please take a look on comments provided by our experts:
There is implicit requirement for DataReader when it operates with live streams: GetSize() should return 0. This prevents MPEG2TSParser from calling SetPostion.
GetPosition doesnt return UMC::Status, it returns Ipp64u-value that is current position in the stream. Correctness of this value isnt required for live streaming.
there is recomendation from our expert to check implementation of MovePosition(Ipp64u) function in your StreamReader. It should have similar behaviour as in DataReader. This function is used by TS parser.