Video Call Software

Video Call Software If you decide to use a computer, the software you decide to use will be based on the video call functions you want to perform. For example, if you are an AOL user on Windows and are familiar with AOL's Instant Messenger, you'll need to know that AIM interacts with Apple's iChat AV solution for a video call. SightSpeed, one of the better video call solutions, also has Windows and Mac capability.Yahoo's Instant Messenger was one of the ?rst to have video and audio capabilities. If you use Microsoft's MSN Messenger, it too handles audio and video, but only for Windows. By the way, all these solutions are free—a way for vendors to encourage use of their Internet portals or additional services. (More detail on software video call solutions is included in Chapters 6–8.) Frame Rate and Picture Quality One of the things to keep in mind when you're using video call solutions is the kind of frame rate and picture quality you get with the solution.The best-quality video, the kind you see on television or your camcorder, is 30 frames per second (fps). Some solutions trade picture quality for improved frame rate so that the video is moving at real time, or 30fps, even though the quality is more "grainy." Most solutions slow the frame rate to 15fps in order to keep the picture quality high. 16 Chapter 2 ? Getting Started Let's take a look at a basic frame rate versus video quality and how they affect band- width.This is only an example, and not a realistic one, of the data being transferred as solu- tions use compression to reduce the amount of data sent.The typical video call screen size is 320 × 240 pixels, for a total of 76,800 pixels.At 30fps, that is 2,304,000 pixels being sent every second. If you cut the frame rate in half, to 15fps, then only 1,152,000 pixels are being sent every second.You can see the obvious savings you'll get by reducing frame rate to reduce the amount of video data being sent. This is important for home users because the speed at which you send data, called the upload speed, is always less than the speed at which you receive data, called the download speed. Software makers have to balance frame rate and image quality to handle the limita- tions of current broadband connections. But have no doubt that the quality of video calls you can do today is very good and designed speci?cally for home broadband connections. Vendors use compression and fancy formulas to adjust the quality of the image and balance it with the frame rate to keep the video ?owing and the audio quality good.This is also why you will see the video screen size in a 3 × 2-inch screen, to reduce the data that is being sent. When these solutions expand to large windows, the data does not increase, only the image size does, so the video gets grainy, just as though you blew up a 4 × 6-inch pho- tograph to 8 by 11 inches. So, the more frames per second that are sent, the higher the quality of the video image and size of the video window, the faster your bandwidth or Internet connection needs to be. Since bandwidth to the home has a limit, some video call solutions limit the size, quality, and frames per second to reduce the bandwidth required.Therefore, you have to decide what is more important to you, frames per second or picture quality. Many applications do not allow you to adjust the picture size, and ones that do are just blowing up the picture, not actually increasing the amount of data being sent, resulting in a grainier picture as it increases in size. I prefer quality over frame rate because I want to see the best picture possible rather than a grainy person moving in real time. When performing video calls with my children, for example, it is the ?ne details that I want to see, like a missing tooth, so quality is more important than smooth movement, in my opinion. Some of the solutions have automatic bandwidth meters and adjust both quality and frames per second based on the high-speed connection. MSN Messenger, for example, keeps a very good picture and reduces the frame rate based on the slowest of the two connections in the video call. Latency, the delay between the time you say something and the time the other party hears and sees you, is also a concern. Remember many years ago, when making long dis- tance calls, you had to learn to wait a few seconds before saying something so you would not "step on" the other caller? Latency is not a desirable condition and is often found in server-based solutions that relay the video call.

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