DVB Sees A Big Role for VVC – Especially for 8K
Back at NAB in April, the writer spoke with the Media Coding Industry Forum (MC-IF). Up to then, he had been unclear about the role of the MC-IF but it was clarified there. While standardization bodies such as MPEG are responsible for creating and monitoring standards, they are not responsible for whether they become adopted or widely used. To perform the promotion function, the MC-IF was formed and so fills an important potential gap. Of particular interest to the MC-IF is the progress of the VVC codec, a topic that also concerns the 8K Association.
So, we were pleased to see an article by Virginie Drugeon, Chair of the DVB Technical Module’s Audio and Video Coding Group about developments with VVC in Europe. The DVB project is the group that standardizes broadcast technologies with the support of the EBU, CENELEC and ETSI. Although based in Europe, its standards are used in many places around the world.
Drugeon, as well as being involved with the DVB is a Senior Engineer for Digital TV Standardization at Panasonic. She started by acknowledging that there are already standards in place, but there is a need to continue to improve quality and deliver new services, especially in streaming. A bit rate as low as possible is ‘always beneficial’ to reduce the cost and environmental impact. DVB needs to be able to include the best and latest developments so VVC falls into this category.
DVB Driven by Commercial Requirements
DVB has a framework for developing standards where it first gathers the commercial requirements and then finds the best technical solutions. A commercial requirement was identified for better coding efficiency for video services, but also for more versatility especially for streamed services. VVC was chosen as the best current video codec for efficiency among those developed by MPEG. DVB tested the VVC codec (as well as others) and added it to the DVB Toolbox, meaning that DVB has specified a number of receiver conformance points for integrated receiver decoders (IRDs) for traditional TV broadcast paths but also for DVB-Player.
These conformance points have to be supported by VVC products that claim DVB compliance and video formats and profiles have been created. The specification has been published as a ‘Blue book’ – a kind of DVB publication that has been freely available since 2022 and was standardized by ETSI in 2023.
In response to a question from Lane Cooper of BizTech Reports about new services being enabled by VVC, Drugeon said that DVB has mostly been looking at new formats including what the EBU calls UltraHD 1 (3840 x 2160 ‘4K’) and UltraHD 2 (7680 x 4320 ‘8K’). These had been supported previously using HEVC, but new possibilities are enabled by VVC. For example (as demonstrated by Spin Digital and Intel), content aware encoding is possible with VVC.
Often a Lag in Years between Standardization and Adoption
Drugeon continued by explaining that standards always come before new services but is difficult to know what broadcasters and service providers will do, but DVB can be an enabler. There can be a delay measured in years between the standardization and the adoption of new coding methods. The use of VVC, Drugeon said, ‘Makes 8K more realistic’ as a technology as the high bit rate needed for 8K with HEVC made the adoption less viable. VVC also enables 4K distribution using terrestrial broadcasting – and that’s a challenge using HEVC.
Finally, new coding methods have to be agnostic of the delivery mechanism with support for terrestrial, satellite, cable and streamed delivery paths. “VVC”, she said, “is a very obvious candidate for this”.
Turning to the question of how quickly new coding methods are adopted and Drugeon said that she feels that adoption of VVC is happening faster than earlier generations. While typical MPEG generations are 10 years apart, HEVC came in 2013, but VVC in 2020, just seven years apart so already on a faster trajectory.
Drugeon confirmed that the coding efficiency of VVC is one of the compelling features for DVB and the versatility to handle many different video formats. There are four receiver and Dash-player conformance points for VVC:
- Up to 4K standard frame rate with HDR
- Up to 8K standard frame rate with HDR
- Up to 4K high frame rate (HFR) with HDR
- Up to 8K high frame rate with HDR
The final 8K with HFR point is only interesting with VVC because it’s very difficult to do with HEVC. Drugeon clarified that HDR is now ‘a must have’ and VVC is ‘the first codec where 10 bit is the obvious format’ for broadcasters who have wanted to eliminate banding etc from 8 bit formats for a long time. 10 bit also enables HDR and it is more easily supported if receivers can accept 10 bits.
VVC Allows a High Level of 8K Quality
The efficiency of VVC allows an excellent level of subjective quality at 8K when content is delivered over a legacy broadcast structure – for example over a 40Mbps multiplex. It can also be used to deliver five 4K streams to be delivered within a DVB-T multiplex which is not possible with HEVC which would be limited to three if you want to meet the required quality for broadcast services.
In terms of streaming there are also some coding efficiency gains from the content aware encoding that allows changes within a video sequence to match the resolution to the content using reference picture sampling, something really new in VVC, Drugeon added. There are other options for personalization and other accecibility services in VVC using sub-pictures.
The DVB commercial requirement process identified at least a 30% improvement in efficiency to make VVC worthwhile, with 40% as desirable and VVC can achieve that and even up to 50%.
In conclusion, Drugeon said that the specification is published and available but DVB also provides materials for verification and validation (V&V). Streams are available for testing and development. Other facilities including checking are also available. In general terms, DVB is following the activities of MPEG which can provide new encoding systems. Bitrate savings will continue to drive the demand for novel technologies.
You can view the full interview here.
