Streaming Live Video
Ever so often CBC.ca streams live video for special events. In most cases this is a feed from CBC Newsworld but can really be from any CBC network or channel.
Our turn around time is approximately 5 minutes from the time we get the word to when the stream is live on the Internet. How is this possible? Read below to find out.
Getting The Video
All of the video that goes to air is funneled through Television Master Control in Toronto. This is great for us since all of the CBC.ca infrastructure is located in Toronto.
The video is provided by us from a group called Broadcast Engineering. We have a Leitch Video Router that allows us to direct multiple video inputs to up to 4 outputs. Attached to these four outputs are video encoders running windows media encoder.
We also have the ability to use “pre-integration” video. That is video that does not have any commercials. This video is used for on-demand content like the “News at Six” videos.
Distributing The Video
The video is encoded using Windows Media Encoder and delivered to our Windows Media Server. All of the video encoders at CBC.ca use the Osprey line of video capture cards from Viewcast. They provide a lot of advanced features not found in consumer grade video capture cards. These features include closed captioning support, in-hardware video overlays, and duplex access to the hardware (which allows you to have more than one program access the video capture device).
From there our CDN picks up the video for distribution on the Internet.
Once the stream is working various users at CBC.ca are informed and links to the video are placed on the website.
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Closed-captioning support? How? Are you aware how many details are involved in such “support”?
My old project to reuse Line 21 captions on RealVideo clips on the Web site was shut down without anyone telling me. We had a good thing going there without excessive complexity.
Interesting to hear CBC.ca is streaming some live video for special events. I hope CBC will do more. I personally quite like the Washington Post live event feeds. I think they use the AP feed sometimes. Of course, with WP, I am restricted to what WP cares about which mostly are US centric stuff.
Kempton
Joe,
Yes the card supports decoding line 21 and doing whatever you want with the text (mainly displaying it on screen in a seperate window, or saving to a file).
The lack of support comes into play with the format we use (windows media). I have yet to find a way to make the closed captioning available as part of the stream to users.
On a somewhat related note. Have you ever used or have any opinions on this product? (http://www.textgrabber.com/). Hmm.. last I checked it was selling for $199. Now $299.