This example shows how you can wait for the DVR sink to write data past a certain offset. This is useful if you want to wait for the data to become available before reading it. The error checking has been omitted for clarity.
void WaitForData(ILMDVRSink* pSink, __int64 startOffset, long nBytes) { long registrationId = (long)GetTickCount(); // set this to a unique value in your application OLE_HANDLE dataWrittenEvent; OLE_HANDLE listChangedEvent; OLE_HANDLE offsetReachedEvent; // create the offset reached event pSink->CreateEvents2(registrationId, GetCurrentProcessId(), &dataWrittenEvent, &listChangedEvent, &offsetReachedEvent); // instruct the sink to set the offset reached event once it reached nBytes past offset startOffset pSink->SetOffsetToReach(registrationId, (double)(startOffset + nBytes)); // wait for the event to be set WaitForSingleObject((HANDLE)offsetReachedEvent, INFINITE); // free the events pSink->FreeEvents(registrationId); }