Decoding a current block of a current frame includes obtaining motion trajectories between the current frame and at least one previously coded frame by projecting motion vectors from the at least one previously coded frame onto the current frame. A motion field is obtained between the current frame and a reference frame used for coding the current frame. The motion field is obtained by extending the motion trajectories from the current frame towards the reference frame. A motion vector for the current block is identified based on the motion field. A prediction block is obtained for the current block using a reference block of the reference frame identified using the motion vector.