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

   
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