Technical information

by Forest Key and Chris Hock
28
What file formats does Flash Communication Server MX stream?
Flash Communication Server MX can stream both FLV and MP3 file
formats.
What standard is the Audio compression based on?
For playback, Flash Player supports MP3, ADPCM, and a proprietary voice
codec. For capture, Flash Communication Server MX supports the
proprietary voice codec. The voice codec can be licensed from a company
called Nellymoser.
How can I send the best video depending on the client connection?
Because Flash Communication Server-based applications establish a
persistent connection between the client and server, developers can
determine the client's connection speed and deliver the most appropriate
video. For example, for recorded video, the developer can choose to deliver
the video with the bit rate closest to the client’s connection rate. For live
video, the developer can choose to alter video stream properties such as
video size, frames per second, quality, or bandwidth settings to deliver
appropriate video.
How can I send Flash Video most effectively over my network?
Because only bits that are viewed are sent to the client, streaming in itself
offers a very effective form of video delivery in terms of network bandwidth.
In addition, Flash Communication Server MX also provides for server-to-
server stream passing (or splitting) to enable a branch and leaf style cluster
to be configured. This way, the same live or recorded video stream can be
served up from multiple servers running Flash Communication Server MX
on the network so no one machine becomes overburdened. This enables
developers to create scalable server configurations to handle large numbers
of clients and supports failover and redundancy servers. For more
information about how to set up Flash Communication Server MX to
support a multiple server environment go to
www.macromedia.com/desdev/mx/flashcom/articles/scalable.html
What kind of capacity backbone is needed for streaming video over the
Internet with the Flash Communication Server?
The capacity that you need to stream your video broadcast depends on the
number of people that will be simultaneously viewing your video and the
size of your video stream.
You can get a simple estimate of the bandwidth you will need to stream
your video by multiplying the number of simultaneous viewers that will be
watching your video times the bandwidth at which they will be viewing it.
For example, if your video is being streamed to 4 viewers and each video
broadcast is at 200 Kilobits per second (kbps) then the backbone you'll need
is 200 kbps x 4 = 800 kbps.
For more information download the white paper on this topic at
www.macromedia.com/software/flashcom/productinfo/editions/fcs_whitep
aper_bandwidth.pdf.