Adaptive Resolution for Motion Vector Difference

A method for decoding an inter-predicted video block of a video stream, comprising:

• receiving the video stream;
• determining that a motion vector difference (MVD) between a motion vector and a reference motion vector associated with the inter-predicted video block is signaled in the video stream, wherein the reference motion vector corresponds to a reference picture in only one of reference frame list 0 and reference frame list 1 unless the MVD is jointly signaled for two reference pictures;
• extracting, from the video stream, an integer portion of magnitude of the MVD;
• and
• determining a pixel resolution for the MVD according to the integer portion of the magnitude of the MVD;
• identifying additional MVD information in the video stream based on the pixel resolution;
• and
• decoding the inter-predicted video block based on the pixel resolution, the integer portion of the magnitude of the MVD, the additional MVD information, the reference motion vector, and a reference frame associated with the motion vector.

An electronic device for decoding an inter-predicted video block of a video stream, the electronic device comprising a memory for storing computer instructions and a processor in communication with the memory, wherein the processor, when executing the computer instructions, is configured to cause the electronic device to:

• receive the video stream;
• determine that a motion vector difference (MVD) between a motion vector and a reference motion vector associated with the inter-predicted video block is signaled in the video stream, wherein the reference motion vector corresponds to a reference picture in only one of reference frame list 0 and reference frame list 1 unless the MVD is jointly signaled for two reference pictures;
• obtain, from the video stream, an indication of a magnitude range of the MVD among a plurality of predefined magnitude ranges for motion vector differences;
• determine a pixel resolution for the MVD according to the magnitude range;
• identify additional MVD information in the video stream based on the pixel resolution;
• extract the additional MVD information from the video stream;
• and
• decode the inter-predicted video block based on the pixel resolution, the additional MVD information, the reference motion vector, and a reference frame associated with the motion vector.