How to watch (and where to find) the World Cup in 4k UHD on BBC iPlayer in the UK

The BBC is running the UK’s first live 4K UHD HDR broadcast trial for the Russian 2018 World Cup.

It’s broadcast via the BBC iPlayer app directly on compatible smart TVs, The BBC do have a list of compatible TVs, but this isn’t a complete list.

Due to constraints in live encoding of UHD material, there are less renditions generated for live UHD content compared to the previous trial of non linear (Blue Planet 2) content. This means that there is only one true 4k rendition available, 3840x2160p at 50fps at a bitrate of 36Mbit/s. The BBC’s blog post has more technical information, including information on other renditions at lower resolutions.

You’re going to need at least a 40Mb internet connection to watch in UHD, but ideally more – especially if your TV is connected by Wi-Fi, which for many people will struggle to provide a consistent enough connection to support that – especially if you’ve got lots of devices connected or have a crowded wifi spectrum where you live.

So, can I watch in the World Cup in UHD 4k?

The first thing to do is find out if your TV is compatible. You can check the list here, but the best way to check is to see if the UHD test loop is available to you. The UHD test loop is currently broadcasting around 10 minutes of coverage of an FA Cup fixture.

You can access it by opening the BBC iPlayer app on your smart TV. You need to do this directly on your TV (or a Roku device, which appears to be the only supported external device – but it does not support HLG HDR) – things like Nvidia shield, Games Consoles or Fire TV sticks aren’t supported.

Once you’re in the iPlayer app, go across to settings and pick the “try new features” option. If at the bottom of the list you see a “UHD Test Loop” option, your TV is supported for UHD content. If you only see standard and beta, then unfortunately your TV is not supported.

How do I tune in to the 4k broadcast?

Once the BBC’s World Cup Match of the Day program starts on BBC1 (or whatever other channel they’re showing it) it will take a few minutes for the option to appear on iPlayer. This has ranged between 1 minute and 5 minutes for the 3 games that have aired so far.

You want to select the home tab of BBC iPlayer. If you’re too early, you can just keep pressing select on the home tab to make it refresh without having to restart the app.

Once available, the first panel of the home tab will show the UHD program, as shown in the image below of this morning’s France vs Australia game.

BBC iPlayer Home UHD Programme

Once it’s there, you can select the programme and it will give you the option to watch in UHD (or HD if you want… but that’s not why were here!)

BBC iPlayer UHD viewing options

Why does the BBC iPlayer Ultra HD World Cup feed keep buffering?

In my experience, there is usually at least one or two periods of buffering in every game, no matter how strong your connection is and if you’re wired. These are usually within the first few minutes of you tuning into the broadcast, and are likely to something to do with the BBC’s CDNs stabilising the number of people connected – as these buffering issues seem to affect everyone watching at the same time (at least anecdotally based on asking friends watching in UHD)

I’m on a fibre to the premises 200Mbps connection with purely gigabit cabling and a very powerful router handling everything, which means I’m in the fortunate position of knowing any buffering issues aren’t related to my home equipment, and must be either BT’s (or BBC’s) network, or the iPlayer servers.

That said, if you get persistent buffering it’s likely caused by one of two things.

1. Your internet connection isn’t fast enough to support such a high bitrate.

Because The BBC are broadcasting in 50fps (which is the right call for UHD content – the smooth fluid video is an important part of the UHD HDR experience), you’ll need at least double the bandwidth of what streaming 4K UHD content on Netflix or Amazon would require.

There’s also a less significant overhead of a few hundred kilobits per second by the fact live UHD HEVC encoders are less efficient than offline encoders which helps contribute to the bandwidth requirement.

So while the BBC say you need at least 40Mbps, if you’re on a line near you’re going to need to make sure other people aren’t doing anything on the internet or you’ll going to have issues.

2. You’re trying to use Wi-Fi which isn’t strong enough to support such a high bitrate.

Wi-Fi signal quality and speed varies drastically across different devices and environment, and the vast majority of issues if you’re connected by Wi-Fi will be related to that. If you can, switch to wired.Most ISP provided Wi-Fi routers aren’t very good, and definitely aren’t capable of supporting as many devices as most homes have along with a UHD stream.

