IMediaSeeking::GetPreroll
| Microsoft DirectShow 9.0 |
IMediaSeeking::GetPreroll
The GetPreroll method retrieves the amount of data that will be queued before the start position.
Syntax
HRESULT GetPreroll( LONGLONG *pllPreroll );
Parameters
pllPreroll
[out] Pointer to a variable that receives the preroll time, in units of the current time format.
Return Values
Returns an HRESULT value. Possible values include the following.
| Return code | Description |
| S_OK | Success. |
| E_NOTIMPL | Method is not supported. |
| E_POINTER | NULL pointer argument. |
Remarks
The preroll is the time prior to the start position at which nonrandom access devices, such as tape players, should start rolling.
The returned value is expressed in the current time format. The default time format is REFERENCE_TIME units (100 nanoseconds). To change time formats, use the IMediaSeeking::SetTimeFormat method.
Requirements
Header: Declared in Strmif.h; include Dshow.h.
Library: Use Strmiids.lib.
See Also