About the Media Type GUID Definition (deprecated)
This page documents a feature that may be unavailable in future versions of Windows Media Player and the Windows Media Player SDK.
The very first code you'll probably need to modify is the definition of the GUID that represents your media type. Each time you generate a new sample rendering plug-in project using the Windows Media Player Plug-in Wizard, the wizard creates a new GUID for the project media type. You are certainly free to use this GUID for creating your content, but if you have already done that you'll need to change the GUID in the plug-in.
The media type GUID definition can be found in the header file having the same name as the plug-in project. For example, if you named the project MyRenderingPlugin, then the header file you need to change is named MyRenderingPlugin.h. When you view the file contents in Visual Studio, you'll see the GUID definition near the top of the file after the last #include statement. It looks like this:
DEFINE_GUID(MEDIATYPE_MYRENDERINGPLUGIN, 0xc1ccdf59, 0x6924, 0x4b96, 0x82, 0x47, 0xdb, 0xb0, 0xea, 0xe5, 0xb6, 0x7);
Note The GUID shown here is the media type identifier for the sample rendering file provided with this SDK. The GUID in your project will be different and unique.
If you already have a GUID for your media type, you must replace the provided GUID definition with your own. Be sure to use the DEFINE_GUID format like the sample code does.