Microsoft DirectX 9.0


The GetPreroll method retrieves the amount of data that will be queued before the start position.


HRESULT GetPreroll(
  LONGLONG *pllPreroll



[out] Pointer to a variable that receives the preroll time, in units of the current time format.

Return Value

Returns an HRESULT value. Possible values include the following.

Value Description
S_OK Success.
E_NOTIMPL Method is not supported.
E_POINTER NULL pointer argument.


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.

See Also