System and method for combined inter and intra prediction

A video encoding device, comprising one or more processors and one or more storages coupled to the one or more processors, wherein the video encoding device is configured to perform operations comprises:

• generating an inter prediction of a current coding block based on an inter prediction mode;
• generating an intra prediction of the current coding block based on an intra prediction mode;
• generating a final prediction of the current coding block based on the inter prediction and the intra prediction;
• determining that a prediction mode of the current coding block is treated as one unified mode when constructing a most probable mode (MPM) list of a neighboring coding block, the unified mode being predefined as an inter mode, or being predefined as an intra mode;
• and
• forming a video bit-stream with information that a combined inter and intra prediction mode is applied to the current coding block.

A method of video decoding, comprising:

• receiving a video bit-stream, wherein the video bit-stream is formed with information that a combined inter and intra prediction mode is applied to the current coding block;
• generating an inter prediction of a current coding block based on an inter prediction mode;
• generating an intra prediction of the current coding block based on an intra prediction mode;
• generating a final prediction of the current coding block based on the inter prediction and the intra prediction;
• and
• determining that a prediction mode of the current coding block is treated as one unified mode when constructing a most probable mode (MPM) list of a neighboring coding block, the unified mode being predefined as an inter mode, or being predefined as an intra mode.