Motion prediction in video coding

An apparatus for encoding a block of pixels, the apparatus comprising:

• at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the processor, cause the apparatus to:
• determine, for a current block, a first reference block based on a first motion vector and a second reference block based on a second motion vector, wherein the pixels of the current block, the first reference block, and the second reference block have values with a first precision;
• use said first reference block to obtain a first prediction, said first prediction having a second precision, which is higher than said first precision;
• use said second reference block to obtain a second prediction, said second prediction having the second precision;
• obtain a combined prediction based at least partly upon said first prediction and said second prediction;
• decrease a precision of said combined prediction by shifting bits of the combined prediction to the right;
• and
• encode residual data in a bitstream, wherein the residual data is determined based upon a difference between the combined prediction and the block of pixels.

A computer program product for encoding a block of pixels, the computer program product comprising at least one non-transitory computer readable storage medium having computer executable program code portions stored therein, the computer executable program code portions comprising program code instructions configured to:

• determine, for a current block, a first reference block based on a first motion vector and a second reference block based on a second motion vector, wherein the pixels of the current block, the first reference block, and the second reference block have values with a first precision;
• use said first reference block to obtain a first prediction, said first prediction having a second precision, which is higher than said first precision;
• use said second reference block to obtain a second prediction, said second prediction having the second precision;
• obtain a combined prediction based at least partly upon said first prediction and said second prediction;
• decrease a precision of said combined prediction by shifting bits of the combined prediction to the right;
• and
• encode residual data in a bitstream, wherein the residual data is determined based upon a difference between the combined prediction and the block of pixels.

A method for decoding a block of pixels, the method comprising:

• determining, for a current block, a first reference block based on a first motion vector and a second reference block based on a second motion vector, wherein the pixels of the current block, the first reference block, and the second reference block have values with a first precision;
• using said first reference block to obtain a first prediction, said first prediction having a second precision, which is higher than said first precision;
• using said second reference block to obtain a second prediction, said second prediction having the second precision;
• obtaining a combined prediction based at least partly upon said first prediction and said second prediction;
• decreasing a precision of said combined prediction by shifting bits of the combined prediction to the right;
• and
• reconstructing the block of pixels based on the combined prediction.

An apparatus for decoding a block of pixels, the apparatus comprising:

• at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the processor, cause the apparatus to:
• determine, for a current block, a first reference block based on a first motion vector and a second reference block based on a second motion vector, wherein the pixels of the current block, the first reference block, and the second reference block have values with a first precision;
• use said first reference block to obtain a first prediction, said first prediction having a second precision, which is higher than said first precision;
• use said second reference block to obtain a second prediction, said second prediction having the second precision;
• obtain a combined prediction based at least partly upon said first prediction and said second prediction;
• decrease a precision of said combined prediction by shifting bits of the combined prediction to the right;
• and
• reconstruct the block of pixels based on the combined prediction.

A computer program product for decoding a block of pixels, the computer program product comprising at least one non-transitory computer readable storage medium having computer executable program code portions stored therein, the computer executable program code portions comprising program code instructions configured to:

• determine, for a current block, a first reference block based on a first motion vector and a second reference block based on a second motion vector, wherein the pixels of the current block, the first reference block, and the second reference block have values with a first precision;
• use said first reference block to obtain a first prediction, said first prediction having a second precision, which is higher than said first precision;
• use said second reference block to obtain a second prediction, said second prediction having the second precision;
• obtain a combined prediction based at least partly upon said first prediction and said second prediction;
• decrease a precision of said combined prediction by shifting bits of the combined prediction to the right;
• and
• reconstruct the block of pixels based on the combined prediction.