Fast Block Structure Determination in AV1-based Multiple Resolutions Video Encoding
This work addresses the efficiency problem for video streaming services by providing an incremental improvement that halves performance loss compared to state-of-the-art methods without sacrificing time savings.
The paper tackles the bottleneck of high-resolution encoding in adaptive HTTP streaming by proposing a fast block structure determination algorithm for AV1-based multiple resolutions video encoding, which reduces encoding time by 30.1%-36.8% while maintaining low BD-rate at 0.71%-1.04%.
The widely used adaptive HTTP streaming requires an efficient algorithm to encode the same video to different resolutions. In this paper, we propose a fast block structure determination algorithm based on the AV1 codec that accelerates high resolution encoding, which is the bottle-neck of multiple resolutions encoding. The block structure similarity across resolutions is modeled by the fineness of frame detail and scale of object motions, this enables us to accelerate high resolution encoding based on low resolution encoding results. The average depth of a block's co-located neighborhood is used to decide early termination in the RDO process. Encoding results show that our proposed algorithm reduces encoding time by 30.1%-36.8%, while keeping BD-rate low at 0.71%-1.04%. Comparing to the state-of-the-art, our method halves performance loss without sacrificing time savings.