Greetings.  My name is Ed Crump, and I’m the chief scientist behind the BitGravity LiveBroadcast system.  I’d like to take a minute to share some thoughts, inside information, and tips about the system we’ve developed for you.  First, some background …

Real-time, Live, to the Desktop!

Over 10 years ago at Wayfarer, I was developing a real-time messaging system (ala Push Technology) with the dream of eventually bringing real-time, high quality, Live Internet broadcasts to millions of desktops around the world.  Flash had just come on the scene (and was quickly snatched up by Macromedia to replace Shockwave).  A/V capture cards were a curiosity.  Dial-up users were the norm.  Pentium 100MHz systems were hawt.  Yahoo had a whole building of servers pushing a whopping 100Mbps.  Sadly, none of the pieces I needed were really ready.  The dream would have to wait.

I was able to realize the dream at DEMO 2008 when we announced affordable Standard Definition Live Broadcast for the masses.  And today, we’ve taken it to the next level at DEMO 2009 with our announcement of affordable HD Live Broadcast for the masses!

Here’s some insight to what happens behinds the scenes to deliver BGLive …

Pushing HD 1080p Live broadcasts to the masses

BitGravity LiveBroadcast is an end-to-end, global Live broadcasting solution that brings affordable HD 1080p broadcasting to the masses.  BGLive is built on top of BitGravity’s global next generation backbone which provides BGLive its scalability, efficiency, and cost-effective delivery.

Broadcasting HD Live is a challenge …

• capturing an HD feed in real time requires special hardware
• compressing (transcoding) an HD feed, in real time, so it can be broadcast over the Internet takes lots of number crunching
• delivering HD feeds to hundreds of thousands of users requires a global, next generation network
• watching heavily compressed HD broadcasts requires high end desktop machines or hardware decoding

NOTE:  Because of the volume of data that makes up an HD video stream capturing and transcoding are usually combined into a single step.

The main challenge with capturing HD video is matching the inputs:  connectors (Component, HDMI, HD-SDI, etc.), video frame rates, colorspaces, etc.  The video broadcast and production industries are fond of standards (which is why there are so many).  Fortunately affordable HD capture cards are becoming mainstream (e.g. the BlackMagic HD DeckLink Extreme), and they can insulate you from a lot of this pain.

Compressing (transcoding) an HD feed in real time is a much thornier problem.  The issue is you are trying to push ~12Gbps (1920 x 1080 x 24 x 30 * 8) bits into a 2Mbps stream that the end user can actually download and watch in real time.  There are hardware solutions for transcoding HD in real-time, but these all have issues, the predominant ones being that they are very expensive.  This can be a major roadblock.  We recognized this early on and decided to invest in building an affordable software encoding solution that runs on off-the-shelf hardware (Mac).

Delivering HD feeds to large audiences of Internet viewers is the real showstopper for most.  There is virtually no way to scale this by yourself without inventing your own Internet backbone first (i.e. to make a small fortune, you must first spend a large one).  Basically, you need to use a CDN or a compute cloud like Amazon EC2.  Either way, this is a distraction from your core business/service.

BGLive pulls all of this together and gives you an affordable, end-to-end solution for HD broadcasts.

1080p just doesn’t look good in anything less than 1.5Mbps

Most CDN’s that offer Live broadcast services have problems reliably delivering streams over 1.5Mbps.  The most notable reason is that their infrastructure was designed for the Internet that used to be, not the Internet of today.  The higher the bitrate, the fewer the concurrent streams that can be handled by individual servers and routers.

It’s very popular at the moment to use Amazon EC2 machines with Flash Media servers to try to scale Live broadcasting to the masses.  Unfortunately, Amazon throttles bandwidth to their EC2 machines down to 160Mbps (to prevent harm to their network) which in turn forces you to rent more machines to serve more streams.

BitGravity on the other hand developed a next generation network to support its CDN, and BGLive got to take advantage of it.  BitGravity’s network allows my Live servers to sport 10Gbps interfaces and deliver 6000 HD 1080p streams @ 1.5Mbps each whereas a 160Mbps connected EC2 machine maximum of 100.

Bottom line, our costs for delivering HD 1080p throughout the world are lower which directly translates to lower costs for our customers.

Don’t compromise quality

Live Internet broadcasting services traditionally trade off video quality (low bitrates and video frames) to reduce costs and reach a wider audience.  It makes for a poor viewing experience though.  This used to be an important feature when everyone was on dial-up modems, but the Internet has changed.

BitGravity provides for lower bitrate streams that are encoded at the same time as the high bitrate streams, and dynamically switches between them in our Flash player.  The net difference to the end user is the lower bitrate streams from BitGravity are much higher quality.  This is because BitGravity streams have the full frame rate and were generated using the original feed (not the transcoded copy).

Let’s face it, you don’t want to be dropping frames or pixelating your HD broadcast.  1080p deserves better!

Real-time isn’t exactly

We use the phrase real-time encoding, but this is misleading.  Real-time encoding means that the video stream can be encoded in real time:  it takes 1 second to transcode 1 second of video.  The piece everyone leaves out is how long the system takes to get to this state (like a CPU pipeline).  Some systems take minutes to achieve this state.  This means you are watching a live broadcast from minutes ago.  This is referred to as the delay from live.

Obviously the viewer’s sensitivity to the delay from live is a function of the stream content.  In particular, when you combine real-time chat with Live video where the folks in the video can react to the chat, it makes a big difference.

BitGravity delivers HD video to viewers around the globe within 4-6 seconds after it hits the camera, and our goal is to get that down to 2 seconds.  Obviously we are good net citizens and will obey all laws related to the speed of light!

(obscure reference:  “More Live Than Live!  That’s our motto!”)