How I introduced in my previous post , Rai Net the internet company of RAI, the Italian public broadcaster, during the last FIFA Confederations Cup South Africa 2009 delivered free, live Web broadcasting in high definition television quality (720p) of the Italian soccer team matches during the tournament using Live Smooth Streaming .
Smooth Streaming is an innovative technology based on IIS Media Services and Silverlight, which the scope to simplify and make a reality delivering video content at high quality level through Internet up to true HD for Live and VOD.
Smooth Streaming permit to solve one of the most significant limits in Internet video streaming connected to typical behaviors of the last mile for reproducing High Quality videos with high bitrates. When we think to the way that the content is delivered to the client, we have a lot of parameter that change every second during the client reproduction. In particular bandwidth and CPU power availability conditions change every second and causing a video glitch and buffering during the reproduction of the content, especially for the content at high level of bitrates, generating a poor user experience.
During the reproduction of the content Smooth Streaming dynamically detects current network and local PC conditions, and seamlessly switches the video quality of a media file that a Silverlight player receives. Consumers with high-bandwidth connections and newer hardware can experience HD quality streaming, and others with lower bandwidth speeds or older hardware receive an appropriate stream for their conditions, allowing the audience to enjoy an uninterrupted streaming experience with the highest quality possible.
In my previous post for Confederation Cup and for Smooth Streaming and in general and in the official web site , you can found more information about this innovative technology
After the success of this first test for Live Smooth Streaming, Rai Net have expanded the use of this technology for sports event on Rai Sport portal and delivered, up to true HD for Live and VOD after the Live event: Roma 09 FINA Swimming world championships and Berlin 2009 Athletics World Championships.
In the follow pictures you can see some screen shots from Rai Sport Web Site from Roma 09 FINA Swimming world championships were you can see the adaptive part of smooth streaming at work:
An from Berlin 2009 Athletics World Championships:
The architecture used for these events is practically the same used for the Confederation Cup and illustrated in the previous post, with the exception of the CDN because for this event RAI use two different CDN and balance the load on both at 50%. In the follow picture you can see the architecture used for these two events:
The original HDTV 1080i signal in input is encoded in 7 different bitrates streams composed by a contiguous 2 secs video chunks codified in VC-1, created by 2 encoders. Each encoder creates 3-4 streams and synch through the encoders are achieved with a timecode generator in input in the encoders with the source video. Encoders push the streams to an origin server farm in load balancing were the two CDN pull for distribute Live, archive streaming and XAP code and offers these to Silverlight client player published on RAI.IT and RAI.TV portal .