MEQualityNotify event

Provides feedback to the quality manager about playback quality.

Event values

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

VARTYPE Description
See Remarks.


This event is raised by some pipeline components. The Media Session forwards the event to the quality manager by calling the IMFQualityManager::NotifyQualityEvent method.

The event's extended type indicates the meaning of the event data.

Extended type Event data
MF_QUALITY_NOTIFY_PROCESSING_LATENCY Approximate processing latency introduced by the component, in 100-nanosecond units.
Processing latency is the amount of latency that a component introduces into the pipeline by processing a sample. In some cases, the latency cannot be derived simply by looking at the calls to IMFQualityManager::NotifyProcessInput and IMFQualityManager::NotifyProcessOutput. For example, there may not be a one-to-one correspondence between input samples and output samples. In this case, the component might send an MEQualityNotify event with the processing latency. If the processing latency changes, the component can send a new event at any time during streaming.
MF_QUALITY_NOTIFY_SAMPLE_LAG Lag time for the sample, in 100-nanosecond units. If the value is positive, the sample was late. If the value is negative, the sample was early.


To get the extended type, call IMFMediaEvent::GetExtendedType.

Pipeline components are not required to send this event.


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