| 摘要 |
A method of deriving motion vectors for a bi-predictive block in direct mode is disclosed, the method comprising: obtaining a reference picture list for the bi-predictive block, the reference picture list including short-term reference pictures and long-term reference pictures; obtaining a reference index information associated with a reference picture of the bi-predictive block; obtaining a reference picture in the reference picture list by using the reference index information; determining motion vectors of the bi-predictive block based on a type of the obtained reference picture; and decoding the bi-predictive image block based on the determined motion vectors; wherein the determining step sets a first motion vector of the bi-predictive image block equal to a motion vector of a co-located image block if the reference picture is a long-term reference picture, and wherein the determining step sets a second motion vector of the bi-predictive image block equal to zero if the reference picture is a long-term reference picture. |