How much bandwidth will watching a World Cup game in UHD consume?

I ran some tests during the first game shown in UHD yesterday, and it used a little over 42GB – that’s the complete UHD program from start to finish, including build up and wrap up. Some games have a longer presentation so will use a bit more.

Because iPlayer uses DVB-DASH (a form of MPEG-DASH), the video/audio transport stream is downloaded in 5 (or maybe 10 – it’s hard to know as it’s encrypted!) second chunks. This means that if you have a faster connection, these chunks will download as fast as possible. In my case, they download at around 80Mbit/s meaning that it is only downloading video for ~2.5 seconds out of every 5.

World Cup UHD bandwidth profile

Is the whole programme native 4K UHD?

Because of the AR (Augmented reality) aspects in the studio, all the presentation is shot in 1080p, and then upscaled at the OB truck (which is Timeline TV’s UHD2)

The host broadcast feed (or “world feed”) is native 4K UHD HDR – though not HLG HDR. It is converted to HLG as part of the broadcast output, so any live pictures from the stadium are native 4K UHD, but any BBC studio replays of previous games, or the current game you’re watching aren’t native.

This is particularly noticeable when the BBC show slow motion clips, which are 1080p slowed down and then unconverted to 2160p50, which after watching 50fps coverage is clearly noticeable.

Why is the picture so dark?

One of the perks of using HDR is the expanded colour space provided by the BT.2020 profile and the wider brightness range of HLG (1,000 nits) is that you will see a much more accurate representation of what the camera sees.

This means you’ll see much brighter colours, and more vivid differences between bright areas and shadows – this is very clear in today’s France vs Australia game as the sun was shining, but in yesterday’s games where it wasn’t, the picture did look much darker than we’re used to with SDR HD content.

If this is a big problem for you, you can adjust your TVs settings to increase the brightness yourself – but know that what you’re seeing is more accurate.

The following images (sorry about the shadows from my big windows!) shows the clarity provided by HDR where stadium casts shadows on the pitch and crowd.

How does the picture get to us, are they using multicast?

Whilst obviously being redundant, the main feed is brought back to us via IP, and then the BBC stream it to us via DVB-DASH, a form of HTTP Dynamic streaming based on MPEG-DASH.

A question I had when this was announced was whether the BBC will be using multicast to reduce strain, but it seems this isn’t the case. While BT TV uses multicast for it’s own services (including UHD) it’s carried outside of the public internet on their own network.

In theory it would be possible for iPlayer to use multicast, and I’m sure many ISPs would like this – it would require specific implementation by each ISP to make it work, which then makes it hard to test and probably specifically limited to the ISPs own hardware.

BT’s peak network throughput (that we know…) was 10.37 Tbps back in April. If the BBC allow 50,000 people to watch the UHD feed, that would generate 1.8 Tbps of data, almost 20% of BT’s entire peak traffic load, and that is why this is being run as a trial – it’s possible the UK’s internet infrastructure simply wouldn’t be able to cope.

That said, it doesn’t appear that all the UHD slots have been filled for any games so far, so it might not be as popular as expected – or the BBC have more slots than expected. I suspect for the quarter/semi/final things could be busier.

Off topic, but why isn’t The BBC World Cup Russia 2018 VR app working?

This wasn’t quite worthy of it’s own blog post, but in case anyone at the BBC actually reads this, I wanted to note there is an issue with the VR app if you’re on a IPv6 connection.

There appears to be an IPv6 network misconfiguration somewhere along the chain which means you can’t currently watch if your network supports IPv6. Turning off IPv6 (or switching to a mobile network which almost certainly won’t support IPv6) works.

UPDATE: It looks like someone has fixed this now, as it’s working for today’s games!


Broadcasting Sky Sky Q

Sky Q Formula One UHD Failed Recordings

This morning was the first live qualifying of Formula One available in Ultra HD on Sky Q, and it’s looking like it’s caused issues for lots of people.

There are reports on Twitter and Sky’s forums of numerous issues – “Part Recorded” or “Failed” for Qualifying this morning. Other people report green screens, artefacts and blocky pictures.

