Patent attributes
Techniques and tools are described for decoding video data having extended range motion vectors. For example, a sequence level syntax element (such as a flag in a header) indicates whether one or more picture level syntax elements are present for one or more frames of the sequence. If so, then a picture level syntax element for a current frame is processed. The picture level syntax element indicates a motion vector range for the current frame, where the motion vector range may be a default range or one of multiple available extended ranges. Additionally, a signed modulus operation by a factor that depends on the motion vector range may be performed when reconstructing the horizontal and vertical motion vector components to assure that the motion vectors are within the motion vector range.
