TechNote (Archived)

Camera, Microphone, other classes retain properties after first SWF loaded

Issue

After loading a Flash Player movie (SWF)”which sets certain properties, such as mic.rate”subsequent SWF loads attempting to reset the same properties fail. The initial value set by the loaded SWF remains the default value for the duration of the parent movie.

For example, in ActionScript 2 (AS2), if an SWF was loaded that attempted to set mic.rate to 8khz, the Flash Player allow/deny settings for audio would appear. If the end user approved the audio change, then mic.rate would be 8hz until another SWF loaded and attempted to change the rate to some other setting. At that point, the allow/deny settings would appear again and the end user could accept the change.

In Flash Player 9/ActionScript 3 (AS3), the behavior changes. If the first SWF loaded attempts to change the default property of certain objects such as mic.rate, the allow/deny settings for audio will appear. However, that setting will remain for the duration of the parent movie. Attempting to load another SWF file that resets the mic.rate will not throw the allow/deny dialog box and will fail to change the property.

This may affect, but may not be limited to:

Camera
Microphone.rate
NetConnection.defaultObjectEncoding
XML.defaultSettings

Reason

This behavior is changed by design in Flash Player 9.

Ref. (171182)

Solution

Because of this change, it may be necessary to guarantee that any SWF that affects mic, camera or other affected properties loads first to guarantee correct settings for the duration of the parent movie.