MEUpdatedStream event

Raised by a media source when it restarts or seeks a stream that is already active.

When the IMFMediaSource::Start method is called on a media source, the media source sends one event for each selected stream:

  • The source sends the MENewStream event if the stream was not selected in the previous call to Start, or this is the very first call to Start on this media source.

  • The source sends the MEUpdatedStream event if the stream was already selected in the previous call to Start.

No events are sent for unselected streams.

Event values

Possible values retrieved from IMFMediaEvent::GetValue include the following.

VARTYPE Description
Pointer to the stream's IMFMediaStream interface.


On the first call to Start in which a stream becomes active, the media source sends an MENewStream event for the stream. On subsequent calls to Start, the media source sends an MEUpdatedStream event, until the stream is deselected.


Requirement Value
Minimum supported client
Windows Vista [desktop apps only]
Minimum supported server
Windows Server 2008 [desktop apps only]
Mfobjects.h (include Mfidl.h)

See also

Media Foundation Events