A unified transform unit for H.264

This paper presents a unified transform unit that can perform forward integer transform, quantization, dequantization, integer transform, and hadamard in H.264/AVC. To reduce hardware cost, the proposed uses shifters, adder/subtractors instead of for quantization and de-quantization, and reuses 1-D unit for all supporting transforms. Hardware is maximized to achieve required performance with cost. It takes about 250 cycles to perform forward integer , quantization, de-quantization, and inverse integer for a macroblock, and additional 35 cycles for forward inverse hadamard transforms. The architecture can process 6,000 frames of QCIF at 150 MHz. The unified transform can be widely used in mobile devices.