There is a separate LVREC and ENCO on 600D.
NSTUB(0xFF10D1D0, str:[LVREC]MVR_[LVREC]GMT_MVR)
NSTUB(0xFF10D464, str:Gmt\GmtMovieState.c_[GMT][LVREC]_gmtRecStart)
NSTUB(0xFF10D758, str:[GMT][LVREC]_gmtEncodeStopMotion)
Seems separate from the MVR. Does it make the LV image? Separate recorder/encoder of some sort? PTP?