| 摘要 |
A video coding method for deriving motion vectors for a bi-predictive block in direct mode is disclosed, the method comprising: obtaining a reference index information associated with a reference picture of the bi-predictive block; obtaining a reference picture by using the reference index information; determining motion vectors of the bi-predictive block; and decoding the bi-predictive block based on the determined motion vectors. The method further comprises determining a kind of the reference picture pointed to by a motion vector of a co-located block, the kind of the reference picture including a long-term reference picture and a short-term reference picture. In determining motion vectors of block a forward motion vector of the bi-predictive block is set equal to the motion vector of the co-located block, if the kind of the reference picture is a long-term reference picture, and in determining motion vectors of the bi-predictive block a backward motion vector of the bi-predictive block is set equal to zero, if the kind of the reference picture is the long-term reference picture. |
