Blog Post

The technology behind Google+ Hangouts

Stay on Top of Enterprise Technology Trends

Get updates impacting your industry from our GigaOm Research Community
Join the Community!

Ever since Google (s GOOG) started to roll out its Google+ project on Tuesday, many of its users have been particularly excited about its group video chat service Hangouts. I agree, but not just because it’s fun and easy to use. The real kicker is the technology that powers the service. Even in its infancy, Hangouts is an interesting cloud service. But in the not-so-distant future, it could evolve into a standards-based video conferencing solution that runs natively in many browsers and on a whole range of devices.

Google has been quiet about its plans for Hangouts, and hasn’t revealed all that much about some of the components powering the service either. However, there have been some key developments in recent months that indicate what makes Hangouts work and where things are going:

The cloud

Making video chat work at scale can require a lot of resources, which is why there has been a movement towards peer-to-peer (P2P) solutions to offload video and signaling traffic between the clients involved. Skype (s MSFT) makes use of P2P for that very reason, as does Chatroulette. However, P2P can introduce latency, which can be especially bothersome if you chat with 10 people at a time. That’s why Google went down a different route for Hangout.

“To support Hangouts, we built an all-new standards-based cloud video conferencing platform,” explained Google Real-time Communications Tech Lead Justin Uberti in a blog post on Tuesday. He added that Hangouts uses a client-server model which “leverages the power of Google’s infrastructure.”

Browser integration

Hangouts currently requires you to download the same plugin that also powers video chat within Google Talk. However, Google is working on making both Hangouts and Google Talk itself work in the browser, without the need for any plugins. This will be done in part through a new framework for realtime communications (read: text, voice and video chat) dubbed WebRTC that the company open-sourced in May. WebRTC is supported by Mozilla and Opera, and Google started to integrate the framework into its Chrome browser earlier this month. “Work has started to move Google Talk completely to WebRTC,” it says on the project’s web site.

At that point, users won’t need a plugin anymore to use Google Talk, and the same should eventually be true for Hangouts. Here’s what a Google spokesperson told me via email about the connection bewteen the Google+ video chat service and the framework: “A lot of the technology in Hangouts feeds into the WebRTC, and we contribute a lot of feedback to help shape the WebRTC interface. At this point though, our plug-in and the protocol are different efforts.” He refused to reveal any future plans, but trust me, the writing is on the wall…

Open codecs

Google Talk and Hangouts currently use technology Google is licensing from Vidyo to facilitate video chats. Video is transmitted in H.264/SVC, with H.264/AVC and H.263 being used as fallback solutions. However, there are strong signs Google will eventually switch to open codecs.

Google open-sourced its VP8 video codec last year as part of the new WebM video format, and real-time communications were one of the big issues that VP8’s programmers wanted to improve with the codec from the onset. In fact, VP8 is already being used by Skype for its group video calling feature, and Google’s WebM project manager John Luther wrote in February that VP8 is an “exceptionally good codec for real-time applications like videoconferencing.”

So when will Hangouts be switching from H.264 to WebM? Google+ Project Lead Bradley Horowitz indicated on This Week in Google on Wednesday that his team is already testing alternatives to the current codec. A Google spokesperson didn’t want to discuss any future plans for Hangouts when I asked about the codec issue, but here’s a clue: WebRTC is based on the VP8 codec, which means that H.264 could get displaced as the default codec for Hangouts as soon as the video chat service rolls out its native browser integration.

Device integration

This is where things get really interesting: Hangout’s cloud-based architecture and its upcoming browser integration will eventually make it possible to deliver an optimized group video chat experience to a whole range of devices. Desktop users will get to view full HD video, users on mobile devices will receive optimized streams to deal with bandwidth issues. And Google TV users could see Hangouts appear on their TV sets sooner than they think, because Google TV comes with a full-blown Chrome browser.

