Video: A paradigm shift in codec standards – MPEG-5 Part 2 LCEVC

LCEVC (Low Complexity Enhancement Video Coding) is a low-complexity encoder/decoder is in the process of standardisation as MPEG-5 Part 2. Instead of being an entirely new codec, LCEVC improves detail and sharpness of any base video codec (e.g., AVC, HEVC, AV1, EVC or VVC) while lowering the overall computational complexity expanding the range of devices that can access high quality and/or low-bitrate video.

The idea is to use a base codec at lower resolution and add additional layer of encoded residuals to correct artifacts. Details are encoded with directional decomposition transform using a very small matrix (2×2 or 4×4) which is efficient at preserving high frequencies. As LCEVC uses parallelized techniques to reconstruct the target resolution, it encodes video faster than a full resolution base encoder.

LCEVC allows for enhancement layers to be added on top of existing bitstreams, so for example UHD resolution can be used where only HD was possible before thanks to sharing decoding between the ASIC and CPU. LCEVC can be decoded via light software processing, and even via HTML5.

In this presentation Guido Meardi from V-Nova introduces LCEVC and answers a few imporant question including: is it suitable for very high quality / bitrates compression and will it work with future codecs. He also shows performance data and benchmarks for live and VoD streaming, illustrating the compression quality and encoding complexity benefits achievable with LCEVC as an enhancement to H.264, HEVC and AV1.

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Guido Meardi
CEO and Co-Founder
V-Nova Ltd.

Video: There and back again: reinventing UDP streaming with QUIC

QUIC is a encrypted transport protocol for increased performance compared to HTTP but will this help video streaming platforms? Often conflated with HTTP/3, QUIC is a UDP-based way evolution of HTTP/2 which, in turn, was a shake-up of the standard HTTP/1.1 delivery method of websites. HTTP/3 uses the same well-known security handshake from TLS 1.3 that is well adopted now in websites around the world to provide encryption by default. Importantly, it creates a connection between the two endpoints into which data streams are multiplexed. This prevents the need to constantly be negotiating new connections as found in HTTP/1.x so helping with speed and efficiency. These are known as QUIC streams.

QUIC streams provide reliable delivery, explains Lucas Pardue from Cloudflare, meaning it will recover packets when they are lost. Moreover, says Lucas, this is done in an extensible way with the standard specifying a basic model, but this is extensible. Indeed, the benefit of basing this technology on UDP is that changes can be done, programmatically, in user-space in lieu of the kernel changes that are typically needed for improved TCP handling on which HTTP/1.1, for example, is based.

QUIC hailed from a project of the same name created by Google which has been taken in by the IETF and, in the open community, honed and rounded into the QUIC we are hearing about today which is notably different from the original but maintaining the improvements proved in the first release. HTTP/3 is the syntax which is a development on from HTTP/2 which uses the QUIC transport protocol underneath or as Lucas would say, “HTTP/3 is the HTTP application mapping to the QUIC transport layer.” Lucas is heavily involved with in the IETF effort to standardise HTTP/3 and QUIC so he continues in this talk to explain how QUIC streams are managed, identified and used.

It’s clear that QUIC and HTTP/3 are being carefully created to be tools for future, unforeseen applications with clear knowledge that they have wide applicability. For that reason we are already seeing projects to add datagrams and RTP into the mix, to add multiparty or multicast. In many ways mimicking what we already have in our local networks. Putting them on QUIC can enable them to work on the internet and open up new ways of delivering streamed video.

The talk finishes with a nod to the fact that SRT and RIST also deliver many of the things QUIC delivers and Lucas leaves open the question of which will prosper in which segments of the broadcast market.

The Broadcast Knowledge has well over 500 talks/videos on many topics so to delve further into anything discussed above, just type into the search bar on the right. Or, for those who like URLs, just add your search query to the end of this URL

Lucas has already written in detail about his work and what HTTP 3 is on his Cloudflare blog post.

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Lucas Pardue Lucas Pardue
Senior Software Engineer,

Video: The challenges of deploying Apple’s Low Latency HLS In Real Life

HLS has taken the world by storm since its first release 10 years ago. Capitalising on the already widely understood and deployed technologise already underpinning websites at the time, it brought with it great scalability and the ability to seamlessly move between different bitrate streams to help deal with varying network performance (and computer performance!). In the beginning, streaming latency wasn’t a big deal, but with multi-million pound sports events being routinely streamed, this has changed and is one of the biggest challenges for streaming media now.

Low-Latency HLS (LL-HLS) is Apple’s way of bringing down latency to be comparable with broadcast television for those live broadcast where immediacy really matters. The release of LL-HLS came as a blow to the community-driven moves to deliver lower latency and, indeed, to adoption of MPEG-DASH’s CMAF. But as more light was shone on the detail, the more questions arose in how this was actually going to work in practice.

Marina Kalkanis from M2A Media explains how they have been working with DAZN and Akamai to get LL-HLS working and what they are learning in this pilot project. Choosing the new segment sizes and how they are delivered is a key first step in ensuring low latency. M2A are testing 320ms sizes which means very frequent requests for playlists and quickly growing playlist files; both are issues which need to be managed.

Marina explains the use of playlist shortening, use of HTTP Push in HTTP2 to reduce latency, integration into the CDN and what the CDN is required to do. Marina finishes by explaining how they are conducting the testing and the status of the project.

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Marina Kalkanis Marina Kalkanis
M2A Media

Video: VVC – the Next-Next Gen Codec

VVC is a new standard going through MPEG standardisation which is being increasingly discussed. Dubbed the next, next-gen Codec, it promises to deliver many improvements over current Codecs.

Christian Feldmann from Bitmovin takes us through what’s new to help understand where the Codec is in its development, who is involved and how it’s going to achieve its aims. Covering also licenseing

There’s a lot of work to do, but anyone who has an interest in Codecs should take some time to understand the work which is going on.

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Christian Feldmann Christian Feldmann
Codec Engineer,