User Guide

196 Chapter 2: ActionScript Language Reference
Camera.setMotionLevel()
Availability
Flash Player 6.
Usage
active_cam.setMotionLevel(sensitivity:Number [, timeout:Number]) : Void
Parameters
sensitivity
A numeric value that specifies the amount of motion required to invoke
Camera.onActivity(true). Acceptable values range from 0 to 100. The default value is 50.
timeout An optional numeric parameter that specifies how many milliseconds must elapse
without activity before Flash considers activity to have stopped and invokes the
Camera.onActivity(false) event handler. The default value is 2000 (2 seconds).
Returns
Nothing.
Description
Method; specifies how much motion is required to invoke Camera.onActivity(true).
Optionally sets the number of milliseconds that must elapse without activity before Flash
considers motion to have stopped and invokes
Camera.onActivity(false).
Note: Video can be displayed regardless of the value of the sensitivity parameter. This parameter
determines only when and under what circumstances Camera.onActivity is invoked—not whether
video is actually being captured or displayed.
• To prevent the camera from detecting motion at all, pass a value of 100 for sensitivity;
Camera.onActivity is never invoked. (You would probably use this value only for testing
purposes—for example, to temporarily disable any actions set to occur when
Camera.onActivity is invoked.)
• To determine the amount of motion the camera is currently detecting, use the
Camera.activityLevel property.
Motion sensitivity values correspond directly to activity values. Complete lack of motion is an
activity value of 0. Constant motion is an activity value of 100. Your activity value is less than
your motion sensitivity value when you’re not moving; when you are moving, activity values
frequently exceed your motion sensitivity value.
This method is similar in purpose to
Microphone.setSilenceLevel(); both methods are used
to specify when the
onActivity event handler should be invoked. However, these methods have
a significantly different impact on publishing streams:
• Microphone.setSilenceLevel() is designed to optimize bandwidth. When an audio stream
is considered silent, no audio data is sent. Instead, a single message is sent, indicating that
silence has started.
• Camera.setMotionLevel() is designed to detect motion and does not affect bandwidth
usage. Even if a video stream does not detect motion, video is still sent.