A Compact 32-Pixel TU-Oriented and SRAM-Free Intra Prediction VLSI Architecture for HEVC Decoder

In the High Efficiency Video Coding (HEVC), a variety of CU sizes and intra prediction modes significantly improve coding efficiency, but also bring higher computational complexity. This paper proposes a new compact VLSI architecture for HEVC intra prediction, which is geared towards 8K video decoding. It supports all the transform unit (TU) sizes and 35 HEVC intra prediction modes. First, this paper introduces a TU-oriented intra predictor with a throughput of 32 pixels, which can be newly arranged with the TU size. It can be a line of 32 pixels, two lines of 16 pixels, 4 lines of 8 pixels or four lines of four pixels. This TU-oriented architecture allows intra-prediction and inverse discrete cosine transform (IDCT) to be computed in parallel, removing the memory between them. In addition, a horizontal and vertical line buffer for reference sample is proposed, which only cost 0.8K bit and is implemented by register files with SRAM-free. Finally, to further reduce hardware consumption, multipliers can be shared in the prediction. The implementation result shows that the compact architecture supports 8K video application and costs 66.2K logic gates, which is synthesized with the TSMC 65nm process under 400MHz.