tv_LayerStretch id origin displacement mode
Changes the duration of the layer with identifier id. The origin argument may be equal to "START" or "END". It identifies which end of the layer is to be displaced ("START" for the beginning and "END" for the end of the layer). The distance argument is the distance by which the chosen end is displaced along the global time-line. Note that this argument may be positive or negative. Mode arguments contains the stretch mode : "TIMESTRETCH" for a timestretching, "CUT" for a cut frames (when you reduce the size only), "LAST" for hold on last frame, "LOOP" for looping mode, "PINGPONG" for the pingpong mode, "CLEAR" creates empty frames, "FAST" is a timestretch without interpolation.