MACROMEDIA FLASH COMMUNICATION SERVER MX-SERVER-SIDE COMMUNICATION ACTIONSCRIPT DICTIONARY Dokumentacja Pobierz pdf (Strona 132)

Chapter 454

Managing bandwidth

You can control the amount of data the server sends to each client by providing an approximate

bandwidth capacity. There are a few ways to do so. One way is to configure the capacity for the

Flash Communication Server in the configuration file (Config.xml). For more information on

this technique, see Managing Flash Communication Server. Another way is to use

NetStream.receiveVideo to specify the frame rate per second of the incoming video (the

default value is the frame rate of the movie). A third way to match the data flow with capacity is

to use

Camera.setQuality on the client side and Client.setBandwidthLimit on the server

side to inform the server of the client’s capacity. This technique is illustrated in the following

sample.

The code in the doc_bandwidth.fla file allows the user to choose between different bandwidth

settings. On the client side, the microphone and camera settings are updated according to the

user’s selection. On the server side, the bandwidth limit is updated. You can find the sample file

for this code in the flashcom_help\help_collateral\doc_bandwidth directory under the installed

Macromedia Flash MX authoring directories.

To see this application in action, create a directory named doc_bandwidth in your flashcom

application directory, then open doc_bandwidth.swf. See “Creating your working environment”

on page 31 if you want to re-create the sample.

The client-side ActionScript provides the interface for the user to choose between three settings:

Modem, DSL, or LAN. There are three buttons on the stage, which when selected return 1 for a

modem setting, 2 for a DSL setting, or 3 for a LAN setting. When the user changes the

bandwidth limit choice, the camera and microphone settings are updated. Because this change is

barely noticeable, extra code in the

updateBandwidth function also changes the screen size based

on the settings chosen.

_root.Modem_btn.onPress = function() {

// Call updateBandwidth to change

// camera and mic settings and inform

// the server

_root.updateBandwidth(1);

}

_root.DSL_btn.onPress = function() {

_root.updateBandwidth(2);

}

_root.LAN_btn.onPress = function() {

_root.updateBandwidth(3);

}

On the first frame of the FLA file, you can find the following code, which initializes the camera

and microphone, plays the stream from the server, and updates the camera and microphone

settings based on the user’s choices.

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MACROMEDIA FLASH COMMUNICATION SERVER MX-SERVER-SIDE COMMUNICATION ACTIONSCRIPT DICTIONARY Dokumentacja Strona 132