Search Results for: RIST

Video: 2019 What did I miss? – Introducing Reliable Internet Streaming Transport

Posted on by Russell Trafford-Jones

By far the most visited video of 2019 was the Merrick Ackermans’ review of RIST first release. RIST, the Reliable Internet Stream Transport protocol, aims to be an interoperable protocol allowing even lossy networks to be used for mission-critical broadcast contribution. Using RIST can change a bade internet link into a reliable circuit for live programme material, so it’s quite a game changer in terms of cost for links.

An increasing amount of broadcast video is travelling over the public internet which is currently enabled by SRT, Zixi and other protocols. Here, Merrick Ackermans explains the new RIST specification which aims to allow interoperable internet-based video contribution. RIST, which stands for Reliable Internet Stream Transport, ensures reliable transmission of video and other data over lossy networks. This enables broadcast-grade contribution at a much lower cost as well as a number of other benefits.

Many of the protocols which do similar are based on ARQ (Automatic Repeat-reQuest) which, as you can read on wikipedia, allows for recovery of lost data. This is the core functionality needed to bring unreliable or lossy connections into the realm of usable for broadcast contribution. Indeed, RIST is an interesting merging of technologies from around the industry. Many people use Zixi, SRT, and VideoFlow all of which can allow safe contribution of media. Safe meaning it gets to the other end intact and un-corrupted. However, if your encoder only supports Zixi and you use it to deliver to a decoder which only supports SRT, it’s not going to work out. The industry as accepted that these formats should be reconciled into a shared standard. This is RIST.

File-based workflows are mainly based on TCP (Transmission Control Protocol) although, notably, some file transfer service just as Aspera are based on UDP where packet recovery, not unlike RIST, is managed as part of the the protocol. This is unlike web sites where all data is transferred using TCP which sends an acknowledgement for each packet which arrives. Whilst this is great for ensuring files are uncorrupted, it can impact arrival times which can lead to live media being corrupted.

RIST is being created by the VSF – the Video Standards Forum – who were key in introducing VS-03 and VS-04 into the AIMS group on which SMPTE ST 2022-6 was then based. So their move now into a specification for reliable transmission of media over the internet has many anticipating great things. At the point that this talk was given the simple profile has been formed. Whist Merrick gives the details, it’s worth pointing out that this doesn’t include intrinsic encryption. It can, of course, be delivered over a separately encrypted tunnel, but an intrinsic part of SRT is the security that is provided from within the protocol.

Despite Zixi, a proprietary solution, and Haivision’s open source SRT being in competition, they are both part of the VSF working group creating RIST along with VideoFlow. This is because they see the benefit of having a widely accepted, interoperable method of exchanging media data. This can’t be achieved by any single company alone but can benefit all players in the market.

This talk remains true for the simple profile which just aims to recover packets. The main protocol, as opposed to ‘simple’, has since been released and you can hear about it in a separate video here. This protocol adds FEC, encryption and other aspects. Those who are familiar with the basics may whoosh to start there.

Speaker

Merrick Ackermans Merrick Ackermans
Chair,
VSF RIST Activity Group

Video: 2019 What did I miss? HDR Formats and Trends

Posted on by Russell Trafford-Jones

The second most popular video of 2019 looked at HDR. A long promised format which routinely wows spectators at conferences and shops a like is increasingly seen, albeit tentatively, in the wild. For instance, this Christmas UK viewers were able to watch HDR Premiership football in HDR with Amazon Prime, but only a third of the matches benefitted from the format. Whilst there are many reasons for this, many of them due to commercial and practical reasons rather than technical reasons, this is an important part of the story.

Brian Alvarez from Amazon Prime Video goes into detail on the background and practicalities of HDR in this talk given at the Video Tech Seattle meet up in August, part of the world-wide movement of streaming video engineers who meet to openly swap ideas and experiences in making streaming work. We are left with a not only understanding HDR better, but with a great insight into the state of the consumer market – who can watch HDR and in what format – as well as who’s transmitting HDR.

Read more about the video or just hit play below!

