User Guide

Camera.setQuality() 509

• 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.

Example

The following example writes to the log file when video activity starts or stops. Change the

motion sensitivity value of 30 to a higher or lower number to see how different values affect

motion detection.

// Assumes a Video object named "myVideoObject" is on the Stage

active_cam = Camera.get();

x = 0;

function motion(mode) {

trace(x + ": " + mode);

x++;

}

active_cam.onActivity = function(mode) {

motion(mode);

}

active_cam.setMotionLevel(30, 500);

myVideoObject.attachVideo(active_cam);