General Video Coding Technology in Responses to the Joint Call for Proposals on Video Compression With Capability Beyond HEVC

Abstract

After the development of the High-Efficiency Video Coding Standard (HEVC), ITU-T VCEG and ISO/IEC MPEG formed the Joint Video Exploration Team (JVET), which started exploring video coding technology with higher coding efficiency, including development of a Joint Exploration Model (JEM) algorithm and a corresponding software implementation. The technology explored in the last version of the JEM further increases the compression capabilities of the hybrid video coding approach by adding new tools, reaching up to 30% bit rate reduction compared to HEVC based on the Bjøntegaard delta bit rate (BD-rate) metric, and further improvement beyond that in terms of subjective visual quality. This provided enough evidence to issue a joint Call for Proposals (CfP) for a new standardization activity now known as Versatile Video Coding (VVC). All technology proposed in the responses to the CfP was based on the classic block-based hybrid video coding design, extending it by new elements of partitioning, intra-and inter-picture prediction, prediction signal filtering, transforms, quantization/scaling, entropy coding, and in-loop filtering. This article provides an overview of technology that was proposed in the responses to the CfP, with a focus on techniques that were not already explored in the JEM context.

Scalable Panoramic Wireless Video Streaming Relying on Optimal-Rate FEC-Coded Adaptive QAM

“…Panoramic video, which offers a 360 degree immersive experience for the users, has gradually become a popular video format for presenting flawless ultra-high resolution contents. To reduce the demanding bitrate requirement of panoramic video streams, the Joint Video Expert Team (JVET) has been dedicated for years to the conception of the next-generation video coding standard, namely the H.266/Versatile Video Coding (VVC) standard [1], whose objective is to provide a significant improvement in compression performance over the existing H.265/High Efficiency Video Coding (HEVC) standard [2].…”

“…The demultiplexer of Fig. 4 splits the video streams into three sub-streams, namely 1) the BL of the predicted FoV {f 1 i,j } i∈F oV , 2) the BL outside the FoV tiles {f 1 i,j } i / ∈F oV , and 3) the EL of the predicted FoV {f 2 i,j } i∈F oV , corresponding to the Class 1, 2 and 3, respectively, where…”

“…indicates the bits of i-th tile of the l-th video sublayer of the j-th video frame. The three sub-streams are then encoded by the FEC Encoders 1, 2, 3 according to the code-rate sets of {r 1 i,j } i∈F oV , {r 1 i,j } i / ∈F oV and {r 2 i,j } i∈F oV , respectively, as depicted in Fig. 4, which are optimized by the Coding Rate Allocation block of Fig.…”

“…Let us now consider the throughput of the three modulation modes. Specifically, BPSK conveys the C1 BL bit streams of the FoV tiles {f 1 i,j } i∈F oV only, while 16QAM transmits the C1 and C2 BL of all tiles,…”

“…Hence, in BPSK the coding rate allocation block of Fig. 4 explores the most appropriate coding rate allocation for {f 1 i,j } i∈F oV only, while in the 16QAM and 128QAM scenarios, a more complex coderate optimization algorithm may be invoked for the sake of exploiting the globally optimal FEC coding rates for achieving the highest uncoded source-rate, whilst progressively offering a stronger protection to the more important information. Additionally, we emphasize that the AQAM design can be substituted by the family of sophisticated multi-functional Multiple-Input Multiple-Output (MIMO) techniques, such as Spatial Modulation (SM) [48], STSK [49] and MS-STSK [26].…”