If you want to start from the beginning on HDR, check out the other videos on the topic. HDR relies on both the understanding of how people see, the way we describe colour and light, how we implement it and how theworkflows are modified to suit. Fortunately, you’re already at the one place that brings all this together! Explore, learn and enjoy.

Speaker

Brian Alvarez Brian Alvarez
Principal Product Manager,
Amazon Prime Video

Video: Wide Area Facilities Interconnect with SMPTE ST 2110

Posted on by Russell Trafford-Jones

Adoption of SMPTE’s 2110 suite of standards for transport of professional media is increasing with broadcasters increasingly choosing it for use within their broadcast facility. Andy Rayner takes the stage at SMPTE 2019 to discuss the work being undertaken to manage using ST 2110 between facilities. In order to do this, he looks at how to manage the data out of the facility, the potential use of JPEG-XS, timing and control.

Long established practices of using path protection and FEC are already catered for with ST 2022-7 for seamless path protection and ST 2022-5. New to 2110 is the ability to send the separate essences bundled together in a virtual trunk. This has the benefit of avoiding streams being split up during transport and hence potentially suffering different delays. It also helps with FEC efficiency and allows transport of other types of traffic.

Timing is key for ST 2110 which is why it natively uses Precision Timing Protocol, PTP which has been formalised for use in broadcast under ST 2059. Andy highlights the problem of reconciling timing at the far end but also the ‘missed opportunity’ that the timing will usually get regenerated therefore the time of media ingest is lost. This may change over the next year.

The creation of ST 2110-22 includes, for the first time, compressed media into ST 2110. Andy mentions that JPEG XS can be used – and is already being deployed. Control is the next topic with Andy focussing on the secure sharing of NMOS IS-04 & 05 between facilities covering registration, control and the security needed.

The talk ends with questions on FEC Latency, RIST and potential downsides of GRE trunking.

Watch now!
Speaker

Andy Rayner Andy Rayner
Chief Technologist,
Nevion

Video: How CBC/Radio-Canada Tested Media-over-IP Devices to Build its New Facility

Posted on by Russell Trafford-Jones

Moving video production to IP has been ongoing for over 5 years using both SMPTE ST 2022-6 and now ST-2110 but we’re still in the ‘Early Adopter’ phase, explains the Willem Vermost speaking at SMPTE 2019. Willem is the EBU topic lead for the transition to IP-based studios and he is tracking the upcoming projects with public broadcasters.

Willem talks about what’s motivating these Early Adopters. In general, he explains, they have a building move project and they are faced, as CBC (Canadian Broadcasting Corporation) was, with being the last to install an extensive SDI infrastructure – and be stuck with that for 7, 10 or more years to come – or the to be one of the first to use IP. Increasingly, they can’t justify the SDI workflow and IP, for all its risks and uncertainties, is the way forward.

CBC/Radio Canada needs to be ‘on air’ in 2020 so they put in a place a risk mitigation plan to test all the equipment before putting it in. Willem outlines what this test plan looks like and what it covers: AES67, ST 2110-40,-7, -30-, -20, EBU r148 security etc. Testing was also brought up by the BBC’s Mark Patrick when he discussed his work in bring in the BBC’s Cardiff Square building on-air. They found that automated testing was key in project delivery so that testing was quick and consistent to ensure that software/firmware patches were correctly accepted into the project.

Willem talks us through the EBU’s famous Technology Pyramid which shows to what extent each of the technologies on which media-over-IP requires has been defined and adopted by the industry. It shows that while the media aspect has been successfully deployed, there is a lot to do in, for example, security.

Difficulties arose due to different interpretations of standards. To aid in diagnosis of such issues, the LIST project has created a 2110 analysis tool and other related tools. This is created within the EBU and Willem highlights some key parts of what it does. He then shows how that connects in with the automated test programs and explains the underlying structure of how the software is built.

The talk finishes with mention of the JT-NM test plan, a summary and questions lead by Arista’s Gerard Phillips.

Watch now!
Speakers

Willem Vermost Willem Vermost
Senior IP Media Technology Architect
Topic Lead, Transition to IP-based Studios
EBU
Gerard Phillips Moderator: Gerard Phillips
Systems Engineer,
Arista