Abstract: A resolution scaler of the present invention uses a shift adder instead of a multiplier for scaling an input resolution. The resolution scaler is provided with a counter controller and a pixel scaler. The counter controller outputs a weight to the pixel scaler. The pixel scaler includes a first shift adder for outputting the first shift value by adding a plurality of first shift arguments generated by shifting the current pixel data, a second shift adder for outputting the second shift value by adding a plurality of second shift arguments generated by shifting the previous pixel data, and an adder for outputting the scaled pixel data by adding the first shift value and the second shift value.

Abstract: A backtracking apparatus and method for adaptively control a threshold time is disclosed. The present invention, for backtracking survivor paths for trellis code data, wherein the trellis decoder has a trellis diagram, including: a tracking unit for backtracking a set of survivor path during a predetermined threshold time; a storage unit for storing a previous set of survivor paths; a determination unit for determining whether or not the previous set of survivor paths are converged a node to generate a convergence signal representing whether or not converging; a control unit for controlling the threshold time and response to the convergence signal to thereby backtracking the survivor paths during a controlled threshold time. The present invention can increase a performance of a system using the viterbi decoder and decrease processing time by adaptively controlling the threshold time when backtracking a trellis code data.