A few companies have started to bring multi-person video chat to mobile devices, but cross-device video conferencing is still in its infancy, and Google could have a good chance here to capture the market early on. Of course, the company didn’t want to comment on the specifics of bringing Hangouts to mobile devices, but what Google’s spokesperson told me wasn’t exactly a denial either:

“Again, we can’t comment on future product plans. However, Google Plus heavily invests in mobile products as we believe you should be able to share and communicate, whether you are on the web, tablet, or phone.”

26 Responses to “The technology behind Google+ Hangouts”

  1. Warmbowski

    To me, the key difference of this video conference service to the Skype service, is the Scalable Video Coding (SVC) that they licensed from Vidyo, which differs from traditional AVC encoding in that it allows layers of fidelity in the video stream, so that it can be adjusted on the fly to what the endpoint can handle bandwidth and CPU wise. Is this also possible with WebM?

  2. Google is the major key player before WebM project featuring VP8 open source video codec. Earlier this year, it had recently dropped support for H.264 video codec for its Google Chrome browser and switched to WebM video format. So, it means Hangouts supporting H.264/SVC video format may face problem in Chrome, the war machine of Google, itself. So, Google has to quickly switch to VP8 video format or have an on-the-fly conversion from H.264 to VP8.

    • pugscanfly

      Google has yet to drop support for H.264 in Chrome. I have a feeling that WebM is not robust enough to do what they need to with Hangouts at this point. WebM seems like a red herring to me. The whole notion that it is free and open is ridiculous. It’s as free and open as Android is.

  3. black_caeser

    > And Google TV users could see Hangouts appear on their TV sets sooner
    > than they think, because Google TV comes with a full-blown Chrome
    > browser.

    Mind that Opera is used as embedded browser for quite some TV sets like Sony Bravia. WebRTC would open Google+ Hangouts to those users too …

    Also this could be the breakthrough of WebM, forcing Microsoft and Apple to include it with their browsers.

  4. SumWon

    I love how you say that this uses “the cloud”, when in fact, it does no such thing. It’s a classic client-server model that’s been in use for quite some time, though perhaps not for real-time video.

    Step 1. Write article
    Step 2. *Insert buzzwords errywhere*
    Step 3. ???

    • Although I don’t think this is your “classic” client-server model, I do agree that it is probably not a full cloud implementation, as that won’t make sense in this instance, probably more a cluster type of environment.

      Problem is, there is no standard accepted definition of what the cloud is, that is why everyone uses the buzzword for any technology.

  5. Google+ is another GFail.

    Perhaps the technology being used by Google is part of the problem, and not just with “Hangouts”.

    Google led the way in search, but that was over ten years ago. Since then, they have lost their way, and years ago they become a company of immitation not innovation.

  6. If they can combine the video chat with circles, so that only some people can video chat with you at certain times it will be awesome.

    Funny thing though, a month ago everyone predicted how Facebook will destroy Google with Facebook search, now it seems the other way around if the hype about Google+ is anything to go by!

  7. Sounds too good to be true. I predict that the competition will become fierce in the social networking market from here on out. Justin Timberlake is bring sexy back with MySpace and his new movie. Facebook is slipping because of their partnership with Microsoft. Google is set to surpass Facebook as the leader in Social Networking because Google + is advanced. Netiquette is more important than ever.

  8. Google has really pushed at making its social features work, I really think they will pull it off. It might take a while as its still relatively new in the UK, but its slowly leaking through.

    I also had a look at the screen shots of Googles social network feature they launched on Tuesday and it looks so promising.

  9. XMPP Spec has Muji, multi-user jingle, which is a mix up of multi-user-chat and the jingle a/v transport. I’m still holding out hope Hangout leverages existing IM standards such as Muji.

    Maybe a Jingle-Nodes person can chime in and discuss whether there’s a way to make Muji P2P, which is what the WebRTC stuff is for.

  10. yuvamani

    Check out which has been doing h264 based group video conferencing for a while now and works with Skype too.

    However there is the scale that Google brings in.