Beyond HEVC: Progress update on Versatile Video Coding
Today marks World Standards Day 2019, an annual tribute to the collaborative efforts of the thousands of experts worldwide that dedicate their time and expertise to the development of international standards.
2019’s celebrations are themed ‘video standards create a global stage’ in recognition of the pioneering standardization work behind the advanced video technologies of our time.
World Standards Day message from the heads of IEC, ISO and ITU
Video accounts 80 per cent of all consumer Internet traffic. The majority of this traffic is coded using international standards developed in collaboration by the world’s three leading standards bodies, IEC, ISO and ITU.
This video coding collaboration has been honoured with two Primetime Emmy Awards, the first in 2008 for ITU H.264 | MPEG-4 Advanced Video Coding (AVC) and the second in 2017 for High Efficiency Video Coding (HEVC, published as ITU H.265 | ISO/IEC 23008-2).
But what’s next for this industry-defining standardization work?
Versatile Video Coding
The Versatile Video Coding (VVC) project is on course for completion by mid-2020.
The project is led by the Joint Video Experts Team, a collaborative team formed by the ITU-T Study Group 16 Video Coding Experts Group and ISO/IEC JTC1 SC29/WG11 (Moving Picture Experts Group, MPEG).
The primary objective of VVC is to provide a significant improvement in compression performance over HEVC.
“Our consumption of video is increasing,” says Benjamin Bross, a video coding and analytics expert at the Fraunhofer Heinrich Hertz Institute.
“Encoding and compressing video efficiently continues to grow in importance.”
Successive IEC-ISO-ITU video coding standards have each delivered bit-rate savings of 50 per cent over their predecessors.
The VVC projects is demonstrating savings of 37.7 per cent over HEVC – “comparable to HEVC’s improvement over AVC at the same stage of development,” says Bross.
But, as its name suggests, the VVC project values both versatility and coding efficiency in equal measure.
Bross highlights three forms of VVC versatility:
1. Screen content coding
Video coding standards are typically optimized for natural video, “but screen content has completely different signal characteristics,” says Bross.
The very first version of VVC will include specialized tools for the coding of screen content, the computer-generated content of applications such as screen sharing, remote desktop, and gaming.
2. Reference picture resampling
Adaptive streaming solutions enable service providers to adapt the bit rate or resolutions of their video streams to users’ available bandwidth.
“It is common to switch screen resolutions,” says Bross. “But the problem here is that you use previous pictures to predict your current picture in our whole coding design.”
VVC will enable ‘reference picture resampling’ to address exactly this challenge.
This feature also has the potential to enable spatial scalability, highlights Bross: “You could have a base layer with a lower resolution and an extension layer with a higher resolution. The best way to do that is still under investigation.”
3. Independent sub-pictures
Independent sub-pictures aim to support applications such as tiled streaming of 360-degree video.
“We could render a complete 360 video … but you always look at a certain part, and you would want that in higher resolution,” says Bross, speaking of the so-called ‘preferred viewing direction’.
VVC will enable a decoder to extract and decode a sub-picture – the preferred viewing direction – rather than decode the whole video stream.
Download Benjamin Bross’ presentation: ‘VVC on the final stretch’
- Bross’ progress update on the VVC project was presented at an ITU workshop on the future of media.
- All presentations are freely available from the workshop programme.
- Bross’ talk runs from 16:00 to 42:00 in the archive of the workshop webcast.
