Computer Connection Primer

by Terry Williams
Published on Jun 25, 2001 12:00 AM



It seems like these days everyone wants to use their computer to edit and spice up their home videos. Trouble is, most people aren’t really sure how to go about accomplishing this task. This article is only intended to be a VERY basic overview. Subsequent articles in this column will go into more detail. In the meantime, if you have more specific questions or don’t understand something I cover, feel free to post a message, or e-mail me.

There is much confusion about exactly what is needed and how to proceed once all the connections are made. It doesn’t help, either, that the marketplace is flooded with dozens of different types of hardware, software, and various combinations of the two. To get to the bottom of all of the uncertainty, it helps to understand the basic concepts behind the process.

To start with it is very important to keep in mind that video information can be either ANALOG or DIGITAL. Older equipment captures, stores, and plays back an analog signal. Equipment of this type includes regular television sets, VHS videocassette recorders, and VHS/SVHS and 8/Hi8mm camcorders. Despite the fact that camcorders use a digital device (a CCD chip) to capture the image and many types of video equipment process the signal digitally as it is being captured, the final product is stored on tape in an analog form. Many types of newer equipment keep the signal digital all the way through the process, ultimately storing it in digital form on tape or some other type of storage media. Examples of this include miniDV, DVCAM, Digital 8, and digital still cameras. Likewise, the audio must end up in analog form. Even material that is digital from recording through playback still has to be heard via analog speakers.

In fact, there are many instances along the way where the signal is converted from analog to digital, or vice versa. This is one of the main sources of confusion. In all areas of audio and video production you have to keep a finger on the signal path. You need to know where the signal is going, how it is getting there, and what will happen to it along the way. Doing this will eliminate much of the confusion. Knowing and understanding the signal path will help you understand the entire process much better.

You must also keep in mind that when you go to load the video in to the computer, the computer will need the information in digital form. Consequently, if you have an analog camcorder (VHS/8mm) you will need to route the signal through an analog-to-digital converter. In this realm, that device would be a video capture card. If your camcorder is digital (miniDV/D8), then you won’t have to convert the signal, but you will still need a method to transfer that image from one device to the other. The most popular choice for this is FIREWIRE. Officially this is known as the IEEE 1394 interface. Sony’s version is called “i.LINK”. I will go into more detail in subsequent articles, but for now all you need to know is that Firewire is the method of choice for high-speed transfer of digital video information.

The process of controlling the camcorder during the transfer process is also an important concern, as is what form the information will take once it is digitized. Almost all digital video is compressed to save space and the process used to COmpress and DECompress the information is called the CODEC. Both of these processes are usually controlled by the software used for editing. Again, I won’t go in to detail, but suffice it to say that deciding what software to use is integral to knowing what the other pieces of the puzzle will be.

This is all very, very basic and is not designed to cover the topic in any great depth. In a new section that will start very soon, we will go in to greater detail and more fully explain each step of the process.