Video: Sub-Second Live Streaming: Changing How Online Audiences Experience Live Events

There are two main modern approaches to low-latency live streaming, one is CMAF which used fragmented MP4s to allow frame by frame delivery of chunks of data. Similar to HLS, this is becoming a common ‘next step’ for companies already using HLS. Keeping the chunk size down reduces latency, but it remains doubtful if sub-second streaming is practical in real world situations.

Steve Miller Jones from Limelight explains the WebRTC solution to this problem. Being a protocol which is streamed from the source to the destination, this is capable of sub-second latency, too, and seems a better fit. Limelight differentiate themselves on offering a scalable WebRTC streaming service with Adaptive Bitrate (ABR). ABR is traditionally not available with WebRTC and Steve Miller Jones uses this as an example of where Limelight is helping this technology achieve its true potential.

Comparing and contrasting Limelight’s solution with HLS and CMAF, we can see the benefit of WebRTC and that it’s equally capable of supporting features like encryption, Geoblocking and the like.

Ultimately, the importance of latency and the scalability you require may be the biggest factor in deciding which way to go with your sub-second live streaming.

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Speakers

Steve Miller-Jones Steve Miller-Jones
VP Product Strategy,
Limelight Networks

Video: Securing NMOS Apps

The still-growing NMOS suite of specifications from AMWA defines ways in which your IP network can find and register new devices plugged in to it (e.g. camera, microphone etc.), manage their connections and control them. They fit neatly along side the SMPTE ST 2110 suite of standards which define the way that the essences (video, audio, metadata) are sent over networks intended for professional media.

As such, they are core to a network and as the market for uncompressed media products matures, the attention is on the details such as whether they scale and security.

In this talk, Simon Rankine from BBC R&D starts by explaining the objectives which means looking at the different aspects of security which is split into three; securing data transfer, ensuring data goes to the right place, ensuring only authorised people can act.

TLS, standing for Transport Layer Security, is the same protocol used for secure websites; those which start with https://. It is also referred to by the name of the protocol it replaced, SSL. Given the NMOS APIs are sent over HTTP, TLS is a perfect match for the use case. TLS provides not only the ability to encrypt the connection but also provides the basis for certificate exchange which allows us trust that the data is being sent to the right place. Simon then covers ciphers and TLS versions before talking about certificate management.

This talk was given at the IP Showcase at NAB 2019.

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Speaker

Simon Rankine Simon Rankine
Research Engineer,
BBC R&D

Video: AAC Demystified: How the AAC audio codec works and how to make sense of all its crazy profiles.

The title says it all! Alex Converse speaks here at the San Fancisco Video Tech meet up while he was working at Google discussing the ins and outs of AAC – and since he implemented an AAC decoder himself, he should know a thing or two about it.

Sure enough, Alex delivers by talking about the different version of AAA that have been around since MPEG 2 AAC through to the high efficiency AACs we have seen more recently.

Walking through the AAC Encoder block diagram we look at each of the different sections from sampling, MDCT (a type of Fourier transform) to psychoacoustic processing, stereo processing and more.

We then start to look at the syntax for the way the streams are structured which brings us in to understanding the AAC channel modes, and the enhanced mechanisms for encoding and processing used by the later versions of AAC including HE-AAC V2.

Alex finished with quick look at low delay codecs and a Q&A.

A great, detailed, overview of AAC. Ideal for developers and those who need to fully understand audio.

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Speaker

Alex Converse Alex Converse
Senior Software Engineer,
Twitch

Video: CEDIA Talk: ATSC 3.0 is HERE – Why It Matters to You


That last in the current series of ATSC 3.0 posts. This one is a light, but useful talk which aims to introduce people to ATSC 3.0 calling out the features and differences.

Michael, showing off his colour bars jacket, explains how ATSC 3.0 came about and how ATSC 2.0 never came to pass and ‘is on a witness protection program’. He then explains the differences between ATSC 1.0 and 3.0, discussing the fact its IP based and capable of UHD and HDR amongst other things.

The important question is why is it better and we see the modulation scheme is an improvement (note Michael says ATSC 3.0 is based on QAM; it actually based on OFDM.)

The talk finishes talking about what ATSC 3.0 isn’t and implementation details and the frequency repack which is happening in the US.

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Speaker

Michael Heiss Michael Heiss
Principal Consultant,
M. Heiss Consulting