By Jacob Smith
This week, I am at the HbbTV Association plugfest in London to test out some of the new audio features that are made possible by the latest HbbTV specification.
The latest HbbTV spec, version 2.0.2, includes support for HDR video and next generation audio, offering a level of experience that was only previously possible via native OTT apps like Netflix and Disney+.
The HbbTV Association holds these plugfests regularly, and they provide a great opportunity for broadcasters, service providers, TV manufacturers and other stakeholders to get together and test that what has been specified on paper actually works – and that new services will work in a predictable way on receivers. They take place in various locations around Europe – this one was hosted in the great facilities of the DTG, the centre for UK digital TV responsible for the D-Book receiver specification.
Our focus this time is on testing some of the AC-4 next generation audio features that are included in HbbTV 2.0.2, and that are now starting to appear in European TVs. In particular, v2.0.2 means that broadcasters can use the AC-4 next generation audio that is shipping in most European UHDTVs not just for broadcast, but for broadband delivery too. That provides a path via broadband for delivering many interesting new features, including immersive 3D sound, enhanced accessibility features, and audio personalisation. This path is easy to implement, because it uses existing device capabilities in the field.
For broadband delivered HbbTV services, V2.0.2 enables receivers to identify that they are equipped with AC-4 decoding so that next generation audio content can be targeted at suitably equipped receivers.
We’re seeing a lot of interest from broadcasters in using personalisation aspects of AC-4, where the audio mix can be optimised to suit different viewer preferences or listening scenarios. For example, these can be used to offer a regular audio mix for normal listening and a dialogue-focussed mix for noisy environments, or two different audio mixes of a football game, with different commentators favouring the two teams. HbbTV v2.0.2 provides a means for the HbbTV app to select the audio mix – this is done using the existing HTML5 AudioTrack mechanism in the browser. So a key focus at the plugfest is to try out this new mechanism, and check that it is working on a variety of different browsers and TVs.
It is encouraging to see the progress that the industry is making with implementing these new features. It’ll be great to see services coming to market to take advantage of these new capabilities.
HbbTV can be attractive to broadcasters as a way to innovate services a faster, more flexible, and cost-effective way than traditional terrestrial broadcast. This includes the possibility of delivering services that are more immersive and personalised through the use of next generation audio (NGA).
TV models are now coming to market with interesting functionality for setting up trials and experimental deployments. There are opportunities to collaborate in order to ensure the functionality broadcasters’ need is implemented in future devices.
At the HbbTV Symposium in November 2019, there were demonstrations concerning how broadcasters can leverage HbbTV and Dolby AC-4 audio to deliver more engaging and individually tailored services, to mainstream European UHDTVs.
Demonstrations by Dolby and Vewd featured mainstream TV models from Panasonic and Vestel, offering immersive Dolby Atmos sound using the internal speakers of the TV. The rendering in the TVs created a 3D sound image with height, without the need for an external soundbar or home cinema system.
One novel aspect was the possibility to add streamed Dolby Atmos immersive audio to existing terrestrial linear broadcast services as a replacement for the normal stereo broadcast audio. As the immersive audio was streamed, it was not necessary to reconfigure the terrestrial multiplex with an extra audio bitstream. The immersive audio was delivered as an AC-4 bitstream via HbbTV, and synchronised with the broadcast video using the HbbTV v2 Media Synchronisation feature. A simple HbbTV app was used which allowed the user to substitute the broadcast stereo audio with the immersive streamed audio by pressing the blue button.
Using a Panasonic TV, these demonstrations also highlighted the ability to enhance dialogue clarity by boosting the dialogue level within the mix. This was controlled using the Dialogue Enhancement on/off user setting of the TV user interface.
Additionally, that existing TVs can support the overlay of app-generated sounds was also shown. This has many potential applications, including the provision of spoken remote control button sounds for the visually impaired (e.g. for ‘play’, ‘pause’, etc.). This is achieved while maintaining the full immersive sound experience over speakers and on the HDMI output.
