Patent ID: 7738554

Claim:
A computer-implemented method of decoding video using a video decoder, the method comprising: receiving encoded data in a bit stream and decoding a video picture using the encoded data, including: receiving a first code that indicates a value for a DC differential for a DC coefficient of a block of the video picture; decoding the first code to determine the value for the DC differential; receiving a second code that indicates a refinement of the value for the DC differential; decoding the second code to determine the refinement of the value for the DC differential; and reconstructing the DC differential using the value for the DC differential and the refinement, including adding the refinement to a multiple of the value for the DC differential, wherein the DC differential represents a difference of the DC coefficient from a DC predictor, wherein the multiple of the value for the DC differential is determined by multiplying the value for the DC differential by a factor that depends on quantization step size, and wherein: if the quantization step size is 1, the factor is 4; and if the quantization step size is 2, the factor is 2.