Registering DSP Plug-ins
[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 It has been superseded by MediaPlayer.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.]
To make your DSP plug-in available in Windows Media Player you must create the following registry subkeys and entries on the user's computer.
[HKEY_CLASSES_ROOT\CLSID\PluginClsid]
@=PluginClassFriendlyName
[HKEY_CLASSES_ROOT\CLSID\PluginClsid\InprocServer32]
@=PluginModuleName
"ThreadingModel"="Threading"
In the preceding registry syntax, the symbols in italic are placeholders for names and globally unique identifiers (GUIDs) that are specific to the DSP plug-in. The following table describes those placeholders.
| Placeholder | Description |
|---|---|
| PluginClsid | A GUID that is the class identifier for the DSP plug-in's primary class. This is the class that implements IMediaObject, IPluginEnable, and possibly ISpecifyPropertyPages. In a dual-mode plug-in, this class also implements IMFTransform and IMFGetService.This GUID must be in registry format, complete with the curly braces. Format: {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} |
| PluginClassFriendlyName | A friendly name for the DSP plug-in's primary class.Example: "ProsewareDSP Class" |
| PluginModuleName | The fully qualified path to the DLL that implements the DSP plug-in.Example: "C:\Program Files\Proseware\ProsewareDsp.dll" |
| Threading | A string that specifies the threading model for the plug-in. If the plug-in is going to run with Windows Media Player 11 on Windows Vista, this registry entry must be equal to "Both". If the plug-in is going to run on Windows XP or older operating systems, this registry entry can be equal to either "Apartment" or "Both". |
If your DSP plug-in implements a custom interface and if your plug-in is going to run in Windows Media Player 11 on Windows Vista, you must create the following registry subkeys and entries on the user's computer.
[HKEY_CLASSES_ROOT\CLSID\ProxyStubClsid]
@=PSFactoryBuffer
[HKEY_CLASSES_ROOT\CLSID\ProxyStubClsid\InprocServer32]
@=ProxyStubModuleName
"ThreadingModel"="Apartment"
[HKEY_CLASSES_ROOT\Interfaces\CustomInterfaceId]
@=CustomInterfaceName
[HKEY_CLASSES_ROOT\Interfaces\CustomInterfaceId\NumMethods]
@=NumberOfMethods
[HKEY_CLASSES_ROOT\Interfaces\CustomInterfaceId\ProxyStubClsid32]
@=ProxyStubClsid
In the preceding registry syntax, the symbols in italic are placeholders for names, numeric values, and globally unique identifiers (GUIDs) that are specific to the DSP plug-in. The following table describes those placeholders.
| Placeholder | Description |
|---|---|
| ProxyStubClsid | A GUID that is the class identifier for the class that implements the proxies and stubs for the DSP plug-in's custom interfaces.This GUID must be in registry format, complete with the curly braces. Format: {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} |
| ProxyStubModuleName | The fully qualified path to the DLL that implements the proxy and stub interfaces for the DSP plug-in.Example: "C:\Program Files\Proseware\ProsewareDspPS.dll" |
| CustomInterfaceId | A GUID that is the interface identifier for a custom interface that is implemented by the DSP plug-in.This GUID must be in registry format, complete with the curly braces. Format: {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} |
| CustomInterfaceName | The name of a custom interface that is implemented by the DSP plug-in.Example: "IProsewareDsp" |
| NumberOfMethods | The number of methods, including inherited methods, defined by a custom interface.Example: "5" |
If your DSP plug-in provides a property page, you must create the following registry subkeys and entries on the user's computer.
[HKEY_CLASSES_ROOT\CLSID\PropPageClsid]
@=PropPageClassFriendlyName
[HKEY_CLASSES_ROOT\CLSID\PropPageClsid\InprocServer32]
@=PluginModuleName
"ThreadingModel"="Apartment"
In the preceding registry syntax, the symbols in italic are placeholders for names and globally unique identifiers (GUIDs) that are specific to the DSP plug-in. The following table describes those placeholders.
| Placeholder | Description |
|---|---|
| PropPageClsid | A GUID that is the class identifier for the property page class provided by the DSP plug-in.This GUID must be in registry format, complete with the curly braces. Format: {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} |
| PropPageClassFriendlyName | A friendly name for the property page class.Example: "ProsewareDSP Property Page Class" |
| PluginModuleName | The fully qualified path to the DLL that implements the DSP plug-in.Example: "C:\Program Files\Proseware\ProsewareDsp.dll" |
Calling IWMPPluginRegistrar
In addition to the registry subkeys and entries described in the preceding lists and tables, you must create some registry keys and entries by calling IWMPMediaPluginRegistrar::WMPRegisterPlayerPlugin. This method performs the necessary registration to enable Windows Media Player to recognize your plug-in and present it as an option to the user.
Call IWMPMediaPluginRegistrar::WMPRegisterPlayerPlugin in your plug-in's DllRegisterServer function, and call IWMPMediaPluginRegistrar::WMPUnRegisterPlayerPlugin in your plug-in's DllUnregisterServer function. To get a pointer to an IWMPMediaPluginRegistrar interface, call CoCreateInstance, passing CLSID_WMPMediaPluginRegistrar as the Class ID. The constant CLSID_WMPMediaPluginRegistrar is defined in wmpservices.h.
Registration in the DSP Plug-in Wizard
The DSP plug-in wizard, which is included in the Windows SDK, generates sample code that is based on Active Template Library (ATL). The sample plug-in's DllRegisterServer function calls ATL's RegisterServer function, which creates registry subkeys and entries according to two registry script files in the Visual Studio project. The file ProjectName.rgs contains the script for registering the plug-in's main class, and the file ProjectName PropPage.rgs contains the script for registering the plug-in's property page class. The sample plug-in's DllRegisterServer function also calls IWMPPluginRegistrar::WMPRegisterPlayerPlugin.
The DSP plug-in wizard also generates code for a proxy-stub component that is a self-registering .dll file. The registration code for that file is in dlldata.cpp. The macro DLLDATA_ROUTINES expands to include an implementation of DllRegisterServer.