Method and apparatus for affine merge mode prediction for video coding system

An apparatus for Inter prediction of video coding performed by a video encoder or a video decoder that utilizes motion vector prediction (MVP) to code a motion vector (MV) associated with a block coded with coding modes including Inter and Merge modes, the apparatus comprising one or more electronic circuits or processors arranged to:

• receive input data related to a current block at a video encoder side or receive a video bitstream corresponding to compressed data including the current block at a video decoder side, wherein the current block consists of a set of pixels from video data;
• determine motion vectors associated with a set of neighbouring blocks of the current block;
• generate a unified Merge candidate list based on the motion vectors associated with the set of neighbouring blocks of the current block, wherein if the motion vector exists for a given neighbouring block belonging to the set of neighbouring blocks of the current block, the motion vector associated with the given neighbouring block is included in the unified Merge candidate list regardless of whether the given neighbouring block is coded using a regular mode or an affine mode;
• and
• if the current block is coded using the Merge mode, encode the current block at the video encoder side or decode the current block at the video decoder side using the unified Merge candidate list, wherein the current block is coded using motion information of a Merge candidate in the Unified Merge candidate list as indicated by a Merge index.

A method of Inter prediction for video coding performed by a video encoder or a video decoder that utilizes motion vector prediction (MVP) to code a motion vector (MV) associated with a block coded with coding modes including Inter and Merge modes, the method comprising:

• receiving input data related to a current block at a video encoder side or receiving a video bitstream corresponding to compressed data including the current block at a video decoder side, wherein the current block consists of a set of pixels from video data;
• deriving one or more new affine Merge candidates based on one or more reference blocks coded using an affine mode in a reference picture for the current block, based on one or more previous blocks coded using the affine mode, or based on one or more global affine parameters, wherein said one or more new affine Merge candidates are associated with affine-coded blocks and said one or more previous blocks are processed prior to the current block, and either said one or more previous blocks do not belong to neighbouring blocks of the current block or the MVs for control points of one of the neighbouring blocks of the current block are used to derive said one or more new affine Merge candidates;
• generating a Merge candidate list including said one or more new affine Merge candidate;
• and
• if the current block is coded using the Merge mode, encoding the current block at the video encoder side or decoding the current block at the video decoder side using the Merge candidate list, wherein the current block is coded using motion information of a Merge candidate in the Merge candidate list as indicated by a Merge index.

An apparatus for Inter prediction of video coding performed by a video encoder or a video decoder that utilizes motion vector prediction (MVP) to code a motion vector (MV) associated with a block coded with coding modes including Inter and Merge modes, the apparatus comprising one or more electronic circuits or processors arranged to:

• receive input data related to a current block at a video encoder side or receive a video bitstream corresponding to compressed data including the current block at a video decoder side, wherein the current block consists of a set of pixels from video data;
• derive one or more new affine Merge candidates based on one or more reference blocks coded using an affine mode in a reference picture for the current block, based on one or more previous blocks coded using the affine mode, or based on one or more global affine parameters, wherein said one or more new affine Merge candidates are associated with affine-coded blocks and said one or more previous blocks are processed prior to the current block, and either said one or more previous blocks do not belong to neighbouring blocks of the current block or the MVs for control points of one of the neighbouring blocks of the current block are used to derive said one or more new affine Merge candidates;
• generate a Merge candidate list including said one or more new affine Merge candidate;
• and
• if the current block is coded using the Merge mode, encode the current block at the video encoder side or decode the current block at the video decoder side using the Merge candidate list, wherein the current block is coded using motion information of a Merge candidate in the Merge candidate list as indicated by a Merge index.