Video: Encoding and packaging for DVB-I services

There are many ways of achieving a hybrid of OTT-delivered and broadcast-delivered content, but they are not necessarily interoperable. DVB aims to solve the interoperability issue, along with the problem of service discovery with DVB-I. This specification was developed to bring linear TV over the internet up to the standard of traditional broadcast in terms of both video quality and user experience.

DVB-I supports any device with a suitable internet connection and media player, including TV sets, smartphones, tablets and media streaming devices. The medium itself can still be satellite, cable or DTT, but services are encapsulated in IP. Where both broadband and broadcast connections are available, devices can present an integrated list of services and content, combining both streamed and broadcast services.

DVB-I standard relies on three components developed separately within DVB: the low latency operation, multicast streaming and advanced service discovery. In this webinar, Rufael Mekuria from Unified Streaming focuses on low latency distributed workflow for encoding and packaging.

 

The process starts with an ABR (adaptive bit rate) encoder responsible for producing streams with multiple bit rates and clear segmentation – this allows clients to automatically choose the best video quality depending on available bandwidth. Next step is packaging where streaming manifests are added and content encryption is applied, then data is distributed through origin servers and CDNs.

Rufael explains that low latency mode is based on an enhancement to the DVB-DASH streaming specification known as DVB Bluebook A168. This incorporates the chunked transfer encoding of the MPEG CMAF (Common Media Application Format), developed to enable co-existence between the two principle flavors of adaptive bit rate streaming: HLS and DASH. Chunked transfer encoding is a compromise between segment size and encoding efficiency (shorter segments make it harder for encoders to work efficiently). The encoder splits the segments into groups of frames none of which requires a frame from a later group to enable decoding. The DASH packager then puts each group of frames into a CMAF chunk and pushes it to the CDN. DVB claims this approach can cut end-to-end stream latency from a typical 20-30 seconds down to 3-4 seconds.

The other topics covered are: encryption (exhanging key parameters using CPIX), content insertion, metadata, supplemental descriptors, TTML subitles and MPD proxy.

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Download the slides.

Speaker

Rufael Mekuria Rufael Mekuria
Head of Research & Standardization
Unified Streaming

Webinar: Codecs, standards and UHD formats – where is the industry headed?

Now Available On Demand
UHD transmissions have been available for many years now and form a growing, albeit slow-growing, percentage of channels available. The fact that major players such as Sky and BT Sports in the UK, NBCUniversal and the ailing DirecTV in the US, see fit to broadcast sports in UHD shows that the technology is trusted and mature. But given the prevalence of 4K in films from Netflix, Apple TV+ streaming is actually the largest delivery mechanism for 4K/UHD video into the home.

Following on from last week’s DVB webinar, now available on demand, this webinar from the DVB Project replaces what would have been part of the DVB World 2020 conference and looks at the work that’s gone into getting UHD to were it is now in terms of developing HEVC (also known as H.265), integrating it into broadcast standards plus getting manufacturer support. It then finishes by looking at the successor to HEVC – VVC (Versatile Video Codec)


The host, Ben Swchwarz from the Ultra HD Forum, first introduces Ralf Schaefer who explores the work that was done in order to make UHD for distribution a reality. He’ll do this by looking at the specifications and standards that were created in order to get us where we are today before looking ahead to see what may come next.

Yvonne Thomas from the UK’s Digital TV Group is next and will follow on from Ben by looking at codecs for video and audio. HEVC is seen as the go-to codec for UHD distribution. As the uncompressed bitrate for UHD is often 12Gbps, HEVC’s higher compression ratio compared to AVC and relatively wide adoption makes it a good choice for wide dissemination of a signal. But UHD is more than just video. With UHD and 4K services usually carrying sports or films, ‘next generation audio‘ is really important. Yvonne looks at the video and audio aspects of delivering HEVC and the devices that need to receive it.

Finally we look at VVC, also known as H.266, the successor to HEVC, also known as H.265. ATEME’s Sassan Pejhan gives us a look into why VVC was created, where it currently is within MPEG standardisation and what it aims to achieve in terms of compression. VVC has been covered previously on The Broadcast Knowledge in dedicated talks such as ‘VVC, EVC, LCEVC, WTF?’, ‘VVC Standard on the Final Stretch’, and AV1/VVC Update.

