HEVC Demonstrates its High Efficiency
HEVC Version 1 demonstrates it has achieved more than 50% bitrate savings compared to MPEG 4 AVC/H.264, the MPEG standards group announced following its 108th meeting held at the beginning of April in Valencia, Spain.
In a verification test campaign of the HEVC, ITU-T Rec H.265 | ISO/IEC 23008-2 compression standard following the finalisation of the standard last year “a formal subjective quality assessment has been executed using a large variety of video material, ranging from wide-screen VGA resolution up to 4K. The material had not previously been used in optimizing HEVC's compression technology”, MPEG, announced in a prepared statement, adding: “Clear evidence was found that HEVC is able to achieve 50% bitrate savings and more, compared to the AVC High Profile”. The results will be made publicly available in the report N14420, to be published on the MPEG website.
HEVC's scope continues to be extended with a call for proposals on Screen Content Coding, the compression of video containing rendered graphics and animation. This extention is scheduled for completion by the end of 2015.
HEVC's 2nd edition includes support for additional colour formats and higher precision. The ‘Range Extensions amendment’, with technology allowing efficient compression of video content for colour sampling formats beyond 4:2:0 and up to 16 bits of processing precision has been finalised. In particular, the lossless and near lossless range of visual quality is more efficiently compressed than is possible with the current version 1 technology.
Web Video Coding the standard for a worldwide, reasonable and non-discriminatory, and free of charge licensable online compression scheme for use in browser has reached the final stage before approval. MPEG expects to complete the Final Draft International Standard in February 2015.
MPEG is also working on standardising what it refers to as ‘free-viewpoint television’. A public seminar on FTV (Free-viewpoint Television) will be held on July 8th to align MPEG's future standardization of FTV technologies with users and industry needs. Targeted application scenarios are Super Multiview Displays “where hundreds of very densely rendered views provide horizontal motion parallax for realistic 3D visualization, extracted from a dense or sparse set of input views/cameras in a circular or linear arrangement”.
“Integral Photography, where 3D video with both horizontal and vertical motion parallax are captured for realistic display”. And “Free Navigation that allows the user to freely navigate or fly through the scene, not just along predefined pathways”.
MPEG expects that future FTV systems will require new functionalities such as a substantial increase in coding efficiency and rendering capability compared to technology currently available. The FTV initiative will also consider novel means for acquiring 3D content that have recently emerged, e.g. plenoptic and light field cameras. You are invited to join the FTV seminar to learn more about MPEG activities in this area and to help revolutionise the viewing experience.
The increases in spatial resolution and colour resolution, scalable coding and autostereoscopic 3D, or in MPEG speak Multi-view, leads to amendments in the trusty old MPEG-TS, transport stream layer. The amendment specifies transport of layered coding extensions for the scalable and multiview enhancements of HEVC, and the signaling of associated descriptors so that different layers can be encapsulated and transported individually.
To support the new standards to offer 4K/8K UHDTV services by using a newly developed MPEG standard, MPEG Media Transport (MMT) an effort to promote the new transport layer standard has begun in Japan with a growing number of companies implementing MMT for various applications. MPEG is organising MMT Developers' Day in conjunction with its 109th meeting this July in Sapporo, Japan.
MPEG is also working on 3D audio and dynamic range control. The DRC system provides comprehensive control to adapt the audio as appropriate for the particular content, the listening device, environment, and user preferences. The loudness control can be applied to meet regulatory requirements and to improve the user experience, especially for content with large loudness variations.
By Donald Koeleman, Broadband TV News
