A new differential and lossless Reference Frame Variable-Length Coder: An approach for high definition video coders

This paper presents a novel solution for external memory bandwidth reduction in video coding systems. The approach is based on reference frame compression, using a differential coding and a hardware-aware adaptation of the traditional Huffman algorithm, besides, it is a lossless solution fully compliant to state-of-art video coding standards, as H.264/AVC and HEVC. This solution is called DRFVLC (Differential Reference Frame Variable-Length Coder) and it uses differential coding to concentrate the samples values distribution. With the samples concentrated, an efficient static Huffman coding is applied to represent them in fewer bits. The DRFVLC reaches an average compression rate higher than 60% for the evaluated HD 1080p video sequences. This compression rate also indicates the external memory bandwidth reduction achieved with our technique. This solution can be easily implemented in hardware demanding one differentiator and a simple variable-length coder.