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Video: VVC, EVC, LCEVC, WTF? – An update on the next hot codecs from MPEG

Posted on 30th September 2019 by Russell Trafford-Jones

The next-gen codecs are on their way: VVC, EVC, LCEVC but, given we’re still getting AV1 up and running, why do we need them and when will they be ready?

MPEG are working hard on 3 new video codecs, one in conjunction with the ITU, so Christian Feldmann from Bitmovin is here to explain what each does, the target market, whether it will cost money and when the standard will be finalised.

VVC – Versatile Video Codec – is a fully featured video codec being worked on as a successor to H.265, indeed the ITU call it H.266. MPEG call it MPEG-I Part 3. Christian explains the ways this codec is outperforming its peers including a flexible block partitioning system, motion prediction which can overlap neighbouring macroblocks and triangle prediction to name but three.

EVC is the Essential Video Codec which, intriguingly, offers a baseline which is free to use and a main profile which requires licences. The thinking here is that if you have licensing issues, you have the option of just turning off that feature which could five you extra leverage in patent discussions.

Finally, LCEVC – the Low Complexity Essential Video Codec allows for enhancement layers to be added on top of existing bitstreams. This can allow UHD to be used where only HD was possible before due to being able to share decoding between the ASIC and CPU, for example.

These all have different use cases which Christian explains well, plus he brings some test results along showing the percentage improvement over today’s HEVC encoding.

Watch now!
Speaker

Christian Feldmann
Codec Engineer,
Bitmovin

Video: Red and Blue, or Purple; Your IP Media Network, Your Way

Posted on 4th September 2019 by Adam K

Leaf & spine networks have started taking over data centres in the last few years. It’s no secret that people prefer scale-out over scale-up solutions and you can see a similar approach in ST 2110 networks, when large monolithic video switches are replaced with smaller leaf and spine switches.

Leaf and spine refers to networks where a number of main, high throughput switches link to a number of smaller switches. These smaller switches tend to be aggregators and offer the promise of cheaper ports delivered closer to your equipment. The alternative to leaf & spine is monolithic switches which do have their merits, but are certainly not always the right choice.

To provide non-blocking switching in leaf & spine networks you need an SDN controller that orchestrates media flows. Advances in SDN capabilities have led to the emergence of “Purple” network architectures. In this video Gerard Phillips from Arista shows how it differs from a “Red/Blue” architecture, how path diversity is maintained and how ST 2110 IP live production or playout applications could benefit from it.

It’s important to be aware of the different uses of Layer 2 vs Layer 3:

• Layer 3 have distributed IGMP management since PIM is used on each router to route multicast traffic, so there is no more flooding network with unnecessary traffic. This type of network works well with high bit rate video multicasts, but as IGMP is not bandwidth aware, it’s best to use an SDN system for flow orchestration.

Gerard then looks at resilience:

Using 2022-7 seamless switching (plus a robust monitoring system that can provide quick, accurate information to resolve the issue)
Choosing quality components (switches, NOS, fibres etc.)
Providing redundancy (redundant PSU, fans, fabric modules etc., redundant links between switches, ensuring that routing protocol or SDN can use these “spares”)
Dividing up failure domains
Using leaf and spine architecture (routing around failed components with SDN)
Using resilient IP protocols (BGP, ECMP)

The talk finishes up discussing the pros and cons of the different architectures available:

Monolithic systems which are non-blocking, but have a wide failure domain
Monolithic – expansion toward spine and leaf with SDN for non-blocking switching
Leaf & spine with air-gapped Red and Blue networks
Leaf & spine hybrid with Purple switches connected to both Red and Blue spines to support single homed devices
Leaf & spine Purple. Here, red and blue flows are connected to physically separate switches, but the switches are not identified as red and blue anymore. This is a converged network and an SDN controller is required to provide diverse paths flows to go to two different spines.

You can download the slides from here.

Watch now!

Speaker

Gerard Phillips
Systems Engineer
Arista Networks

Webinar: Cloud Ingest

Posted on 28th August 2019 by Russell Trafford-Jones

RIST and SRT are gaining more and more traction as they solve the reliability question over internet contribution. Promising cheaper costs than dedicated circuits, so much of our life uses the internet, it seems logical that it helps connect broadcasts as much as it does video conferences.

SRT and RIST are both protocols which allow streaming of video and other media over networks. If any packets go missing then the receiver will let the sender know and the sender will retransmit the missing data. All being well, these missing packets will arrive in time and no one will know that any data loss took place.

SRT was started by Haivision and is now an open source collaboration with a public repository and slack workspace. It goes beyond simple retransmission and actually offers an encrypted link which is so important when it comes to sports and other high value content.

RIST is being developed by the Video Services Forum (VSF) and the specifcation TR-06 defines how it works. This is is released as a freely-available specification and implementations based on the first release were shown at IBC2018. For a video on RIST, check out this talk from Merrick Ackermans

The RIST working group comprises people from Haivision, Zixi, NetInsight and other companies many of whom also have similar technologies. So the question is why is RIST of so much interest and what are the differences and benefits to SRT?

This Webinar from Net Insight sets out to answer just this question as we’ll as looking to the future to see what is yet to come on the RIST roadmap.

Register now!
Speakers

	Love Thyresson Head of Internet Media Transport, Net Insight
	Alexander Sandström Head of Product Marketing & Co-chair of RIST Forum, Net Insight

Video: Bandwidth Prediction in Low-Latency Chunked Streaming

Posted on 19th August 2019 by Russell Trafford-Jones

How can we overcome one of the last, big, problems in making CMAF generally available: making ABR work properly.

ABR, Adaptive Bitrate is a technique which allows a video player to choose what bitrate video to download from a menu of several options. Typically, the highest bitrate will have the highest quality and/or resolution, with the smallest files being low resolution.

The reason a player needs to have the flexibility to choose the bitrate of the video is mainly due to changing network conditions. If someone else on your network starts watching some video, this may mean you can no longer download video quick enough to keep watching in full quality HD and you may need to switch down. If they stop, then you want your player to switch up again to make the most of the bitrate available.

Traditionally this is done fairly simply by measuring how long each chunk of the video takes to download. Simply put, if you download a file, it will come to you as quickly as it can. So measuring how long each video chunk takes to get to you gives you an idea of how much bandwidth is available; if it arrives very slowly, you know you are close to running out of bandwidth. But in low-latency streaming, your are receiving video as quickly as it is produced so it’s very hard to see any difference in download times and this breaks the ABR estimation.

Making ABR work for low-latency is the topic covered by Ali in this talk at Mile High Video 2019 where he presents some of the findings from his recently published paper which he co-authored with, among others, Bitmovin’s Christian Timmerer and which won the DASH-IF Excellence in DASH award.

He starts by explaining how players currently behave with low-latency ABR showing how they miss out on changing to higher/lower renditions. Then he looks at the differences on the server and for the player between non-low-latency and low-latency streams. This lays the foundation to discuss ACTE – ABR for Chunked Transfer Encoding.

ACTE is a method of analysing bandwidth with the assumption that some chunks will be delivered as fast as the network allows and some won’t be. The trick is detecting which chunks actually show the network speed and Ali explains how this is done and shows the results of their evaluation.

Watch now!

Speaker