Efficient Parallel Architecture for a Real-time UHD Scalable HEVC Encoder

The scalable extension (SHVC) of the High Efficiency Video Coding (HEVC) allows encoding in layers a video with multiple quality level such as resolution, bit-depth or Signal to Noise Ratio (SNR). Compared to the equivalent HEVC simulcast, the SHVC extension provides inter-layer prediction mechanisms enabling significant bit-rate savings. Moreover these inter-layer prediction mechanisms are less complex than those from former standards. Therefore, SHVC seems a promising solution for both broadcast and storage applications and is considered in the ATSC 3.0 as video coding solution. Indeed the spatial scalability is an application use-case considered in the ATSC 3.0. This paper proposes a scalable multi-layer architecture combining pipelined software HEVC encoders. The proposed architecture provides a good trade-off between parallelism over layer and latency. Moreover two configurations are proposed for Live or File encodings with real-time or best coding efficiency targets, respectively. Results present a 2x spatial scalability application of this architecture achieving in a low-delay configuration real-time video encodings of 1080p60 and 1600p30 sequences. Moreover the proposed SHVC solution also demonstrated real-time encodings of UHD contents at an ATSC 3.0 meeting in random-access configuration.