Versatile Video Coding (VVC) is the most recent international video coding standard jointly developed by ITU-T and ISO/IEC, which has been finalized in July 2020. VVC allows for significant bit-rate reductions around 50% for the same subjective video quality compared to its predecessor, High Efficiency Video Coding (HEVC). One year after finalization, VVC support in devices and chipsets is still under development, which is aligned with the typical development cycles of new video coding standards. This paper presents open-source software packages that allow building a complete VVC end-to-end toolchain already one year after its finalization. This includes the Fraunhofer HHI VVenC library for fast and efficient VVC encoding as well as HHI's VVdeC library for live decoding. An experimental integration of VVC in the GPAC software tools and FFmpeg media framework allows packaging VVC bitstreams, e.g. encoded with VVenC, in MP4 file format and using DASH for content creation and streaming. The integration of VVdeC allows playback on the receiver. Given these packages, step-by-step tutorials are provided for two possible application scenarios: VVC file encoding plus playback and adaptive streaming with DASH.

Transform plays a crucial role in video coding, since it is in the transform domain that the bitrate reduction happens. Recently, coding with transform competition has emerged, especially inside the ITU-T and ISO/MPEG Joint Video Exploration Team, where the adaptive multiple transforms have been thoroughly tested. In this paper, it is proposed to investigate the design of transform competition systems for the purpose of inter-predicted residuals. Several systems are proposed and evaluated in terms of coding efficiency, storage requirement, and encoding complexity. A first approach selects the best transform for a residual block in a pre-established list of transforms. An extended version is also considered, where the number of transforms varies within an image area. Experimental results show that the proposed designs achieve significant bitrate savings over high efficiency video coding from -0.2% to -1.4%.

Recently, coding of 360° video contents has been investigated in the context of over-the-top streaming services. To be delivered using terrestrial broadcast, it is required to provide backward compatibility of such content to legacy receivers. In this paper, a novel layered coding scheme is proposed to address the delivery of 360° video content over terrestrial broadcast networks. One or several views are extracted from the 360° video and coded as base layers using standard HEVC encoding. Inter-layer reference pictures are built based on projected base-layers and are used in the enhancement layer to encode the 360° video. Experimental results show that the proposed approach provides substantial coding gains of 14.99% compared to simulcast coding and enables limited coding overhead of 5.15% compared to 360° single-layer coding.

In October 2015, MPEG and ITU jointly launched the Joint Video Exploration Team (JVET) to prepare the next generation of video coding standard beyond HEVC. The tools added over HEVC, grouped into the Joint Exploration Model 3.0 (JEM-3.0), achieve over 25% of coding gains compared to HEVC for the Random-Access mode. In inter-coding mode, the transform stage consists in the Adaptive Multiple Transforms (AMT) which puts classical DCT-2 in competition with alternative transforms. In this paper, it is proposed to improve the AMT stage in inter-coding. The proposed method enables the encoder either to turn-off the AMT or to adjust its number of transforms. The introduced transforms are split into 3 nested sets: n°1 includes DST-7 and DCT-8; n°2 contains n°1 plus DST-7/DCT-8 combinations; n°3 contains n°2 plus 4 transforms learnt according to a Rate-Distortion Optimized Transform criterion (RDOT) [1]. The encoder performs a multiple-passes Coding-Tree-Unit (CTU) encoding to select the best set and signals its index into the bitstream, in a differential way. Acceleration strategies are implemented to mitigate the complexity, such as pass-cancellation and fast CTU partitioning from one pass to another.

The scalable video coding enables to compress video contents into a hierarchical layered representation, each layer depicts an enhanced version of the underlying layer. SHVC is the scalable extension of HEVC and enables spatial, SNR, color-gamut, codec and bitdepth scalability. It has been proved, in the MPEG investigations prior to the recent Call for Evidence, that SHVC can support SDR-to-HDR scalability by using the color gamut scalability, when SDR and HDR signals are placed in different color gamuts. This way, SHVC can be used to address future backward compatible issues in the HDR and WCG services deployment. In this paper, we exploit the impact of bitrate ratio over performance in scalable schemes to design an adaptive rate control algorithm suitable for such deployment, considering adjustable quality and bandwidth constraints. Our method dynamically adjusts the bitrate ratio between two layers during encoding in the most quality-related optimal way under specified constraints. The proposed method is tested on scalable combinations of HD/UHD, R.709/DCI-P3/R.2020 and SDR/HDR video contents, and reduces the average overhead introduced by SHVC compared to the single-layer HEVC encoding by 23%.

Scalable video coding consists in compressing the video sequence into a layered bitstream where each layer refers to different spatial, temporal or quality representation of the video. Scalability enables compression gain compared to the simulcast encoding of layers thanks to inter-layer predictions. The scalable HEVC extension (SHVC) is the latest scalable technology promising up to 30% bitrate gains under the common test conditions, defined by JCT-VC. These conditions do not consider UHD and use fixed quantization step, which is not relevant in operational environment. In this paper, we propose an innovative adaptive rate control algorithm for SHVC. We consider HD as a base layer and UHD as an enhancement layer, with a constant global bitrate and a dynamic bitrate ratio adjustment between layers. The proposed algorithm is evaluated on a UHD data set where enables on average a BD-BR gain of 4.25% compared to a fixed-ratio encoding.

The scalable video coding consists in encoding the video content into multiple representations, called layers, where each one refers to a specific version of the content. The scalable extension of the High Efficiency Video Coding standard SHVC is currently considered in ATSC and DVB to carry out layered and scalable programs which enables to target multiple equipments, and is also used to ensure backward compatibility with legacy receivers. In the case of hybrid delivery of HD and UHD services using SHVC, these services are encoded in two layers including base and enhancement layers, which are then broadcasted over separated channels. In this paper, a statistical multiplexing method is proposed for broadcasting of UHD services in this hybrid scenario. This innovative method considers both variable bitrate among programs and optimal SHVC layers coding, which was not considered in the existing approaches. The proposed method enables to reduce the overhead introduced by SHVC compared to the single-layer encoding by 3.3% in average while maintaining smooth quality variations among programs.

Since the introduction of the H.261 standard in 1990, the transform step has always been a key feature of video coding technologies. The successive generations of standard have always found a better way to further de-correlate the residual signals and thus improve the coding efficiency. Recently, MPEG and the ITU have jointly launched the Joint Video Exploration Team (or JVET) to prepare the next generation of video coding standard. In this context, a new approach called Adaptive Multiple Transforms (or AMT) has been introduced. Despite the provided coding efficiency, the AMT solution raises several issues especially regarding the complexity of the selected set of transforms. This can be an important issue, particularly for a future industrial adoption. In this paper, a low-complexity transform set for AMT is proposed, which aims at providing a significant reduction of the required computational power. The proposed method has been implemented in the JEM-2.0 and tested under the JVET test conditions where it provides a substantial complexity reduction of -56.5% compared to the current AMT transform set with similar R-D performance.