The future of 4K video streaming is bright but we still need Ultra HD Blu-ray
Whilst we’re waiting for an announcement on the future of a 4K Blu-ray format and the broadcasters get into gear, the only real way to get at any significant amount of Ultra HD content is via Netflix.
The UHD TVs released in 2014 by Sony, Samsung and LG all have this capability and Panasonic promises the upcoming AX900 series will also carry the 4K Netflix app, after rather dropping the ball with the AX800/802.
There are some provisos, of course, the biggest of which is the need for a minimum broadband speed of around 16Mbps and ideally you’ll want more like 20Mbps to ensure you’ll not have to endure buffering issues. Those kinds of speeds are readily obtainable for many, however, and the network infrastructure can only improve.
This is all well and good but there are questions over just how much benefit 4K can bring when streamed, at what are considered relatively low bitrates. There is four times the resolution information compared to 1080p (Full HD) and when you consider a typical Blu-ray will replay at somewhere in the 30-40Mbps range there’s a gap that needs to be filled in the compression techniques.
Step forwards HEVC (High Efficiency Video Coding), aka H.265, which uses around 50% of the bitrate of the video codecs typically used on Blu-ray discs. Still, that would suggest you would want 60-70Mbps to view 4K at its best.
Lighting is just that bit more nuanced with 4K
The Netflix 4K catalogue is not large but if you’re a fan of either/or House of Cards and Breaking Bad, you’ve got a fair bit to go at with both series of the Netflix original, HoC, and all five series of Breaking Bad available to stream via the Netflix service. As we love both, this task has proved no hardship but to keep comparisons simple, we’re concentrating on the second series of House of Cards, as that’s what we’ve spent most time with.
Our tests were carried out with the Samsung 48HU7500, Sony 55X8505 and Samsung 65HU8200 to look at a spread of different screen sizes. Our default seating position is 7.5 feet away from the centre of the screen but we’ll make mention of any time we had to move closer to perform an analysis. Each display was calibrated to the Rec.709 standard, to ensure a level playing field and whilst gleaning hard scientific evidence is difficult we took great pains, and many scene re-runs, to provide the most studied comparisons feasible.
Our main areas of interest where in perceptible resolution differences and motion handling but were also looking out for any picture anomalies, such as posterisation (colour banding) and compression artefacts as well – particularly in the case of the streamed content.
For reference, our internet connection is via fibre optic cable from Virgin Media and is billed as 30Mbps, although according to various speed tests, we normally receive closer to 20Mbps. To ensure maximum local bandwidth, pretty much every other device was disconnected from the router, prior to viewing and that’s no mean task. The Blu-ray player used was Panasonic BDT-300 which we know produces a flawless 1080p24 output.
Our Modus Operandi altered somewhat during the process from what we set out to do, in order to take account of the difficulty in switching between the TVs’ Netflix app and the source input for the Blu-ray player but thankfully the processors in the TVs used were of sufficient speed to ensure that the delay was only brief. This did mean that we had to do more back and forth than originally hoped but we wanted to be as certain, as possible, images were locked in the mind. One of LG’s webOS/Smart+ TVs would have been a boon here, with their instant switching capabilities, but you can’t have everything in life!
So let’s start right at the beginning of Season 2 with the scene where Frank and Clare are jogging through the park in the dead of night, illuminated only by streetlamps. Before the protagonists enter shot, we had a good chance to analyse the scene, taking particular note of the texture of the pathway, various very small objects on the grass and how the light travelled out through the lamps themselves. In terms of detail, on all of the screens at our usual sitting position, there was no discernable resolution difference between the two. Moving to within around 5 feet and the image looked that bit sharper, from the Netflix stream, on the 65-inch HU8200 but you’d have to get closer still with the smaller TVs to see it. Make of that what you will.
No surprises there, really, as images shot at night time often aren’t as detailed as those shot in more favourable light but we could see a slight enhancement in shadow detail with Netflix 4K when the Underwoods came to the foreground. It’s a pore here and a tiny hair there but there was that momentary sense the Ultra HD source was holding an advantage, albeit a very slight one. However, it took at least five re-runs from each source to reach that conclusion, so it’s fair to say it’s not something that slapped us in the face
The gilding of the picture frames provided some marginal upgrade with the Netflix service
Since we see them so often and they do contain some cracking shots, the beginning and end credits for the series make for good subject matter. We once remarked, after our first taste of Netflix 4K that tarmac had never looked so good. There’s a depth of field shot taken upwards from Pennsylvania Avenue, next to the Newseum Building in Washington DC, which is beautifully done and very detailed and we thought we may see Netflix edge ahead with this one but, in all honesty, they were practically identical. Again, stick your nose up against and the 4K content stays sharper but there was nothing else in it in terms of detail and resolution.
