Macromedia flash media server 2-developing media applications User Manual

Working with video

59

Consider the following example: a user wants to play a stream and has Flash Player 8 installed 
on their computer. Flash Player 8 is capable of playing On2 video. Flash Media Server 
requests the HappyStream.flv file. After contacting the server, Flash Player 8 determines the 
value of the server-side 

Client.virtualKey

 property. The 

virtualKey

 property maps to the 

On2 streams directory, instead of to the default streams directory and the HappyStream.flv 
stream encoded with the On2 codec is played. 

To create an automatic stream delivery mechanism based on Flash Player version, edit the 
vhost.xml file as follows:

<VirtualKeys>

<Key from="WIN 7,0,19,0" to="WIN 9,0,0,0">A</Key>
<Key from="WIN 6,0,0,0" to="WIN 7,0,18,0">B</Key>
<Key from="MAC 6,0,0,0" to="MAC 7,0,55,0">B</Key>

</VirtualKeys>

<VirtualDirectory>

<Streams key="A">foo;c:\streams\on2</Streams>
<Streams key="B">foo;c:\streams\sorenson</Streams>
<Streams key="">foo;c:\streams</Streams>

</VirtualDirectory>

For more information about editing the 

Key

 and 

Streams

 tags, see “Vhost.xml file” in 

Managing Flash Media Server. 

Delivering video based on bandwidth

To deliver video to a client based on the client’s bandwidth, encode the video at different bit 
rates (and optionally using different codecs) and create directories in which to store the 
streams, as in the following example:

■

c:\streams\Sorenson22k\mystream.flv

■

c:\streams\Sorenson150k\mystream.flv

■

c:\streams\Sorenson300k\mystream.flv

■

c:\streams\Vp622k\mystream.flv

■

c:\streams\Vp6150k\mystream.flv

■

c:\streams\Vp6300k\mystream.flv