DWS-BEAM: Decoder-Wise Subpicture Bitstream Extracting and Merging for MPEG Immersive Video

With the new immersive video coding standard MPEG immersive video (MIV) and versatile video coding (VVC), six degrees of freedom (6DoF) virtual reality (VR) streaming technology is emerging for both computer-generated and natural content videos. This paper addresses the decoder-wise subpicture bitstream extracting and merging (DWS-BEAM) method for MIV and proposes two main ideas: (i) a selective streaming-aware subpicture allocation method using a motion-constrained tile set (MCTS), (ii) a decoder-wise subpicture extracting and merging method for single-pass decoding. In the experiments using the VVC test model (VTM), the proposed method shows 1.23% BD-rate saving for immersive video PSNR (IV-PSNR) and 15.78% decoding runtime saving compared to the VTM anchor. Moreover, while the MIV test model requires four decoders, the proposed method only requires one decoder.