Moving in to Frank’s Office and a meeting with his successor as House Majority Whip, Jackie Sharp, and we have opportunity to assess things in a more well lit environment. It has to be said that House of Cards is an incredibly well shot piece of television, captured on RED Epic cameras with close attention to detail, framing and setting and it’s a match for most movies out there so it looked stellar through both sources in this scene. The textures in the clothing, upholstery and skin abound but we can score a marginal advantage to Netflix for the odd rogue bit of weave being visible on the right shoulder of Frank's charcoal grey suit. You might laugh but the gilded picture frames on the walls behind Frank and Jackie also had a bit more texture and pazazz from the streamed source. Again, it took repeated and very close scrutiny to be at least fairly certain but we think there’s a small upgrade with Netflix here.
During the same scene, there’s a sequence where Jackie follows Frank to his desk to look at his PC. Watching the Blu-ray, as the new Whip passes by a window, there is clearly some judder visible with the curtains. This is an expected phenomena with material shot in the, relatively low, film cadence of twenty four frames per second but we were surprised to see the exact same thing replicated with the Netflix stream on the Samsung TVs. Here we had an opportunity for a spot of science and we took our Klein K10 Colorimeter to the screen to measure the refresh rate, which was topping out at 96Hz. That suggests the source is 24p and each frame is replicated four times to avoid flicker. This is something we consider a plus although down the line we expect Ultra HD framerates will increase – and for some content that’s likely a good thing – but it’s refreshing to know a streaming service is willing to remain faithful to the source. Of course, a lower framerate helps keep the bandwidth down, too, but let’s be generous to Netflix.
We went through a number of other scenes (lots) where we thought we might see the 4K content hold some resolution advantages over the Blu-ray but there were, in all honesty, very few. In fact, we’ve now re-watched the entire second season of HoC (plus a few episodes from Breaking Bad) and the overriding feeling was that it was with the handling of nuanced lighting effects where 4k marginally held sway. This helps increase the dynamic range and texture of images, whilst giving just a shade more naturalness at the same time but we’re again right at that margins of perceptibility at first glances.
Make-up artists will need to step up to the plate
The one scene where we thought there is a fairly clear 4K advantage comes toward the end of the first episode and is incredibly pivotal to the series. We won’t spoil but it involves Frank and journalist, Zoe, in a subway. The pair rendezvous on a platform and as Zoe approaches Frank she comes to rest up against a wall. Now, actress Kate Mara is undeniably beautiful but nobody’s perfect and she does, like us all, have the odd skin blemish. It’s not that you can’t see them on the Blu-ray but we could far more easily distinguish the texture of the concealer make up (in this case, used in vain) from the Netflix stream. Is that a good or bad thing? We’re not sure but the Resolution Revolution obviously calls for the make-up artists to up their games.Audio is definitely advantage Blu-ray, right now.Putting the ‘A’ in to AVForums, we turn to the question of audio and here it is most definitely advantage Blu-ray. The disc carries a DTS-HD MA surround track which is probably as good as the video, in quality terms, and highly atmospheric. The best the Netflix apps can muster is 5.1 Dolby Digital Plus, which is by no means bad but doesn’t have the same dynamic range as the ‘lossless’ format. How much of an ‘audio guy’ you are will of course be a factor here but even someone more focussed on the video will likely note the lip-sync issues with the Netflix app. The Samsung TVs have a normal default delay of 60ms built in for their audio output but that ramps up to 240ms when you enter the app, which is close but still a few milliseconds out. The only way to currently get around this slight issue is with use of an external amp with finer delay settings but not everyone will have that facility so it’s up to the manufacturers to build better mechanisms into their TVs.
So, is 4K Netflix an upgrade over Blu-ray? Well, you win ever so slightly on video and you lose a bit on audio but it’s looking more and more like we need a physical format to drive home the resolution advantages, whilst maintaining lossless audio codecs. But that’s ignoring the vital factors of price and convenience. As part of a £6.99 monthly subscription, you can access both seasons of House of Cards and all five of Breaking Bad, which is quite simply ridiculous value and the costs of the equivalent Blu-rays would be magnitudes greater.
The apps built in to the TVs are also superb, incredibly fast both to load and reach full resolution and the user experience is undeniably first class. Of course, there needs to be more content and it will need to be updated regularly but if this is the future of streaming video services, it’s an incredibly rosy one. Even in its infancy, the HEVC codec is holding up very well indeed and didn’t get any of the banding or compression issues we were kind of expecting. Don’t get us wrong, we still want 4K Blu-ray but this will keep us very happy in the meantime – or at least until we’ve finished going through all the episodes of Breaking Bad. Again.
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