The IMediaPropertyBag interface is an interface that is exposed on filters that need to record copyright information. The interface inherits from the IPropertyBag interface and supports its Read and Write methods for properties. It includes one additional method, EnumProperty, which retrieves or sets a property and value pair.
Further documentation on the IMediaPropertyBag interface can be found in the COM documentation of the Platform SDK.
When to Implement
Implement this interface on filters that wish to expose copy right information.
When to Use
Applications use this interface to copyright the stream name of a multimedia file.
Methods in Vtable Order
| IUnknown methods | Description |
| QueryInterface | Retrieves pointers to supported interfaces. |
| AddRef | Increments the reference count. |
| Release | Decrements the reference count. |
| IMediaPropertyBag methods | Description |
| EnumProperty | Retrieves or sets a property and value pair. |
Retrieves or sets a property and value pair.
HRESULT EnumProperty(
ULONG iProperty,
VARIANT * pvarPropertyName,
VARIANT * pvarPropertyValue );
This method returns HRESULT_FROM_WIN32(ERROR_NO_MORE_ITEMS) if the iProperty parameter is larger than the number of properties there are (iProperty is zero-based). Otherwise, it will return an HRESULT value that depends on the implementation of the interface.
The pvarPropertyName parameter is always a string; the caller should set the variant type to VT_EMPTY or VT_BSTR before calling this function. PropertyValue can be any variant; the caller should set the variant type to VT_EMPTY or what is expected.
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