Set up Your Own Webcam

These days, web cameras are everywhere. Your friends have one, maybe your office
or the university that you study in also do. So, you decided to finally go with
the crowd and get a camera. Now that you have it at home and connected to your
computer, you probably wonder: "How do I make this thing show a picture
online?" We are here to explain.

Setting up your own web camera is easy: all you need is a computer, the cam
itself, webcam software which will do the broadcasting, and an Internet connection.

Streaming Video vs. Still Images

The first decision you have to make before putting your camera live is if it
will show streaming video or still images. If you have visited a webcam directory

such as OnlineCamera.com and looked
at a few cams, you have most probably noticed that some of them show a continious
stream of live video, while others refresh the page in your browser and show
a different picture at a pre-set time interval. The first flavor, the streaming
ones, are without doubt more attractive to a viewer, but can you support such
a camera? If you have a broadband Internet connection, and you can afford setting
aside much bandwith for your camera to stream, the answer is yes. If not, you'd
better stick with the still image camera - that will make the proccess lighter
for both you and your camera's viewers, and such a connection can work without
problems even if you access the 'net through a dial-up connection. Also, this
will give you the chance to show the world images with higher picture quality
- larger and without grains, - although those images won't be moving the way
they do on TV.

It is also important to consider the image size of the shots being taken by
your webcam: the greater the image, the lower the refresh rate. A 640x480 pixels
image can be great looking, but it can be great trouble for users with slow
Internet connections, especially if the refresh rate of your camera is set to
an interval such as 3 seconds. Take a look at the options of the broadcasting
software that came with your webcam, and think of how different options that
it offers would look on other people's computers. If you have friends and relatives
living away from you who have Internet access, you could ask them to test your
camera. Set it to different combinations of image size and refresh rates, and
ask them to look at it and tell you how it looks. This way you could have some
great fun with your camera even before you show it to the public. In case you
don't have people to experiment with, keep the following tips in mind: a reasonable
image size can be 320x240 pixels if refreshed every 20-30 seconds. If you want
the picture to update more often, try with an image size of 160x120 pixels.
Using that, you can have refresh rates of up to 10 seconds. If you stream live
video, try to keep an image size of 160x120 so slow Internet connections can
see your webcam without problems.

Methods of Delivering the Webcam Shots

Client Pull

This method is the most popular, designed to show single snapshots from the
webcam. It is the most easy method to set up, and the one that works perfectly
for dial-up Internet connections. It also won't take much bandwith from your
connection, so you'll still be able to surf the web, get e-mail, and other things
while your webcam snaps shots. However, you won't be able to serve live video
feeds with this method.

This method is usually accomplished with an FTP connection that sends the last
shot captured by the WebCam to the site hosting your web pages.

Server Push

This is the most resource-consuming method, and thus, the least implemented.
You should use it if you'd like to stream live video from your cam to viewers.
It has its limitations, some of which are:

• It requires a high bandwith connection.


• You must put a limit to the video stream for each user connecting to it.



• You can't use a dial-up connection for this method.


• If there is a firewall in your network, it can disallow you to use this
  method, or can limit you in some way or another.


• Only the most recent browser versions support server push.

To set up a server push webcam, you'll need a fixed IP (dynamic IP's are also
possible, but you need more resources) and server push software.

How to Refresh the Image

Once you've decided which kind of webcam you are setting up, you need to decide
how to make it refresh the image.

To get the latest shot captured by the camera, your viewers will have to reload
it (usually by pushing the F5 button on their keyboard), unless you add some
extra HTML, Javascript code or Java applets which will autoreload the picture
after a given period that you can define. (This does not apply to the server
push method, since it is continously streaming a video feed).

META Tag Command

Altough this is the oldest method of refreshing a webcam image on a web page,
it is in use in many places, and works perfectly. This way of refreshing is
done via a little HTML code.

There is an HTML tag than can make a page automatically reload after a period
of time (in seconds) is reached. The syntax for this tag is as follows:

At the interval in seconds, the browser will reload the current page, and do
it over and over again until the user closes it. The most significant disadvantage
of this method is that the whole page is reloaded, so a heavy graphics site
will be a pain to reload on slow connections and will result in high bandwith
usage.

If you decide to use this method of refreshing your image, keep in mind that
some old browsers don't allow an image to automatically refresh after some reloads.
To work around this bug, add the following code to your page's HEAD tag:

JavaScript Refresh

If you don't want to make your viewers wait for the whole HTML page to refresh,
you can use the JavaScript language to make just the image refresh. Note that
the visitor of your webcam page will have to enable JavaScript in order to see
the image changing (nowadays, 90% of the audience does have JavaScript enabled).

Java Applets

Java applets are small programs embeded inside a web page, which load the webcam
images freeing the browser form that job. There are hundreds of Java applets
for this purpose available online, such as OnlineCamera
Java Viewer. You can put them anywhere in your webcam page and they'll refresh
the image for you, without refreshing the whole page, just the image.

Stay with us to learn more in the coming parts of this tutorial.

© 2005, OnlineCamera.com, All rights reserved.

Silvina Georgieva is Managing Director of OnlineCamera.com.



Founded in 1996, OnlineCamera is the leading independent webcam directory on
the Internet.

It has more than 3000 web sites currently listed, and grows with more every
day.

Contact: http://www.onlinecamera.com/contact.htm