iAVS2: A Fast Intra-Encoding Platform for IEEE 1857.4
The second generation of the audio video coding standard (AVS2), which has been issued as IEEE 1857.4, doubles the coding efficiency of AVS1 and H.264/AVC. However, the advanced techniques in AVS2 also dramatically increase the computational complexity. The research on a commercial encoder for AVS2 is still at an early stage. In this paper, we propose the first fast intra-encoding platform for AVS2, which we term iAVS2. The platform uses numerous speedup methods, including code optimization, single-instruction multiple-data acceleration, and fast algorithms for almost all the time-consuming modules. To meet different application scenarios, five different speed levels are designed in iAVS2 to provide flexible tradeoffs between compression efficiency and encoding speed. The experimental results show that the fastest speed level of iAVS2 can accelerate the AVS2 reference software (RD12.0) by <inline-formula> <tex-math notation="LaTeX">$144\times $ </tex-math></inline-formula> on average. Compared with the well-known HEVC encoder platform <inline-formula> <tex-math notation="LaTeX">$\times 265$ </tex-math></inline-formula>, iAVS2 can provide over 10% bit rate saving at a similar coding speed. For the UHD and 1080 sequences, iAVS2 outperforms <inline-formula> <tex-math notation="LaTeX">$\times 265$ </tex-math></inline-formula> at all speed levels.