Patent ID: 8254443

Claim:
An improved latency rate distortion optimisation apparatus comprising: a forward quantiser unit for processing input coefficients (W ij ); an inverse quantiser unit coupled to the forward quantiser unit; and at least one look-up-table of quantiser values for use by the forward and inverse quantiser units; wherein the at least one look-up-table of quantiser values further includes any one or more of the following modified quantiser multiplication factors: negative forward quantiser multiplication factors (−MF); pre-shifted forward quantiser multiplication factors (MF ps ); negative pre-shifted forward quantiser multiplication factors (−MF ps ); negative inverse quantiser multiplication factors (−V); pre-shifted inverse quantiser multiplication factors (V ps ), wherein the pre-shifted quantiser multiplication factors are pre-shifted dependent upon a value derived from a Quantization parameter (QP) value of a macroblock under test; or negative pre-shifted inverse quantiser multiplication factors (−V ps ); and the forward quantiser unit is arranged to operate on the input coefficients (W ij ) using one of the modified forward quantiser multiplication factors; and the inverse quantiser unit is arranged to operate on the output of the forward quantiser unit using one of the modified inverse quantiser multiplication factors.