MFSampleExtension_RepeatFirstField attribute

Specifies whether to repeat the first field in an interlaced frame. This attribute applies to media samples.

Data type

BOOL stored as UINT32


To get this attribute, call IMFAttributes::GetUINT32.

To set this attribute, call IMFAttributes::SetUINT32.

Applies to



If the value is FALSE or the attribute is not set, the first field is not repeated. If the value is TRUE, the first field is repeated. The value TRUE is valid only when the following conditions are true:

  • The media type is mixed interlaced and progressive. (The MF_MT_INTERLACE_MODE attribute attribute on the media type is MFVideoInterlace_MixedInterlaceOrProgressive.)
  • The frame is progressive and the MFSampleExtension_Interlaced attribute on the sample is TRUE.
  • The MFSampleExtension_BottomFieldFirst attribute is set on the sample. The value can be TRUE or FALSE. The ordering of the fields is determined by this attribute.

This attribute is used for 3:2 pulldown. The following table shows the order in which fields are displayed.

MFSampleExtension_RepeatFirstFieldMFSampleExtension_BottomFieldFirstField order
TRUETRUELower, upper, lower
TRUEFALSEUpper, lower, upper
FALSETRUELower, upper
FALSEFALSEUpper, lower


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


Minimum supported client

Windows Vista [desktop apps | Windows Store apps]

Minimum supported server

Windows Server 2008 [desktop apps | Windows Store apps]



See also

Alphabetical List of Media Foundation Attributes
Sample Attributes
Media Samples
Video Interlacing