PFNKSCORRELATEDTIME callback function (ks.h)

Article
03/15/2022

A streaming minidriver's KStrCorrelatedTime routine is called to retrieve both the presentation time and physical time in a correlated manner. This allows the clock owner to completely determine the current time.

Syntax

PFNKSCORRELATEDTIME Pfnkscorrelatedtime;

LONGLONG Pfnkscorrelatedtime(
  [in]  PVOID Context,
  [out] PLONGLONG SystemTime
)
{...}

Parameters

[in] Context

Pointer to the minidriver-supplied information context. The minidriver passes the information context to KsAllocateDefaultClockEx in the function's DeferredContext parameter when the minidriver allocates a custom DPC timer object.

[out] SystemTime

Specifies a pointer to a variable that receives the performance counter frequency.

Return value

Returns the value of the performance counter in units of ticks.

Remarks

Typically, if a minidriver supplies a KStrCorrelatedTime callback function, the minidriver must also supply KStrSetTimer and KStrCancelTimer callback functions.

The minidriver-supplied KStrCorrelatedTimer must have the same characteristics as KeQueryPerformanceCounter.

Requirements

Requirement	Value
Target Platform	Desktop
Header	ks.h (include Ks.h)