H.266

H.266, formally known as Versatile Video Coding (VVC), is a video compression standard developed jointly by the ITU-T and ISO/IEC through their collaborative teams, the Video Coding Experts Group (VCEG) and the Moving Picture Experts Group (MPEG). It was finalized as ITU-T Recommendation H.266 and ISO/IEC 23090-3 in July 2020, succeeding the widely used H.265/HEVC standard. The primary goal of the codec is to provide a significant improvement in compression efficiency, targeting a 50% bitrate reduction for equivalent perceptual quality compared to its predecessor, thereby addressing the growing demands of ultra-high-definition video, 360-degree video, and immersive media.

Overview

The development of H.266 was driven by the exponential growth in global video traffic, fueled by services like Netflix, YouTube, and video conferencing platforms, alongside emerging applications such as virtual reality and 8K resolution broadcasting. The standard is designed to be highly versatile, efficiently compressing video content ranging from standard definition to resolutions beyond 8K UHD and for a wide range of bitrates. Key organizations involved in its creation include the Fraunhofer Society, which played a leading role, along with major industry players like Qualcomm, Samsung, and Huawei. The completion of the standard was a major milestone for the Joint Video Experts Team (JVET), the collaborative body formed from MPEG and VCEG.

Technical specifications

H.266 introduces several advanced coding tools over H.265/HEVC to achieve its superior compression. It supports a more flexible partitioning structure using a multi-type tree, allowing for coding tree units (CTUs) up to 128x128 pixels. Enhanced prediction techniques include more sophisticated intra prediction modes and affine motion compensation for inter prediction. The standard also incorporates improved transform coding, such as multiple transform selection and non-separable secondary transforms. For entropy coding, it uses context-adaptive binary arithmetic coding (CABAC) with enhanced context modeling. Furthermore, H.266 includes specific tools for screen content coding, adaptive loop filtering, and decoding capability information for hardware acceleration.

Development and standardization

The project to develop a successor to H.265/HEVC began in earnest around 2015, with the Joint Video Exploration Team (JVET) forming in 2016 to assess new coding technologies. Formal standardization work under the JVET commenced in 2017, with the first draft of the VVC standard released in 2019. The final standard was ratified in July 2020 following a rigorous testing process involving subjective quality assessments using methodologies like the Mean Opinion Score. The development process saw significant contributions from companies across the globe, including Apple Inc., Broadcom Inc., Ericsson, and Intel, reflecting its importance for future broadcasting, streaming media, and 5G networks.

Comparison with other video codecs

Compared to H.265/HEVC, H.266 provides approximately 50% better compression efficiency, meaning a video encoded with H.266 can be half the file size while maintaining similar visual quality. When compared to the older H.264/AVC, the bitrate savings are even more substantial, often cited as up to 75%. Against contemporary royalty-free codecs like AV1, developed by the Alliance for Open Media, H.266 generally offers superior compression performance, particularly at higher resolutions, though AV1 has seen broader initial adoption in web environments like Google Chrome and Mozilla Firefox. The complexity of H.266's encoding and decoding processes is significantly higher than both H.265/HEVC and VP9, posing challenges for real-time implementation on existing mobile devices and requiring more advanced silicon.

Applications and adoption

H.266 is poised to be critical for next-generation video services and infrastructure. Its efficiency makes it ideal for delivering 4K and 8K UHD content in broadcasting via standards like ATSC 3.0 and DVB, and for streaming on platforms such as Disney+ and Amazon Prime Video. It is also highly relevant for immersive video formats used in augmented reality applications and for professional media production and archiving. Early adoption is being driven by companies like Tencent, which has conducted trials, and chipset designers like MediaTek. However, widespread deployment faces hurdles related to patent licensing through pools like the Access Advance VVC pool and the need for new hardware acceleration support in devices from manufacturers like Sony and LG Electronics.

Category:Video codecs Category:ITU-T recommendations Category:ISO/IEC standards