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 compute....
Set up Your Own Webcam by: Silvina Georgieva 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 bandwidth for your camera to stream, the answer is yes.
If not, you'd better stick with the still image camera - that will make the
process 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 bandwidth 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
bandwidth 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 auto reload the picture after a given
period that you can define. (This does not apply to the server push method,
since it is continuously streaming a video feed). META Tag Command Although 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 bandwidth 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: 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 embedded 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 Online Camera 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.