No Registration Necessary!

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Speakers

Ben Schwarz Ben Schwarz
Communication Working Group Chair,
Ultra HD Forum
Ralf Schaefer Ralf Schaefer
VP Standards R&I
InterDigital Inc.
Yvonne Thomas Yvonne Thomas
Strategic Technologist
DTG (Digital TV Group)
Sassan Pejhan Sassan Pejhan
VP Technology,
ATEME

Webinar: Multicast ABR opens the door to a new DVB era

Now available on demand

With video delivery constituting the majority of traffic, it’s clear there’s a big market for it. ON the internet, this is done with unicast streaming where for each receiver, the stream source has to send another stream. The way this has been implemented using HTTP allows for a very natural system, allied Adaptive Bit Rate (ABR), which means that every when your network capacity is constrained (by the network itself or bandwidth contention), you can still get a picture just at a lower bit rate.

But when extrapolating this system linear television, we find that large audience place massive demands on the originating infrastructure. This load on the infrastructure drives its architects to implement a lot of redundancy making it expensive to run. Within a broadcaster, such loads would be dealt with by multicast traffic but on the internet, Multicast is not enabled. For an IPTV system where each employee had access via a program on their PC and/or a set-top-box on their desk, the video would be sent by multicast meaning that it is the network that was providing the duplication of the streams to each endpoint, not the source.

By combining existing media encoding and packaging formats with the efficiency of point-to-multipoint distribution to the edge of IP-based access networks, it is possible to design a system for linear media distribution that is both efficient and scalable to very large audiences, while remaining technically compatible with the largest possible set of already-deployed end user equipment.

This webinar by Guillaume Bichot which is in place of his talk at the cancelled DVB World 2020 event explains DVB’s approach to doing thus that; combining multicast ordination of content with delivery of an ABR feed, called DVB-mABR.

Video broadcast has been digitised since it’s initial broadcasts in the 30s, and more than once. In Europe, we have seen IP carriage (IPTV) services and most recently the hybrid approach where broadband access is merged into transmitted content with the aim of delivering a unified service to the viewer called HbbTV. Multicast ABR (mABR) defines the carriage of Adaptive Bit Rate video formats and protocols over a broadcast/multicast feed. Guillaume explains the mABR architecture and then looks at the deployment possibilities and what the future might hold.

mABR comprises a multicast server at the video headend. This server/transcaster, receives standard ABR feeds and then encapsulates it into multicast before sending. The decoder does the opposite, removing any multicast headers revealing the ABR underneath. It’s not uncommon for mABR to be combined with HTTP unicast allowing the unicast to pick up the less popular channels but for the main services to benefit from multicast.

Guillaume explores these topics plus whether mABR saves bit rate, how it’s deployed and how it can change in the future to keep up with viewers’ requirements.

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Speaker

Guillaume Bichot Guillaume Bichot
Principal Engineer, Head of Exploration
Broadpeak

Webinar: HDR Dynamic Mapping

HDR broadcast is on the rise, as we saw from the increased number of ways to watch this week’s Super Bowl in HDR, but SDR will be with us for a long time. Not only will services have to move seamlessly between SDR and HDR services, but there is a technique that allows HDR itself to be dynamically adjusted to better match the display its on.

Introduced in July 2019, content can now be more accurately represented on any specific display, particularly lower end TVs. Dynamic Mapping (DM), is applies to PQ-10 which is the 10-bit version of Dolby’s Perceptual Quantizer HDR format standardised under SMPTE ST-2084. Because HLG (ARIB STV-B67) works differently, it doesn’t need dynamic mapping. Dynamic Metadata to support this function is defined as SMPTE ST 2094-10, -40 and also as part of ETSI TS 103 433-2.

Stitching all of this together and helping us navigate delivering the best HDR is Dolby’s Jason Power and Virginie Drugeon from Panasonic in this webinar organised by DVB.

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Speakers

Virginie Drugeon Virginie Drugeon
Senior Engineer for Digital TV Standardisation, Panasonic
Chair, DVB TM-AVC Group
Jason Power Jason Power
Senior Director, Commercial Partnerships and Standards, Dolby Laboratories
Chair, DVB CM-AVC Group