Hardware Reference
In-Depth Information
Studying the number of changed pixels is one of the best ways to understand
the motion detection system. The number will spike whenever you move the
camera, but should come to rest at zero as Motion learns about light sources
and applies an automatic noise filter to minimize the risk of false positives.
Attention Google Chrome users
To find out how to embed this direct MJPEG stream into an HTML
page so that it can be viewed in Chrome, take a look at the upcoming
Building a security monitoring wall
section of this chapter.
5.
Now if you wave your hand in front of the camera, the pixel counter should
climb and a rectangle will be drawn onto those areas in the image where
Motion detected the largest changes in pixels.
If the number of pixels climbs over the threshold value (
1500
by default) set
in the configuration file, an event will fire, which is currently set to play the
high-pitched tone.
When no motion has been detected for the number of seconds specified by
the gap value (
60
by default, currently
2
), the event ends and a new event
can begin.
6.
Let's look at an alternative method to tweak the detection system called
setup mode. Open up a new tab in your browser and enter the address
http://[IP address]:7070
in the address bar.
What you're seeing here is a simple web admin interface to control Motion.
When we hook up more than one camera to Motion, each camera will have
its own thread and configuration, but right now there's only one thread and
one configuration labeled
All
. Click on
All
to proceed.
7.
The little menu system is not very advanced but does contain a few
convenient shortcuts:
detection
allows us to temporarily disable the motion
alarm, and
action
allows us to write JPG snapshots or quit Motion. The
conig
shortcut is perhaps the most useful one and allows us to try out
different configuration directives on the fly.
8.
Click on
conig
and then click on
list
to get a list of the currently loaded
configuration directives. Now click on
setup_mode
, select
on
from the
drop-down menu, and click on the
set
button.
