Contains a list of RFC 1766 languages used in the current presentation.

Data type



To get this attribute, call IMFAttributes::GetBlob.

To set this attribute, call IMFAttributes::SetBlob.

Applies to



This attribute applies to presentation descriptors that were generated from the ASF ContentInfo Object by a call to IMFASFContentInfo::GeneratePresentationDescriptor. The format of the byte array is as follows:

Language List Object fieldData typeSizeDescription
Language ID Records CountDWORD4 bytesNumber of languages
Language ID RecordsBYTE[]VariesArray of language strings (see below).


The first DWORD is the number of languages, followed by an array of language identifier strings. Each string has the following format:

Language List Object fieldData typeSizeDescription
Language ID LengthDWORD4 bytesThe length of the string in bytes, including the size of the trailing NULL character.
Language IDWCHAR[]VariesA null-terminated string containing the RFC 1766 language name.


Each string is a language tag compliant with RFC 1766.

Use this attribute only for backward compatibility with the enumeration order of the IWMReaderAdvanced4 interface in the Windows Media Format SDK. The language strings are stored in a different order in the MF_PD_ASF_LANGLIST attribute.


Minimum supported client

Windows 7 [desktop apps only]

Minimum supported server

Windows Server 2008 R2 [desktop apps only]



See also

Alphabetical List of Media Foundation Attributes
Presentation Descriptor Attributes