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ILMDVRSink::SetOffsetToReach

Summary

Indicate the DVR sink object to set the offset reached event when it writes data past a certain offset.

Syntax

#include "ILMDVRSink.h"

Language	Syntax
C	HRESULT ILMDVRSink_SetOffsetToReach(pILMDVRSink, nRegistrationID, Offset)
C++	HRESULT SetOffsetToReach(nRegistrationID, Offset)

Parameters

ILMDVRSink *pILMDVRSink

Pointer to an ILMDVRSink interface.

long nRegistrationID

The unique identifier used to create the offset reached event.

double Offset

The target offset.

Returns

Value	Meaning
S_OK	The function was successful.
E_INVALIDARG	The registration ID or the offset are invalid.
<>S_OK	An error occurred. Refer to the Error Codes or the HRESULT error codes in the DirectShow documentation.

Comments

Use this method to instruct the DVR sink object to set the offset reached event once it has written data past a certain offset. This method is used internally by the DVR source object.

For example, if an application wants to read N bytes from offset X, then it will do the following:

Reset the offset reached event
Call SetOffsetToReach(X + N)
Use a windows waiting function and wait for the offset reached event to be set. (This of course, assumes the event was created through an earlier call to ILMDVRSink::CreateEvents2.

The offset must be > 0 and it indicates the offset of the first byte that is not needed. So, the byte at offset 'Offset -1' will be present in the DVR buffer, but the byte at offset 'Offset' might not be written yet.