Under the Hood: Going for Gold
Sadly this is the last Olympics that CBC will be covering for a while. That said, this is also the most well covered Olympics in CBC history. Partly thanks to the Internet and cbc.ca.
Don’t Feed The Animals
cbc.ca/olympics provides you with up to 12 online “channels” where you can watch Olympic events live. This is possible thanks to the folks in Television (specifically Web Presentation group), encoding software by Digital Rapids called StreamZ, and Akamai.
The Olympic feeds are back hauled by Television to Toronto where they are encoded by the Digital Rapids boxes. They are encoded in Windows Media v8 at 500kbps. This stream is then sent to Akamai for distribution.
In most cases the video you see are raw feeds from the venues. This means that there is no commentary. The only audio you here is ambient sounds from the event.
A lot of people like these feeds as they provide coverage for their sport even if it is not available on television.
Canada Only, Please
Due to licensing restrictions by the IOC, only Canadians are able to view Olympic coverage provided by the CBC. As such, we’ve had to use technology from Akamai to ensure that we follow the rules.
The Akamai method of “geofencing” (as we call it) is more sophisticated than what I described earlier. Multiple methods are used, some of them are:
- Your IP Address. Using a database of known IP blocks and locations.
- Which Akamai DNS server you use. When you look up a host name (like www.cbc.ca) you hit a specific Akamai DNS server. Akamai knows which DNS server is in which country and uses that information to figure out what country you’re in.
BGP Metrics. In a nutshell, Akamai looks at what other servers/routers you go through to get to the stream. If those are in the country Akamai thinks you’re in, then the confidence level goes up. - Timezones. Using a piece of javascript on the client side. We figure out what timezone your clock is set to. If it matches with one of the timezones in the country Akamai thinks you’re in, confidence level goes up.
- We have people who watch you.
The methods listed above, plus a bunch of others combine to give a Country accuracy level of 99%.
Trends
Because of the twelve hour difference (in the Eastern Time Zone) quite a few of the events happen late at night and early the next morning.
The above graph shows the number of people watching the streams over the past seven days. The majority of the watching happens between 8pm and 12am EDT, and 6am and 12pm EDT.
Some days are more popular than others (like August 14, versus August 16). The little red arrow you see on August 19, at around 12pm EDT is when the most users were watching the streams ever.
I suspect that the closing ceremonies will generate the most streaming traffic during the Olympics.
|
Email This Post |
| CBC.ca web site, Specials, Under the Hood |
You couldn’t have chosen a format better than Windows Media? People on Macs have to use a special plugin, and even then the video is so choppy that it’s unwatchable.
Fantastic Job CBC!!!
CTV has their work cutout for them in 2010.
Another example of servers for the Olympics videos is shown at the Seattle Post-Intelligencer
Linkname: Why the Olympics didn’t kill the Internet
URL: http://blog.seattlepi.nwsource.com/buzz/archives/146456.asp
linking to http://blogs.zdnet.com/perlow/?p=9221
which explains Limelight Corp.’s agreements.
“Where Limelight differs from Akamai and why the Internet didn’t “melt” is quite simple — they are completely “off the cloud”. In other words, unlike Akamai and similar content caching providers, their system isn’t deployed over the public Internet”…….
Bill Lee:
As you can see, the internet didn’t “melt” anyways, even if you are watching Akamai feeds.
Did you read Akamai’s response to that article?
http://blogs.zdnet.com/perlow/?p=9224
The feeds worked quite well form my mac, I used the VLC media player and plugin and I was able to watch them fine on my mac. I find using flip4mac ends up screwing up the aspect ratio etc.
Another, and in my opinion better way of watching the stream is to take the direct stream address (easy to extract with an addon like adblock plus) and watch it within VLC, you then have a fully scalable window and you can have more than one stream at a time
I would of liked a more technical description of the streaming system on this post, like how the akamai reflector port works with java
Paf,
I’m not quite sure I understand your question.
The akamai reflector port is just the public streaming url. There is no Java involved at all.
[...] Beijing Olympics: CBC Live Webcast Magic Interesting piece about some technologies used by CBC in its Live Olympics Webcast Magic. [...]
I just loaded up the new Firefox browser on my computer and popped in
a nifty little add-on that shows a country flag to let you know the location of the website server. Well guess what? The entire CBC site is hosted in the United States of America. What gives guys? The voice of Canada couldn’t find a Canadian server to host their own site????
Okay, what’s the name of that plug-in?
Hi Roxanne,
Where are you located? $10 says you’re located in the USA.
The CBC website is located in Toronto, Canada. We use a piece of technology called Akamai that automatically mirrors our website on servers all over the world.
We do this so that you dont have to go all the way to Canada to get our content. If you are located in the USA, then you will contact a server in the USA for our content. It’s faster this way!
Actually, the website is delivered via a content delivery network – a bunch of computers worldwide that cache pages from the origin (in Toronto) and forward them on to users. So if you’re in Canada, you get it from a cache server on your Canadian ISP or a hop or two away, if you’re in France it’s coming from a French one, and so on. Said add-on is effectively useless for sites delivered over a CDN – either its defaults aren’t very intelligent, or your ISP is most directly hooked up to the US.
Great piece on how all of this works! However, it seems to be working too well… viewing of the RDI live video stream is still turned off to the US. The message references the Canada-only requirement for the Olympics, but the games are over.