OPSE: Online Per-Scene Encoding for Adaptive Http Live Streaming

In live streaming applications, typically a fixed set of bitrateresolution pairs (known as a bitrate ladder) is used during the entire streaming session in order to avoid the additional latency to find scene transitions and optimized bitrateresolution pairs for every video content. However, an optimized bitrate ladder per scene may result in (i) decreased storage or delivery costs or/and (ii) increased Quality of Experience (QoE). This paper introduces an Online Per-Scene Encoding (OPSE) scheme for adaptive HTTP live streaming applications. In this scheme, scene transitions and optimized bitrate-resolution pairs for every scene are predicted using Discrete Cosine Transform (DCT)-energy-based low-complexity spatial and temporal features. Experimental results show that, on average, OPSEyields bitrate savings of up to 48.88% in certain scenes to maintain the same VMAF, compared to the reference HTTP Live Streaming (HLS) bitrate ladder without any noticeable additional latency in streaming.