1. A method for decoding an encoded bit stream for a picture in a video decoder, the method comprising: decoding a merge flag for a non skip mode inter-predicted prediction unit (PU) from the encoded bit stream; constructing a merge mode motion data vector (merging candidate) list for the non skip mode inter-predicted PU for a first value of the merge flag; adding a zero motion vector merging candidate to the merging candidate list comprising determining a content of the zero motion vector merging candidate based on a prediction type of a slice containing the non skip mode inter-predicted PU wherein the zero motion vector merging candidate comprises a motion vector with a value of zero if the slice is a forward predicted slice, and the zero motion vector merging candidate comprises two motion vectors with values of zero if the slice is a bi-directionally predicted slice ; and reconstructing the non skip mode inter-predicted PU based on the merging candidate list.