Tech Analysis: Next-generation game broadcasting • Articles • Eurogamer.net
It's a game-changer. No longer the preserve of those who invest in specialist capture equipment, the arrival of Xbox One and PlayStation 4 allows every new console owner to record and broadcast gameplay, with Nvidia joining the party with the recent release of its ShadowPlay system for PC. All of this is happening in parallel with the meteoric rise of streaming services like Twitch, which along with the continued success of YouTube offers a robust platform for anyone to transmit their gameplay to the world, whether livestreaming or simply sharing video.
In this article, we'll be taking a look at the new options available to gamers in sharing their gameplay, with a focus on the facilities offered by the Xbox One and PlayStation 4. PC also gets a look-in too owing to the recent release of a seriously impressive piece of tech: Nvidia's recent ShadowPlay update allows gamers to save off high-quality 1080p60 clips while they play - an entirely free upgrade to anyone who owns one of its graphics cards based on the Kepler architecture, virtually any GTX 6xx or GTX 7xx desktop graphics card.
So let's look at the basics of how these systems work. All of them are based on the same principle: video is compressed into the h.264 format on the fly courtesy of built-in hardware encoders. This is custom silicon built for the task at hand - in the case of Xbox One and PlayStation 4, this has precisely no effect on the performance of the system, while in the case of ShadowPlay, we're looking at an estimated three to five per cent drop in the performance of the GPU - not bad at all considering the quality of the assets produced. All of these systems offer the ability to save off HD gameplay for easy sharing: Xbox One allows for distribution of video via Xbox Live or SkyDrive, while PlayStation 4 opts for Facebook. ShadowPlay simply dumps off video files onto your hard drive - with the gamer deciding from there what to do with them. Think of that as the 'power' option for advanced users.
Live-streaming takes things to the next level - you're not just spooling out video, but sharing it with the world in real time via services like Twitch or Ustream. Up until now, live-streaming has been the preserve of those connecting up their hardware to PCs with capture cards, running broadcasting software like X-Split or Open Broadcaster. The software here usually compresses video using the brilliant open-source encoder x264, with the stream uploaded to the provider who then serves the exact same video to viewers. This is an interesting way of doing things in that it allows the player to define the quality of the video they are transmitting in terms of bandwidth, resolution and frame-rate - a level of flexibility that Xbox One and PlayStation 4 can't really offer.
ShadowPlay is set for a live-streaming update early next year, but what we saw at a recent Nvidia press event was impressive, with high-quality 720p60 video beamed out via Twitch, complete with the ability to embed a picture-in-picture webcam feed, simultaneously muxing in microphone audio. The current ShadowPlay beta doesn't support it though, and rather disappointingly, neither does Xbox One (it's due to be introduced next year). This leaves PlayStation 4 in the clear as the only gaming platform to fully integrate live-streaming at a hardware level. As strategic advantages go, that's priceless.
One thing to get straight right away is that PlayStation 4's implementation is very much a mainstream, easy-to-use system that is not going to be a replacement for the hardcore with their capture card/PC set-ups. It's seemingly designed to work on as many connections as possible, meaning that the streaming options are configured not to push the limits of your broadband too much, even if you're on a state-of-the-art fibre connection. The very highest bandwidth level available is a mere 1.5mbps, some way short of the 3-4mbps that we routinely see from enthusiast PC Twitch users.
PlayStation 4 has four live-streaming quality levels: low, medium, high and the optimistically entitled best. We ran the same section of Assassin's Creed 4 gameplay through Twitch and grabbed the resultant streams for analysis. Here you can see two distinct quality strata: 960x540 and 640x360, with simple tweaks made to the video bandwidth. It's basic, entry-level stuff, but generally speaking it seems to do the job. It is a real shame that audio is so severely compromised on low and medium though - 32kbps just doesn't cut it, not surprisingly sounding quite horrible. Also disappointing is the lack of 720p support, not to mention the ability to spend a bit more bandwidth on the quality of the stream.
Overall then, PlayStation 4 streaming is pretty basic and we couldn't help but wish for some higher quality options - and dare we say it, better-quality encoding - but the important thing is that it gets the job done. There's also support for the PlayStation Camera, allowing you to include talking heads in your stream, while audio can be muxed in via the DualShock 4 mic or the camera itself. Audience interaction isn't bad either - during live-streaming, the gameplay window is considerably reduced, but you do get to see the comments being added by users - and you can reply using text too by using the Share button, although this does pause the game, which is not ideal.