FPGA Implementation of Integer Transform and Quantizer for H.264 Encoder

Abstract

This paper deals with the process of Transformation and Quantization that is carried out on each inter-predicted residual block in a video encoding process and their reduced complexity hardware implementation. H.264/AVC utilizes 4?×?4 integer transform, which is derived from the 4?×?4 DCT. We propose, a reduced complexity algorithm and a pipelined structure for the Core forward integer transform module. A multiplier-less architecture is realized with less number of shifts and adds compared to existing works. The corresponding inverse transform is exactly reversible. Each of the transformed coefficients is quantized by a scalar quantizer. The quantization step size can be varied from macroblock to macroblock. The proposed unified pipelined architecture outperforms many recent implementations in terms of gate count and is capable of processing a 4?×?4 residual block in 4 clock cycles.