How web broadcasting works
Webcams are those handy little cameras that
attach to your PC and send images to a web page that can be viewed by others.
This enables you to share daily life events with friends and family in other
parts of the country or the world, or to arrange a video-conference with
colleagues and maintain long distance relationships of all kinds. Of course the
number of ways to use this technology is limited only by your
imagination.
Web Cameras
But before you buy a webcam, it pays to
understand a little about how the technology of broadcasting images over the
Internet works. Of course, if you're a full bottle on this already, you can skip
this section and go straight to browsing the options on Myshopping.com.au where
you can compare products and suppliers, their specifications and
prices.
Webcams provide 'real time' images of people; places and events
that can be viewed 'live' on a web page. The broadcasting end has a camera that
captures the images, feeds them into a computer to an ISP and out to viewing
pages across the Internet. There are two different types of broadcast: streaming
images, where the images are a constant stream downloaded in video format; or
Java, where the images are captured at fixed time intervals and refreshed on the
web pages at a rate fixed by the broadcaster.
The Applications - What are
you intending to broadcast, and to whom?
There is a wide range of uses of
webcam technology. Some examples include personal 'Big Brother' style diaries,
sharing of family events, workplace security, video conferencing, virtual
tourism, road traffic management, weather watching, event broadcast and a host
of others.
Before you make a choice about any webcam equipment, it helps
to decide exactly how you want to use the technology, in other words, what you
are intending to broadcast. This decision will impact upon the type of camera
you use, and how you use it.
A second consideration is, who will be
viewing your content? What level of quality is expected? This will help
determine the type of camera you use, the software involved and your Internet
connection. Of course, your Internet connection may be a limitation on how much
you can do.
The requirements for video conferencing are different from
the requirements of workplace security, which are different again from the
requirements of sharing a family event.
The physical
components
There are a number of physical components required to make web
cam technology work. At the top of the list is the camera itself. Then,
depending on the type of camera you use and the way in which you want to deliver
the content to the Internet, you may need to incorporate video capture hardware
in your computer. Some software is required to help you process the data, and
Internet connection is required and a web page into which the data is
fed.
CAMERA CHOICES
Your choice of camera depends somewhat on what
you are intending to show. If you need to reach a large public audience yo may
want good quality camcorder or megapixel camera that captures high quality
images. If it's just for seeing who's at your front door or keeping an eye on
the kids in their playroom, then it may not need to present high quality images.
If you are intending to use it outdoors, it will need to be weather proof and
you may need to consider sun and UV protection. Available power supply and any
robotic requirements for camera movement and focus are extra considerations.
Dedicated webcams
The most basic webcams connect to a PC using a simple USB connection. A wide
range of cameras with accompanying software at a range of prices is available
for this type of application. Simply search though Myshopping.com.au to compare
prices and specifications. Dedicated webcams are simple to install and easy to
use, but come with limitations that affect the quality of the images, such as
low number of frames per second (refresh rates) and resolution (pixels per
inch).
Camcorders and security cameras
Higher quality images and more camera control come from using camcorder and
security cameras. To use these devices you will need to add a video capture card
to your PC. Once you have that installed however, you can use a wide range of
cameras from broadcast cameras to miniature spy cameras. You can include
variable lens options, filters for daylight and low light situations, as well as
robotic controls for panning and focus adjustments. You can search through
Myshopping.com.au for camcorder selections.
Integrated cameras
An integrated camera combines the camera and the optical hardware with a video
server, and as such requires no additional software. They can be used in network
situations or as stand-alone devices for monitoring progress on a construction
project for example.
Megapixel cameras
Network megapixel cameras combine network capability with high quality digital
camera technology. These cameras offer excellent quality but this creates large
files sizes, therefore they have limited application in constant streaming
video. However for interval refreshed archive image collection, they are ideal,
providing a constant record and high quality. You can search through
Myshopping.com.au for digital camera selections.
SOFTWARE
If you are not using an integrated camera solution, you will need to install an
encoding program like Webcaster or MediaCaster to transfer your images to a web
page.
At the receiver end, when web surfers browse the internet and wish to view live
video on the web for the first time, they will need to download dedicated
applications that show the content such as an ActiveX control, Windows Media
player, Flash player or the like.
INTERNET CONNECTION
Finally, you need an Internet connection. The hardware you will need may include
a modem for dial-up connection, or modem/router for a broadband solution.
Naturally the higher the quality you want, or the faster refresh rate you want,
the more bandwidth you will need. ADSL (Broadband) is going to offer you the
best solution, but keep in mind what your Internet connection when you are
making choices of cameras and feeder software.
Webcam applications work well with wireless solutions. Make sure when you are
purchasing a camera or network video solution that it is compatible with any
wireless system you may be using in a LAN.
Key considerations
The specifications that are variable with webcam applications,
and are affected by camera type, web interface and Internet connection, include
the number of frames per second and the image resolution.
Frames-per-second is the number of times a still image flashes by in a second to
give the appearance of moving pictures. In Australia, the standard television
PAL format is at 25 frames per second. A webcam with up to 30 frames per second
will show normal video images. But the more frames per second you demand, the
more bandwidth, memory and processing power is required.
Resolution is measured the number of pixels per inch. High quality photographs
require a high resolution. But the standard for web images is a low 72 dpi.
Higher resolution images will not be of any better visual quality, just slower
to upload and download.
Use Myshopping.com.au to compare different webcams, camcorders and digital
cameras. You can compare the prices and specifications of the different products
and brands, and a wide range of reputable vendors.
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