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The emerging immersive video coding standard moving picture experts group (MPEG) immersive video (MIV), which is ongoing standardization by MPEG-Immersive (MPEG-I) group, enables six degrees of freedom in a virtual reality environment that represents both natural and computer-generated scenes using multi-view video compression. The MIV eliminates the redundancy between multi-view videos and merges the residuals into multiple pictures, called an atlas. Thus, bitstreams with encoded atlases are generated and corresponding number of decoders are needed, which is challenging for the lightweight device with a single decoder. This article proposes a decoder-adaptive tiling and rate allocation method for MIV to overcome the challenge. First, the proposed method divides atlases into subpictures considering two aspects: (i) subpicture bitstream extracting and merging into one bitstream to use a single decoder and (ii) separation of each source view from the atlases for rate allocation. Second, the atlases are encoded by versatile video coding (VVC), using an extractable subpicture to divide the atlases into subpictures. Third, each subpicture bitstream is extracted, and asymmetric quality allocation for each subpictures is conducted by considering the residuals in the subpicture. Fourth, mixed-quality subpictures were merged by using the proposed bitstream merger. Fifth, the merged bitstream is decoded by using a single decoder. Finally, the viewing area of the user is synthesized by using the reconstructed atlases. Experimental results with the VVC test model (VTM) show that the proposed method achieves a 21.37% Bjøntegaard delta rate saving for immersive video peak signal-to-noise ratio and a 26.76% decoding runtime saving compared to the VTM anchor configuration. Moreover, it supports bitstreams for multiple decoders and single decoder without re-encoding, transcoding, or a substantial increase of the server-side storage. [ABSTRACT FROM AUTHOR]

Numerous wearable technology companies have recently developed several head‐mounted display (HMD) products for virtual reality (VR) services. 5G wireless networks aim at providing high‐quality 3D multimedia services such as VR, augmented reality, and mixed reality. In this study, we examine the application of millimeter‐wave (mmWave) technology to realize low‐latency wireless communication between an HMD and its content server. However, the propagation characteristics of mmWave present several challenges such as the deafness, blockage, and beam alignment problems, and interference among content servers. In this study, we focus on an environment that provides VR services in the mmWave band and introduce existing techniques for addressing such challenges. In addition, we employ a commercialized IEEE 802.11ad VR dongle to measure the actual data rate of an mmWave VR application and identify the degree to which the performance deteriorates when the above problems occur. Finally, we verify the feasibility of the proposed solutions through a simulation of several VR scenarios in the mmWave band. [ABSTRACT FROM AUTHOR]

Abstract Today, the demand for and interest in virtual reality (VR) is increasing, since we can now easily experience VR in many applications. However, the computational ability of mobile VR is limited compared to that of tethered VR. Since VR represents a 360-degree area, providing high quality only for the area viewed by the user saves considerable bandwidth. Therefore, we propose a new tile-based streaming method that transforms 360-degree videos into mobile VR using high efficiency video coding (HEVC) and the scalability extension of HEVC (SHVC). While the SHVC base layer (BL) represents the entire picture, the enhancement layer (EL) can transmit only the desired tiles by applying the proposed method. By transmitting the BL and EL using region of interest (ROI) tiles, the proposed method helps reduce not only the computational complexity on the decoder side but also the network bandwidth. [ABSTRACT FROM AUTHOR]

360-degree video streaming for high-quality virtual reality (VR) is challenging for current wireless systems because of the huge bandwidth it requires. However, millimeter wave (mmWave) communications in the 60 GHz band has gained considerable interest from the industry and academia because it promises gigabit wireless connectivity in the huge unlicensed bandwidth (i.e., up to 7 GHz). This massive unlicensed bandwidth offers great potential for addressing the demand for 360-degree video streaming. This paper investigates the problem of 360-degree video streaming for mobile VR using the SHVC, the scalable of High-Efficiency Video Coding (HEVC) standard and PC offloading over 60 GHz networks. We present a conceptual architecture based on advanced tiled-SHVC and mmWave communications. This architecture comprises two main parts. (1) Tile-based SHVC for 360-degree video streaming and optimizing parallel decoding. (2) Personal Computer (PC) offloading mechanism for transmitting uncompressed video (viewport only). The experimental results show that our tiled extractor method reduces the bandwidth required for 360-degree video streaming by more than 47% and the tile partitioning mechanism was improved by up to 25% in terms of the decoding time. The PC offloading mechanism was also successful in offloading 360-degree decoded (or viewport only) video to mobile devices using mmWave communication and the proposed transmission schemes. [ABSTRACT FROM AUTHOR]