Broadcasting faces new challenges, but also new opportunities. The internet has opened up the playing field for media delivery, enabling a whole new generation of content providers and media services beyond those of traditional broadcast. At the same time, this increasingly competitive landscape presents opportunities for broadcasters to deliver their unique content offerings in new ways, and to better engage with new and existing audiences.
New entrants and new technology have led to a wave of innovation for content discovery and recommendation, as well as for the viewing experience itself. Viewers are getting used to innovation after innovation at internet pace. Big broadcasters and global streaming players can afford to develop these new ideas for their services, but the smaller broadcaster trying to compete in the same space while maintaining identity and independence has difficult choices to make.
HbbTV (hybrid broadcast broadband TV) helps broadcasters address these challenges and capitalise on opportunities for new and enhanced services. It's an open standard that enables them to provide smart TV viewers with additional options and experiences in a scalable way, by allowing broadcasters to develop online apps and services that work with almost all brands of smart TVs.
Although it has its roots as a solution for interactive services, the latest version - HbbTV 2.02 - is of particular interest because it enables enhancement of the viewing experience without needing the significant infrastructure investments required for upgrading traditional broadcast networks.
The most immediate benefit to broadcasters is that HbbTV can now deliver ultra-high definition video and next-generation audio (NGA). This opens the path to delivering the same experiences as the big OTT providers' HDR and 3D audio. If a smart TV can play back such media, then HbbTV 2.0.2 makes these capabilities available to broadcasters.
Alongside higher-resolution content, HbbTV gives viewers more control over how they consume that content, including greater personalisation. This is most exciting with next-generation audio, or "NGA", which can carry multiple versions of high-quality audio simultaneously over one internet stream and lets the user personalise how they listen.
You may have seen demonstrations of how this can be used in sporting and entertainment events. Multiple commentator languages, trackside ambience, crowd noise, and even event radio chatter can be provided for the user to select and mix - and for some, the ability to remove commentary altogether is going to provide a 'you are there' experience worth the price of a new smart TV!
But Next Generation Audio offers benefits a lot broader than just source choice. NGA delivered via HbbTV can broaden service accessibility and engagement for a wide range of users. For instance, consider a viewer who finds music in a drama intrusive, masking the dialogue. With NGA, the viewer can choose the accessible experience from the same audio bitstream and adjust the balance between dialogue and music or sound effects to a comfortable level. This lets broadcasters make their content available to a wider audience.
The best part of all this is that broadcasters can start to build these sorts of capabilities now. The HbbTV 2.0.2 specifications already include the details of how to deliver NGA using AC-4 audio technology, and support for the necessary features is starting to appear in shipping TVs.
Most importantly for broadcasters, this approach makes economic sense, both in terms of the investment required and the efficiencies for leveraging your current infrastructure. It will work alongside your digital terrestrial or satellite broadcast chain and your existing streaming services, and can be introduced as you see fit.
If you're interested in HbbTV, here's a three-point checklist to start your journey:
* To find out how to create NGA content with AC-4, talk to us at Dolby. We're always keen to talk about content.
* Find someone internal or external to help with your app development process. Talk to people who've worked on HbbTV apps to set the scope of what you want to do.
* Come to an HbbTV interoperability event. You can see which HbbTV devices are coming to market, check how your app works with them to build confidence, and talk to your peers. They're a lot of fun and you'll learn a lot.
The future is full of promise and full of challenges. At Dolby we're ready to help you meet that future and succeed.
European culture is rich and complex, and the continent’s art embodies that. Franco-German TV channel ARTE, dedicated to presenting both traditional and modern cultural programming from across the creative spectrum, has quite a job on its hands. Its output must speak in different languages, while capturing the breadth of experience a sophisticated audience demands.
To meet those audience demands, ARTE is quickly adopting new video and audio technologies, as well as embracing the possibilities the internet offers broadcasters. One such advancement is ARTE enabling a pilot of its next-generation HbbTV platform with Dolby Vision and Dolby Atmos via Next Generation Audio Dolby AC-4 – three key developments that bring unrivalled flexibility, quality, and choice to programme makers, and a new consistency of experience to consumers.
