LOOPEDSTREAMING_POSITION_EVENT_DATA structure (ksmedia.h)

The LOOPEDSTREAMING_POSITION_EVENT_DATA structure describes a position event in a looped buffer.

Syntax

typedef struct {
  KSEVENTDATA KsEventData;
#if ...
  ULONGLONG   Position;
#else
  DWORDLONG   Position;
#endif
} LOOPEDSTREAMING_POSITION_EVENT_DATA, *PLOOPEDSTREAMING_POSITION_EVENT_DATA;

Members

KsEventData

Specifies the type of notification that the system will send to the client when the event occurs. For more information, see KSEVENTDATA.

Position

Specifies the buffer position as a byte offset from the beginning of the looped buffer. If the size of the buffer is n bytes, the Position member must contain a value in the range 0 to n-1.

Remarks

The KSEVENT_LOOPEDSTREAMING_POSITION event uses the LOOPEDSTREAMING_POSITION_EVENT_DATA structure. This type of event occurs only in looped buffers. A looped buffer is a data buffer for an audio stream of type KSINTERFACE_STANDARD_LOOPED_STREAMING.

The driver (typically a system component) that generates the event compares the byte offset in the Position member to the play cursor (in a rendering stream) or the record cursor (in a capture stream). The position event occurs when the play or record cursor passes through the specified position.

When the play or record cursor reaches the end of a looped buffer, the cursor wraps around to the beginning of the buffer, which corresponds to a byte offset of 0.

For more information about looped buffers, buffer positions, and play and record cursors, see Audio Position Property.

Requirements

See also

KSEVENTDATA

KSEVENTSET_LoopedStreaming

KSEVENT_LOOPEDSTREAMING_POSITION

KSINTERFACE_STANDARD_LOOPED_STREAMING