High performance VLSI Architecture of H.265/HEVC intra prediction for 8K UHDTV video decoder

8K Ultra High Definition Television (UHDTV) requires extremely high throughput for video decoding based on H.265. In H.265, intra coding could significantly enhance video compression efficiency, at the expense of an increased computational complexity compared with H.264. For intra prediction of 8K UHDTV real-time H.265 decoding, the joint complexity and throughput issue is more difficult to solve. Therefore, based on the divide-and-conquer strategy, we propose a new VLSI architecture in this paper, including two techniques, in order to achieve 8K UHDTV H.265 intra prediction decoding. The first technique is the LUT based Reference Sample Fetching Scheme (LUT-RSFS), reducing the number of reference samples in the worst case from 99 to 13. It further reduces the circuit area and enhances the performance. The second one is the Hybrid Block Reordering and Data Forwarding (HBRDF), minimizing the idle time and eliminating the dependency between TUs by creating 3 Data Forwarding paths. It achieves the hardware utilization of 94%. Our design is synthesized using Synopsys Design Compiler in 40 nm process technology. It achieves an operation frequency of 260 MHz, with a gate count of 217.8K for 8-bit design, and 251.1K for 10-bit design. The proposed VLSI architecture can support 4320p@120 fps H.265 intra decoding (8-bit or 10-bit), with all 35 intra prediction modes and prediction unit sizes ranging from 4 × 4 to 64 × 64.