Let’s run down what I think went wrong.

Sunday 26th 04:30am BST (Race Show): Gulp. My box went into eco mode at 2:45am BST when it should have stayed awake in order to record the race show at 4:30am. Thankfully I manually woke up in time to start the Sky Q box and record again manually.

This likely means that many folk’s UHD recordings of the F1 Australian Grand Prix would have failed. Not sure if this bug is related to yesterday morning’s failures – I cancelled my race recording and rescheduled them yesterday, but maybe there is a bug with eco mode ignoring recording times, or maybe it’s a DST issue given the clocks changed.

Either way, it likely needs a software update to fix, and I doubt they’ll be able to get that through QA in time for China in 2 weeks.

Here’s the power profile (all times GMT)

Saturday 25th 11:30am (Qualifying): It looks like the most prevalent error is a ~30m partial recording of Practice 3, then Qualifying shows “Failed”. I found someone on twitter, (Thanks @crcaterham!) who had the issue and got the PVR data from the API. He says that P3’s status is “RECORDED” – this suggests the box actually thought the 30 minutes it recorded was the whole program. Then Qualifying has no error code and just shows “FAILED”.

This now looks to be related to the changes in scheduling Sky made this week. Potentially there’s a bug in the EPG where if the “schedule” is changed, it doesn’t update the start time, and so the recording fails.

If you setup your UHD recordings after Sky changed the formatting of the programmes earlier this week, or if you cancelled and re-setup the recordings after, you didn’t have this issue. Because of this, it’s probably wise to cancel your race recordings from Recordings > Scheduled, and re-configure them, otherwise your race recording might suffer from the same fate!

Broadcasting Sky Sky Q Tech

Sky Q Missing Thumbnails

22nd March Edit: Version 4 of the EPG rolled out today to all users. This changes the way the data is loaded from UDP to TCP, and should fix this bug.

There’s a common ‘bug’ with Sky Q that results in people seeing empty blue squares where the thumbnails should be.

I’ve tried to help folks on Sky’s own forum with this issue, but my post got deleted – presumably because I was guiding people on how to get information from their boxes via the Q App API. Whoops.

Anyway, this issue comes about because while some of the Sky Q guide content is loaded over a nice sensible HTTP TCP connection, they use extensively use UDP (as discussed yesterday) to request and receive data for the guide panels, and this is inherently unreliable.

Broadcasting Sky Sky Q Tech

Sky Q UPnP, REST and WebSocket API interfaces

It’s been a few years since we got into digging around Sky+HD’s UPnP control protocol, but having recently updated to Sky Q, there are a few changes that break the way we were talking to the box.

Backwards Compatibility

The Sky Q box contains pretty much the same UPnP advertised control system as Sky+HD, and includes a couple of new endpoints (service nodes) to do things that don’t seem too interesting. A “Pairing” service node and a “BasicManagement” service node.

There is one potentially breaking change though. The SkyServe2 service node now provides the service type urn:schemas-nds-com:service:SkyPlay:2 as well as the SkyControl2 service node. If you register a listener, or make any calls against the SkyServe2 node, you won’t get any useful data. This means if you’re using a library like dalhundal/sky-plus-hd, you’ll need to skip over the response from SkyServe2, and just use SkyControl2 like before.


iPhone 6S Launch Reservation Stock

It’s over 24 hours since the iPhone 6S became available for pre-ordering or reservation at your local Apple Store come the 25th February, and it’s safe to say Apple have way more of these things than they did the iPhone 6 last fall, as you can still make a reservation for a few models and pick it up on launch day – at any UK Apple store.

Last year, I threw together a little availability chart for UK availability to give an at-a-glace view into the way these things work. It worked okay, but it polled Apple’s reservation endpoints “live” (with a 60 second cache) and didn’t really allow me to build any trends out of it.

This year, for the Apple Watch launch, I threw a database onto the backend, and started storing the responses so I could process how quickly models sold out when the reservation APIs went live, and much more importantly, make some pretty graphs. Obviously, Ahrendts ruined that plan, but I was ready for this launch.

Onto the graphs…