HbbTV (Hybrid Broadcast Broadband TV) is a European standard that incorporates broadcast content with interactive services such as electronic programme guides and choice of audio tracks. Most smart TV models from major brands now support it; ARTE’s platform enables broader access and enriched interactive content using a new service based on the latest approved 2.0.2 HbbTV standard, supporting UHD in HDR as well as next generation audio.
Viewers will be able to access TV content in Dolby Atmos – via Dolby AC-4 – and Dolby Vision, for immersive viewing. This suite of experience-enhancing technologies is becoming more widely adopted by broadcasters and streaming services, and is praised by programme makers for delivering a more cinematic feel to dramas and documentaries. Channel owners also like the capability to include multiple language and subtitle options, as well as a choice of viewpoint and many accessibility enhancements.
HbbTV brings the flexibility of internet streaming services to broadcasters without impacting their existing distribution chains. As a standard, it removes the need for custom apps for different platforms, reducing development costs and increasing user acceptance by ensuring commonality without impacting flexibility or content quality. It allows consumers to make full use of HDR and Dolby Atmos capabilities already in many mainstream televisions – or other devices – and opens up the ability of Next Generation Audio Dolby AC-4 to bring exceptional spatial soundscapes and a plethora of choices to producers and consumers alike.
ARTE’s pilot platform supports a range of content format options, making it suitable for a wide viewership. It provides a range of reception options from top-of-the-line TVs and older sets. Formats available include Dolby Vision HDR (HEVC), HDR10 (HEVC), SDR (HEVC), Dolby Atmos (via Dolby AC-4), 5.1 (Dolby Digital Plus) and traditional – but still very popular – stereo.
Device makers and service operators can expect ARTE’s pilot platform to meet viewer expectations for modern, internet-connected viewing. In particular, advanced user interface designs and consistent, device-optimised playback on compatible smart TVs will make the experience of consuming content more satisfying.
Viewers in Germany can launch the pilot platform when watching via the Astra satellite service, while French audiences can use Fransat and Eutetsat’s Hot Bird 13°. Both countries will also carry it on DTTV. Many programmes are already available, such as those from German production house MedienKontor (GEO Reports: Nepal – In the Realm of Sounding Bowls; GEO Reports: The Neon Designers of Hong Kong) or by ZDF/ARTE (The Greatest Race).
With content creators, channel aggregators, distribution systems, set makers, and viewers now set up for the highest possible quality of programming on the most advanced interactive platforms, the future of television is now visible with exceptional clarity.
European national broadcasters
A major French tennis tournament streamed to mobile devices with immersive audio through Dolby AC-4.
RTVE and Cellnex Telecom’s permanent UHD DVB-T2 trial channel uses Dolby AC-4. RTVE broadcast the Change of the Royal Guard live from the Royal Palace in Dolby AC-4 and Dolby Vision.
European Broadcasting Union groundbreaking high frame rate UHD broadcast trial featured immersive and personalised audio experiences with Dolby AC-4.
Phoenix Model Market
Phoenix Model Market launched their first
next-generation television channel with Dolby AC-4.
WRAL-TV & NBC UNIVERSAL
WRAL-TV, NBC Universal, and NAB Showcase Next Gen TV
broadcasted Winter Olympic Games with Dolby AC-4.
NRJ conducted broadcast tests for UHD 4K, HDR and Dolby AC-4 over DTTV in Paris and other regions across France (as well as by satellite) on three DTTV channels over two weeks. The first service was in UHD 4K HDR HLG 50p (over 24 Mbps high-speed broadband), the second and third in HD+ 1080p50 HDR HLG at different, lower rates. NRJ combined each of these video flows with a stereophonic audio component coded in Dolby AC-4.
The purpose was to test the video quality over different encoding bitrates as well as the interoperability of video and audio flows with televisions available on the market. After these accomplishments, on the last day of the test, an immersive and multi-language flow was also successfully broadcast on channel 81 in AC-4 and Dolby Vision.
