MESourceStarted event
Raised when a media source starts without seeking.
Event values
Possible values retrieved from IMFMediaEvent::GetValue include the following.
| VARTYPE | Description |
|---|---|
| VT_EMPTY |
No event data. The start time was from the current position. |
| VT_I8 |
The starting time, in 100-nanosecond units, relative to the time stamps on the samples. |
Attributes
The following attributes are defined for this event.
| Attribute | Description |
|---|---|
| MF_EVENT_SOURCE_ACTUAL_START |
Start time. The media source sets this attribute if it restarts from its current position. |
| MF_EVENT_SOURCE_FAKE_START |
Specifies whether the current segment topology is empty. The sequencer source sets this attribute. |
| MF_EVENT_SOURCE_PROJECTSTART |
Start time for a segment, relative to the start of the presentation. The sequencer source sets this attribute. |
Remarks
A media source raises this event when it starts from a stopped state, or starts from a paused state at the same position in the source. The event is raised if the IMFMediaSource::Start method returns S_OK.
If the media source starts from the current position and the source's previous state was running or paused, the event data can empty (VT_EMPTY). If the event data is VT_EMPTY, the media source might set the MF_EVENT_SOURCE_ACTUAL_START attribute with the actual starting time.
If the media source starts from a new position, or the source's previous state was stopped, the event data must be the starting time (VT_I8).
If the Start method causes a seek, the media source sends the MESourceSeeked event instead of MESourceStarted.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows Vista [desktop apps only] |
| Minimum supported server |
Windows Server 2008 [desktop apps only] |
| Header |
|
See also