Copyright Michael Karbo, Denmark, Europe.
Chapter 18. Digital video
Back in the beginning of 1997 I took part in a series of television programs called ”About personal computers”. The recordings were made in relatively primitive conditions by one of the smaller television stations, which really didn’t have access to any of the more advanced equipment.
I remember clearly the pride of the station: A room full of equipment for digital video editing. They had all of 400 GB hard disk for the storage of the video recordings, which were in the process of being edited.
Today a clever amateur can almost produce recordings of the same quality as the television station could in 1997. It requires, of course, equipment of good quality but technological development has brought prices down a great deal. Modern computers have fast processors and lots of RAM. Large hard disks cost a fraction of what they did earlier. Which means that a good computer is, in fact, well qualified for video-editing – and with an acceptable level of quality.
But you can easily work with video less ambitiously and without problems and this is what I am going to show you in this section of the booklet. You are going to hear about video in a number of variations using different sorts of hardware.
I will start by explaining how digital video is ”screwed together” purely in the terms of data. Then I will look deeper into the types of components – hardware and software – which are a part of this work. On the way, I will look at some practical examples from my own experiences.
I have, by the way, used both Windows 2000 professional and XP professional, in turns, during all of this work. Later in the booklet (see page 3 ff.) I will account for the problems, which are connected with the choice of Windows versions and hardware when working with sound and video.
In this section, we will be looking at all the existing forms of video recording and how they can be processed in a computer.
What is video
When we talk about video, we mean moving pictures taken with some sort of camera and shown on a screen of a kind. Video recordings consist of several and often many images, which are quickly shown one after the other. There can, for example, be 15 or 25 images per second. Video recordings also include sound, which is synchronised with the display of the images. The images and the sound go together.
Common for sound and images is that a stream of data runs through the computer’s hardware as long as the recording takes place and that they both have to be encoded in one or another format with or without compression.
Figure 118. Both sound and images are coded together for a video recording.
For private purposes there are:
These three forms of video can all be played on a computer and a computer can also to some degree process them.
Figure 119. The simplest form for video equipment for a computer is a webcam. Here is the “classical” sort, which is solely designed for installation on a computer’s screen.