Q
What is a ULS?
A
ULS is short for User Location Service. Before ULS, people wanting to call someone over the
Internet had to type in the other person's IP address which are long numbers like this:
207.215.121.99. The ULS was developed so you don't have to deal IP addresses any more.
Instead, you can type in the person's name or e-mail address, and the ULS will find and enter
the proper IP address for you. it's like an on-line telephone operator who will dial the proper
numbers to hook up with others over the Internet. ULS is actually a specifically designed web
server that maintains the list of users currently available on the Internet. When someone starts
the Internet Video Phone program, it connects to the ULS and uploads the information about
that person (name, e-mail address, and so on). Also, ULS server registers IP addresses of every
user connected. This way, when you want to call somebody by specifying the person's e-mail
address, the ULS takes care of providing your computer system with the correct destination IP
number.
Q
What is image compression?
A
A formula and process for eliminating unnecessary or redundant data in images to make the
size of a compressed file as small as possible without sacrificing quality. Compressed video (or
audio) files require less storage space, play back faster, and demand less of the computer's CPU
for processing. There is currently a standard video compression technique (called the H.263
standard) for video email and video conferencing.
Q
OK, so which image compression algorithm do I choose?
A
Compression is a tradeoff between life-like motion and image quality. More compression
means more frames can be transmitted per second, but at lower image quality. So the basic
question becomes: "Do you want a clearer image or more 'life-like' motion?" You have to
choose which is the most appropriate combination of compression and image quality for your
particular video conference. The easiest way to find the answer for you is to try out several
different compression algorithms to see which one fits best. By the way, there are a lot of other
things you can do to make the motion more life-like besides image compression. Reducing the
window size on the screen is one of the easiest ways to see more realistic motion because less
data has to be transmitted for a smaller window.
Q
Can I use OpArt Video Mail without sound card?
A
Yes. You still can use OpArt Video Mail to capture video only video mail.
Q
Can I send the video e-mail to any person with any system?
A
You can send video e-mail to the person with Win95, Win98 or WinNT, but not for Win3.1.
Q
What’s kind of software needed to playback the video email?
A
You don’t need any extra software. You just need to install multimedia tools when you install
operating system.
Q
Can I get real time video and audio video email ?
A
Yes. The video email you captured is real time. The audio and video quality is very smooth.
Q
What’s the frame size for the video email ?
A
It is QCIF (176*144).
Q
What’s the compression ratio for video email?
A
The answer could be 20 ~200 for video. It depends on the motion of the video. And it is 2 time
compression for audio.
