• Electronics and Telecommunications Trends
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• v.37 no.3
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• pp.52-63
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• 2022

Immersive media, also known as spatial media, has become essential with the decrease in face-to-face activities in the COVID-19 pandemic era. Teleconference, metaverse, and digital twin have been developed with high expectations as immersive media services, and the demand for hyper-realistic media is increasing. Under these circumstances, MPEG-I Immersive Media is being standardized as a technologies of navigable virtual reality, which is expected to be launched in the first half of 2024, and the Audio Group is working to standardize the immersive audio technology. Following this trend, this article introduces the trend in MPEG-I immersive audio standardization. Further, it describes the features of the immersive audio rendering technology, focusing on the structure and function of the RM0 base technology, which was chosen after evaluating all the technologies proposed in the January 2022 "MPEG Audio Meeting."

• Journal of Broadcast Engineering
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• v.27 no.6
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• pp.861-871
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• 2022

The moving picture experts group (MPEG) developed the MPEG immersive video (MIV) standard for efficient compression of multiple immersive videos representing natural contents and computer graphics. The MIV compresses multiple immersive videos and generates multiple output videos which are defined as atlases. However, there is a synchronization issue of multiple decoders in a legacy device when decoding multiple encoded atlases. This paper proposes and implements the geometry packing method for adaptive control of decoder instances for low-end and high-end devices. The proposed method on the recent version of the MIV reference software worked correctly.

• Journal of Broadcast Engineering
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• v.25 no.5
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• pp.723-733
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• 2020

In this paper, MPEG-I Immersive Audio Standardization and related trends are presented. MPEG-I Immersive Audio, which is under the development of standard documents at the exploration stage, can make a user interact with a virtual scene in 6 DoF manner and perceive sounds realistic and matching the user's spatial audio experience in the real world, in VR/AR environments that are expected as killer applications in hyper-connected environments such as 5G/6G. In order to do this, MPEG Audio Working Group has discussed the system architecture and related requirements for the spatial audio experience in VR/AR, audio evaluation platform (AEP) and encoder input format (EIF) for assessing the performance of submitted proponent technologies, and evaluation procedures.

• Journal of Broadcast Engineering
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• v.27 no.5
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• pp.773-793
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• 2022

The moving picture experts group (MPEG) immersive video (MIV) coding standard has been established to support six degrees of freedom (6DoF) in virtual reality (VR) by transmitting high-quality multiple immersive videos. The MIV exploits two approaches considering tradeoff between bandwidth and computational complexity: 1) eliminating correlation between multi-view videos or 2) selecting representative videos. This paper presents performance analysis on intermediate synthesized views on source view positions and synthesized pose traces using high-efficiency video coding (HEVC) and versatile video coding (VVC) for above-mentioned two approaches.

• Journal of Broadcast Engineering
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• v.27 no.2
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• pp.216-227
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• 2022

The MPEG-I (Immersive) group is working on a standardization project for immersive video that provides 6 degrees of freedom (6DoF). The MPEG Immersion Video (MIV) standard technology is intended to provide limited 6DoF based on depth map-based image rendering (DIBR) technique. Many efficient coding methods have been suggested for MIV, but efficient transmission strategies have received little attention in MPEG-I. This paper proposes group-based adaptive rendering method for immersive video streaming. Each group can be transmitted independently using group-based encoding, enabling adaptive transmission depending on the user's viewport. In the rendering process, the proposed method derives weights of group for view synthesis and allocate high quality bitstream according to a given viewport. The proposed method is implemented through the Test Model for Immersive Video (TMIV) test model. The proposed method demonstrates 17.0% Bjontegaard-delta rate (BD-rate) savings on the peak signalto-noise ratio (PSNR) and 14.6% on the Immersive Video PSNR(IV-PSNR) in terms of various end-to-end evaluation metrics in the experiment.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.911-921
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• 2020

Recently, MPEG-I (Immersive) has been exploring compression performance through standardization projects for immersive video. The MPEG Immersion Video (MIV) standard technology is intended to provide limited 6DoF based on depth map-based image rendering (DIBR). MIV is a model that processes the Basic View and the residual information into an Additional View, which is a collection of patches. Atlases have the unique characteristics depending on the kind of the view they are included, requiring consideration of the compression efficiency. In this paper, the performance comparison analysis of screen content coding tools such as intra block copy (IBC) is conducted, based on the pattern of various views and patches repetition. It is demonstrated that the proposed method improves coding performance around -15.74% BD-rate reduction in the MIV.

• Journal of Broadcast Engineering
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• v.24 no.2
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• pp.273-280
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• 2019

360 video is attracting attention as immersive media with the spread of VR applications, and MPEG-I (Immersive) Visual group is actively working on standardization to support immersive media experiences with up to six degree of freedom (6DoF). In virtual space of omnidirectional 6DoF, which is defined as a case of degree of freedom providing 6DoF in a restricted area, looking at the scene at any viewpoint of any position in the space requires rendering the view by synthesizing additional viewpoints called virtual omnidirectional viewpoints. This paper presents the performance results on view synthesis and their analysis, which have been done as exploration experiments (EEs) of omnidirectional 6DoF in MPEG-I. In other words, experiment results on view synthesis in various aspects of synthesis conditions such as the distances between input views and virtual view to be synthesized and the number of input views to be selected from the given set of 360 videos providing omnidirectional 6DoF are presented.

• Journal of Broadcast Engineering
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• v.28 no.2
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• pp.194-212
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• 2023

The MPEG immersive video (MIV) coding standard achieved high compression efficiency by removing inter-view redundancy and merging the residuals of immersive video which consists of multiple texture (color) and geometry (depth) pairs. Grouping of views that represent similar spaces enables quality improvement and implementation of selective streaming, but this has not been actively discussed recently. This paper introduces an implementation of group-based encoding into the recent version of MIV reference software, provides experimental results on optimal views and videos per group, and proposes a decision method for optimal number of videos for global immersive video representation by using portion of residual videos.

• Journal of Broadcast Engineering
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• v.27 no.7
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• pp.974-984
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• 2022

In this paper, we introduce the minimum and maximum distance setting methods used in geometric distance attenuation processing, which is one of spatial sound reproduction methods. In general, sound attenuation by distance is inversely proportional to distance, that is 1/r law, but when the relative distance between the user and the audio object is very short or long, exceptional processing might be performed by setting the minimum distance or the maximum distance. While MPEG-I Immersive Audio's RM0 uses fixed values for the minimum and maximum distances, this study proposes effective methods for setting the distances considering the signal gain of an audio object. Proposed methods were verified through simulation of the proposed methods and experiments using RM0 renderer.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.11a
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• pp.54-57
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• 2022

다수의 색상 및 거리 정보로 구성된 몰입형 영상 부호화를 위한 MPEG immersive video (MIV) 표준은 각 시점의 영상 간 중복성 제거 및 잔여 영상 병합을 통한 압축률 향상을 목표로 한다. 시점에 따른 카메라 그룹핑을 통해 압축률 향상이 가능하나, 그룹 기반 MIV 부호화 기술은 최근 활발히 논의되고 있지 않다. 따라서 본 논문은 최신 버전의 MIV 참조 소프트웨어에 그룹 기반 부호화 기술을 이식하고 적응적 스트리밍을 위한 그룹 기반 부호화 기술의 효율을 검증하였다.