MF_TOPOSTATUS enumeration (mfapi.h)

Specifies the status of a topology during playback.

Syntax

typedef enum {
  MF_TOPOSTATUS_INVALID = 0,
  MF_TOPOSTATUS_READY = 100,
  MF_TOPOSTATUS_STARTED_SOURCE = 200,
  MF_TOPOSTATUS_DYNAMIC_CHANGED = 210,
  MF_TOPOSTATUS_SINK_SWITCHED = 300,
  MF_TOPOSTATUS_ENDED = 400
} MF_TOPOSTATUS;

Constants

MF_TOPOSTATUS_INVALID Value: 0 This value is not used.
MF_TOPOSTATUS_READY Value: 100 The topology is ready to start. After this status flag is received, you can use the Media Session's IMFGetService::GetService method to query the topology for services, such as rate control.
MF_TOPOSTATUS_STARTED_SOURCE Value: 200 The Media Session has started to read data from the media sources in the topology.
MF_TOPOSTATUS_DYNAMIC_CHANGED Value: 210 The Media Session modified the topology, because the format of a stream changed.
MF_TOPOSTATUS_SINK_SWITCHED Value: 300 The media sinks have switched from the previous topology to this topology. This status value is not sent for the first topology that is played. For the first topology, the MESessionStarted event indicates that the media sinks have started receiving data.
MF_TOPOSTATUS_ENDED Value: 400 Playback of this topology is complete. The Media Session might still use the topology internally. The Media Session does not completely release the topology until it sends the next MF_TOPOSTATUS_STARTED_SOURCE status event or the MESessionEnded event.

Remarks

This enumeration is used with the MESessionTopologyStatus event. The MESessionTopologyStatus event always has an MF_EVENT_TOPOLOGY_STATUS attribute whose value is a member of this enumeration.

For a single topology, the Media Session sends these status flags in numerical order, starting with MF_TOPOSTATUS_READY. However, there is no guarantee about the ordering of the events across two different topologies. For example, you might get MF_TOPOSTATUS_READY for a topology before you get MF_TOPOSTATUS_ENDED for the previous topology.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2008 [desktop apps only]
Header	mfapi.h

See also

MESessionTopologyStatus

Media Foundation Enumerations