METHOD AND APPARATUS FOR ENCODING AND DECODING MOTION VECTOR

摘要

The present invention relates to a method for encoding and decoding a motion vector and an apparatus for encoding and decoding a motion vector, wherein the method for encoding and decoding a motion vector comprises the steps of: selecting a candidate motion vector set for a current motion vector, selecting a prediction motion vector from the candidate motion vector set, and judging whether or not the prediction motion vector is predictable in a decoding apparatus. If the prediction motion vector is predictable, the current motion vector is encoded using a motion vector prediction mode that indicates a prediction motion vector and prediction possibility. If the prediction motion vector is not predictable, the current vector is encoded using a motion vector prediction mode that indicates a default prediction motion vector and prediction impossibility. According to the present invention, the method and the apparatus can provide information for searching for the prediction motion vector and share a certain function for the search without directly notifying the prediction motion vector for the current motion vector to the decoding apparatus so that the current motion vector may be encoded and/or decoded by selecting the prediction motion vector according to the motion vector prediction mode, and the motion vector prediction mode may be transmitted to the decoding apparatus. Therefore, the amount of encoded bits can be reduced and the performances of the motion vector prediction and compensation can be improved. [Reference numerals] (AA) Begin encoding a motion vector; (BB) End encoding the motion vector; (S500) Select a candidate motion vector set; (S502) Select a prediction motion vector from the candidate motion vector set; (S504) Is the prediction motion vector predictable in a decoding apparatus?; (S506) Encode the current motion vector using a motion vector prediction mode that indicates a prediction motion vector and prediction possibility (a first encoding); (S508) Encode the current motion vector using a motion vector prediction mode that indicates a default prediction motion vector and prediction impossibility (a second encoding)