User Guide

Camera class 35
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).
■ To prevent the camera from detecting motion at all, pass a value of 100 for motionLevel;
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 level 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 level value when you’re not moving; when you are moving, activity values
frequently exceed your motion level 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.
NOTE
Video can be displayed regardless of the value of the motionLevel parameter. This
parameter only determines when and under what circumstances
Camera.onActivity is
invoked—not whether video is actually being captured or displayed.