VSF

Video: Performance Measurement Study of RIST

Posted on by Russell Trafford-Jones


RIST solves a problem by transforming unmanaged networks into reliable paths for video contribution. This comes amidst increasing interest in using the public internet to contribute video and audio. This is partly because it is cheaper than dedicated data circuits, partly that the internet is increasingly accessible from many locations making it convenient, but also when feeding cloud-based streaming platforms, the internet is, by definition, part of the signal path.

Packet loss and packet delay are common on the internet and there are only two ways to compensate for them: One is to use Forward Error Correction (FEC) which will permanently increase your bandwidth by up to 25% so that your receiver can calculate which packets were missing and re-insert them. Or your receiver can ask for the packets to be sent again.
RIST joins a number of other protocols to use the re-request method of adding resilience to streams which has the benefit of only increasing the bandwidth needed when re-requests are needed.

In this talk, Ciro Noronha from Cobalt Digital, explains that RIST is an attempt to create an interoperable protocol for reliable live streaming – which works with any RTP stream. Protocols like SRT and Zixi are, to one extent or another, proprietary – although it should be noted that SRT is an open source protocol and hence should have a base-level of interoperability. RIST takes interoperability one stage further and is seeking to create a specification, the first of which is TR-06-1 also known as ‘Simple Profile’.

We then see the basics of how the protocol works and how it uses RTCP for singling. Further more RIST’s support for bonding is explored and the impact of packet reordering on stream performance.

The talk finishes with a look to what’s to come, in particular encryption, which is an important area that SRT currently offers over and above reliable transport.
Watch now!

To dig into SRT, check out this talk from Chris Michaels
For more on RIST, have a look at Kieran Kunhya’s talk and Rick Ackerman’s introduction to RIST.

Speaker

Ciro Noronha Ciro Noronha
Director of Technology, Compression Systems,
Cobalt Digital

Video: AMWA NMOS State of Play

Posted on by Russell Trafford-Jones

With all the talk of the SMPTE ST 2110 standards suite, it’s sometimes forgotten that it only deals with content. If you want a working system, you’ll need to do a few more things – find new devices on the network, work out what they can do, control them, guarantee the bandwidth and often deal with metadata that arrives separately like tallies.

This is what the AMWA NMOS specifications do. Peter Brightwell and Thomas Edwards have been heavily involved in creating them and in this video lead us through what each one does and how they are used.

Watch now!

Speakers

Peter Brightwell Peter Brightwell
Lead Engineer,
BBC R&D
Thomas Edwards Thomas Edwards
VP Engineering & Development
Fox NEO

Video: AMWA NMOS IS-04 and IS-05 Scalability and Performance

Posted on by Russell Trafford-Jones

AMWA’s discovery and registration protocols IS-04 and IS-05 play a big role in making IP systems usable, allowing the system to easily identify new kit when it’s plugged in and understand its capabilities. However, deploying such systems at scale should give anyone pause for thought – how scalable are they? How does the system recover after a network outage? Clearly we wouldn’t want the system to be brought down by the administrative burden.

Rob Porter, from Sony Europe Ltd., has done the research and presents it here at the VSF’s IP Showcase at the 2018 IBC.

Rob gives a brief overview of the two specifications, describing their APIs and the open source nature of them. He then goes on to explain how he emulated this large number of devices and what he found.

Finally, Rob wraps up the session by explaining how he optimised network-loss recovery times and summarises best practices.

Watch now!

Speaker

Rob Porter Rob Porter
Project Manager – Advanced Technology Team,
Sony Europe Limited

Video: RIST – Introducing Reliable Internet Streaming Transport

Posted on by Russell Trafford-Jones

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.

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.

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.

Watch now!
Download the presentation

Speaker

Merrick Ackermans Merrick Ackermans
Chair,
VSF RIST Activity Group