Now we know that as well as the video, many of the 2017 and 2018 TV models sold in France (LG, Samsung, Philips, etc.) are compatible with an AC-4 transmission, in stereo and in immersive or multiple language formats. Many 2019 television models will also support AC-4.
In December 2018, in the DVB-T2 multiplex trial the Spanish government made available to the broadcasters RTVE and Cellnex Telecom switched on AC-4, covering 5 major cities in Spain: Madrid, Barcelona, Sevilla, Malaga, and Santiago de Compostela.
This channel is on-air 24/7, featuring a loop of more than 6 hours of content in UHD with E-AC3 and AC-4 as the only audio codecs in the channel.
RTVE will keep expanding the number of hours of content available while Cellnex Telecom will work on expanding the coverage nationwide.
Dolby AC-4 is mentioned in an article by Stuart Thomson of Digital TV Europe about the status of Pearl TV’s Phoenix Model Market. Citing a spokesperson from Pearl TV, Stuart adds, "there had been a strongly positive consumer reaction to advanced audio features enabled by Dolby AC-4 audio."
Click HERE to read the full article.
A personalized audio experience test was performed with KPBS in San Diego.
Following the announcement of a successful test of an ATSC 3.0 standard component on Wednesday, yet another element of Next Gen TV has received a passing grade during a separate experiment. Verance Corporation and Dolby revealed they conducted a test in February with San Diego station KPBS on internet-delivered dialogue enhancement, a Next Gen TV personalized audio experience.
Using the Verance Aspect watermark and Dolby AC-4, the test demonstrated that the dialogue enhancement feature of the AC-4 can be delivered as a standalone audio stream over the internet and paired with video delivered through a live linear broadcast. The companies reported that the pairing was made with precise broadband audio and broadcast video synchronization, and delivered over all MVPD paths, including cable and satellite.
Click HERE to read the full article.
It’s April 2020. I’m sitting in front of my computer at home. I wasn’t supposed to be here over these last few weeks. Last month, the plan was to be at the European Broadcasting Union (EBU) in Geneva, collaborating with industry partners for one of the first workflow tests with the new sADM standard.
sADM is the serial version of the Audio Definition Model, an open format for professional interchange of next-generation audio (NGA) content. It’s interesting for us at Dolby as it promises to be a flexible, open format that broadcasters and other content creators can use to make and edit NGA content, prior to broadcast or streaming delivery using Dolby AC-4.
There was a lot to do. Our goal – prove the concept of an open, format-agnostic approach to NGA content creation, and show that this could work with AC-4 delivery to real consumer devices. The original aim was to assemble a full end to end workflow from OB audio production through to a transmission to consumer TVs and mobile devices. And then to test a variety of new use cases that next generation audio enables – for example, multi-language commentaries for sports broadcasts, and personalisation to improve dialogue clarity for dramas.
However, the real world doesn’t always conform to engineering requirements, not even those of the EBU. With the coronavirus crisis building and travel off the menu, the Geneva face to face meeting was cancelled, changing to a ‘virtual plugfest’ where we could conduct our own testing and share results. But as the testing deadline drew closer, the Dolby teams involved from Poland, the UK and the US progressively became subject to lockdown guidelines, and eventually all of us were working from home.
Fortunately, before lockdown we had a chance to build a broadcast chain in our office and to configure it for remote management. Even with this much-reduced test system, we were able to attempt four of the five originally planned tests.
Working offline did, of course, present new challenges. We were extremely grateful to our encoder partner Ateme, who ensured Dolby AC-4 passthrough in the video encoder worked well. They provided remote access to a video encoder, streaming its output live over the Internet back to us for validation. But how to validate playback without access to our receiver test lab? Fortunately, we could take advantage of the AC-4 decoding capability that is already in many UHDTVs in Europe – team members were able to validate AC-4 playback simply using their own home televisions.
