Patent ID: 8665965

Claim:
A decoder comprising: a processor; a computer-readable storage medium storing instructions, which, when processed by the processor, cause the processor to perform operations, the operations comprising: determining a quantization parameter from a bitstream; generating a luminance scalar according to a first piece-wise linear transformation of the quantization parameter, wherein: (i) the luminance scalar equals 8 whenever the quantization parameter falls within the values 1 through 4, inclusive; (ii) the luminance scalar equals 2 times the quantization parameter whenever the quantization parameter falls within the values 5 through 8, inclusive; (iii) the luminance scalar equals the quantization parameter plus 8 whenever the quantization parameter falls within the values 9 through 24, inclusive; and (iv) the luminance scalar equals 2 times the quantization parameter minus 16; inverse quantizing a DC coefficient of a respective luminance block of up to four luminance blocks by the luminance scalar to yield a respective inverse quantized DC coefficient; transforming data of the up to four luminance blocks, including the respective inverse quantized DC coefficient, according to an inverse discrete cosine transform; and merging the transformed data of the up to four luminance blocks to generate image data associated with a respective macroblock.