An UVLC encoder architecture for H.26L

Variable length code (VLC) is widely used in various compression applications. The latest under development video coding standard, H.26L, uses a unique pattern VLC code called UVLC in the test model document. In this paper, an UVLC encoder architecture is proposed to meet the requirements of TML8. This architecture is composed of a code splitter, a first 1 detector, a shifter, a length accumulator, and a code mux/output. A modified code number technique and auto self alignment technique are used to simplify the architecture. By using these techniques, the size of this architecture is much smaller when compared to traditional VLC encoders. It has been synthesized in a 0.35 μm cell library. The size of this architecture is 980 gates while critical path is less than 6 ns.