Explicit signaling for block based adaptive weighting factors

A device for processing video data, the device comprising a memory for storing computer instructions and a processor in communication with the memory, wherein, when the processor executes the computer instructions, the processor is configured to cause the device to:

• receive a video bitstream comprising a current block in a current frame and a reference block in a reference frame, the reference block being used for predicting the current block and being identified by a motion vector associated with the current block;
• receive, from the video bitstream, a syntax element indicating a scale factor (α);
• determine the scale factor (α) based on a value of the syntax element, wherein the scale factor (α) is used for predicting the current block;
• predict the current block using an equation as following:
• p
• ′
• (
• x
• ′
• )
• =
• α
• *
• p
• ⁡
• (
• x
• )
• +
• β
• wherein:
• p′(x′) is a predicted sample in the current block, p(x) is a collocated reference sample in the reference block corresponding to p′(x′), a correspondence between p′(x′) and p(x) is established by the motion vector, α is the determined scale factor based on the value of the syntax element, and β is an offset;
• and
• reconstruct the current block based on the predicted current block.

A non-transitory storage medium for storing computer readable instructions, the computer readable instructions, when executed by a processor, causing the processor to:

• receive a video bitstream comprising a current block in a current frame and a reference block in a reference frame, the reference block being used for predicting the current block and being identified by a motion vector associated with the current block;
• receive, from the video bitstream, a syntax element indicating a scale factor (α);
• determine the scale factor (α) based on a value of the syntax element, wherein the scale factor (α) is used for predicting the current block;
• predict the current block using an equation as following:
• p
• ′
• (
• x
• ′
• )
• =
• α
• *
• p
• ⁡
• (
• x
• )
• +
• β
• wherein:
• p′(x′) is a predicted sample in the current block, p(x) is a collocated reference sample in the reference block corresponding to p′(x′), a correspondence between p′(x′) and p(x) is established by the motion vector, α is the determined scale factor based on the value of the syntax element, and β is an offset;
• and
• reconstruct the current block based on the predicted current block.