Global motion models for motion vector inter prediction
A decoder is configured to receive a bit stream including a current frame and a picture header associated with the entire current frame, determine, as a function of the picture header, that one global motion mode is enabled for the entire current frame, the enabled global motion mode being selected from a group including translational motion, 4-parameter affine motion, and 6-parameter affine motion, detect, based on the enabled global motion mode, a plurality of parameters applicable to the entire frame, and decode the current frame using the detected parameters.
1. A decoder, the decoder comprising circuitry configured to:
receive a coded bitstream including a Sequence Parameter Set and a sequence of coded pictures, wherein the Sequence Parameter Set allows three global motion modes for a sequence of coded pictures, and wherein the three global motion modes include translational motion, 4-parameter affine motion, and 6-parameter affine motion;
detect in the Sequence Parameter Set that only translational global motion model is enabled, and that the affine global motion modes are disabled for the sequence of coded pictures;
decode one coded picture in the sequence by decoding a global motion region in the picture using translational motion, the global motion region in the picture comprising multiple 128×128 coding units.
2. The decoder of claim 1 , wherein the header includes a picture parameter set (PPS).
3. The decoder of claim 1 , wherein the header includes a sequence parameter set (SPS).
4. The decoder of claim 1 , wherein each current block is a coding tree unit.
5. A method comprising:
receiving, by a decoder, a coded bitstream including a Sequence Parameter Set and a sequence of coded pictures, wherein the Sequence Parameter Set allows three global motion modes for a sequence of coded pictures, and wherein the three global motion modes include translational motion, 4-parameter affine motion, and 6-parameter affine motion;
detecting in the Sequence Parameter Set that only translational global motion model is enabled, and that the affine global motion modes are disabled for the sequence of coded pictures;
decoding one coded picture in said sequence by decoding a global motion region in the one picture using translational motion, the global motion region in the picture comprising multiple 128×128 coding units.
6. The method of claim 5 , wherein the header includes a picture parameter set (PPS).
7. The method of claim 5 , wherein the header includes a sequence parameter set (SPS).
8. The method of claim 5 , wherein each current block is a coding tree unit.