IWMHeaderInfo3 interface

The IWMHeaderInfo3 interface supports the following new metadata features:

  • Attribute data in excess of 64 kilobytes.
  • Multiple attributes with the same name.
  • Attributes in multiple languages.
Because the attributes created using this interface can have duplicate names, the methods of this interface use index values to identify attributes.

The IWMHeaderInfo3 interface is implemented by the metadata editor object, the writer object, the reader object, and the synchronous reader object. To obtain a pointer to an instance, call the QueryInterface method of any other interface in the desired object.


The IWMHeaderInfo3 interface has these methods.

Method Description
IWMHeaderInfo3::AddAttribute The AddAttribute method adds a metadata attribute. To change the value of an existing attribute, use the IWMHeaderInfo3::ModifyAttribute method.
IWMHeaderInfo3::AddCodecInfo The AddCodecInfo method adds codec information to a file. When you copy a compressed stream from one file to another, use this method to include the information about the encoding codec in the file header.
IWMHeaderInfo3::DeleteAttribute The DeleteAttribute method removes an attribute from the file header.
IWMHeaderInfo3::GetAttributeByIndexEx The GetAttributeByIndexEx method retrieves the value of an attribute specified by the attribute index.
IWMHeaderInfo3::GetAttributeCountEx The GetAttributeCountEx method retrieves the total number of attributes associated with a specified stream number.
IWMHeaderInfo3::GetAttributeIndices The GetAttributeIndices method retrieves a list of valid attribute indices within specified parameters.
IWMHeaderInfo3::ModifyAttribute The ModifyAttribute method modifies the settings of an existing attribute.


For information about using the writer for metadata editing, see To Edit Metadata with the Writer.


Target Platform Windows
Header wmsdkidl.h

See also

IWMHeaderInfo Interface

IWMHeaderInfo2 Interface


Metadata Editor Object

Reader Object

Synchronous Reader Object

Writer Object