Encoder, decoder and bitstream for video with frames with global motion

A non-transitory computer-readable recording medium storing an encoded bitstream which is decodable by a decoding method, the method comprising:

• receiving a bit stream, the bitstream including a coded picture including a first region comprising a first contiguous plurality of coded blocks, a second region comprising a second contiguous plurality of coded blocks wherein a block in the second region is intra-predicted, and signaling information associated with each coded block;
• for each coded block in the first region, in response to the associated signaling information, construct a motion vector candidate list including at least one motion vector candidate for enabling the reconstruction of global motion in the first region, the one motion vector candidate comprising multiple control point motion vectors for 4-parameter or 6-parameter affine motion compensation;
• decoding each block in the first region using affine motion compensation to reconstruct global motion in the first region;
• and
• decoding the intra-predicted block;
• decoding the coded blocks of the second region, including the intra-predicted block, without using a motion vector candidate in a motion vector candidate list that enables reconstruction of global motion, whereby only local motion is reconstructed in the second region.

A video decoder having circuitry configured to:

• receive a bit stream, the bitstream including a coded picture including a first region comprising a first contiguous plurality of coded blocks, a second region comprising a second contiguous plurality of coded blocks wherein a block in the second region is intra-predicted, and signaling information associated with each coded block;
• for each coded block in the first region, in response to the associated signaling information, construct a motion vector candidate list including at least one motion vector candidate for enabling the reconstruction of global motion in the first region, the one motion vector candidate comprising multiple control point motion vectors for 4-parameter or 6-parameter affine motion compensation;
• decode each block in the first region using affine motion compensation to reconstruct global motion in the first region;
• and
• decode the intra-predicted block;
• decode the coded blocks of the second region, including the intra-predicted block, without using a motion vector candidate in a motion vector candidate list that enables reconstruction of global motion, whereby only local motion is reconstructed in the second region.