Contains the sample description box for an MP4 or 3GP file.

Data type



To get this attribute, call IMFAttributes::GetBlob.

To set this attribute, call IMFAttributes::SetBlob.

Applies to



The sample description box describes the encoding used for a stream in the file.

The MPEG-4 file source sets this attribute on the media type for each stream. The value of the attribute is the raw data in the sample description box. If the MPEG-4 file source can parse the sample description, it also adds the format details to the media type. Otherwise, the application or the decoder must parse the sample description from the MF_MT_MPEG4_SAMPLE_DESCRIPTION attribute.

When setting this attribute on MPEG-4 sink through IMFMediaTypeHandler::SetCurrentMediaType method, the data for the attribute MF_MT_MPEG4_SAMPLE_DESCRIPTION should not change after one or more samples have been sent to the sink on the corresponding stream's IMFStreamSink::ProcessSample interface.

The GUID constant for this attribute is exported from mfuuid.lib.


Requirement Value
Minimum supported client
Windows 7 [desktop apps | UWP apps]
Minimum supported server
Windows Server 2008 R2 [desktop apps | UWP apps]

See also

Alphabetical List of Media Foundation Attributes

Media Type Attributes