script command.

[in] Param

Specifies the script command.

Return value

None

Remarks

Commands can be embedded along with the audio, video, or other data within a Windows Media file. The commands are comprised of a pair of Unicode strings associated with a designated time in the stream.

When playback reaches the time associated with the command, the Windows Media Player control sends a ScriptCommand event with two parameters. One parameter specifies the type of command being sent. The other parameter specifies the command. The type of parameter is used to determine how the command parameter is processed. Any type of command can be embedded in a Windows Media file to be handled by the ScriptCommand event.

The following table lists script command types that are processed automatically by Windows Media Player.

Type	Description
CAPTION	The control displays the associated text in the DIV specified by IWMPClosedCaption::get_captioningID.
EVENT	Tells the control to execute instructions defined for the specified event.
FILENAME	The control resets its URL property, attempts to open the specified file, and begins playing the new stream immediately.
OPENEVENT	Buffers the associated EVENT command for timely execution of the EVENT script.
SYNCHRONIZEDLYRICLYRIC	The Param parameter contains the synchronized lyric text. Windows Media Player displays the lyric text in the closed caption area of the Now Playing feature.
TEXT	The control displays the associated text in the DIV specified by IWMPClosedCaption::get_captioningID.
URL	The control automatically opens the URL specified using the default Internet browser if the IWMPSettings::put_invokeURLs method has been called.

You can embed any other type of command as long as you provide reciprocal code to handle the command. Unknown commands are ignored by the Windows Media Player control, but they are still handed off to the ScriptCommand event.

The ScriptCommand event is not called if the file is being scanned in fast forward or fast reversed mode.

The value of event parameters is specified by Windows Media Player. It can be accessed or passed to a method in an imported JScript file by using the parameter name. This parameter name must be typed exactly as shown, including capitalization.

URL commands received by the Windows Media Player control are invoked automatically in the user's default Web browser if the IWMPSettings::put_baseURL method has been called. You can use the IWMPSettings::put_defaultFrame property to specify the target frame in which the webpage appears.

The URL sent to Windows Media Player is processed relative to the base URL specified by the IWMPSettings::get_invokeURLs method. The base URL is concatenated with the relatively specified URL, resulting in a fully specified URL that is passed as the command parameter by the ScriptCommand event.

The Windows Media Player control always processes incoming URL commands in the following manner:

A URL command is received.
IWMPSettings::put_baseURL is used to create a full URL from the relative URL specified in the script command.
ScriptCommand is called.
After ScriptCommand returns, IWMPSettings::get_invokeURLs is checked.
If IWMPSettings::get_invokeURLs is true and the command is a URL command, the specified URL is invoked. If IWMPSettings::get_invokeURLs is false or the command is not a URL command, the command is ignored.

When authoring a Windows Media file, you can specify which frame the new URL is displayed in by concatenating two ampersand (&) characters and the name of the frame in the parameter field. The following example specifies that the URL http://myweb/mypage.html must be launched in the frame called myframe.


scType = "URL"
Param = http://myweb/mypage.html&&myframe

Requirements

Requirement	Value
Minimum supported client	Windows Media Player 9 Series or later.
Target Platform	Windows
Header	wmp.h
DLL	Wmp.dll

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