After the AOMedia Video 1 (AV1) bitstream specification was launched by the Alliance for Open Media, the need for converting legacy content encoded with the state-of-the-art High Efficiency Video Coding (HEVC) standard to the new format has arisen in several scenarios. However, transcoding is a complex task composed of a decoding and an encoding process in sequence, which requires long processing times and high energy consumption. This paper presents a complexity-scalable HEVC-to-AV1 transcoding scheme, which comprises 25 configuration modes chosen based on a Pareto Optimization strategy and built upon the correlation between block size decisions in HEVC and AV1. The configurations allow the AV1 encoder to inherit partitioning information from the HEVC bitstream to constrain the AV1 reencoding process, thus speeding up the transcoding operation. Experimental results showed that the proposed transcoding complexity reduction ranges from 0.41 up to 35.06%, on average, with coding efficiency losses that vary between 0.0536 and 5.3801%.

开放媒体联盟发布了AOMedia Video 1（AV1）比特流规范后，出现了将采用最新高效视频编码（HEVC）标准编码的旧内容转换为新格式的需求。几种情况。但是，转码是一项复杂的任务，由依次进行的解码和编码处理组成，需要较长的处理时间和较高的能耗。本文提出了一种可扩展性的HEVC-to-AV1转码方案，该方案包括25种基于帕累托优化策略选择的配置模式，并基于HEVC和AV1中的块大小决策之间的相关性进行构建。这些配置允许AV1编码器从HEVC比特流继承分区信息，以约束AV1重新编码过程，从而加快了转码操作。