[MPlayer-users] how to set the size of the buffer when recording tv input

when recording tv input if proccesing reaches a 100 % mencoder seems to store the stream in a buffer (type thing) han takes it later when the load lessen. how to reducethe size of this so the buffer does not fill up my ram and crash (more or less) the computer. or maybe is there an option like -framedrop in mencoder.