Virtual temporal affine candidates

An apparatus for encoding a video block, comprising:

• a processor, configured to:
• determine, for a video block being encoded in a picture, at least one predictor candidate;
• determine for the at least one predictor candidate, one or more corresponding control point motion vectors, based on motion information associated to the at least one predictor candidate;
• determine for the video block being encoded, one or more corresponding control point motion vectors, based on neighboring sub-blocks surrounding corner sub-blocks of the video block, wherein said neighboring sub-blocks surrounding corner sub-blocks are searched in an order to determine a first neighboring sub-block having a motion vector and using that as a predictor candidate for the corresponding corner;
• rescaling the one or more control point motion vectors based on the reference index of both a current and a reference frame;
• determining, based on the one or more resealed corresponding control point motion vectors determined for the video block, a corresponding motion field, wherein the corresponding motion field identifies motion vectors used for prediction of sub-blocks of the video block being encoded;
• and,
• encode the video block based on the corresponding motion field, wherein picture order count for said motion field is chosen as the first available candidate among the neighboring sub-blocks.

A method, comprising:

• determining, for a video block being decoded in a picture, at least one predictor candidate;
• determining for the at least one predictor candidate, one or more corresponding control point motion vectors, based on motion information associated to the at least one predictor candidate;
• determining for the video block being decoded, one or more corresponding control point motion vectors, based on neighboring sub-blocks surrounding corner sub-blocks of the video block, wherein said neighboring sub-blocks surrounding corner sub-blocks are searched in an order to determine a first neighboring sub-block having a motion vector and using that as a predictor candidate for the corresponding corner;
• rescaling the one or more control point motion vectors based on the reference index of both a current and a reference frame;
• determining, based on the one or more resealed corresponding control point motion vectors determined for the video block, a corresponding motion field, wherein the corresponding motion field identifies motion vectors used for prediction of sub-blocks of the video block being decoded;
• and,
• decoding the video block based on the corresponding motion field, wherein picture order count for said motion field is chosen as the first available candidate among the neighboring sub-blocks.

An apparatus for decoding a video block, comprising:

• a processor, configured to:
• determine, for a video block being decoded in a picture, at least one predictor candidate;
• determine for the at least one predictor candidate, one or more corresponding control point motion vectors, based on motion information associated to the at least one predictor candidate;
• determine for the video block being decoded, one or more corresponding control point motion vectors, based on neighboring sub-blocks surrounding corner sub-blocks of the video block, wherein said neighboring sub-blocks surrounding corner sub-blocks are searched in an order to determine a first neighboring sub-block having a motion vector and using that as a predictor candidate for the corresponding corner;
• rescaling the one or more control point motion vectors based on the reference index of both a current and a reference frame;
• determining, based on the one or more rescaled corresponding control point motion vectors determined for the video block, a corresponding motion field, wherein the corresponding motion field identifies motion vectors used for prediction of sub-blocks of the video block being decoded;
• and,
• decode the video block based on the corresponding motion field, wherein picture order count for said motion field is chosen as the first available candidate among the neighboring sub-blocks.