IAMStreamControl::StartAt

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Windows Embedded CE 6.0 R3

4/8/2010

This method informs the pin when to start sending streaming data.

Syntax

HRESULT StartAt(
  const REFERENCE_TIME* ptStart,
  DWORD dwCookie
);

Parameters

• ptStart
  [in] Time at which to start streaming as specified in the REFERENCE_TIME structure. If NULL, start immediately (no notification); if MAX_TIME, start canceled and will have no effect.

• dwCookie
  [in] Specifies a particular value to be sent with the notification when the start occurs. (Only used if ptStart is non-NULL or MAX_TIME).

Return Value

Returns an HRESULT value that depends on the implementation of the interface.

Remarks

Streams are enabled by default, so this method will have no effect unless a previous StopAt member function has been called.

If the pointer to the REFERENCE_TIME is not NULL or MAX_TIME, then pins should signal EC_STREAM_CONTROL_STARTED with an IPin pointer and the cookie specified in the dwCookie parameter. This enables applications to tie the events back to their requests. If the ptStart pointer is NULL or MAX_TIME, then the filter graph sends no event.

If start and stop are scheduled for a single point in time, the effect is as if the start occurred an infinitesimal time before the stop. You can use this to capture a single frame.

Requirements