Who's winning the Chromecast image war?

Internet video services are rushing to embrace Google's tiny streaming media stick, but which one delivers the goods in terms of picture quality?

There was a time when Australia was an internet video wasteland but now we're spoiled for choice -- especially if you own Google's $49 Chromecast and you're looking to enjoy online video on the big screen. Of course, as soon as you go large, any imperfections show up in the picture, and some video services fare better than others.

We’ve been able to screen mirror video content from Apple and Android devices for a while using streaming formats like AirPlay and Miracast, but they fall short of the Chromecast when it comes to picture quality. The reason for this is that they take mobile-quality video and upscale it to the big screen.

The Chromecast can do better than this. If you're streaming video from your computer, smartphone or tablet using a Chromecast-compatible service such as Quickflix or Netflix, the Chromecast makes a direct connection to the back-end server and pulls down TV-quality video. At this point the picture quality can improve considerably and your smartphone simply becomes a remote control.

Five-way shootout

To find out whose picture quality reigns supreme, we cued up Netflix, Quickflix, Foxtel Presto, Google Play and EzyFlix on a first-generation iPad mini -- linked to a Chromecast plugged into a 46-inch Sony Bravia. They were all reliant on a lowly 3 Mbps DSL connection (access to the NBN -- in any way, shape or form -- is still years away for many Australian homes).

Finding the same movie on every service is tough, especially as Presto's line-up continually changes depending on what's screening on Foxtel this month. Of the five services, Google Play seems the most reliable when it comes to finding the movie you want in your resolution of choice.

Things are further complicated by the fact that Quickflix and Foxtel Presto are only standard-def services, although Quickflix is preparing to make the leap to high-def in the next few months. For now you'll find a handful of HD movies in the Quickflix subscription library as a trial, but Quickflix hasn't drawn attention to them yet. Unfortunately they only stream in HD on the Xbox 360 and Xbox One, so you won't see the difference on the Chromecast at this stage. If you're prepared to pay extra, you'll also find a smattering of pay-per-view HD content on Quickflix, including Game of Thrones.

Standard-definition

The Adam Sandler comedy Click is on Netflix, Google Play, Quickflix, EzyFlix and Presto, although only the first two have it in HD. Netflix has an unfair advantage because it uses adaptive streaming which automatically improves the picture quality, if the bandwidth allows. Google Play is the pick of the bunch when you look at the other four services in SD -- all streamed from the internet rather than downloaded first. Quickflix is the most disappointing when it comes to picture quality.

But there's more to picture quality than just resolution -- you're also looking for compression artifacts, where the picture looks ‘blocky’ because it's skimped on detail. Fast-moving action and the fine detail of shimmering of smoke, fire or water are a torture test on this measure.

You can clearly see these imperfections in Click's swimming pool scene (about 7 minutes in). Quickflix and EzyFlix look blocky when the camera pans across the cheering crowd, as well as when Adam Sandler walks past the water and when his son climbs out of the pool. EzyFlix still looks slightly better than Quickflix.

You'll struggle to find compression artifacts during the same scenes when watching either Google Play or Presto, but people's faces look slightly sharper in Google Play, as do Adam Sandler and David Hasselhoff's suits in the previous scene. In fact, on our 3 Mbps DSL connection, on a 46-inch television, Google Play SD is barely distinguishable from Netflix in these scenes. A bigger television and/or faster connection would see Netflix rise above.

Of course, your mileage may vary here due to a range of factors which may be beyond your control. Quickflix is also in the process of a back-end HD upgrade which will include the iOS app, so it's a test that would be worth repeating later in the year.

High-definition

To give EzyFlix and Quickflix the chance to shine we looked for something they both offered in HD along with Netflix and Google Play. Such a search is complicated by the fact that some EzyFlix movies won't stream to the Chromecast due to rights deals -- which is infuriating when you're paying the same price.

Eventually we settled on Morgan Freeman's Olympus Has Fallen -- not because it's a great movie but simply because all but Quickflix offer it in HD and will stream it to the Chromecast. As for Quickflix, we pitted it against Google Play using Game of Thrones in HD.

A high-definition movie is unlikely to be affected by significant compression artifacts. Instead you need to look for murkiness in the shadows -- slight pixelation and blur, along with the loss of fine details. Sometimes the darkest shades of grey are crushed down to solid black, so objects like men in dark suits appear like slightly pixelated blobs and the wrinkles in their clothing are lost.

There's not a lot between Netflix, EzyFlix and Google Play, but look closely and Netflix comes out slightly ahead. Just past the 20-minute mark of Olympus Has Fallen, when the White House is attacked from the air, the President is rushed to a safe room by secret service men. The backs of their dark suits become pixelated in EzyFlix and Google Plus. Dylan McDermott's shiny grey suit looks blotchy as he walks through the foyer.

Each image has its strengths and weaknesses, but all up Netflix comes out in front with Google Play second and EzyFlix a close third. Google Play occasionally buffers on a 3 Mbps connection, while the others cope better.

We're splitting hairs at this point and you'll need an eye for detail to spot the difference between these three HD services. The imperfections are far less striking than in the SD pictures. The larger your television the easier it is to spot the blemishes, which are distracting if you've an eye for quality.

Next Quickflix and Google Play battled it out in Westeros, screening Season 4, Episode 1 of Game of Thrones in HD -- streamed, not downloaded. Google came out the clear winner. As Tywin Lannister melted down Ned Stark's valyrian sword in the opening scenes, Quickflix showed pixelation in the flames and smoke. Switching to Google Play saw the pixelation disappear.

So what’s the verdict?

Netflix takes the honours when it comes to Chromecast picture quality, thanks to its adaptive streaming. Of course, even if you do sneak into the US-only service, most of what you want to watch is missing.

Of the Australian services, Google Play is the winner both in terms of breadth of content and streaming quality in both standard and high definitions. We'll watch Quickflix's HD overhaul with interest, but right now if picture quality is your primary concern then Google Play is the pick of the bunch on the Chromecast.