Video: What’s the Deal with LL-HLS?

Low latency streaming was moving forward without Apple’s help – but they’ve published their specification now, so what does that mean for the community efforts that were already underway and, in some places, in use?

Apple is responsible for HLS, the most prevalent protocol for streaming video online today. In itself, it’s a great success story as HLS was ideal for its time. It relied on HTTP which was a tried and trusted technology of the day, but the fact it was file-based instead of a stream pushed from the origin was a key factor in its wide adoption.

As life has moved on and demands have moved from “I’d love to see some video – any video – on the internet!” to “Why is my HD stream arriving after my flat mate’s TV’s?” we see that HLS isn’t quite up to the task of low-latency delivery. Using pure HLS as originally specified, a latency of less than 20 seconds was an achievement.

Various methods were, therefore, employed to improve HLS. These ideas included cutting the duration of each piece of the video, introducing HTTP 1.1’s Chunked Transfer Encoding, early announcement of chunks and many others. Using these, and other, techniques, Low Latency HLS (LHLS) was able to deliver streams of 9 down to 4 seconds.

Come WWDC this year, Apple announced their specification on achieving low latency streaming which the community is calling ALHLS (Apple Low-latency HLS). There are notable differences in Apple’s approach to that already adopted by the community at large. Given the estimated 1.4 billion active iOS devices and the fact that Apple will use adherence to this specification to certify apps as ‘low latency’, this is something that the community can’t ignore.

Zac Shenker from Comcast explains some of this backstory and helps us unravel what this means for us all. Zac first explains what LHS is and then goes into detail on Apple’s version which includes interesting, mandatory, elements like using HTTP/2. Using HTTP/2 and the newer QUIC (which will become effectively HTTP/3) is very tempting for streaming applications but it requires work both on the server and the player side. Recent tests using QUIC have been, when taken as a whole, inconclusive in terms of working out whether this it has a positive or a negative impact on streaming performance; experiments have shown both results.

The talk is a detailed look at the large array of requirements in this specification. The conclusion is a general surprise at the amount of ‘moving parts’ given there is both significant work to be done on the server as well as the player. The server will have to remember state and due to the use of HTTP/2, it’s not clear that the very small playlist.m3u8 files can be served from a playlist-optimised CDN separately from the video as is often the case today.

There’s a whole heap of difference between serving a flood of large files and delivering a small, though continually updated, file to thousands of endpoints. As such, CDNs currently optimised separately for the text playlists and the media files they serve. They may even be delivered by totally separate infrastructures.

Zac explains why this changes with LL-HLS both in terms of separation but also in the frequency of updating the playlist files. He goes on to explore the other open questions like how easy it will be to integrate Server-Side Ad Insertion (SSAI) and even the appetite for adoption of HTTP/2.

Watch now!
Speaker

Zac Shenker Zac Shenker
Director of Engineering, Video Experience & Optimization,
CBS Interactive

Webinar: Implementing broadcaster addressable TV using HbbTV

HbbTV combines over-the-air TV with internet-delivered services which viewers see as a single, seamless service. HbbTV – which stands for Hybrid Broadcast Broadband TV – is a standardised way to deliver internet-enhanced over-the-air television to homes.

Date: Tuesday 16th July, 14:00 BST / 15:00 CEST

Now on version 2.0.1, HbbTV has been adopted around the world. The UK has the Freeview Play live and on-demand service based on HbbTV 2.0, delivered over satellite. New Zealand and Australia also have a Freeview-labelled service. Turkey and Saudi Arabia have services on HbbTV and Finland has been on air sine 2013 with HbbTV.

This webinar looks at what’s new in 2.0.1 and focusses on the possibilities of targeted advertising, highlighting the RTL Group’s world first swapping over-the-air ads for internet-delivered adverts.

This webcast will discuss:

  • The benefits of a standards-based ad insertion solution for the TV and device market
  • Market penetration of HbbTV devices that support IP-into-broadcast content substitution, including free-to-air hybrid set-top boxes, smart TVs and connected TV streaming devices
  • Technology capabilities within the HbbTV 2.0.1 standard, including how to implement HbbTV-enabled addressable TV
  • The rationale for including HbbTV ad insertion on devices that already include broadcaster OTT apps
  • Compatibility and interoperability between HbbTV and the broadcast backoffice and associated ad-tech
  • Efforts to include HbbTV ad insertion in the new HbbTV-TA (Targeted Advertising) standard

Register now!

Speakers

Henry Rivero Henry Rivero
VP Advanced Advertising & Innovation,
RTL Group
Frode Hernes Frode Hernes
SVP of Product Management,
Vewd
Leon Siotis Leon Siotis
GM Revenue Europe.
SpotX
John Moulding John Moulding
Editor-in-Chief
VideoNet

Video: 10 Common Mistakes and How to Avoid Them

A great way to end the week: From Channel Four’s Richard Davidson-Houston, 10 common mistakes made by online streaming services.

Richard’s advice covers a wide range of organisational biases and assumptions which may seem right at the time, but aren’t. The overall theme is to not understate the power and importance of online streaming, even within a traditional broadcaster and offers advice on how to fight your corner and ensure that the service you’re working for or are creating gets the attention it deserves.

From identifying irreversible decisions to not losing patience with intractable problems, Richard highlights the warning signs of going the wrong direction and provides some advice to help move forward.

Speakers

Richard Davidson-Houston Richard Davidson-Houston
Head of All Four,
Channel Four

Video: How to Identify Real-World Playout Options

There are so many ways to stream video, how can you find the one that suits you best? Weighing up the pros and cons in this talk is Robert Reindhardt from videoRx.

Taking each of the main protocols in turn, Robert explains the prevalence of each technology from HLS and DASH through to WebRTC and even Websockets. Commenting on each from his personal experience of implementing each with clients, we build up a picture of when the best situations to use each of them.

Speakers

Robert Reinhardt Robert Reinhardt
CTO,
videoRX