The process was a testament to flexibility – not just of the technology but of the teams involved – that we pulled off this testing not just in this unexpected virtual way but while different parties were going into lockdown.
We all learned a lot. These tests will help to finalise ADM Profiles to assist future interoperability. We’re extremely grateful to the EBU for inviting us to participate and to all the industry partners that contributed. We hope that, before long, the live event calendar will be resuming and circumstances will allow us to put sADM into action in a real live broadcast trial.
Of course, when big events will be back is just another of the unknowns we’re all dealing with right now. However, we do know that Dolby and all our partners are making real progress in defining and testing the next generation of audio, ready for the opportunities ahead.
Even in the internet age, terrestrial broadcast TV remains the central source of entertainment and news for hundreds of millions of Europeans. While it continues to thrive, it is rapidly changing due to pressures on spectrum, consumer demand for more choice, and expectations of higher quality. Dolby’s AC-4 audio compression technology is ready to help broadcasters answer those challenges, and we are delighted to see the first full trial take to the air with Telewizja Polska (TVP).
We take a very active and partnership-driven role in the creation of new industry standards, so it’s satisfying to see AC4 go from a specification to a full TV service reaching an audience of over six million people.
Dolby’s office in Poland has worked closely with TVP and Emitel, the transmitter operator, to make AC-4 a seamless part of the broadcasting chain. With the country migrating to the new DVB-T2 standard over the next two years, AC-4 is a very good match for this next generation of terrestrial digital broadcasting. It uses less bandwidth than existing codecs, and has the ability to carry new features and services that improve the viewing experience. For example, viewers will be able, in the future, to not only select different languages or commentaries, but boost dialogue over background sound, improving accessibility for many.
To deploy a new audio codec on-air, one key step is to prepare the transmission workflow with the necessary encoding capabilities. This was made much easier in this case by leveraging AC-4 encoding built into ATEME’s TITAN Live encoder.
Testing began internally at TVP in 2018, with AC-4 coverage of the Poland v Lithuania pre-World Cup football match. Live events like this can benefit from the AC-4 system in many ways. Viewers can enjoy a full Dolby Atmos immersive sound experience, with the energy of the stadium all around. AC-4 also enables viewers to choose the audio experience they most enjoy – for example, with a favourite commentator, or no commentator at all. As broadcasters and viewers become accustomed to the potential, we expect to see many new services that capitalise on these unique live events to engage even further with viewers in new and exciting ways.
Getting there takes work, but we’re more than happy to help. For example, we worked with TVP to help test a range of TV sets currently on the Polish market for compatibility. Although our licensing system with set makers involves a testing and approval stage, nothing builds confidence like seeing – or in this case hearing – a new system work exactly as it will for the end consumers. We estimate that over 70 percent of new televisions shipping in Europe have AC-4 capabilities, so the compatible user base is large and growing rapidly, and it will continue to expand as people buy new sets compatible with the new broadcast standards.
TVP is initially using AC-4 for its Kultura HD arts channel, which carries concerts, documentaries, and other cultural events. TVP expects this programming will get the most critical appraisal from its discerning audience. The initial test comprises two transmitters in Krakow and Katowice covering some six million people. Expansion is already planned to reach the entire country.
Our experience with TVP and Emitel has been very positive, especially given the extremely challenging circumstances of 2020. TVP was originally considering AC-4 for introduction with future UHD 4K services, but as we worked with them it became apparent to them that there is enough immediate potential for it to be worth introducing sooner. The viewership seems happy with this first step.
With this live service up and running, we can say with confidence that the European terrestrial broadcast market is ready for AC-4. To learn more about using Dolby AC-4, please contact us.
The NorDig standards body, confirmed today that Dolby AC-4 has been officially added as well as the only next generation audio codec for the forthcoming NorDig specification v3.1.
The specification will require all HEVC enabled receivers (set top boxes and TVs) to support Next Generation Audio Dolby AC-4.
The specification will require all HEVC enabled receivers (set top boxes and TVs) to support Next Generation Audio Dolby AC-4.